Abstract:
A compact gear reducer electric motor assembly with an internal brake disclosed and claimed wherein a high speed electric motor is interconnected with a gear reducer having substantial gear reduction. The assembly includes a spindle, a brake mounted substantially within said high speed electric motor and operable against a spring biasing said brake into engagement with ground. The brake is electrically actuated to permit transmission of energy to the gear reducer. The gear reducer includes an input, intermediate and output planetary stages. The input and intermediate stages residing within the spindle, and, the output planetary stage drives an output ring gear. Releasing means for releasing the output ring gear from the brake allowing rotation thereof.

Description:
This patent application claims priority to provisional patent application Ser. No. 61/073,021 filed Jun. 16, 2008 and to provisional patent applications Ser. No. 61/097,456 filed Sep. 16, 2008. 
    
    
     FIELD OF THE INVENTION 
     The invention is in the field of torque hubs used to supply power and torque to drive wheels of vehicles. 
     BACKGROUND OF THE INVENTION 
     Small boom lifts, for example those less than 15,000 lbs. gross vehicle weight, are generally two wheel drive battery powered machines for indoor use only. The wheels on these machines are primarily driven with electric motors and planetary gearboxes on the non steering axle of the machine. The configuration of this electric drive system is extremely long and makes it impossible to drive the steering wheels because the electric motor extends too far and interferes with the operation of the vehicle by engaging the frame of the vehicle. In addition, because these electric motors are normally in the non-steer axle on an indoor machine, they do not have (or need) any sort of environmental protection. 
     The major hurdle for putting a hybrid electric system in a large gross vehicle weight machine, prior to the invention described and claimed herein, is that the same type of electric drive assembly used on small boom lifts cannot be used in large boom lifts. Therefore, there is a need for an electric drive assembly that has a higher power density and is environmentally protected. The instant invention solves the problem and answers the need. 
     SUMMARY OF THE INVENTION 
     The invention is an electric wheel drive assembly which includes a high speed electric motor, an internal brake and a three stage gear reducer. It can be used on aerial work platforms (boom lifts, large scissors lifts), tele-handlers, large fork lifts, agricultural vehicles and the like. The drive is powered with three phase electrical power to an induction AC motor. The front end of the motor shaft is supported by a bearing contained within an electromagnetic brake which is spring applied, electromagnetic release. The brake includes a friction disc which is connected (splined) to the motor shaft and provides parking and emergency braking. The motor shaft connects to the sun gear of a triple planetary gearbox with a gear reduction range of 90:1 to 160:1. The first two planetary stages are nested within the diameter of the main wheel support bearings. The output planetary stage resides toward the cover end and outputs to the ring gear which drives the wheel hub. The cover contains a cap secured with two screws that can be removed and then the cap may be flipped acting on rods  113  and  109  to disengage the assembly from the motor and brake. A rod pushes into the assembly against the force of a spring and disconnects a splined connection. 
     The invention provides advantages in the market in that an electric wheel drive may be used for a heavier machine. By way of example a boom lift type machine is described. However, the invention is not limited to this machine. Large boom lifts greater than 15,000 lbs. gross vehicle weight are generally suited for outdoor work and they can be two wheel drive or four wheel drive. Wheels on these machines are generally driven with hydraulic motors and planetary gearboxes. Hydraulic systems required to propel the wheels present a problem because the hydraulic system is typically driven by an internal combustion engine sized for the peak power and torque required out of the machine. Boom machines are very rarely operated at their peak power, for example, when climbing a steep grade (usually during loading on a trailer). Regardless of the output power required at the wheels or other systems, the hydraulic system constantly demands peak power out of the internal combustion engine, making it a very inefficient machine. With increasingly stringent emissions standards, consumers are considering a conversion of their boom lifts to machines employing hybrid electric systems. 
     A compact gear reducer electric motor assembly with an internal brake is disclosed and claimed wherein a high speed electric motor is interconnected with a gear reducer having substantial gear reduction. High power density is created by employing a high speed AC motor with a maximum speed of 6000 rotations per minute with a very compact high reduction gear box with a brake nested substantially within the windings of the motor. The assembly includes a spindle and a brake mounted substantially within the high speed electric motor. The brake is operable against a spring biasing said brake into engagement with a friction plate. The brake is electrically actuated which disengages the pressure plate from the friction plate or disc to permit rotation of the motor shaft and transmission of energy to the gear reducer. 
     The gear reducer includes input, intermediate and output planetary stages. The input and intermediate stages reside within the spindle and the output planetary stage drives an output ring gear. Releasing means for releasing the output ring gear from the brake allow rotation thereof such that the machine may be moved or towed. 
     The invention includes packaging the high speed planetary stages, for example the input and intermediate stages, within the main support bearings. Traditionally, the high speed gearing in a planetary wheel drive gearbox is towards the cover end. By housing the high speed stages within the bearings, three planetary stages are supported in a shorter axial length. 
     The invention, in one example, “nests” or houses the brake within the winding end turns of the electric motor. AC induction motors have long winding end turns that normally just occupy space. The invention utilizes this space as a place for the brake housing thus reducing the axial length of the motor-brake-gear reducer by approximately 1 inch. 
     The brake provides bearing support for the end of the motor shaft. A bearing is interposed between the motor shaft and the brake. The compact gear reducer electric motor assembly includes a high speed electric motor interconnected with a gear reducer having a gear reduction in the range of 1:90 to 1:160. The gear reducer includes a spindle and a disconnect shaft. The disconnect shaft transmits energy of the high speed electric motor to the gear reducer. An internal brake includes a housing and springs mounted therein and an electromagnetic coil therein. 
     The internal brake includes a friction plate affixed to the spindle. The internal brake further includes a housing and first and second pressure plates. The first and second pressure plates each include a passageway therethrough. A spacer resides between the first and second plates. The friction plate is affixed to the motor shaft and is rotatable therewith. The friction plate is generally disk-shaped having first and second sides and includes frictional material affixed thereto on the first and second sides thereof. 
     The springs of the brake are operable between the housing of the brake and the first pressure plate. The pressure plates are ferromagnetic and attractable by the coil of the brake when the coil is energized. The spring urges the first pressure plate into engagement with the friction plate when the coil is de-energized. The internal brake is substantially within the high speed electric motor. 
