Abstract:
The present invention provides a motorcycle including a front wheel, a rear wheel, a frame supported by the front and rear wheels, a crankcase including a first interface portion and a first passageway exposed to the first interface portion, a reservoir located remotely from the crankcase adapted to contain a lubricant, and a transmission case supported by the frame and including a second interface portion and a second passageway exposed to the second interface portion. The second passageway is in fluid communication with the reservoir. The first interface portion is coupled to the second interface portion. The first passageway is in fluid communication with the second passageway. The first and second passageways provide fluid communication between the reservoir and the crankcase through the first and second interface portions.

Description:
RELATED APPLICATIONS 
   This application is a continuation of U.S. patent application Ser. No. 11/173,181 filed on Jul. 1, 2005, now U.S. Pat. No. 7,096,846, the entire contents of which is incorporated herein by reference. 

   FIELD OF THE INVENTION 
   This invention relates generally to motorcycles, and more particularly to motorcycle engines and transmissions. 
   BACKGROUND OF THE INVENTION 
   Lubrication systems in motorcycle engines and transmissions commonly include an oil pan defining an oil reservoir, an oil pump configured to draw oil from the reservoir, an oil return hose to return oil to the reservoir, and an oil feed hose communicating the reservoir and the inlet of the oil pump. The oil pan can be mounted remotely from the engine adjacent and below the transmission. Due to the oil pan&#39;s remote positioning from the engine, the lubrication system requires external hoses extending from the oil reservoir to the engine for providing oil to, and receiving oil from, the engine. 
   Motorcycle engines and transmissions also typically include external vent hoses communicating the crankcase of the engine and the transmission case of the transmission. 
   SUMMARY OF THE INVENTION 
   The present invention provides, in one aspect, a motorcycle including a front wheel, a rear wheel, a frame supported by the front and rear wheels, a crankcase including a first interface portion and a first passageway exposed to the first interface portion, a reservoir located remotely from the crankcase adapted to contain a lubricant, and a transmission case supported by the frame and including a second interface portion and a second passageway exposed to the second interface portion. The second passageway is in fluid communication with the reservoir. The first interface portion is coupled to the second interface portion. The first passageway is in fluid communication with the second passageway. The first and second passageways are adapted to provide fluid communication between the reservoir and the crankcase through the first and second interface portions. 
   Other features and aspects of the present invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings, wherein like reference numerals indicate like parts: 
       FIG. 1  is a front perspective view of a motorcycle embodying the present invention. 
       FIG. 2  is an exploded, perspective view of an engine and transmission case assembly of the motorcycle of  FIG. 1 , illustrating a gasket positioned between the engine and transmission case assembly. 
       FIG. 3  is an enlarged, front perspective view of the gasket of  FIG. 2 . 
       FIG. 4  is a top view of the gasket of  FIG. 2 . 
       FIG. 5  is an end view of the gasket of  FIG. 2 . 
       FIG. 6  is an assembled, perspective view of the engine and transmission case assembly of  FIG. 2 , illustrating a lubricant feed passageway through the engine and transmission case assembly. 
       FIG. 7  is an assembled, perspective view of the engine and transmission case assembly of  FIG. 2 , illustrating a lubricant return passageway through the engine and transmission case assembly. 
       FIG. 8  is an assembled, perspective view of the engine and transmission case assembly of  FIG. 2 , illustrating a vent passageway through the engine and transmission case assembly. 
       FIG. 9  is a cross-section view taken along line  9 - 9  of  FIG. 2 . 
       FIG. 10  is a side view of the engine and transmission case assembly of  FIG. 2 . 
     Before any features of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including”, “having”, and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The use of letters to identify elements of a method or process is simply for identification and is not meant to indicate that the elements should be performed in a particular order. 
   

   DETAILED DESCRIPTION 
     FIG. 1  illustrates a motorcycle  10  including a drive assembly  14 , a frame  18 , a front fork assembly  22 , a swing arm or rear fork assembly  26 , a front wheel  30 , a rear wheel  34 , a seat  38 , and a fuel tank  42 . The frame  18  supports the drive assembly  14 , the front fork assembly  22 , the rear fork assembly  26 , the seat  38 , and the fuel tank  42 . The front fork assembly  22  is pivotally supported at a front end of the motorcycle  10  and supports the front wheel  30 . The front fork assembly  22  includes a pair of handle bars  46  for steering the motorcycle  10 . The rear fork assembly  26  is coupled to the frame  18  at a rear end of the motorcycle  10  and rotatably supports the rear wheel  34 . The seat  38  is coupled to the frame  18  and is configured for supporting a rider. The fuel tank  42  is supported by the frame  18  and provides fuel to the drive assembly  14 . 
   The drive assembly  14  is coupled to the frame  18  beneath the seat  38  between the front wheel  30  and the rear wheel  34  of the motorcycle  10 . With continued reference to  FIG. 1 , the drive assembly  14  includes an engine  50  and a transmission  54 , which comprise distinct, independent components of the drive assembly  14 . The engine  50  comprises a V-twin engine  50  supported by the frame  18  forward of the transmission  54 . The engine  50  includes an output shaft (not shown), such as a crankshaft, which includes a primary drive sprocket (not shown) for driving a primary chain (not shown) in a conventional manner to power the transmission  54 . 
