Clutch device having a back torque limiter

Patent metadata

Field	Value
Publication number	US-9689439-B2
Application number	US-201615015524-A
Country	US
Kind code	B2
Filing date	Feb 4, 2016
Priority date	Feb 9, 2015
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

A clutch device includes a slipper cam mechanism which releases a back torque by moving a clutch center in an axial direction, and a plunger mechanism provided to the clutch center. The plunger mechanism engages with a movement restricting portion until a rotational speed of the clutch center reaches a threshold value thus restricting the movement of the clutch center in the clutch axial direction, and the plunger mechanism is operated by a centrifugal force when the rotational speed of the clutch center exceeds the threshold value such that it disengages from the movement restricting portion.

First claim

We claim:

1. A clutch device comprising:
a first clutch member;
a second clutch member;
a third clutch member supported on the second clutch member in an axially movable and relatively rotatable manner;
a first friction plate supported on the first clutch member in an axially movable and integrally rotatable manner;
a second friction plate supported on the third clutch member in an axially movable and integrally rotatable manner, such that the second friction plate overlaps with the first friction plate;
a pressure receiving plate mounted on the second clutch member in a state where the pressure receiving plate opposedly faces one side of an assembled body formed of the first friction plate and the second friction plate in a clutch axial direction;
a pressurizing plate provided in a state where the pressurizing plate faces an opposite side of the assembled body in the clutch axial direction and is movable toward the pressure receiving plate in the clutch axial direction;
a clutch spring which biases the pressurizing plate to a pressure receiving plate side;
a slipper cam mechanism provided between the second clutch member and the third clutch member, and configured such that in a state where a back torque is applied to the third clutch member from the second clutch member, the slipper cam mechanism moves the third clutch member along with the pressurizing plate in the clutch axial direction to reduce the back torque transmitted to the first clutch member; and
a movement restricting mechanism provided to the third clutch member which selectively limits movement of the third clutch member in the clutch axial direction, wherein the movement restricting mechanism is moved between movement restricting and movement non-restricting positions thereof by a centrifugal force generated by rotation of the third clutch member such that the movement restricting mechanism restricts axial movement of the third clutch member until a rotational speed of the third clutch member reaches a threshold value, but does not restrict the axial movement of the third clutch member when the rotational speed of the third clutch member exceeds the threshold value, and further including
a power transmission shaft supporting the clutch device;
a lock nut fixing the second clutch member to the power transmission shaft; and
a washer member which forms the movement restricting portion arranged between the lock nut and the second clutch member,
wherein the movement restricting mechanism includes a plunger which is advanceable and retractable between the movement restricting position of the movement restricting mechanism where the plunger overlaps with the washer member as viewed in an axial direction, and the movement non-restricting position of the movement restricting mechanism where the plunger does not overlap with the washer member as viewed in an axial direction, and the plunger contacts the washer member in the clutch axial direction when the movement restricting mechanism is in the movement restricting position thereof, thus restricting the movement of the third clutch member in the clutch axial direction,
wherein the washer member has a washer-side contact surface which is inclined such that the closer to an outer peripheral side the washer-side contact surface is disposed with respect to an axially orthogonal plane, the farther away from an axial center of the plunger the washer-side contact surface is positioned, and the plunger has a plunger-side contact surface which is inclined so as to conform to the washer-side contact surface, and
wherein the washer-side contact surface and the plunger-side contact surface are each formed into a stepped shape.

2. The clutch device according to claim 1 , wherein the movement restricting mechanism engages with a movement restricting portion when restricting the axial movement of the third clutch member, and does not engage with the movement restricting portion when not restricting the axial movement of the third clutch member.

3. The clutch device according to claim 1 , wherein the third clutch member is movable in the clutch axial direction between a first engaging position where the third clutch member is separated from the pressurizing plate and is brought into contact with the second clutch member and a second engaging position where the third clutch member is separated from the second clutch member and is brought into contact with the pressurizing plate for moving the pressurizing plate toward a side opposite to the pressure receiving plate, and the clutch device further comprises a sub-spring provided between the second clutch member and the third clutch member, the sub-spring has a smaller spring load than that of the clutch spring and biases the third clutch member to the second clutch member in a direction toward the second engaging position of the third clutch member, and the sub-spring is arranged at a position where the sub-spring overlaps with the plunger as viewed in the clutch axial direction.

4. The clutch device according to claim 1 , wherein the washer-side contact surface and the plunger-side contact surface each have a curved surface portion on at least one of a crest portion and a valley portion which form a stepped shape thereof, respectively.

5. The clutch device according to claim 4 , wherein the washer-side contact surface is formed as an arcuate streak extending along a circumferential direction of the washer member, and the plunger-side contact surface is formed as a straight-line shaped streak orthogonal to an axial direction of the plunger.

6. The clutch device according to claim 1 , wherein a formed width of the plunger-side contact surface in an advanceable and retractable direction of the plunger is set larger than a formed width of the washer-side contact surface in a clutch radial direction.

7. The clutch device according to claim 6 , wherein the washer-side contact surface is formed as an arcuate streak extending along a circumferential direction of the washer member, and the plunger-side contact surface is formed as a straight-line shaped streak orthogonal to an axial direction of the plunger.

8. The clutch device according to claim 1 , wherein the washer-side contact surface is formed as an arcuate streak extending along a circumferential direction of the washer member, and the plunger-side contact surface is formed as a straight-line shaped streak orthogonal to an axial direction of the plunger.

Assignees

• Honda Motor Co Ltd

Inventors

• Miyazaki Jun
• Sakuyama Hisashi
• Senmyo Hideo
• Tokito Akira

Classifications

• F16D2013/565

  with means for releasing the clutch pressure in case of back torque · CPC title

• F16D43/216

  with multiple lamellae · CPC title

• F16D43/22

  controlled by both speed and torque · CPC title

• F16D13/56 Primary

  in which the clutching pressure is produced by springs only · CPC title

• F16D43/18

  with friction clutching members · CPC title