Patent Application
20250083771
The present disclosure relates, in general, to engines for use on land vehicles and, in particular, to four-stroke engines for use on snowmobiles that include a plurality of intake ports positioned on an aft side of the engine and a plurality of exhaust ports positioned on a forward side of the engine.
Snowmobiles are popular recreational vehicles used in snowy and icy environments. Snowmobiles may be designed for specific applications such as trail, utility, mountain, race and crossover, to name a few. Snowmobiles typically include a pair of ski assemblies coupled to the forward end of a chassis that provide for the maneuverability of the snowmobile during these various winter activities. In addition, snowmobiles typically include a ground-engaging endless drive track disposed in an aftwardly extending drive tunnel of the chassis, with the length and design of the drive track contributing to the stability, flotation, agility, responsiveness and overall performance of the snowmobile. Power is delivered to the drive track from a powertrain that is coupled to the chassis and typically includes an engine and a transmission, such as a continuously variable transmission. The engine used in conventional snowmobiles is typically a two-stroke internal combustion engine due to the compact size and efficient design of such engines. While two-stroke engines are considered to have a high power-to-weight ratio, they also tend to produce undesirable pollution due to the direct mixing of fuel and oil. Four-stroke internal combustion engines, on the other hand, have higher fuel efficiency, generate lower emissions, produce less noise and have a simplified refueling process, which not only reduces the cost and environmental impact of operations, but also enhances the enjoyment of the riding experience on snowmobiles having such engines.
In a first aspect, the present disclosure is directed to a snowmobile that has a forward frame assembly defining an engine bay. The forward frame assembly includes a nose frame assembly having a nose frame cross member positioned forward of the engine bay. An engine is positioned within the engine bay. A tunnel is coupled to the forward frame assembly and is positioned aft of the engine bay. A heat exchanger is coupled to a forward end of the tunnel. First and second aftward engine mounts couple the engine to the heat exchanger. First and second forward engine mounts couple the engine to nose frame cross member.
In some embodiments, the forward frame assembly may include a base frame assembly that is coupled to the nose frame assembly such that the engine is suspended above the base frame assembly by the aftward and forward engine mounts. In certain embodiments, the engine may be a four-stroke engine and/or the aftward tilt angle of the engine may be between five degrees and thirty degrees relative to the vertical plane such as between ten degrees and twenty degrees relative to the vertical plane. In some embodiments, each of the aftward engine mounts may include an aperture having a vibration damper disposed therein. In certain embodiments, the aftward engine mounts may damp vibration between the engine and the heat exchanger and the forward engine mounts may damp vibration between the engine and the forward frame assembly. In some embodiments, the aftward engine mounts may be above the forward engine mounts. In certain embodiments, the aftward engine mounts may be outboard of the forward engine mounts.
In some embodiments, the first aftward engine mount may have a mount axis that is substantially horizontal, the second aftward engine mount may have a mount axis that is substantially horizontal, the first forward engine mount may have a mount axis that is substantially parallel to the aftward tilt angle of the engine and the second forward engine mount may have a mount axis that is substantially parallel to the aftward tilt angle of the engine. In certain embodiments, the mount axes of the first and second aftward engine mounts may extend in a lateral direction including, for example, in a common lateral direction. In some embodiments, the mount axes of the first and second aftward engine mounts may extend substantially normal to the mount axes of the first and second forward engine mounts. In certain embodiments, first and second mounting brackets may be coupled to the heat exchanger such that the first and second aftward engine mounts may be respectively coupled to the first and second mounting brackets. In some embodiments, a driven shaft may be operatively coupled to the engine and a bearing hub may be coupled to the chassis with the bearing hub supporting a bearing assembly. In such embodiments, the driven shaft may be rotatably coupled to the bearing hub by the bearing assembly and the bearing hub may be coupled to the first aftward engine mount. Also, in such embodiments, a first mounting bracket may be coupled to the heat exchanger such that the first aftward engine mount may be coupled between the first mounting bracket and the bearing hub.
