Patent Publication Number: US-10766568-B1

Title: Snowmobile

Description:
CROSS-REFERENCE 
     The present application is a continuation of U.S. patent application Ser. No. 16/404,831, filed on May 7, 2019, which is a continuation of U.S. patent application Ser. No. 16/029,278, filed on Jul. 6, 2018, which claims priority to U.S. Provisional Patent Application No. 62/529,244, filed on Jul. 6, 2017, the entirety of each of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to a snowmobile, and in particular to a configuration of its motor and transmission. 
     BACKGROUND 
     Snowmobiles are designed for travel over snow on a variety of terrains. However, due to its size, a snowmobile may be restricted from navigating areas where obstacles (e.g., vegetation) are dense. Notably, the snowmobile typically includes two laterally-spaced skis which impart a significant width to the snowmobile such that maneuvering between obstacles may be difficult. In order to address this, in some snowmobiles, the skis can be adjusted to be positioned closer to one another. Nevertheless, certain components of the snowmobile&#39;s powertrain may still impose a significant width to the snowmobile. 
     In some cases, a motorcycle may be adapted to travel over snow by replacing its front and rear wheels by a ski and a tracked suspension assembly respectively, thus resulting in a relatively narrow vehicle capable of travelling over snow. However, motorcycles are generally not optimized for winter use and may thus exhibit poor performance when modified as described. For example, due to the configuration of the motorcycle&#39;s powertrain (including, for example, its engine and transmission), the weight distributed on the ski and the tracked suspension assembly may not be optimal for travelling over snow. Furthermore, certain components, such as the motorcycle&#39;s transmission, may not be suited for interaction with snow. 
     For these and other reasons, there is a desire for modification to existing snowmobile designs. 
     SUMMARY 
     It is an object of the present invention to ameliorate at least some of the inconveniences described above. 
     In accordance with an aspect of the present technology, there is provided a snowmobile. The snowmobile includes: a frame; a ski connected to the frame; a seat connected to the frame for accommodating a driver of the snowmobile; a rear suspension assembly operatively connected to the frame; an endless track supported by the rear suspension assembly; a motor supported by the frame; and a continuously variable transmission (CVT) operatively connecting the motor to the endless track for driving the endless track. The rear suspension assembly includes: at least one slide rail; a suspension assembly drive axle defining a drive axle rotation axis; a drive sprocket mounted to the drive axle; and a plurality of idler wheels connected to the at least one slide rail. The drive sprocket of the rear suspension assembly is rotatable about the drive axle rotation axis to drive the endless track. The motor includes a shaft rotatable about a shaft rotation axis. The drive axle rotation axis is positioned forwardly of the shaft rotation axis of the shaft of the motor. The seat is positioned above the motor. 
     In some implementations, the CVT includes a primary pulley operatively connected to and driven by the motor, a secondary pulley operatively connected to and driven by the primary pulley, and a transmission belt connecting the primary pulley to the secondary pulley. The primary pulley is rotatable about a primary pulley rotation axis, the primary pulley rotation axis extending parallel to the shaft rotation axis of the shaft of the motor, the primary pulley being operatively connected to the shaft of the motor by one of a chain and a belt. The secondary pulley is rotatable about a secondary pulley rotation axis. The secondary pulley is operatively connected to the endless track to drive the endless track. 
     In some implementations, the snowmobile also includes: a primary pulley shaft defining the primary pulley rotation axis, the primary pulley being mounted to the primary pulley shaft to rotate therewith; and a secondary pulley shaft defining the secondary pulley rotation axis, the secondary pulley being mounted to the secondary pulley shaft to rotate therewith, the one of the chain and the belt being operatively connected between the primary pulley shaft and the shaft of the motor. 
     In some implementations, the primary and secondary pulley shafts are rotatably supported by the frame. 
     In some implementations, the primary pulley rotation axis extends laterally; and the primary pulley rotation axis is positioned forwardly of the shaft rotation axis of the shaft of the motor. 
     In some implementations, the secondary pulley rotation axis is positioned forwardly of the primary pulley rotation axis. 
