Title: Lubricant tank for snowmobile lubrication system
Abstract: A lubricant tank for a lubrication system of a snowmobile engine includes an upper portion and a lower portion. The upper portion is enlarged relative to the lower portion. A recess is defined on an engine side of the lubricant tank by a lower surface of the upper portion and a lateral surface of the lower portion. The recess accommodates a protruding portion or component of the engine. The tank also comprises a sloping surface that extends between the upper portion and the lower portion inside the tank. Lubricant is returned in the upper portion and transferred to the lower portion through a zigzag flow path.
Patent Number: 6,848,529 Issued on 02/01/2005 to Moriyama
| Inventors:
|
Moriyama; Takashi (Shizuoka, JP)
|
| Assignee:
|
Yamaha Hatsudoki Kabushiki Kaisha (Shizuoka, JP)
|
| Appl. No.:
|
151464 |
| Filed:
|
May 16, 2002 |
Foreign Application Priority Data
| May 16, 2001[JP] | 2001-146799 |
| Current U.S. Class: |
180/291; 123/196R; 180/190; 440/88L |
| Intern'l Class: |
B60K 008/00 |
| Field of Search: |
180/291,190,309,294,830,297,68.1,68.2,180,181,182
123/196 A,196 R,198 C,516,515,517,518,519,520,196,196 E,184.21,41.54,41.1,41.33
440/88 L,88 R,89 R,33,87
114/55.51
184/6.5,106,104.3,105.1
|
References Cited [Referenced By]
U.S. Patent Documents
| 3871460 | Mar., 1975 | Douglas | 180/190.
|
| 4008777 | Feb., 1977 | Juto et al. | 180/182.
|
| 4766860 | Aug., 1988 | Abe et al. | 123/196.
|
| 4848503 | Jul., 1989 | Yasui et al. | 180/190.
|
| 4892164 | Jan., 1990 | Yasui et al. | 180/68.
|
| 5040503 | Aug., 1991 | Schwabe et al. | 123/198.
|
| 5094638 | Mar., 1992 | Kobayashi | 440/33.
|
| 5117932 | Jun., 1992 | Kurosu et al. | 180/68.
|
| 5152365 | Oct., 1992 | Aoshima | 180/68.
|
| 5174258 | Dec., 1992 | Tanaka | 123/198.
|
| 5282437 | Feb., 1994 | Avillez de Basto | 114/345.
|
| 5839930 | Nov., 1998 | Nanami et al.
| |
| 5879211 | Mar., 1999 | Koyanagi.
| |
| 5899779 | May., 1999 | Hattori.
| |
| 5951342 | Sep., 1999 | Ozawa et al.
| |
| 5951343 | Sep., 1999 | Nanami et al.
| |
| 6015320 | Jan., 2000 | Nanami.
| |
| 6247442 | Jun., 2001 | Bedard et al. | 123/198.
|
| 6415759 | Jul., 2002 | Ohrnberger et al. | 123/198.
|
| 6418887 | Jul., 2002 | Okamoto | 123/41.
|
| 6447351 | Sep., 2002 | Nanami | 123/516.
|
| 6464033 | Oct., 2002 | Izumi et al. | 180/291.
|
| 6475046 | Nov., 2002 | Muramatsu et al. | 123/196.
|
| 6508211 | Jan., 2003 | Asano | 123/41.
|
| 6537115 | Mar., 2003 | Suganuma et al. | 123/198.
|
| 6544084 | Apr., 2003 | Nanami | 114/55.
|
| 6551153 | Apr., 2003 | Hattori | 440/87.
|
| Foreign Patent Documents |
| 04-135920 | Nov., 1992 | JP | .
|
Primary Examiner: Phan; Hau
Attorney, Agent or Firm: Knobbe, Martens, Olson & Bear LLP
Claims
What is claimed is:
1. A snowmobile comprising a frame assembly having a forward portion, a
forward body cover disposed over the forward portion of the frame
assembly, the forward body cover at least partially defining an engine
compartment, an engine being mounted in the engine compartment, the engine
comprising an engine body defining a cam shaft chamber and a crankcase
chamber, an auxiliary component protruding laterally of the engine body,
the engine further comprising a crankshaft that extends generally
transverse to a generally vertical longitudinal center plane of the frame
assembly, a lubricant tank comprising a forward portion and a rearward
portion and being mounted within the engine compartment on a lateral side
of the engine body.
2. The snowmobile of claim 1, wherein the lubricant tank further comprises
a recess portion located on the side of the lubricant tank that faces the
engine body when the lubricant tank is mounted in the engine compartment,
the recess portion receiving at least a portion of the auxiliary
component.
3. The snowmobile of claim 2, wherein the recess portion is located
adjacent a lower portion of the lubricant tank.
4. The snowmobile of claim 1, further comprising a brake assembly located
generally rearward of the lubricant tank, a ventilation opening defined in
the forward body cover, an engine compartment exhaust port located
generally rearward of the brake assembly, the ventilation opening and the
engine compartment exhaust port communicating with the atmosphere and the
engine compartment, and an airflow path extending between the ventilation
opening and the engine compartment exhaust port such that the airflow
passes the lubricant tank and the brake assembly.
5. The snowmobile of claim 4, further comprising a breather pipe connection
port located on an upper portion of the lubricant tank at a location
offset toward a lateral side of the snowmobile and a breather pipe, the
breather pipe having a first end connected to the breather pipe connection
port and a second end connected to at least one of the cam shaft chamber
and the crankcase chamber.
