Patent Abstract:
A wheel driven utility vehicle includes a frame and two small volume high speed alternating current electric motors arranged side by side for driving the vehicle. Alternatively high speed direct current, hydraulic or pneumatic direct current motors may be used with suitable controls. Each motor has an output shaft which drives an offset planetary gear reducer. Each offset planetary gear reducer is affixed to the electric motor and includes an output carrier interconnected with an output shaft. Each output shaft includes first and second chain drive sprockets which drive chains interconnected with shafts driving the front and rear wheels respectively. Each offset planetary gear reducer enables use of space saving high speed relatively low-torque alternating current electric motors with attendant large speed reductions. Gear reduction enables the production of sufficient torque at the wheels of the vehicle. Applications in addition to utility vehicles are also specifically contemplated.

Full Description:
FIELD OF THE INVENTION 
       [0001]    The invention is in the field of offset drive systems for utility vehicles. In particular, this invention is in the field of utility vehicles (such as Skid-Steer® and Bobcat® vehicles), fork lifts and front end loader machines. 
       BACKGROUND OF THE INVENTION 
       [0002]    Traditionally, Skid-Steer® Loader Machines as made famous by manufacturers such as Bobcat® and the like have been powered almost exclusively by hydraulics. Skid-Steer® is a registered trademark of Arts-way Manufacturing Co., Inc., a Delaware Corporation. Bobcat® is a registered trademark of Clark Equipment Company of New Jersey. 
         [0003]    These machines traditionally have gasoline or diesel internal combustion engines that drive a hydraulic pump. The pump usually provides power to two independently controlled hydraulic motors one for each side of the machine. The output of each motor drives a drive sprocket with two sets of sprocket teeth. One set of sprocket teeth drives a chain that goes to a front wheel sprocket and the other set of sprocket teeth drives a chain that goes to the rear wheel sprocket. The hydraulic pump also provides power for lifting functions and power takeoffs for implements that can be connected to the machine. 
         [0004]    U.S. Pat. No. 4,705,449 to Christianson et al. discloses the use of two electric traction motors.  FIG. 1  is a plan view of an electric drive system of U.S. Pat. No. 4,705,449 to Christianson et al. wherein battery  28  supplies electric power to two traction motors  60 ,  64  which in turn are coupled  84  to a gear reducer  82 . Specifically, the &#39;449 patent states at col. 4 line 10 et seq.: “a first traction motor 60 provides the motive force for the left-hand side of the vehicle and a second traction motor 64 provides the motive force for a right-hand side of the vehicle 66. Both the first traction motor 60 and the second traction motor 64 are powered by a battery pack 28 . . . . Similarly, the traction motor 64 is connected to a spur gear reduction assembly 82 through a coupling 84. The spur gear reduction assembly engages a chain 86 which in turn engages a right rearward gear 74 and left forward gear 90, which are respectively connected to wheels 14a and 14b through axles 92 and 94. As will be appreciated, the traction motor 60 is operated independently of the traction motor 64 thereby permitting the wheels 14c, 14d to operate at different speed than wheels 14a and 14b to create skid steering.”. 
         [0005]    U.S. Pat. No. 4,705,449 to Christianson et al. discloses the use of two electric traction motors. The motors are not identified by type in Christianson et al as either DC or AC. However, the motors are DC electric motors as they are controlled by a device identified in the &#39;449 patent to Christianson, namely, a General Electric EV 1 SCR Controller, which is designed to control DC motors. The General Electric EV 1 SCR Controller describes the use of rectifiers to pulse power to DC motors and has no provision for the control of AC motors. 
         [0006]    A copy of the EV 1 SCR Controller technical literature is submitted herewith in an Information Disclosure Statement and describes the use of the controller as being for the control of DC motors. Additionally, the EV 1 SCR Controller is identified in U.S. Pat. No. 4,265,337 to Dammeyer entitled Fork Lift Truck Speed Control Upon Fork Elevation and is used to control a DC motor  92 . 
