US 6,578,685 B2 · Active control of a hydra-mechanical traction control device

Abstract

The hydraulic coupling includes a multi-plate clutch assembly operatively connecting a pair of rotary members, an actuator assembly for actuating the clutch assembly, and a fluid control system operable for controlling actuation of the actuator assembly including a hydraulic pump and a piston mounted in a piston chamber for movement relative to the multi-plate clutch assembly. The fluid control system regulates the fluid pressure supplied to the piston chamber by the hydraulic pump to control the clutch engagement force exerted by the piston on the clutch assembly. The fluid control system includes an electrically-controlled flow control valve operable for regulating the fluid pressure delivered to the piston chamber. Preferably, the flow control valve is a pulse-width modulated PWM) valve having a moveable valve element. The position of the valve element is controlled by an electronic traction control module that monitors and responds to certain vehicle operating conditions, including a sump fluid temperature, a coupling outlet oil temperature, four wheel speeds, and the piston chamber pressure. The electronic traction control module sends a control signal to the PWM control valve for modulating the hydraulic pressure supplied to the piston chamber, which, in turn, controls clutch engagement.

Claims29

Dependent claims

A hydraulic coupling for use in a motor vehicle driveline, comprising:

first and second rotary members;
a transfer clutch operatively connected between said first and second rotary members;
a piston disposed in a piston chamber and actuable to engage said transfer clutch;
a pump cover assembly fixed to said second rotary member;
a hydraulic pump in fluid communication with a sump containing hydraulic fluid, said hydraulic pump being retained in said pump cover assembly and having a first pump member fixed for rotation with said cover assembly and a second pump member fixed for rotation with said second rotary member such that relative rotation between said first and second pump members generates said pumping action;
a flow path for supplying said hydraulic fluid from said hydraulic pump to said piston chamber;
a control valve located in fluid communication with said flow path for regulating the pressure of said hydraulic fluid supplied to said piston chamber;
a sensor for detecting a physical property of said hydraulic fluid;
and
a traction control module for controlling actuation of said control valve in response to sensor signals from said sensor.

7 more elements

A hydraulic coupling for use in a motor vehicle to rotatively couple first and second rotary members, the hydraulic coupling comprising:

a transfer clutch connected between the first and second rotary members;
a piston disposed in a piston chamber and actuable to engage said transfer clutch for rotatively coupling the first and second rotary members;
a pump cover assembly that is fixed to the second rotary member;
a hydraulic pump in fluid communication with a sump containing hydraulic fluid, said hydraulic pump being retained in said pump cover assembly and having a first pump member fixed for rotation with said cover assembly and a second pump member fixed for rotation with the second rotary member such that relative rotation between said first and second pump members generates said pumping action;
a flow path for supplying hydraulic fluid from said hydraulic pump to said piston chamber;
a control valve located in fluid communication with said flow path for regulating the fluid pressure supplied to said piston chamber;
a first sensor for detecting the rotary speed of the first rotary member and generating a first speed signal;
a second sensor for detecting the rotary speed of the second rotary member and generating a second speed signal;
and
a control module for controlling actuation of said control valve in response said first and second speed signals.

7 more elements

A hydraulic coupling for use in a motor vehicle to rotatively couple first and second rotary members, the hydraulic coupling comprising:

a transfer clutch connected between the first and second rotary members and actuable by movement of a piston in a piston chamber;
a pump cover assembly connectable to the second rotary member;
a hydraulic pump in fluid communication with a sump containing hydraulic fluid, said hydraulic pump being retained in said pump cover assembly and having a first pump member fixed for rotation with said cover assembly and a second pump member connectable for rotation with the second rotary member such that relative rotation between said first and second pump members generates said pumping action;
a flow path for supplying hydraulic fluid from said hydraulic pump to said piston chamber;
a control valve in fluid communication with said flow path for regulating flow of hydraulic fluid into said piston chamber for controlling movement said piston;
and
a traction control system for controlling actuation of said control valve in response to signals from sensors which detect at least two different operating conditions of said hydraulic coupling.

4 more elements

Dependencies are inferred from the claim text.

Active control of a hydra-mechanical traction control device

Life of this patent

Active control of a hydra-mechanical traction control device

Life of this patent

Abstract

Claims29