Abstract:
Apparatus and method for detecting seal failure of a sealed region within a conveyor component. A fluid line extends out of the sealed region and a sensor is connected to the fluid line. A valve is connected subsequent to the sensor, and a fluid pump that is connected subsequent to the valve. A controller is connected to the sensor, the valve, and the fluid pump. The sensor is external to the sealed region and the valve is a solenoid valve. The sealed region is within an idler pulley that has a drum shell with an end lid affixed at an axial end thereof, and a shaft. The sealed region can be contained within a motorized drum or a hollow conveyor frame structure. A method detects seal failure by forming a sealed region bounded by a surface and a seal, and altering a fluid pressure, th time rate of change of which is monitored.

Description:
RELATIONSHIP TO OTHER APPLICATION(S) 
       [0001]    This application claims the benefit of the filing dates of: U.S. Provisional Patent Application Ser. No. 61/522,587, filed Aug. 11, 2011; U.S. Provisional Patent Application Ser. No. 61/590,790, filed Jan. 25, 2012; and U.S. Provisional Patent Application Ser. No. 61/665,888, filed Jun. 28, 2012, the disclosures of all of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates generally to high powered compact electric motors, and more particularly, to a motor and reducer system, the motor being an outer rotor motor that is particularly adaptable for motorized drums used in a conveyor or the like to drive a conveyor belt or the like around the drum shell, and more particularly to sanitary conveyor motorized drum applications. In addition, this invention relates to a sanitation system that monitors fluid pressures within high powered compact electric motors, as well as fluid pressures within conveyor rollers and supporting structures, the sanitation system being particularly adaptable to sanitary conveyor applications. 
         [0004]    2. Description of the Related Art 
         [0005]    Motorized drums are predominantly configured so that a motor and reducer are disposed within a drum shell and the rotations of the motor are reduced by the reducer and then transmitted to the drum shell so that when the external shafts are secured to the frame of a conveyor, the drum shell is able to rotate. In some embodiments, the drum shell drives a flat belt, or toothed belt, or modular belt. 
         [0006]    The motorized drum that is currently available has a drum shell and the motor and reducer are housed within this drum shell. Bearings and seals are disposed at both end sections of the drum shell with end covers for closing these end sections disposed between the bearings and the drum shell. Labyrinths are frequently used in the end covers to protect the seals from high pressure water that is used to clean food processing plants. There are employed first and second mounting shafts that enable rotation relative to the drum shell. Accordingly, the drum shell rotates about a central axis of the first and second mounting shafts. The first mounting shaft contains a hollow portion through which the motor wiring leads, which are connected to the motor, exit the motorized drum. The known motorized drum is partially filled with oil, which lubricates the open gear box and bearings, and transmits the heat from the motor to the inner periphery of the roller drum as the oil moves throughout the motorized drum. 
         [0007]    The known motor has an internal rotor with a shaft attached. This motor rotor shaft also functions as the input shaft for the reducer. The reducer has an output shaft that is coupled to the shell while the fixed reference point of the reducer (it&#39;s housing) rotates relative to the drum shell and has no rotary motion relative to the motor stator and mounting shafts. When the motor is energized, the shaft of the known motor rotates. The speed of this rotation is reduced by the reducer, and the reducer output power is then transmitted to the drum shell via the output shaft, thereby driving the drum shell into rotation. In order to achieve smooth operation, the central axis of the motor output shaft and the central axis of the first and second mounting shafts must be in substantial alignment with each other. 
         [0008]    The food processing industry is often a twenty four hour cycle that typically employs two shifts of production and one shift of cleaning. The focus is on high throughput, and downtime is not acceptable. Equipment failure must be repairable immediately or replaceable with spare parts. 
         [0009]    Existing motorized drums are essentially custom products. Four variables are involved in the selection of a motorized drum. These are: belt speed, belt width, belt pull, and pulley diameter. Additional options may also be included in the analysis, such as lagging, various electrical options, and the need for reinforced shafts. 
         [0010]    Currently, the industry predominantly uses AC induction motors that operate at a fixed speed. A motor speed and a gear reduction arrangement must be selected to provide the highest possible belt pull for the application, while creating the lowest amount of heat. The heat issue is critical as the motorized drum is a closed system that renders removal of heat to be very difficult. Therefore a large number of motors, in different poles, must be considered for each diameter along with multiple two and three stage gear boxes. 
         [0011]    Currently, the industry uses helical gearing that is limited by the diameter and axial length of the pulley. Therefore, to transmit the necessary torque through the gear box, it is often necessary to use a larger diameter pulley, which is usually not preferred by the market. 
         [0012]    In order to have the correct motorized drum available for each application, the manufacturer would need to stock thousands of possibilities, which is not financially feasible. Therefore, each motor is custom built based upon the four variables noted above, resulting in unacceptably long lead times to the industry. As zero downtime is a market requirement, the food processor customer must stock spares of all the motors he uses. This can be as many as several hundreds of motors, requiring high capital investment and cost. 
         [0013]    Therefore, it is an object of this invention to create a modular motorized drum that can eliminate the customer&#39;s need for a large spare parts inventory by means of a motorized drum produced in its minimal axial length (hereafter, base unit), that includes a mounting face system on one end of the motorized drum onto which various components can be mounted. Such components include end lids, additional extension drum shells and an extension shaft that can accommodate the attachment of sprockets, among others. 
         [0014]    It is a further object of this invention to increase the torque density of the motorized drum so that the modular base unit can be a single unit in a preferred diameter and axial length. 
         [0015]    It is another object of this invention to provide a motor that maintains a relatively constant torque and efficiency curve across a broad speed range so that a single base unit can be used in all applications within a given production plant. 
         [0016]    Customers require spares and spare parts because of the high likelihood of catastrophic failure present in the current art. One contributor to catastrophic failure among current art is the high belt pull and/or tension of the belt on the motorized drum that causes severe and immediate damage to the internal components. Existing motorized drums use segmented or partial shafts. A partial shaft is fixed to the conveyor and enters the motorized drum and is attached to a motor flange. The motor flange is attached to the motor, and the motor is attached to a gear box. The gear box is attached to a partial shaft that exits the motorized drum and is then affixed to the conveyor. These partial shaft segments are either substantially coaxial or are parallel with the motor shaft portion. The dividing of the shaft axially, however, diminishes the transaxial rigidity of the shaft, causing flexure and misalignment between the partial shafts and thus between the motor and transmission. 
         [0017]    Such misalignment creates inefficiency, high wear, and often catastrophic failure of the transmission or motor. Prior art efforts to alleviate this problem by include increasing the diameter of the first or second mounting shaft within the motorized drum as the axial length of the motorized drum increases. Others in the art have sought to compensate by using axially longer end lids. 
         [0018]    Therefore, it is an object of this invention to accommodate the misalignment between all components of the motorized drum and to accommodate, rather than minimize, the inherent forces causing deflection that enters the motorized drum. 
         [0019]    Another significant problem with existing art is its inability to comply fully with the food safety demands of the market. First, it is noted that existing products are filled with oil in order to lubricate gears, bearings, and seals. The oil also transmits heat from the motor core to the shell, where it can be removed by conduction to the belt. Further, system inefficiencies create heat and build pressure in the system, forcing the oil to leak through the rubber lip seals—especially where scoring has occurred in the shaft at the seal. Oil leakage creates the risk of contamination of the food products. 
         [0020]    Therefore, it is yet another object of this invention to eliminate the use of oil in the motorized drum. 
         [0021]    Second, it is a significant problem with existing motor designs that harborage points exist in the exterior of the drum unit wherein bacterial colonies (i.e., pathogens) can grow. Examples of efforts to alleviate this problem include the use of a labyrinth in the end lid that is used to protect rotary shaft seals from high pressure washing. Also, external bolts and washers are used to connect the end lids to the drum shell, and further bacterial harborage regions are present between the drum shell and its end lids. 
         [0022]    Therefore, it is a further object of the invention to eliminate harborage points where colonies of bacteria can flourish. 
         [0023]    Third, existing motorized drums that drive modular conveyor belting or toothed driven belting, predominantly engage the belting by means of grooved rubber or polyurethane lagging. This lagging will crack, lift, or pit, thereby not only creating additional harborage points for bacteria, but also serving to isolate heat within the motor. The result is that currently available motors must be derated typically by approximately 18%. This means that more heat is created in relationship to the work performed because the motor is now running at decreased efficiency. The lagging therefore causes the pulley to take a longer period of time to reach steady state, and when it does reach the steady state condition, it does so at a higher temperature than would have been the case without the polymeric lagging, ultimately resulting in higher belt temperature. This additional heat must then be removed from the lagging by the conveyor belt. As the conveyor belt moves along the conveyor, the heat typically is removed from the belt either by convection into the environment or through conduction into the food product being conveyed. It is desired by food industry personnel that no heat from the drive system enter into the food product. 
         [0024]    Other prior art arrangements drive modular conveyor belting or toothed driven belting by mounting sprockets to the drum shell instead of lagging. In such arrangements, the conveyor belt does not contact the drum shell directly, and therefore the drum motor still needs to be derated. Further, the sprockets, in their various mounting structures to the shell, create harborage points or dead spaces where bacterial colonies can grow. 
         [0025]    Therefore, it is an object of this invention to reduce the steady state temperature of the motorized drum. 
         [0026]    It is a further object of the invention to increase the rate of heat dissipation from the windings within the electrical motor to the inner surface of the drum shell. 
         [0027]    Fourth, the food industry is concerned about potential cross contamination between the materials within a motorized drum and the food products being conveyed. Thus, the industry continues to seek a solution that will announce the presence of conditions that produce a likelihood of cross contamination. For example, many food industry customers require that red or blue dyes be added to a food grade oil so that when oil leaks, it can be detected. This proposed solution is not reliably effective because after the motorized drum is operated for a period of time, the oil becomes black and the red or blue dye no longer functions as an alert. Additionally, even when there is no actual leakage of oil, cross contamination is still a threat because bacterial colonies will grow in a labyrinth or seal unnoticed, which can then be propelled onto the conveyor during performance of a high pressure cleaning procedure. 
         [0028]    Therefore, it is still another object of this invention not only to eliminate the use of oil in a closed system, but also to monitor the corruption of the rotary shaft seals and the static end lid seals in order to alert the system operator in a timely manner that the integrity of the seals has been compromised. 
       SUMMARY OF THE INVENTION 
       [0029]    The foregoing and other objects are achieved by this invention, which provides, in accordance with a first apparatus aspect of the invention, an apparatus for detecting seal failure of a sealed region within a conveyor component. In accordance with the invention, the apparatus has a fluid line extending out of the sealed region within the conveyor component. A sensor is connected to the fluid line, and a valve is connected to the fluid line subsequent to the sensor. There is additionally provided a fluid pump that is connected subsequent to the valve. A controller is connected to the sensor, the valve, and the fluid pump. 
         [0030]    In one embodiment, the sensor is external to the sealed region within a conveyor component. The valve in some embodiments of the invention is a solenoid valve. 
         [0031]    In an advantageous embodiment of the invention, the sealed region within a conveyor component is contained within an idler pulley. The idler pulley is provided with a drum shell and an end lid that is affixed to an axial end of the drum shell, and a shaft. 
         [0032]    In other embodiments, however, the sealed region within a conveyor component is contained within a motorized drum. The motorized drum is provided with a drum shell, and there is further provided a motor having a rotatory output, the motor being disposed within the drum shell. An end lid is additionally provided, as well as a shaft. 