         [0007]    Additionally, the EV 1 SCR Controller has been used in numerous automobiles (electric vehicles) in conjunction with DC series wound motors which provide high current and high torque at low rpm. 
         [0008]    DC traction motors have been used in applications involving forklifts and similar vehicles in the past. Internal combustion engines are not favored in such applications because an internal combustion engine produces zero torque at zero engine speed (RPM) and reaches its torque peak later in its operating range. Internal combustion engines generally require a variable-ratio transmission between the engine and the wheels to match engine speed to the road speeds and loads encountered. A clutch must be provided so that the engine can be mechanically decoupled from the wheels when the vehicle stops. Additionally, some slippage of the engine with respect to the drive train occurs while starting from a stop. Direct current electric traction motors produce considerable torque at zero RPM and thus may be connected directly to the wheels. Alternating current motors, hydraulic motors and pneumatic motors also produce torque at zero RPM. 
         [0009]    Although the term traction motor is usually referred to in the context of a direct current motor, the term is also applicable to alternating current motor applications as well. Additionally, the term traction motor is used to describe any motor of whatever type used to supply torque and power to a vehicle&#39;s wheel, tracks, etc. 
         [0010]    In small utility vehicles and the like, space is an important consideration in the design of the vehicle. It is therefore desirable to use a small motor, electric, hydraulic, or pneumatic which is capable of supplying required torque and horsepower under all operating conditions. If an electric motor is used it may be an alternating current motor or it may be a direct current motor. 
         [0011]    Generally, for a given power, high speed electric motors are smaller in size, lighter in weight, and less expensive than low speed motors. Generally, for a given power, alternating current motors are smaller than direct current motors. 
         [0012]    Therefore, it is highly desirable to save space, weight and cost in the powertrain of a utility vehicle through the use of a high speed motor so that the space may be used for batteries, controls or other components. 
       SUMMARY OF THE INVENTION 
       [0013]    As electric motor technology has advanced to provide more performance for less cost it makes sense to replace hydraulic systems with electric systems. Electric motors typically rotate at much higher RPM than hydraulic motors, particularly those suitable for skid-steer loaders. It is desirable to minimize the size of the drive train components so as to maximize the space available for batteries and controls. The vehicle described herein may employ Nickel Metal Hydride, Lithium Ion, Lithium Ion polymer, lead acid batteries or other battery technology. 
         [0014]    Although one example of the invention as described herein uses high speed alternating current electric motors it is specifically contemplated that the invention may be used with high speed direct current electric motors, high speed hydraulic motors and high speed pneumatic motors. 
         [0015]    The input to the gear box is an offset helical gear driven by a pinion. A planetary sun pinion inputs to the planetary stage. Planetary gear sets provide torque multiplication in compact packages. The output of the gear box is a carrier with a planetary gear-set reduction including a stationary ring gear. The gear box casing includes a ring gear which is a reaction gear and intermeshes with a three-gear planetary set. The carrier of the planetary gear set includes a spline which intermeshes with a splined output shaft. 
         [0016]    The offset reduction in the gearbox is an important aspect of the invention as it enables the electric motors to be placed side to side. Use of electric motors is enabled in this application by offsetting the gear box. In this way the left and right side motors can be mounted side-by-side without interference while still maximizing available space for other components such as batteries and controls. 
         [0017]    In another example, the offset gear box may be oriented differently (i.e., rotated 180 degrees) with the motors side by side. Although this example may result in reducing the width of the vehicle it may also result in increasing the length of the vehicle. Still alternatively, this example may be used to drive one of the wheel shafts directly. 
         [0018]    A wheel driven utility vehicle includes a frame and two high speed alternating current electric motors arranged side by side for driving the vehicle. A variable frequency alternating current drive is utilized to control the speed of the motors and hence to control the direction and turning of the utility vehicle. Instead of high speed alternating current motors, high speed direct current motors, high speed hydraulic motors and/or high speed pneumatic motors may be used. 