     The brake is electrically actuated to permit transmission of energy to the gear reducer. The gear reducer includes input, intermediate and output planetary stages. The input and intermediate stages reside within the spindle. The output planetary stage drives an output ring gear. The electric motor includes a shaft and the electric motor includes electric windings radially spaced from the shaft creating a void or space between the shaft and windings. The electric brake resides substantially within the space between the shaft and the windings. The input planetary stage includes an input planet sun gear and planet gears. The planet gears of the input stage have a first width and the intermediate planetary stage includes an intermediate sun gear and intermediate planet gears. The intermediate planet gears have a second width. The first width of the input stage gears is less than one-half the width of the intermediate planet gears having a second width. 
     Other examples employ different orientation of the brake assembly and different configurations of the planetary gear stages. 
     It is an object of the invention to provide a torque hub having a high speed electric motor, internal brake, and a gear reducer in a small volume. 
     It is a further object of the invention to provide a torque hub having a high speed electric motor which through a gearing reduction provides large torque for movement of the vehicle against a heavy load. 
     It is a further object of the invention to provide a torque hub which is relatively short as compared to a hydraulically driven motor enabling the vehicle to turn. 
     It is a further object of the invention to provide a torque hub which includes a brake substantially residing within an electric motor. 
     It is a further object of the invention to provide a torque hub which is short and compact. 
     It is a further object of the invention to provide a torque hub utilizing a gearbox wherein first and second stages thereof reside within the spindle and the third stage resides within an outer ring gear providing a quiet gear box with large speed reduction. 
     It is a further object of the invention to provide a torque hub which is short and compact and which employs sun planet gears which are less than one-half the width of the intermediate planet gears. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional assembly view of the preferred example of the motor-brake-gear reducer with the brake housing residing substantially within the electric motor. 
         FIG. 1A  is an enlargement of a portion of  FIG. 1  illustrating the input planet gears and intermediate planet gears. 
         FIG. 1B  is an enlargement of a portion of  FIG. 1  illustrating a portion of the brake. 
         FIG. 1C  is a perspective view of the assembly of the preferred example of the motor-brake-gear reducer. 
         FIG. 2  is a cross-sectional assembly view of another example of the motor-brake-gear reducer. 
         FIG. 2A  is an enlargement of a portion of  FIG. 2  illustrating the input planet gears and intermediate planet gears. 
         FIG. 3  is a cross-sectional assembly view of another example of the motor-brake-gear reducer. 
         FIG. 3A  is an enlargement of a portion of  FIG. 3  illustrating the input planet gears and intermediate planet gears. 
         FIG. 3B  is an outside perspective view of the example illustrated in  FIGS. 3 and 3A . 
         FIG. 4  is a cross-sectional assembly view of another example of the motor-brake-gear reducer. 
         FIG. 4A  is an enlargement of a portion of  FIG. 4  illustrating the input planet gears and intermediate planet gears. 
         FIG. 4B  is an outside perspective view of the example illustrated in  FIGS. 4 and 4A . 
     
    
    
     DESCRIPTION OF THE INVENTION 
       FIG. 1  is a cross-sectional assembly view  100  of the preferred example of the motor-brake-gear reducer with the brake housing residing substantially within the electric motor. Referring to  FIG. 1 , reference numeral  101 A is a steel spindle/input ring gear which houses the planetary gear stages. Lip seal  101 B seals the gap between the spindle/input ring gear and the wheel hub  101 D. Main bearings  101 C support the wheel hub  101 D and output ring gear  101 E for rotation relative to the spindle  101 A. Bearing nut  101 F and set screw  101 G secure the bearings  101 C in place longitudinally. Internal gears and gearbox components are made of steel or stainless steel. Spindle  101 A is steel or a steel alloy. 
       FIG. 1A  is an enlargement  100 A of a portion of  FIG. 1  illustrating the input planet gears  102 F and intermediate planet gears  103 F. Input carrier  102 A along with thrust plates  102 B are illustrated in  FIG. 1A . Input planet pins  102 E secure input planet gears  102 F to the input planet carrier  102 A. The input planet gears  102 F are secured by the input planet pin retaining rings  102 G. Input planet gears  102 F are driven  180  by input sun gear  110  which is driven by splined  172  disconnect shaft  109 . Retaining ring  112  retains the intermediate sun gear  116  and the input planet carrier  102 A. 
     Still referring to  FIG. 1A , input planet gears  102 F include 35 carburized teeth and are driven by carburized input sun gear  110  having 19 teeth. Input thrust plates  102 B secure input planet gears  102 F to the input planet pins  102 E. Input/intermediate planet bushings  103 C support input planet gears  102 F and intermediate planet gears  103 F. Input planet pin retaining rings  102 G secure thrust plates  102 B in place to retain input planet pins  102 E. Input sun gear  110  is trapped against longitudinal movement by motor shaft  141  and intermediate sun gear  116 . Similarly input thrust washers  103 B secure intermediate planet gears  103 F to the intermediate planet pins  103 E. Input carrier  102 A is driven by input planet pins  102 E and is splined  173  to intermediate sun gear  116 . Intermediate sun gear  116  includes 19 carburized teeth and drives  180  intermediate planet gears  103 F which interengage and react against teeth of internal ring gear  188  of spindle  101 A. 
     Intermediate sun retaining ring  112  retains input carrier  102 A. Thrust spacer  120  resides between input carrier  102 A and intermediate carrier  103 A. Intermediate carrier roll pin  103 G secures the intermediate carrier  103 A to the intermediate pin  103 E. The intermediate carrier  103 A serves to maintain and secure the thrust washers  103 B in place. A shoulder (unnumbered) on output sun gear  111  secures the intermediate carrier  103 A in place and hence the intermediate gears in place as well. See  FIG. 1 . Output carrier  104 A is splined  174 A to the internal ring gear  188  of the spindle  101 A and is stationary (fixed or is grounded). It should be noted that the input planet gears, the input carrier, the intermediate planet gears and the intermediate carrier are permitted to move longitudinally a small distance limited by retaining rings, thrust spacers and the other structure of the elements in proximity thereto. 
