Gear and steering system

Patent metadata

Field	Value
Publication number	US-2024400128-A1
Application number	US-202118707759-A
Country	US
Kind code	A1
Filing date	Nov 26, 2021
Priority date	Nov 26, 2021
Publication date	Dec 5, 2024
Grant date	—

Abstract

A gear includes a resin sleeve having a disc shape, and a resin toothing that covers an outer peripheral portion of the sleeve and includes a plurality of gear teeth arranged at equal intervals in a circumferential direction. The sleeve includes a plurality of protrusions arranged on an outer peripheral surface at equal intervals in the circumferential direction, and a plurality of ribs arranged at equal intervals in the circumferential direction at positions on a radially inner side of the protrusions. A first installation location count L of the protrusions in the circumferential direction and a second installation location count M of the ribs in the circumferential direction are equal to each other and are integral multiples of a third installation location count N of the gear teeth in the circumferential direction.

First claim

1 . A gear comprising:
a resin sleeve having a disc shape; and a resin toothing that covers an outer peripheral portion of the sleeve and includes a plurality of gear teeth arranged at equal intervals in a circumferential direction, wherein: the sleeve includes
a plurality of protrusions arranged on an outer peripheral surface at equal intervals in the circumferential direction, and
a plurality of ribs arranged at equal intervals in the circumferential direction at positions on a radially inner side of the protrusions; and
a first installation location count of the protrusions in the circumferential direction and a second installation location count of the ribs in the circumferential direction are equal to each other and are integral multiples of a third installation location count of the gear teeth in the circumferential direction.

2 . The gear according to claim 1 , wherein the first installation location count and the second installation location count are equal to the third installation location count.

3 . The gear according to claim 1 , wherein a central line in the circumferential direction on a recess present between the plurality of protrusions in the circumferential direction is within a width of the rib in the circumferential direction.

4 . The gear according to claim 3 , wherein the central line of the recess in the circumferential direction coincides with a central line of the rib in the circumferential direction.

5 . The gear according to claim 1 , wherein:
the plurality of ribs includes a plurality of first ribs provided on one principal surface of the sleeve, and a plurality of second ribs provided on the other principal surface of the sleeve; and a central line of the gear tooth in an axial direction is present at a position in the axial direction between a first hole that is present between the plurality of first ribs in the circumferential direction and a second hole that is present between the plurality of second ribs in the circumferential direction.

6 . The gear according to claim 5 , wherein a central line between the first hole and the second hole in the axial direction coincides with the central line of the gear tooth in the axial direction.

7 . A steering system comprising:
an electric motor to be driven based on steering of a steering member; and a speed reducer including the gear according to claim 1 and configured to reduce a speed of output rotation of the electric motor by the gear and transmit the output rotation to a steering mechanism.

Assignees

• Jtekt Corp

Inventors

• Kikuchi Arata
• Okumura Koji

Classifications

• F16H55/17

  Toothed wheels (worm wheels F16H55/22; chain wheels F16H55/30) · CPC title

• F16H55/22

  for transmissions with crossing shafts, especially worms, worm-gears · CPC title

• F16H2055/065

  Moulded gears, e.g. inserts therefor · CPC title

• B62D5/0409

  Electric motor acting on the steering column · CPC title

• B62D5/0454 Primary

  Worm gears · CPC title