Transmission case vent

Abstract

The present invention provides a transmission case assembly adapted for use with a motorcycle. The transmission case assembly includes a transmission case having a gear chamber adapted to contain a lubricant and generate a lubricant-laden mist during operation of the motorcycle, and a breather chamber in fluid communication with the gear chamber. The breather chamber is adapted to separate the lubricant-laden mist into lubricant and vapor and drain the separated lubricant into the gear chamber. The transmission case assembly also includes a transmission case cover coupled to the transmission case. The transmission case cover includes at least a portion of a passageway in fluid communication between the breather chamber and ambient air outside of the transmission case assembly. The passageway is adapted to exhaust the separated vapor outside of the transmission case assembly.

1 . A transmission case assembly adapted for use with a motorcycle, the transmission case assembly comprising: 
 a transmission case including 
 a gear chamber adapted to contain a lubricant and generate a lubricant-laden mist during operation of the motorcycle, and  
 a breather chamber in fluid communication with the gear chamber, the breather chamber adapted to separate the lubricant-laden mist into lubricant and vapor and drain the separated lubricant into the gear chamber; and  
   a transmission case cover coupled to the transmission case, the transmission case cover including at least a portion of a passageway in fluid communication between the breather chamber and ambient air outside of the transmission case assembly, the passageway adapted to exhaust the separated vapor outside of the transmission case assembly.    
   
   
       2 . The transmission case assembly of  claim 1 , further comprising: 
 a vapor chamber in the transmission case cover, wherein the passageway is in fluid communication between the vapor chamber and ambient air outside of the transmission case assembly; and    a baffle positioned between the breather chamber and the vapor chamber, wherein the baffle at least partially restricts fluid flow between the breather chamber and the vapor chamber, and wherein the baffle is adapted to facilitate separation of the lubricant-laden mist into lubricant and vapor.    
   
   
       3 . The transmission case assembly of  claim 2 , wherein the baffle comprises a gasket including at least one aperture to fluidly communicate the breather chamber and the vapor chamber.  
   
   
       4 . The transmission case assembly of  claim 3 , wherein the at least one aperture is positioned on a side of the gasket opposite the portion of the passageway in the transmission case cover.  
   
   
       5 . The transmission case assembly of  claim 1 , wherein the transmission case includes a first interface portion, wherein the transmission case cover includes a second interface portion coupled to the first interface portion, and wherein the passageway passes through the first interface portion and the second interface portion.  
   
   
       6 . The transmission case assembly of  claim 5 , further comprising an ear extending from the first interface portion, wherein the ear at least partially defines a groove in the transmission case, and wherein the groove comprises a portion of the passageway.  
   
   
       7 . The transmission case assembly of  claim 1 , wherein the transmission case cover includes a groove comprising the portion of the passageway.  
   
   
       8 . The transmission case assembly of  claim 1 , wherein the passageway is integrally formed with the transmission case cover and the transmission case.  
   
   
       9 . A transmission case assembly adapted for use with a motorcycle, the transmission case assembly comprising: 
 a transmission case including 
 a first interface portion,  
 a gear chamber adapted to contain a lubricant and generate a lubricant-laden mist during operation of the motorcycle, and  
 a breather chamber in fluid communication with the gear chamber to receive the lubricant-laden mist, the breather chamber adapted to at least partially facilitate separation of the lubricant-laden mist into lubricant and vapor;  
   a transmission case cover including a second interface portion coupled to the first interface portion, the transmission case cover including a vapor chamber in fluid communication with the breather chamber and adapted to receive the separated vapor; and    a tortuous passageway fluidly communicating the gear chamber and ambient air outside of the transmission case assembly, at least a portion of the tortuous passageway passing through the first and second interface portions.    
   
   
       10 . The transmission case assembly of  claim 9 , further comprising a baffle positioned between the breather chamber and the vapor chamber, the baffle at least partially restricting fluid flow between the breather chamber and the vapor chamber, the baffle adapted to facilitate separation of the lubricant-laden mist into lubricant and vapor, the breather chamber adapted to accumulate the separated lubricant and drain the separated lubricant into the gear chamber, wherein at least a portion of the tortuous passageway passes through the baffle.  
   
   
       11 . The transmission case assembly of  claim 10 , wherein the baffle comprises a gasket including at least one aperture to fluidly communicate the breather chamber and the vapor chamber.  
   
   
       12 . The transmission case assembly of  claim 11 , wherein the at least one aperture is positioned on a side of the gasket opposite the portion of the tortuous passageway passing through the first and second interface portions.  
   
   
       13 . The transmission case assembly of  claim 9 , further comprising an ear extending from the first interface portion, wherein the ear at least partially defines a groove in the transmission case, and wherein the groove comprises a portion of the tortuous passageway.  
   
   
       14 . The transmission case assembly of  claim 9 , wherein the second interface portion includes a groove, and wherein the groove comprises a portion of the tortuous passageway.  
   
   
       15 . The transmission case assembly of  claim 9 , wherein at least a portion of the tortuous passageway is integrally formed with the transmission case cover and the transmission case.  
   