In certain embodiments, a drive track system may be at least partially disposed within the tunnel with the drive track system including a track driveshaft having an axis of rotation. In such embodiments, the first aftward engine mount may have a mount axis that is oriented in a substantially radial direction relative to the axis of rotation of the track driveshaft, the second aftward engine mount may have a mount axis that is oriented in a substantially radial direction relative to the axis of rotation of the track driveshaft, the first forward engine mount may have a mount axis that is substantially parallel to the aftward tilt angle of the engine and the second forward engine mount may have a mount axis that is substantially parallel to the aftward tilt angle of the engine. In some embodiments, the heat exchanger may include an engine mounting system positioned on a forward wall of the heat exchanger with the aftward engine mounts coupled to the engine mounting system. In certain embodiments, the heat exchanger may include an engine mounting system integrally formed on the forward wall of the heat exchanger with the aftward engine mounts coupled to the engine mounting system. In some embodiments, the heat exchanger may include mounting rails positioned on the forward wall of the heat exchanger with the aftward engine mounts coupled to the mounting rails. In certain embodiments, the heat exchanger may include mounting rails integrally formed on the forward wall of the heat exchanger with the aftward engine mounts coupled to the mounting rails. In some embodiments, the mounting rails may include first and second recessed mounting locations configured to respectively receive the first and second aftward engine mounts therein. In certain embodiments, each of the first and second aftward engine mounts may include a mounting flange such that the mounting flanges of the first and second aftward engine mounts are respectively received in the first and second recessed mounting locations. In some embodiments, the mounting rails may include upper and lower slots, the mounting flange of the first aftward engine mount may be coupled to first recessed mounting location using first upper and lower bolts that are respectively secured within the upper and lower slots and the mounting flange of the second aftward engine mount may be coupled to second recessed mounting location using second upper and lower bolts that are respectively secured within the upper and lower slots.
In a second aspect, the present disclosure is directed to a snowmobile that has a forward frame assembly defining an engine bay. The forward frame assembly includes a nose frame assembly having a nose frame cross member positioned forward of the engine bay. An engine is positioned within the engine bay and has an aftward tilt angle relative to a vertical plane. A tunnel is coupled to the forward frame assembly and is positioned aft of the engine bay. A drive track system is positioned at least partially within the tunnel. The drive track system includes a track driveshaft having an axis of rotation. A heat exchanger is coupled to a forward end of the tunnel. The heat exchanger includes an engine mounting system positioned on a forward wall of the heat exchanger, such as mounting rails integrally formed on a forward wall of the heat exchanger. First and second forward engine mounts couple the engine to nose frame cross member. First and second aftward engine mounts couple the engine to the engine mounting system. Each of the aftward engine mounts has a mount axis that is oriented in a substantially radial direction relative to the axis of rotation of the track driveshaft.
In a third aspect, the present disclosure is directed to a forward frame assembly for a snowmobile. The forward frame assembly includes a welded frame assembly that has a base frame assembly with a nose frame assembly that is welded thereto. A first side frame assembly is welded to the base frame assembly and the nose frame assembly. The first side frame assembly includes a first forward spar. A fixed portion of a second side frame assembly is welded to the base frame assembly and the nose frame assembly. A steering column mount is welded between the first side frame assembly and the fixed portion of the second side frame assembly. The forward frame assembly also has a separable portion of the second side frame assembly that is couplable to the fixed portion of the second side frame assembly with non-permanent fasteners. The separable portion of the second side frame assembly includes a second forward spar.
In certain embodiments, the base frame assembly may include first and second base beams and a base cross member welded to the first and second base beams. In some embodiments, the nose frame assembly may include first, second and third nose trusses, a nose frame cross member welded to the first and second nose trusses and a nose rail welded to each of the first, second and third nose trusses. In such embodiments, each of the first, second and third nose trusses may be welded to the base frame assembly. In certain embodiments, the first side frame assembly may include a first joint welded to the first forward spar, a first upper beam welded to the first joint, a first aft spar welded to the first upper beam and a first plate member welded to the first aft spar. In such embodiments, the first joint may be welded to the nose frame assembly and the first plate member may be welded to the base frame assembly. In some embodiments, the fixed portion of the second side frame assembly may include a top flange, a second joint having an upper flange and an aft flange, a second aft spar and a second plate member that is welded to the second aft spar and has an upper flange. In such embodiments, the top flange and the second aft spar may be welded to the steering column mount, the second joint may be welded to the nose frame assembly and/or the second plate member may be welded to the base frame assembly.
In certain embodiments, the separable portion of the second side frame assembly may include a second upper beam that is couplable to the aft flange of the second joint and to the upper flange of the second plate member with non-permanent fasteners and the second forward spar may be couplable to the upper flange of the second joint and to the top flange with non-permanent fasteners. In some embodiments, an upper cross member may be welded to the second forward spar and the first forward spar may include a lateral flange. In such embodiments, the upper cross member may be couplable to the lateral flange of the first forward spar with a non-permanent fastener. In certain embodiments, each of the first forward spar and the second forward spar may be a bent spar such that the first forward spar and the second forward spar are bent in a forward direction to provide engine clearance.
