Electric parking brake driving device and electric parking brake device

Patent metadata

Field	Value
Publication number	US-2016200294-A1
Application number	US-201414912746-A
Country	US
Kind code	A1
Filing date	Aug 26, 2014
Priority date	Aug 27, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

Provided are a compact, highly reliable electric parking brake driving device and an electric parking brake device. This electric parking brake driving device transmits a driving force generated by an electric motor to a parking brake actuator via a speed reduction mechanism, and makes the wheels generate a braking force. A gear body of the electric parking brake driving device is formed by joining a lower body and an upper body. A bracket member is fixed to the lower body, and the electric motor is positioned in the radial direction by engaging with the bracket member. A rubber disk is placed between the lower end surface of the electric motor and the bottom surface of the lower body, and the rubber disk impels the electric motor toward the bracket member in the direction of the rotation axis.

First claim

1 . An electric parking brake driving device for driving a parking brake actuator in which rotation motion of a rotating member is converted to linear motion, the linear motion is transmitted to a moving member and a brake pad impelled by the moving member presses a disk rotated together with a wheel to generate a braking force on the wheel, the device comprising:
a gear body formed by joining a first piece and a second piece; a mounting member fixed on an inner periphery of the first piece; an electric motor positioned in the gear body in a predetermined direction by engaging or being integrated with the mounting member; a pressing member arranged between an inner peripheral surface of the first piece and the electric motor and impelling the electric motor toward the mounting member; and a speed reduction mechanism housed in the gear body and transmitting a driving force generated by the electric motor to the rotating member.

2 . The electric parking brake driving device according to claim 1 ,
wherein the speed reduction mechanism includes: a driving gear fixed to an output shaft of the electric motor; a first gear shaft positioned in the predetermined direction by engaging with the mounting member and mounted in the gear body; and a first driven gear formed on the first gear shaft, having more teeth than the driving gear, engaging with the driving gear, and connected to the rotating member, so that the first driven gear transmits the rotation of the electric motor while reducing the speed thereof to the rotating member.

3 . The electric parking brake driving device according to claim 2 ,
wherein the electric motor has a motor housing, a fitting portion projecting from one end surface of the motor housing in the direction of the rotation axis, the output shaft projecting in the axial direction from a projecting end surface of the fitting portion, wherein the mounting member is arranged so as to face the one end surface of the motor housing and has a positioning hole, the positioning hole being fitted to an outer circumferential surface of the fitting portion, so that the electric motor being positioned relative to the mounting member in the radial direction, wherein the pressing member impels the other end surface of the motor housing toward the mounting member to make the one end surface abut on the mounting member.

4 . The electric parking brake driving device according to claim 3 ,
wherein an elastic body holding portion projects from the other end surface of the motor housing, wherein the pressing member is formed of a rubber material in a disk shape having a holding hole at a center thereof, and is arranged between the inner peripheral surface of the first piece and the other end surface of the motor housing so that the elastic body holding portion is fitted in the holding hole.

5 . The electric parking brake driving device according to claim 2 ,
wherein the speed reduction mechanism comprising: a transmission gear provided on the first gear shaft and rotated integrally with the first driven gear; a second gear shaft mounted in the gear body; a second driven gear formed on the second gear shaft, having more teeth than the transmission gear, and engaging with the transmission gear; a sun gear provided on the second gear shaft and rotated integrally with the second driven gear; a plurality of planetary gears engaging with the sun gear and revolving around an outer circumference of the sun gear by rotation of the sun gear; a ring gear arranged around the planetary gears, engaging with the planetary gears on an inner circumferential surface thereof, and being unrotatable by engaging with the gear body; and a carrier member connecting the planetary gears, connected to the rotating member, and rotated by revolution of the planetary gears, so that the carrier member transmits the rotation of the sun gear while reducing the speed thereof to the rotating member.

6 . An electric parking brake device comprising:
a brake housing mounted on a vehicle body; a moving member mounted in the brake housing so as to be movable in the axial direction and to be unrotatable; a brake pad arranged between a disk rotated together with a wheel and the moving member; a gear body formed by joining a first piece and a second piece and mounted to the brake housing; an electric motor mounted in the gear body; a speed reduction mechanism housed in the gear body and transmitting a driving force generated by the electric motor; and a rotating member engaging with the moving member, driven by the electric motor via the speed reduction mechanism to move the moving member in the axial direction, and impelling the brake pad toward the disk via the moving member, wherein a mounting member is fixed on an inner periphery of the first piece, wherein the electric motor is positioned in the gear body in a predetermined direction by engaging or being integrated with the mounting member, wherein a pressing member is arranged between an inner peripheral surface of the first piece and the electric motor, and impels the electric motor toward the mounting member.

Assignees

• Advics Co Ltd

Inventors

• Takeo Yuichi

Classifications

• B60T1/065

  employing disc (B60T1/062 takes precedence) · CPC title

• F16H1/04

  involving only two intermeshing members · CPC title

• F16D65/18

  adapted for drawing members together {, e.g. for disc brakes} · CPC title

• B60T7/00 Primary

  Brake-action initiating means · CPC title

• F16H1/28

  with gears having orbital motion · CPC title