       FIG. 1B  is an enlargement of a portion of  FIG. 1  illustrating a portion  100 B of the brake  108 A. Inertia Dynamics Incorporated (hereinafter “IDI”) manufactures the spring applied-coil energized to release brake described herein. The IDI brake is adapted to be mounted to the spindle  101 A of the gear reducer in a direction opposite to the normal orientation so as to economically use the space  197  available within the spindle and the electric motor. The normal orientation of the brake can be viewed in  FIGS. 2-4 . Energized coil  130  in brake  108 A attracts ferromagnetic actuating plate  126  (sometimes referred to as the clapper) against the force of springs  164  and away from friction plate  125  to permit friction plate  125  to rotate with motor shaft  141 / 141 A. See  FIG. 1 . When coil  130  is actuated, plate  126  abuts body  108 A of the housing and gap  169  illustrated in  FIG. 1B  is eliminated. Coil  130  is a direct current coil operable at 80 Volts direct current, 27 Watts. 
     Friction plate  125  includes friction material  125 A affixed thereto. Adhesive is used to affix the friction material to the friction plate. The friction material is located near the circumferential extent of the friction plate  125 . When the brake is applied, springs  164  urge the actuating plate  126  against the friction plate  125  and, in particular, against the friction material  125 A affixed to the friction plate  125 . As illustrated in  FIG. 1B , the friction material  125 A is illustrated against and in engagement with plates  126  and  124 . Plate  124  is shown pinned  162  to the spindles  101 A as the spacer or standoff  161  is trapped between the body  108 A of the brake and the pressure plate  124 . Spacer or standoff  161  includes a passageway  163  therethrough for bolt  199 . Similarly, plate  126  includes a passageway  163 P for the spacer to reside. Pressure plate  124  includes a passageway  163 Q for bolt  199  to reside. Bolts  199  secure the housing  108 A to the spindle  101 A and prevent rotation of the plates  124 ,  126 . Bolt  199 , housing  108 A and spacer  161  secure plate  124  against and into engagement with spindle  101 A. Bolt  199  is illustrated forcing body  108 A against the spacer  161  which in turn forces the spacer against the pressure plate  124  which in turn forces the pressure plate  124  against the spindle  101 A. There are three bolts  199  and numerous springs  164  used in the assembly. Brake  108 A is sealed  108 C against the spindle  101 A. 
       FIG. 1C  is a perspective view  100 C of the assembly of the preferred example of the motor-brake-gear reducer illustrating the exterior of the motor  107 A (Advanced 72V alternating current motor, IP67 protection rating), spindle  101 A, the hub  101 D, and the exterior of the output ring gear  101 E. Motor  107 A is an Advanced 72 Volt alternating current motor carrying an IP  67  protection rating. IP stands for ingress protection and “6” is the highest rating for protection of dust infiltration and “7” is a rating for water infiltration when the enclosure is submersed 15 cm to 1 meter for 30 minutes. 
     Referring to  FIGS. 1 and 1C , motor  107 A has a generally cylindrically shaped tapered exterior. Motor shaft  141 / 141 A is an interference fit. Spring  140  bears upon disconnect shaft  109 . Towing of the machine is accomplished by reversing the orientation of the unnumbered cap which involves removal of the unnumbered screws. Once the orientation of the cap is reversed and is bolted in place, it forces an unnumbered rod leftwardly which forces rods  113  and  109  leftwardly. Once the disconnect cap is removed, the orientation of the cap is reversed such that the button portion of the cap is reversed (oriented leftwardly) pushing an unnumbered rod which acts upon disconnect rod  113  and disconnect shaft  109  moving them leftwardly causing disengagement of shaft  109  from the sun gear  110 . The bolts (unnumbered) are used to hold the button onto the cover  106 A. The reversely oriented button thus disconnects the motor from the gearbox putting it in the tow mode. Bushings  189  support internal disconnect rod  113 . Motor shaft  141 / 141 A is supported by bearings  142  at the generally leftward end of the motor and is supported by bearings  190  at the generally rightward end of the motor. Bearings reside between stationary brake  108 A and shaft  141 A. Brake  108 A is bolted with bolts  199  to spindle  101 A. Motor  107 A is sealed  107 C with O-rings to prevent the intrusion of water or dust at the joint of the spindle and motor. Motor  107 A is affixed to spindle  101 A with bolts which are unnumbered in  FIG. 1C . Motor  107 A is sealed such that the wires which supply power to the motor and the coil as well as wires which communicate with sensor  128  pass through the motor enclosure such that they are sealed from the intrusion of dust and water. 
     Brake  108 A is mounted in a direction such that the coil  130  protrudes into a cavity or volume  197  between the motor&#39;s windings  123  and the shaft of the motor  141 / 141 A. Brake  108 A resides in the diametrical bore  196  of one end of the spindle  101 A. Bearings  190  are tensioned and retained in place by spring  108 E operable between ring  108 D residing in a groove in an inner diametrical bore of the brake and the bearing  190 . Spring  108 E urges bearing  190  against a shoulder on the exterior of the shaft  141 A. Spindle  101 A forms intermediate ring gear  188 . 
     Referring to  FIG. 1A , input sun gear  110  is carburized and has 19 teeth. Input sun gear  110  is splined  172  to the disconnect shaft  109 . Input carrier  102 A is splined  173  to the intermediate sun  116  which in turn drives intermediate planet gears  103 F. Intermediate sun  116  and intermediate planet gears  103 F intermesh  181  with each other. It will be noticed that  FIGS. 1 and 1A  depict input planet gears  102 F which are less than one-half as wide as the intermediate planet gears  103 F which results in positioning the first and second planetary stages within ring gear  188  within the spindle  101 A thus saving axial space within the gearbox while effectively and efficiently transmitting power and torque. 
     Referring to  FIGS. 1 and 1A , input seal  108 F and brake O-ring  108 C seal the gearbox from the motor preventing unwanted lubricating oil in the motor. Hub  101 D is affixed to output ring gear  101 E with bolts  101 M. Main lip seal  101 B seals between the output ring gear  101 E, hub  101 D, and the spindle/input ring gear  101 A. Main bearings  101 C interengaging wheel hub  101 D and spindle  101 A enabling rotation of the wheel hub  101 D with respect to the spindle  101 A which is affixed to the vehicle and is not rotatable. Bearing nut  101 F and set screws  101 G ensure that bearings  101 C are secured against the spindle  101 A. Seals such as elastomeric O-ring seals  118  are used in the gearbox where necessary. 
