Worm gear

Patent metadata

Field	Value
Publication number	US-9618082-B2
Application number	US-201414184545-A
Country	US
Kind code	B2
Filing date	Feb 19, 2014
Priority date	Nov 4, 2011
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A worm gear includes a worm formed with a through hole through which a shaft transmitting the rotation of a motor is inserted, and a worm wheel configured to mesh with the worm and transmit the rotation to an output shaft. Given that a normal pitch is denoted by E and a width of a recess in the direction of a worm axis by H, the worm is configured such that H/E≧0.6 (1) is met.

First claim

What is claimed is:

1. A worm gear comprising:
a worm formed with a through hole through which a shaft transmitting the rotation of a motor is inserted, the shaft having a diameter;
a worm wheel configured to mesh with the worm and transmit the rotation to an output shaft; and
a grease pool having an area,
wherein the diameter of the shaft is φ3.0-5.0 mm and the area of the grease pool is 0.20 mm 2 or more,
wherein the worm wheel is formed of a resin material,
wherein the worm is formed of a metallic material, and
wherein, given that a normal pitch is denoted by E and a width of a recess formed to extend from the root circle toward a center of a worm axis, in the direction of a worm axis by H, the worm is configured such that
H/E≧ 0.6  (expression 1)

is met.

2. A worm gear comprising:
a worm formed with a through hole through which a shaft transmitting the rotation of a motor is inserted, the shaft having a diameter;
a worm wheel configured to mesh with the worm and transmit the rotation to an output shaft; and
a grease pool having an area,
wherein the diameter of the shaft is (10.0-5.0 mm and the area of the grease pool is 0.20 mm 2 or more,
wherein the worm wheel is formed of a resin material,
wherein the worm is formed of a metallic material, and
wherein, given that a normal pitch is denoted by E, a radius of a root circle by F, a depth, from the root circle, of a recess formed to extend from the root circle toward a center of a worm axis by G, a width of the recess in the direction of the worm axis by H, and an inner diameter of the through hole by J, the worm is configured such that
H/E≧ 0.6,  (expression 1)

( F−J/ 2)×0.25≧ G≧E≧ 0.1  (expression 2)

are met.

3. A worm gear comprising:
a worm formed with a through hole through which a shaft transmitting the rotation of a motor is inserted, the shaft having a diameter;
a worm wheel configured to mesh with the worm and transmit the rotation to an output shaft; and
a grease pool having an area,
wherein the diameter of the shaft is φ3.0-5.0 mm and the area of the grease pool is 0.20 mm 2 or more,
wherein the worm wheel is formed of a resin material,
wherein the worm is formed of a metallic material, and
wherein, given that a normal pitch is denoted by E, a radius of a root circle by F, a depth, from the root circle, of a recess formed to extend from the root circle toward a center of a worm axis by G, a width of the recess in the direction of the worm axis by H, and an inner diameter of the through hole by J, the worm is configured such that
H/E≧ 0.6,  (expression 3)

F−G−J/ 2≧ J/ 3  (expression 4)

are met.

4. The worm gear according to claim 1 ,
wherein the worm wheel is integrated with the output shaft.

5. The worm gear according to claim 1 ,
wherein a tooth tip of the worm has a length of less than 0.2 mm.

6. The worm gear according to claim 2 ,
wherein the worm wheel is integrated with the output shaft.

7. The worm gear according to claim 3 ,
wherein the worm wheel is integrated with the output shaft.

8. The worm gear according to claim 2 ,
wherein a tooth tip of the worm has a length of less than 0.2 mm.

9. The worm gear according to claim 3 ,
wherein a tooth tip of the worm has a length of less than 0.2 mm.

10. The worm gear according to claim 4 ,
wherein a tooth tip of the worm has a length of less than 0.2 mm.

Assignees

• Mabuchi Motor Co

Inventors

• Itou Kiyoto
• Yamamoto Kazuyuki

Classifications

• F16H57/0464

  Grease lubrication · CPC title

• Y10T74/19828

  Worm · CPC title

• F16H1/16 Primary

  comprising worm and worm-wheel · CPC title

• F16H57/0498

  Worm gearings · CPC title

• F16H55/0853

  Skewed-shaft arrangement of the toothed members (F16H55/082, F16H55/0826, F16H55/0833, F16H55/084 take precedence) · CPC title