In a fourth aspect, the present disclosure is directed to a snowmobile having a chassis that includes a forward frame assembly coupled to a tunnel. A heat exchanger is coupled to a forward end of the tunnel such that the forward frame assembly and the heat exchanger defining an engine bay. An engine is positioned within the engine bay and is coupled to the forward frame assembly and the heat exchanger. The forward frame assembly includes a welded frame assembly that has a base frame assembly with a nose frame assembly that is welded thereto. A first side frame assembly is welded to the base frame assembly and the nose frame assembly. The first side frame assembly includes a first forward spar. A fixed portion of a second side frame assembly is welded to the base frame assembly and the nose frame assembly. A steering column mount is welded between the first side frame assembly and the fixed portion of the second side frame assembly. The forward frame assembly also includes a separable portion of the second side frame assembly that is couplable to the fixed portion of the second side frame assembly with non-permanent fasteners. The separable portion of the second side frame assembly includes a second forward spar.
In some embodiments, the first side frame assembly may include a first plate member and the fixed portion of the second side frame assembly may include second plate member. In such embodiments, the heat exchanger may be coupled between the first and second plate members. In certain embodiments, the nose frame assembly may include a nose frame cross member. In such embodiments, the engine may be coupled between the nose frame cross member and the heat exchanger.
In a fifth aspect, the present disclosure is directed to a method for assembling a snowmobile. The method includes providing a welded frame assembly including a base frame assembly, a nose frame assembly welded to the base frame assembly, the nose frame assembly including a nose frame cross member, a first side frame assembly welded to the base frame assembly and the nose frame assembly, the first side frame assembly including a first forward spar, a fixed portion of a second side frame assembly welded to the base frame assembly and the nose frame assembly and a steering column mount welded between the first side frame assembly and the fixed portion of the second side frame assembly; forming an engine bay by coupling a heat exchanger to the first side frame assembly and the fixed portion of the second side frame assembly; suspending an engine within the engine bay above the base frame assembly by coupling the engine to the nose frame cross member and the heat exchanger; and coupling a separable portion of the second side frame assembly to the fixed portion of the second side frame assembly with non-permanent fasteners, the separable portion of the second side frame assembly including a second forward spar.
In some embodiments, the method may include providing a base frame assembly having first and second base beams and a base cross member welded to the first and second base beams; providing a nose frame assembly having first, second and third nose trusses, the nose frame cross member welded to the first and second nose trusses, a nose rail welded to each of the first, second and third nose trusses with each of the first, second and third nose trusses welded to the base frame assembly; and/or providing a first side frame assembly having a first joint welded to the first forward spar, a first upper beam welded to the first joint, a first aft spar welded to the first upper beam and a first plate member welded to the first aft spar, with the first joint welded to the nose frame assembly and the first plate member welded to the base frame assembly.
In certain embodiments, the method may include providing a fixed portion of the second side frame assembly having a top flange, a second joint having an upper flange and an aft flange, a second aft spar and a second plate member welded to the second aft spar and having an upper flange with the top flange and the second aft spar welded to the steering column mount, the second joint welded to the nose frame assembly and the second plate member welded to the base frame assembly; coupling the second forward spar to the upper flange of the second joint and to the top flange with the non-permanent fasteners; coupling a second upper beam to the aft flange of the second joint and to the upper flange of the second plate member with the non-permanent fasteners; and/or coupling an upper cross member that is welded to the second forward spar to a lateral flange of the first forward spar with the non-permanent fastener.
In some embodiments, the method may include having a fluid conduit coupled to a forward side of the heat exchanger. In certain embodiments, the method may include having first and second engine mounting brackets on a forward side of the heat exchanger or having engine mounting rails on the forward side of the heat exchanger. In some embodiments, the method may include laterally inserting the engine into the welded frame assembly through a window in the fixed portion of the second side frame assembly; shifting the engine forward relative to the welded frame assembly; and lowering the engine onto the nose frame cross member. In certain embodiments, the method may include coupling two forward engine mounts to the nose frame cross member and coupling at least one aft engine mount to the heat exchanger. In other embodiments, the method may include coupling two forward engine mounts to the nose frame cross member and coupling two aft engine mounts to the heat exchanger. In certain embodiments, the method may include inserting studs of two forward engine mounts through openings of the nose frame cross member as the engine is lowered relative to the welded frame assembly.