     In some implementations, the secondary pulley is operatively connected to the drive sprocket of the rear suspension assembly by a link; and the primary and secondary pulleys of the CVT are disposed laterally between the link operatively connecting the secondary pulley to the drive sprocket and the one of the chain and the belt operatively connecting the primary pulley to the shaft of the motor. 
     In some implementations, the drive axle rotation axis is positioned rearwardly of the secondary pulley rotation axis. 
     In some implementations, the drive axle rotation axis is positioned rearwardly of the primary pulley rotation axis. 
     In some implementations, the secondary pulley rotation axis is vertically lower than the primary pulley rotation axis. 
     In some implementations, the ski is a single laterally centered ski. 
     In some implementations, the one of the chain and the belt is the chain. The snowmobile also includes: a first sprocket mounted to the shaft of the motor; and a second sprocket mounted to the primary pulley shaft. The chain is connected between the first and second sprockets to operatively connect the shaft of the motor to the primary pulley. 
     In some implementations, the second sprocket has a smaller diameter than the primary pulley. 
     In some implementations, the motor is an internal combustion engine, the shaft of the motor is a crankshaft and the shaft rotation axis of the shaft of the motor is a crankshaft rotation axis. 
     According to another aspect of the present technology, there is provided a snowmobile. The snowmobile includes: a frame; a ski connected to the frame; a seat connected to the frame for accommodating a driver of the snowmobile; a rear suspension assembly operatively connected to the frame; an endless track supported by the rear suspension assembly; a motor supported by the frame; and a continuously variable transmission (CVT) operatively connecting the motor to the endless track for driving the endless track. The rear suspension assembly includes: at least one slide rail; a suspension assembly drive axle defining a drive axle rotation axis; a drive sprocket mounted to the drive axle; and a plurality of idler wheels connected to the at least one slide rail. The drive sprocket of the rear suspension assembly is rotatable about the drive axle rotation axis to drive the endless track. The motor includes a shaft rotatable about a shaft rotation axis. The drive axle rotation axis is positioned forwardly of the shaft rotation axis of the shaft of the motor. The seat is positioned above the shaft rotation axis of the shaft of the motor. 
     In some implementations, the CVT includes a primary pulley operatively connected to and driven by the motor, a secondary pulley operatively connected to and driven by the primary pulley, and a transmission belt connecting the primary pulley to the secondary pulley. The primary pulley is rotatable about a primary pulley rotation axis, the primary pulley rotation axis extending parallel to the shaft rotation axis of the shaft of the motor, the primary pulley being operatively connected to the shaft of the motor by one of a chain and a belt. The secondary pulley is rotatable about a secondary pulley rotation axis. The secondary pulley is operatively connected to the endless track to drive the endless track. 
     According to another aspect of the present technology, there is provided a snowmobile. The snowmobile includes a frame; a ski connected to the frame; a seat connected to the frame for accommodating a driver of the snowmobile; a rear suspension assembly operatively connected to the frame; an endless track supported by the rear suspension assembly; an internal combustion engine supported by the frame; a continuously variable transmission (CVT) operatively connecting the engine to the endless track for driving the endless track; and a fuel tank supported by the frame and positioned rearwardly of the engine. The rear suspension assembly includes: at least one slide rail; a suspension assembly drive axle defining a drive axle rotation axis; a drive sprocket mounted to the drive axle; and a plurality of idler wheels connected to the at least one slide rail. The drive sprocket of the rear suspension assembly is rotatable about the drive axle rotation axis to drive the endless track. The engine includes a crankshaft rotatable about a crankshaft rotation axis. The drive axle rotation axis is positioned forwardly of the crankshaft rotation axis. 
     In some implementations, the fuel tank is positioned rearwardly of the seat. 
     In some implementations, the CVT includes a primary pulley operatively connected to and driven by the motor, a secondary pulley operatively connected to and driven by the primary pulley, and a transmission belt connecting the primary pulley to the secondary pulley. The primary pulley is rotatable about a primary pulley rotation axis, the primary pulley rotation axis extending parallel to the shaft rotation axis of the shaft of the motor, the primary pulley being operatively connected to the shaft of the motor by one of a chain and a belt. The secondary pulley is rotatable about a secondary pulley rotation axis. The secondary pulley is operatively connected to the endless track to drive the endless track. 
