Abstract:
Several embodiments of a wobble plate motor include a disc mounted on a bent shaft. Driving the wobble plate so it revolves on a flat base causes the bent shaft to rotate and drive a generator or other work consumer. The wobble plate may be driven by a fluid stream impinging on the plate or by a blade assembly in a path of fluid movement. In one embodiment of a bladed motor, a shroud may direct the fluid stream so it more efficiently cooperates with the blade assembly.

Description:
[0001]    This application is partly based on Provisional Application Ser. No. 61/848,623, filed Jan. 7, 2013, the priority of which is claimed and is a continuation-in-part of application Ser. No. 12/583,368, filed Aug. 19, 2009. 
     
    
       [0002]    This invention relates to a wobble plate or swash plate motor and more particularly to a such a motor driven by a high inertia fluid stream. 
       BACKGROUND OF THE INVENTION 
       [0003]    There has been considerable development of gas turbine driven electrical generators. Typical modern devices incorporate several energy recovery techniques including making steam with heat from hot exhaust gases exiting from the gas turbines. 
         [0004]    Wobble plate or swash plate devices are known in the prior art where a wobble plate comprises a transmission between a device applying a force to the wobble plate and an output device. Thus, the wobble plate devices are transmissions between a prime mover and an output device, some of which are pumps. The force applied to wobble plate is often by a cylinder or piston. 
         [0005]    Other bladed motors of various types are also known in the prior art. 
       SUMMARY OF THE INVENTION 
       [0006]    In one aspect, an inclined plate is mounted on a bent rotatable shaft and rotated so the plate rolls on a planar surface. Thus, the plate may roll on a base or track and cause rotation of the shaft which may be connected to a work consumer, such as an electrical generator, pump, compressor or the like. When rolling on the base, the inclined plate moves in a manner analogous to a spinning coin as it begins to decay, i.e. when the spin rate slows to a value where the coin is inclined to its axis of rotation. This type motion has been defined as nutation, i.e. the disc nutates. 
         [0007]    In some embodiments, the track on which the inclined plate runs is of a non-skid design so the inclined plate does not skid but is, instead, induced to roll on its track. It may be preferred to provide the track and plate with gear teeth providing the non-skid device. 
         [0008]    A force is applied to the inclined plate in any suitable manner causing it to roll on its base. In one embodiment, nozzles direct a propulsion fluid only onto segments of the plate that drive it in the same direction. In some embodiments, energy may be recovered from a rapidly moving fluid stream, such as the exhaust of a gas turbine, or a slower stream of higher fluid density, such as a moving liquid. 
         [0009]    In another embodiment, a wobble blade assembly is mounted in a housing and includes a fan or blade assembly which is rotatably mounted on the end of a bent drive shaft. The drive shaft includes an opposite end mounted for rotation in a suitable support in the housing. A gear fixed to the housing meshes with teeth on the periphery of the fan blade assembly. A moving fluid stream passes through the housing and impacts the blade assembly to induce rotation of the blade assembly around the fixed gear thereby rotating the drive shaft. The drive shaft may be coupled to a work consuming device, such as an electrical generator, pump or the like. 
         [0010]    It is an object of this invention to provide a wobble plate motor in which an inclined plate is mounted on the end of a bent shaft. 
         [0011]    Another object of this invention is to provide a wobble plate motor in which high pressure fluid is applied directly to a section of the wobble plate thereby rotating the wobble plate and driving a work consumer. 
         [0012]    A further object of this invention is to provide a wobble plate motor operated by a bladed rotor drive by a stream of moving fluid. 