In some embodiments, the method may include having an exhaust manifold and an air runner assembly coupled to the engine prior to inserting the engine into the welded frame assembly. In such embodiments, the method may include coupling an air plenum to the air runner assembly after suspending the engine within the engine bay and before coupling the separable portion of the second side frame assembly to the fixed portion of the second side frame assembly; coupling an airbox to the first and second forward spars; and coupling an air duct between the airbox and the air plenum with the air duct routed forward of and outboard of the second forward spar. In certain embodiments, the method may include having an exhaust manifold, an air runner assembly and an air plenum coupled to the engine prior to inserting the engine into the welded frame assembly. In some embodiments, the method may include positioning the engine within the engine bay with an aftward tilt angle relative to a vertical plane and with forward and aft engine mounts located above a crankshaft of the engine.
In a sixth aspect, the present disclosure is directed to a snowmobile having a forward frame assembly that defines an engine bay. An engine is positioned within the engine bay. The engine has a plurality of intake ports positioned on an aft side of the engine and a plurality of exhaust ports positioned on a forward side of the engine. An air intake system has at least one air inlet and a plurality of air outlets. The air intake system is coupled to the aft side of the engine such that each of the air outlets is configured to provide air to one of the intake ports. An exhaust system has a plurality of exhaust inlets and at least one exhaust outlet. The exhaust system is coupled to the forward side of the engine such that each of the exhaust inlets is configured to receive exhaust from one of the exhaust ports.
In certain embodiments, the engine may be a four-stroke engine. In some embodiments, the air intake system may include an airbox positioned at least partially forward of the engine bay. The airbox may include the at least one air inlet which may be positioned outboard of the engine bay. In certain embodiments, the air intake system may include an air plenum that is positioned on top of the engine. In some embodiments, the air plenum may be positioned at least partially within the engine bay. In certain embodiments, the air intake may include a throttle valve assembly coupled to the air plenum. The throttle valve assembly may be positioned outboard of the engine bay and/or below the at least one air inlet. In some embodiments, the air intake system may include an air duct coupled between the airbox and the throttle valve assembly that is routed forward and outboard of the forward frame assembly. In certain embodiments, the air intake system may include an air runner assembly coupled between the air plenum and the aft side of the engine. The air runner assembly may include the plurality of air outlets and may extends aftward and downward from the air plenum. In some embodiments, the exhaust system may include an exhaust manifold coupled to the forward side of the engine. The exhaust manifold may include the exhaust inlets. In certain embodiments, the exhaust system may include a muffler positioned outboard of the engine bay. In some embodiments, the air intake system may include a throttle valve assembly positioned outboard of the engine bay on a first side of the engine and the exhaust system may include a muffler positioned outboard of the engine bay on a second side of the engine that is opposite the first side of the engine.
In a seventh aspect, the present disclosure is directed to a snowmobile including a forward frame assembly that defines an engine bay. An engine is positioned within the engine bay. The engine has a plurality of intake ports positioned on an aft side of the engine and a plurality of exhaust ports positioned on a forward side of the engine. An air intake system is coupled to the aft side of the engine. The air intake system includes an airbox having an air inlet that is positioned outboard of the engine bay, an air plenum positioned on top of the engine, a throttle valve assembly coupled between the airbox and the air plenum, the throttle valve assembly positioned outboard of the engine bay on a first side of the engine and an air runner assembly coupled between the air plenum and the engine, the air runner assembly including a plurality of air outlets each of which is configured to provide air to one of the intake ports. An exhaust system is coupled to the forward side of the engine. The exhaust system includes an exhaust manifold having a plurality of exhaust inlets each of which is configured to receive exhaust from one of the exhaust ports and a muffler including an exhaust outlet positioned outboard of the engine bay on a second side of the engine that is opposite of the first side. Each of the engine, the air plenum, the air runner assembly and the exhaust manifold is at least partially disposed within the engine bay.
In certain embodiments, the throttle valve assembly may be positioned below the air inlet. In some embodiments, the air runner assembly may extend aftward and downward from the air plenum. In certain embodiments, the engine may be tilted aftward such that an upper portion of the engine is aft of a lower portion of the engine. In some embodiments, a heat exchanger may be coupled to the forward frame assembly forward of the engine. In such embodiments, the heat exchanger may be tilted forward such that an upper portion of the heat exchanger is forward of a lower portion of the heat exchanger. In certain embodiments, at least a portion of the exhaust manifold may be positioned between the heat exchanger and the engine. In some embodiments, the muffler may be positioned aft of the heat exchanger.