     Still referring to  FIGS. 1 and 1A , intermediate gears  103 F drive intermediate carrier  103 A which is splined  174  to output sun gear  111 . The intermediate stage planet gears have 35 teeth. Carburized output sun gear  111  includes 25 teeth and drives  182  output planet gears  104 F which interengage teeth  188 A of the output ring gear  101 E. There are four output planet gears; however, different numbers of output planet gears may be used such as 3 or 5. Output carrier  104 A positions the output planet gears  104 F and output planet pins  104 E apart from the first (input stage) and the second (intermediate stage) and within the output ring gear  101 E. The number of teeth employed by the input planet gears, intermediate planet gears, and output planet gears are by way of example only as the invention includes the flexibility to employ different ratios by changing tooth combinations in the input and intermediate stages. 
     Still referring to  FIGS. 1 and 1A , the output planet carrier  104 A is stationary. Spline  174 A of the output planet carrier is interconnected with the internal ring gear  188  of the spindle. Therefore, the output carrier  104 A is stationary. Output planet pins  104 E are fixed within the output planet carrier  104 A. Output planet gears  104 F rotate about stationary output planet pins  104 E and intermesh  188 A with the output internal ring gear causing it to rotate and drive a wheel (not shown) affixed by studs  101 M and nuts (not shown). Output planet thrust washers  104 B abut the output carrier  104 A and prevent side to side movement of the output planet gears  104 F. Output planet needle rollers  104 C are separated by an output planet spacer  104 D and enable rotation of the output gears  104 F with respect to output planet pins  104 E. Output planet roll pins  104 G secure the output planet pins  104 E to the output planet carrier  104 A. 
     A double walled intermediate carrier  103 A is splined to the output sun gear  111 . Intermediate planet thrust washers  103 B secure the intermediate planet gears  103 F longitudinally and bushings  103 C are interposed between the input planet gears and the input planet pins  102 E. Bushings  103 C are interposed between the intermediate planet gears  103 F and the intermediate planet pins  103 E. Intermediate carrier roll pin  103 G secures the intermediate carrier  103 A to the intermediate planet pins to be driven by the planet gears. A thrust spacer  120  is located between the input and intermediate carriers. See  FIG. 1A . 
     Still referring to  FIGS. 1 and 1A , planet output carrier  104 A is secured with pins  104 G to the planet output pins  104 E. Output planet thrust washers  104 B secures the output planet gears  104 F against longitudinal movement. Output planet spacer  104 D separates the output planet needle roller bearings which are interposed between the interior of the output planet gears  104 F and the output pins  104 E to enable rotation of the output gears with respect to the output pins. Cover assembly  106 A is retained by the cover retaining ring  106 G. Cover thrust washer  106 B interengages output sun gear  111  driven by the intermediate carrier  103 A. 
     An Advanced 72V AC electric motor  107 A has an IP67 Protection Rating (waterproof to 1 meter) and drives splined disconnect shaft  109  which in turn drives the input sun gear  110  which in turn drives the input planet gears  102 F. The motor housing  107 A is, of course, affixed to the spindle  101 A as illustrated in  FIG. 1C . 
     Still referring to  FIG. 1 , an O-ring seal  107 C is interposed between the motor housing  107 A and spindle  101 A. An electric brake  108 A is affixed to the spindle  101 A with brake mounting bolts  199  and a seal  108 C resides between the brake and the spindle  101 A. The brake assembly includes a pressure plate  124 , a stationary plate  126 , and a friction plate  125 . Friction plate  125  is affixed to (splined  178 ) the motor shaft  141 / 141 A and rotates with the electric motor shaft  141 / 141 A. When the coil  130  in the housing  108 A is energized, the pressure plate  124  is pulled away from and disengages the friction plate  125  thus negating the brake. Springs  164  force the pressure plate  126  into engagement with the friction plate  125  which prohibits rotation of shaft  141 / 141 A. Bearing pre-load spring  108 E acts upon snap ring  108 D which resides in a recess in the inner bore of the brake  108 A. Motor sensor  128  is illustrated for use in connection with the speed control of the motor. A water seal  129  for the electrical wires (unnumbered) is also illustrated. The brake housing  108 A is mounted within the coil windings  123  of the electric motor. In this way space is saved and the overall length of the motor-gearbox-assembly is minimized. 
     The input planet gears  102 F are not as wide as the intermediate planet gears  103 F. The gear arrangement set forth in the preferred example as set forth in  FIGS. 1 ,  1 A and  1 B is superior to other arrangements because it is short in length, has high reduction, and is relatively impervious to dust and water. 
     The machine described herein includes a hybrid system containing a generator set for charging a bank of batteries. The batteries power all the machine functions including the wheel drive assemblies. When the battery reaches a certain discharge stage, the generator set will turn on and charge the batteries. This inherently smooths out the peaks and valleys of the power draw. As a result, the engine is only producing the power that the machine needs resulting in a considerably more efficient system with less emissions and quieter operation. 
     The invention is short enough in axial length as depicted in  FIG. 1  that it can be put onto a steer wheel of a vehicle without protruding too far outside the vehicle undercarriage and without protruding too far inside the vehicle undercarriage. The power density of the invention is a result of using a high speed AC motor (6000 RPM max) with a very compact high reduction gearbox and brake. High speed motors are much more compact than low speed motors for a given horsepower. The assembly is also capable of operating in an outdoor environment. The motor gearbox assembly has been designed for IP67 rating (submersible up to 1 m of water). 
     The invention includes the following features. The compact arrangement of a high speed motor, high reduction gearbox, and electromagnetic brake minimize the utilization of space. Below are some additional features of this invention. 
     Packaging the high speed (1st and 2nd stages) planetary stages within the main wheel support bearings saves space. Traditionally the high speed gearing in a planetary wheel drive gearbox is toward the cover end. By moving the high speed stages within the bearings, the three planetary stages, input  102 F, intermediate  103 F and output fit  104 F in a shorter axial length than a traditional two planetary stage assembly. In addition, with the high speed gearing away from the cover, the noise transmission to the outside environment is reduced considerably. 
     The invention as set forth in  FIGS. 1 ,  1 A,  1 B and  1 C includes nesting the brake within the winding end turns  123  of the motor  107 A which saves space. Induction AC motors traditionally have long winding end turns that normally just occupy space. The first example utilizes this axial length by nesting the brake housing  108 A within the end turns. This results in about a 1″ reduction in axial length. 
     Using the brake  108 A as a motor support piece saves space. The brake provides bearing support for the motor shaft  141 / 141 A as well as seals the motor from gearbox assembly (which contains oil). 