         [0033]    In yet another embodiment the sealed region is contained within a hollow conveyor frame structure. 
         [0034]    In accordance with a method aspect of the invention, there is provided a method of detecting seal failure. The method includes the steps of: 
         [0035]    forming a sealed region within a conveyor component bounded by an element having a surface and a seal that communicates with a further surface; 
         [0036]    extending a fluid line out of the sealed region; 
         [0037]    altering a fluid pressure within the sealed region, thereby creating a pressure differential between the sealed region and a reference pressure value; and 
         [0038]    monitoring a pressure differential between the sealed region and the reference pressure value. 
         [0039]    In one embodiment of this method aspect, the calculated acceptable pressure differential change rate is a function of the gas permeability of the sealed region and the change in pressure differential expected due to expected changes in temperature differential between the sealed region and the ambient environment outside of the sealed region. When a pressure differential change rate exceeds the calculated acceptable pressure differential change rate, action is taken. 
         [0040]    In one embodiment of this method aspect, the reference pressure value corresponds to a fluid pressure of an ambient environment outside the sealed region. In other embodiments, however, the reference pressure value is adjustable. 
         [0041]    The method of the invention includes the step of withdrawing a fluid from the sealed region at a determinable rate of fluid withdrawal, whereby the fluid pressure in the sealed region is made lower than the reference pressure value. In a practicable embodiment, the determinable rate of fluid withdrawal is determined as a function of the physical and environmental characteristics of the seal. In some embodiments, the physical and environmental characteristics of the seal and sealed region are responsive to temperature variation and gas permeability. 
         [0042]    Further in accordance with the invention, are provided the steps of monitoring a fluid pressure level in the sealed region and determining a time rate of change of the fluid pressure level in the sealed region. An aspect of this embodiment is the step of identifying an excessive rate of change of the fluid pressure level in the sealed region. 
         [0043]    In some embodiments, there is provided the step of increasing the rate of withdrawal of the fluid from the sealed region over the predeterminable rate. This ensures that when a fault condition is detected, the reduced pressure greatly diminishes the likelihood that bacteria, debris, or any other contaminant will exit the sealed region. In some embodiments, the step of increasing the rate of withdrawal of the fluid from the sealed region includes the step of varying a reference pressure value. 
         [0044]    In other embodiments, there is provided the step of monitoring a rate of fluid flow in the fluid line wherein the monitoring of pressure differential is accomplished by monitoring the rate of fluid flow in the fluid line. In some embodiments, the implementation of this step utilizes one or more fluid lines that have predetermined flow rate versus pressure characteristics, whereby the correlation between flow rate and pressure is known. In some such embodiments, when the rate of fluid flow in the fluid line exceeds a predetermined rate of fluid flow, a seal fault condition is indicated. In some embodiments, when the seal fault condition is indicated, there is provided the further step of increasing the rate of fluid flow to maintain a reduced fluid pressure in the sealed region. 
         [0045]    In still other embodiments of the invention, there are provided the steps of: 
         [0046]    inserting a fluid into the sealed region, whereby the pressure in the sealed region is made greater than the reference pressure value; 
         [0047]    monitoring a variation in the fluid pressure within the sealed region; 
         [0048]    determining a time rate of change of the variation in the fluid pressure within the sealed region; and 
         [0049]    identifying a fault condition in response to the step of determining a time rate of change of the variation in the fluid pressure. 
         [0050]    In a practicable embodiment of the invention, the sealed region is contained within an idler pulley that includes a drum shell of the idler pulley, an end lid that is affixed to an axial end of the drum shell, and a shaft. 
         [0051]    In a further embodiment, the sealed region is contained within a motorized drum that includes a drum shell, a motor disposed inside the drum shell, an end lid, and a shaft. 
         [0052]    In a still further embodiment, the sealed region is contained within a hollow conveyor frame structure. 
         [0053]    In some embodiments that employ a central shaft, there is provided the step of extending a fluid line out of the sealed region through the central shaft of the idler pulley. Such would be the case where the fluid line is extended out of the sealed region through the central shaft of the motorized drum. In addition to a fluid line, in some embodiments the is provided the further step of extending electrical wires through the central shaft of the motorized drum. 
         [0054]    In another embodiment, there are provided the steps of: 
         [0055]    coupling the fluid line to a sensor; 
         [0056]    further coupling the fluid line to a valve subsequent to the sensor; and 
         [0057]    subsequently coupling the valve to a pump, to enable the displacement of fluid between the sealed chamber and ambient environment and to enable measurement of the pressure differential between the sealed region and the ambient environment. In some such embodiments, the sensor is an external sensor and the valve is a solenoid valve. 
         [0058]    The method of operation of such an embodiment includes the steps of: 
         [0059]    activating the pump and opening the valve accomplishes a fluid transfer; and 
         [0060]    closing the valve, whereupon the sensor is isolated from the pump, enables the sensor to measure the pressure in the sealed chamber. 
         [0061]    In still further embodiments, there are provided the steps of: 
         [0062]    mounting a sensor internal to the sealed region; 
         [0063]    extending a fluid line out of the sealed region; 
         [0064]    coupling the fluid line to a valve; and 
         [0065]    subsequently coupling the valve to a pump, to enable the displacement of fluid between the sealed region and ambient environment and to enable measurement of the pressure differential between the sealed region and the ambient environment. 
         [0066]    In accordance with a further method aspect of the invention, there is provided a method of detecting seal failure of an enclosure having a portion thereof sealed with a seal. The method includes the steps of: 
         [0067]    measuring a fluid pressure within the enclosure; 
         [0068]    producing a pressure-responsive signal responsive to the step of measuring the pressure within the enclosure; and 
         [0069]    monitoring a variation in time of an amplitude characteristic of the pressure-responsive signal. 
         [0070]    In one embodiment of this further method aspect of the invention, there is further provided the step of subjecting the pressure-responsive signal to a transformation process for forming a frequency domain pressure-responsive electrical signal. In an embodiment wherein the enclosure is provided with a plurality of portions sealed with respective seals, and there is provided the step of identifying a failed one of the respective seals in response to the frequency domain pressure-responsive electrical signal. 
         [0071]    In some embodiments, the step of measuring a fluid pressure includes the step of installing a fluid pressure sensor within the enclosure. 
         [0072]    In other embodiments, there is provided the step of withdrawing a fluid from the enclosure in response to the step of monitoring a variation in time of an amplitude characteristic of the electrical signal. 
         [0073]    In accordance with a still further method aspect of the invention, there is provided a method of detecting seal failure of an enclosure having a portion thereof sealed with a seal. The method includes the steps of: 
         [0074]    introducing a fluid into the enclosure at a determinable rate of fluid introduction; 
         [0075]    removing a fluid from the enclosure at a determinable rate of fluid withdrawal; 
         [0076]    producing a differential electrical signal responsive to the difference between the rate of fluid introduction and the rate of fluid withdrawal. 
         [0077]    In one embodiment of this still further method aspect of the invention. there is provided the step of measuring a fluid pressure within the enclosure. There is additionally provided the step of monitoring a variation in time of an amplitude characteristic of the differential electrical signal. In some embodiments, this includes the step of subjecting the differential electrical signal to a transformation process for forming a frequency domain differential electrical signal. In embodiments where the enclosure is provided with a plurality of portions sealed with respective seals, there is provided the step of identifying a failed one of the respective seals in response to the frequency domain differential electrical signal. 
         [0078]    In accordance with a still further method aspect of the invention, there is provided a method of detecting seal failure of a conveyor component having a portion thereof sealed with a seal, an external sensor, a valve, a pump and a controller. 
         [0079]    The external sensor, the valve and the pump are all connected to a controller running a sensing logic sequence, which runs on a predetermined schedule, said sequence logic including the following steps: 
         [0080]    performing a first test pressure measurement when the valve is closed; 
         [0081]    verifying that the first test pressure measurement is within determined parameters; 
         [0082]    waiting for a predetermined period of time to expire; 
         [0083]    performing a second test pressure measurement of the sealed chamber; 
         [0084]    verifying that the second test pressure measurement is within determined parameters; and 
         [0085]    calculating a variation between the first and second test pressure measurements by subtracting the second measurement from the first measurement; 
         [0086]    determining a rate of pressure variation over the predetermined period of time; and 
         [0087]    correlating the rate of pressure variation against a maximum allowable pressure variation. 
         [0088]    If any of the results of the foregoing steps is outside of the associated determined parameter, then: 
         [0089]    activate pump; 
         [0090]    open valve; 
         [0091]    wait for a predetermined time to lapse, during which time the valve can be cycled and measurements can be taken to ensure the sealed chamber is not excessively evacuated; 
         [0092]    take a second test measurement while the pump is still active and the valve is open to verify there is no malfunction of the pump or valve; 
         [0093]    if the second test pressure measurement is valid, take a third test measurement when the valve is closed, wherein an initial pressure measurement of the sealed chamber is taken to verify that the measurement of pressure is adequate; 
         [0094]    wait a predetermined period of time; 
         [0095]    take a second test measurement while the pump is still active and the valve is open to verify there is no malfunction of the pump or valve; 
         [0096]    if the second test measurement is valid, take a third test pressure measurement when the valve is closed, wherein an initial pressure measurement of the sealed chamber is taken to verify that the measurement of pressure is adequate; 
         [0097]    wait a predetermined period of time; 
         [0098]    take a second initial pressure measurement of the sealed chamber to verify that the measurement of under-pressure is still adequate; and 
         [0099]    calculate the variation in pressure by subtracting the second measurement from the first measurement and dividing by the lapse in time between the first and second measurements, to verify that the rate of the pressure variation is within determined parameters. 
         [0100]    If any of the steps in the second measurement test fail, an alert notification procedure is then performed, which in some embodiments includes leaving the solenoid open and the pump running at a higher flow rate so as to create a continuous negative pressure condition and thereby ensure that contaminates are not able to exit the motorized drum. 
         [0101]    In yet another method aspect of the invention, there is provided a method of cleaning a region of a rotary seal that is interposed between a housing and a shaft. The method includes the steps of: 
         [0102]    forming an annular chamber bounded by first and second rotary seals, a spacer element for maintaining the first and second rotary seals axially apart for a predetermined axial distance, and the shaft; 
         [0103]    forming inlet and outlet ports, the inlet and outlet ports communicating with the annular chamber; 
         [0104]    delivering a cleaning fluid to the annular chamber via the inlet port; and 
         [0105]    extracting the cleaning fluid from the annular chamber via the outlet port. 
         [0106]    In one embodiment, the inlet and outlet ports are formed through the shaft. 
         [0107]    A embodiment of the invention includes the step of pressurizing the annular chamber with the cleaning fluid. This includes the step of increasing the pressure of the cleaning fluid in the annular chamber to a level where cleaning fluid escapes past one of the first and second rotary seals. In an advantageous embodiment the first and second rotary seals are lip seals having respective directional pressure-resisting characteristics. The first and second rotary seals are axially oriented to ensure that cleaning fluid escapes out of the annular chamber escapes toward the exterior of the housing. 
