Bearing unit and speed reducer-equipped motor

Patent metadata

Field	Value
Publication number	US-11892071-B2
Application number	US-202218042769-A
Country	US
Kind code	B2
Filing date	Oct 14, 2022
Priority date	Jan 27, 2022
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

A bearing unit includes: a thrust damper extendable in an axial direction of a shaft placed in a gearbox, the movement of which toward one side in the axial direction is regulated; a shaft receiver component held by the thrust damper on the other side of the thrust damper in the axial direction; a metal holder that holds the shaft receiver component in such a manner as to be detachable in the axial direction; and an oilless metal held by the metal holder and placed on the other side of the shaft receiver component, in which the thrust damper, the shaft receiver component, the metal holder, and the oilless metal are integrated all together before being incorporated into the gearbox.

First claim

The invention claimed is:

1. A bearing unit, comprising:
a thrust damper extendable in an axial direction of a shaft placed in a gearbox, the movement of which toward one side in the axial direction is regulated;
a shaft receiver component held by the thrust damper on the other side of the thrust damper in the axial direction;
a metal holder that holds the shaft receiver component in such a manner as to be detachable in the axial direction; and
an oilless metal held by the metal holder and placed on the other side of the shaft receiver component,
wherein the thrust damper, the shaft receiver component, the metal holder, and the oilless metal are integrated all together before being incorporated into the gearbox,
the metal holder includes a press-fit end portion press-fitted and fixed in a storage portion of the gearbox, and
the shaft receiver component is light press-fitted in the metal holder before being incorporated into the gearbox, is pressed toward the one side by the shaft after being incorporated into the gearbox to terminate a light press-fitted state in the metal holder, and is held in such a manner as to be slidable in the axial direction relative to the metal holder.

2. The bearing unit according to claim 1 , wherein
the shaft receiver component includes:
a damper-side press-fit portion press-fitted in an inner hole of the thrust damper in a tubular shape;
a flange portion in contact with an end surface on the other side of the thrust damper; and
a holder-side press-fit portion that extends from the flange portion toward the other side, and has a tubular surface,

the metal holder includes:
a protruding piece that extends from the press-fit end portion toward the one side, to which the tubular surface of the holder-side press-fit portion is light press-fitted; and
a holding piece that extends from the press-fit end portion toward the one side, and holds the oilless metal, and

the oilless metal is placed on the one side of the press-fit end portion of the metal holder.

3. The bearing unit according to claim 2 , wherein
the shaft receiver component includes a guide portion that extends from the holder-side press-fit portion toward the other side, and has a tubular surface of a smaller diameter than that of the holder-side press-fit portion, and
the shaft receiver component is pressed toward the one side by the shaft after being incorporated into the gearbox to terminate the light press-fitted state in the metal holder, and the guide portion is held in such a manner as to be slidable in the axial direction relative to the protruding piece of the metal holder.

4. The bearing unit according to claim 2 , wherein
the holding piece of the metal holder is shorter in the axial direction and thinner in a radial direction than the protruding piece of the metal holder.

5. The bearing unit according to claim 4 , wherein
the press-fit end portion of the metal holder includes, in a part of an outer peripheral surface thereof, a positioning surface formed into a plane surface, and
the metal holder is formed in such a manner that the protruding piece is placed in a position that receives radial load acting on the shaft upon being press-fitted and fixed with the positioning surface aligned with a predetermined position of the storage portion.

6. The bearing unit according to claim 2 , wherein
the metal holder includes a plurality of the protruding pieces and a plurality of the holding pieces, and
the protruding pieces and the holding pieces are alternately provided in a circumferential direction, and form an inner peripheral surface surrounding the oilless metal.

7. The bearing unit according to claim 2 , wherein
the press-fit end portion of the metal holder has an annular shape, and includes a shaft guide surface of which an inner peripheral surface reduces in an inner diameter from an end surface on the other side toward the one side.

8. The bearing unit according to claim 2 , wherein in a cross section of the metal holder cut along the axial direction,
a portion, which is closer to the press-fit end portion, of an inner surface, which faces the oilless metal, of the protruding piece has a curved surface that curves along an outer peripheral surface of the oilless metal, and
a portion, which is closer to the press-fit end portion, of an inner surface, which faces the oilless metal, of the holding piece extends not along the outer peripheral surface of the oilless metal but in the axial direction.

9. The bearing unit according to claim 2 , wherein
a shaft contact portion that comes into contact with the shaft is formed on an end surface on the other side of the shaft receiver component, and
the shaft contact portion has a shape that allows storage of grease.

10. A speed reducer-equipped motor comprising:
a motor unit including a shaft;
a reduction drive including a worm that rotates integrally with the shaft of the motor unit, and a worm wheel that meshes with the worm; and
a gearbox to which the motor unit is attached, the gearbox storing the reduction drive,
wherein the bearing unit according to claim 1 is used at an end portion of the shaft placed in the gearbox.

Assignees

• Mabuchi Motor Co

Inventors

• Yamamoto Kazuyuki

Classifications

• F16H57/021 Primary

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

• F16H55/24

  Special devices for taking up backlash · CPC title

• H02K7/081 Primary

  specially adapted for worm gear drives (H02K7/09 takes precedence) · CPC title

• F16H2057/0213

  Support of worm gear shafts · CPC title

• F16C17/08

  for supporting the end face of a shaft or other member, e.g. footstep bearings · CPC title