         [0013]    These and other objects and advantages of this invention will become more fully apparent as this description proceeds, reference being made to the accompanying drawings and written description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a front view of one embodiment of a wobble plate motor, certain parts being broken away for clarity of illustration; 
           [0015]      FIG. 2  is a cross-sectional view of the wobble plate motor of  FIG. 1 , taken in a plane defined by the bent shaft; 
           [0016]      FIG. 3  is a schematic top view of the motor of  FIGS. 1-2  illustrating one technique for applying fluid pressure to only one side of the plate; 
           [0017]      FIG. 4  is a front view of another embodiment of a wobble plate motor, certain parts being broken away for clarity of illustration; 
           [0018]      FIG. 5  is a side view of the motor of  FIG. 4 , certain parts being broken away for clarity of illustration; 
           [0019]      FIG. 6  is a front view of a modified form of the embodiment of  FIGS. 4-5  illustrating a shroud in front of the fan assembly to control fluid flow; 
           [0020]      FIG. 7  is a side view of the motor of  FIG. 6 , certain parts being broken away for clarity of illustration. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Any of the embodiments may be driven by a high inertia fluid stream. The fluid stream may be a liquid stream moving at a moderate velocity or a gas or vapor stream moving at higher velocity. In one application, the gas stream may be the exhaust of a gas turbine, such as of the type used to drive large electrical generators. One of the advantages of this invention is that energy is taken from the inertia of the fluid stream, such as by reducing the velocity of a gas stream, without substantially changing the temperature of the gas stream significantly. In this manner, this invention may be used in conjunction with a thermal energy recovery system, as by using the hot exhaust gases exiting from this device in a steam cycle. 
         [0022]    Referring to  FIGS. 1-3 , there is illustrated a simplified wobble plate motor  10  illustrating its principles of operation. The motor  10  comprises a plate or disc  12  journalled or rotatably mounted by a bearing assembly  14  on a bent end  16  of a shaft  18  rotatably mounted by a bearing assembly  20  in a planar base  22  perpendicular to the shaft  18 . If necessary or desirable, the bearing assemblies  14 ,  20  may include thrust elements to counteract any tendency of the shaft  18  to move axially. The concept is that a force applied to only one segment of the disc  12 , as in the direction of the arrow  24 , causes the disc  12  to roll on the planar base  22  and thereby rotate the shaft  18  in the direction shown by the arrow  26  thereby driving an input to a work consumer such as an electrical generator, pump, compressor or the like. 
         [0023]    Thus, the plate  12  rotates about an axis  28  of the shaft  18  in a manner analogous to a spinning coin as it begins to decay, i.e. as the spin rate slows to a value where the coin is inclined to its axis of rotation. In other words, the plate  12  nutates as it rolls on a track provided by the base  22 . 
         [0024]    The force applied to the plate  12  is generated by a differential pressure applied directly to the plate  12  as contrasted to a pressure generated force applied through a cylinder, piston or other mechanical device. Although the differential pressure may be the difference between atmospheric pressure and a partial vacuum, it may be preferred to provide a positive pressure to only one segment of the disc  12  because much greater positive pressures are more readily available and produce much greater torque on the output shaft  18 . Although the power fluid may be a liquid, it may be preferred to use a gas, such as steam which is readily available in some industrial environments of which one example is the exhaust from steam turbines. 
         [0025]    As shown in  FIG. 1 , an imaginary plane  30  is defined by the shaft  18  and its bent end  16  to divide a front  32  of the disc  12  into two segments  34 ,  36  to divide the back of the disc  12  into two segments  38 ,  40 . It will be seen that a force applied in the direction of the arrow  24  to the segment  34  causes the disc  12  to rotate in the direction shown by the arrow  26 , as does a force applied to segment  40  in the direction shown by the arrow  42 . In other words, forces represented by the arrows  24 ,  42  cause rotation of the disc  12  in the same direction, i.e. as shown by the arrow  26 . Similarly, forces applied to the segments  36 ,  38  cause rotation of the disc  12  in the direction opposite to the arrow  26 . Thus, the segments  34 ,  40  may be considered complementary or additive and the segments  36 ,  38  may be considered opposite or subtractive relative to the segments  34 ,  40 . The various segments  34 ,  36 ,  38 ,  40  suggest a myriad of ways in which pressures, or partial vacuums, may be applied to the disc  12  to induce rotation of the shaft  18  in a desired direction. 
         [0026]    As used herein, saying that pressure is applied to only one segment of the disc  12  may mean that the disc is subject to greater pressures inducing rotation in one direction rather than in the other direction, such as will occur when high pressure is applied to one segment of the disc  12  and atmospheric pressure is applied to an opposite or subtractive segment. 
         [0027]    There are a variety of ways to apply pressure to only one segment of the plate  12  and not to its opposite. As shown in  FIG. 1-3 , one or more horizontal arrays of nozzles  44  may be supported in any suitable manner, such as on a ring header  46 , about the disc  12  so that one or more nozzles  44  is always aimed at or near a given point on the disc  12  such as the imaginary marking 270°. The nozzles  44  are actuated sequentially so that one or more of them discharge power fluid onto the plate  12  toward one or more of the selected plate segments inducing rotation in the desired direction. This may be accomplished in any suitable manner, a simple version of which may be that each nozzle includes a valve  46  having a sensor, such as a feeler, positioned to be tripped by an edge or a detectable marker on the plate  12  as it approaches the nozzle  44  to deliver high pressure fluid from a source  49 . 
