Patent Publication Number: US-2019184822-A1

Title: Drive Configuration for Vehicle

Description:
CROSS-REFERENCE 
     This application claims the benefit of and priority to U.S. provisional application 62/607,173, titled “Drive Configuration for Vehicle”, filed Dec. 18, 2017, the contents of which are incorporated by reference herein. This application also incorporates by reference the subject matter of applications Ser. Nos. 15/244,793, 62/208,805, and 15/811,011, each titled, “Off-Road Vehicle”; the contents of each of which are herein incorporated by reference. 
    
    
     BACKGROUND 
     Some off-road vehicles include a chassis, an engine, a transmission, a front drive system connected to front ground engaging members and a rear drive system connected to rear ground engaging members. Mechanical power developed by the engine is communicated to the ground engaging members through the front drive system and the rear drive system. The transmission, such as a transaxle, is located rear of the engine. The transaxle is connected to the wheels associated with the ground engaging members via a constant velocity (CV) joint that allows the wheels to “travel” relative to the vehicle frame while still providing motive force to the wheels. 
     SUMMARY 
     According to some embodiments, an off-road vehicle includes a frame, an engine, a rear ground engaging member and first and second rear trailing arms. Each of the trailing arms have at least one housing and wherein, within each housing is a drive belt, the drive belt drivingly coupled to the engine and the rear ground engaging member. 
     According to some embodiments, an off-road vehicle includes a frame, an engine, a ground engaging member, a first trailing arm and a second trailing arm. Each of the trailing arms have at least one housing and wherein, within each housing is a drive belt, the drive belt drivingly coupled to the engine and a rear ground engaging member. 
     According to some embodiments, a trailing arm is drivingly coupled to a ground engaging member. The trailing arm includes, at least one housing member, a drive member coupled to receive mechanical power, a drive belt, and a driven member drivingly coupled to the drive member via the belt. The drive member, the belt and the driven member are housed within the at least one housing member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of an off-road vehicle having a trailing arm suspension according to some embodiments. 
         FIG. 2  is a side view of an off-road vehicle having a trailing arm suspension according to some embodiments. 
         FIG. 3  is a rear view of an off-road vehicle having a trailing arm suspension according to some embodiments. 
         FIG. 4  is a top view of an off-road vehicle having a trailing arm suspension according to some embodiments. 
         FIG. 5  is an isometric view of an off-road vehicle with the trailing arm of the rear suspension shown as partially exploded. 
         FIG. 6  is an exploded view of the trailing arm of the rear suspension according to some embodiments. 
         FIG. 7  is an exploded view of the rear suspension according to some embodiments. 
         FIG. 8  is an isometric view of the engine and transmission according to some embodiments. 
         FIG. 9  is a top view of an off-road vehicle having front and rear trailing arm suspensions according to some embodiments. 
         FIG. 10  is an isometric view of an off-road vehicle having front and rear trailing arm suspensions according to some embodiments. 
         FIG. 11  is an exploded view of the rear suspension according to some embodiments. 
         FIG. 12  is a side view of the off-road vehicle utilizing a trailing arm suspension in both the rear and front drive systems according to some embodiments. 
         FIG. 13  is a rear view of the off-road vehicle according to some embodiments. 
         FIG. 14  is an isometric view of a rear suspension and drive system according to some embodiments. 
         FIG. 15  is a top view of a rear suspension and drive system according to some embodiments. 
         FIG. 16  is a front view of a rear suspension and drive system according to some embodiments. 
         FIG. 17  is a side view of a rear suspension and drive system according to some embodiments. 
         FIG. 18  is a rear view of a rear suspension and drive system according to some embodiments. 
     
    
    
     In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in difference views. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
     DETAILED DESCRIPTION 
     In some embodiments, this application discloses a suspension that includes a trailing arm that incorporates a drive belt to drivingly couple the engine to the ground engaging member. In some embodiments, the trailing arm pivots about a first end, wherein the pivot axis of the trailing arm is close in proximity to the connection of the half-axle with the trailing arm. 