6. The snowmobile of claim 5, wherein the lubricant tank further comprises
an expansion portion, a recess portion, a shelf extending between the
expansion portion and the recess portion, a lubricant supply port located
proximate a lower portion of the lubricant tank, and a lubricant return
port at an elevation above the shelf, lubricant entering the tank through
the lubricant return port being directed onto the shelf before returning
to the lower portion of the lubricant tank.
7. The snowmobile of, claim 6, wherein the lubricant tank further comprises
a drain formed at the bottom of the lubricant tank for removing the
lubricant from the lubricant tank.
8. The snowmobile of claim 6, wherein the lubricant tank further comprises
an inside surface, an outside surface, and a guide secured to the inside
surface of the lubricant tank, the guide being positioned between the
lubricant return port and the shelf.
9. A snowmobile comprising a frame assembly, an engine positioned above a
portion of the frame assembly, the engine comprising an engine body, the
engine body comprising a crankcase member, a cylinder block and a cylinder
head, a crankcase chamber being partially defined by the crankcase member,
a crankshaft extending through the crankcase, the crankshaft extending a
transverse direction relative to a general direction of movement of the
snowmobile, a lubricant tank being disposed to one lateral side of the
engine such that a rotational axis of the engine intersects a portion of
the lubricant tank, the lubricant tank comprising an enlarged upper
portion and a reduced lower portion, the upper portion and the lower
portion sharing at least one surface such that a recess region is defined
below a portion of the upper portion and to a side of the lower portion, a
lubricant return port being located in the upper portion of the lubricant
tank and a guide being located in the lubricant tank generally below the
lubricant return port, the lubricant tank further comprising a baffle that
is disposed vertically lower than the guide and that is positioned
generally to one side of the guide at a position within the lower portion
of the lubricant tank.
10. The snowmobile of claim 9, wherein the lubricant tank comprises an
outer surface that comprises two portions joined together at a flange, the
flange being positioned in a generally vertical longitudinal plane that is
generally parallel to and offset from a generally vertical longitudinal
center plane of the snowmobile.
11. The snowmobile of claim 9, wherein the guide comprises a mounting rim
affixed to an inner surface of the lubricant tank and a downturned spout.
12. The snowmobile of claim 11, wherein the guide further comprises a
generally planar portion that extends between the mounting rim and the
downturned spout.
13. The snowmobile of claim 9, wherein the baffle comprises a plate, a
mounting portion connected to the plate and at least one passage extending
through the plate.
14. The snowmobile of claim 13 further comprising a sensor that extends
through the at least one passage in the baffle.
15. The snowmobile of claim 14, wherein the sensor is mounted to a boss
formed in the upper portion of the lubricant tank.
Description
RELATED APPLICATIONS
This application is based upon and claims the priority of Japanese Patent
Application No. 2001-146799, filed on May 16, 2001, which is hereby
incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a lubrication system for land
vehicles. More specifically, the present invention relates to an improved
lubrication system for snowmobiles that can be accommodated in a smaller
engine compartment.
2. Description of the Related Art
A snowmobile is a land vehicle that is propelled by a drive belt generally
centered on a vertical longitudinal central plane. A pair of snow skis are
arranged generally forward of the drive belt at locations generally
laterally off-set on either side of the vertical longitudinal central
plane. An internal combustion engine is coupled to the drive belt to drive
the snowmobile over uneven terrain, sometimes at relatively high speeds.
The snowmobile engine is generally mounted within a substantially enclosed
engine compartment forward of the rider's seat. The engine compartment
typically is defined within a cowling and is generally relatively small.
The snowmobile engine has a lubrication system that reduces friction
between the moving parts of the engine and thereby reduces heat that is
generated by friction during the operation of the engine. Many such
engines are dry-sump engines. In other words, the lubrication system of
the engine includes a lubricant tank that stores the lubricant that is not
circulating through the engine. The lubricant tank is generally positioned
within the engine compartment at a location forward of the engine.
Unfortunately, locating the lubricant tank forward of the engine requires
a larger engine compartment to house the engine and the lubricant tank.
In addition to being mounted longitudinally forward of the engine, the
lubricant tank usually has a short and wide profile. In other words, the
height (i.e., the vertical dimension of the lubricant tank) is small
compared to the longitudinal horizontal dimension (i.e., the dimension of
the lubricant tank along a line in or parallel to the vertical
longitudinal central plane) and the height is small compared to the
transverse horizontal dimension (i.e., the dimension of the lubricant tank
along a line transverse, or perpendicular to the vertical longitudinal
central plane). Stated another, way, the horizontal cross-sectional area
of the lubricant tank is relatively large while the vertical
cross-sectional area of the lubricant tank is relatively small. This is
disadvantageous because lubricant sloshing caused by the uneven terrain
and relatively high speed of the snowmobile can cause air to be entrained
with the lubricant, which degrades the performance of the lubrication
system.
SUMMARY OF THE INVENTION
Thus, a snowmobile having an engine with a lubrication system that has a
lubricant tank that is compactly arranged and that tends to reduce
entrained air in the lubricant is desired.
Accordingly, one aspect of the present invention involves a snowmobile that
includes a frame assembly that has a forward portion, a forward body
cover, an engine, and a lubricant tank. The forward body cover is disposed
over the forward portion of the frame assembly. The forward body cover at
least partially defines an engine compartment. The engine, which is
mounted in the engine compartment generally transversely to the frame
assembly, includes a cam shaft chamber, a crankcase chamber, and a
laterally extending component. The lubricant tank has a forward portion
and a rearward portion. The lubricant tank is mounted within the engine
compartment on a lateral side of the engine.
