Clutch lube control
AssigneeDeere & Company
InventorPeter D. Wetrich
Life of this patent
Estimating the term…
Abstract
A hydraulic control circuit controls flow of cooling oil to a wet clutch. The circuit normally maintains a reduced or zero flow, but temporarily increases flow of cooling oil when the clutch changes from a disengaged to an engaged state.
Claims6
In a vehicle having a torque-transmitting clutch with a clutch lube circuit and having engaged and disengaged states, an operator control for controlling the engagement state of the clutch and a source of lube fluid, a system for controlling flow of lube fluid to the lube circuit, comprising:
- a lube valve having an inlet for receiving lube fluid, an outlet coupled to the lube circuit and a spool movable between a first position wherein lube flow between the inlet and outlet is reduced and a second position wherein lube flow is increased;
- and
- control means coupled between the operator control and the lube valve and responsive to the operator control for normally maintaining the lube valve in its first reduced flow position and for temporarily maintaining the lube valve in its second increased flow position for a certain time period following a predetermined change in the engagement state of the clutch.
In a vehicle having a traction clutch, a power-take-off (PTO) clutch, a lube circuit for cooling both clutches, a traction operator control for controlling engagement states of the traction clutch, a PTO operator control for controlling engagement states of the PTO clutch and source of lube fluid, a system for controlling flow of lube fluid through the lube circuit;
- comprising:
- a first lube valve having an inlet communicated with the lube source, a first outlet communicated with the lube circuit, a second outlet and a spool having a first position blocking the first outlet and communicating the inlet with the first outlet and having a second position blocking the second outlet and communicating the inlet with the first outlet;
- a second lube valve having an inlet port communicating with the second outlet, an outlet port communicating with the lube circuit and a spool having a first position blocking the inlet and outlet ports and a second position communicating the inlet port with the outlet port;
- first control means coupled to the first lube valve and responsive to the traction operator control for normally maintaining the first lube valve spool in its first position and for temporarily placing the first lube valve spool in its second position in response to a change of the traction clutch from a disengaged to an engaged state;
- and
- second control means coupled to the second lube valve and responsive to the PTO operator control for normally maintaining the second lube valve spool in its first position and for temporarily placing the second lube valve spool in its second position in response to change of the PTO clutch from a disengaged to an engaged state.
Dependencies are inferred from the claim text.