Rotation-linear motion conversion apparatus and steering apparatus
A rotation-linear motion conversion apparatus ( 10 ) includes: a rack bar ( 30 ) in which a rack gear ( 32 ) is formed; a housing ( 40 ) that surrounds the rack bar ( 30 ); a pinion shaft ( 20 ) including a pinion gear ( 22 ) that engages with the rack gear ( 32 ) and that is inserted inside the housing ( 40 ); and a support part ( 50 ) that is provided on an opposed surface ( 41 s 1 ), which is opposed to the rack gear ( 32 ), of the housing ( 40 ) and that supports the rack bar ( 30 ) movably in a longitudinal direction of the rack bar ( 30 ).
1. A rotation-linear motion conversion apparatus, comprising:
a rack bar in which a rack gear is formed;
a housing that surrounds the rack bar;
a pinion shaft comprising a pinion gear that engages with the rack gear and that is inserted inside the housing; and
a support part that is provided on an opposed surface, which is opposed to the rack gear, of the housing and that supports the rack bar movably in a longitudinal direction of the rack bar, wherein
the support part is in non-contact with a non-opposed surface, which is not opposed to the rack gear, of the housing.
2. The rotation-linear motion conversion apparatus according to claim 1 , wherein
the support part comprises:
a holding part that holds a holding surface on which the rack gear of the rack bar is not formed; and
an attachment part that is provided on the opposed surface of the housing.
3. The rotation-linear motion conversion apparatus according to claim 2 , wherein
the support part comprises a plurality of the attachment parts, and
the pinion gear is arranged between the plurality of the attachment parts.
4. The rotation-linear motion conversion apparatus according to claim 3 , wherein
the holding part is formed integrally with the plurality of the attachment parts.
5. The rotation-linear motion conversion apparatus according to claim 1 , wherein
the rack bar comprises a rolling element rolling surface in the longitudinal direction,
the support part comprises: a loaded rolling element rolling surface opposed to the rolling element rolling surface and which forms a loaded rolling element rolling path; a rolling element return path that is provided in parallel with the loaded rolling element rolling path; and a direction change path that connects the loaded rolling element rolling path and the rolling element return path, and
the rotation-linear motion conversion apparatus comprises a plurality of rolling elements that circulate a boundless cyclic path formed of the loaded rolling element rolling path, the rolling element return path, and the direction change path.
6. The rotation-linear motion conversion apparatus according to claim 2 , wherein
the rack bar comprises a rolling element rolling surface in the longitudinal direction,
the support part comprises: a loaded rolling element rolling surface opposed to the rolling element rolling surface and which forms a loaded rolling element rolling path; a rolling element return path that is provided in parallel with the loaded rolling element rolling path; and a direction change path that connects the loaded rolling element rolling path and the rolling element return path, and
the rotation-linear motion conversion apparatus comprises a plurality of rolling elements that circulate a boundless cyclic path formed of the loaded rolling element rolling path, the rolling element return path, and the direction change path.
7. The rotation-linear motion conversion apparatus according to claim 3 , wherein
the rack bar comprises a rolling element rolling surface in the longitudinal direction,
the support part comprises: a loaded rolling element rolling surface opposed to the rolling element rolling surface and which forms a loaded rolling element rolling path; a rolling element return path that is provided in parallel with the loaded rolling element rolling path; and a direction change path that connects the loaded rolling element rolling path and the rolling element return path, and
the rotation-linear motion conversion apparatus comprises a plurality of rolling elements that circulate a boundless cyclic path formed of the loaded rolling element rolling path, the rolling element return path, and the direction change path.
8. The rotation-linear motion conversion apparatus according to claim 4 , wherein
the rack bar comprises a rolling element rolling surface in the longitudinal direction,
the support part comprises: a loaded rolling element rolling surface opposed to the rolling element rolling surface and which forms a loaded rolling element rolling path; a rolling element return path that is provided in parallel with the loaded rolling element rolling path; and a direction change path that connects the loaded rolling element rolling path and the rolling element return path, and
the rotation-linear motion conversion apparatus comprises a plurality of rolling elements that circulate a boundless cyclic path formed of the loaded rolling element rolling path, the rolling element return path, and the direction change path.
9. A steering apparatus, comprising:
a steering shaft that is connected to a steering wheel;
a link member that is connected to a wheel; and
a rotation-linear motion conversion apparatus that converts a rotation of the steering shaft into a linear motion and that linearly moves the link member, wherein
the steering apparatus comprises a rotation-linear motion conversion apparatus according to claim 1 as the rotation-linear motion conversion apparatus.
10. A steering apparatus, comprising:
a steering shaft that is connected to a steering wheel;
a link member that is connected to a wheel; and
a rotation-linear motion conversion apparatus that converts a rotation of the steering shaft into a linear motion and that linearly moves the link member, wherein
the steering apparatus comprises a rotation-linear motion conversion apparatus according to claim 2 as the rotation-linear motion conversion apparatus.
11. A steering apparatus, comprising:
a steering shaft that is connected to a steering wheel;
a link member that is connected to a wheel; and
a rotation-linear motion conversion apparatus that converts a rotation of the steering shaft into a linear motion and that linearly moves the link member, wherein
the steering apparatus comprises a rotation-linear motion conversion apparatus according to claim 3 as the rotation-linear motion conversion apparatus.
12. A steering apparatus, comprising:
a steering shaft that is connected to a steering wheel;
a link member that is connected to a wheel; and
a rotation-linear motion conversion apparatus that converts a rotation of the steering shaft into a linear motion and that linearly moves the link member, wherein
the steering apparatus comprises a rotation-linear motion conversion apparatus according to claim 4 as the rotation-linear motion conversion apparatus.
13. A steering apparatus, comprising:
a steering shaft that is connected to a steering wheel;
a link member that is connected to a wheel; and
a rotation-linear motion conversion apparatus that converts a rotation of the steering shaft into a linear motion and that linearly moves the link member, wherein
the steering apparatus comprises a rotation-linear motion conversion apparatus according to claim 5 as the rotation-linear motion conversion apparatus.
14. A steering apparatus, comprising:
a steering shaft that is connected to a steering wheel;
a link member that is connected to a wheel; and
a rotation-linear motion conversion apparatus that converts a rotation of the steering shaft into a linear motion and that linearly moves the link member, wherein
the steering apparatus comprises a rotation-linear motion conversion apparatus according to claim 6 as the rotation-linear motion conversion apparatus.
15. A steering apparatus, comprising:
a steering shaft that is connected to a steering wheel;
a link member that is connected to a wheel; and
a rotation-linear motion conversion apparatus that converts a rotation of the steering shaft into a linear motion and that linearly moves the link member, wherein
the steering apparatus comprises a rotation-linear motion conversion apparatus according to claim 8 as the rotation-linear motion conversion apparatus.
16. A steering apparatus, comprising:
a steering shaft that is connected to a steering wheel;
a link member that is connected to a wheel; and
a rotation-linear motion conversion apparatus that converts a rotation of the steering shaft into a linear motion and that linearly moves the link member, wherein
the steering apparatus comprises a rotation-linear motion conversion apparatus according to claim 9 as the rotation-linear motion conversion apparatus.