         [0108]    In accordance with another apparatus aspect of the invention, a conveyor roller has a drum shell and a shaft. The cleaning system for a rotary seal region includes first and second rotary seals that are arranged to communicate sealingly with the shaft. A spacer element maintains a determined axial distance between the first and second rotary seals. Thus, an annular chamber is formed bounded by the first and second rotary seals, the spacer element, and the shaft. there is additionally provided an inlet port for delivering a cleaning fluid to the annular chamber, and an outlet port for extracting the cleaning fluid from the annular chamber. 
         [0109]    In an advantageous embodiment of the invention the inlet and outlet ports are disposed through the shaft. In a practicable embodiment of the invention, the first and second rotary seals have directional pressure-resisting characteristics, as would be the case with rotary lip seals. 
         [0110]    In embodiments where the conveyor roller is a motorized drum having a motor disposed inside the drum shell, the drum shell is rotatable around the shaft. 
         [0111]    In accordance with another method aspect of the invention, there is provided a method for minimizing egress of contaminants from within a conveyor component due to a seal failure. The method includes the steps of: 
         [0112]    forming a sealed area in a conveyor component bounded by one or more elements having a surface and one or more seals that communicate with one or more surfaces; 
         [0113]    extending a fluid line out of said sealed region; 
         [0114]    connecting said fluid line to a pump; and 
         [0115]    withdrawing some fluid from within said sealed region, thereby creating a negative pressure within said sealed region. 
         [0116]    In some embodiments the conveyor component is an idler pulley. In other embodiments the conveyor component is a motorized drum or a conveyor frame. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0117]    Comprehension of the invention is facilitated by reading the following detailed description, in conjunction with the annexed drawing, in which: 
           [0118]      FIG. 1  is a simplified schematic representation of a conventional motorized drum; 
           [0119]      FIG. 2  is a simplified schematic representation of another conventional motorized drum; 
           [0120]      FIG. 3(   a ) is a simplified end view of an embodiment of the motorized drum of the present invention with a partial cut away showing the key inserted in the central shaft for engaging the high torque coupler. 
           [0121]      FIG. 3(   b ) is an axial cross-section of a motorized drum of a particular embodiment of the present invention, wherein an external rotor is connected to a cycloidal reducer utilizing a hollow bore input shaft within a drum shell, and wherein an extension shell component with integrated sprocket geometry is attached to the mounting face of the base unit; 
           [0122]      FIG. 3(   c ) is a simplified section view across A-A of  FIG. 3B , showing the mounting face; 
           [0123]      FIG. 4  is an axial cross-section of a motorized drum of a particular illustrative embodiment demonstrating some of the aspects of the present invention, wherein an external rotor is connected to a cycloidal reducer utilizing a central input shaft within a drum shell; 
           [0124]      FIG. 5  is an enlargement of the portion B-B of the simplified schematic cross-sectional representation of the embodiment of  FIG. 4 ; 
           [0125]      FIG. 6  is a simplified schematic cross-sectional representation of a portion of the stator of an outer rotor induction motor embodiment of the invention having twenty-four slots; 
           [0126]      FIG. 7  is an enlargement of a fragmented portion of the simplified schematic cross-sectional representation of the of the stator embodiment of  FIG. 6  showing two of the twenty-four slots in greater detail; 
           [0127]      FIG. 8  is a simplified schematic cross-sectional representation of a rotor of the outer rotor induction motor embodiment of the present invention having thirty-two substantially round-shaped slots; 
           [0128]      FIG. 9  is an enlargement of a portion of the simplified schematic cross-sectional representation of the rotor embodiment of  FIG. 8  showing one of the thirty-two substantially round-shaped slots in greater detail; 
           [0129]      FIG. 10  is a simplified schematic cross-sectional representation of rotor bars that are inserted through the substantially round-shaped slots of the rotor arrangement of  FIGS. 7 and 8  and are fixed within an end-ring without requiring die-casting; 
           [0130]      FIG. 11  is a simplified schematic representation of a winding distribution useful in the practice of the present invention; 
           [0131]      FIG. 12  is a simplified magnetic flux diagram of an induction motor that illustrates the tight linkage between the stator and rotor under load conditions that is achieved by a specific illustrative embodiment of the invention; 
           [0132]      FIG. 13(   a ) is a simplified schematic cross-sectional representation of a permanent magnet motor utilizing an outer turning rotor with magnets embedded within the rotor laminations; 
           [0133]      FIG. 13(   b ) is a cross-sectional representation of the outer turning rotor lamination showing the bolt holes in the center of each magnet polarity pair; 
           [0134]      FIG. 14(   a ) is a simplified magnetic flux diagram of a interior permanent magnet synchronous motor, utilizing an outer turning rotor.  14 ( b ) is an enlarged view of the magnetic flux at the point where north south magnets are in close proximity; 
           [0135]      FIG. 15 . is a simplified schematic isometric representation of a permanent magnet rotor system having a permanent magnet rotor housing in which a plurality of permanent magnet elements are arranged in a spiral configuration; 
           [0136]      FIG. 16  is a simplified schematic end plan representation of the permanent magnet rotor housing embodiment of  FIG. 15 ; 
           [0137]      FIG. 17  is a simplified schematic representation of section A-A of the permanent magnet rotor housing embodiment of  FIG. 16 ; 
           [0138]      FIG. 18  is a simplified schematic representation of an axial cross-section through an external rotor with a drum shell that is particularly suited for use in a motorized drum, and this is useful to describe the flow of cooling gas in a single centrifugal impeller embodiment of the invention; 
           [0139]      FIG. 19  is a cross-section through a conventional cycloidal speed reducer, which is commonly mounted to a standard external motor; 
           [0140]      FIG. 20  is a cross-section through a cycloidal speed reducer of the present invention, which is mounted within a motorized drum; 
           [0141]      FIG. 21  is a simplified schematic representation of a motorized drum utilizing a harmonic speed reducer with a hollow bore input, wherein the major axis of the wave generator is in the horizontal position; 
           [0142]      FIG. 22  is a simplified schematic representation of a motorized drum utilizing a harmonic speed reducer with a hollow bore input, wherein the major axis of the wave generator is in the vertical position; 
           [0143]      FIG. 23  is a simplified isometric representation of the hollow bore input of the cycloidal reducer of the present invention, utilizing protruding tabs to receive motor input and utilizing integral eccentric raceways to engage input gears; 
           [0144]      FIG. 24  is another simplified isometric representation of the hollow bore input of the cycloidal reducer of the present invention, utilizing protruding tabs to receive motor input and utilizing integral eccentric raceways to engage input gears; 
           [0145]      FIG. 25  a simplified partially exploded isometric schematic representation of the coupling between the outer rotor of an electric motor, a cycloidal speed reducer, and a central shaft of an embodiment of the invention. 
           [0146]      FIG. 26(   a ) is a simplified schematic representation of a side plan view of a motorized drum constructed in accordance with the invention;  FIG. 26(   b ) is a plan cross-sectional representation of a shaft coupler; and  FIG. 26(   c ) is an end view of the motorized drum; 
           [0147]      FIG. 27  is a simplified schematic partially cross-sectional side plan representation of the embodiment of  FIGS. 26(   a ),  26 ( b ), and  26 ( c ) taken along section A-A of  FIG. 26(   a ) and showing the coupling between the elements of the structure there within; 
           [0148]      FIG. 28  is a simplified schematic representation of the coupling between the rotor of an electric motor, a cycloidal speed reducer, and a central shaft of an embodiment of the invention, wherein the high speed coupler has two slot pairs; 
           [0149]      FIG. 29  is a simplified partially exploded isometric schematic representation of the coupling system between the rotor of an electric motor, a cycloidal speed reducer, and a central shaft of an embodiment of the invention, wherein the high speed coupler has two slot pairs; 
           [0150]      FIG. 30  is a further simplified partially exploded isometric schematic representation of the coupling system between the rotor of an electric motor, a cycloidal speed reducer, and a central shaft of an embodiment of the invention, wherein the high speed coupler has two slot pairs; 
           [0151]      FIG. 31  is an alternate simplified partially exploded isometric schematic representation of the coupling system between the rotor of an electric motor, a cycloidal speed reducer, and a central shaft of an embodiment of the invention, wherein the high speed coupler has two tab pairs instead of slots; 
           [0152]      FIG. 32  is an alternate simplified partially exploded isometric schematic representation of the coupling system between the rotor of an electric motor, a cycloidal speed reducer, and a central shaft of an embodiment of the invention, wherein the high speed coupler has one pair of tabs and one pair of slots; 
           [0153]      FIG. 33  is an alternate simplified partially exploded isometric schematic representation of the coupling system between the rotor of an electric motor, a cycloidal speed reducer, and a central shaft of an embodiment of the invention, wherein the high speed coupler has a tab paired with a slot; 
           [0154]      FIG. 34  is an alternate simplified partially exploded isometric schematic representation of the coupling system between the rotor of an electric motor and a cycloidal speed reducer of an embodiment of the invention, wherein the high speed coupler has slot pair in the horizontal axis with a tab/slot paired in the vertical axis; 
           [0155]      FIG. 35  is an alternate simplified partially exploded isometric schematic representation of the coupling system between the rotor of an electric motor, a cycloidal speed reducer, and a central shaft of an embodiment of the invention, wherein a keyless bushing engages the central shaft rather than keys directly inserted into the central shaft; 
           [0156]      FIG. 36  is an axial cross-section of a motorized drum of an embodiment of the present invention, wherein an extension shaft is mounted to the mounting face of the base unit; 
           [0157]      FIG. 37  is an axial cross-section of a motorized drum of an embodiment of the present invention, wherein the clamp ring of the extension shaft is in direct contact with the mounting ring of the base unit, without the use of an intervening mounting face; 
           [0158]      FIG. 38  is an axial cross-section of a motorized drum of a particular embodiment of the present invention, wherein an extension shell component is attached to the mounting face of the base unit and held in place by means of a large central nut; 
           [0159]      FIG. 39  is an isometric exploded view of the mounting face system utilized in attaching extension shell components to the base unit of a motorized drum, as an embodiment of the present invention; 
           [0160]      FIG. 40  is an isometric representation of an embossed spring band; 
           [0161]      FIG. 41  is an isometric cut-away of one embodiment of the embossed spring band holding the end lid against the motorized drum of the present invention; 
           [0162]      FIG. 42(   a ) is a simplified cross-sectional representation of an embodiment of the compression geometry utilized in the end lid where the end lid contacts the static drum shell seal in the motorized drum of the present invention and  FIG. 42(   b ) is a simplified cross-sectional representation of an embodiment of the compression geometry utilized in the end lid where the end lid contacts the static drum shell seal in the motorized drum of the present invention in response to the application of an installation force, the end lid remaining in fixed relation by operation of an embossed band that is deformed upon installation; 
           [0163]      FIG. 43  is an axial simplified cross-sectional representation of the end lid of the motorized drum of the present invention in one embodiment, wherein the end lid has a relatively thin wall in the radial distance between the embossed spring band  03420  and the outer periphery in order to maximize the spring-like characteristics of the end lid against the static drum seal; 
           [0164]      FIG. 44  is a simplified cross-sectional representation of one embodiment of the compression geometry utilized in the end lid where the end lid contacts the rotary shaft seal of a motorized drum of the present invention; 
           [0165]      FIG. 45  is a cut away of an exploded view of one embodiment of the rotary shaft seal compression system of a motorized drum of the present invention; 
           [0166]      FIG. 46  is an isometric drawing of the end lid removal tool, as it is attached to the end lid of the motorized drum of the present invention; 
           [0167]      FIG. 47  is an isometric exploded view of  FIG. 46 ; 
           [0168]      FIG. 48  is a simplified schematic representation of a specific illustrative embodiment of a fluid port that is useful in the sanitation of the motor using selectably evacuation or pressurization within the motor as well as a pair of fluid ports used to cycle cleaning fluids through an annular chamber in the seal region of the motorized drum of the present invention; and 
           [0169]      FIG. 49  is a simplified schematic of a fluid port system useful in the sanitation of the motorized drum of the present invention, and more particularly in monitoring the state of the seals. 
           [0170]      FIG. 50  is an axial cross-section of a motorized drum of a particular embodiment of the present invention, wherein an extension shell component is attached to the mounting face of the base unit using clamping bolts and the drum shell of the base unit has a chamfer that mates with a corresponding chamfer on the extension drum shell. 
       