   
       16 . A motorcycle comprising: 
 a front wheel;    a rear wheel;    a frame supported by the front and rear wheels;    a transmission case including 
 a gear chamber adapted to contain a lubricant and generate a lubricant-laden mist during operation of the motorcycle, and  
 a breather chamber in fluid communication with the gear chamber, the breather chamber adapted to separate the lubricant-laden mist into lubricant and vapor and drain the separated lubricant into the gear chamber; and  
   a transmission case cover coupled to the transmission case, the transmission case cover including at least a portion of a passageway in fluid communication between the breather chamber and ambient air outside of the transmission case assembly, the passageway adapted to exhaust the separated vapor outside of the transmission case assembly.    
   
   
       17 . The transmission case assembly of  claim 16 , further comprising: 
 a vapor chamber in the transmission case cover, wherein the passageway is in fluid communication between the vapor chamber and ambient air outside of the transmission case assembly; and    a baffle positioned between the breather chamber and the vapor chamber, wherein the baffle at least partially restricts fluid flow between the breather chamber and the vapor chamber, and wherein the baffle is adapted to facilitate separation of the lubricant-laden mist into lubricant and vapor.    
   
   
       18 . The motorcycle of  claim 17 , wherein the baffle comprises a gasket including at least one aperture to fluidly communicate the breather chamber and the vapor chamber.  
   
   
       19 . The motorcycle of  claim 18 , wherein the at least one aperture is positioned on a side of the gasket opposite the portion of the passageway in the transmission case cover.  
   
   
       20 . The motorcycle of  claim 16 , wherein the transmission case includes a first interface portion, wherein the transmission case cover includes a second interface portion engaged with the first interface portion, and wherein the passageway passes through the first interface portion and the second interface portion.  
   
   
       21 . The motorcycle of  claim 20 , further comprising an ear extending from the first interface portion, wherein the ear at least partially defines a groove in the transmission case, and wherein the groove comprises a portion of the passageway.  
   
   
       22 . The motorcycle of  claim 16 , wherein the transmission case cover includes a groove comprising the portion of the passageway.  
   
   
       23 . The motorcycle of  claim 16 , wherein the passageway is integrally formed with the transmission case cover and the transmission case.  
   
   
       24 . A motorcycle comprising: 
 a front wheel;    a rear wheel;    a frame supported by the front and rear wheels;    a transmission case including 
 a first interface portion,  
 a gear chamber adapted to contain a lubricant and generate a lubricant-laden mist during operation of the motorcycle, and  
 a breather chamber in fluid communication with the gear chamber to receive the lubricant-laden mist, the breather chamber adapted to at least partially facilitate separation of the lubricant-laden mist into lubricant and vapor;  
   a transmission case cover including a second interface portion coupled to the first interface portion, the transmission case cover including a vapor chamber in fluid communication with the breather chamber and adapted to receive the separated vapor; and    a tortuous passageway fluidly communicating the gear chamber and ambient air outside of the transmission case, at least a portion of the tortuous passageway passing through the first and second interface portions.    
   
   
       25 . The motorcycle of  claim 24 , further comprising a baffle positioned between the breather chamber and the vapor chamber, the baffle at least partially restricting fluid flow between the breather chamber and the vapor chamber, the baffle adapted to facilitate separation of the lubricant-laden mist into lubricant and vapor, the breather chamber adapted to accumulate the separated lubricant and drain the separated lubricant into the gear chamber, wherein at least a portion of the tortuous passageway passes through the baffle.  
   
   
       26 . The motorcycle of  claim 25 , wherein the baffle comprises a gasket including at least one aperture to fluidly communicate the breather chamber and the vapor chamber.  
   
   
       27 . The motorcycle of  claim 26 , wherein the at least one aperture is positioned on a side of the gasket opposite the portion of the tortuous passageway passing through the first and second interface portions.  
   
   
       28 . The motorcycle of  claim 24 , further comprising an ear extending from the first interface portion, wherein the ear at least partially defines a groove in the transmission case, and wherein the groove comprises a portion of the tortuous passageway.  
   
   
       29 . The motorcycle of  claim 24 , wherein the second interface portion includes a groove, and wherein the groove comprises a portion of the tortuous passageway.  
   
   
       30 . The motorcycle of  claim 24 , wherein at least a portion of the tortuous passageway is integrally formed with the transmission case cover and the transmission case.  
   
   
       31 . A transmission case cover adapted for use with a transmission case of a motorcycle, the transmission case including a first interface portion and a breather chamber that receives a lubricant-laden mist during operation of the motorcycle, the breather chamber adapted to at least partially facilitate separation of the lubricant-laden mist into lubricant and vapor, the transmission case cover comprising: 
 a second interface portion adapted to couple to the first interface portion of the transmission case;    a vapor chamber adapted to fluidly communicate with the breather chamber and adapted to receive the separated vapor; and    a groove formed in the second interface portion to fluidly communicate the vapor chamber and ambient air outside of the transmission case, the groove adapted to exhaust the separated vapor outside of the transmission case.    
   
   
       32 . The transmission case cover of  claim 31 , wherein the groove is integrally formed with the transmission case cover.