     Exiting the leads  129  in a sealed fashion allows use in wet environments. Power (high current) leads and low current leads that communicate power and control signals outside the motor exit the motor enclosure without breaking a seal. The low current wires exit through an overmolded grommet. 
     In the event of a power loss the brake  108 A will engage. If the machine needs to be towed, it is not necessary for the operator to remove the motor to access and release the brake mechanically. The disconnect  113 / 109  allows release from the brake with relative ease. Disconnect rod  113  is pushed inwardly/leftwardly when viewing  FIG. 1  which in turn pushes disconnect spline  109  against the force of spring  140  which releases the splined interconnection between disconnect  109  and the input sun gear which enables the wheel hub to turn freely thus moving the vehicle. 
       FIG. 2  is a cross-sectional assembly view  200  of another example of the motor-brake-gear reducer. Referring to the examples set forth in drawing  FIG. 2 , an internal brake is mounted such that the coils  230  in the housing  208 A of the brake which attracts the plate  224  are located in proximity to the spindle  201 A. In the preferred example of  FIGS. 1 ,  1 A and  1 B, the internal brake is mounted such that the coil  230  is mounted substantially within the electric motor thus saving space. 
       FIG. 2A  is an enlargement  200 A of a portion of  FIG. 2  illustrating the input planet gears  202 F and intermediate planet gears  203 F. In the example set forth in  FIGS. 2 and 2A  it will be noticed that input planet gears  202 F are the same width as the intermediate planet gears  203 F. 
     Lip seal  201 B seals the gap between the spindle/input ring gear and the wheel hub  101 D. Main bearings  201 C support the wheel hub  201 D and output ring gear  201 E for rotation relative to the spindle  201 A. Bearing nut  201 F and set screw  201 G secure the bearings  201 C in place longitudinally. 
       FIG. 2A  is an enlargement  200 A of a portion of  FIG. 2  illustrating the input planet gears  202 F and intermediate planet gears  203 F. Input carrier  202 A along with thrust plates  202 B are illustrated in  FIG. 2 . Input planet pins  202 E secure input planet gears  202 F to the input planet carrier  202 A. The input planet gears  202 F are secured to the input planet pin  202 E by plates  202 B. Bushings  203 C reside between the input planet gears and the pins  202 E. The input sun gear  210  is driven by splined  272  disconnect shaft  209 . Teeth of the input sun gear  210  intermesh  280  with teeth of the input planet gears  202 F driving the input planet gears. Retaining ring  212  retains the intermediate sun gear  216 . 
     Still referring to  FIG. 2A , input planet gears  202 F include 35 carburized teeth and are driven by carburized input sun gear  210  having 19 teeth. Input thrust plates  202 B secure input planet gears  202 F to the input planet pins  202 E. Input/intermediate planet bushings  203 C support input planet gears  202 F and intermediate planet gears  203 F. Input planet pin retaining rings  202 G secure thrust plates  202 B to input planet pins  202 E. Similarly input thrust plates  203 B secure intermediate planet gears  203 F to the intermediate planet pins  203 E. Input carrier  202 A is driven by input planet pins  202 E and the input carrier is splined  273  to intermediate sun gear  216 . Intermediate sun gear  216  includes 19 carburized teeth and drives  281  intermediate planet gears which interengage and react against teeth of internal ring gear  288  of spindle  201 A. See  FIG. 2A . 
     Intermediate sun retaining ring  212  retains input sun gear  202 F and input carrier  203 A. Snap ring  220  and output carrier  204 A retains the intermediate carrier  203 A. 
       FIG. 2  illustrates a brake  208 A. Inertia Dynamics Incorporated (hereinafter “IDI”) manufactures the spring applied-coil energized to release brake described herein. The IDI brake is adapted to be mounted to the spindle of the gear reducer. Energized coil  230  in the brake  208 A attracts ferromagnetic actuating plate  226  (sometimes referred to as the clapper) against the force of spring  264  and away from friction plate  225  to permit friction plate  225  to rotate with disconnect shaft  209 . When coil  230  is actuated plate  226  abuts body  208 A of the housing permitting rotation of the shaft  241  and of the shafts within the gearbox. Coil  230  is a direct current coil operable at 80 Volts direct current, 27 Watts. Wires supplying power to coil  230  are not illustrated in  FIG. 2  or  2 A. 
     Friction plate  225  includes friction material affixed thereto. Adhesive is used to affix the friction material to the friction plate. The friction material is located near the circumferential extent of the friction plate  225 . When the brake is applied, spring  264  urges the actuating plate  226  against the friction plate  225  and, in particular, against the friction material affixed to the friction plate which prohibits rotation of the shaft  241 . The brake is sealed  208 C against the spindle  201 A. See  FIG. 2A  to view seal  208 C. 
     Referring to  FIG. 2 , motor  207 A has a generally cylindrically shaped tapered exterior. Motor  207 A is affixed to spindle  201 A with bolts which are not illustrated. Spring  240  bears upon disconnect shaft  209  to enable disassembly of the device through removal of the cover assembly  206 A, cover thrust washer  206 B, and cover retaining ring  206 G. Once the cover  206 A, the thrust washer  206 B, and cover retaining ring  206 G are removed, internal disconnect rod  213  may be pushed inwardly and the cover may be reversed or flipped and reinstalled pushing disconnect rods  213 ,  209  leftwardly to disengage the motor and the gearbox from each other. Disconnect rod  213  is ordinarily used to support output sun gear. Motor shaft  241  is supported by bearings  242  at the generally leftward end of the motor and is supported by bearings  290  at the generally rightward end of the motor. Bearings  290  reside between stationary brake housing  208 A and shaft  241  permitting rotation of the shaft with respect to the bearing housing. Brake  208 A is affixed with bolts  261  to spindle  201 A. Motor  207 A is sealed  208 C with O-rings to prevent the intrusion of water or dust at the joint of the spindle and motor. Brake  208 A resides in the diametrical bore  296  of one end of the spindle  201 A. Bearings  290  are tensioned and retained in place by spring  208 E operable between ring  208 D residing in a groove in an inner diametrical bore of the brake and the bearing  290 . Spring  208 E urges bearing  290  against a shoulder on the exterior of the shaft  241 . Spindle  201 A includes intermediate ring gear  288 . 
