Piezo-actuated braking system and method for a stepper motor
View Patent ↗A piezo-actuated braking system for a stepper motor. The braking system has a disk fixed to the output shaft of the stepper motor. Further, the braking system includes a piezo-actuated brake having a clamping structure, including two brake elements positioned in alignment on either side of the disk. The piezo-actuated brake includes a piezoelectric element connected to the clamping structure to move the brake elements together, thus applying a braking force to the disk. Various embodiments of the braking system along with related methods are also described.
1. A piezo-actuated braking system for a stepper motor, the system comprising:
a disk attached to a shaft, the shaft being operatively connected to the output shaft of the stepper motor; and
a piezo-actuated brake having:
a clamping structure, including two brake elements positioned in alignment on either side of the disk; and
a piezoelectric element mechanically connected to the clamping structure to move the brake elements together for applying a braking force to the disk.
2. The system of claim 1 further comprising a home sensor positioned adjacent the disk to detect when the disk is in a home position.
3. The system of claim 2 , wherein the home sensor is an optical home sensor.
4. The system of claim 2 , wherein the disk includes a notch to signify the home location.
5. The system of claim 1 , wherein the disk and the clamping structure are located within the stepper motor.
6. The system of claim 5 , wherein the disk is added below a motor bearing.
7. The system of claim 1 , wherein the piezo-actuated brake further comprises a mechanical amplifier, mechanically coupled to the piezoelectric element, the mechanical amplifier being configured to amplify the motion resulting from the movement of the piezoelectric element.
8. The system of claim 1 , wherein the disk carries braking material.
9. The system of claim 1 , wherein the clamping structure carries braking material.
10. The system of claim 1 , wherein the disk and the clamping structure are located external to the stepper motor.
11. The system of claim 1 , wherein braking force insufficient to hold the motor stationary is used to control dynamic motion of the motor or for diagnostic purposes.
12. A piezo-actuated braking method for a stepper motor, the method comprising:
providing a disk attached to a shaft, the shaft being operatively connected to the output shaft of the stepper motor;
providing a piezo-actuated brake having:
a clamping structure, including two brake elements positioned in alignment on either side of the disk; and
a piezoelectric element mechanically connected to the clamping structure to urge the brake elements together for applying a braking force to the disk;
applying an electrical input to the piezoelectric element causing its movement;
moving the clamping structure through the mechanical movement of the piezoelectric element; and
braking the rotation of the disk through the clamping action of the clamping structure on the disk.
13. The method of claim 12 further comprising a home sensor positioned adjacent the disk, detecting when the disk is in a home position.
14. The method of claim 13 , wherein home sensor is an optical home sensor.
15. The method of claim 13 , wherein the disk includes a notch to signify the home location.
16. The method of claim 12 , wherein the disk and the clamping structure are located within the stepper motor.
17. The method of claim 16 , wherein the disk is added below a stepper motor bearing.
18. The method of claim 12 , wherein the piezo-actuated brake further comprises a mechanical amplifier, mechanically coupled to the piezoelectric element, the mechanical amplifier amplifying the movement of the piezoelectric element.
19. The method of claim 12 , wherein the disk carries braking material.
20. The method of claim 12 , wherein the clamping structure carries braking material.
21. The method of claim 12 , wherein the disk and clamping structure are located external to the stepper motor.
22. The method of claim 12 , wherein braking force insufficient to hold the motor stationary is applied to control dynamic motion of the motor or for diagnostic purposes.
23. A piezo-actuated braking system for a stepper motor, the system comprising:
a disk attached to the output shaft of the stepper motor; and
a piezo-actuated brake having:
a clamping structure, including two brake elements positioned in alignment on either side of the disk; and
a piezoelectric element mechanically connected to the clamping structure to urge the brake elements together for applying a braking force to the disk; and
a mechanical amplifier, mechanically coupled to the piezoelectric element, the mechanical amplifier being configured to amplify the motion resulting from the movement of the piezoelectric element.