Reduction gear and geared motor

Patent metadata

Field	Value
Publication number	US-11525503-B2
Application number	US-202117153503-A
Country	US
Kind code	B2
Filing date	Jan 20, 2021
Priority date	Jan 31, 2020
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A reduction gear configured to decelerate and output rotation of a motor by two-stage planetary gear mechanisms disposed side by side in an axial direction includes: a case made of resin, the case being formed into a cylindrical shape in which the two-stage planetary gear mechanisms are incorporated, and having at least one of a lid portion and a bottom portion provided at each of both axial ends; and a reinforcing component that is formed of a material having a Young's modulus higher than a Young's modulus of a material of the case. The reinforcing component extends along at least a part of an inner peripheral surface in an axial central portion of the case.

First claim

What is claimed is:

1. A reduction gear configured to decelerate and output rotation of a motor by two-stage planetary gear mechanisms disposed side by side in an axial direction, the reduction gear comprising:
a case made of resin, the case being formed into a cylindrical shape in which the two-stage planetary gear mechanisms are incorporated, and having at least one of a lid portion and a bottom portion provided at each of both axial ends; and
a reinforcing component that is formed of a material having a Young's modulus higher than a Young's modulus of a material of the case and extends along at least a part of an inner peripheral surface in an axial central portion of the case.

2. The reduction gear according to claim 1 , wherein the reinforcing component has a ring shape extending over an entire circumference of the case in the axial central portion of the case.

3. The reduction gear according to claim 2 , wherein the reinforcing component is located between pinion gears of the two-stage planetary gear mechanisms.

4. The reduction gear according to claim 2 ,
wherein the inner peripheral surface of the case includes a small-diameter inner peripheral surface and a large-diameter inner peripheral surface having different inner diameters from each other in the axial direction, and a tapered surface connecting the small-diameter inner peripheral surface and the large-diameter inner peripheral surface and inclined in the axial direction, and
the reinforcing component is press-fitted into the case and disposed at a position in contact with a boundary line between the large-diameter inner peripheral surface and the tapered surface.

5. The reduction gear according to claim 2 , wherein the case has a bottomed cylindrical shape having the bottom portion at one axial end and the lid portion at another axial end, and is attached to the motor in a direction in which the bottom portion is located on a motor side.

6. The reduction gear according to claim 5 , wherein the lid portion is press-fitted into an opening at the other axial end of the case.

7. The reduction gear according to claim 1 , wherein the reinforcing component is located between pinion gears of the two-stage planetary gear mechanisms.

8. The reduction gear according to claim 7 ,
wherein the inner peripheral surface of the case includes a small-diameter inner peripheral surface and a large-diameter inner peripheral surface having different inner diameters from each other in the axial direction, and a tapered surface connecting the small-diameter inner peripheral surface and the large-diameter inner peripheral surface and inclined in the axial direction, and
the reinforcing component is press-fitted into the case and disposed at a position in contact with a boundary line between the large-diameter inner peripheral surface and the tapered surface.

9. The reduction gear according to claim 7 , wherein the case has a bottomed cylindrical shape having the bottom portion at one axial end and the lid portion at another axial end, and is attached to the motor in a direction in which the bottom portion is located on a motor side.

10. The reduction gear according to claim 9 , wherein the lid portion is press-fitted into an opening at the other axial end of the case.

11. The reduction gear according to claim 1 ,
wherein the inner peripheral surface of the case includes a small-diameter inner peripheral surface and a large-diameter inner peripheral surface having different inner diameters from each other in the axial direction, and a tapered surface connecting the small-diameter inner peripheral surface and the large-diameter inner peripheral surface and inclined in the axial direction, and
the reinforcing component is press-fitted into the case and disposed at a position in contact with a boundary line between the large-diameter inner peripheral surface and the tapered surface.

12. The reduction gear according to claim 11 , wherein the case has a bottomed cylindrical shape having the bottom portion at one axial end and the lid portion at another axial end, and is attached to the motor in a direction in which the bottom portion is located on a motor side.

13. The reduction gear according to claim 12 , wherein the lid portion is press-fitted into an opening at the other axial end of the case.

14. The reduction gear according to claim 1 , wherein the case has a bottomed cylindrical shape having the bottom portion at one axial end and the lid portion at another axial end, and is attached to the motor in a direction in which the bottom portion is located on a motor side.

15. The reduction gear according to claim 14 , wherein the lid portion is press-fitted into an opening at the other axial end of the case.

16. A geared motor comprising:
a reduction gear configured to decelerate and output rotation of a motor by two-stage planetary gear mechanisms disposed side by side in an axial direction, the reduction gear comprising:
a case made of resin, the case being formed into a cylindrical shape in which the two-stage planetary gear mechanisms are incorporated, and having at least one of a lid portion and a bottom portion provided at each of both axial ends; and
a reinforcing component that is formed of a material having a Young's modulus higher than a Young's modulus of a material of the case and extends along at least a part of an inner peripheral surface in an axial central portion of the case; and
the motor having a shaft integrally rotating with a sun gear of the planetary gear mechanism in a first stage of the reduction gear.

Assignees

• Mabuchi Motor Co

Inventors

• Suwa Masakazu
• Mitsumizo Takao

Classifications

• F16H57/032

  characterised by the materials used · CPC title

• F16H2057/02034

  Gearboxes combined or connected with electric machines · CPC title

• F16H1/46

  Systems consisting of a plurality of gear trains each with orbital gears, {i.e. systems having three or more central gears} · CPC title

• F16H2057/02082

  for application in vehicles other than propelling, e.g. adjustment of parts · CPC title

• F16H57/021

  Shaft support structures, e.g. partition walls, bearing eyes, casing walls or covers with bearings · CPC title