Abstract:
The present concept is a support arm which connects a drive shaft to a driven shaft, the support arm includes a drive arm includes at one end a drive bearing connected to a drive shaft and the other connecting end is attached to an arm connector. It further includes a driven arm which includes at one end a driven bearing connected to a driven shaft and the other connecting end is attached to the arm connector. The arm connector includes adjusting means for adjustably attaching the driven arm to the arm connector.

Description:
[0001]    This application claims priority from prior provisional application No. 61/903,617, filed on Nov. 13, 2013 by Shawn Watling under title: SNOW MOBILE DRIVE ASSEMBLY 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present concept relates to drive trains used in snow mobiles and other vehicles which are powered by small engines such as all terrain vehicles (ATV&#39;s) and golf carts and more particularly relates to stiffening of the primary drive assembly. 
       BACKGROUND OF THE INVENTION 
       [0003]    Presently drive trains for snow mobiles, ATV&#39;s and other small vehicles such as golf carts normally include a drive primary clutch which is connected to the output shaft of a motor and a driven secondary clutch which further transmits power to the drive line of the vehicle. 
         [0004]    U.S. Pat. No. 6,561,302 issued on May 13, 2013 and invented by Mr Gerrard Karpik under the title Snowmobile Construction describes a snowmobile drive train and particularly describes the use of a torque arm  310  which is depicted in  FIG. 14  of the patent specification. The specification acknowledges that there is an incredible amount of force generated by the drive belt in the drive assembly. In order for the drive belt to be effective it must be placed under tension between the drive pulley and the driven pulley. U.S. Pat. No. 6,561,302 describe the use of a torque arm which is denoted as  310  in the specification to counteract the opposing forces generated by the drive belt as described in column 10 lines 47 to 55 of the specification. 
         [0005]    It is known that the stress imparted by the motor can exceed 2100 lbs of tensile load on the drive belt and these tensions must be accommodated by both the drive pulley and the driven pulley without failing. 
         [0006]    Modern day snow mobiles, ATV&#39;s and other small engine vehicles create so much power that incredible amounts of torque and horse power are transmitted through the drive and driven pulleys so much so that engine torque pulses are transmitted through the drive and driven pulleys to the chassis which results in a significant amount of vibration through the entire chassis of the vehicle. The vibration is so large that there have been reports of the drivers indicating that their hands have become numb due to the vibration transmitted from the drive line through the chassis and up through the handlebars and into the hands of the driver gripping the handlebars. 
         [0007]    Therefore there is a need for a mechanism to control and dampen the torque pulsing and vibrations that are increasingly being observed in snowmobiles ATV&#39;s and other small engine vehicles due to the increasing amounts of horse power and torque transmitted through their drivelines. 
       SUMMARY 
       [0008]    The present concept a support arm connecting a drive shaft to a driven shaft, the support arm includes: 
         [0009]    a) a drive arm which includes at one end a drive bearing connected to a drive shaft and the other connecting end is attached to an arm connector, 
         [0010]    b) a driven arm  118  which includes at one end a driven bearing connected to a driven shaft and the other connecting end is attached to the arm connector, 
         [0011]    c) wherein the arm connector includes adjusting means for adjustably attaching the driven arm to the arm connector. 
         [0012]    Preferably wherein the arm connector includes a back side for receiving thereon the connecting end of the driven arm. 
         [0013]    Preferably wherein the adjusting means includes an outer rail and an inner rail for sandwiching there between with rail bolts the connecting end of driven arm and the back side of the arm connector. 
         [0014]    Preferably wherein the connecting end of the driven arm includes adjusting slots wherein the rail bolts pass through the adjusting slots. 
         [0015]    Preferably wherein the rails are u shaped rails. 
         [0016]    Preferably wherein the arm connector includes a central box section which includes a top side, a bottom side, a front side and a back side. 
         [0017]    Preferably wherein the back side for receiving thereon the connecting end of the driven arm. 
         [0018]    Preferably wherein the adjusting means includes an outer rail and an inner rail for sandwiching there between with rail bolts the connecting end of driven arm and the back side of the arm connector. 
