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US 10,309,502 B2Granted
Power steering device
AssigneeHitachi Automotive Systems, Ltd.
InventorsKeisuke Kitamura, Osamu Yoshida
Life of this patent
Estimating the term…
Abstract
A first member (81) including a first opening portion that opens to one side in a circumferential direction around an axis of a rack shaft corresponding to a rotation axis of a nut, and a second member (82) including a second opening portion that confronts the first opening portion, and that opens to the other side in the circumferential direction, are molded so that a first insertion portion (71) and a second insertion portion (72) are inclined along a lead angle of a ball circulation groove with respect to a connection portion (73), and the first and second openings are joined in an abutted state, thereby forming a tube (44).
Claims20
A power steering device comprising:
- a steered shaft arranged to be moved in an axial direction in accordance with a rotation of a steering wheel, and thereby to steer a steered wheel;
- a nut formed into a cylindrical shape surrounding the steered shaft, and arranged to be rotated relative to the steered shaft;
- a ball circulation groove including a shaft side ball screw groove having a helical groove shape, and provided on an outer circumference of the steered shaft, and a nut side ball screw groove having a helical groove shape, and provided on an inner circumference of the nut;
- a plurality of balls disposed within the ball circulation groove to be rolled within the ball circulation groove;
- a first connection passage including one end side opened on an outer circumference surface of the nut, and the other end side opened on an inner circumference surface of the nut, and opened on the one end side of the ball circulation groove;
- a second connection passage including one end side opened on the outer circumference surface of the nut, and the other end side opened on the inner circumference surface of the nut, and opened on the other end side of the ball circulation groove;
- a connection member connecting the first connection passage and the second connection passage to circulate the balls between the first connection passage and the second connection passage;
- and
- an electric motor arranged to drive and rotate the nut, and thereby to provide a steering force to the steered shaft;
- the connection member being constituted by joining a first member which is formed by a die forming, and which includes a first opening portion opened on one side in a circumferential direction around a rotation axis of the nut, and a second member which is formed by the die forming, and which includes a second opening portion that confronts the first opening, and that is opened on the other side in the circumferential direction,
- the connection member in the joint state including a first insertion portion inserted into the first connection passage, a second insertion portion inserted into the second connection passage, and a connection portion connecting the first insertion portion and the second insertion portion, and
- the first insertion portion and the second insertion portion being inclined along a lead angle of the ball circulation groove with respect to the connection portion.
9 more elements
A manufacturing method of a power steering device including a steered shaft arranged to be moved in an axial direction in accordance with a rotation of a steering wheel, and thereby to steer a steered wheel,
- a nut formed into a cylindrical shape surrounding the steered shaft, and arranged to be rotated relative to the steered shaft,
- a ball circulation groove including a shaft side ball screw groove having a helical groove shape, and provided on an outer circumference of the steered shaft, and a nut side ball screw groove having a helical groove shape, and provided on an inner circumference of the nut,
- a plurality of balls disposed within the ball circulation groove to be rolled within the ball circulation groove,
- a first connection passage including one end side opened on an outer circumference surface of the nut, and the other end side opened on an inner circumference surface of the nut, and opened on the one end side of the ball circulation groove,
- a second connection passage including one end side opened on the outer circumference surface of the nut, and the other end side opened on the inner circumference surface of the nut, and opened on the other end side of the ball circulation groove,
- a connection member including a first insertion portion inserted into the first connection passage, a second insertion portion inserted into the second connection passage, and a connection portion connecting the first insertion portion and the second connection portion, and connecting the first connection passage and the second connection passage to circulate the balls between the first connection passage and the second connection passage, and
- an electric motor arranged to drive and rotate the nut, and thereby to provide a steering force to the steered shaft, the manufacturing method comprising:
- die-forming a first member including a first opening portion opened on one side in a circumferential direction around a rotation axis of the nut, and a second member including a second opening portion that confronts the first opening, and that is opened on the other side in the circumferential direction so that the first insertion portion and the second insertion portion are inclined along a lead angle of the ball circulation groove with respect to the connection portion;
- and
- joining the first member and the second member to form the connection member.
7 more elements
Dependencies are inferred from the claim text.