Worm and rotating device

Patent metadata

Field	Value
Publication number	US-11719324-B2
Application number	US-201917422277-A
Country	US
Kind code	B2
Filing date	Dec 24, 2019
Priority date	Jan 16, 2019
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

A worm ( 40 ) according to an embodiment is a worm made of resin and formed by injection molding. The worm includes a gear portion ( 40 a ), a cavity ( 40 c ) having an axis being a longitudinal axis ( 40 d ) of the worm being formed at the gear portion, and a top portion ( 40 b ) formed at a first end portion of the gear portion in a direction of the longitudinal axis. A plurality of recesses ( 40 e ) including a hole portion communicating with the cavity are formed at the top portion in a radial direction, and are located on an outer peripheral portion side of the gear portion with respect to the cavity.

First claim

The invention claimed is:

1. A worm made of resin and formed by injection molding, the worm comprising:
a gear portion, wherein the gear portion includes a cavity having an axis being a longitudinal axis of the worm;
a first end portion and a second end portion, the first end portion being open in the longitudinal axis of the worm,
a top portion is formed at the second end portion of the gear portion in a direction of the longitudinal axis of the worm,
a plurality of recesses including a hole portion communicating with the cavity are formed at the top portion in a radial direction, the plurality of recesses being located on an outer peripheral portion side of the gear portion with respect to the cavity,
the recess including wall portions having a first wall portion extending in a radial direction and a second wall portion extending in the direction of the longitudinal axis of the worm,
the hole portion is formed at the second wall portion,
the hole portion is arranged between a surface of the top portion and the first wall portion in the direction of the longitudinal axis of the worm, the surface of the top portion opposing the cavity,
the first wall portion is arranged in the first end portion side with respect to the surface of the top portion in the direction of the longitudinal axis of the worm, and
the hole portion is open in a direction toward the outer peripheral portion side of the gear portion from the cavity in a radial direction.

2. The worm according to claim 1 , wherein
the top portion includes an outer surface to be supported by another member, and
the worm rotates in a circumferential direction of the top portion as a rotation direction, with the outer surface in contact with the other member.

3. The worm according to claim 1 , wherein
in a circumferential direction, the plurality of recesses are formed at equal intervals in the top portion.

4. A worm comprising a resin member, wherein
the resin member includes:
an inner peripheral portion forming a cavity having a longitudinal axis, and
an outer peripheral portion, a helical tooth being formed at the outer peripheral portion,
in a direction of the longitudinal axis, the resin member includes a first end portion being an open end portion and a second end portion,
an axis of the outer peripheral portion is the longitudinal axis,
three or more recesses are formed in an outer surface of the second end portion of the resin member in the direction of the longitudinal axis,
the three or more recesses each include a hole portion in communication with the cavity,
the recess includes wall portions having a first wall portion extending in a radial direction and a second wall portion extending in the direction of the longitudinal axis,
the hole portion is formed at the second wall portion,
the hole portion is arranged between a surface of the second end portion and the first wall portion in the direction of the longitudinal axis, the surface of the second end portion opposing the cavity,
the first wall portion is arranged in the first end portion side with respect to the surface of the second end portion in the direction of the longitudinal axis, and
the hole portion is open in a direction toward the outer peripheral portion from the cavity in a radial direction.

5. The worm according to claim 4 , wherein
the resin member includes the outer surface to be supported by another member, and
the worm rotates in a circumferential direction of the resin member as a rotation direction, with the outer surface in contact with the other member.

6. The worm according to claim 5 , wherein
the three or more recesses are formed at equal intervals in a circumferential direction.

7. A rotating device, comprising:
the worm according to claim 1 and a gear meshed with the worm;
a motor having an output shaft disposed in the cavity; and
a casing accommodating the motor, the gear, and the worm, wherein
the worm rotates in a circumferential direction of the worm as a rotation direction, with a second end portion of the worm in contact with the casing.

8. The rotating device according to claim 7 , wherein
in a radial direction, the hole portion is positioned so as to oppose the output shaft of the motor.

Assignees

• Minebea Mitsumi Inc

Inventors

• Hirabayashi Koichiro

Classifications

• F16H55/22 Primary

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

• F16H25/16

  for interconverting rotary motion and oscillating motion · CPC title

• F16H55/06 Primary

  Use of materials; Use of treatments of toothed members or worms to affect their intrinsic material properties · CPC title

• F16H2025/249

  Materials or coatings for screws or nuts · CPC title

• F16H1/16

  comprising worm and worm-wheel · CPC title