Power steering device and backlash adjuster
AssigneeHitachi Automotive Systems Steering, Ltd.
InventorSusumu KIMOTO
Life of this patent
Estimating the term…
Abstract
In a power steering device employing both a worm speed reducer and a backlash adjuster for a worm gear of the speed reducer, the backlash adjuster has a slider configured to be movable in a longitudinal direction of a worm shaft, and a biasing member configured to bias the slider toward one side of the longitudinal direction of the worm shaft. Also provided is a guide member configured to bias the worm shaft in a direction for meshing with a worm wheel by a movement of the worm shaft in the meshing direction that the worm shaft approaches a rotation center of the worm wheel with a movement of the slider toward the one side of the longitudinal direction, and also configured to restrict a movement of the worm shaft in a direction opposite to the meshing direction of the worm shaft.
Claims20
A power steering device comprising:
- a steering mechanism having a steering shaft connected to a steering wheel and adapted to transmit a movement of the steering wheel to steered road wheels;
- an electric motor configured to apply a steering assist force to the steering mechanism;
- a speed reducer installed between the steering mechanism and the electric motor, and comprising a worm gear, the worm gear being constructed by a worm shaft whose one axial end is connected to the electric motor and a worm wheel in mesh with the worm shaft for transmitting torque of the electric motor to the steering shaft;
- a gear housing having a worm-wheel housing section in which the worm wheel is housed and a worm-shaft housing section in which the worm shaft is housed;
- a slider arranged at the other axial end of the worm shaft housed in the worm-shaft housing section of the gear housing and configured to be movable in a longitudinal direction of the worm shaft;
- a biasing member configured to bias the slider toward one side of the longitudinal direction of the worm shaft;
- and
- a guide member configured to bias the worm shaft in a direction for meshing with the worm wheel by a movement of the worm shaft in the meshing direction that the worm shaft approaches a rotation center of the worm wheel with a movement of the slider toward the one side of the longitudinal direction, and also configured to restrict a movement of the worm shaft in a direction opposite to the meshing direction of the worm shaft.
The power steering device as recited in claim further comprising:
- a sliding mechanism arranged radially outside of the rolling bearing for permitting a movement of the rolling bearing in the meshing direction, and for restricting a movement of the rolling bearing in a direction of a rotation axis of the worm wheel.
A backlash adjuster for adjusting backlash of a worm gear configured to transmit torque of an electric motor to a steering mechanism adapted to transmit a movement of a steering wheel to steered road wheels, the worm gear being constructed by a worm shaft and a worm wheel, the backlash adjuster comprising:
- a slider installed on a gear housing of the worm gear and configured to be movable in a longitudinal direction of the worm shaft;
- a biasing member configured to bias the slider toward one side of the longitudinal direction of the worm shaft;
- and
- a guide member configured to bias the worm shaft in a direction for meshing with the worm wheel by a movement of the worm shaft in the meshing direction that the worm shaft approaches a rotation center of the worm wheel with a movement of the slider toward the one side of the longitudinal direction, and also configured to restrict a movement of the worm shaft in a direction opposite to the meshing direction of the worm shaft.
Dependencies are inferred from the claim text.