Another aspect of the present invention involves a lubricant tank for a
lubrication system of an engine. The lubricant tank has an upper portion
and a lower portion. The lubricant tank also has a lubricant return port,
a guide, and a baffle. The lubricant return port is located in the upper
portion of the lubricant tank. The guide is located within the lubricant
tank at an elevation below the lubricant return port. The lubricant return
port and the guide are positioned such that lubricant that enters the
lubricant tank through the lubricant return port drips onto the guide. The
baffle is located at an elevation below the guide. The guide directs the
lubricant toward the baffle.
Another aspect of the present invention involves a lubricant level
monitoring system for a snowmobile engine lubrication system. The system
includes a lubricant tank, a non-operating lubricant level gauge, and an
operating lubricant level sensor. The lubricant tank has a non-operating
lubricant level gauge boss and an operating lubricant level sensor boss.
The non-operating lubricant level gauge, which is insertable into the
lubricant level gauge boss of the lubricant tank, indicates the level of
the lubricant in the lubricant tank when the engine is not running. The
operating lubricant level sensor, which is insertable into the operating
lubricant level sensor boss, collects lubricant level data while the
engine is operating and provides an alarm if the lubricant level is too
low.
A further aspect of the present invention involves a snowmobile comprising
a frame assembly having a forward portion. A forward body cover is
disposed over the forward portion of the frame assembly with the forward
body cover at least partially defining an engine compartment. An engine is
mounted in the engine compartment with the engine comprising an engine
body defining a cam shaft chamber and a crankcase chamber. An auxiliary
component protrudes laterally of the engine body. The engine further
comprises a crankshaft that extends generally transverse to a generally
vertical longitudinal center plane of the frame assembly. A lubricant tank
comprises a forward portion and a rearward portion and is mounted within
the engine compartment on a lateral side of the engine body.
An additional aspect of the present invention involves a snowmobile
comprising a frame assembly and an engine positioned above a portion of
the frame assembly. The engine comprises an engine body that itself
comprises a crankcase member, a cylinder block and a cylinder head. A
crankcase chamber is partially defined by the crankcase member and a
crankshaft extends through the crankcase. The crankshaft extends in a
transverse direction relative to a general direction of movement of the
snowmobile. A lubricant tank is disposed to a lateral side of the engine
such that a rotational axis of the engine intersects a portion of the
lubricant tank. The lubricant tank comprises an enlarged upper portion and
a reduced lower portion. The upper portion and the lower portion share at
least one surface such that a recess region is defined below a portion of
the upper portion and to a side of the lower portion. A lubricant return
port is located in the upper portion of the lubricant tank and a guide is
located in the lubricant tank generally below the lubricant return port.
The lubricant tank further comprises a baffle that is disposed vertically
lower than the guide and that is positioned generally to one side of the
guide at a position within the lower portion of the lubricant tank.
One other aspect of the present invention involves a snowmobile comprising
a frame assembly. At least one ski is connected to the frame assembly. An
engine is mounted to the frame assembly. A lubricant tank is positioned to
a side of the engine. The lubricant tank comprises means for directing
returning lubricant to a collecting position in the lubricant tank and the
lubricant tank further comprises a recess that accommodates a laterally
protruding portion of the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects and advantages of the present invention
will be better understood with reference a preferred embodiment, which is
illustrated in the accompanying drawings. The illustrated embodiment is
merely exemplary and is not intended to define the outer limits of the
scope of the present invention. The drawings of the illustrated
arrangement comprise thirteen figures.
FIG. 1 is a side elevation view of the snowmobile with certain portions
broken away and other internal portions shown in hidden line to better
illustrate certain features, aspects and advantages of the present
invention.
FIG. 2 is a top plan view of the snowmobile of FIG. 1 with certain internal
portions shown in hidden line.
FIG. 3 is a front elevation view of the snowmobile of FIG. 1.
FIG. 4 is a schematic top, front, and side perspective view of an engine of
the snowmobile of FIG. 1.
FIG. 5 is a side elevation view of one embodiment of a lubricant tank
showing an outwardly facing side of the lubricant tank.
FIG. 6 is a side elevation view of the lubricant tank of FIG. 5 showing an
inwardly facing side of the lubricant tank.
FIG. 7 is a front elevation view of the lubricant tank of FIG. 5 showing a
forward portion of the lubricant tank.
FIG. 8 is a top view of the lubricant tank of FIG. 5 showing an upper
portion of the lubricant tank.
FIG. 9 is a bottom view of the lubricant tank of FIG. 5 showing a lower
portion of the lubricant tank.
FIG. 10 is a side elevation view of the inwardly facing side of one
embodiment of a lubricant tank, with portions shown in hidden lines to
better illustrate certain features, aspects and advantages of the present
invention.
FIG. 11 is a rear elevation view of the lubricant tank of FIG. 10 with
portions shown in hidden lines to better illustrate certain features,
aspects and advantages of the present invention.
FIGS. 12A-12C illustrate one embodiment of a guide incorporated into some
embodiments of the lubricant tank described herein. FIG. 12A is a top plan
view of the guide. FIG. 12B is a side view of the guide of FIG. 12A taken
from the side indicated by the arrows 12B--12B. FIG. 12C is a side view of
the guide of FIG. 12A taken from the side indicated by the arrows
12C--12C.