         [0028]    Each of the nozzles  44  is connected by a valve  48  to a pressure source  49  so by judiciously operating selected ones of the valves  48 , a high pressure fluid is delivered through the nozzle  44  aimed at the 270° mark, the disc  12  will rotate or nutate about the axis  18  in the direction of the arrow  26 . The nozzles  44  may extend completely around the disc  12  as shown in  FIG. 3  so one or more of the nozzles  44  aimed at the back  38  of the disc  12  may simultaneously be actuated to deliver power fluid to the back of the imaginary marking 90°, i.e. at the complementary segment  40 . This effectively doubles the force applied to the disc  12  and thus doubles the usable output of the shaft  18 . 
         [0029]    Operation of the motor  10  will now be described. When motive fluid is delivered by the nozzles  44  to the segment  34  and/or to the segment  40 , the disc  12  rolls on the base  22  because the pressure and thus the force applied to the complementary disc segments  34 ,  40  is greater than atmospheric pressure acting on the subtractive segments  36 ,  38 . This rotates the shaft  18  and provides torque and horsepower to operate a work consuming device. 
         [0030]    Referring to  FIGS. 4-5 , there is illustrated another embodiment comprising a motor  50  having a member  52  such as a plate, disc, tube or the like journalled or rotatably mounted by a bearing assembly  54  on a bent end  56  of a shaft  58  rotatably mounted about an axis  60  by a bearing assembly  62  in a planar base  64 . If necessary or desirable, the bearing assemblies  54 ,  62  may include thrust elements to counteract any tendency of the shaft  58  to move axially. From one point of view, the concept is that a force applied to the disc  52 , as in the direction of the arrow  66 , causes the plate  52  to roll on the planar base  64  and thereby rotate the shaft  58  in the direction shown by the arrow  68  thereby driving an input to a work consumer such as an electrical generator, pump, compressor or the like drivably connected to the shaft end  70 . From another point of view, the concept is that a force applied to the disc  52 , as in the direction of the arrow  66 , causes the shaft  58  to rotate in the direction of the arrow  68  while the plate  52  cooperates with the base  64  to constrain movement of the shaft end  70  into simple rotary movement about the axis  60 . 
         [0031]    The member  52  may preferably include a ring or rim  72  and a plurality of radiating struts  74  providing a receptacle for the bearing  54 . This allows the motive fluid to flow through the member  52  for purposes more fully apparent hereinafter. The base  64  may be of similar construction providing a ring  76  and a series of radiating struts  78 . To make the plate  52  roll on the base  64  without slipping, a gear or gear teeth  80  on the plate  52  may mesh with a gear or gear teeth  82  on the base  64 . It will be seen that the gear teeth  80 ,  82  provide complementary bevel gears. It will also be seen that the rings  72 ,  76  may be of equal diameter or may be of different diameter, meaning that the gears  80 ,  82  may be of different or the same diameter. 
         [0032]    The motor  50  may be positioned in a housing  84  of any suitable type and is illustrated as a simple tubular housing having a passage  86 , an inlet end  88  and an outlet end  90 . The struts  78  may extend to connect to the housing  84  thereby positioning the motor  50  at a desired location. The plate  52  and base  64  may accordingly comprise latticework arrangements in the sense that a fluid flowing through the housing passage  86  is only minimally obstructed. 
         [0033]    Driving the shaft  58  or the plate  52 , depending on ones view, is a blade assembly  92  mounted on the bent end  56  of the shaft  58 . The blade assembly  92  may include the bevel gear provided by the teeth  80 . The blade assembly  92  may include a hub  94  and a series of blades  96  radiating away from the hub  94 . The blade assembly  92  is fixed to the gear  80  and the blades  96  are inclined so that, on one side of the blade assembly  92 , the blades  96  present a more-or-less solid appearance (such as on the left in  FIG. 4 ) and a more-or-less open appearance (such as on the right of  FIG. 4 ). As the plate  52  nutates on its circular edge around and in cooperation with the ring  76 , the plate  52  and shaft rotates relative to each other as allowed by the bearing  54 . Manifestly, the inclination of the blades  96  can be reversed to cause rotation of the blade assembly  92  in the opposite direction. As an alternative, the blades  96  may be of airfoil shape and suitably positioned to produce torque to drive the plate  52  and the shaft  58 . 