For a more complete understanding of the features and advantages of the present disclosure, reference is now made to the detailed description along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
While the making and using of various embodiments of the present disclosure are discussed in detail below, it should be appreciated that the present disclosure provides many applicable inventive concepts, which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative and do not delimit the scope of the present disclosure. In the interest of clarity, all features of an actual implementation may not be described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present disclosure, the devices, members, apparatuses, and the like described herein may be positioned in any desired orientation. Thus, the use of terms such as “above,” “below,” “upper,” “lower” or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the devices described herein may be oriented in any desired direction. As used herein, the term “coupled” may include direct or indirect coupling by any means, including by mere contact or by moving and/or non-moving mechanical connections.
Referring to
Various components of snowmobile 10 are assembled on or around forward frame assembly 14. One or more body panels 20 cover and protect the various components of snowmobile 10 including parts of forward frame assembly 14. For example, a hood panel 20a, a nose panel 20b, an upper right side panel 20c and a lower right side panel 20d shield underlying componentry from the snow and terrain. Similarly, an upper left side panel and a lower left side panel (not visible) also shield underlying componentry from the snow and terrain. In the illustrated embodiment, snowmobile 10 has a windshield 22 that shields the rider of snowmobile 10 from snow, terrain and frigid air during operation. Even through snowmobile 10 has been described and depicted as including specific body panels 20, it should be understood by those having ordinary skill in the art that a snowmobile of the present disclosure may include any number of body panels in any configuration to provide the shielding functionality. In addition, it should be understood by those having ordinary skill in the art that the right side and the left side of snowmobile 10 will be with reference to a rider of snowmobile 10 with the right side of snowmobile 10 corresponding to the right side of the rider and the left side of snowmobile 10 corresponding to the left side of the rider.
Body panels 20 have been removed from snowmobile 10 in
It should be noted that the engine used in conventional snowmobiles is typically a naturally aspirated two-stroke internal combustion engine due to the compact size and efficient design of such engines. While such two-stroke engines have a high power-to-weight ratio, they typically have low fuel efficiency, generate high noise levels and produce undesirable pollution due to the direct mixing of fuel and oil. Naturally aspirated four-stroke internal combustion engines, on the other hand, have higher fuel efficiency, produce less noise, generate lower emissions and have a simplified refueling process, which not only reduces the cost and environmental impact of operations, but also enhances the enjoyment of the riding experience. It has been found, however, that to produce the same power, four-stroke engines must generally be larger and heavier than two-stroke engines. Numerous design features discussed herein, such as the placement and design of the component of the air intake system, the placement and design of the components of the exhaust system and the placement and design of the components of the cooling system allow for the use of engine 26, a larger four-stroke engine, in the same package space as a smaller two-stroke engine in prior snowmobiles. Additional features may further enable an overall height reduction of engine 26 so that engine bay 26a can fit within engine bay 26a. For example, the scavenge pumps of engine 26 may be positioned upward within a cavity of the crankcase forward of the crankshaft such as the forwardly offset scavenge pumps described in commonly owned U.S. patent application Ser. No. 18/650,021, filed Apr. 29, 2024, the entire contents of which are incorporated by reference herein for all purposes. In addition, size reduction of engine 26 can be gained by machining the crankshaft to include sprockets such as the crankshaft described in commonly owned U.S. patent application Ser. No. 18/670,693, filed May 21, 2024, the entire contents of which are incorporated by reference herein for all purposes. Further, angling the valve fingers of engine 26 with respect to the intake/exhaust valves reduces the amount of material required compared to arranging the valve fingers parallel to each other such as the valve fingers described in commonly owned U.S. patent application Ser. No. 18/671,970, filed May 22, 2024, the entire contents of which are incorporated by reference herein for all purposes.