     Input sun gear  210  is carburized and has 19 teeth. Input sun gear  210  is splined  272  to the disconnect shaft  209 . Input carrier  202 A is splined  273  to the intermediate sun gear  116  which in turn drives intermediate planet gears  203 F. It will be noticed that  FIG. 2  depicts input planet gears  202 F which are as equally wide as the intermediate planet gears  203 F which results in positioning the first and second planetary stages within ring gear  288  within spindle  201 A. This saves axial space within the gearbox while effectively and efficiently transmitting power and torque. 
     Input seal  208 F and brake O-ring  208 C seal the gearbox from the motor preventing unwanted lubricating oil in the motor. Wheel hub  101 D is affixed to output ring gear  201 E with bolts  201 M. Main lip seal  201 B seals between the output ring gear  201 E, hub  201 D, and the spindle/input ring gear  201 A. Main bearings  201 C interengage wheel hub  201 D and spindle  201 A enabling rotation of the wheel hub  201 D with respect to the spindle  201 A which is affixed to the vehicle and is not rotatable. Bearing nut  201 F and set screws  201 G ensure that bearings  201 C are secured against the spindle  201 A. Seals such as O-ring seal  218  are used in the gearbox where necessary. 
     Intermediate gears  203 F drive intermediate carrier  203 A which is splined  274  to output sun gear  211 . Carburized output sun gear  211  includes 25 teeth and drives  282  output planet gears  204 F which interengage teeth  288 A of the output ring gear  201 E. There are four output planet gears. Output carrier  204 A positions the output planet gears  204 F and output planet pins  204 E apart from the first (input stage) and the second (intermediate stage) and within the output ring gear  201 E. 
     Output planet carrier  204 A is stationary. Output planet gears  204 F intermesh  288 A with teeth of the output internal ring gear causing it to rotate and drive a wheel (not shown) affixed by studs  201 M and nuts (not shown). Output planet thrust washers/plates  204 B restrict the side to side movement of the output planet gears. Output planet spacer  204 D and output planet needle rollers  204 C support the output planet gears and enable rotation of the output planet gears with respect to the output planet roll pins  204 E. Output planet pins  204 G secure the output planet roll pins  204 E to the stationary output planet carrier. 
     An intermediate carrier  203 A interengages the output sun gear  211 . Intermediate planet thrust plates  203 B secure the intermediate planet gears  203 F longitudinally. Bushings  203 C are interposed between the input planet gears  202 F and the input planet pins  202 E. Bushings  203 C are interposed between the intermediate planet gears  203 F and the intermediate planet pins  203 E. 
     Planet output carrier  204 A is secured with pins  204 G to the planet output pins  204 E. Output planet thrust washers/plates  204 B secures the output planet gears  204 F against longitudinal movement. Output planet spacer  204 D separates output planet needle roller bearings which are interposed between the interior of the output planet gears  204 F and the output pins  204 E to enable rotation of the output gears with respect to the output pins. Cover assembly  206 A is retained by the cover retaining ring. Cover thrust washer  206 B interengages output sun gear  211  driven by the intermediate carrier  203 A. 
     A Sauer AC electric motor  207 A drives splined disconnect shaft  209  which in turn drives the input sun gear  210  which in turn drives the input planet gears  202 F. The motor housing  207 A is, of course affixed to the spindle  201 A. 
     The examples of  FIGS. 1 and 2  are different.  FIG. 2  illustrates a spacer  269  and an “L” shaped sleeve between motor  207 A and forged spindle/input ring gear  269  in an opening in the large spacer/cover  269 S.  FIG. 1  utilizes a different motor  107 A which is IP  67  rated. It will be noticed that brake  208 A is housed partially within the diametrical bore  296  in the end of spindle  201 A. In  FIG. 1  plates  124 ,  126  and friction plate  125  are housed within the diametrical bore  196  in the end of spindle  101 A and housing  108 A primarily resides between windings  123  of the motor and the motor shaft  141 A.  FIG. 1  also employs a narrow input planet gear  102 F which together with the reverse orientation of the brake provides a motor-brake-reducer combination which is shorter in language. The advantage of the narrower input stage is that the intermediate stage gearing can be wider. The intermediate stage gearing is wider in the first example. Spindle  101 A and spindles  201 A have the same profiles. 
       FIG. 2  illustrates a motor-brake-reducer combination which is longer than the motor-brake-reducer combination of  FIG. 1  due to the orientation of the brake outside the motor windings  223  and the wider input planet gear  202 F. Because the brake does not fit within the motor, a spacer  269  and an “L” shaped sleeve between motor  207 A and forged spindle/input ring gear  269  reside in an opening in the large spacer/cover  269 S near a wiring harness leading to the exterior of the motor.  FIG. 2  illustrates the spacer  269  and the “L” shaped sleeve  269 A extending longitudinally along the axis of the device about the thickness of the pressure plates  224 ,  226  and the friction  225 . 
       FIG. 3  is a cross-sectional assembly view  300  of another example of the motor-brake-gear reducer which is identical in many respects to the example set forth in  FIGS. 2 and 2A . Reference numerals in the 200 series in  FIGS. 2 and 2A  denote the same structure as reference numerals in the 300 series in  FIGS. 3 ,  3 A and  3 B except where discussed herein.  FIG. 3A  is an enlargement  300  of a portion of  FIG. 3  illustrating the input planet gears  301 F and intermediate planet gears  303 F.  FIG. 3A  is included for completeness and is identical to  FIG. 2 .  FIG. 3  illustrates a motor-brake-reducer combination which is slightly longer than the example illustrated in  FIG. 1  due to the orientation of the brake outside the motor windings  323  and due to the use of the Sauer  207 A motor. Because the brake does not fit within the motor  307 A, an integral spacer  369  and an “L” shaped sleeve  369 A resides between motor  307 A and forged spindle/input ring gear  369  and an opening in the large spacer/cover  369 S near a wiring harness leading to the exterior of the motor exists. Motor  307 A is affixed to spindle  101 A with bolts which are unnumbered in  FIG. 3B .  FIG. 3  illustrates the integral spacer  369  and the “L” shaped sleeve  369 A extending longitudinally along the axis of the device about the thickness of the pressure plates  324 ,  326  and the friction  325 .  FIG. 3B  is an outside perspective view of the example illustrated in  FIGS. 3 and 3A . A Sauer AC electric motor  307 A drives splined disconnect shaft  309  which in turn drives the input sun gear  310  which in turn drives the input planet gears  302 F. The motor housing  307 A is, of course affixed to the spindle  301 A. 
