Electroactive polymer actuated motors

• US 7,750,532 B2
• Filed: 02/24/2006
• Issued: 07/06/2010
• Est. Priority Date: 03/21/2005
• Status: Active Grant

• Current Assignee: Bayer Materialscience AG (Covestro AG)
• Original Assignee: Artificial Muscle, Inc. (Covestro AG)
• Inventors: Heim, Jonathan R.
• Primary Examiner(s): Benson; Walter
• Assistant Examiner(s): Gordon; Bryan P
• Application Number:
  US11/361,683
• Publication Number:
  US 20070200453A1
• Time in Patent Office: 1,593 Days
• Field of Search: 310/800, 310/324, 310/328, 74/103.9, 748/42, 74/29
• US Class Current: 310/311
• CPC Class Codes: H02N 2/046 for conversion into rotary motion
• CPC Class Codes: H10N 30/206 using only longitudinal or thickness displacement, e.g. d33 or d31 type devices
• CPC Class Codes: Y10S 310/80 Piezoelectric polymers, e.g. PVDF
• CPC Class Codes: Y10T 74/177 Rack and pinion adjusting means
• CPC Class Codes: Y10T 74/18088 Rack and pinion type

Abstract

Devices employing electroactive polymer actuators are disclosed. Acrylic dielectric material based actuators are optionally provided in which architectures are presented that allow for improved power output as compared with other known acrylic dielectric material based transducers. Such technology may be applied in motor-driven applications, lightweight flight applications and lighting applications among others.

Claims

1. A drive system comprising:

a rack and pinion drive interface, the pinion supported by a one-way clutch, an output shaft driven by the clutch, and a transducer comprising an electroactive polymer stretched into a concave or convex shape where at least a portion of the electroactive polymer is stretched in a perpendicular direction relative to a remainder of the electroactive portion to form the concave or convex shape, wherein the rack is positioned to be driven by said transducer in a reciprocal motion between engagement in a state where the rack and pinion mesh and disengagement in another state where the rack and the pinion do not mesh.

2. The drive system of claim 1, wherein the transducer comprises a frustum configuration and the rack is attached to a central, substantially rigid body portion of the transducer.

3. The drive system of claim 1, further comprising another rack and pinion and another clutch, wherein the output shaft is driven in opposite directions by each clutch.

4. The drive system of claim 3, further comprising two electroactive polymer transducers, each positioned to drive one rack.

5. The system of claim 1, wherein the output shaft comprises a threaded valve stem and the system further comprises a valve body, the valve stem being manually adjustable when the rack and pinion are not engaged.

6. A motor comprising:

at least one drive assembly comprising an electroactive polymer actuator set within a frame of an actuator, wherein the electroactive polymer actuator comprises an electroactive polymer stretched into a concave or convex shape where at least a portion of the electroactive polymer is stretched in a perpendicular direction relative to a remainder of the electroactive portion to form the concave or convex shape,

a rack and pinion assembly, the rack in operative communication with the actuator and the pinion in operative communication with a clutch, and

a shaft in operative communication with the clutch and rotationally mounted across a walled frame stacked upon the actuator frame.

7. The motor of claim 6, wherein the clutch is a roller-clutch set upon the shaft.

8. The motor of claim 6, comprising two drive assemblies, one for actuation in a clockwise direction and one for actuation in a counter-clockwise direction.

9. The motor of claim 6, wherein the actuator comprises a frustum configuration.

10. The motor of claim 6, wherein the actuator is acrylic elastomer based and adapted to cycle at between about 50 and about 200 Hz.

12. The motor of claim 6, comprising two rack and pinion assemblies, both for actuating a single shaft in one rotational direction during oppositely-directed phases of drive assembly motion.

13. The motor of claim 12, comprising two drive assemblies mounted across from one other upon the walled frame.

11. A motor comprising:

at least one drive assembly comprising an electroactive polymer actuator having an axis of actuation, wherein the electroactive polymer actuator comprises an electroactive polymer stretched into a concave or convex shape where at least a portion of the electroactive polymer is stretched in a perpendicular direction relative to a remainder of the electroactive portion to form the concave or convex shape,

a lead screw assembly in operative cooperation with the actuator; and

at least one clutch adapted to deliver rotational output of the motor in one direction around the axis of drive assembly actuation.

14. The motor of claim 11, wherein the lead screw assembly comprises a lead screw and slider, the slider affixed to the actuator.

15. The motor of claim 11, wherein right-handed arid left-handed pitch lead screw segments are provided to deliver rotational output of the motor in one direction under power during oppositely-directed displacements of at least one drive assembly.

16. A drive system comprising:

a rack and pinion drive interface, the pinion supported by a one-way clutch, an output shaft driven by the clutch, and a transducer comprising an electroactive polymer stretched into a concave or convex shape, wherein the rack is positioned to be driven by said transducer in a reciprocal motion between engagement in a state where the rack and pinion mesh and disengagement in another state where the rack and the pinion do not mesh; and

where the transducer comprises a frustum configuration and the rack is attached to a central, substantially rigid body portion of the transducer.