Actuator device and method of converting rotational input to axial output with rotary flexure mechanism

Patent metadata

Field	Value
Publication number	US-9787157-B2
Application number	US-201414445898-A
Country	US
Kind code	B2
Filing date	Jul 29, 2014
Priority date	Jul 29, 2014
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

An actuator device includes a motor and a reduction device operatively coupled to the motor and oriented about a central axis, the reduction device configured to modify an input angle of rotation provided by the motor to an output angle of rotation. Further included is a rotary flexure mechanism that includes a rotary flexure operatively coupled to an output portion of the reduction device. The rotary flexure mechanism also includes a plurality of flexure blades coupled to the rotary flexure, each of the flexure blades angularly oriented from the central axis. The rotary flexure mechanism further includes a diaphragm flexure pair operatively coupled to the flexure blades, wherein the diaphragm flexure comprises a rotational and in-plane stiffness greater than an axial stiffness resulting in the rotary flexure mechanism being configured to convert a rotational input to an axial translation.

First claim

The invention claimed is:

1. An actuator device comprising:
a motor;
a reduction device operatively coupled to the motor and oriented about a central axis, the reduction device configured to modify an input angle of rotation provided by the motor to an output angle of rotation; and
a rotary flexure mechanism comprising:
a rotary flexure operatively coupled to an output portion of the reduction device;
a plurality of flexure blades coupled to the rotary flexure, each of the plurality of flexure blades angularly oriented from the central axis;
a diaphragm flexure pair operatively coupled to the plurality of flexure blades, wherein the diaphragm flexure pair comprises a rotational and in-plane stiffness greater than an axial stiffness, the diaphragm flexure pair configured to convert a rotational input to an axial translation, wherein the plurality of blades is operatively coupled to an output plate that is mechanically fastened to the diaphragm flexure pair; and
a diaphragm connector extending between, and operatively coupled to the output plate and the diaphragm flexure pair.

2. The actuator device of claim 1 , wherein the rotary flexure comprises an axial stiffness greater than a rotational stiffness.

3. The actuator device of claim 2 , wherein the axial stiffness of the rotary flexure is greater than about 140,000 lb/in and the rotational stiffness of the rotary flexure is less than about 5 lb*in/degree.

4. The actuator device of claim 1 , wherein the reduction device comprises a first harmonic drive and a second harmonic drive.

5. The actuator device of claim 4 , wherein the first harmonic drive comprises a reduction ratio ranging from about 50:1 to about 100:1 and the second harmonic drive comprises a reduction ratio ranging from about 50:1 to about 100:1.

6. The actuator device of claim 1 , wherein the rotary flexure comprises at least one stop configured to limit rotational movement of the rotary flexure.

7. The actuator device of claim 1 , wherein the diaphragm flexure pair is configured to move in a first axial direction upon rotation of the rotary flexure in a first rotational direction and the diaphragm flexure pair is configured to move in a second axial direction upon rotation of the rotary flexure in a second rotational direction.

8. The actuator device of claim 1 , wherein the motor comprises a stepper motor.

9. The actuator device of claim 1 , wherein the actuator device is disposed in an optical telescope and the diaphragm flexure pair is operatively coupled to a mirror of the optical telescope to control axial movement of the mirror.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Booker Jesse W

Classifications

• G02B7/1827

  Motorised alignment · CPC title

• F16H49/001

  Wave gearings, e.g. harmonic drive transmissions · CPC title

• H02K7/116

  with gears · CPC title

• G02B7/183

  specially adapted for very large mirrors, e.g. for astronomy, {or solar concentrators} · CPC title

• H02K37/24

  Structural association with auxiliary mechanical devices · CPC title