         [0019]    Each alternating current motor has an output which drives an offset planetary gear reducer. Each offset planetary gear reducer is affixed to the electric motor (or other motor type) and includes an output carrier interconnected with an output shaft. Each output shaft includes first and second chain drive sprockets which drive chains interconnected with shafts driving the front and rear wheels respectively. Each offset planetary gear reducer enables use of space saving high speed relatively low-torque alternating current electric motors (or other motors with similar performance characteristics) with attendant large speed reductions. Gear reduction enables the production of sufficient torque at the wheels of the vehicle. Applications in addition to utility vehicles are also specifically contemplated. 
         [0020]    A utility vehicle drive system comprises two alternating current electric motors (or other high speed motors with similar performance characteristics) each having a shaft driven pinion gear. Intermediate gears engage shaft driven pinion gears which in turn drive planetary gears. Each of the planetary gear reducers include an output spline and each of the output splines are axially aligned with each other. 
         [0021]    A method for using a high-speed electric motor (or high-speed hydraulic, pneumatic or direct current motors) in a utility vehicle includes the step of orienting the motors having shaft driven pinion gears side by side such that their shaft driven pinion gears are arranged on opposite sides of the vehicle. Next, the offset planetary gear reducers are mounted in engagement with the shaft driven pinion gears. Each of the planetary gear reducers include a gear driven by the shaft driven pinion gear. The gear driven by the shaft driven pinion gears includes a shaft portion formed as a second pinion sun gear which drives a planetary gear set and carrier. The planetary gear set reacts against a ring gear in the casing of the planetary gear reducer. The carrier of the planetary gear reducer includes a splined output. Each of the splined outputs are on the same axis of the other splined output located on the other side of the vehicle. Additionally, the method includes driving an output shaft coupled to the splined output of the carrier of the planetary gear reducer. And, finally, the method includes driving, with chains, the wheel shafts of the vehicle. 
         [0022]    It is an object of the present invention to save motor space in a utility vehicle, recreational vehicle, and the like while providing for high torque at the vehicle wheel and tire. 
         [0023]    It is an object of the present invention to provide a planetary gear reducer in a utility vehicle, recreational vehicle and the like which enables use of a smaller, lighter, high speed motor while providing for high torque at the vehicle wheel and tire. 
         [0024]    It is an object of the present invention to provide a planetary gear reducer in a utility vehicle, recreational vehicle and the like which enables use of a smaller lighter high speed motor selected from the group of alternating current motors, direct current motors, hydraulic motors, and pneumatic motors. 
         [0025]    It is an object of the present invention to provide a planetary gear reducer in a utility vehicle, recreational vehicle and the like which enables use of a smaller, lighter, high speed alternating current electric motor while providing for high torque at the vehicle wheel and tire. 
         [0026]    It is an object of the present invention to provide for an efficient planetary gear reducer for use in a utility vehicle, recreational vehicle and the like. 
         [0027]    It is an object of the present invention to provide for two offset electric motors in a utility vehicle, recreational vehicle, and the like by utilizing two offset planetary gear reducers. 
         [0028]    It is an object of the present invention to utilize high speed alternating current motors in a utility vehicle, recreational vehicle or the like. 
         [0029]    It is an object of the present invention to provide a method of using two high speed electric motors. 
         [0030]    It is an object of the present invention to provide offset planetary gear reducers for use in combination with high speed motors for efficient use of space in a utility vehicle. 
         [0031]    It is an object of the present invention to provide offset planetary gear reducers for use in combination with alternating current electric motors for efficient production of torque at the wheels of a utility vehicle. 
         [0032]    These and other objects of the invention will best be understood when reference is made to the Brief Description of the Drawings, Description of the Invention and Claims which follow hereinbelow. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]      FIG. 1  is a plan view of a prior art Skid-Steer vehicle powered by two DC traction motors. 
           [0034]      FIG. 2  is a top plan view of the utility vehicle illustrating two alternating current motors oriented side by side with each having an offset planetary gear reducer driving a respective output shaft. 
           [0035]      FIG. 2A  is an enlarged portion of  FIG. 2  illustrating a portion of the left side of the vehicle. 
