DUAL DIFFERENTIAL SEMI-ACTIVE ACTUATOR FIT FOR INTERACTION TASKS AND FAST MOTION

• US 20110045932A1
• Filed: 03/26/2009
• Published: 02/24/2011
• Est. Priority Date: 03/27/2008
• Status: Active Grant

• Current Assignee: Maxon Motor AG (Karl-Walter Braun, PhD)
• Original Assignee: Societe de Commercialisation de Produits de La Recherche Appliquee-Socpra-Sciences et Genie SEC
• Inventors: Michaud, François, Fauteux, Philippe, Legault, Marc-Antoine, Lavoie, Marc-André, Lauria, Michel
• Granted Patent: US 8,622,864 B2
• Time in Patent Office: Days
• US Class Current: 475/221
• CPC Class Codes: B25J 9/102 Gears specially adapted therefor, e.g. reduction gears gearings in general F16H
• CPC Class Codes: F16D 2121/28 using electrostrictive or magnetostrictive elements, e.g. piezoelectric elements
• CPC Class Codes: F16H 3/721 with an energy dissipating device, e.g. regulating brake or fluid throttle, in order to vary speed continuously

Abstract

The present invention relates a mechanical differential actuator for interacting with a mechanical load. The mechanical differential actuator comprises first and second semi-active sub-actuators, a velocity source and first and second mechanical differentials having three interaction ports each. The first mechanical differential includes a first interaction port coupled to the velocity source, a second interaction port and a third interaction port coupled to the first semi-active sub-actuator. The second mechanical differential includes a first interaction port coupled to the velocity source, a second interaction port and a third interaction port coupled to the second semi-active sub-actuator. Finally, the second interaction ports of the first and second mechanical differentials are coupled together to form an output which is configured so as to be coupled to the load.

Claims

1. A mechanical differential actuator for interacting with a mechanical load, comprising:

a first semi-active sub-actuator;

a second semi-active sub-actuator;

a velocity source;

a first mechanical differential having three interaction ports, including a first interaction port coupled to the velocity source, a second interaction port and a third interaction port coupled to the first semi-active sub-actuator; and

a second mechanical differential having three interaction ports, including a first interaction port coupled to the velocity source, a second interaction port and a third interaction port coupled to the second semi-active sub-actuator;

wherein the second interaction port of the first mechanical differential and the second interaction port of the second mechanical differential are coupled together to form an output which is configured so as to be coupled to the load.

2. A mechanical differential actuator as recited in claim 1, wherein the velocity source is selected from a group consisting of a powered geared electromagnetic motor, a direct-drive electromagnetic motor, a piezoelectric motor, a hydraulic motor, a hydraulic actuator, a pneumatic motor, a pneumatic actuator, a combustion engine and a turbine.

3. A mechanical differential actuator as recited in claim 1, wherein the first and second semi-active sub-actuator are identical.

4. A mechanical differential actuator as recited in claim 1, wherein the first and second semi-active sub-actuator are selected from a group consisting of a electrorheologic fluid brake, a magnetorheological fluid brake, a dry friction brake, a magnetic particles brake, a hysteresis brake and a hydraulic rotary brake.

5. A mechanical differential actuator as recited in claim 4, wherein the first and second semi-active sub-actuator are magnetorheological fluid brakes.

6. A mechanical differential actuator as recited in claim 5, further comprising a controller for controlling the velocity source and the first and second semi-active sub-actuators by modulating the electrical energy supplied to the magnetorheological fluid brakes.

7. A mechanical differential actuator as recited in claim 6, further comprising a motion sensor for sensing the motion of the output and provide motion information to the controller.

8. A mechanical differential actuator as recited in claim 7, wherein the controller uses a control scheme selected from a group consisting of an electrical tension feed-forward torque control scheme and an electrical current feed-forward torque control scheme.

9. A mechanical differential actuator as recited in claim 6, further comprising a sensor selected from a group consisting of a force sensor and a torque sensor for sensing the force or the torque applied to the load and provide force or torque information to the controller.

10. A mechanical differential actuator as recited in claim 9, wherein the controller uses a torque feedback control scheme.

11. A mechanical differential actuator as recited in claim 1, wherein the first interaction port of the first mechanical differential is coupled to the velocity source so as to move in a first direction and the first interaction port of the second mechanical differential is coupled to the velocity source so as to move in a second direction opposite the first direction.

12. A mechanical differential actuator as recited in claim 11, wherein the ports of the first and second mechanical differentials have corresponding functions.

13. A mechanical differential actuator as recited in claim 1, wherein the first interaction port of the first differential actuator is further coupled to the first interaction port of the second differential actuator so as to move in a common direction.

14. A mechanical differential actuator as recited in claim 13, wherein the first ports of the first and second mechanical differentials have corresponding functions and the second and third ports of the first and second mechanical differentials have alternate functions.

15. A mechanical differential actuator as recited in claim 13, wherein the second interaction port of the first mechanical differential and the second interaction port of the second mechanical differential are coupled together through an external mechanism so that the braking torques of the first and second semi-active sub-actuators produce output torques which are opposed in direction.

16. A mechanical differential actuator as recited in claim 1, wherein the first and second mechanical differentials include respective first and second speed reducer mechanisms for implementing a mechanical differential function, the velocity source being coupled to the first and second speed reducer mechanisms.

17. A mechanical differential actuator as recited in claim 16, wherein the first and second speed reducer mechanisms are selected from a group consisting of a cable mechanism, a lead or ball screw with corresponding nut mechanism, a bar mechanism, a cycloidal gearbox, an epicyclic gearbox, a standard gearbox and a harmonic drive.

18. A mechanical differential actuator as recited in claim 1, wherein the first and second mechanical differentials include respective first and second harmonic gearing stages;

the first harmonic gearing stage comprising a wave generator connected to the first port of the first mechanical differential, a circular spline connected to the second port of the first mechanical differential and a flexible spline connected to the third port of the first mechanical differential;

the second harmonic gearing stage comprising a wave generator connected to the first port of the second mechanical differential, a circular spline connected to the second port of the second mechanical differential and a flexible spline connected to the third port of the second mechanical differential.

19. A mechanical differential actuator as recited in claim 18, wherein the first harmonic gearing stage further comprises a dynamic spline connected to the third port of the first mechanical differential and the second harmonic gearing stage further comprises a dynamic spline connected to the third port of the second mechanical differential.

20. A mechanical differential actuator as recited in claim 1, wherein the first and second mechanical differentials include respective first and second epicyclic gearing stages;

the first epicyclic gearing stage comprising a sun gear connected to the first port of the first mechanical differential, at least one planet gear connected to the second port of the first mechanical differential and an annulus gear connected to the third port of the first mechanical differential;

the second epicyclic gearing stage comprising a sun gear connected to the first port of the second mechanical differential, at least one planet gear connected to the second port of the second mechanical differential and an annulus gear connected to the third port of the second mechanical differential.