Clutch actuation using differential pressure

Patent metadata

Field	Value
Publication number	US-10247261-B2
Application number	US-201715443108-A
Country	US
Kind code	B2
Filing date	Feb 27, 2017
Priority date	Mar 1, 2016
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

An actuation device having a piston is used to actuate a mechanical or friction clutch by means of differential pressure. Two sides of a piston are pressurized, and the relative pressure between the two sides is decreased or increased to move the piston in either direction. The position of the piston may be determined using position feedback, or with springs of known spring rates, two piston areas, and knowing the pressures of the two areas. The actuation device may be used with a selectable clutch to actuate an actuation cam, and may also have application with other clutches requiring the ability to achieve multiple positions and clutch modes.

First claim

What is claimed is:

1. An actuator device for a selectable clutch having a plurality of mode positions for controlling relative rotation between two components connected by the selectable clutch, the actuator device comprising:
a piston housing having an exterior surface, a piston housing longitudinal bore extending longitudinally there through, a first fluid passage extending inwardly from the exterior surface and intersecting the piston housing longitudinal bore proximate a first bore end, and a second fluid passage extending inwardly from the exterior surface and intersecting the piston housing longitudinal bore proximate a second bore end; and
a piston having a piston body disposed within the piston housing longitudinal bore for longitudinal motion therein,
wherein a first pressure force acting on the piston body toward the second bore end is equal to a first pressure supplied at the first fluid passage multiplied by a cross-sectional area of a first side of the piston body,
wherein a second pressure force acting on the piston body toward the first bore end is equal to a second pressure supplied at the second fluid passage multiplied by a cross-sectional area of a second side of the piston body,
wherein the piston housing includes a longitudinal slot extending inwardly from the exterior surface and intersecting the piston housing longitudinal bore, and
wherein the actuator device comprises a cam actuator bar mounted to the piston body and extending through the longitudinal slot so that the cam actuator bar can be operatively connected to an actuator cam of the selectable clutch to move the selectable clutch between the plurality of mode positions as the piston moves longitudinally within the piston housing longitudinal bore.

2. The actuator device according to claim 1 , comprising a first piston spring operatively connected to the piston body, wherein a first spring force of the first piston spring acting on the piston body toward one of the first bore end and the second bore end is equal to a first spring constant for the first piston spring multiplied by a first compression amount of the first piston spring.

3. The actuator device according to claim 2 , wherein the first spring force biases the piston toward the second bore end.

4. The actuator device according to claim 3 , wherein the piston moves toward the second bore end when the first pressure force plus the first spring force is greater than the second pressure force.

5. The actuator device according to claim 3 , wherein the piston moves toward the first bore end when the first pressure force plus the first spring force is less than the second pressure force.

6. The actuator device according to claim 3 , wherein the piston remains stationary when the first pressure force plus the first spring force is equal to the second pressure force.

7. The actuator device according to claim 3 , comprising a second piston spring operatively connected to the piston body and biasing the piston toward the first bore end, wherein a second spring force of the second piston spring acting on the piston body toward the first bore end is equal to a second spring constant for the second piston spring multiplied by a second compression amount of the second piston spring, wherein the piston moves toward the second bore end when the first pressure force plus the first spring force is greater than the second pressure force plus the second spring force, wherein the piston moves toward the first bore end when the first pressure force plus the first spring force is less than the second pressure force plus the second spring force, and wherein the piston remains stationary when the first pressure force plus the first spring force is equal to the second pressure force plus the second spring force.

8. The actuator device according to claim 1 , wherein the piston comprises
a first piston stop extending from the piston body and limiting movement of the piston body toward the first bore end in a longitudinal direction; and
a second piston stop extending from the piston body and limiting movement of the piston body toward the second bore end in the longitudinal direction.

9. A selectable clutch comprising:
an outer race;
an inner race rotatable relative to the outer race;
a selective locking mechanism having a plurality of locking modes for controlling relative rotation between two components connected by the selectable clutch;
an actuator cam that is rotatable between a plurality of mode positions each causing the selective locking mechanism to engage one of the plurality of locking modes; and
the actuator device according to claim 1 operatively connected to the actuator cam to move the selective locking mechanism between the plurality of mode positions as the piston moves longitudinally within the piston housing longitudinal bore.

10. The selectable clutch according to claim 9 , wherein the piston housing comprises a longitudinal slot extending inwardly from the exterior surface and intersection the piston housing longitudinal bore, and wherein the actuator device comprises a cam actuator bar mounted to the piston, extending through the longitudinal slot and operatively connected to the actuator cam to move the actuator cam between the plurality of mode positions.

11. The selectable clutch according to claim 10 , wherein the actuator cam comprises an actuator tab operatively connected to the cam actuator bar.

12. The selectable clutch according to claim 11 , wherein the actuator tab has a radially extending slot receiving the cam actuator bar.

13. The selectable clutch according to claim 9 , wherein the piston housing comprises a longitudinal slot extending inwardly from the exterior surface and intersection the piston housing longitudinal bore, and wherein the actuator cam comprises an actuator tab extending from the actuator cam and through the longitudinal slot and operatively connected to the piston to move the actuator cam between the plurality of mode positions when the piston moves within the piston housing longitudinal bore.

14. The selectable clutch according to claim 13 , wherein the piston comprises an annular groove in the piston body receiving the actuator tab and engaging the actuator tab to move the actuator cam as the piston moves within the piston housing longitudinal bore.

Assignees

• Borgwarner Inc

Inventors

• Campton Calahan B
• Peglowski Brett
• Spangler Christopher A

Classifications

• F16D2125/28

  Cams; Levers with cams · CPC title

• F16D2125/06

  Pistons · CPC title

• F16D2121/04

  acting on a piston-type actuator, e.g. for liquid pressure · CPC title

• F16D41/16

  the action being reversible · CPC title

• F16D41/14

  the effective stroke of the pawl being adjustable · CPC title