           [0036]      FIG. 2B  is an enlarged portion of  FIG. 2A  illustrating the gear reducer and output shaft. 
           [0037]      FIG. 2C  is an exploded view of the input to the gear reducer, the gear reducer, and the output shaft. 
           [0038]      FIG. 2D  is a perspective view of the carrier and the output shaft. 
           [0039]      FIG. 2E  is a perspective view of the offset planetary gear speed reducer. 
           [0040]      FIG. 3  is a block diagram of the method for using high speed alternating current electric motors with offset planetary gear reducers. 
       
    
    
       [0041]    The drawings will be best understood when reference is made to the Description of the Invention and Claims below. 
       DESCRIPTION OF THE INVENTION 
       [0042]      FIG. 2  is a top plan view  200  of the utility vehicle illustrating two alternating current electric motors  201 ,  202  oriented side by side with each having an offset planetary gear reducer  203 ,  204  driving a respective output shaft  208 ,  214 . Although reference numerals  201 ,  202  refer to high speed alternating current electric motors, it is specifically contemplated that other high speed motor types may be used such as direct current motors, hydraulic motors and pneumatic motors. 
         [0043]    The utility vehicle includes a frame  205 ,  206 ,  250 ,  251  for supporting vehicle components. As illustrated in  FIG. 2 , side frame member  205  is on the left hand side of the vehicle and side frame member  206  is on the right hand side of the utility vehicle. The two side frame members  205 ,  206  are shown in section in  FIG. 2 ,  FIG. 2A , and  FIG. 2B . 
         [0044]    Frame side member  205  supports first chain driven wheel shaft  210 . Sprocket  210 S is formed as part of the wheel shaft  210  or alternatively is a separate sprocket affixed or attached to the wheel shaft  210 . Frame side member  205  also supports the output shaft  208  of the planetary gear reducer  203 . 
         [0045]    Output shaft  208  includes two sprockets  208 S which are identical. The sprockets  208 S may be an integral part of shaft  208  or they may be separately attached to the shaft. A metal chain  210  interengages sprockets  210 S and  208 S and communicates horsepower and torque therebetween. The reduction ratio of output shaft driving sprocket  208 S to driven sprocket  210 S is approximately 2.5-5:1 such that for every rotation of the output shaft  208  the forward sprocket  210 S and wheel shaft  210  turns 0.4 to 0.2 of a turn or revolution. Reduction in speed of the driven sprocket  210 S results in a corresponding increase in torque for a given applied power. 
         [0046]    Referring to  FIGS. 2 and 2B , output shaft  208  is splined and is coupled to the splined output  230 T of the carrier  230  of the planetary gear reducer  203 . Frame side member  205  also supports the second chain driven wheel shaft  212 . Sprocket  212 S is formed as part of the wheel shaft  212  or alternatively is a separate sprocket affixed or attached to the wheel shaft  212  for driving a rearward wheel  212 A. 
         [0047]    Metal chain  211  interengages sprockets  212 S and  208 S and communicates horsepower and torque therebetween. The reduction ratio of the output shaft driving sprocket  2085  to driven sprocket  2125  is approximately 2.5-5:1 such that for every rotation of the output shaft  208  the rearward sprocket  212 S and wheel shaft  212  rotates just 0.4 to 0.2 of a turn or revolution. The reduction in speed of the driven sprocket  212 S results in a corresponding increase in torque for a given applied power. 
         [0048]    Similarly, the structure and operation of driven sprockets  2165 ,  2175 , shafts  216 ,  217 , frontward and rearward wheels  216 A,  217 A, sprockets  214 S, shaft  214  and chains  213 ,  215  on the right side and within the right frame  206  are identical to the left frame side member  205  and frame  205 . The reduction ratio of the output shaft driving sprocket  214 S to driven sprockets  216 S,  217 S is the same as in connection with the left side of the vehicle, namely, approximately 2.5-5:1. 