A drive track system 32 is at least partially disposed within and/or below tunnel 18 and is in contact with the ground to provide ground propulsion for snowmobile 10. Torque and rotational energy are provided to drive track system 32 from engine 26 via drivetrain 28. Drive track system 32 includes a track frame 34, an internal suspension 36, a plurality of idler wheels 38 such as idler wheels 38a, 38b, 38c, 38d and an endless track 40. Track frame 34 may be coupled to forward frame assembly 14 via a swing arm having a coil spring, a rigid strut, a torsion spring, an elastomeric member or any other suitable coupling configuration. Endless track 40 is driven by a track drive sprocket 42 via a track driveshaft 44 (see also
Snowmobile 10 has a ski system 52 and a front suspension assembly 54 that provide front end support for snowmobile 10. Ski system 52 includes a right ski 52a that is coupled to forward frame assembly 14 by upper and lower A-arms 52b, 52c and right spindle 52d. Ski system 52 also includes a left ski 52e that is coupled to forward frame assembly 14 by upper and lower A-arms 52f, 52g and left spindle 52h. Skis 52a, 52e are interconnected to a steering system 56 including a handlebar assembly 56a, a steering column 56b, a right tie rod 56c and a left tie rod 56d that enable the rider to steer snowmobile 10. For example, when handlebar assembly 56a is rotated, skis 52a, 52e responsively pivot to turn snowmobile 10. The rider controls snowmobile 10 from a seat 58 that is position atop a fuel tank 60, above tunnel 18, aft of handlebar assembly 56a and aft of forward frame assembly 14. Snowmobile 10 has a lift bumper 62 that is coupled to an aft end of tunnel 18 that enables a person to lift the rear end of snowmobile 10 in the event snowmobile 10 becomes stuck or needs to be repositioned when it is not moving. Snowmobile 10 has a snow flap 64 that deflects snow emitted by endless track 40. In the illustrated embodiment, snow flap 64 is coupled to lift bumper 62. In other embodiments, a snow flap may be coupled directly to tunnel 18. A taillight housing 66 is also coupled to lift bumper 62 and houses a taillight of snowmobile 10. Snowmobile 10 has an exhaust system 70 (see also
It should be appreciated that snowmobile 10 is merely illustrative of a variety of vehicles that can implement the embodiments disclosed herein. Other vehicle implementations can include motorcycles, snow bikes, all-terrain vehicles (ATVs), utility vehicles, recreational vehicles, scooters, automobiles, mopeds, straddle-type vehicles and the like. As such, those skilled in the art will recognize that the embodiments disclosed herein can be integrated into a variety of vehicle configurations. It should be appreciated that even though ground-based vehicles are particularly well-suited to implement the embodiments of the present disclosure, airborne vehicles and devices such as aircraft can also implement the embodiments.
Referring additionally to
Engine cooling system 100 further includes a tunnel heat exchanger 106 that is positioned along a top portion of tunnel 18. Tunnel heat exchanger 106 is configured to remove heat from a fluid circulating therethrough responsive to snow in tunnel 18. For example, during operation of snowmobile 10, endless track 40 kicks snow toward an upper surface of tunnel 18, a portion of which sticks to this surface which is in thermal communication with tunnel heat exchanger 106. Heat from the fluid circulating through tunnel heat exchanger 106 is transferred to the retained snow causing the retained snow to melt. It is note that snow flap 64 helps to retain snow in tunnel 18 which aids in the snow sticking to the upper surface of tunnel 18. Together, radiator 102, arcuate heat exchanger 104 and tunnel heat exchanger 106 form a cooling circuit that is in fluid communication with engine 26. More specifically, radiator 102 is coupled to a fluid discharge port 108 (see also
Referring next to
Driven pulley 134 provides torque and rotational energy to a driven shaft 138. In the illustrated embodiment, driven shaft 138 includes multiple splined sections including input splines 138a and output splines 138b. Input splines 138a are in mesh with splines within driven pulley 134 such that operation of transmission 30 rotates driven shaft 138. Output splines 138b are in mesh with splines within drive assembly 140 that is depicted as a reduction drive assembly that is shiftable been a forward mode and a reverse mode which determines the direction 48a or 48b (see also
Referring now to
Referring additionally to
Air plenum 182 is configured to damp the air flow prior to distribution to cylinders 172 via an air runner assembly 188. Air runner assembly 188 include the air outlets of air intake system 176; namely, right air outlet 188a, center air outlet 188b and left air outlet 188c. As best seen by comparison of
As best seen in
Referring now to
In the illustrated embodiment, base frame assembly 204 include a right base frame beam 204a, a left base frame beam 204b and a base frame cross member 204c that is welded between right and left base frame beams 204a, 204b. Nose frame assembly 202 includes a right nose truss 202a, a left nose truss 202b, a center nose truss 202c, a nose frame cross member 202d and a nose rail 202e. Right nose truss 202a is welded to right base frame beam 204a. Left nose truss 202b is welded to left base frame beam 204b. Center nose truss 202c is welded to right base frame beam 204a and left base frame beam 204b. Nose frame cross member 202d is welded between right nose truss 202a and left nose truss 202b. Nose rail 202e is welded to each of right nose truss 202a, left nose truss 202b and center nose truss 202c. Right side frame assembly 206 including a right side forward spar 206a, a right side aftward spar 206b, a right side upper beam 206c, a right side joint 206d, a lateral flange 206e and right side plate member 16a. Right side joint 206d is welded to nose rail 202e, right side forward spar 206a is welded between right side joint 206d and steering column mount 210, right side aftward spar 206b is welded to steering column mount 210, right side upper beam 206c is welded between right side joint 206d and right side aftward spar 206b, lateral flange 206e is welded to right side forward spar 206a and right side plate member 16a is welded to right side aftward spar 206b, right side upper beam 206c and right base frame beam 204a.