       FIG. 4  is a cross-sectional assembly view  400  of another example of the motor-brake-gear reducer.  FIG. 4A  is an enlargement  400  of a portion of  FIG. 4  illustrating a portion of the brake  408 A.  FIG. 4B  is an outside perspective view  400 B of the example illustrated in  FIGS. 4 and 4A .  FIG. 4  is a cross-sectional assembly view  400  of another example of the motor-brake-gear reducer which is identical in many respects to the example set forth in  FIGS. 2 and 3 . Reference numerals in the 200 and 300 series in regard to the respective  FIGS. 2 ,  2 A and  3 ,  3 A and  3 B and denote the same structure as reference numerals in the 400 series in  FIGS. 4 ,  4 A and  4 B except where discussed herein.  FIG. 4A  is an enlargement  400  of a portion of  FIG. 4  illustrating the input planet gears  401 F and intermediate planet gears  403 F.  FIG. 4A  is included for completeness and is identical to  FIGS. 2A and 3A .  FIG. 4  illustrates a motor-brake-reducer combination which is slightly longer than that shown in  FIG. 1  due to the orientation of the brake  408 A outside the motor windings  423  and the Danaher motor  408 A. Because the brake does not fit within the motor, a spacer  469  and an “L” shaped sleeve  469 A reside between motor  407 A and forged spindle/input ring gear  401 A. Motor  407 A is affixed to spindle  401 A with bolts which are unnumbered in  FIG. 4B . An opening in the large spacer/cover  469 S near a wiring harness leading to the exterior of the motor is also shown but is unnumbered.  FIG. 4  illustrates the integral spacer  469  and the “L” shaped sleeve  469 A extending longitudinally along the axis of the device and is about the same as the thickness of the pressure plates  424 ,  426  and the friction  425 .  FIG. 4B  is an outside perspective view  400 B of the example illustrated in  FIGS. 4 and 4A . A Danaher AC electric motor  407 A drives splined disconnect shaft  409  which in turn drives the input sun gear  410  which in turn drives the input planet gears  402 F. The motor housing  407 A is, of course, affixed to the spindle  401 A. 
     The operation of  FIGS. 2 ,  3  and  4  of the gear set and the brake is the same as described in connection with the example of  FIG. 1  except as described herein.  FIG. 1  is the preferred example and due to the geometry of the various components and their arrangement is the most compact and efficient motor-brake-gear reducer. 
     The overall length of the example of  FIG. 1  from left side motor covering  179  to the right side motor covering  179 A is approximately 16 inches. Similarly, the overall length of the example of  FIGS. 2 and 3  from left side motor covering  279 ,  379  to the right side motor covering  279 A,  379 A is approximately 16.3 inches. Similarly, the overall length of the example of  FIG. 4  from the left side motor covering  479  to the right side motor covering  479 A is approximately 16.6 inches. 
     A Danaher AC electric motor  407 A drives splined disconnect shaft  409  which in turn drives the input sun gear  410  which in turn drives the input planet gears  402 F. The motor housing  407 A is, of course affixed to the spindle  401 A. All of the motors  107 A,  207 A and  307 A are 6 horsepower motors. 
     In general, all gearing, bearings, planet gear shafts, are made of carburized steel while the carriers and housings are made from ductile iron or steel. The input stage carrier is made out of through hardened steel. The spindle is made from gray iron/forged steel/steel alloy and the motor housings are aluminum. 
     In general there are three input planets, three intermediate planets, and three or four output planets depending on the gearbox rating required for the application. Other configurations as to the number of gears for each stage may be employed. 
     REFERENCE NUMERALS 
     
         
           100 —cross-sectional view of torque hub with brake located partially within the electric motor 
           100 A—enlargement of a portion of  FIG. 1   
           100 B—enlargement of a portion of  FIG. 1A   
           100 C—enlargement of a portion of  FIG. 1C   
           101 A—forged spindle/input ring gear 
           101 B—main lip seal 
           101 C—series main bearings 
           101 D—hub 
           101 E—output ring gear 
           101 F—series bearing nut 
           101 G—bearing nut set screw 
           101 M—studs 
           102 A—input carrier 
           102 B—input thrust plates 
           102 D—input planet bushing 
           102 E—input planet pins 
           102 F—input planets, 35 t, carburized 
           102 G—input planet pin retaining rings 
           103 A—double wall intermediate carrier 
           103 B—intermediate planet thrust washers 
           103 C—input/intermediate planet bushings 
           103 E—intermediate planet pins 
           103 F—intermediate planet gear 
           103 G—intermediate carrier roll pin 
           104 A—4-planet output carrier 
           104 B—output planet thrust washer 
           104 C—output planet needle rollers 
           104 D—output planet spacer 
           104 E—output planet pins 
           104 F—output planet gear, 46 t 
           104 G—output planet roll pins 
           106 A—cover assembly 
           106 B—cover thrust washer 
           106 G—cover retaining ring 
           107 A—Advanced 72V AC motor, IP67 protection rating 
           107 C—motor O-ring 
           108 A—electric brake 
           108 C—brake O-ring 
           108 D—brake retaining ring 
           108 E—bearing pre-load spring 
           108 F—input seal 
           109 —splined disconnect shaft 
           110 —input sun gear, 19 t, carburized 
           111 —output sun gear, 25 t, carburized 
           112 —intermediate sun retaining ring 
           113 —internal disconnect rod 
           116 —intermediate sun gear, 19 t, carburized 
           118 —output ring gear o-ring 
           120 —thrust spacer between input &amp; intermediate carrier 
           123 —electric motor winding end turns 
           124 —pressure plate 
           125 —friction plate 
           125 A—friction material affixed by adhesive to friction plate 
           126 —actuating plate 
           128 —motor speed controls 
           129 —water seal for electrical wires 
           130 —coils in brake 
           140 —thrust spring 
           141 —motor shaft 
           141 A—motor shaft 
           142 —bearings 
           160 —threaded bolt for affixing the brake to the forged spindle/input ring gear 