         [0049]    Speed reduction of approximately 2.5-5:1 just described are in addition to the speed reduction of the planetary gear reducers  203 ,  204  which are described further herein. Alternating current motors  201 ,  202  reside side by side and have output shafts  221 S,  222 S with pinion gears  221 ,  222  thereon for driving two offset planetary gear reducers  203 ,  204  to effect speed reduction and increase torque. Alternatively, a helical pinion gear  221 H and a helical driven gear  223 H. Full load electric motor torque is generally defined as follows: 
         [0000]      Torque(ft-lbs.)=5250×horsepower/RPM
 
         [0050]    Generally, for a given power, high speed electric motors are smaller in size, lighter in weight, and less expensive than low speed motors. Generally, for a given power, alternating current motors are smaller than direct current motors. Additionally, for a given power, alternating current motors are smaller than direct current motors. 
         [0051]    Use of planetary gear reducers  203 ,  204  with alternating current motors  201 ,  202  saves space. As previously stated the motors may be hydraulic, pneumatic or direct current motors. Reducers  203 ,  204  are approximately 8 inches in diameter and approximately 5.5 inches deep and occupy a volume of approximately 300 cubic inches. 
         [0052]      FIG. 2A  is an enlarged portion  200 A of  FIG. 2  illustrating a portion of the left side of the vehicle and  FIG. 2B  is a further enlargement of a portion  200 B of  FIG. 2A  illustrating the gear reducer  203  and pinion  221  on output shaft  221 S in more detail. 
         [0053]    Referring to  FIGS. 2A and 2B , the alternating current motors  201 ,  202  are controlled by a variable frequency drive (not shown) to control the speed of the motors. Preferably the alternating current motors are three phase motors. Each of the offset planetary gear reducers  203 ,  204  include a housing having a ring gear  224  affixed thereto. Ring gear  224  is trapped between housing portions  203 ,  203 A of the reducer. Seals  224 S prevent leakage of lubricant from within the gear casing. 
         [0054]    Each of the planetary gear reducers  203 ,  204  includes a carrier  230  having planetary gears  225 ,  226 ,  229  intermeshing with the ring gear  224  and an output spline  230 T. Although the planetary gear reducer illustrated has three planetary gears, any reasonable number of planetary gears may be used. Each of the planetary gear reducers includes a gear  223  having teeth  223 T driven by the pinion gear  221  of the output shaft  221  of the alternating current motor  201 . The gear  223  driven by the pinion gear  221  of the output shaft  221 S of the alternating current motor  201  includes a shaft portion forming a sun pinion  227  with gear teeth  227 T. 
         [0055]    Sun pinion or gear  227  intermeshes with three planet gears  225 ,  226 , and  229  each of which naturally include teeth  225 T,  226 T and  229 T which intermesh with ring gear  224 . Ring gear  224  extends around the inner circumference of the gearbox. Each of the chain drive shafts  208 ,  214  includes a spline  208 T thereon which intermeshes with output spline  230 T of the carrier  230  as best viewed in  FIG. 2B . Planetary gear reducers  203 ,  204  effect a speed reduction in the approximate range of between 20-30:1. That is for every revolution of the input pinion gears  221 ,  222 , the carrier  230  will rotate 1/20 to 1/30 of a revolution. Other speed reductions are specifically contemplated. Chain drive sprockets  208 S,  214 S in combination with wheel shaft sprockets  210 S,  212 S,  216 S and  217 S effect a speed reduction in the approximate range of 2.5-5:1. That is, for every one rotation of the chain drive sprocket  208 S, the wheel sprockets  2105 ,  2125  will rotate 0.4 to 0.2 of a revolution. Other speed reductions are specifically contemplated. Since torque is inversely proportional to the shaft rotational speed, torque is increased with a reduction in speed. 
         [0056]    Other speed reductions are specifically contemplated depending on the desired torque at the wheels and traveling speed of the machine taking loads, inclines and other variables into consideration. Use of the offset speed reducer as disclosed herein enables the efficient use of space and provides the same torque to the wheel with less input torque supplied by the high speed electric motor. The efficiency of the offset speed reducer is approximately 95% at rated load. 
