Fail-safe device for an electrical power assisted steering system including an in-line clutch mechanism
A power assisted steering system for a vehicle is described, the vehicle having an operator controlled steering mechanism, at least one steered wheel and a steering shaft directly connecting the steering mechanism to the wheel. The system consists of: a bidirectional electric motor; control means for energizing the motor to turn in a first direction when the steering mechanism is moved in one direction by the operator, for energizing the motor to turn in a direction opposite the first direction when the steering mechanism is moved in a direction opposite the one direction by the operator, for monitoring the operational condition of the system to detect malfunctions, and for generating a signal indicative of the operational condition system; a gear reduction means connected between the motor and the steering shaft for increasing the torque delivered to the steering shaft by the motor; clutch means, responsive to the control means for coupling the motor to the ratio reduction means when the system is operating properly and for isolating the motor from the ratio reduction means when the system is not operating properly, and the clutch means including a first clutch half and a coaxial second clutch half, the first clutch half being axially mounted on the motor armature for rotation therewith, second clutch half being axially mounted on the gear reduction means for rotation therewith, and further including means, responsive to the control means for moving one of the first or second clutch halves into frictional contact with the other of the first or second halves when the system is operating properly.
- Assignee:
- Eaton Corp., Cleveland, OH
- Patent Number(s):
- US 4573545
- OSTI ID:
- 5686773
- Country of Publication:
- United States
- Language:
- English
Similar Records
Power transfer device for four-wheel drive
Transmission for self-propelled working vehicles