FIGS. 13A--13B illustrate one embodiment of a baffle that is incorporated
into some embodiments of the lubricant tank described herein. FIG. 13A is
a top plan view of one embodiment of a baffle. FIG. 13B is a side view of
the baffle of FIG. 13A taken from the side indicated by arrows 13B--13B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to FIG. 1, a snowmobile having certain features, aspects
and advantages of the present invention will be described. The snowmobile,
indicated generally by the reference numeral 20, is an environment for
which many features, aspects and advantages of the present invention have
been specially adapted. Nevertheless, certain features, aspects and
advantages of the present invention can be used with other vehicles, such
as all-terrain vehicles and watercraft.
The snowmobile 20 generally comprises a frame assembly 22 that carries a
number of other components of the snowmobile 20. With reference to FIG. 2,
the frame assembly 22 and many of the components positioned relative
thereto are arranged along a vertical longitudinal central plane ("VLCP").
A forward body cover 24 is disposed over a forward portion of the frame
assembly 22. The forward body cover 24 defines, in part, an engine
compartment 26 in which an engine 28 is mounted. The engine 28 will be
described in greater detail below in connection with FIG. 4.
A windshield 30 is disposed over a mid-portion of the illustrated body
cover 24. The windshield 30 provides some degree of protection for the
riders from wind and other elements during operation of the snowmobile 20.
Rearward of the windshield 30, a fuel tank 32 is mounted to the frame
assembly 22 in a manner that allows the body cover 24 and the fuel tank 32
to blend together.
Rearward of the fuel tank 32, a seat 34 is mounted to the frame assembly
22. Rearward of the seat 34 is positioned a grab bar 39 that comprises a
grabbing portion 41 that can be used to raise a rear portion of the
snowmobile for turning and maneuvering when the snowmobile is not being
ridden. While the illustrated grab bar 39 is generally U-shaped and is
mounted in a generally horizontal manner, other forms of grab bars can be
used. For instance, the grab bar 39 can be loops, semicircular, vertical
or inclined in orientation. In short, any suitable grab bar construction
can be used.
Forward of the seat 34 and the fuel tank 32 is a steering handle assembly
42. The steering handle assembly 42 can carry appropriate controls and can
be coupled to a pair of front skis 44. Manipulation of the steering handle
assembly 42 causes the direction of the snowmobile 20 to be altered. The
front skis 44 are mounted to the frame assembly 22 though a front
suspension assembly 46. Any suitable front suspension assembly 46 can be
used.
The engine 28 in the illustrated arrangement is an inclined L-4 four-cycle
engine that is mounted transversely within the engine compartment 26. In
other words, the illustrated engine 28 comprises four cylinder bores that
extend side-by-side across a width of a cylinder block 47, that extends
across a width of the snowmobile 20. The cylinder bores each comprise a
center axis O (see FIG. 1) that is inclined relative to vertical. In some
arrangements, engines having differing numbers of cylinder bores,
different cylinder block configurations (e.g., V, opposing, double V or W
etc.), different orientations (e.g., vertical) and different operating
principles (e.g., two-stroke, rotary, etc.) can be used.
With reference to FIGS. 1 and 4, the engine 28 also comprises an output
shaft 50 that drives a transmission, which is a continuously variable
transmission 52 in the illustrated arrangement. Other transmissions also
can be used. In the illustrated arrangement, the output shaft 50 rotates a
drive pulley 54. The output shaft 50 and the drive pulley 54 can be
connected together through a clutch, a centrifugal clutch, a sprag clutch
(one-way clutch) or can be directly connected together.
The drive pulley 54 powers a driven pulley 56 with a v-belt 58 in the
illustrated arrangement. In some configurations, a drive chain can be used
in place of the v-belt 58. Other arrangements also can be used. The driven
pulley 56 is connected to and rotates with a transfer shaft 60 about a
transfer axis. In the illustrated arrangement, the transfer shaft 60
carries a sprocket (not shown) at the end opposite to the driven pulley
56. The sprocket is connected to a further sprocket that is carried by a
drive shaft 62.
The drive shaft 62 powers a drive unit 64. The drive unit 64 generally
comprises a plurality of drive wheels 68. The drive wheels 68 provide a
motive force to a drive belt 70, which is commonly used in the snowmobile
industry.
With continued reference to FIG. 1, the drive belt 70 is guided around a
preferred path on a pair of slide rails 72, a plurality of suspension
wheels 74 and main rear suspension wheels 76. The slide rails 72
preferably support the suspension wheels 74 and the main rear suspension
wheels 76. An idler roller 78 preferably is mounted to the frame assembly
22 and helps to define the preferred path for the drive belt 70. As is
known in the snowmobile industry, these components can be mounted to the
frame assembly with a rear suspension system 80. Any suitable rear
suspension system 80 can be used and certain portions of the rear
suspension system 80 have been schematically illustrated in the
illustrated arrangement.
Many of the above-described components are conventional and can be arranged
and configured in any suitable manner. Additionally, the above-described
components can be replaced by other suitable components where desired. Any
details omitted to this point have been considered well within the design
knowledge of those of ordinary skill in the art.
With continued reference to FIG. 1, air is drawn into the engine
compartment 26 through suitable air passages formed in, through and/or
around the body cover 24. In some arrangements, the air is drawn through
ventilation openings 90 formed in the body cover 24. The air drawn or
forced into the engine compartment 26 through the passages circulates
about the engine 28 and the related drive components to help cool the
engine 28 and the related drive components. As discussed in more detail
below in connection with FIG. 2, air also can be drawn or forced into the
engine compartment 26 through at least one side ventilation opening 91.