         [0057]    Use of the offset speed reducer and electric motors enables use of high speed, light weight electric motors which are smaller in diameter and output less torque than slower, heavier larger motors whether they are alternating current motors or direct current motors. The savings in space, weight and money attained by use of the offset planetary gear reducers with high speed motors is considerable. Use of planetary gear reducers provides a stable transmission of power with torque amplification inversely proportional to the speed reduction. The planetary gear reducers of the instant invention weigh approximately 100 pounds but can vary in weight depending on the materials used such as steel, stainless steel or aluminum. The gears  223 ,  225 ,  226 ,  229  and the carrier  230  are made of steel or stainless steel. Aluminum may be used for the gearbox casing  203 ,  203 A if extremely light weight is desired. The low weight of the gear reducer having a volume of about 300 cubic inches (approx. 8 inches in diameter and 5.5 inches deep) in combination with a light-weight alternating current motor provides a compact low cost arrangement when placed side by side as illustrated in  FIG. 2 . 
         [0058]    Alternating current electric motors  203 ,  204  are water cooled motors and run at 7,000 to 8,000 RPM. At approximately 7500 RPM the three phase electric motor outputs approximately 14.75 ft-lbs. of torque which equates to approximately 21 horsepower. The peak starting torque is about 77 ft-lbs. The motors to be used are about 14 inches long and 8 inches in diameter and have a volume of approximately 700 cubic inches. 
         [0059]      FIG. 2C  is an exploded view  200 C of the input to the gear reducer  221 T, the gear reducer  203 , and the output shaft  208 . Referring to  FIGS. 2B and 2C , sun pinion  227  is supported by bearing  223 B and  227 B. Use of gear  223  enables the planetary gear reducer to be offset as it is driven by pinion  221  which is on the shaft  221 S of the electric motor. Three planet gears  225 ,  226  and  229  and, more specifically, their teeth  225 T,  226 T and  229 T intermesh with sun pinion teeth  227 T and ring gear  234  and its teeth  234 T. 
         [0060]    Planet gears  225 ,  226  and  229  are supported by bearings (i.e.,  235 B) and are pinned to the carrier by pins. See, for example, pin  235  in  FIGS. 2A and 2B . Pin  225  P restrains pin  235  from movement within the carrier  230  and thus secures gear  225  in place. Gear  225  and the other planet gears are, of course, free to rotate but they are securely fastened to the carrier and impart rotational motion to the carrier  230 . Reference numeral  225 A indicates intermeshing between planet gear teeth  225 T and ring gear teeth  224 T. Referring to  FIG. 2A , output shaft  208  is supported by bearings  208 B and  208 C and intermeshes its spline  208 T with spline  230 T of the carrier. 
         [0061]    Planetary gear reducer  203  distributes the load evenly to three planets,  225 ,  226  and  229 . As previously indicated any reasonable number of planet gears from 1 to “n” may be used. Reciting the operation of the gear reducer, torque is applied by shaft  221 S through teeth  221 T of pinion  221  which imparts rotational movement and torque to gear  223 . Gear  223  includes sun pinion  227  which by and through its teeth  227 T imparts rotational movement and torque to gears  225 ,  226  and  229  via teeth  225 T,  226 T and  229 T. As previously stated planet gears  225 ,  226  and  229  are free to rotate and impart rotational movement to carrier  230  effecting a speed reduction which is transmitted to output shaft  208  which is interconnected with the carrier spline  230 T. The gearbox  203 ,  203 A is separable into two portions  203  and  203 A and they trap ring gear  224  when the gearbox is secured by fastener  240 A to the electric motor  201  and when the portions  203 ,  203 A are secured together by fastener  240 . 
         [0062]      FIG. 2D  is a perspective view  200 D of the carrier  203 ,  203 A, planet gears  229  and  225 , and output shaft  208  with a corresponding spline  208 T.  FIG. 2E  is a perspective view  200 E of the offset planetary gear reducer without bearing  208 B illustrated therein. The principal dimensions of the offset planetary gear reducer are approximately 8 inches in diameter and 5.5 inches deep neglecting the input housing  241  which houses pinion  221 . The offset planetary gear reducer is generally cylindrically shaped and includes a housing  241  for the shaft driven pinion gear  221 . A flange (unnumbered) is fastened to the motor  201 . 