   The transmission  54  includes a transmission case assembly  58  including a transmission case  62  enclosing the internal components (not shown) of the transmission  54 . A gear chamber (not shown) in the transmission case  62  houses the internal components of the transmission  54 , particularly the transmission input and output shafts and various gears (not shown). Transmission lubricant is contained within the gear chamber to lubricate the working components of the transmission  54  (e.g., the input and output shafts and various gears). The transmission case assembly  58  also includes a pan  66  coupled to the transmission case  62 . The pan  66  defines a reservoir or a sump for containing engine lubricant, which is distributed throughout the engine  50  to lubricate the working components of the engine  50 . The engine lubricant is kept separately from the transmission lubricant, such that there is no cross-contamination between the engine lubricant and transmission lubricant. 
   The engine  50  includes a crankcase  70  and dual pumps (not shown) supported by the crankcase  70  and configured to transport lubricant throughout the engine  50  and transmission  54 . Specifically, a first pump is configured to scavenge lubricant from the sump and pump the lubricant to the engine  50  to lubricate the working components of the engine  50 . A second pump is configured to scavenge lubricant used by the engine  50  and pump the lubricant back to the sump. Both of the first pump and the second pump are mechanically driven by the crankshaft of the engine  50 . 
   With reference to  FIGS. 2 and 9 , the crankcase  70  and transmission case  62  are coupled along respective first and second interface portions  74 ,  78 . In the illustrated construction, the first and second interface portions  74 ,  78  are supported by respective flanges  82 ,  86  on the crankcase  70  and the transmission case  62 . Multiple fasteners may be used to couple the respective flanges  82 ,  86  of the crankcase  70  and the transmission case  62 . In the illustrated construction, bolts  90  are used to couple the flanges  82 ,  86 , but other fasteners may be used in alternate constructions. 
   With reference to  FIG. 10 , the first and second interface portions  74 ,  78  define a plane  94  when the first and second interface portions  74 ,  78  are coupled. The plane  94  is angularly oriented or canted relative to a vertical plane  98  passing through the second interface portions  78 . In the illustrated construction, the plane  94  is canted relative to the vertical plane  98  by an angle θ of about 3 degrees. Alternatively, the plane  94  may be canted relative to the vertical plane  98  more or less than about 3 degrees. 
   With reference to  FIG. 2 , the engine  50  and transmission case assembly  58  includes a plurality of internal passageways throughout the crankcase  70  and transmission case  62 . Specifically, with reference to the engine  50 , a lubricant feed passageway  102  in the crankcase  70  is in fluid communication with the inlet of the first pump, such that lubricant from the sump is drawn through the lubricant feed passageway  102  by operation of the first pump. The crankcase  70  also includes a lubricant return passageway  106  in fluid communication with the outlet of the second pump, such that lubricant used by the engine  50  is discharged by the second pump through the lubricant return passageway  106  toward the sump. The crankcase  70  further includes a vent passageway  110  in fluid communication with one or more of a crankshaft chamber (not shown) and a camshaft chamber (not shown) in the crankcase  70 . Each of the feed passageway  102 , return passageway  106 , and vent passageway  106  are exposed to the first interface portion  74  of the crankcase  70 . 
   With reference to the transmission  54 , a lubricant feed passageway  114  in the transmission case  62  is in fluid communication with the sump, such that lubricant from the sump is drawn through the lubricant feed passageway  114  by operation of the first pump. The transmission case  62  also includes a lubricant return passageway  118  in fluid communication with the sump, such that lubricant used by the engine  50  is returned to the sump by operation of the second pump. The transmission case  62  further includes a vent passageway  122  in fluid communication with the sump. Each of the feed passageway  114 , return passageway  118 , and vent passageway  122  are exposed to the second interface portion  78  of the transmission case  62 . 
   Upon coupling the crankcase  70  and transmission case  62  along the respective first and second interface portions  74 ,  78 , the respective feed passageways  102 ,  114 , return passageways  106 ,  118 , and vent passageways  110 ,  122  are in fluid communication with each other across the first and second interface portions  74 ,  78 . During operation of the motorcycle  10 , the first pump draws lubricant from the sump, through the respective feed passageways  114 ,  102  of the transmission case  62  and the crankcase  70 , pressurizes the lubricant, and discharges the pressurized lubricant to the working components of the engine  50  (see  FIG. 6 ). Likewise, the second pump draws “used” lubricant form the crankcase  70 , pressurizes the used lubricant, and discharges the pressurized lubricant toward the sump through the respective return passageways  106 ,  118  of the crankcase  70  and the transmission case  62  (see  FIG. 7 ). 