    
    
     DETAILED DESCRIPTION 
       [0171]    The following designations of items in the drawings are employed in the following detailed description: 
         [0000]    
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Item # 
                 Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 03000 
                 Motorized drum 
               
               
                 03010 
                 Base unit 
               
               
                 03100 
                 Cycloidal Reducer 
               
               
                 03110 
                 Hollow bore eccentric input 
               
               
                 03140 
                 Cycloidal disk (external toothed gear) 
               
               
                 03150 
                 Primary guide pin support ring 
               
               
                 03151 
                 Secondary guide pin support ring 
               
               
                 03153 
                 Guide pin bushing 
               
               
                 03160 
                 Cycloidal reducer housing (internal toothed ring gear) 
               
               
                 03161 
                 Ring pin 
               
               
                 03200 
                 Motor (Permanent magnet) 
               
               
                 03210 
                 Central shaft 
               
               
                 03220 
                 Stator 
               
               
                 03221 
                 Stator laminations 
               
               
                 03222 
                 Stator windings 
               
               
                 03223 
                 Stator winding leads 
               
               
                 03230 
                 Rotor 
               
               
                 03231 
                 First rotor bearing 
               
               
                 03232 
                 Second rotor bearing 
               
               
                 03233 
                 Primary rotor end lid 
               
               
                 03234 
                 Secondary rotor end lid 
               
               
                 03241 
                 Rotor laminations 
               
               
                 03242 
                 Rotor lamination clamp bolt 
               
               
                 03247 
                 Rotor output tab 
               
               
                 03310 
                 High speed coupler 
               
               
                 03350 
                 High torque coupler 
               
               
                 03351 
                 High torque central shaft key 
               
               
                 03410 
                 Primary end lid 
               
               
                 03420 
                 Embossed spring band 
               
               
                 03430 
                 End lid mounting face 
               
               
                 03440 
                 Seal compression plate 
               
               
                 03441 
                 Fastener 
               
               
                 03442 
                 Rotary polymeric lip seal 
               
               
                 03450 
                 Static polymeric seal 
               
               
                 03510 
                 Mounting ring 
               
               
                 03511 
                 Primary spring ring 
               
               
                 03512 
                 Mounting face 
               
               
                 03520 
                 Extension clamp spacer 
               
               
                 03530 
                 Clamp ring 
               
               
                 03531 
                 Secondary spring ring 
               
               
                 03532 
                 Extension clamping bolt 
               
               
                 03533 
                 Mating cam face washers 
               
               
                 03534 
                 Bolt holder 
               
               
                 03540 
                 Seal compression plate 
               
               
                 03541 
                 Fastener 
               
               
                 03542 
                 Rotary polymeric lip seal 
               
               
                 03560 
                 Extension shell attachment 
               
               
                 03570 
                 End lid attachment 
               
               
                 03571 
                 Embossed spring band 
               
               
                 03572 
                 Static seal 
               
               
                 03700 
                 Drum shell 
               
               
                 03710 
                 First base unit bearing 
               
               
                 03711 
                 Second base unit bearing 
               
               
                 04000 
                 Motorized drum 
               
               
                 04111 
                 Eccentric input shaft 
               
               
                 04140 
                 Cycloidal disk (external toothed gear) 
               
               
                 04152 
                 Guide pin 
               
               
                 04153 
                 Guide pin bushing 
               
               
                 04160 
                 Cycloidal reducer housing (internal toothed ring gear) 
               
               
                 04161 
                 Ring pin 
               
               
                 04200 
                 Motor (Induction) 
               
               
                 04210 
                 Stator shaft 
               
               
                 04220 
                 Stator 
               
               
                 04221 
                 Stator laminations 
               
               
                 04230 
                 Rotor 
               
               
                 04231 
                 First rotor bearing 
               
               
                 04232 
                 Second rotor bearing 
               
               
                 07224 
                 Stator slots 
               
               
                 07225 
                 Stator slots 
               
               
                 07226 
                 Stator winding retaining hook 
               
               
                 08235 
                 Rotor slot 
               
               
                 1010 
                 Inner turning rotor 
               
               
                 1020 
                 Helical gear reducer housing 
               
               
                 10236 
                 Rotor bar 
               
               
                 1030 
                 First partial shaft 
               
               
                 1040 
                 Motor housing 
               
               
                 1050 
                 Motor flange 
               
               
                 1060 
                 Second partial shaft 
               
               
                 1070 
                 Drum shell 
               
               
                 11224 
                 Stator wire portion 
               
               
                 11225 
                 Stator wire portion 
               
               
                 11226 
                 Stator wire portion 
               
               
                 11227 
                 Stator wire portion 
               
               
                 13243 
                 Embedded north rotor magnets 
               
               
                 13244 
                 Embedded south rotor magnets 
               
               
                 13246 
                 Rotor lamination bolt hole 
               
               
                 15245 
                 Rotor magnets - surface mounted 
               
               
                 18233 
                 Primary rotor end lid 
               
               
                 18234 
                 Secondary rotor end lid 
               
               
                 18240 
                 Rotor fins 
               
               
                 18249 
                 Air flow loop 
               
               
                 19100 
                 Cycloidal Reducer 
               
               
                 19111 
                 Eccentric input shaft 
               
               
                 19140 
                 Cycloidal disk (external toothed gear) 
               
               
                 19141 
                 Aperture 
               
               
                 19152 
                 Guide pin 
               
               
                 19153 
                 Guide pin bushing 
               
               
                 19160 
                 Cycloidal reducer housing (internal toothed ring gear) 
               
               
                 19161 
                 Ring pin 
               
               
                 19162 
                 Ring pin bushing 
               
               
                 2010 
                 Inner turning rotor motor 
               
               
                 20100 
                 Cycloidal Reducer 
               
               
                 20110 
                 Hollow bore eccentric input 
               
               
                 20140 
                 Cycloidal disk (external toothed gear) 
               
               
                 20141 
                 Aperture 
               
               
                 20152 
                 Guide pin 
               
               
                 20153 
                 Guide pin bushing 
               
               
                 20160 
                 Cycloidal reducer housing (internal toothed ring gear) 
               
               
                 20161 
                 Ring pin 
               
               
                 20162 
                 Ring pin bushing 
               
               
                 2020 
                 Cycloidal speed reducer 
               
               
                 2030 
                 First partial shaft 
               
               
                 2040 
                 Motor housing 
               
               
                 2050 
                 Support flange 
               
               
                 2060 
                 Second partial shaft 
               
               
                 21000 
                 Motorized drum 
               
               
                 21800 
                 Harmonic speed reducer 
               
               
                 21810 
                 Wave generator 
               
               
                 21811 
                 Elliptical ball bearing 
               
               
                 21820 
                 Flexible spline 
               
               
                 21830 
                 Rigid circular spline 
               
               
                 21831 
                 Affixing pin 
               
               
                 23120 
                 Hollow bore eccentric raceway 
               
               
                 23130 
                 Hollow bore eccentric input tab 
               
               
                 27110 
                 Cycloidal reducer input 
               
               
                 27150 
                 Cycloidal reducer fixed reference 
               
               
                 27160 
                 Cycloidal reducer output 
               
               
                 27410 
                 End lid 
               
               
                 31130 
                 Hollow bore eccentric input slot 
               
               
                 31248 
                 Rotor output slot 
               
               
                 31310 
                 High speed coupler - first alternate 
               
               
                 32310 
                 High speed coupler - second alternate 
               
               
                 33131 
                 Hollow bore eccentric input tab 
               
               
                 33132 
                 Hollow bore eccentric input slot 
               
               
                 33310 
                 High speed coupler - third alternate 
               
               
                 35210 
                 Central shaft 
               
               
                 35311 
                 High speed coupler orthogonal driving face 
               
               
                 35312 
                 High speed coupler orthogonal driving face 
               
               
                 35313 
                 High speed coupler orthogonal driving face 
               
               
                 35314 
                 High speed coupler orthogonal driving face 
               
               
                 35315 
                 High speed coupler orthogonal driving face 
               
               
                 35316 
                 High speed coupler orthogonal driving face 
               
               
                 35317 
                 High speed coupler orthogonal driving face 
               
               
                 35318 
                 High speed coupler orthogonal driving face 
               
               
                 35350 
                 High torque coupler 
               
               
                 35352 
                 High torque keyless bushing 
               
               
                 35353 
                 High torque key ring 
               
               
                 36000 
                 Motorized drum 
               
               
                 36513 
                 Mounting ring alignment bolt 
               
               
                 36530 
                 Clamp ring 
               
               
                 36532 
                 Extension clamping bolt 
               
               
                 36560 
                 Extension shaft attachment 
               
               
                 37000 
                 Motorized drum 
               
               
                 37510 
                 Mounting ring 
               
               
                 37511 
                 Primary spring ring 
               
               
                 37530 
                 Clamp ring 
               
               
                 37560 
                 Extension shaft attachment 
               
               
                 38530 
                 Clamp ring 
               
               
                 38550 
                 Threaded flange 
               
               
                 38551 
                 Central nut 
               
               
                 46900 
                 End lid Removal Tool 
               
               
                 46910 
                 Joining cord 
               
               
                 46920 
                 Recessed, outer circumferential geometry 
               
               
                 46930 
                 Recessed, inner circumferential geometry 
               
               
                 46940 
                 End tool clamp 
               
               
                 46950 
                 Slide hammer 
               
               
                 48000 
                 Motorized drum 
               
               
                 48210 
                 Central shaft 
               
               
                 48540 
                 Seal compression plate 
               
               
                 48541 
                 Seal spacer ring 
               
               
                 48570 
                 End lid attachment 
               
               
                 48610 
                 First cleaning conduit 
               
               
                 48611 
                 Second cleaning conduit 
               
               
                 48612 
                 Fluid conduit 
               
               
                 48613 
                 Annular chamber 
               
               
                 48614 
                 Dead space 
               
               
                 48615 
                 Motorized drum chamber 
               
               
                 48620 
                 Inlet port 
               
               
                 48621 
                 Outlet port 
               
               
                 48622 
                 Fluid port 
               
               
                 48630 
                 Polymeric radial seal 
               
               
                 48631 
                 Polymeric radial seal 
               
               
                 48632 
                 Polymeric radial seal 
               
               
                 49100 
                 Fluid line 
               
               
                 49200 
                 Sensor 
               
               
                 49300 
                 Controller 
               
               
                 49400 
                 Valve 
               
               
                 49500 
                 Pump 
               
               
                 50450 
                 Chamfer 
               
               
                 50510 
                 Mounting ring 
               
               
                 50511 
                 Spring ring 
               
               
                 50512 
                 Mounting face 
               
               
                 50530 
                 Clamp ring 
               
               
                 50531 
                 Spring ring 
               
               
                 50532 
                 Clamping bolt 
               
               
                 50560 
                 Extension shell attachment 
               
               
                 50700 
                 Drum shell 
               
               
                   
               
             
          
         
       
     