         [0063]      FIG. 3  is a block diagram  300  illustrating a method for using high-speed electric motors in combination with offset planetary gear reducers in a utility vehicle. The first step includes orienting two high speed electric motors having shaft driven pinion gears side by side  301  such that their shaft driven pinion gears are arranged on opposite sides of the vehicle. Next, the method includes mounting offset planetary gear reducers in engagement with the shaft driven pinion gears  302 . Each of the planetary gear reducers  203 ,  204  include a gear driven by the shaft driven pinion gears  221 ,  222 . The gear driven by the shaft driven pinion gears includes a shaft portion formed as a sun pinion gear  227  which drives a planetary gear set and carrier  230  reacting against a ring gear  224  in the casing of the planetary gear reducer  203 ,  203 A. The carrier  230  of the planetary gear reducer includes a splined output  230 T and each of the splined outputs  230 T are on the same axis. The method further includes driving an output shaft  208 ,  214  coupled to the splined output  230 T of the planetary gear reducer. Finally, the method includes driving, with chains ( 209 ,  211 ,  213 ,  215 ), the wheel shafts ( 210 ,  212 ,  216 ,  217 ) of the vehicle. 
         [0064]    A list of reference numerals follows. 
       REFERENCE NUMERALS 
       [0000]    
       
           14   a - d -tires of vehicle 
           28 -battery 
           60 ,  64 -motor 
           62 ,  66 -sides of vehicle 
           68 ,  84 -coupling 
           70 ,  82 -spur gear reduction assembly 
           72 ,  86 -chain 
           74 ,  76 ,  88 ,  90 -gears 
           78 ,  80 ,  92 ,  94 -axles 
           70 ,  82 -spur gear reduction assembly 
           100 -prior art utility vehicle 
           200 -utility vehicle 
           200 A-enlarged portion of utility vehicle 
           200 B-further enlargement of planetary gear reducer 
           200 C-exploded view of powertrain 
           200 D-perspective exploded view of carrier and output shaft 
           200 E-perspective view of offset planetary gear reducer 
           201 ,  202 -alternating current motor 
           203 ,  203 A,  204 -gearbox 
           205 ,  206 -vehicle side wall 
           208 ,  214 -output shafts 
           208 B,  223 B,  227 B,  235 B,  208 C-bearing 
           208 T-spline on output shaft 
           209 ,  211 ,  213 ,  215 -drive chains 
           210 ,  212 ,  216 ,  217 -wheel shaft 
           210 A,  212 A,  216 A,  217 A-wheel tire 
           221 T-pinion teeth 
           221 ,  222 -motor shaft pinion gear 
           221 H-helical pinion 
           221 S,  222 S-motor shaft 
           223 -gear 
           223 H-helical gear 
           223 B-bearing 
           223 T-teeth on gear 
           224 -stationary ring gear 
           224 T-ring gear teeth 
           224 S,  259 S-seal 
           225 ,  226 ,  229 -planet gear 
           225 A-mesh between planet gear teeth  223 T and ring gear teeth  224 T 
           225 P-pin 
           225 T,  226 T,  229 T-planet gear teeth 
           227 -sun pinion 
           227 T-sun gear teeth 
           230 -carrier 
           230 T-spline on carrier 
           235 -pin 
           240 ,  240 A-bolt 
           241 -pinion housing 
           250 ,  251 -frame member 
           300 -block diagram of method of using high speed motor and offset planetary gear reducers 
           301 -orienting and mounting high speed motors side by side with pinions oppositely arranged 
           302 -mounting offset planetary gear reducer in engagement with the shaft driven pinion gears  303 -coupling an output shaft to the spined output at a desired rate  304 -driving the wheel shifts of the vehicle 
       
     
         [0117]    The invention has been set forth by way of example with particularity. 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 claimed invention.

Technology Classification (CPC): 8