The side ventilation openings 91 are generally laterally off-set from the
VLCP. In one particularly preferred arrangement, the side ventilation
openings a laterally offset from the cylinder block 47 (see FIG. 1).
Some air from within the engine compartment 26 is drawn into an air intake
box 92. The air intake box 92 is disposed forward of the engine 28 in the
illustrated arrangement. The air intake box 92 can be mounted to the frame
assembly 22 in a manner that will be described. An air inlet 93 into the
air intake box 92 can extend upward into a lower surface of the air intake
box 92.
A set of intake runners 94 extends between the illustrated air intake box
92 and the engine 28. Preferably, a charge former 96 is disposed along
each of the intake runners 94. Advantageously, the intake runners 94
extend directly rearward to the engine 28 rather than wrapping around the
engine 28 and mating with a rearward-facing surface of the engine 28. The
charge formers 96 preferably correspond to each cylinder bore. In some
arrangements, a single charge former can be used upstream of a separation
point for runners extending to individual cylinder bores. In addition, in
the illustrated arrangement, the engine 28 is carbureted. In some
arrangements, the charge formers 96 can be fuel injectors that are mounted
for direct injection, indirect injection or port injection. The air-fuel
charge provided in this manner is combusted within the engine.
The combustion byproducts then are exhausted through a suitable exhaust
system 100. In the illustrated arrangement, the exhaust system 100 extends
directly rearward from the engine 28. In this manner, an exhaust runner
102 that extends rearward from the engine can be tuned to the engine for
improved engine performance. Additionally, the length of each runner 102
can be lengthened prior to merging together with any other runners such
that pulse effects on adjoining cylinder bores can be reduced. In some
arrangements, an attenuation chamber or passage between two or more
runners can be used to reduce the effect of reflected pressure pulses in
the exhaust system.
With continued reference to FIG. 1, the exhaust system 100 preferably
comprises the exhaust runners 102 that correspond to each cylinder bore
and that extend generally rearward from the engine 28. Each exhaust runner
102 is coupled to an exhaust discharge pipe 106 that is individually
joined to the engine 28 in the illustrated arrangement. In some
arrangements, a single manifold can be used. In the illustrated
arrangement, at least two of the runners 102 join at a merge location (not
shown) and the merged flow passes through a manifold pipe 116.
The manifold pipes 116 extend rearward to a silencer box 118. The silencer
box 118 provides an enlarged volume into which the exhaust can flow.
Exhaust energy is dissipated within the silencer box 118 and the noise
level of the exhaust can be decreased. In the illustrated arrangement, the
silencer box 118 is disposed below a portion of the seat 34 that is
rearward of a rider section 121 of the seat.
A pair of exhaust pipes 120 extends rearward from the silencer box 118. In
some arrangements, a single exhaust pipe 120 can extend from the silencer
box 118. Other numbers of exhaust pipes also can be used. One end of each
of the exhaust pipes 120 preferably defines an ultimate exhaust discharge
122 from the snowmobile 20 such that the exhaust gases are discharged into
the atmosphere at this location. As illustrated in FIG. 1, the exhaust
pipes 120 can extend upwardly and rearwardly from the silencer box 118
while, in another arrangement, shown in hidden lines, the exhaust pipes
120 can extend downward to a location forward of a protective flap 124.
Preferably, the exhaust pipes 120 terminate at a location forward of the
grab portion 41 of the grab bar 39.
With reference to FIG. 2, the snowmobile 20 includes, in one embodiment, a
brake assembly 140 located generally rearward of the ventilation opening
91 and one or more engine compartment exhaust ports 144 located generally
rearward of the brake assembly 140. As discussed in more detail below,
some of the air that enters the engine compartment through the side
ventilation opening 91 flows over at least a portion of the brake assembly
140 to the engine compartment exhaust ports 144 and is discharged
therethrough to the atmosphere. This discharge location allows heated air
to be directed generally toward an operator of the snowmobile.
With reference now to FIGS. 1 and 4, the engine 28 of the illustrated
snowmobile 20 will be described in greater detail. The engine 28 includes
the cylinder block 47 that defines four combustion bores (not shown)
spaced from each other transversely across the snowmobile 20. As discussed
above, each of the cylinder bores has a cylinder bore axis O that is
slanted or inclined at an angle from a vertical plane that is transverse
to the snowmobile 20 so that the engine 28 can be shorter in height.
Pistons (not shown) reciprocate within the cylinder bores. A cylinder head
216 is affixed to the upper end of the cylinder block 47 to close
respective upper ends of the cylinder bores and thus define combustion
chambers (not shown) with the cylinder bores and the pistons.
Intake and exhaust valves are operated in coordination with the pistons to
provide air/fuel charges and to remove burnt charges from the combustion
chambers respectively. The valves are driven by a suitable valvetrain,
such as a double overhead cam-type valvetrain. In such an arrangement, an
intake cam shaft actuates the intake valves and an exhaust cam shaft
separately actuates the exhaust valves. The intake cam shaft extends
generally horizontally over the intake valves transversely across to the
VLCP of the snowmobile 20, and the exhaust cam shaft extends generally
horizontally over the exhaust valves transversely across the VLCP of the
snowmobile 20.
Both the intake and exhaust cam shafts are journaled by the cylinder head
member 216 with a plurality of cam shaft caps (not shown). The cam shaft
caps holding the cam shafts are affixed to the cylinder head member 216. A
cylinder head cover member 219 extends over the cam shafts and the cam
shaft caps, and is affixed to the cylinder head member 216 to define a cam
shaft chamber 221. The intake and exhaust cam shafts are arranged to
actuate the intake and exhaust valves in a suitable manner.