     In some implementations, the snowmobile also includes: a primary pulley shaft defining the primary pulley rotation axis, the primary pulley being mounted to the primary pulley shaft to rotate therewith; and a secondary pulley shaft defining the secondary pulley rotation axis, the secondary pulley being mounted to the secondary pulley shaft to rotate therewith, the one of the chain and the belt being operatively connected between the primary pulley shaft and the crankshaft. 
     For purposes of the present application, terms related to spatial orientation when referring to the snowmobile and components in relation to the snowmobile, such as “forward”, “rearward”, “left”, “right”, “above” and “below”, are as they would be understood by a driver of the snowmobile sitting thereon in a normal riding position, with the snowmobile in a straight ahead orientation (i.e. not steered left or right), and in an upright position (i.e. not tilted). When referring to a component alone, terms related to spatial orientation are described with respect to the component as disposed on the snowmobile. 
     Implementations of the present invention each have at least one of the above-mentioned object and/or aspects, but do not necessarily have all of them. It should be understood that some aspects of the present invention that have resulted from attempting to attain the above-mentioned object may not satisfy this object and/or may satisfy other objects not specifically recited herein. 
     Additional and/or alternative features, aspects, and advantages of implementations of the present invention will become apparent from the following description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the present invention, as well as other aspects and further features thereof, reference is made to the following description which is to be used in conjunction with the accompanying drawings, where: 
         FIG. 1  is a left side elevation view of a snowmobile; 
         FIG. 2  is a left side elevation view of the snowmobile of  FIG. 1  with certain components removed to expose part of a frame, an engine and a continuous variable transmission of the snowmobile; 
         FIG. 3  is a top plan view of the snowmobile as shown in  FIG. 2 ; 
         FIG. 4  is a front elevation view of the snowmobile as shown in  FIG. 2 ; 
         FIG. 5  is a rear elevation view of the snowmobile as shown in  FIG. 2 ; 
         FIGS. 6 and 7  are top and bottom plan views of a portion of the snowmobile of  FIG. 1  showing an exhaust system of the snowmobile; 
         FIG. 8  is a top plan view of the portion of the snowmobile shown in  FIGS. 6 and 7  with an exhaust pipe of the exhaust system removed to expose the continuous variable transmission of the snowmobile; and 
         FIG. 9  is a left side elevation view of the portion of the snowmobile shown in  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIGS. 1 to 5 , a snowmobile  10  includes a front end  12  and a rear end  14  which are defined consistently with a forward travel direction of the snowmobile  10 . The snowmobile  10  includes a vehicle body in the form of a frame  16  which includes a rear tunnel  18  and a motor module  20 . The tunnel  18  is formed from sheet metal parts assembled to form an inverted U-shape when viewed from the front or rear end  12 ,  14 . The inverted U-shaped tunnel  18  has a left side portion  18   a  and a right side portion  18   b.    
     A motor  26 , which in the present implementation is an internal combustion engine (schematically illustrated in  FIG. 1 ), is carried in a motor compartment defined in part by the motor module  20  of the frame  16 . The engine  26  provides propulsion of the snowmobile  10 . The internal construction of the engine  26  may be of any known type such as a two-stroke engine, a four-stroke engine or a diesel engine. It is contemplated that the engine  26  could be replaced by other types of motors, such as, but not limited to, an electric motor or an electric/internal combustion hybrid engine. In the present implementation, the engine  26  is a two-stroke, in-line, two cylinder internal combustion engine. The engine  26  has a crankshaft  86  that rotates about a crankshaft rotation axis  88  extending laterally (i.e. generally transversely to a longitudinal axis  15  of the snowmobile  10 ). As will be described in more detail further below, the crankshaft  86  drives a drivetrain of the snowmobile  10  for propulsion of the snowmobile  10  on the ground. 