         [0172]      FIG. 1  is a simplified schematic representation of a prior art motorized drum that utilizes an inner turning rotor motor  1010 , a helical gear reducer  1020  and a first partial shaft  1030  connected to the helical gear reducer housing  1020 , which is connected to the motor housing  1040 . Motor housing  1040  is connected to a motor housing flange  1050 , which is connected to a second partial shaft  1060 . This motorized drum is a closed, oil-filled, thermal system utilizing the oil (not shown) to transfer motor heat (not shown) to drum shell  1070 . 
         [0173]      FIG. 2  is a simplified schematic representation of a prior art motorized drum that utilizes an inner turning rotor motor  2010 , a cycloidal reducer  2020  and a first partial shaft  2030  that is connected to the housing (not specifically designated) of cycloidal reducer  2020 . The housing of cycloidal reducer  2020  is connected to a motor stator housing (not specifically designated) and a support flange  2050  that encompasses the motor. Support flange  2050  is further connected to a second partial shaft  2060 . 
         [0174]    This motorized drum is an open thermal system, utilizing external air (shown by curved arrows), which is urged into the motorized drum and flows across the motor and reducer and exits the opposite end of the motorized drum, to transfer the motor heat into the ambient environment. 
         [0175]      FIG. 3(   b ) is a side plan axial cross-sectional representation of a motorized drum  03000  constructed as a specific illustrative embodiment of the invention of the present invention. In this embodiment, the radially interior periphery of external rotor  03230  rotates about the radially exterior stator  03220  and is connected to a cycloidal reducer  03100  utilizing a hollow bore input shaft  03110  within a drum shell  03700 , and wherein an extension shell attachment  03560  is attached to the mounting face  03512  of base unit  03010 . 
         [0176]    The motorized drum  03000  of the present invention comprises a drum shell  03700  and the motor  03200  and cycloidal reducer  03100  are housed inside of drum shell  03700 . Bearings  03710 ,  03711  are disposed at both end sections of the drum shell on the central shaft  03210  thereby constituting the base unit  03010 . In this embodiment, an extension shell attachment  03560  is mounted to the mounting face  03512  on the right side of the base unit  03010 . The base unit  03010  plus the mounted extension shell attachment  03560  are sealed forming a closed thermal system. 
         [0177]    The motor output, which is a pair of tabs  03247  on the rotor  03230 , is coupled to the cycloidal reducer input  03110 , by means of a high speed coupler  03310  thus reducing the speed and increasing the torque. The cycloidal housing, which is an internal toothed ring gear  03160 , is directly connected to drum shell  03700  so that the drum shell rotates about fixed central shaft  03210 . 
         [0178]    Stator  03220  of motor  03200  is affixed to central shaft  03210 . The central shaft and stator winding leads  03223  pass through the center of the hollow bore eccentric input  03110  of the cycloidal reducer  03100  with sufficient clearance to accommodate the deflection that central shaft  03210  will experience in operation. Outer turning rotor  03230  is mounted to central shaft  03210  by means of rotor bearings  03231  and  03232 . 
         [0179]    The fixed reference point of the cycloidal reducer  03100  is affixed to central shaft  03210  by a high torque coupler  03350  and high torque central shaft key  03351  ( FIG. 3   a ). 
         [0180]    A primary end lid  03410  is attached to the base unit  03010  by means of an embossed spring band  03420  and an end lid mounting face  03430 . 
         [0181]      FIGS. 4 through 12  relate to an embodiment of the present invention, wherein the outer turning rotor is of an induction motor.  FIG. 4  is a simplified axial cross-section through a motorized drum  04000  wherein a motor  04200  has an external rotor  04230  constructed in accordance with the principles of one embodiment of the invention. Outer turning rotor  04230  improves the torque density of the motor, whereby the same torque that is achievable in an inner turning rotor can be achieved in an outer turning rotor in either a smaller diameter or a shorter axial length. In  FIG. 4 , outer turning rotor  04230  is, as stated, of an induction motor. A stator  04220  is affixed to the stator shaft  04210  and external rotor  04230  is arranged to rotate about stator  04220  and stator shaft  04210 , which are fixed. 
         [0182]      FIG. 5  is an enlargement of the portion B-B of the electric motor of  FIG. 4 . Here it is seen that the external rotor  04230  is rotatably supported on stator shaft  04210  by bearings  04231  and  04232  (only partially shown in  FIG. 5 ), which in this specific illustrative embodiment of the invention are conventional ball bearings. 
         [0183]      FIG. 6  is a simplified schematic transaxial cross-sectional representation of a portion of stator  04220  of outer rotor induction motor  04200  (not shown in this figure). The represented portion of stator  04220 , in some embodiments of the invention, corresponds to a ferromagnetic lamination element  04221  of stator  04220  (designated generally in this figure). In this specific illustrative embodiment of the invention, stator  04220  is configured to have twenty-four slots (each of which is individually numbered in the figure). 
         [0184]      FIG. 7  is an enlargement of a fragmented portion of stator  04220  of  FIG. 6 . This figure shows two of the twenty-four slots in greater detail. As shown in this figure, representative slots  07224  and  07225  each extend substantially radially through stator  04220 , and have a substantially V-shaped configuration. Each such slot has, in this specific illustrative embodiment of the invention, substantially inward portions  07226  that reduce the circumferential dimension of the slot opening and thereby enhance the security with which the stator windings (not shown) are retained within the slots. 
         [0185]      FIG. 8  is a simplified schematic cross-sectional representation of rotor  04230  of the outer rotor induction motor embodiment of the present invention having thirty-two substantially round-shaped slots  08235 . 
         [0186]      FIG. 9  is an enlargement of a portion of the rotor embodiment of  FIG. 8  showing one of the thirty-two substantially round-shaped slots in greater detail. 
         [0187]    The rotor comprises 32 round shaped slots, as shown in  FIGS. 8 and 9 . The use of 32 bars ensures that there are no dangerous parasitic synchronous locking torques. The lowest common harmonic orders of the magneto-motive force between the stator with 24 magnetic teeth, as described above, and the rotor with 32 magnetic teeth, when there are two magnetic poles, is 95 and 97. This will create a minor torque dip at zero rotational speed. Hence, the outer rotor of the present application does not need to be skewed to eliminate the parasitic synchronous torques. Simple cross-sectional shapes, such as circular or square, for the bars will be adequate. 
         [0188]      FIG. 10  shows conductive rotor bars  10236 , which in some embodiments of the invention are made of aluminum, and are, in this embodiment, inserted directly in the rotor slots  08235 , as herein illustrated. Short-circuit elements short circuit respective ends of the rotor conductors. 
         [0189]      FIG. 11  is a simplified schematic representation of a winding distribution useful in the practice of the present invention. The 2-pole winding can be inserted automatically in a one layer distribution as shown in this figure. By way of example, in this specific illustrative embodiment of the invention winding a wire portion  11224  loops between slots numbered  1  and  14 . Similarly, wire portion  11225  loops between slots numbered  23  and  12 , wire portion  11226  loops between slots numbered  13  and  2 , and wire portion  11227  loops between slots numbered  11  and  24 . 
         [0190]      FIG. 12  is a simplified flux diagram that illustrates the tight linkage between the stator and rotor under load conditions that is achieved by a specific illustrative embodiment of the invention. This figure illustrates the tight linkage between the stator and rotor under load conditions. It is seen from this figure that the highest flux-density occurs in the rotor back iron. 
         [0191]    Since the rotor is located outside of the stator, the rotor diameter at the area facing the stator is larger than for an inner rotor configuration. The torque of a motor is proportional to the volume in the motor air-gap (L*n*D 2 /4) where L is the active stack length and D is the rotor diameter. Because the diameter D is larger than that of an internal rotor induction motor, a reduced value for the stack length L is achievable for a given torque. An illustrative embodiment of the outer rotor induction motor of the present invention has a ratio D/L of 0.7. By comparison with the inner rotor induction motor configuration, the outer rotor solution has a higher (torque):(total volume) ratio. 
         [0192]    The main loss component in a motor is the stator winding copper loss. The primary way of dissipating heat from the stator to the ambient environment in a conventional motorized drum having a closed thermal system is by means of conducting the motor heat to oil that in turn conducts the motor heat to the drum shell. The heat in the drum shell can then be conducted to the conveyor belt, if one exists, or convected to the ambient air, if no belt is present. 
         [0193]    However, it is a significant feature of the present invention that oil is not used. Instead, a gas flow loop  18249  (see,  FIG. 18 ), which in some embodiments is an air flow loop, is generated by use of a one or more axial air impellers having, for example, rotary fins. In the embodiment of  FIG. 18 , a centrifugal rotary fin  18240  is attached to the primary rotor end lid  18233 . This fan impeller fin, like the outer turning rotor, has a larger diameter than if it were attached to an inner turning rotor, and accordingly has greater effective gas flow. The gas flow loop has an axial toroidal flow path between the rotor and the stator and another toroidal axial flow path in the opposite direction between the rotor and the inner surface of the drum shell, which is substantially impermeable. The secondary rotor end lid  18234  is simply spoked to have minimal effect on the gas flow loop generated by centrifugal rotary fins  18240 . 
         [0194]    In other embodiments that are not herein shown, axial fin designs are embedded into the primary and secondary rotor end lids to generate the gas flow. 
         [0195]    An outer turning rotor significantly reduces the likelihood of catastrophic motor failure that would result from deflection and misalignment inherent in conventional motorized drums. In the present invention, as shown in  FIG. 3 , fixed stator shaft  03210  of motor  03200  serves as the fixed central shaft  03210  of motorized drum  03000  mounted to drum shell  03700  by means of base unit bearings  03710  and  03711 . In this construction, during operation, the only significantly deflecting part is fixed central shaft  03210 . Stator  03220  is directly affixed to central shaft  03210  and outer turning rotor  03230  is affixed to the fixed central shaft by rotor bearing  03231  in the primary rotor end lid  03233  and by rotor bearing  03232  in secondary rotor end lid  03234 . Therefore, stator  03220  and outer turning rotor  03230  move in tandem as the fixed central shaft  03210  deflects. 
