Gearbox, motor with speed reducer, and method for manufacturing gearbox

Patent metadata

Field	Value
Publication number	US-10090728-B2
Application number	US-201615356443-A
Country	US
Kind code	B2
Filing date	Nov 18, 2016
Priority date	Jun 10, 2014
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A gearbox includes: a gearbox main body made of resin that constitutes a part of a speed reducer to which a motor is mounted; and a terminal that conducts power supplied from an external source to the motor. The gearbox main body includes a through hole formed to correspond to a mold that is used to maintain a position of the terminal while the terminal is being integrated with the gearbox main body by insert molding. The through hole may function as a vent hole in the gearbox main body.

First claim

The invention claimed is:

1. A gearbox comprising:
a gearbox main body made of resin that constitutes a part of a speed reducer to which a motor is mounted; and
a terminal that conducts power supplied from an external source to the motor, wherein
the gearbox main body includes a through hole formed to correspond to a mold that is used to maintain a position of the terminal while the terminal is being integrated with the gearbox main body by insert molding.

2. The gearbox according to claim 1 , wherein
the through hole functions as a vent hole in the gearbox main body.

3. The gearbox according to claim 2 , wherein the gearbox main body includes:
a worm wheel housing that houses a worm wheel of the speed reducer;
a motor mount formed with an opening through which a worm fixed to a motor shaft is inserted and having the motor mounted thereto; and
a power feeding opening to which an external terminal is connected, wherein
the terminal constitutes a power feeding channel between the motor mount and the power feeding opening, and
the through hole is provided in a region adjacent to the motor mount and at a position where a difference in a pressure inside the motor mount and a pressure outside the motor is eliminated.

4. The gearbox according to claim 3 , wherein
the through hole is provided at a position where a space isolated from the worm wheel housing by a wall and formed by removing a mold member used to support the terminal and a space outside the motor communicate.

5. The gearbox according to claim 2 , further comprising:
a semipermeable membrane provided to cover the through hole, wherein the through hole is polygonal,
an annular concave part is formed around the through hole to face the front, and
the semipermeable membrane is mounted to the concave part.

6. The gearbox according to claim 1 , wherein
the terminal includes a first terminal and a second terminal, and
the through hole is formed to correspond to a mold member used to maintain positions of the first terminal and the second terminal.

7. The gearbox according to claim 1 , wherein
the gearbox is configured such that a minimum distance between the through hole and the terminal is 0.5 mm or less when the gearbox main body is seen in an axial direction of a rotation axis of the worm wheel.

8. A motor with a speed reducer, comprising:
the gearbox according to claim 1 ;
a worm wheel; and
a motor in which a worm in mesh with the worm wheel is fixed to a shaft.

9. A method of manufacturing a gearbox whereby a gearbox main body of a speed reducer to which a motor is mounted is manufactured by integral molding, using a mold,
wherein a terminal for establishing electric conduction between two openings of the gearbox main body is integrated with the gearbox main body by insert molding such that the terminal is sandwiched and fixed by a plurality of molds,
wherein the plurality of molds include a mount mold for mounting the terminal and a housing mold for forming a side wall of a worm wheel housing for housing a worm wheel of the speed reducer, and the terminal is insert molded so that terminal mounted to the mount mold is not in contact with a part of the housing mold that corresponds to the worm wheel housing.

10. The method of manufacturing a gearbox according to claim 9 , wherein a vent hole is formed to correspond to one of the plurality of molds.

Assignees

• Mabuchi Motor Co

Inventors

• Mitsumizo Takao
• Hirano Yuuki
• Yuhi Toshiya
• Kouno Hiroki
• Kikuchi Satoshi

Classifications

• H02K15/14

  Casings; Enclosures; Supports · CPC title

• H02K7/1166

  comprising worm and worm-wheel (structural association with bearings specially adapted for worm gear drives H02K7/081) · CPC title

• H02K15/12

  Impregnating, moulding insulation, heating or drying of windings, stators, rotors or machines · CPC title

• H02K15/0062

  Electricity · mapped topic

• H02K5/02

  Casings or enclosures characterised by the material thereof · CPC title