         [0019]    Preferably wherein the connecting end of the driven arm includes adjusting slots wherein the rail bolts pass through the adjusting slots. 
         [0020]    Preferably wherein the rails are u shaped rails. 
         [0021]    Preferably wherein the front side for receiving thereon the connecting end of the drive arm. 
         [0022]    Preferably wherein the connecting end of the drive arm connected to the front side of the arm connector with nuts and bolts which pass through drive arm holes and front holes. 
         [0023]    Preferably wherein there are a number of front holes and corresponding drive arm holes which can be used to selectively adjust the length of the support arm. 
         [0024]    Preferably wherein the drive arm includes a drive bearing housing for receiving the drive bearing therein and a drive bearing retainer for clamping the drive bearing in the drive bearing housing. 
         [0025]    Preferably wherein the driven arm includes a drivenbearing housing for receiving the driven bearing therein and a driven bearing retainer for clamping the driven bearing in the driven bearing housing. 
         [0026]    Preferably further including a drive retaining bolt for retaining the drive bearing onto the drive shaft. 
         [0027]    Preferably further including a driven retaining bolt for retaining the driven bearing onto the driven shaft. 
         [0028]    Preferably further including drive bearing support bushing for receiving the drive bearing on one end and connecting to the drive shaft on the other end. 
         [0029]    Preferably further including driven bearing support bushing for receiving the driven bearing on one end and connecting to the driven shaft on the other end. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The present concept will now be described by example only with reference to the following drawings in which: 
           [0031]      FIG. 1  is a side schematic exploded perspective assembly view of a portion of a snowmobile drive assembly showing the assembly of the primary clutch and the secondary clutch, together with a support arm. 
           [0032]      FIG. 2  is a side schematic exploded perspective assembly view of the support arm. 
           [0033]      FIG. 3  is a side schematic exploded perspective view of a portion of a snow mobile drive assembly showing the assembly of the primary clutch and secondary clutch together with a support arm for an original equipment installation. 
           [0034]      FIG. 4  is a side schematic perspective assembly view of the support arm together with the primary clutch and secondary clutch and a motor showing the motor connected to the drive shaft and the primary clutch and the output through to the driven shaft. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0035]    The present concept a snow mobile drive assembly is shown generally as  100  includes an input end  102  which receives power from the motor shaft and transmits this power to a drive pulley  106  which in turn drives drive belt  108  thereby transmitting power to the output end  104  which includes a driven pulley  110  being driven by drive belt  108 . 
         [0036]    Input end  102  normally includes a primary clutch  112  and output end  104  normally includes a secondary clutch  114 . 
         [0037]    A very high amount of tension on drive belt  108  causes engine torque pulses and vibrations to be transmitted between drive pulley  106  and driven pulley  110  and through the shaft that is supporting these pulleys. Tension of up to 2100 lbs of load is being transmitted through drive belt  108  due to the great amount of power created by the motor. 
         [0038]    The reader will note that the motor is not shown in  FIG. 1  however the output shaft of the motor connects directly to drive pulley  106  at the input end  102 . 
         [0039]    In order to control the engine torque pulses and vibrations created by the large amount of power being transmitted through drive assembly  100  a support arm  106  has been developed and is connected to the drive assembly  100  as depicted in  FIG. 1 . 
         [0040]    Support arm  106  preferably is a two part arm which includes a drive arm  116  and a driven arm  118 . Drive arm  116  includes an adjusting rail  120  and a lock nut  122  for adjusting the longitudinal length of support arm  106  and locking the length in place. 
         [0041]    At input end  102  support arm  106  includes a drive flange  124  with a drive bearing housing  126 . 
         [0042]    A drive bearing  128  is installed into drive bearing housing  126 . 
         [0043]    A drive bearing support bushing  130  is installed into primary clutch  142  in order to support drive bearing  128 . 
         [0044]    A drive retaining bolt  132  securely fastens drive flange  124  which includes drive bearing  128  and drive bearing support bushing  130  therein onto primary clutch  112 . 