         [0034]    High inertia fluid flowing through the passage  86  in the direction shown by the arrow  100  impacts the blades  96  on the left in  FIG. 4  and tends to flow freely through the blades  96  on the right in  FIG. 4 . This pushes the blade assembly  92  to the left in  FIG. 4  causing nutation of the blade assembly  92  as it tracks along the stationary bevel gear  82 . The axial shaft  70  is accordingly rotated and may be connected to a work producing device such as an electrical generator, pump or the like thereby producing work. It will accordingly be seen that the blade assembly  92  nutates during operation of the motor  50  thereby rotating the output shaft  70 . 
         [0035]    There is a tendency of air flowing through the passage  86  to bypass the blade assembly  92  reducing the efficiency of the motor  50 . It may be preferred to provide a shroud  110  to divert air through the blade assembly  92  as shown in the embodiments of  FIGS. 6 and 7 . The shroud  110  may act as a flow director, directing flow only toward the blades  96  which are transverse to, or side-on to, the direction of flow through the housing  84 . The shroud  110  may also act as a flow accelerator as will be more fully apparent hereinafter. 
         [0036]    The shroud  110  may take a number of suitable forms and may include a plate  112  having an opening  114  aligned with those fan blades  96  that are side-on to the direction of flow as suggested in  FIG. 6 . 
         [0037]    An important advantage of the embodiment of  FIGS. 6-7  is that rotation of the plate  112  and the opening  114  remains synchronized with nutation of the fan assembly  92  so the opening  114  always aligns with the side-on blades. To this end, the plate  112  may rotate at the same rate, or synchronously, with nutation of the fan assembly  92 . This is much easier to accomplish when the gears provided by the teeth  80 ,  82  are the same size because this means that the member  52  nutates and the plate  112  rotates at the same rate. 
         [0038]    The plate  112  may be fixed on a shaft end  115  by a coupling  117  coaxial with the axis  60 . The shaft end  115  is part of a bent shaft  116  having an inclined end  118  rotatably mounted on the inclined shaft end  56  by a coupling  120 . It will be seen that rotation of the fan assembly  92  causes the inclined shaft end  56  to rotate in a circle  122 . This causes the inclined end  118  of the shaft  116  to rotate thereby rotating the plate  112  and maintaining the opening  114  aligned with that segment of the blades  96  that act to rotate the fan assembly. The shroud  110  accordingly increases the efficiency of the motor  50  by reducing fluid bypass around the blade assembly  92 . It will also be apparent that the opening  114  restricts the area of flow immediately upstream of the blade assembly  92  thereby increasing the velocity of the fluid stream impacting the side-on blades. 
         [0039]    The motors  10 ,  50  are effective in producing work from moving fluid streams of different density, such as air and water, and from fluid streams moving at much different velocities. 
         [0040]    The exhaust stream from gas turbine engines is quite high, perhaps too high for efficient use in some of the embodiments disclosed herein. In this event, the exhaust stream may be split and run through motors which are essentially parallel, the size of the passage through which it flows may be increased to decrease the velocity or in some other arrangement. In addition, the exhaust stream may be of sufficient velocity that substantial energy remains after passing through one of the motors disclosed herein. 
         [0041]    In this event, motors may be placed in series, depending on the tradeoff between efficient use of available energy, capital costs, operating costs and the like. 
         [0042]    It will be apparent that suitable seals may be provided at desired locations to minimize leaking of the driving fluid, suitable bearings may be provided to increase reliability and performance and other engineering solutions may be provided to overcome problems which may become apparent. 
         [0043]    It will be seen that the discs  12 ,  52  may be circular or of other smooth arcuate periphery so long as the base  22 ,  64  is either planar in the case of a circular disc or of complementary shape in the case of a smoothly arcuate periphery, such as an ellipse. It will also be seen that the discs  12 ,  52  are at an acute angle relative to the bases  22 ,  64 . 
         [0044]    Although this invention has been disclosed and described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms is only by way of example and that numerous changes in the details of operation and in the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.