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US 12,654,761 B2Granted
Electric power steering apparatus
AssigneeHl Mando Corporation
InventorWoong Soo Shin
Life of this patent
Estimating the term…
Abstract
An electric power steering apparatus includes: a pinion shaft connected to a steering shaft coupled to a steering wheel, the pinion shaft being configured to transmit an operation of the steering wheel by a driver; a rack bar elongated along a lateral direction of a vehicle, having a first screw recess defined with a predetermined length in a portion of an outer circumferential surface of the rack bar, and including, on one side, a rack gear coupled to and interlocked with the pinion shaft; a motor configured to generate a steering assist power in proportion to a steering torque applied to the steering wheel; and a roller screw unit rotatably engaged with and coupled to the first screw recess to transmit the steering assist power generated from the motor to the rack bar.
Claims9
An electric power steering apparatus comprising:
- a pinion shaft connected to a steering shaft coupled to a steering wheel, the pinion shaft being configured to transmit an operation of the steering wheel by a driver;
- a rack bar elongated along a lateral direction of a vehicle, having a first screw recess defined with a predetermined length in a portion of an outer circumferential surface of the rack bar, and comprising, on one side, a rack gear coupled to and interlocked with the pinion shaft;
- a motor configured to generate a steering assist power in proportion to a steering torque applied to the steering wheel;
- and
- a roller screw unit rotatably engaged with and coupled to the first screw recess to transmit the steering assist power generated from the motor to the rack bar,
- wherein the roller screw unit comprises:
- a plurality of screw members rotatably engaged with the first screw recess and are spaced apart from each other by a predetermined angle along a circumferential direction of the rack bar;
- a positioning member having a hollow defined along a longitudinal direction such that the rack bar is insertable through the positioning member, the positioning member being configured to fix a position of the screw members such that the screw members are rotatable only at a predetermined position;
- and
- a housing having a hollow defined along a longitudinal direction such that the positioning member and the rack bar are insertable through the housing, the housing being configured to protect the plurality of screw members and the positioning member and prevent the plurality of screw members from being separated from the positioning member,
- wherein in a body of the positioning member, a positioning hole is defined through inner and outer surfaces of the body, and
- the positioning hole comprises a plurality of positioning holes spaced apart from each other by a predetermined angle along a circumferential direction of the body,
- wherein when the rack bar and the positioning member are coupled to each other, the first screw recess is exposed, and
- the screw members are respectively disposed at the positioning holes such that the first screw recess and the screw members are engaged.
11 more elements
An electric power steering apparatus comprising:
- a pinion shaft connected to a steering shaft coupled to a steering wheel, the pinion shaft being configured to transmit an operation of the steering wheel by a driver;
- a rack bar elongated along a lateral direction of a vehicle, having a first screw recess defined with a predetermined length in a portion of an outer circumferential surface of the rack bar, and comprising, on one side, a rack gear coupled to and interlocked with the pinion shaft;
- a motor configured to generate a steering assist power in proportion to a steering torque applied to the steering wheel;
- and
- a roller screw unit rotatably engaged with and coupled to the first screw recess to transmit the steering assist power generated from the motor to the rack bar,
- wherein the roller screw unit comprises:
- a plurality of screw members rotatably engaged with the first screw recess, and spaced apart from each other by a predetermined angle along a circumferential direction of the rack bar;
- and
- a casing having a hollow defined along a longitudinal direction such that the rack bar and the plurality of the screw members are insertable through the casing, the casing being configured to prevent the plurality of the screw members from being separated from the rack bar, while protecting the rack bar and the plurality of screw members,
- wherein the screw members comprises:
- a plurality of main screws rotatably engaged with the first screw recess and spaced apart from each other by a predetermined interval in a longitudinal direction of the rack bar;
- a connection screw having one side connected to one of the main screws, and another side connected to another of the main screws;
- and
- a support shaft formed at a free end of the main screw disposed on the one side and a free end of the main screw located on the other side.
11 more elements
Dependencies are inferred from the claim text.