The fixed portion of left side frame assembly 208 includes a left side aftward spar 208b, a left side joint 208d and left side plate member 16b. Left side joint 208d is welded to nose rail 202e, left side aft spar 208b is welded to steering column mount 210, and left side plate member 16b is welded to left side aft spar 208b and left base frame beam 204b. In the illustrated embodiment, the fixed portion of left side frame assembly 208 includes a top flange 208f that is welded to or integral with steering column mount 210, an upper flange 208g and an aft flange 208h that are welded to or integral with left side joint 208d and an upper flange 208i that is welded to or integral with left side plate member 16b. As discussed herein, the fixed portion of left side frame assembly 208 includes an engine installation window 208e that is disposed between left side joint 208d, left side aftward spar 208b and left side plate member 16b. A lower forward cross member 210a is welded between right side joint 206d and left side joint 208d. In this configuration, welded frame assembly 200 provides efficiency to the construction of snowmobile 10.
As best seen in the comparison of
Once heat exchanger 104 has been coupled to welded frame assembly 200, engine 26 may now be positioned within engine bay 26a as best seen in the progression of
As best seen in
Engine 26 is now secured to welded frame assembly 200 and heat exchanger 104 at three points; namely, nut 230a secures right forward engine mount 214 to nose frame cross member 202d, nut 230b secures left forward engine mount 216 to nose frame cross member 202d and bolt assembly 224 secures right aftward engine mount 218 to right mounting bracket 212a (see also
With engine 26 positioned within engine by 26a and suspended above base frame assembly 204, non-preinstalled components of air intake system 176 may now be assembled onto engine 26. As best seen in
As best seen in
In addition,
As best seen in
For example, as best seen in
Referring additionally to
Nose frame assembly 202 including nose frame cross member 202d having openings 202f, 202g (see also
Referring next to
An arcuate heat exchanger 306 is coupled to tunnel 18 and welded frame assembly 200 using rivets or other suitable connection means including by coupling the end caps of arcuate heat exchanger 306 to right side plate member 16a and left side plate member 16b of welded frame assembly 200. Arcuate heat exchanger 306 has an arcuate inner surface 306a which has a substantially constant radius of curvature 306b and an arcuate outer wall 306c which has a substantially constant radius of curvature 306d. Radii of curvature 306b, 306d share a common center of curvature 306e that is coincident with axis of rotation 44a of track driveshaft 44. Arcuate heat exchanger 306 includes a mounting system depicted as mounting rails 308 that are preferably formed integrally with outer wall 306c using, for example, an extrusion process followed by a machining process and thus does not require welding of non-integral brackets to the forward side of outer wall 306c. Mounting rails 308 include a right recessed mounting location 308a and a left recessed mounting location 308b that may be machined into mounting rails 308 to receive the right and left aftward engine mounts therein. Mounting rails 308 also include upper and lower slots 308c, 308d sized to receive and secure bolt heads therein such that the right and left aftward engine mounts can be coupled thereto.
The present engine mounting system includes a right forward engine mount 314, a left forward engine mount 316, a right aftward engine mount 318 and a left aftward engine mount 320. In the illustrated embodiments, right forward engine mount 314 includes an angled bracket 314a that is bolted to a forward side of engine 26. A mounting flange 314b and a vibration damper 314c are secured to angled bracket 314a with a bolt 314d along mounting axis 314e. Mounting flange 314b is coupled to nose frame cross member 300 with bolts 314f, 314g that extend through right openings 302a, 302b to resiliently secure right forward engine mount 314 to nose frame cross member 300 such that mount axis 314e extends in a direction that is substantially parallel to aftward tilt angle 168 of engine 26 (see also
Left forward engine mount 316 includes an angled bracket 316a that is bolted to a forward side of engine 26. A mounting flange 316b and a vibration damper 316c are secured angled bracket 316a with a bolt 316d along mounting axis 316e. Mounting flange 316b is coupled to nose frame cross member 300 with bolts 316f, 316g that extend through left openings 304a, 304b to resiliently secure left forward engine mount 316 to nose frame cross member 300 such that mount axis 316e extends in a direction that is substantially parallel to aftward tilt angle 168 of engine 26, as best seen in
Right aftward engine mount 318 has a body 318a that is bolted to an aftward side of engine 26. A mounting flange 318b and a vibration damper 318c are secured to body 318a with a bolt 318d along mounting axis 318e. Mounting flange 318b is coupled to mounting rails 308 with bolts 318f, 318g. More specifically, to install right aftward engine mount 318 to mounting rails 308, mounting flange 318b and vibration damper 318c are positioned relative to mounting rails 308 such that the head of bolt 318f is received within a central opening 308e of upper slot 308c and the head of bolt 318g is received within a central opening 308f of lower slot 308d. Mounting flange 318b and vibration damper 318c are then moved toward and properly aligned with right recessed mounting location 308a such that mounting flange 318b can be received within right recessed mounting location 308a. Thereafter, bolts 318f, 318g are tightened to secure mounting flange 318b and vibration damper 318c in place within right recessed mounting location 308a. Body 318a may be preinstalled on engine 26 and coupled to mounting flange 318b and vibration damper 318c upon positioning of engine 26 within welded frame assembly 200.