With reference to FIG. 4, a crankcase member 224 is affixed to the lower
end of the cylinder block 47 to define a crankcase chamber 226. A
crankshaft 228 is rotatably connected to the pistons in a conventional
manner. The crankshaft 228 is journaled in the crankcase member 224 by
bearings (not shown). A crankshaft cover 232 that covers an end of the
crankshaft 228 and associated components is provided on a lateral side of
the crankcase member 224. Rotation of the crankshaft 232 drives the output
shaft 50 in any suitable manner. An auxiliary shaft 236 is also journaled
in the crankcase member 224 and is rotatably coupled to the crankshaft 228
in a suitable manner. The auxiliary shaft 236 powers a lubricant pump that
is at least partially housed within a lubricant pump housing 240. The
lubricant pump circulates lubricant in a lubrication system. The terms
"oil" and "lubricant" (and variations thereof) are used interchangeably
herein, and are intended to mean a lubricant material such as natural
petroleum oil, synthetic oil and other materials as known to those skilled
in the art for use in lubricating an engine.
The auxiliary shaft 236 also powers a coolant pump that is at least
partially housed within a coolant pump housing 244. The coolant pump
housing 244 is enclosed by a coolant pump housing cover 248. The coolant
pump circulates coolant through a cooling system.
The cylinder block 47, the cylinder head member 216, the crankshaft cover
232 and the crankcase member 224 together define an engine body 236. The
engine body 236 preferably is made of an aluminum-based alloy. In the
illustrated embodiment, the engine body 236 is oriented in the engine
compartment 26 so as to position the crankshaft 228 generally
perpendicular to the VLCP of the snowmobile 20 such that the crankshaft
228 extends generally in the transverse direction. Other orientations of
the engine body 232, of course, are also possible (e.g., with a
longitudinal or vertically-oriented crankshaft 228).
The engine operation is described more fully in Applicant's copending U.S.
application Ser. No. 10/094,748, filed Mar. 8, 2002, incorporated herein
by reference in its entirety.
The engine 28 includes a variety of sub-systems, including an ignition
system, the lubrication system, and the cooling system. With reference to
FIG. 4, spark plugs 252, at least one for each of the combustion chambers,
are affixed to the cylinder head member 216 so that electrodes, which are
defined at one end of the spark plugs 252, are exposed to the respective
combustion chambers. The spark plugs 252 preferably are fired in a
conventional manner. The air/fuel charge is thereby combusted during every
combustion stroke accordingly.
The engine 28 also includes other components relating to engine operations.
With reference to FIG. 4, the engine 28 employs a flywheel magneto or AC
generator. The flywheel magneto generates electric power that is used for
the engine operation as well as for electrical accessories associated with
the snowmobile 20. In one embodiment, the flywheel magneto is located on
one lateral side of the engine 28 and is enclosed by a flywheel magneto
housing 256. Thus, the flywheel magneto or the flywheel magneto housing
256 are laterally extending components of the engine 28. Of course other
components of the engine 28 could be located proximate a lateral edge of
the engine 28 and could thus be laterally extending components of the
engine 28. A starter motor 248 (FIG. 2) rotates the crankshaft 228 for
starting the engine 28 in a manner well known to those of ordinary skill
in the art. The starter motor may be powered by a battery, which can be
charged by the generator.
The coolant system of the engine 28 includes the coolant pump, discussed
above, and a coolant conduit 276 that connects the coolant pump to the
engine body 236. In addition to the coolant conduit 276, a series of
additional conduits provide fluid communication between the engine body
236, at least one heat exchanger, and other components that typically are
maintained below a desired temperature.
The lubrication system of the engine 28 includes the lubricant pump,
discussed above, a lubricant cooler 260, a lubricant filter 264, and a
lubricant tank 268. The lubricant pump circulates lubricant through the
engine 28, through the lubricant cooler 260, through the lubricant filter
264, and returns the lubricant to the lubricant tank 268.
The lubricant cooler 260 includes a heat exchanger. Lubricant that enters
the lubricant cooler 260 flows through the heat exchanger and is cooled
therein. Fluid communication is provided between the lubricant cooler 260
and the lubricant filter 264, e.g., via one or more lubricant passages.
Thus, lubricant is directed from the lubricant cooler 260 to the lubricant
filter 264. The lubricant filter 264 removes debris from the lubricant.
In one embodiment, the lubricant tank 268 has an upper portion 269 into
which lubricant returns after circulating through the engine 28, a lower
portion 270 where at least a portion of the lubricant is housed, and a
plurality of ports, discussed more fully below, for ingress and egress of
the lubricant. The lubricant tank 268 also includes at least one mounting
boss that receives a lubricant level sensing component, discussed more
fully below.
The lubricant tank 268, illustrated in dashed lines in FIG. 4, is
preferably configured to reside very close to a lateral side of the engine
28. In one embodiment, the configuration of the upper portion 269 and the
lower portion 270 are such that one or more laterally extending components
of the engine 28, i.e., one or more components that protrude laterally
from a side surface of the engine body 236, can be accommodated in a
recess portion 271 at least partially defined by the upper portion 269 and
the lower portion 270 of the lubricant tank 268. In the illustrated
arrangement, the lower portion 270 has a reduced horizontal cross-section
relative to the upper portion 269 such that the recess portion 271 is
defined by the two portions. By providing the recess portion 271, the
lubricant tank 268 and the engine 28 can be arranged more compactly within
the engine compartment 26. A compact arrangement of components thus
provided advantageously results in a smaller overall vehicle body,
additional space in the engine compartment 26 for other components, or
other advantages that will be apparent to one skilled in the art from the
description herein.