           161 —spacer between electromagnetic coil and the pressure plate, one of three 
           162 —interengagement of the pressure plate against the forged spindle/input ring gear 
           163 —passageway in the friction plate  125   
           163 A—threaded interconnection with spindle  101 A 
           163 P—passageway in ferromagnetic plate  126   
           163 Q—passageway in plate  124   
           164 —spring, one of three 
           169 —gap between inner coil housing  108 A and inner plate  126  when coil is de-energized 
           171 —spline interconnecting motor shaft and disconnect shaft 
           172 —spline interconnecting disconnect shaft  109 /input sun gear  110   
           173 —spline interconnecting input carrier  102 A 
           174 —spline interconnecting intermediate carrier  103 A and output sun  111   
           178 —splined 
           179 ,  279 ,  379 ,  479 —left side motor covering 
           179 A,  279 A,  379 A,  479 A—right side motor covering 
           180 —intermeshing of input sun gear and input planet gears 
           181 —intermeshing of intermediate input sun  116  and intermediate planet gears  103 F 
           182 —intermeshing of output sun and output planet gears 
           188 —internal ring gear of spindle  101 A 
           189 —bushing operating between disconnect rod  113  and output sun gear  111   
           190 —bearings supporting motor shaft  141 A 
           196 —diametrical bore in end of spindle  101 A 
           197 —space between end of the motor windings  123  and motor shaft  141 / 141 A 
           199 —bolt affixing the body of the brake  108 A, the spacer and the plate  124  to the spindle  101 A 
           200 —cross-sectional view of torque hub with brake 
           200 A—enlargement of a portion of  FIG. 2   
           201 A,  301 A,  401 A—spindle/input ring gear (forging) 
           201 B,  301 B,  401 B—main lip seal 
           201 C,  301 C,  401 C—main bearings 
           201 D,  301 D,  401 D—hub 
           201 E,  301 E,  401 E—output ring gear 
           201 F,  301 F,  401 F—bearing nut 
           201 G,  301 G,  401 G—bearing nut set screw 
           201 M,  301 M,  401 M—studs 
           202 A,  302 A,  402 A—input carrier 
           202 B,  302 B,  402 B—input thrust plates 
           202 E,  302 E,  402 E—input planet pins 
           202 F,  302 F,  402 F—input planets, 35 t, carburized 
           202 G,  302 G,  402 G—input planet pin retaining rings 
           203 A,  303 A,  403 A—double wall intermediate carrier 
           203 B,  303 B,  403 B—intermediate planet thrust plates 
           203 C,  303 C,  403 C—input/intermediate planet bushings 
           203 E,  303 E,  403 E—intermediate planet pins 
           203 F,  303 F,  403 F—intermediate planet gear 
           203 G,  303 G,  403 G—intermediate carrier roll pin 
           204 A,  304 A,  404 A—4 planet output carrier 
           204 B,  304 B,  404 B—output planet thrust washers/plate 
           204 C,  304 C,  404 C—output planet needle rollers 
           204 D,  304 D,  404 D—output planet spacer 
           204 E,  304 E,  404 E—output planet pins 
           204 F,  304 F,  404 F—output planet gear, 46 t 
           204 G,  304 G,  404 G—output planet roll pins 
           206 A,  306 A,  406 A—cover assembly 
           206 B,  306 B,  406 B—cover thrust washer 
           206 G,  306 G,  404 G—cover retaining ring 
           207 A,  307 A,  407 A—Sauer motor 
           208 A,  308 A,  408 A—electric brake 
           208 C,  308 C,  408 C—brake O-ring 
           208 D,  308 D,  408 D—brake retaining ring 
           208 E,  308 E,  408 E—bearing pre-load spring 
           208 F,  308 F,  408 F—input seal 
           208 G,  308 G,  408 G—standoff/interconnection between outer plate  226  and electric brake 
           208 A/coil  230   
           209 ,  309 ,  409 —splined disconnect shaft 
           210 ,  310 ,  410 —input sun gear, 19 t, carburized 
           211 ,  311 ,  411 —output sun gear, 25 t, carburized 
           212 ,  312 ,  412 —intermediate sun retaining ring 
           213 ,  313 ,  413 —internal disconnect rod 
           216 ,  316 ,  416 —intermediate sun gear, 19 t, carburized 
           218 ,  318 ,  418 —output ring gear O-ring 
           220 ,  320 ,  420 —thrust spacer between input &amp; intermediate carrier 
           221 ,  321 ,  421 —disconnect retaining ring 
           222 ,  322 ,  422 —disconnect washer, outside diameter 0.524; inside diameter, 0.286; thickness, 0.047; 
           223 ,  323 ,  423 —electric motor winding end turns 
           224 ,  324 ,  424 —pressure plate 
           225 ,  325 ,  425 —brake friction 
           226 ,  326 ,  426 —plate 
           230 ,  330 ,  430 —coil in brake 
           240 ,  340 ,  440 —spring 
           241 ,  341 ,  441 —motor shaft 
           242 ,  342 ,  442 —motor bearing 
           261 —spacer between electromagnetic coil and the pressure plate, one of three 
           264 ,  364 ,  464 —spring 
           269 ,  469 —extension of forged spindle/input ring gear (forging) 
           269 A,  369 A,  469 A—“L” shaped sleeve 
           269 S,  369 S,  469 S—large spacer/cover 
           272 ,  372 ,  472 —spline interconnecting disconnect shaft  209 / 309 / 409  input sun gear  210 / 310 / 410   
           273 ,  373 ,  473 —spline interconnecting input carrier  202 A 
           274 ,  374 ,  474 —spline interconnecting intermediate carrier  203 A/ 303 A/ 404 A and output sun  211 / 311 / 411   
           274 A,  374 A,  474 A—spline interconnecting output carrier with spindle 
           281 ,  381 ,  481 —intermeshing of intermediate input sun and intermediate planet gears 
           288 ,  388 ,  488 —internal ring gear of spindle  201 A/ 301 A/ 401 A 
           290 ,  390 ,  490 —bearings supporting motor shaft 
           296 ,  396 ,  496 —internal diameter of spindle  201 A/ 301 A/ 401 A 
           300 —cross-sectional view of torque hub 
           300 A—enlargement of a portion of  FIG. 3   
           300 B—perspective view of the torque hub 
           369 —integral extension of the spindle 
           400 —cross-sectional view of torque hub 
           400 A—enlargement of a portion of  FIG. 4   
           400 B—perspective view of the torque hub 
       
    
     The invention has been set forth by way of example. Those skilled in the art will readily recognize that changes may be made to the invention without departing from the spirit and the scope of the appended claims.