Transmission system

Abstract

A transmission system includes a housing having a sump, the housing containing a crown wheel and a pinion. The transmission system further includes an oil reservoir and a pump selectively operable to pump fluid from the oil reservoir to the sump for lubricating the crown wheel. The pump is selectively operable to pump fluid from the sump to the reservoir.

1 . A transmission system comprising:
 a housing including a sump, wherein the housing contains a crown wheel and a pinion, wherein a part of the crown wheel is received in a part of the sump;   a reservoir; and   a pump system selectively operable to pump fluid from the reservoir to the sump to increase an oil level in the sump, wherein the pump system is selectively operable to pump the fluid from the sump to the reservoir to decrease the oil level in the sump.   
     
     
         2 . The transmission system as defined in  claim 1  wherein the pump system includes a pump which is driven in a first direction to selectively pump the fluid from the reservoir to the sump, and the pump is driven in a second direction to selectively pump the fluid from the sump to the reservoir. 
     
     
         3 . The transmission system as defined in  claim 1  wherein the pump system includes a pump and a first flow diverter valve upstream from the pump selectively operable to connect the pump to one of the reservoir and the sump and a second flow diverter valve downstream from the pump selectively operable to connect the pump to the other of the reservoir and the sump. 
     
     
         4 . The transmission system as defined in  claim 1  wherein the pump system includes a first pump selectively operable to pump the fluid from the reservoir to the sump and a second pump selectively operable to pump the fluid from the sump to the reservoir. 
     
     
         5 . The transmission system as defined in  claim 1  wherein the housing contains the reservoir. 
     
     
         6 . The transmission system as defined in  claim 5  wherein the reservoir is substantially C-shaped and faces teeth of the crown wheel. 
     
     
         7 . The transmission system as defined in  claim 5  wherein a lower portion of the reservoir is positioned in the sump. 
     
     
         8 . The transmission system as defined in  claim 1  wherein the housing is defined by an axle housing having an opening sized to receive the crown wheel and a carrier upon which the crown wheel and the pinion are mounted, wherein the carrier has a flange sized to substantially close the opening, and the reservoir is mounted on the carrier. 
     
     
         9 . The transmission system as defined in  claim 8  wherein the pump system is mounted on the carrier, on the reservoir, or in the reservoir. 
     
     
         10 . The transmission system as defined in  claim 8  wherein at least one of a first valve and a second valve is mounted on the carrier, on the reservoir, or in the reservoir. 
     
     
         11 . The transmission system as defined in  claim 1  wherein the reservoir is mounted externally relative to the housing. 
     
     
         12 . The transmission system as defined in  claim 11  wherein the housing is defined by an axle housing having an opening sized to receive the crown wheel and a carrier upon which the crown wheel and the pinion are mounted, wherein the carrier has a flange sized to substantially close the opening, the axle housing includes an axle arm for receiving a drive shaft, and the reservoir is mounted on an axle arm. 
     
     
         13 . The transmission system as defined in  claim 12  wherein the reservoir partially surrounds the axle arm. 
     
     
         14 . The transmission system as defined in  claim 1  wherein an inlet for the pump system is positioned in the sump at a level higher than a bottom of the crown wheel.