     Referring now to  FIGS. 1-8 , an off-road vehicle  10  comprises a frame  12 , an engine  14 , and one or more ground engaging members  16 . In some embodiments the frame  12  includes a front sub-frame  62 , a rear sub-frame  64  and a roll-over protection system (ROPS)  66 . The frame  12  includes a plurality of members connected to one another for example by bolts, fasteners, or weldments. The rear sub-frame  64  supports the engine  14  and a transmission  18  (e.g., transaxle). In some embodiments, the transmission  18  is coupled to the engine  14  via a continuously variable transmission. In some embodiments (shown in  FIGS. 1, 2 and 4 ) the transmission  18  is located forward of the engine  14 . In other embodiments (not shown), the transmission  18  may be located rearward of the engine  12 . In some embodiments, one or more half-shafts  20  extend laterally from transmission  18  and include a constant velocity (CV) joint  74  that drivingly couples the transmission  18  to first and second trailing arms  24 . As discussed in more detail with respect to  FIGS. 5-7 , the trailing arm  24  is utilized to drivingly couple the transmission  18  to the ground-engaging member  16 . In some embodiments, the vehicle  10  includes a front suspension (not shown) and a rear suspension  22 , including or more springs/shocks. In some embodiments, only the rear suspension  22  utilizes a trailing arm to drivingly couple the ground engaging members  16 , while in other embodiments only the front suspension utilizes a trailing arm to drivingly couple the trnamission  18  to the front ground engaging members  16 ; in some embodiments trailing arms are utilized to drivingly couple the transmission to both the front and rear ground engagine members (as shown in  FIGS. 9-13 ). In some embodiments, a shock/spring  26  (e.g., coil-over) extends from the trailing arm  24  to a portion of the frame  12 , such as first shock mount  28  located on cross-member  70 . 
     In some embodiments, trailing arm  24  includes a forward portion that is pivotally attached to the frame  12  of the vehicle and a rearward portion that is affixed to the ground engaging member  16 . For example,  FIGS. 1, 2, and 5  illustrate the pivot axis xi associated with the trailing arms  24 . In some embodiments, trailing arm  24  is coupled to half-shaft  20  and CV joint  74  at a location that is close to or coaxial with pivot axis x 1 . Trailing arm  24  includes a drive belt (or chain)  50  that drivingly couples the engine  14  to the rear ground engaging members  16 , for example via transmission  18 . The rear suspension  22 , including the trailing arm  24 , allows ground engaging member  16  to “travel” vertically in response to the terrain (e.g., bumps, holes) and/or changes in force applied (e.g., passengers getting in and out of the vehicle), wherein trailing arm  24  pivots about axis x 1  (shown in  FIGS. 2 and 4 ). As a result, the rearward portion of trailing arm  24  as well as ground engaging member  16  travel vertically (and slightly horizontally) along an arc path a 1  shown in  FIG. 2  (it should be noted, the arc path a 1  shown in  FIG. 2  is approximated in order to illustrate the direction taken by ground engaging members during travel of the rear suspension). In some embodiments, a benefit of driving the transmission  18  and wheel engagine member  16  via trailing arm  24  is that the horizontal forces generated as a result of travel of the ground engaging member  16  reduce “tire scrub”, which is defined generally as the lateral travel of the ground engaging member  16  (i.e., perpendicular to the forward direction of the vehicle) that occurs when the tire travels vertically as the rear suspension  22  is compressed/uncompressed. In some embodiments, a benefit of trailing arm  24  is the ability to increase the amount of travel available to rear suspension  22  and ground engaging members  16  when compared to typical arrangemnets while reducing/eliminating tire scrub. By way of example, the tire in suspension shown in U.S. Pat. No. 8,764,039, undergoues tire scrub (as defined herein) as the suspension compresses—the tire moves laterally, and follows an arc determined by the CV shaft and lateral links  150 . In contrast, the trailing arm  24  disclosed herein need not move laterally as the suspension is compressed/extended and tire scrub can be reduced or eliminated. In some embodiments, another benefit of drivingly coupling engine  14  to ground engagine members  16  via trailing arm  24  is that movement and plunging of the CV joint  74  shown in  FIG. 6  is reduced or eliminated by locating the pivot axis x 1  of trailing arm  24  in close proximity to the connection of rear half-shaft  20  to the trailing arm  24 . 
     Referring specifically to  FIGS. 5-7  the trailing arm assembly  24  is described in more detail. In some embodiments, trailing arm assembly  24  comprises one or more housings, such as a first housing  30  and a second housing  32 , first trailing arm support  36 , second trailing arm support  40 , driving member  46 , driven member  48 , and belt/chain  50 . 