     A fuel tank  28 , supported on the tunnel  18 , supplies fuel to the engine  26  for its operation. The fuel tank  28  includes a cap  92  covering a fill opening of the fuel tank  28  and disposed behind a seat  60  of the snowmobile  10 . 
     The snowmobile  10  also comprises an exhaust system  90  for guiding exhaust gas away from the engine  26  to a surrounding environment of the snowmobile  10 . Notably, the exhaust system  90  comprises an exhaust pipe  93  which is fluidly connected to the engine&#39;s exhaust ports  94 , and a muffler  96  for reducing an amount of noise emitted by the exhaust system  90 . The exhaust pipe  93  is a tuned pipe in that it has a geometry suitable for improving the efficiency of the engine  26 . 
     An endless track  30  is positioned generally under the tunnel  18 , and is operatively connected to the engine  26  via a drivetrain including a transmission system  23 . The endless track  30  has a front end  37  and a rear end  39  opposite the front end  37 . The endless track  30  is driven to run about a rear suspension assembly  32  connected to the frame  16  for propulsion of the snowmobile  10 . The endless track  30  has a plurality of lugs  31  extending from an outer surface thereof to provide traction to the endless track  30 . 
     The rear suspension assembly  32  includes a pair of drive sprockets  34  mounted on a drive axle  35 , multiple idler wheels  36  and a pair of slide rails  38  in sliding contact with the endless track  30 . The drive axle  35  on which the drive sprockets  34  are mounted defines a drive sprocket rotation axis  34   a  which extends laterally (i.e., in a lateral direction of the snowmobile  10 ). The slide rails  38  are attached to the tunnel  18  by a front suspension arm  40  and a rear suspension arm  50 . The rear suspension assembly  32  further includes a front shock absorber assembly  42  and a rear shock absorber assembly  45 , each of which includes a shock absorber. It is contemplated that the snowmobile  10  could be provided with a different implementation of the rear suspension assembly  32  than the one shown herein. 
     The seat  60  of the snowmobile  10  is a straddle seat which is connected to the frame  16  and is adapted to accommodate a driver of the snowmobile  10 . In some implementations, the seat  60  may be configured to accommodate a passenger. A footrest  64  is positioned on each side of the snowmobile  10  below the seat  60  to accommodate the driver&#39;s feet. Each of the left and right footrests  64  extends generally laterally outwardly from corresponding left and right side portions of the frame  16 . 
     The snowmobile  10  further comprises fairings  66  which enclose the engine  26 , the transmission system  23  and other components of the powerpack such as an air intake system. The fairings  66  can be removed to allow access to the engine  26  and/or the transmission system  23  and other internal components of the snowmobile  10  which may be required, for example, for inspection or maintenance of the engine  26  and/or the powerpack. 
     A ski  70  positioned at the forward end  12  of the snowmobile  10  is attached to the front suspension module  22  of the frame  16  through a spindle  72 . The front suspension module  22  includes a fork  74  and a shock absorber  75 . As shown in  FIG. 3 , the ski  70  is a single laterally centered ski. In other words, the ski  70  is aligned with a centerline  73  bisecting a width of the snowmobile  10 . It is contemplated that, in some implementations, the snowmobile  10  may comprise two skis (such as the ski  70 ) which are positioned close to each other. 
     A steering assembly  80 , including two front forks  82  and a handlebar  84 , is provided generally forward of the seat  60 . The front forks  82  are rotatably connected to the frame  16 . A lower end of the front forks  82  is connected to the front suspension module  22 . The handlebar  84  is attached to an upper end of the front forks  82 . The handlebar  84  is positioned in front of the seat  60 . The handlebar  84  is operatively connected to the ski  70  such that the handlebar  84  is used to rotate the front forks, and thereby the ski  70 , in order to steer the snowmobile  10 . A left handle  85   a  and a right handle  85   b  are disposed on left and right sides of the handlebar  84  respectively. A brake actuator (not shown), in the form of a hand brake lever, is provided on the left handle  85   a  for braking the snowmobile  10  in a known manner A throttle operator (not shown) in the form of a twist grip is mounted to the right handle  85   b . Other types of throttle operators, such as a finger-actuated throttle lever and a thumb-actuated throttle lever, are also contemplated. 
