Vehicle electric braking device

Patent metadata

Field	Value
Publication number	US-9599177-B2
Application number	US-201414763466-A
Country	US
Kind code	B2
Filing date	Jan 27, 2014
Priority date	Jan 25, 2013
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

Rotational motion of a shaft member rotationally driven by a motor is converted by a screw member into translational motion of a pressing member. An outer periphery of a cap member is brought into slide contact with a first cylindrical part of the pressing member so that the cap member is relatively movable in an axial direction of the pressing member and is relatively unrotatable about its axis. An inner periphery of the cap member is brought into slide contact with a second cylindrical part of the shaft member so that the cap member is relatively movable in an axial direction of the shaft member and is relatively rotatable about its axis. The first cylindrical part, the second cylindrical part, and the cap member partition a storage chamber connected to one end of the screw member, and a lubricant for lubricating the screw member is filled inside the storage chamber.

First claim

The invention claimed is:

1. A vehicle electric braking device configured to press a friction member using an electric motor against a rotation member fixed to a wheel of a vehicle, to thereby generate a braking torque for the wheel,
the vehicle electric braking device comprising:
a pressing member configured to press the friction member against the rotation member, the pressing member including a first cylindrical part on an inner periphery thereof;
a shaft member to be rotationally driven by the electric motor, the shaft member including, on an outer periphery thereof, a second cylindrical part overlapping the first cylindrical part in an axial direction of the shaft member;
a screw member configured to convert a rotational motion of the shaft member into a translational motion of the pressing member;
a cap member that is brought into slide contact with the first cylindrical part on an outer periphery of the cap member so that the cap member is relatively movable in an axial direction of the pressing member with respect to the pressing member, and is brought into slide contact with the second cylindrical part on an inner periphery of the cap member so that the cap member is relatively movable in the axial direction of the shaft member with respect to the shaft member, wherein the cap member being relatively rotatable about an axis of the shaft member with respect to at least one of the first cylindrical part or the second cylindrical part; and
a storage chamber partitioned by the first cylindrical part, the second cylindrical part, and the cap member, connected to one end of the screw member, and filled with a lubricant for lubricating the screw member.

2. A vehicle electric braking device according to claim 1 ,
wherein the pressing member has a cup shape including an internal space that is open on one side in the axial direction and closed on another side in the axial direction, and an inner peripheral surface of a side wall part of the cup shape corresponds to the first cylindrical part,
wherein one end part of the shaft member is arranged in the internal space, and an outer peripheral surface of the one end part of the shaft member corresponds to the second cylindrical part, and
wherein the storage chamber is arranged in the internal space in a region on an opposite side of the opening with respect to the cap member.

3. A vehicle electric braking device configured to press a friction member using an electric motor against a rotation member fixed to a wheel of a vehicle, to thereby generate a braking torque for the wheel,
the vehicle electric braking device comprising:
a pressing member configured to press the friction member against the rotation member;
a shaft member to be rotationally driven by the electric motor;
a screw member configured to convert a rotational motion of the shaft member into a translational motion of the pressing member; and
a sealed chamber, which is a sealed space connected to one end of the screw member, the sealed space being filled with a lubricant for lubricating the screw member,
wherein the lubricant moves between the sealed chamber and the screw member via a thread clearance of engaged threads of the screw member so as to absorb volume change of the sealed chamber, which is generated by the rotation of the shaft member.

4. A vehicle electric braking device according to claim 3 ,
wherein the pressing member has a cup shape including an internal space that is open on one side in an axial direction of the pressing member and closed on another side in the axial direction,
wherein one end part of the shaft member is arranged in the internal space, and
wherein the sealed chamber is partitioned by an inner wall surface of the cup shape of the pressing member or a wall surface of the one end part of the shaft member.

5. A vehicle electric braking device configured to press a friction member using an electric motor against a rotation member fixed to a wheel of a vehicle, to thereby generate a braking torque for the wheel,
the vehicle electric braking device comprising:
a pressing member configured to press the friction member against the rotation member, and including a first cylindrical part on an inner periphery thereof;
a shaft member to be rotationally driven by the electric motor, and including, on an outer periphery thereof, a second cylindrical part overlapping the first cylindrical part in an axial direction of the shaft member, and on an inner periphery thereof, a third cylindrical part;
a screw member arranged inside the third cylindrical part, and configured to convert a rotational motion of the shaft member into a translational motion of the pressing member; and
a storage chamber partitioned by the first cylindrical part and the second cylindrical part, connected to one end of the screw member, and filled with a lubricant for lubricating the screw member.

6. A vehicle electric braking device according to claim 5 ,
wherein the pressing member has a first cup shape including a first internal space that is open on one side in the axial direction and closed on another side in the axial direction, and an inner peripheral surface of a side wall part of the first cup shape corresponds to the first cylindrical part,
wherein one end part of the shaft member is arranged in the first internal space,
wherein the one end part of the shaft member has a second cup shape including a second internal space that is open at an end part in the axial direction and closed on an opposite side of the end part in the axial direction, and an outer peripheral surface and an inner peripheral surface of a side wall part of the second cup shape respectively correspond to the second cylindrical part and the third cylindrical part,
wherein the storage chamber is arranged in the first internal space,
and
wherein the screw member is arranged in the second internal space.

7. A vehicle electric braking device according to claim 3 ,
wherein the screw member comprises a bolt threadedly engaged with a nut, the bolt fixed to one of the shaft member or the pressing member and the nut fixed to an other of the shaft member or the pressing member.

Assignees

• Yasui Yoshiyuki
• Yukoku Shinichiro
• EMURA Naomi
• Advics Co Ltd

Inventors

• Yasui Yoshiyuki
• Yukoku Shinichiro
• EMURA Naomi

Classifications

• F16D55/226

  in which the common actuating member is moved axially {, e.g. floating caliper disc brakes} · CPC title

• F16H57/0497 Primary

  Screw mechanisms · CPC title

• F16H25/24

  Elements essential to such mechanisms, e.g. screws, nuts (F16H25/22 takes precedence) · CPC title

• F16D2121/24

  using motors · CPC title

• F16D55/225

  the braking members being brake pads · CPC title