     In some embodiments, one or both of the first and second housings  30 ,  32  include a second shock mount  34 . As shown in  FIG. 5 , in some embodiments, a portion of the second shock mount  34  is coupled to the first housing  30  and a second portion of the second shock mount  34  is coupled to the second housing  32 . The shock mount  34  can be formed integrally with the housing(s)  30 ,  32  or it can be attached thereto, for example by one or more fasteners. In some embodiments, the shock/spring  26  is connected between shock mount  34  and shock mount  28 . 
     In some embodiments, the first housing  30  and the second housing  32  are fastened together, forming an enclosure that protects the driving member  46 , the driven member  48  and belt/chain  50  from exterior elements. In some embodiments, first housing  30  and second housing  32  may form a seal when first housing  30  is brought into contact with second housing  32 . In some embodiments, second housing  32  includes an aperture  80  (shown in  FIG. 7 ) for receiving the splined portion  76  (shown in  FIG. 6 ) of half-shaft  20 , and the first housing  30  includes an aperture  82  for receiving a splined portion (not shown) for connecting the driven member  48  to the wheel hub  52 , which in turn is connected to the ground engaging member  16 . In some embodiments, transmission  18  is drivingly coupled to drive member  46  via rear half-shafts  20 , CV joint  74 , and spline  76 . In turn, drive member  46  is drivingly coupled to driven member  48  via the belt  50 . While a belt is utilized in the embodiment shown in  FIGS. 5-8 , in other embodiments a chain may be utilized to drivingly couple drive member  46  and driven member  48 . In some embodiments, first and second trailing arm support hubs  38 ,  100  are fastened to first and second housing members  30 ,  32 , respectively such that the assembly (including trailing arm support hub  38 , first housing  30 , second housing  32 , first trailing arm support  36 , and second trailing arm support  40 ) pivot together about the pivot axis x 1  as the suspension is compressed/uncompressed through its range of travel. In the embodiment shown in  FIGS. 5-7 , driven member  48  is located rearward of drive member  46  as trailing arm  24  is connected to rear ground engagine members  16 . In other embodiments, trailing arm  24  could be utilized in combination with the front suspension in which driven member  48  would be located forward of drive member  46 . In some embodiments, the transmission  18  further includes an output shaft  54  ( FIG. 6 ) that can be used to provide power to a front differential to drive front ground engaging members (not shown). 
     In some embodiments, half-shaft  20  is coupled to drive member  46  (in the housing of trailing arm  24 ) at a location that is close to or or along the pivot axis of trailing arm  24  (illustrated by axis x 1 ). In some embodiments, the half-shaft  20  is coupled to the drive member  46  at a distance d 1  ( FIG. 2 ) that is less than 12″ and, in some embodiments, less than 10″, 8″, or less than 5″. A benefit of coupling the half-shaft  20  to the trailing arm  24  at or near the pivot point of trailing arm  24  is that the travel of rear suspension  22  is allowed to be large without having a large plunge associated with half-shaft  20  or CV joint  74  (as discussed in U.S. Publication No. 2017/0248169) and further without excessive (or any) tire scrub, as discussed above. 
     In some embodiments, first trailing arm support  36  and second trailing arm support  40  are coupled to the first and second housing members  30  and  32 , respectivley, to provide additional support. In some embodiments, first trailing arm support  36  includes a first end  84  and a second end  86 . First trailing arm support is affixed to first housing  30  at a first end  84  and to arm support hub  38  on the second end  86 . In some embodiment, first trailing arm support  36  is fastened to first housing  30  via one or more fasteners. Second trailing arm support  40  likewise includes a first end  94  and a second end  96 , wherein the second trailing arm support  40  is affixed to the second housing  32  at a first end  94  and to a second arm support hub  100  (shown in  FIG. 8 , on the right-hand side of the vehicle) on a second end  96 . In some embodiments, first trailing arm support  36  and second trailing arm support  40  are allowed to pivot, along with support hub  38 , around an axis defined on second end  86  and second end  96 , respectively. In some embodiments, this axis is along axis x 1 . The first trailing arm support  36  and second trailing arm support  40  thereby pivot in response to travel of ground engaging member  16  along the arc path a 1  shown in  FIG. 2 , for example. 
     In some embodiments, first and second arm support hubs  38  and  100 , respectively, are rigidly secured to the frame  12  and provide a ledge  98  (shown with respect to first arm support hub  38 ) that supports first housing member  30 , wherein a ledge associated with second arm support hub  100  would provide support to second housing member  32 . As discussed above, however, in some embodiments, the first and second arm support hubs  38  and  100  pivot with the first and second housing members  30 ,  32 . In some embodiments, first housing member and second housing member  30 ,  32  are allowed to pivot within first and second arm support hubs  38  and  100  to accomodate travel of the ground engaging member  16 . 