With reference to FIG. 2, the lubricant tank 268 has a forward portion 272
and a rearward portion 273. The lubricant tank 268 is located generally
between the ventilation opening 91 and the engine compartment exhaust
ports 144. An airflow path generally indicated by the arrows labeled "A"
is defined within the engine compartment 26 during movement of the
snowmobile. In some arrangements, a cooling fan can be used to draw air
along the airflow path.
The ventilation opening 91, as discussed above, is defined in the forward
body cover 24 to admit air into the engine compartment 26. The engine
compartment exhaust ports 144 are located generally rearward of the brake
assembly 140. The engine compartment exhaust ports 144 communicate with
the atmosphere. In one embodiment, the airflow path, indicated by the
arrows labeled "A", extends between the side ventilation opening 91 and
the forward portion 272 of the lubricant tank 268. In another embodiment,
the airflow path extends between the ventilation opening 90 and the
forward portion 272 of the lubricant tank 268. The airflow path indicated
by the arrows labeled "A" further extends between the rearward portion 273
of the lubricant tank 268 and the brake assembly 140. The airflow path
indicated by the arrow "A" further extends between the brake assembly 140
and the engine compartment exhaust ports 144.
This arrangement provides several advantages. For example, each of the
ventilation opening 91, the lubricant tank 268, the brake assembly 140,
and the engine compartment exhaust ports 144 are off-set from the VLCP of
the snowmobile 20. More generally, these components are located at one or
more lateral positions between the lateral-most extending component of the
engine 28 and the lateral-most portion of the snowmobile 20. Thus, these
components do not require the longitudinal dimension of the engine
compartment 26 or the snowmobile 20 to be increased to accommodate them.
In addition, the lubricant tank 268 and the brake assembly 140 are cooled
by the relatively low temperature of the airflow between the ventilation
openings 90, 91 and the engine compartment exhaust ports 144. A further
benefit is provided in that heat exchange between the lubricant tank 268
and the airflow and between the brake assembly 140 and the airflow
increases the temperature of the airflow downstream of the lubricant tank
268 and downstream of the brake assembly 140. As a result, the airflow
exiting the engine compartment 26 through the engine compartment exhaust
ports 144 may be warm enough to warm the leg of the rider. This increases
the comfort of the rider in the cold environment in which the snowmobile
20 is operated.
With reference now to FIGS. 5-13, various features of the lubricant tank
268 will be described in greater detail. In the illustrated embodiment,
the lubricant tank 268 includes a first lateral portion 304, a second
lateral portion 308, a flange 312, and a mounting bracket 316. The first
lateral portion 304 and the second lateral portion 308 preferably are
joined at the flange 312. The first lateral portion 304 and the second
lateral portion 308 at least partially defining a volume for housing
lubricant within the lubricant tank 268. In the illustrated embodiment,
the lubricant tank 268 is mounted in the engine compartment 26, e.g.,
mounted to the engine 28, by the bracket 316. One skilled in the art will
recognize that the bracket 316 could also mount the lubricant tank 268 to
the frame 22 of the snowmobile 20, or any other suitable component in the
engine compartment 26.
As discussed above, in connection with the engine 28 of FIG. 4, one
embodiment of the lubricant tank 268 can be mounted proximate the engine
28, spaced laterally outwardly therefrom. The lubricant tank 268 can be
configured to accommodate at least a portion of one or more laterally
extending components of the engine 28. This construction of the lubricant
tank 268 and the engine 28 is advantageous because it provides a more
compact combination of the engine 28 and the tank 268, which enables the
engine compartment 26 to be made smaller or provides space for other
components therein.
The first lateral portion 304 preferably is the portion that resides
farthest laterally from the VLCP of the snowmobile 20 when the lubricant
tank 268 is mounted in the engine compartment 26. The first lateral
portion 304 comprises a lubricant supply port 320 and a lubricant drain
324. The lubricant drain 324 provides an outlet for the lubricant tank 268
through which the lubricant that is housed in the lubricant tank 268 can
be removed from the lubrication system for replacement, for testing, or
for any other purpose. The lubricant supply port 320 provides an outlet
for lubricant that is housed in the lubricant tank 268. Lubricant that
passes through the lubricant supply port 320 enters the series of
lubricant passages of the engine 28 and is thereby provided to the various
moving components of the engine 28. After being supplied to the various
moving components of the engine 28, the lubricant is returned to the
lubricant tank 268 through another series of passages for further
circulation in the lubrication system.
Preferably the lubricant tank 268 has a generally vertically elongated
shape. In other words, the height H of the lubricant tank 268 (i.e., the
vertical dimension) is relatively large compared to the longitudinal
horizontal dimension D1 of the lubricant tank 268 (i.e., the dimension
along a horizontal plane parallel to the VLCP). See FIGS. 2 and 5. The
height H of the lubricant tank 268 is large compared to the transverse
horizontal dimension D2 of the lubricant tank 268 (i.e., the dimension
along a line transverse, or perpendicular to the VLCP). See FIGS. 3 and 7.