     In this implementation, the snowmobile  10  also comprises a heat exchanger system  130  for cooling the engine  26 . The heat exchanger system  130  comprises a radiator  132  and a fan  134 . The radiator  132  is fluidly connected to the engine  26  such that coolant that is circulated through the engine  26  is received at the radiator  132  where the coolant exchanges heat and is returned to the engine  26 . The fan  134  is configured to blow air through the radiator  132  to aid in the convective heat exchange. 
     The snowmobile  10  includes other components such as a display cluster, an air intake system, and the like. As it is believed that these components would be readily recognized by one of ordinary skill in the art, further explanation and description of these components will not be provided herein. 
     Turning now to  FIGS. 6 to 8 , the configuration of the transmission system  23  and the engine  26  will now be described in more detail. 
     The transmission system  23  is a continuously variable transmission (CVT) and thus offers a continuous range of gear ratios. To that end, the CVT  23  comprises a primary (drive) pulley  46  operatively connected to the engine  26 , a secondary (driven) pulley  48  operatively connected to the endless track  30 , and a transmission belt  52  which operatively connects the primary pulley  46  to the secondary pulley  48 . More particularly, the primary pulley  46  has a pair of opposed frustoconical belt drive sheaves  102 ,  104  and the secondary pulley  48  has a pair of opposed frustoconical belt drive sheaves  106 ,  108 . The transmission belt  52  is located between the opposed pairs of drive sheaves  102 ,  104  and  106 ,  108 . 
     A transmission ratio of the CVT  23  can be changed by moving the sheaves of one of the primary and secondary pulleys  46 ,  48  closer together and the sheaves of the other of the primary and secondary pulleys  46 ,  48  further apart. This causes the transmission belt  52  to ride higher on one pulley and lower on the other, thus affecting the transmission ratio of the CVT  23 . In order to effect such a change in the transmission ratio of the CVT  23 , the primary pulley  46  has centrifugal actuators  115  connected to the drive sheave  104  which is moveable laterally (i.e., in an axial direction of the primary pulley  46 ) towards and away from the drive sheave  102  which is laterally fixed. As is known, the centrifugal actuators  115  generally consist of centrifugal weights in the form of adjusting arms. Each of the arms is connected to the movable sheave  104  of the primary pulley  46  by a pin, and pivots outwards about its corresponding pin. As they pivot, the arms are in contact with corresponding rollers disposed on a spider fixed relative to the movable sheave  104 . When the adjusting arms pivot outwards as a result of centrifugal force, they slide against their corresponding roller and the axially movable sheave  104  is pushed towards the fixed sheave  102 . 
     The primary pulley  46  has a primary pulley rotation axis  110  extending laterally and which is defined by a primary pulley shaft  112  onto which the primary pulley  46  is mounted. The primary pulley shaft  112  is rotatably supported by the frame  16  (e.g., via bearings). The primary pulley  46  is rotatable with the primary pulley shaft  112  such that the drive sheaves  102 ,  104  rotate together with the primary pulley shaft  112 . The primary pulley  46  is operatively connected to the crankshaft  86  of the engine  26 . In particular, in this implementation, a sprocket  122  is mounted on the primary pulley shaft  112  and another sprocket  124  is mounted on the crankshaft  86 . A chain  125  operatively connects the sprocket  124  mounted on the crankshaft  86  to the sprocket  122  mounted on the primary pulley shaft  112  such that the crankshaft  86  transmits torque to the primary pulley  46  via the chain  125  and sprockets  122 ,  124  and thus causes rotation of the primary pulley  46  about the primary pulley rotation axis  110 . A chain case  113  covers the chain  125  and sprockets  122 ,  124 . While in this implementation, a link interconnecting the crankshaft  86  to the primary pulley shaft  112  is a chain, the link may be any other suitable type of link in other implementations. For instance, it is contemplated that, in other implementations, instead of sprockets, pulleys are mounted on the crankshaft  86  and the primary pulley shaft  112  and a belt is looped about the pulleys such that the crankshaft  86  transmits torque to the primary pulley  46  via the belt and pulleys. It is contemplated that, in yet other implementations, a gear is mounted on the crankshaft  86  and another gear is mounted on the primary pulley shaft  112 . The gear mounted on the crankshaft  86  drives the gear mounted on the primary pulley shaft  112  either directly, or through an intervening component, such as an idler gear. 