         [0196]      FIGS. 13-17  relate to an embodiment of the present invention wherein the outer turning rotor is of a permanent magnet motor.  FIG. 13  is a cross-sectional representation of the outer turning permanent magnet motor  03200 . In this illustrative embodiment, magnets are embedded in magnet receiving slots between inner and outer circumferential peripheral surfaces of a ferromagnetic rotor element, such as a rotor  03230 , in polarity pairs of north magnets  13244  and south magnets  13243 . The rotor rotates around stator  03220 . The magnets are arranged so that every other magnet has an opposite polarity, thus forming an alternating pattern of north paired magnets  13244  and south paired magnets  13243 . The magnets shown are rectangular with a magnet face intermediate of two corners. Further, the magnet pairs are arranged so that the adjacent polarity corners are radially outward of the distal same-polarity corners. In this fashion, the magnetic flux is focused by the angled pairs of magnets and therefore causes a feedback in the stator  03220  that is sensed by the controlling power electronics (not shown) to determine the position of rotor  03230  relative to stator  03220 . One advantage of this design is that no additional physical encoders or sensors are required to be inserted into motorized drum  03000  for the controlling power electronics to drive motor  03200  properly. 
         [0197]    Further, in this illustrative embodiment, rotor  03230  does not utilize a housing. Instead, rotor lamination  03241 , shown in  FIG. 13   b , utilizes a circumferential gap or hole  13246  between the same polarity magnet pairs through which the lamination stack is fastened between both rotor end lids by means of rotor lamination clamp bolt  03242  ( FIG. 3 ). This design minimizes the overall diameter of motor  03200 , enabling achievement of greater torque density. 
         [0198]      FIGS. 14   a  and  14   b  further illustrate the magnetic flux circuit through the rotor laminations pattern that is created with this illustrative embodiment. 
         [0199]      FIGS. 15 ,  16 , and  17  illustrate another embodiment of the permanent magnet motor. In this embodiment, the magnets are not embedded into the outer turning rotor, but rather the magnets  15245  are surface mounted to the interior periphery (not specifically designated) of the rotor housing. In this embodiment, the magnets are configured in a spiral, which reduces cogging torque. However, in other embodiments, the spiral, or helical, configuration is not required and the magnets are surface mounted axially along the inner periphery of the rotor housing, with an adhesive, for example. 
         [0200]      FIG. 19  is a cross-section representation through a conventional cycloidal speed reducer  19100 , which is commonly mounted to a standard external motor by bolting the face (not specifically designated) of the cycloidal reducer housing to the external motor (not shown in this figure). In this representation of prior art, cycloidal reducer housing  19160  functions as the fixed reference point of the reducer. Around the inner periphery of the cycloidal reducer housing  19160 , ring pins  19161  are inset. In some low reduction ratios, the ring pins  19161  are encased by ring pin bushings  19162 , which, in turn, function as the internal-toothed ring gear that engages the external toothed gear or cycloidal disk  19140 . In other higher reduction ratios, not shown, the ring pins are inset in the housing without bushings and engage the cycloidal disk directly. 
         [0201]    Eccentric input shaft  19111  rotates and urges the cycloidal disk  19140  to oscillate about the ring pin bushings  19162  of the internal-toothed ring gear. In  FIG. 19 , there are twelve ring pin bushings  19162 , or internal gear teeth, about the inner circumference of the cycloidal reducer housing  19160  and there are eleven lobes, or external gear teeth, about the outer circumference of the cycloidal disk  19140 . Each full revolution of the eccentric input shaft  19111  causes the lobes of the cycloidal disk  19140  to engage each subsequent ring pin bushing  19162 . Therefore, in this illustrative embodiment, because the cycloidal disk  19140  has eleven lobes and there are twelve ring pin bushings  19162 , the cycloidal disk  19140  has engaged only eleven of the twelve ring pin bushings  19162 , effectively causing the cycloidal disk  19140  to rotate backward one ring pin bushing. Generally, a cycloidal disk has n external teeth engaging at least n+1internal teeth in the ring gear. As the cycloidal disk  19140  rotates, apertures  19141  in the cycloidal disk  19140  engage guide pins  19152  and guide pin bushings  19153 , causing the guide pins  19152  and bushings  19153  to rotate with the cycloidal disk  19140 . These guide pins  19152  and bushings  19153  are affixed to a guide pin support ring (not shown), which functions as the output of the reducer. 
         [0202]    This concept is clearly employed in the conventional drum motor of  FIG. 2 , where the face of cycloidal reducer housing  19160  (labeled  2020  in  FIG. 2 ) is bolted to a conventional motor. An output shaft  2030  of  FIG. 2  is rigidly connected internally to the guide pins  19152  and guide pin bushings  19153  of  FIG. 19 . 
         [0203]      FIG. 20  is a cross-section through a cycloidal speed reducer of the present invention  20100 , which is mounted within a motorized drum (not shown in this figure). Unlike the prior art where the face of the cycloidal reducer housing is bolted to the motor, in this illustrative embodiment, cycloidal reducer housing  20160 , which is the internal ring gear, is mounted directly to the inner periphery of the drum shell  03700 . Therefore, cycloidal reducer housing  20160  does not serve as the fixed reference point of the reducer, but instead serves as the output of the reducer, rotating synchronously with the drum shell  03700 . 
         [0204]    In the embodiment of  FIG. 20 , there are shown twenty ring pins  20161  and twenty ring pin bushings  20162  about the inner circumference of the cycloidal housing  20160 , which function as the inner ring gear. There are nineteen lobes about the outer circumference of the cycloidal disk  20140 . In this embodiment, the guide pins  20152  and guide pin bushings  20153  are affixed to a guide pin support ring  03150 , also referred to as a guide pin housing, (not shown in  FIG. 20 ) that is coupled to the central fixed shaft  03210  (not shown in  FIG. 20 ) by means of a high torque coupler  03350  (not shown in  FIG. 20 ) in order to function as the fixed reference point of the cycloidal reducer  20100 . As the eccentric input shaft  20110  rotates, the apertures  20141  in the cycloidal disk  20140  engage guide pins  20152  and guide pin bushings  20153 , the cycloidal disk oscillates around the guide pins  20152  and guide pin bushings  20153 . This oscillation movement of cycloidal disk  20140  engages each subsequent ring pin bushing  20162 . Since there are more ring pin bushings  20162  than lobes on the cycloidal disk  20140 , the internal ring gear of the cycloidal housing  20160  is advanced one ring pin bushing  20153  for every full rotation of the eccentric input shaft  20110 . Thus the internal ring gear rotates at a reduced rate relative top the input shaft. 
         [0205]    In the preferred illustrative embodiment of  FIG. 20 , eccentric input shaft  20110  of the cycloidal reducer  20100  is tubular with a hollow bore, thereby enabling the stator winding leads  03223  (not shown in  FIG. 20 ) and the central shaft  03210  (not shown in  FIG. 20 ) of the motorized drum  03000  (not shown in  FIG. 20 ) to pass through the center of the cycloidal reducer  20100 .  FIG. 3  of the same preferred embodiment shows the stator winding leads  03223  and the central shaft  03210  passing through the hollow bore eccentric input shaft  03110  of the cycloidal reducer  03100 . An advantage of this design is that the cycloidal reducer  03100  is mounted to the drum shell  03700 , which is the most rigid element of the motorized drum  03000 . There is sufficient clearance between the hollow bore input shaft  20110  and the central shaft  03210  so that when the central shaft deflects, it has no impact upon the cycloidal reducer  03100  because it has no contact with the hollow bore eccentric input shaft  20110 . 
         [0206]    A further advantage of the preferred embodiment of  FIGS. 3 and 20  is that the heat generated from the rolling action of the cycloidal reducer elements is conducted immediately to the drum shell  03700  by means of the direct contact of the cycloidal reducer housing  20160 ,  03160  to the drum shell  03700 . 
         [0207]    By engaging the cycloidal housing  20160  directly to the drum shell  03700 , a larger cycloidal reducer  20100  can be used within a given drum shell diameter, thus enabling a greater torque density of the motorized drum  03000  for a given axial length. As cycloidal reducers are inherently axially compact, the torque density is maximized for both the axial length and available internal diameter of the drum shell. 
         [0208]    In some embodiments where high speed reductions are required, another embodiment of a high torque reducer is harmonic speed reducer  21800  shown in  FIG. 21 .  FIG. 21  is a simplified schematic representation of a motorized drum  21000  that utilizes a harmonic speed reducer  21800  with a hollow bore input, wherein the major axis of wave generator  21810  is in the horizontal position. Harmonic speed reducer  21800  operates using the same basic principles as a cycloidal reducer, in that the rigid circular spline  21830  has more teeth than the flexible spline member  21820  being driven by the wave generator  21810 . Every revolution of the wave generator  21810  effectively causes the rigid circular spline  21830  to advance by the amount of teeth that exceed the number of teeth of the flexible spline member  21820 . 
         [0209]    In this embodiment, rigid circular spline  21830  is mounted directly to drum shell  03700  and functions as the output of harmonic speed reducer  21800 . Flexible spline  21820  is affixed to the central shaft by means of an affixing pin  21831  and functions as the fixed reference point of the harmonic speed reducer  21800 . Wave generator  21810 , which is the input of harmonic speed reducer  21800 , is hollow so as to allow stator lead wires  03223  and central shaft  03210  to pass through the center of harmonic speed reducer  21800 . 
         [0210]      FIG. 22  is shows the same harmonic speed reducer of  FIG. 21 , wherein the major axis of the wave generator is in the vertical position. 
         [0211]      FIGS. 23 and 24  are simplified isometric representations of the hollow bore input  03110  of the cycloidal reducer of the present invention. It is of a substantially tubular configuration utilizing protuberances referred to as protruding tabs  23130  to receive the motor input and utilizing integral eccentric raceways  23120  to engage the cycloidal disk input gears (not shown). In this illustrative embodiment, the input shaft of the cycloidal reducer is hollow, enabling the central shaft and stator winding leads to pass through the center of the cycloidal reducer. 
         [0212]      FIG. 25  is a simplified partially exploded isometric schematic representation that is useful to illustrate the power transmission coupling arrangement between the outer rotor of an electric motor, a cycloidal speed reducer, and a central shaft of an embodiment of the invention. This figure demonstrates how the present invention accommodates the misalignment and deflection inherent in all motorized drums in an axially compact manner. 
         [0213]    Central shaft  03210  of the motor  03200  extends throughout motorized drum  03000  (not specifically designated in this figure), specifically extending through the center of the hollow bore eccentric input shaft  20110  of the cycloidal reducer. In this preferred illustrative embodiment, the angular and concentric misalignments between motor  03200  and eccentric input shaft  20110  of cycloidal reducer caused by the deflection of central shaft  03210 , are accommodated by a high speed coupler  03310 . 
         [0214]    The protruding rotor tabs  03247  engage the slots on the outer circumference of the axially narrow high speed coupler  03310 . Additionally, protruding tabs  23130  of hollow bore eccentric input shaft  20110  of the cycloidal reducer engage slots in the inner circumference of high speed coupler  03310 . Proper clearance between the outer slots of the high speed coupler  03310  and rotor tabs  03247 , and proper clearance between the inner slots of high speed coupler  03310  and hollow bore eccentric input shaft tabs  23130 , as well as proper clearance between the outer diameter of central shaft  03210  and the inner diameter of high speed coupler  03310 , enable the coupler to angle and slide across the various driving faces. 
