Differential Transmission With Cleaning Feature
AssigneeDeere & Company
InventorThomas Hung Vu
Life of this patent
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Abstract
A limited slip differential transmission of the closed type in which a pressurized lubricant is fed to the rotating gears and a series of limited slip clutch plates. The clutch plates are engaged by pressurized control fluid. A valve assembly having a spool valve is responsive to engagement pressure to permit discharge of a portion of pressurized fluid from the clutch plates to a sump chamber and the transmission to purge debris that may have accumulated in the clutch plates. The spool valve is arranged so that fluid is passed only during an intermediate movement of the valve to minimize any pressure loss from the lubricating fluid for the transmission and limited slip clutches.
Claims19
Apparatus for purging contaminants from lubricant pockets of a limited slip differential transmission having a sealed, pressurized system for rotating and inter-engaging parts of said transmission, said apparatus comprising:
- a valve element displaceable between a first and second position in response to a control feature of said transmission;
- passages formed in transmission between said lubricant pockets and a sump for said transmission, said valve element being interposed in said passages and configured to permit flow from said lubricant pocket to said sump as said valve element displaces between said first and second position.
A transmission differential comprising:
- a case journaled for rotation about a main axis;
- first and second rotatable output shafts received by the case and journaled about said main axis and having first and second bevel sun gears affixed thereto, respectively;
- a plurality of bevel planet gears, each rotatably mounted on said case in meshing engagement with said first and second bevel sun gears;
- a device selectively engagable between said case and one of said sun gears for limiting differential action;
- a system for supplying pressurized lubricant to journal said case, gears and said selectively engageable device, said transmission being arranged to seal said case, gears and selectively engageable device;
- said transmission having a sump chamber for receiving lubricant from said case and gears;
- said transmission having a passage from said selectively engageable device to said sump;
- and
- a valve element interposed in said passage and displaceable between a first and second position in response to engagement and disengagement of said selectively engageable device, said valve element being configured to permit flow of pressurized lubricant from said selectively engageable device and said sump as said valve element is displaceable between said first and second positions to purge contaminants from said selectively engageable device.
Dependencies are inferred from the claim text.