     Rear suspension  22  includes a trailing arm  24  having a first end and a second end, wherein the first end is drivingly coupled to the transmission  18  and the second end is drivingly coupled to the ground engaging member  16 . Trailing arm  24  is allowed to pivot about an axis x 1  located on the first end, such that the ground engaging member  16  is allowed to travel. As discussed above, a benefit of drivingly coupling the ground engaging member  16  to the transmission  18  via the trailing arm  24  is that the arc path taken by the ground engaging member  16  reduces or eliminates tire scrub. In particular, the horizontal component of the arc path is in the direction of travel of the ground engaging member  16 . 
     As discussed above, the same concept described with respect to the rear supsension shown in  FIGS. 5-7  may be utilized with respect to the front suspension and drive system as well. For example, in the embodiment shown in  FIG. 8 , the transaxle  104  is coupled to engine  14  via continuously variable transmission (CVT)  102 . Transaxle  104  provides power to the rear ground engaging members as described above with respect to  FIGS. 5-7 . In addition, in some embodiments, transaxle  104  is drivingly coupled to front drive  58  via main drive belt  56 . In some embodiments, the front drive can be a front differential that is driven by a shaft or main drive belt  56 , as desired. In some embodiments, the front drive  58  can be used in conjunction with front trailing arms  106  coupled to the front ground engaging members as previously described. 
     Referring now to  FIGS. 9-13 , an all-terrain vehicle (ATV)  110  is shown that utilizes front trailing arms  112  and rear trailing arms  114 . In some embodiments, ATV  110  includes a straddle-seat  118 , handlebars  120 , wheels  122 , frame  124 , engine  126 . In some embodiments, front wheels  122  are drivingly coupled to a front drive system (not shown) via front trailing arms  112 . In some embodiments, rear wheels  122  are drivingly coupled to a rear drive system (not shown) via rear trailing arms  114 . In some embodiments, both trailing arms are utilized for both front wheels  122  and back wheels  122 . 
     Referring in particular to  FIG. 11 , the front trailing arm  112  is shown connected to front wheel  122 . In some embodiments, front trailing arm  112  includes first housing member  130  and second housing member  132 , support members  134 , and control arms  136 . A front drive (not shown in this view) is drivingly coupled to front wheel  122  via a drive belt housed within front trailing arm  112 . In some embodiments, front trailing arm  112  further includes a drive member and driven member drivingly coupled to one another via the belt, wherein the driven member is drivingly coupled to the wheel  122 . First trailing arm  112  pivots about axis x 2 , which causes wheel  122  to travel along an arc path shown by dashed line a 2 . As described with respect to rear trailing arms  24 , the front trailing arms  106  move along a path a 2 , thereby reducing or eliminating tire scrub during travel of the front engaging member  16 . In contrast, a typical front suspension accomodates travel of the front wheel via a constant velocity (CV) joint that results in horizontal force applied in a lateral direction. The front trailng arm  106  pivots about a lateral axis which results in a travel arc that has a horizontal component in the direction of travel of the vehicle (e.g., forward, backward). 
     Although not shown in  FIGS. 9-13 , in some embodiments, a front drive system is connected to front trailing arm  112  along axis x 2 . In some embodiments, the front drive system includes a front differential coupled to the front trailing arm  112  via a CV joint and drive sprocket. A drive element (not shown) located within the first housing member  130  and second housing member  132  is coupled to the drive sprocket to receive rotational power from the front drive system. As discussed above with respect to  FIGS. 5-8 , the drive element is drivingly coupled via a belt or chain to a driven element, which in turn is coupled to shaft  142 . As shown in  FIG. 11 , splined shaft  142  is coupled to wheel hub  140 , which in turn is affixed to wheel  122 . 
     In the embodiment shown in  FIGS. 11 and 12 , control arms  136  are coupled through mechanical linkages to handlebars  120 , allowing a driver to turn front wheels  122 . Support  134  is coupled between front trailing arm  112  and frame  124 . In some embodiments, support  134  includes a shock/spring system that allows vertical travel of wheels  122 . In some embodiments, one or more trailing arm supports may also be affixed between first housing member  130 , second housing member  132  and frame  124 . In some embodiments, such as that shown in  FIG. 11 , the housing members include integrally formed supports such as support  144  integrated with second housing member  132 . 