     As mentioned above, the transmission belt  52  operatively connects the primary pulley  46  to the secondary pulley  48  to transmit torque thereto. In particular, as shown in  FIG. 2 , the transmission belt  52  is looped around both the primary pulley  46  and the secondary pulley  48 . In this implementation, the transmission belt  52  is made of rubber, but it is contemplated that it could be made of metal linkages or of a polymer. 
     The secondary pulley  48  has a secondary pulley rotation axis  114  extending laterally and which is defined by a secondary pulley shaft  116  onto which the secondary pulley  48  is mounted. The secondary pulley shaft  116  is rotatably supported by the frame  16  (e.g., via bearings). The secondary pulley  48  is rotatable with the secondary pulley shaft  48  such that the drive sheaves  106 ,  108  rotate together with the primary pulley shaft  112 . The secondary pulley  48  is operatively connected to the drive sprockets  34  of the rear suspension assembly  32  such that the secondary pulley  48  transmits torque to the drive sprockets  34  which in turn drive the endless track  30 . In this implementation, a sprocket  126  is mounted on the secondary pulley shaft  116  and another sprocket  128  is mounted on the drive axle  35 . A chain  127  operatively connects the sprocket  126  mounted on the secondary pulley shaft  116  to the sprocket  128  mounted on the drive axle  35  such that the secondary pulley shaft  116  transmits torque to the drive axle  35  via the chain  127  and sprockets  126 ,  128  and thus causes rotation of the drive sprockets  34  about the drive sprocket rotation axis  34   a . A chain case  117  covers the chain  127  and sprockets  126 ,  128 . While in this implementation, a link interconnecting the secondary pulley shaft  116  to the drive axle  35  is a chain, the link may be any other suitable type of link in other implementations. For instance, it is contemplated that, in other implementations, instead of sprockets, pulleys are mounted on the secondary pulley shaft  116  and the drive axle  35  and a belt is looped about the pulleys such that the secondary pulley shaft  116  transmits torque to the drive axle  35  via the belt and pulleys. It is contemplated that, in yet other implementations, a gear is mounted on the secondary pulley shaft  116  and another gear is mounted on the drive axle  35 . The gear mounted on the secondary pulley shaft  116  drives the gear mounted on the drive axle  35  either directly, or through an intervening component, such as an idler gear. 
     With reference to  FIGS. 7 to 9 , in this implementation, the sprockets  122 ,  124  and the chain  125  are disposed on a right side of the CVT  23  while the sprockets  126 ,  128  and the chain  127  are disposed on a left side of the CVT  23 . More specifically, the primary pulley  46 , the secondary pulley  48  and the transmission belt  52  are positioned laterally between, on one lateral side thereof, the sprockets  122 ,  124  and the chain  125  which operatively connect the engine  26  to the CVT  23 , and on the other lateral side, the sprockets  126 ,  128  and the chain  127  which operatively connect the CVT  23  to the drive axle  35 . In implementations in which pulleys and a belt or other types of drive members (e.g., gears) operatively connect the engine  26  to the CVT  23  and/or the CVT  23  to the drive axle  35 , the primary pulley  46  and the secondary pulley  48  are positioned laterally between the drive members that operatively connect the engine  26  to the CVT  23  and the drive members that operatively connect the CVT  23  to the drive axle  35 . 
     As shown in  FIGS. 8 and 9 , the CVT  23  is positioned forwardly of the engine  26 . In other words, a front end  118  of the engine  26  (i.e., a front surface  135  of a cylinder block and crankcase of the engine  26 ) is disposed rearwardly of the CVT  23  including the primary pulley  46 , the secondary pulley  48  and the transmission belt  52 . This positioning of the CVT  23  relative to the engine  26  may help minimize a combined lateral extent of the engine  26  and the CVT  23  which, conventionally, are positioned side-by-side (i.e., laterally adjacent). 