         [0215]    Guide pins  20152  and guide pin bushings  20153  around which cycloidal disks  20140  oscillate are affixed to primary guide pin support ring  03150 . Primary guide pin support ring  03150  has internal slots on the axial side of the primary guide support ring opposite motor  03200 . These internal slots receive the protruding tabs of high torque coupler  03350 . High torque coupler  03350  has keyways on the inner circumference and is affixed to the central shaft by shaft keys  03351 . In this way, the fixed reference point of the cycloidal reducer is effectively connected to central shaft  03210 . 
         [0216]      FIG. 26   a  is a simplified schematic representation of motorized drum  03000 , having a coupler arrangement (not shown in this figure) constructed in accordance with the invention.  FIG. 26   b  is a plan cross-sectional representation of a shaft coupler  03350 , and  FIG. 26   c  is an end view of motorized drum  03000 . These figures show motorized drum  03000  to have a drum shell  03700  arranged to be rotatable about the central motor shaft  03210 . The drum shell is sealed on the left-hand side of  FIG. 26   a  to central motor shaft  03210  by an end lid  03410 . 
         [0217]      FIG. 27  is a simplified cross-sectional representation of the embodiment of  FIG. 25  taken along section A-A of  FIG. 25   a  and showing the coupling between the motor, the reducer and the shaft. As shown in this figure, an electric motor  03200  is coupled by means of high speed coupler  03310  noted above that is coupled to the cycloidal reducer input  27110 . In this specific illustrative embodiment of the invention, the cycloidal reducer fixed reference  27150  is connected to central motor shaft  03210  by high torque coupler  03350 . Drum shell  03700  is urged into rotation by virtue of its connection to the cyclo drive output  27160 . High torque coupler  03350  prevents rotatory motion of cycloidal reducer fixed reference  27150  relative to central motor shaft  03210 , while simultaneously accommodating for misalignment of central shaft  03210  relative to the cycloidal reducer fixed reference  27150  when the central shaft  03210  is flexed under load. High speed coupler  03310  also accommodates for misalignment between motor  03200  and the cycloidal input  27110  that results from the flexing of central motor shaft  03210 . In this cross-sectional representation, rotor tabs  03247  are not seen because one is outside the surface of the figure and the other is behind the central motor shaft. 
         [0218]      FIG. 28  is a simplified schematic representation of the coupling between rotor  03230  of electric motor  03200 , cycloidal reducer  03100 , and central shaft  03210  of an embodiment of the invention. 
         [0219]      FIG. 29  is a simplified partially exploded isometric representation of the coupling system between rotor  03230  of electric motor  03200 , cycloidal reducer  03100 , and central motor shaft  03210 . 
         [0220]      FIG. 30  is another simplified partially exploded isometric representation, viewed from a second angle, of the coupling system between rotor  03230  of electric motor  03200 , cycloidal reducer  03100 , and central motor shaft  03210 . Elements of structure that have previously been discussed are similarly designated. As shown in these figures, the high speed coupler is configured to have two radially outward slots about the outer circumference to receive rotor tabs  03247  of motor  03230 , and two radially inward slots about the inner circumference to receive the protruding tabs of cycloidal reducer input  27110 . The slots or notches of the high speed coupler function as key ways and are arranged in substantially 90° displacement relative to each other. 
         [0221]    The high speed coupler has four active orthogonal driving faces at any point in time. In  FIG. 35 , which shows an illustrative embodiment, two of the active driving faces  35312 ,  35314  are parallel to each other and can be considered the first pair of the orthogonal driving faces; and the other two active driving faces  35316 ,  35318  are parallel to each other and can be considered the second pair of orthogonal driving faces. In this illustrative arrangement, the first pair of active drive faces is orthogonal to the second pair of active drive faces. 
         [0222]    Two orthogonal driving faces  35312 ,  35314  actively receive torque from two respective orthogonal driving faces  35311 ,  35313  from the rotor tabs, which can be considered drive elements. 
         [0223]    Two orthogonal driving faces  35318 ,  35316  transmit torque to two respective orthogonal driving faces  35317 ,  35315  of cycloidal reducer input  27110 , which can be considered to have a pair of driven elements. Therefore, a total of eight orthogonal driving faces are constantly engaged during operation. 
         [0224]    A variety of orthogonal arrangements are possible.  FIG. 31  is a simplified schematic isometric representation that shows a high speed coupler  31310  with protruding tabs about the outer circumference to receive slots from the outer turning rotor, and protruding tabs about the inner circumference to receive slots in the hollow bore eccentric cycloidal reducer input shaft. 
         [0225]      FIG. 32  is a simplified schematic isometric representation that shows slots about the inner circumference of high speed coupler  32310  to receive the rotor tabs, and protruding tabs about the inner circumference of high speed coupler  32310  to receive the slots of the hollow bore eccentric input shaft of the cycloidal reducer. 
         [0226]      FIG. 33  is a simplified schematic isometric representation that further shows two slots about the inner circumference of high speed coupler, also referred to as an engagement coupler or speed coupler,  33319  to receive the rotor tabs, and one protruding tab about the inner circumference and one slot about the inner circumference in order to receive a corresponding slot and tab from the hollow bore eccentric input shaft of the cycloidal reducer. 
         [0227]      FIG. 34  is a simplified schematic isometric representation that shows high speed coupler  34310  of this illustrative embodiment more clearly by eliminating the central shaft from the drawing. An advantage of this high speed coupling is that angular and concentric misalignment between the rotor and the input of the cycloidal reducer is accommodated, yet uninterrupted torque is delivered to the cycloidal reducer. 
         [0228]    As noted, the cycloidal fixed reference  27150  of  FIGS. 29-30  is fixed relative to central shaft  03210 , but is permitted to accommodate misalignment resulting from the flexing of the central shaft when the system is under lateral load. This accommodation is achieved by a reference coupler arrangement in which a high torque coupler, also referred to as an engagement coupler or reference coupler,  03350  is rotationally fixed to central shaft  03210  by engagement with a radial shaft key  03351  that engages a corresponding keyway that extends longitudinally within high torque coupler  03350 . High torque coupler  03350  is circumferentially configured with protruding tabs to fit within a corresponding slot in the fixed reference of the cycloidal reducer. Therefore, the same concept of orthogonal driving faces employed with the high speed coupler of  FIG. 35  is employed, as well, by the high torque coupler. 
         [0229]      FIG. 35  is another simplified schematic representation of an illustrative embodiment of the means by which the high torque coupler is affixed to the shaft. Rather than using keyways with matching keys, a keyless bushing  35352  is used. The advantage of a keyless bushing is that a smaller diameter central shaft can be used in the practice of the invention. 
         [0230]      FIG. 36  is a simplified axial cross-sectional representation of a motorized drum  36000  of an embodiment of the present invention, wherein an extension shaft  36560  is mounted to mounting face  36512  of base unit  03010  (denoted in  FIG. 3 ). Extension shaft  36560  is rigidly connected to clamp ring  36530  that is affixed against mounting face  03512  by use of a plurality of fasteners (extension clamping bolts  36532 ) extending through clamp ring  36530  and threading into mounting ring  03510  on the opposite side of mounting face  03512 . The mounting ring is located some distance from the determined region of rotary power delivery or where the reducer delivers power to the drum shell. 
         [0231]    Axially inward of mounting face  03512  is mounting ring  03510 . The mounting ring  03510  has a chamfer on the outer circumference of its axially outward face. The chamfer of mounting ring  03510  is in direct contact with spring ring  03511 . The spring ring, which may be formed of a hardened metal with an aggressive texture, may have a cross-sectional geometry that is generally circular or diamond or rectangular, for example. Spring ring  03511 , mounting ring  03510 , and mounting face  03512  are held in place by means of mounting ring alignment bolts  36513  when an attachable component is not mounted to mounting face  03512 . In this illustrative embodiment, extension clamping bolts  36532  are used to draw clamp ring  36530  toward mounting ring  03510  thus causing the chamfer on mounting ring  03510  to be drawn against spring ring  03511 , forcing the spring ring to expand radially into drum shell  03700 , thereby transmitting the transaxial forces of extension shaft  36560  into drum shell  03700 . 
         [0232]      FIG. 37  is a simplified axial cross-sectional representation of a motorized drum  37000  of a further embodiment of the present invention, wherein clamp ring  37530  of extension shaft  37560  directly contacts with mounting ring  37510  of base unit  03010  (denoted in  FIG. 3 ), without the use of an intervening mounting face. In this embodiment, mounting ring  37510  has a similar chamfer as in  FIG. 36  and is drawn similarly against spring ring  37511  by use of fasteners extending through clamp ring  37530 . 
         [0233]      FIG. 38  is a simplified axial cross-sectional representation of a motorized drum of a particular embodiment of the present invention, wherein an extension shell attachment  03560  (denoted in  FIG. 3 ) is attached to mounting face  03510  of base unit  03010  (denoted in  FIG. 3 ) and held in place by means of a large central nut  38551 . Before mounting extension shell attachment  03560 , threaded flange  38550  is mounted to mounting face  03512  by use of a plurality of fasteners (not shown) that thread into mounting ring  03510 , thereby drawing the chamfer of mounting ring  03510  against spring ring  03511  such that spring ring  03511  expands radially into drum shell  03700 . Additionally, clamp ring  03530  is inserted into extension shell attachment  03560  and a secondary spring ring  03531  is inserted into a circumferential groove in the inner periphery of extension shell attachment  03560  axially outward of clamp ring  03530 . Then, extension shell attachment  03560  is placed against base unit  03010  and a central nut  38551  is inserted from opposite end of shell extension attachment  03560 . This central nut  38551  is treaded onto threaded flange  38550 , thereby drawing clamp ring  03531  against secondary spring ring  03531  causing secondary spring ring  03531  to expand radially into extension shell attachment  03560 . 
         [0234]      FIG. 39  is an isometric exploded view of the mounting face system utilized in attaching extension shell component  03560  to base unit  03010  of a motorized drum  03000 , as an embodiment of the present invention. In this embodiment, rather than using one central nut, a plurality of extension clamping bolts  03532  are used with mating cam faced washers  03533 . The same principles demonstrated in  FIG. 38  are shown in  FIG. 39 . Additionally, a bolt holder  03534  aids in mounting of extension shell attachment  03560  by assuring the extension clamping bolts  03532  remain in clamp ring  03530  during installation, while accommodating for the extra distance required by extension clamping bolts  03532  that are not yet threaded into mounting ring  03510 . 