         [0045]    Similarly driven arm  118  terminates at driven flange  140  which includes a driven bearing housing  142  for housing therein a driven bearing  144  which is supported by driven bearing support bushing  146 . 
         [0046]    Driven retaining bolt  148  securely attaches driven arm  118  which includes driven bearing  144  and driven bearing support bushing  146  onto secondary clutch  114 . The outside diameter  150  of drive bearing  128  and the outside diameter  152  of driven bearing  144  are spherical diameter bearings to allow for pivoting of the entire support arm  106 . 
         [0047]    In original equipment arrangements drive bearing  128  at input end  102  is connected and mounted onto drive shaft  252  directly as shown in  FIG. 3  eliminating the need for a drive bearing support bushing  130 . Similarly driven bearing  144  at output end  104  is connected and mounted driven shaft  250  shown in  FIG. 3  eliminating the need for a driven bearing support bushing  146 . Support bushings  130  and  146  are required to retrofit existing equipment. 
         [0048]    During hard acceleration the amount of tension on drive belt  108  is so great that it tends to cause bending of the motor output shaft and the crank shaft of the engine as well as the jack shaft at the driven pulley  110 . The support arm  106  minimizes this bending and avoids catastrophic failure of either breaking of the main motor output shaft and/or crank shaft and/or the jack shaft. 
         [0049]    The amount of bending and vibration that is being transmitted through the motor shaft connected to drive pulley  106  and a jack shaft which is normally connected to driven pulley  110  is so great that failure of either to motor shaft and/or the jack shaft has been observed in practice. 
         [0050]    Referring now to  FIG. 2  which shows in exploded perspective fashion a support arm  106  which includes the following components namely drive arm  116 , arm connector  212  and driven arm  118 . 
         [0051]    Arm connector  212  includes central box section which has a top side  214 , a bottom side  216  , a front side  218  having front holes  230  and a back side  234  which includes back holes  232 . 
         [0052]    Driven arm  118  includes a connecting end  272  with adjusting slots  246  which register with back holes  232  of back side  234  and are clamped together using inner rail  236  and outer rail  238  together with rail bolts  240  in order to clamp driven arm  118  onto back side  234  of arm connector  212 . 
         [0053]    Drive arm  116  includes a connecting end  270  which has drive arm holes  248  which register with front holes  230  in front side  218  of arm connector  212 . Bolts not shown are used to connect drive arm  116  to the front side of arm connector  212 . 
         [0054]    A drive bearing retainer  210  is used to mount drive bearing  128  into drive bearing housing  126  using retainer bolts  244 . Similarly driven bearing retainer  242  is used to retain driven bearing  144  in driven bearing housing  142  of drive arm  118 . 
         [0055]    Referring now to  FIG. 3  which is similar to  FIG. 1  except that it does not include drive bearing support bushing  130  and driven bearing support bushing  146  since  FIG. 3  shows an original equipment insulation. 
         [0056]    Instead in  FIG. 3  drive bearing  128  is mounted directly onto drive shaft  252  and driven bearing  144  is mounted directly onto driven shaft  250  and held in place with drive retaining bolt  132  and driven retaining bolt  148  as depicted in  FIG. 3 . In this manner one able to eliminate the adapters namely drive bearing support bushing  130  and driven bearing support bushing  146  which essentially adapt any existing drive arrangement for mounting of support arm  106  thereon. 
         [0057]    Finally  FIG. 4  shows in schematic fashion a drive assembly which includes a motor which drive a drive belt  108  via a primary clutch  112  and a secondary clutch  114  through a drive pulley  106  and a driven pulley  110 . 
         [0058]    Support arm  106  is shown assembled and bolted onto the primary clutch  112  on the drive end and onto secondary clutch  114  and driven pulley  110  on the driven end which outputs through driven shaft  250 . 
         [0059]    It should be apparent to persons skilled in the arts that various modifications and adaptation of this structure described above are possible without departure from the spirit of the invention the scope of which defined in the appended claim.