Left aftward engine mount 320 has a body 320a that is bolted to features on an aftward side of engine 26. A mounting flange 320b and a vibration damper 320c are secured to body 320a with a bolt 320d along mounting axis 320e. Mounting flange 320b is coupled to mounting rails 308 with bolts 320f, 320g. More specifically, to install left aftward engine mount 320 to mounting rails 308, mounting flange 320b and vibration damper 320c are positioned relative to mounting rails 308 such that the head of bolt 320f is received within central opening 308e of upper slot 308c and the head of bolt 320g is received within central opening 308f of lower slot 308d. Mounting flange 320b and vibration damper 320c are then moved toward and properly aligned with left recessed mounting location 308b such that mounting flange 320b can be received within left recessed mounting location 308b. Thereafter, bolts 320f, 320g are tightened to secure mounting flange 320b and vibration damper 320c in place within left recessed mounting location 308b. Body 320a may be preinstalled on engine 26 and coupled to mounting flange 320b and vibration damper 320c upon positioning of engine 26 within welded frame assembly 200.
As best seen in
Due to the resilient nature of vibration dampers 318c, 320c, vibration transfer from engine 26 to heat exchanger 306 is reduced and/or eliminated. Mounting rails 308 extend the lateral direction of snowmobile 10 and have a length that is more than half the lateral length of heat exchanger 306 and, in the illustrated embodiment, have a length of about ninety percent of the lateral length of heat exchanger 306. As such, mounting rails 308 enhance the structure of heat exchanger 306 thus providing a more robust support for engine 26. In addition, heat exchanger 306 may include internal reinforcement elements to provide added support for engine 26 such as those positioned in the heat exchanger disclosed in commonly owned U.S. patent application Ser. No. 18/666,651, filed May 16, 2024, the entire contents of which are incorporated by reference herein for all purposes.
Even though mounting rails 308 have been depicted as described as having mounting location for mounting flanges 318b, 320b, it should be understood by those having ordinary skill in the art that mounting rails 308 could be used for mounting other or additional snowmobile components thereto including, for example, a bearing hub, such as bearing hub 154 discussed herein, a gearbox assembly associated with driven shaft 138 or another desired component. Also, even though each of vibration dampers 314c, 316c, 318c, 320c has been depicted to include a threaded stud 314d, 316d, 318d, 320d respectively extending outwardly therefrom and configured to extend through a bolt opening in a respective one of bodies 314a, 316a, 318a, 320a and receive a nut, it should be understood by those having ordinary skill in the art that bodies 314a, 316a, 318a, 320a may be coupled to vibration dampers 314c, 316c, 318c, 320c using bolts that extend through the bolt openings in bodies 314a, 316a, 318a, 320a and into vibration dampers 314c, 316c, 318c, 320c. In addition, even though the bolts that couple mounting flanges 318b, 320b to mounting rails 308, such as bolt 320g, have been depicted as having square heads, it should be understood by those having ordinary skill in the art that these bolts could have heads with other shapes and/or these bolts could be used in conjunction with washers to couple mounting flanges 318b, 320b to mounting rails 308.
The foregoing description of embodiments of the disclosure has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the disclosure. The embodiments were chosen and described in order to explain the principals of the disclosure and its practical application to enable one skilled in the art to utilize the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated. For example, numerous combinations of the features disclosed herein will be apparent to persons skilled in the art including the combining of features described in different and diverse embodiments, implementations, contexts, applications and/or figures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the embodiments without departing from the scope of the present disclosure. Such modifications and combinations of the illustrative embodiments as well as other embodiments will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.
The present application claims the benefit of U.S. Provisional Application No. 63/537,179, filed Sep. 7, 2023, the entire contents of which are incorporated by reference herein for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 63537179 | Sep 2023 | US |