     The primary and secondary pulleys  46 ,  48  of the CVT  23  are therefore positioned between lateral sides  55 ,  57  of the engine  26 . That is, the primary and secondary pulleys  46 ,  48  are confined within a lateral extent of the engine  26 . Furthermore, the rotation axes  110 ,  114  of the primary and secondary pulleys  46 ,  48  of the CVT  23  are both located forwardly of the engine  26 . In other words, the primary pulley rotation axis  110  is positioned forwardly of the crankshaft rotation axis  88 . Similarly, the secondary pulley rotation axis  114  is positioned forwardly of the crankshaft rotation axis  88 . Moreover, the secondary pulley rotation axis  114  is positioned forwardly of the primary pulley rotation axis  110 . The secondary pulley rotation axis  114  is also vertically lower than the primary pulley rotation axis  110 . 
     For its part, the engine  26  is positioned further rearward than in conventional snowmobile designs. This distributes a greater proportion of weight of the snowmobile  10  and its driver onto the endless track  30  rather than the ski  70  which may result in improved maneuvering of the snowmobile  10  when travelling over deep snow. 
     For instance, in this implementation, the engine  26  is fully positioned above (i.e. an entirety of the engine  26  is positioned above) the endless track  30  and rearward of the front end  37  of the endless track  30 . However, it is contemplated that, in some implementations, rather than the entirety, a majority of the engine  26  is positioned above the endless track  30  and rearward of the front end  37  of the endless track  30 , or that only part of the engine  26  is positioned above the endless track  30  and rearward of the front end  37  of the endless track  30 . Moreover, the drive sprocket rotation axis  34   a  is positioned forwardly of the crankshaft rotation axis  88 . Furthermore, the seat  60  is positioned above the engine  26 . The engine  26  is positioned above the tunnel  18  of the frame  16 . 
     Furthermore, the exhaust system  90  of the snowmobile  10  is positioned forwardly of the engine  26 . More specifically, the exhaust pipe  93  has an end  105  and an end  107 . The end  105  of the exhaust pipe  93  is fluidly connected to exhaust ports  94  of the engine  26  via an exhaust manifold  120  of the exhaust system  90 . The end  105  is positioned rearwardly of the primary pulley rotation axis  110 . The exhaust pipe  93  extends forwardly from the end  105  of the exhaust pipe  93  past the secondary pulley rotation axis  114 . 
     The muffler  96  is fluidly connected to the end  107  of the exhaust pipe  93 . The muffler  96  is positioned particularly low relative to the CVT  23 . Notably, in this implementation, part of the muffler  96  extends below the secondary pulley rotation axis  114 . Thus, as shown in  FIG. 9 , the exhaust pipe  93  extends forward from the end  105  of the exhaust pipe  93  past the secondary pulley  48  and downward in front of the secondary pulley  48  where the end  107  of the exhaust pipe  93  is connected to the muffler  96 . The muffler  96  then extends rearward under the secondary pulley  48  from the end  107  of the exhaust pipe  93 . 
     The radiator  132  and the fan  134  of the heat exchanger system  130  are positioned forwardly of the CVT  23 . More specifically, as shown in  FIGS. 8 and 9 , the radiator  132  and the fan  134  are positioned forwardly of the secondary pulley  48 . The exhaust pipe  93  extends forward from the end  105  of the exhaust pipe  93  past the radiator  132  and the fan  134  and downward past the radiator  132  and the fan  134  where the end  107  of the exhaust pipe  93  is connected to the muffler  96 . The muffler  96  then extends rearward under the radiator  132  and the fan  134  from the end  107  of the exhaust pipe  93  and past the radiator  132  and the fan  134 . 
     Modifications and improvements to the above-described implementations of the present technology may become apparent to those skilled in the art. The foregoing description is intended to be exemplary rather than limiting. The scope of the present technology is therefore intended to be limited solely by the scope of the appended claims.