   Also, during operation of the motorcycle  10 , the respective vent passageways  110 ,  122  in the crankcase  70  and transmission case  62  fluidly communicate the crankshaft and/or camshaft chambers in the crankcase  70  and the sump (see  FIG. 8 ) to substantially equalize the vapor pressure in the engine  50  and the transmission  54 , allowing the level of lubricant in the sump to rise and fall. 
   With continued reference to  FIG. 8 , the respective vent passageways  110 ,  122  in the crankcase  70  and the transmission case  62  are aligned when the first and second interface portions  74 ,  78  are coupled. With reference to  FIGS. 6 and 7 , however, the respective feed passageways  102 ,  114  and the respective return passageways  106 ,  118  in the crankcase  70  and transmission case  62  are offset when the first and second interface portions  74 ,  78  are coupled. With reference to  FIGS. 2 and 9 , respective channels  126 ,  130  in the first and second interface portions  74 ,  78  fluidly communicate the offset feed passageways  102 ,  114  when the first and second interface portions  74 ,  78  are coupled. Likewise, respective channels  134 ,  138  in the first and second interface portions  74 ,  78  fluidly communicate the offset return passageways  106 ,  118  when the first and second interface portions  74 ,  78  are coupled. 
   In the illustrated construction, channels  126 ,  134  are formed in the first interface portion  74 , and channels  130 ,  138  are formed in the second interface portion  78 . In an alternate construction, the channels may be formed in only one of the first and second interface portions  74 ,  78  to fluidly communicate the offset passageways  102 ,  114  and  106 ,  118 . In another alternate construction, the respective feed passageways  102 ,  114  and the respective return passageways  106 ,  118  may be configured in the crankcase  70  and transmission case  62  to be aligned when the first and second interface portions  74 ,  78  are coupled. 
   With reference to  FIG. 2 , a gasket  142  is positioned between the engine  50  and transmission case assembly  58  to seal the respective feed passageways  102 ,  114 , return passageways  106 ,  118 , and vent passageways  110 ,  122 . The gasket  142  includes a base plate  146 , a plurality of apertures  150 ,  154 ,  158  through the base plate  146 , and a plurality of seals  162 ,  166 ,  170  coupled to the base plate  146  around the apertures  150 ,  154 ,  158  (see  FIGS. 3 and 4 ). Specifically, the aperture  150  allows fluid communication between the feed passageways  102 ,  114  when the first and second interface portions  74 ,  78  are coupled, the aperture  154  allows fluid communication between the return passageways  106 ,  118  when the first and second interface portions  74 ,  78  are coupled, and the aperture  158  allows fluid communication between the vent passageways  110 ,  122  when the first and second interface portions  74 ,  78  are coupled. 
   As shown in  FIGS. 2 and 3 , the aperture  150  is sized to accommodate the respective channels  126 ,  130  in the first and second interface portions  74 ,  78 , the aperture  154  is sized to accommodate the respective channels  134 ,  138  in the first and second interface portions  74 ,  78 , and the aperture  150  is sized to accommodate the respective vent passageways  110 ,  122  in the first and second interface portions  74 ,  78 . In the illustrated construction, the seals  162 ,  166 ,  170  are bonded to the base plate  146  around the periphery of the respective apertures  150 ,  154 ,  158 . The seals  162 ,  166 ,  170  are made from an elastomeric material (e.g., rubber) to allow compression of the seals  162 ,  166 ,  170  upon coupling the first and second interface portions  74 ,  78 . 
   With reference to  FIGS. 4-5 , the gasket  142  includes clips  174  for retaining the gasket  142  to at least one of the first interface portion  74  and second interface portion  78 . In the illustrated construction, the gasket  142  utilizes two clips  174 . However, alternate constructions of the gasket  142  may utilize more or less than two clips  174  to retain the gasket  142  to the second interface portion  78 . Also, in the illustrated construction, the clips  174  engage holes  178  in the second interface portion  78 . Alternate constructions of the gasket  142 , crankcase  70 , and transmission case  62  may include holes in the first interface portion  74  which the clips  174  may engage to retain the gasket  142  to the first interface portion  74 . As shown in  FIG. 5 , the clips  174  include a plurality of barbs  182  for resisting disengagement from the holes  178 . 
   With reference to  FIG. 9 , the base plate  146  of the gasket  142  is positioned within a recessed portion  186  of the second interface portion  78 . In an alternate construction, however, the recessed portion  186  may be incorporated in the first interface portion  74 , or both the first and second interface portions  74 ,  78 . The recessed portion  186  is sized such that, upon coupling the first and second interface portions  74 ,  78 , the seals  162 ,  166 ,  170  are compressed without clamping the base plate  146  between the first and second interface portions  74 ,  78 . The base plate  146  merely serves to orient the seals  162 ,  166 ,  170  with respect to the channels  126 ,  134  in the crankcase  70 , the channels  130 ,  138  in the transmission case  62 , and the vent passageways  110 ,  122 . By not clamping the base plate  146  between the respective flanges  82 ,  86  of the first and second interface portions  74 ,  78 , tolerance stacking between the flanges  82 ,  86  and the base plate  146  is reduced. 
   Various aspects of the inventionare set forth in the following claims