This configuration provides a lubricant tank 268 having a horizontal
cross-sectional area that is relatively small and having a lubricant
column within the lubricant tank 268 that is relatively tall. This
arrangement advantageously increases the space between the top of the
lubricant column and the lubricant supply port 320. By increasing the
spacing between the top of the lubricant column and the lubricant supply
port 320, the gases in the lubricant tank 268 are much less likely to be
entrained in the lubrication system.
In some embodiments, the lubricant tank 268 also provides a plurality of
lubricant level sensing components. With reference to FIGS. 5 and 11, the
first lateral portion 304 of the lubricant tank 268 includes a lubricant
level gauge boss 328 and a lubricant level sensor boss 329. The lubricant
level gauge boss 328 provides an aperture into which a lubricant level
gauge 330 can be inserted and retained during operation of the snowmobile
20. The lubricant level gauge 330 visually indicates how much lubricant is
in the lubricant tank 268 and thereby indicates the amount of lubricant
being circulated through the lubrication system of the engine 28. The
lubricant level within the lubricant tank 268 varies depending upon
whether the engine 28 is or is not running, among other factors. As can be
seen in FIG. 11, when the engine 28 is stopped, the lubricant preferably
resides at a lubricant level L.sub.S. The length of the lubricant level
gauge 330 is determined, in part, by the expected lubricant level L.sub.S.
As is known, the lubricant level gauge 330 is configured to be long enough
to extend beyond the expected non-operating lubricant level L.sub.S and to
have a series of graduation markings that indicate the actual lubricant
level L.sub.S compared to the expected lubricant level L.sub.S.
The lubricant level sensor boss 329 provides an aperture into which a
lubricant sensor 332 can be inserted. This lubricant level sensor 332
gathers data relating to the volume of lubricant in the tank while the
engine 28 is running. These data are processed in a suitable manner to
provide an alarm or warning to the user during operation of the snowmobile
20 when the lubricant level is too low. As can be seen in FIG. 11, when
the engine 28 is running, a lubricant level L.sub.R results. The lubricant
level L.sub.R may vary depending upon the angular speed of the engine and
other factors. The length of the lubricant sensor 332 is determined, in
part, by the expected lubricant level L.sub.R during the highest lubricant
demand condition (e.g., highest angular speed). In general, the lubricant
level sensor 332 is configured to extend much further down into the
lubricant tank 268 than the lubricant level gauge 330. In some
arrangements, two sensors can be used in which one sensor, for example
gauge 330, provides an output to an oil level display and another sensor,
for example, sensor 332, provides an output to an alarm device that will
alert an operator to a low oil operating condition.
Preferably, the sensors 332 and gauges 330 indicators are mounted on the
portion of the lubricant tank 268 that has the largest depth. By
positioning the sensors 332 and gauges 330 in this position, the increased
depth can be used to differentiate between true alarm conditions and false
alarms caused by operating conditions, such as jumps, turns, and rapid
accelerations or decelerations.
In one embodiment, the second lateral portion 308 includes an expansion
portion 336, the recess portion 271, a shelf 344, an upper surface 345,
and a lower surface 346. Both the upper surface 345 and the lower surface
346 face the engine 28 when the illustrated lubricant tank 268 is mounted
in the engine compartment 26. The expansion portion 336 is the portion of
the lubricant tank 268 that is located generally toward the upper portion
269 and is defined, in part, between the flange 312 and the upper surface
345. The recess portion 271 is the portion of the lubricant tank 268 that
is located generally toward the lower portion 270 and is defined, in part,
between the flange 312 and the lower surface 346. In general, the lateral
distance between the flange 312 and the upper surface 345 is much greater
than the lateral distance between the flange 312 and the lower surface
346. See FIG. 7. As discussed above, the recess portion 271 accommodates,
in some embodiments, at least a portion of at least one laterally
extending component of the engine 28. Where provided, the shelf 344 is a
generally upwardly facing surface that extends between the expansion
portion 336 and the recess portion 271. The illustrated shelf 344 also
forms a surface that curves downwardly, i.e., the elevation of the end of
the shelf 344 that is closest to the forward portion 272 of the lubricant
tank 268 is higher than the elevation of the end of the shelf 344 that is
closest to the rearward portion 273 of the lubricant tank 268. In the
embodiment shown in FIGS. 6 and 7, the shelf forms a continuous curved
surface between these two ends. The slope between the ends also can be
reversed such that the forward portion is lower than the rearward portion.
The sloping allows the lubricant to gently return to the supply pool
during engine operation such that air entrainment can be reduced.
In one embodiment, the second lateral portion 308 also includes a lubricant
return port 348 and a breather pipe connection port 352. As illustrated in
FIGS. 6 and 7, the lubricant return port 348 is provided proximate the top
of the second lateral portion 308. Lubricant returns to the lubricant tank
268 through the lubricant return port 348 after circulating through the
engine 28. The lubricant that flows through the lubricant return port 348
is directed thereby generally toward in the inside surface of the
expansion portion 336 and generally toward the rearward portion 273 of the
lubricant tank 268. As discussed, where the shelf portion 344 is provided,
the lubricant is then directed downward to the shelf portion 344, which
further directs the lubricant toward the lower portion 270 of the
lubricant tank 268.
In one embodiment, the breather pipe connection port 352 is provided
proximate the top of the second lateral portion 308 of the lubricant tank
268. In another embodiment, the breather pipe connection port 352 is
provided on the first lateral portion 304 of the lubricant tank 268. In
this embodiment, when the lubricant tank 268 is mounted in the snowmobile
20, the breather pipe connection port 352 is offset t
