Electrostatic clutch and transmissions
Methods and apparatus related to electrolaminate clutches and transmissions are disclosed. A device can include: an input shaft that can be coupled to an electrolaminate sheet; an output shaft that can be coupled rigidly to a spring positioned over the input shaft, where the spring includes a tab that fits a groove of a spring capture ring that can be positioned over the input shaft; and a drum connected to an electrical ground between the electrolaminate sheet and the spring capture ring, where the drum can be coupled rigidly to the spring capture ring. Then, when a voltage is applied to the electrolaminate sheet, the electrolaminate sheet can clamp to the drum and impart rotation of the input shaft to the drum. The imparted rotation can cause the spring capture ring and the spring to rotate and clamp down on the input shaft, imparting rotation to the output shaft.
1. A device for controlling transmission of torque, comprising:
a first stage;
a second stage;
an electrolaminate clutch comprising a first portion and a second portion, wherein the first portion of the electrolaminate clutch is coupled to the first stage, and wherein the second portion of the electrolaminate clutch is loosely coupled to the second stage via a support member that can move relative to the second stage within a certain range such that the first and second portions of the electrolaminate clutch can align together; and
an electrical circuit electrically connected to the first and second portions of the electrolaminate clutch, wherein (i) when the electrical circuit applies a voltage between the two portions, the two portions are electrostatically clamped together such that torque is transmitted between the first and second stages and (ii) when the electrical circuit does not apply the voltage, torque is not transmitted between the first and second stages.
2. The device of claim 1 , wherein the voltage applied by the electrical circuit brings the second portion of the electrolaminate clutch into alignment with the first portion of the electrolaminate clutch.
3. The device of claim 1 , wherein the first stage is an input stage and the second stage is an output stage.
4. The device of claim 3 , wherein the input stage comprises a motor.
5. The device of claim 3 , wherein the output stage comprises a gearbox.
6. The device of claim 1 , wherein the support member is coupled to the second stage via at least one pin that fits into an oversized hole in the support member.
7. The device of claim 1 , wherein the support member comprises a larger disc and a smaller disc arranged concentrically together, wherein the second portion of the electrolaminate clutch is rigidly coupled to the smaller disc.
8. The device of claim 7 , wherein the second portion of the electrolaminate clutch is flexible and is wider than the smaller disc.
9. The device of claim 1 , wherein at least one of the first and second portions of the electrolaminate clutch is flexible.
10. The device of claim 1 , wherein at least one of the first and second portions of the electrolaminate clutch has a thickness of 0.09 inches or less.
11. The device of claim 1 , wherein each of the first and second portions of the electrolaminate clutch is flexible and comprises a respective substrate, a respective conductive layer, and a respective dielectric layer, with the respective dielectric layers of the two portions facing each other.
12. The device of claim 1 , wherein the first portion of the electrolaminate clutch is rigid and comprises a metal surface, and wherein the second portion of the electrolaminate clutch comprises a substrate, a conductive layer disposed on the substrate, and a dielectric layer disposed on the conductive layer with the dielectric layer facing the first portion of the electrolaminate clutch.
13. The device of claim 1 , wherein the first portion of the electrolaminate clutch comprises a first disk and the second portion of the electrolaminate clutch comprises a second disk.
14. The device of claim 1 , wherein the first portion of the electrolaminate clutch comprises a first drum and the second portion of the electrolaminate clutch comprises a second drum.
15. A method, comprising:
controlling transmission of torque between a first stage and a second stage using an electrolaminate clutch comprising a first portion and a second portion, wherein the first portion is coupled to the first stage and the second portion is loosely coupled to the second stage via a support member that can move relative to the second stage within a certain range such that the first and second portions of the electrolaminate clutch can align together, wherein the controlling comprises:
when a voltage is applied between the two portions of the electrolaminate clutch, the two portions are electrostatically clamped together such that torque is transmitted between the first and second stages; and
when the voltage is not applied, torque is not transmitted between the first and second stages.
16. The method of claim 15 , wherein the voltage is applied by an electrical circuit electrically connected to the first and second portions of the electrolaminate clutch.
17. The method of claim 15 , wherein the voltage brings the second portion of the electrolaminate clutch into alignment with the first portion of the electrolaminate clutch.
18. The method of claim 17 , wherein the voltage brings the second portion of the electrolaminate clutch into alignment with the first portion of the electrolaminate clutch by causing the support member to move relative to the second stage.
19. The method of claim 15 , wherein at least the second portion of the electrolaminate clutch is flexible, wherein the voltage causes the second portion of the electrolaminate clutch to conform to a shape of the first portion of the electrolaminate clutch.