Rack and pinion steering gear unit

Patent metadata

Field	Value
Publication number	US-9656685-B2
Application number	US-201214348292-A
Country	US
Kind code	B2
Filing date	Aug 24, 2012
Priority date	Nov 15, 2011
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

Construction is achieved that is able to effectively prevent the displacement in the axial direction of a ball bearing 16 that supports the middle section of a pinion shaft 6 so as to be able to rotate freely, and that is compact and low cost. A fastening groove 28 b is formed around the entire circumference of a portion near an opening of the inner circumferential surface of a sub housing section 12 c of a casing 10 c , and a radially outside portion of a C-shaped retaining ring 29 b is fastened in this fastening groove 28 b . As a result, a side surface in the axial direction of a radially inside portion of the retaining ring 29 b is pressed against a side surface in the axial direction of an outer ring 18 of a ball bearing 16 that is fitted inside and supported by the inner circumferential surface of the sub housing section 12 c . Moreover, a clip 35 having a radially outside arm section 43 and radially inside arm section 44 is mounted in the opening edge section of the sub housing section 12 c , and a diameter reduction prevention section 36 that comprises the tip-end section of the radially inside arm section 44 is inserted into a non-continuous area 34 of the retaining ring 29 b.

First claim

What is claimed is:

1. A rack and pinion steering gear unit comprising:
a casing having a cylindrical shaped main housing section that is open on both ends, and a cylindrical shaped sub housing section that is open on one end and is provided in a twisted position with respect to the main housing section;
a rack shaft having rack teeth on a front surface thereof, and is located on an inside of the main housing section of the casing so as to be able to displace in an axial direction thereof;
a pinion shaft having pinion teeth that are formed on a tip half section in an axial direction thereof and that engage with the rack teeth, and with a base end section in an axial direction thereof protruding to an outside through an opening section of the sub housing section of the casing, is supported inside the sub housing section so at to be able to rotate freely;
a rolling bearing comprising an inner ring having an inner raceway around an outer circumferential surface thereof, an outer ring having an outer raceway around an inner circumferential surface thereof, and a plurality of rolling bodies that are provided between the inner raceway and outer raceway so as to be able to roll freely; and in order to support the pinion shaft inside the sub housing section, the inner ring is fastened around a portion of the pinion shaft that is closer to the base end section side in the axial direction than a portion where the pinion teeth are formed, and with one side surface in the axial direction of the outer ring being in contact with a stepped surface that is formed around the inner circumferential surface of the sub housing section, the outer ring is fitted inside and supported to the sub housing section;
a C-shaped incomplete circular ring shaped retaining ring that is located around a middle section in the axial direction of the pinion shaft, that is provided with a non-continuous area, and that, with a radially outside portion thereof fastened to a fastening groove that is formed around the inner circumferential surface near the opening section of the sub housing section, presses one side surface in the axial direction of a radially inside portion thereof against other side surface in the axial direction of the outer ring so as to apply a preload to the ball bearing; and
a diameter reduction prevention section that is provided on part of a member that is fastened to an opening side end section or a section near the opening section of the sub housing section, and by being inserted inside the non-continuous area of the retaining ring and engaging with the retaining ring, prevents reduction of the diameter of the retaining ring, wherein
the non-continuous area of the retaining ring is located on a rack shaft side of the retaining ring,
a clip that comprises a radially outside arm section and a radially inside arm section is elastically mounted to an opening side end section of the sub housing section so as to span the opening side end section, and the diameter reduction prevention section is constructed by a tip-end section of the radially inside arm section that is placed inside of the sub housing section, and
a stopper structure for preventing the clip from coming out from the opening side end section of the sub housing section is provided between the clip and the sub housing section on an outer circumferential surface side of the opening side end section of the sub housing section.

2. The rack and pinion steering gear unit according to claim 1 , wherein
the stopper structure comprises an inclined surface that is formed on the outer circumferential surface side that is inclined in a direction such that a thickness of the opening side end section becomes larger toward the opening section side, and an inclined section that is formed on the radially outside arm section of the clip, and that is inclined in a direction so as to become closer to the radially inside arm section toward a tip-end section side thereof, and comes in contact with the inclined surface.

3. The rack and pinion steering gear unit according to claim 1 , wherein
the stopper structure comprises an engagement concave groove that is formed around an outer circumferential surface of the opening side end section of the sub housing section, and a radially outside engagement protrusion that is formed on the radially outside arm section of the clip and engages with the engagement concave groove.

Assignees

• Iwakawa Masato
• Nsk Ltd

Inventors

• Iwakawa Masato

Classifications

• F16C2226/74

  with snap-fit, e.g. by clips · CPC title

• F16C19/54

  Systems consisting of a plurality of bearings with rolling friction (spindle bearings F16C35/08) · CPC title

• F16B21/183

  internal, i.e. with spreading action · CPC title

• F16C19/06

  with a single row or balls · CPC title

• F16C2326/24

  Steering systems, e.g. steering rods or columns · CPC title