         [0235]    The end lid is connected to the motorized drum by means of an embossed spring band.  FIG. 40  is a simplified representation of an embossed spring band  03420 , also known as a tolerance ring. 
         [0236]      FIG. 41  is an isometric cut-away of one embodiment of embossed spring band  03571  that holds end lid  03570  against the motorized drum in a drum shell closure arrangement of the present invention. The embossed spring band  03571  is disposed between two concentric protuberances, also referred to as cylindrical geometries, of end lid  03570  and mounting face  03512  and when the two concentric protuberances are nested together in an end lid assembly, embossed spring band  03571  is compressed creating an interference fit between the two concentric protuberances. The mating concentric protuberances of the end lid and the mounting face have different nominal diameters. 
         [0237]    In another illustrative embodiment, a static polymeric seal is disposed between the end lid and the drum shell.  FIG. 42(   a ) is a simplified cross-sectional representation of such an embodiment. A polymeric seal  03572  is enclosed between end lid  03570  and drum shell  03700 . A ring compression geometry is about the outer circumference of the axial inward face of end lid  03570 . When end lid  03570  is held in place by the embossed spring ring, the ring compression geometry imposes a compressive force on seal  03572 . 
         [0238]    In another embodiment, not shown in figure, the ring compression geometry is on an axially outward face of the drum shell about an outer circumference of the end lid. 
         [0239]      FIG. 42(   b ) is a simplified cross-sectional representation of an embodiment of the compression geometry utilized in the end lid where the end lid contacts the static drum shell seal in the motorized drum of the present invention and the ring compression geometry utilized in the end lid where the end lid contacts the rotary seal, also referred to as radial seal, in response to the application of an installation force, the end lid remaining in fixed relation to the polymeric rotary seal by operation of an embossed spring band that is deformed upon installation. Examples of rotary seals include rotary lip seals, rotary shaft seals or polymeric rotary lip seals. The embodiment of  FIG. 42(   b ) bears similarity to that of  FIG. 42(   a ), and accordingly, elements of structure that have previously been discussed are similarly designated. 
         [0240]      FIG. 43  is a simplified cross-sectional representation of another illustrative embodiment wherein a compressive force is maintained against seal  03450  by designing end lid  03410  with a thin wall, also referred to as an annular web, in the radial distance between the embossed spring band and the outer diameter to create a spring-like effect resulting from the axially resilient characteristic of the annular web. In this embodiment, the central portion of the end lid is held axially inward by embossed spring band  03420  slightly farther than the natural contact point between the outer portion of end lid  03410  and outer static seal  03450  thereby maintaining a constant compressive force against static seal  03450 . 
         [0241]    Inasmuch as end lid  03570  covers mounting face  03512  on one side of motorized drum  03000 , and inasmuch as compressed embossed spring band  03571  requires three tons of force to remove it, end lid  03570  has been designed with a geometry that mates with a removal tool clamp for simple removal in the field.  FIG. 46  is a simplified isometric representation of one embodiment of the end lid removal tool as it is attached to the end lid of the motorized drum.  FIG. 47  is a simplified isometric exploded representation of the embodiment of  FIG. 46 . End lid  03410  has a recessed, outer circumferential geometry  46920 , also referred to as an end lid recess. Removal tool clamp  46940  has a recessed, inner circumferential geometry  46930 , also referred to as an tool recess, that corresponds to geometry  46920  of end lid  03410 . When removal tool clamp  46940  is placed over end lid  03410 , two recessed geometries  46920 ,  46930  form a circular channel. A joining cord  46910  of a slightly smaller diameter than the circular channel is inserted through a tangential hole, or inlet, in removal tool clamp  46940 . The inserted joining cord  46910  effectively locks end lid  03410  to removal tool clamp  46940 , which can now be easily removed with a force generating arrangement, such as slide hammer  46950 . 
         [0242]      FIG. 44  is a simplified cross-sectional representation of one embodiment of the compression geometry utilized in the end lid where the end lid contacts the rotary shaft seal of the motorized drum. A polymeric seal  03542  is placed directly against end lid  03570 . End lid  03570  has a ring compression geometry on its axial inward face about its outer circumference. A seal compression plate  03540  is attached to the end lid by a plurality of fasteners  03541 , compressing seal  03542  between seal compression plate  03540  and end lid  03570  to form an end lid seal assembly. A significant compressive force is applied at the ring compression geometry of end lid  03570  preventing ingress of bacteria between seal  03542  and end lid  03570 . 
         [0243]    In another embodiment, not shown in figure, the ring compression geometry is on a axially outward face of the seal compression plate about an inner circumference of the end lid. 
         [0244]      FIG. 45  is a simplified partially cross-sectional representation of an embodiment of the rotary shaft seal compression system of a motorized drum. 
         [0245]      FIG. 48  is a simplified schematic representation of a cleaning-in-place system for the rotary shaft seals of the motorized drum. The cleaning-in-place system includes: 
         [0246]    a shaft  48210  with first cleaning conduit  48610  and second cleaning conduit  48611 ; 
         [0247]    an inlet port  48620  attached to first cleaning conduit  48610 ; 
         [0248]    an outlet port  48621  attached to second cleaning conduit  48611 ; 
         [0249]    an end lid  48570 ; 
         [0250]    a first axially outward polymeric radial seal  48630 ; 
         [0251]    a second axially outward polymeric radial seal  48631 ; 
         [0252]    an annular chamber  48613  formed between first and second radial seals  48630 ,  48631 ; 
         [0253]    a seal compression plate  48540 ; 
         [0254]    a seal spacer ring  48541 ; and 
         [0255]    a plurality of fasteners. 
         [0256]    In this illustrative embodiment, seals  48630 ,  48631  are stacked between end lid  48570  and seal compression plate  48540  and separated by seal spacer ring  48541 , thus forming annular chamber  48613 . A plurality of fasteners draw seal compression plate  48540  axially toward end lid  48570 . In a preferred embodiment, end lid  48570  includes a ring compression geometry on its axial inward face about its inner circumference (not shown in  FIG. 48 ), which imposes a compressive force against radial seal  48630 . In another embodiment (also not shown in  FIG. 48 ) a ring compression geometry is on an axial outward face of the seal spacer ring about an inner circumference of the end lid. 
         [0257]    Cleaning agents are delivered through inlet port  48620  into first cleaning conduit  48610  and into annular chamber  48613  and exit second cleaning conduit  48611  and outlet port  48621 . When desired, outlet port  48621  can be used to restrict the flow, thus building greater pressure in annular chamber  48613 . When this pressure increases sufficiently, polymeric seal  48630  will be deflected outward and up and the cleaning fluid will pass between the radial face of seal  48630  and the surface of shaft  48210 . 
         [0258]      FIG. 48  further has a fluid conduit  48612  and a fluid port  48622  wherein fluid can be inserted or removed from drum chamber  48615 , which is a sealed region. 
         [0259]      FIG. 49  is a schematic of a seal monitoring system incorporating a conveyor component known as a drum motor. The seal monitoring system is comprised, in this embodiment, of a sealed drum chamber  48615 , from which proceeds a fluid line  49100  in which, there is a sensor  49200  to measure pressure that reports to controller  49300 . Subsequent to said sensor  49200  is a valve  49400  subsequently connected to pump  49500 . Both the valve  49400  and pump  49500  may be controlled by the controller  49300 . Pump  49500  may be capable of adding or subtracting fluids, particularly gases, to or from the drum chamber  48615 . Alternatively, the sensor  49200  could be incorporated in a manner other than shown to measure flow of the fluid in said fluid line  49100 . Additionally, the sensor  49200  could be mounted internal to the sealed drum chamber  48615  and may be attached to fluid line  49100  or it may be connected to the external environment in some other manner. 
         [0260]      FIG. 50  is an axial cross-section of a motorized drum of another particular embodiment of the present invention, wherein an extension shell attachment  50560  is attached to the mounting ring  50510 . In this embodiment, the drum shell  50700  is fitted with an internally beveled chamfer and the extension shell attachment  50560  is fitted with a mating externally beveled chamfer, referred to collectively as mating chamfers  50450 , by which the drum shell  50700  and the extension shell attachment  50560  are drawn together by a plurality of extension clamping bolts  50532  threading into the mounting ring  50510 . 
         [0261]    Axially inward of the mounting face  50512  is the mounting ring  50510 . The mounting ring  50510  has a groove on the periphery of the outer circumference of its axially outward face. This groove is in direct contact with the spring ring  50511 . 
         [0262]    Axially inward of the chamfered end of the extension shell attachment  50560  is a radially installed groove in which a spring ring  50531  is fitted. Axially inward of the spring ring  50531  is the clamp ring  50530 . The extension clamping bolts  50532  are used to draw the clamp ring  50530  toward the mounting ring  50510  thus causing the chamfer on the extension shell attachment  50560  to mate coaxially under compression with the chamfer on the drum shell  50700 , resulting in mating chamfers  50450 , thereby transmitting the transaxial forces of the extension shell attachment  50560  into the drum shell  50700 . 
         [0263]    In summary, the foregoing is directed in part to: 
         [0264]    eliminating the need for oil in the motor system, which poses a risk of cross contamination in sanitary applications; 
         [0265]    increasing the torque density of the motor within a fixed diameter and motor length; 
         [0266]    providing greater stability with variable loads; 
         [0267]    transmitting core stator heat to the drum shell through via a gas with the use of circumferential gas turbulence between the stator and the rotor and between the rotor and the drum shell where it can be removed by the belt; 
         [0268]    avoiding the need for additional position sensors to communicate the rotor position to the power electronics with the use of magnets, in some embodiments, that are embedded in the lamination stack and thereby cause a variation in magnetic flux around the circumference of the rotor, which variation can be detected by the power electronics that are connected to the stator windings; and 
         [0269]    accommodating the deflection caused through belt pull. 
         [0270]    Although the invention has been described in terms of specific embodiments and applications, persons skilled in the art can, in light of this teaching, generate additional embodiments without exceeding the scope, or departing from the spirit, of the invention described herein. Accordingly, it is to be understood that the drawing and description in this disclosure are proffered to facilitate comprehension of the invention, and should not be construed to limit the scope thereof.