     As described with respect to off-vehicle  10  shown in  FIGS. 1-8 , drivingly coupling the front and/or rear wheels to the engine via front and/or rear trailing arms increases the front and/or rear suspension travel lengths as compared to known vehicle suspensions. In some embodiments, this is due, at least in part, to the half-shafts  20  providing power to respective ground engaging members  16  at or near the pivots of the trailing arms. In prior art designs, such as that shown in U.S. Pat. No. 8,746,719, the ground engaging members experience scrub as the suspension moves through its travel. Further, when looking forwardly at the vehicle from the rear of the vehicle, the knuckle shown in swings an arc as the suspension moves through its range of travel. And, the half-shaft associated with the suspension shown in experiences a minimal amount of plunge (e.g., less than 1″), due to the knuckle moving in an arc when viewed from the rear of the vehicle. This, however, can limit the suspension travel for a given-width vehicle. In contrast, however, the vehicle and suspension shown herein can have a greater degree of suspension travel, as the half-shafts  20  are located at or near the pivots of the trailing arms  24 . In this way, the half-shafts  20  neither trace a large arc nor have a large degree of plunge. 
     Referring now to  FIGS. 14-18  a rear suspension and drive system is shown. The rear supsension and drive system includes primary drive chain/belt  158 , ground engaging member  160 , trailing arm  162 , which includes drive member  164 , driven member  166 , belt/chain  168 , and shaft  169 , first support arm  170 , spring/shock  172 , wheel hub housing  174 , shaft  176 , trailing arm pivot  178 , second support arm  180 , second bearing/bushing  182 , third bearing/bushing  184 , brake caliper  186 , and primary sprocket and brake disc  188 . In this embodiments, the right side (far side in  FIG. 14A ) shows a belt  168 . The left side (near side in  FIG. 14A ) shows the drive member  164  and driven member  166  with the belt  168  removed for clarity. 
     In some embodiments, primary drive chain/belt  158  is drivingly coupled to shaft  176 , which in turn is connected to drive members  164 . In some embodiments, the shaft  176  is supported by a bearings  182  and  184 . In some embodiments, a bushing may be utilized in place of bearings for one or both of bearings  182  and  184 . Drive member  164  is secured to shaft  176  and drivingly coupled to driven member  166  via belt  168 . Driven member  166  is coupled to wheel hub housing  174  via shaft  169 , which in turn is drivintly connected to ground engaging member  160 . In some embodiments, one or more housing members enclose drive member  164 , driven member  166  and belt  168 . 
     In some embodiments, one or more trailing arm support members  170 ,  180  are coupled to the wheel hub housing  174  to provide additional support. In some embodiments, first trailing arm support member  170  is coupled on one end to bearings  182  and on an opposite end to wheel hub housing  174 . In some embodiments, bearings  182  are affixed to the frame (not shown) of the off-road vehicle. In some embodiments, second trailing arm support member  180  is coupled on one end to wheel hub housing  174  and on an opposite end to trailing arm pivot  178 . In some embodiments, second trailing arm support member  180  is a tube. 
     In some embodiments, spring/shock  172  is connected between the frame (not shown) and one or more of trailing arm support member  170  and/or  180 . For example, in the embodiment shown in  FIG. 16 , the spring/shock  172  is affixed via fasteners to second trailing arm support member  180 . In some embodiments, such as that shown in  FIG. 15 , spring/shock  172  is fastened to second trailing arm support member  180  and to first trailing arm support member  170 . 
     In some embodiments, the rear suspension including the trailing arm  162 , allows ground engaging members  160  to “travel” vertically in response to the terrain (e.g., bumps, holes) and/or changes in force applied (e.g., passengers getting in and out of the vehicle), wherein trailing arm  162  pivots about axis x 3  (shown in  FIGS. 15 and 17 ). As a result, the rearward portion of trailing arm  162  as well as ground engaging member  160  travel vertically (and slightly horizontally) along an arc path a 3  shown in  FIG. 17  (it should be noted, the arc path a 3  shown in  FIG. 17  is approximated in order to illustrate the direction taken by ground engaging members during travel of the rear suspension). 
     In this way, the disclosed invention provides a suspension that utilizes a trailing arm to couple the drive system to the ground engaging members.