ELECTROSTATIC CLUTCH

• US 20190319556A1
• Filed: 06/03/2019
• Published: 10/17/2019
• Est. Priority Date: 10/09/2014
• Status: Active Grant

• Current Assignee: Carnegie Mellon University
• Original Assignee: Carnegie Mellon University
• Inventors: Majidi, Carmel, Collins, Steven, Diller, Stuart
• Granted Patent: US 10,749,450 B2
• Time in Patent Office: Days
• CPC Class Codes: F16D 27/00 Magnetically- or electrically- actuated clutches; Control or electric circuits therefor clutches with magnetisable particles F16D37/02; with electro-rheological fluids F16D37/008
• CPC Class Codes: F16D 28/00 Electrically-actuated clutches arrangements for synchronisation F16D23/02; clutches actuated directly by means of an electromagnet F16D27/00; automatic clutches F16D43/00 - F16D45/00; external control F16D48/00
• CPC Class Codes: H02N 13/00 Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect

Abstract

An electrostatic clutch is described comprising a plurality of micron-scale thickness electrodes, adjacent electrodes being separated by a thin film of dielectric material. A power source and controller apply a voltage across two electrodes, causing an electrostatic force to develop. When engaged, a force can be transferred through the clutch. A tensioning device maintains the alignment of the clutch when the electrodes are disengaged, but permits movement in at least one direction. In some embodiments, multiple clutches are connected to an output to provide variable force control and a broad range of torque input and output values. Moreover, the clutch can be used as an energy-recycling actuator that captures mechanical energy from negative work movements, and returns energy during positive work movements.

Claims

1. An electrostatic clutch assembly for transmitting a torque comprising:

a first electrode disposed on the surface of an input shaft,

a second electrode aligned parallel to the surface of the input shaft,

wherein the second electrode is flexible,

wherein at least one of the surface of the first electrode and the surface of the second electrode is coated with a dielectric material, thereby forming a clutch;

a rigid bar connected to the second electrode;

an output connector affixed to the rigid bar; and

a power source for applying an electric field across the first electrode and the second electrode to develop an electrostatic charge, causing the first electrode and the second electrode to exist in either an attractive state or a non-attractive state,

wherein a torque is transmitted through the input shaft to the output connector when in the attractive state.

2. The electrostatic clutch assembly of claim 11 further comprising:

a plurality of clutches arranged concentrically,

wherein each clutch of the plurality of clutches is attached to the input shaft and the output connector.