Piezo motors technologies
Piezomotors are linear or rotary motors offering high precision and blocking at rest. These properties make them suitable for long stroke micro positioning applications.
CEDRAT Group's has experimented different kinds of piezoelectric motors either by retrofitting / testing standard piezomotors or by developing new original concepts, in the context of space applications or fine instrumentation projects:
- Inchworm piezo motors : These motors are based on steps produced by the quasi-static motion of a piezo stator to drive a second member. They offer a good controllability but are slow (<10mm/s) and expensive as multi-phases. CEDRAT has experimented such motors with some first versions of its LPM Linear Piezo Motor (in a CNES French space agency project) or with the RPMHPP Rotating Piezo Motor (in ESA Eu Space Agency project).
- Ultrasonic motors (USM) : These motors are based on an ultrasonic vibration (generally elliptic and using resonance) of the stator to drive a second member (as a rotor). They are fast (> 100mm/s), offer a medium controllability and are sensitive to variations of loads and environment. Their electronics can be complex to track resonance. From Cedrat, the LPM20-3 space qualified Linear Piezo Motor is a multi-mode ultrasonic motor (MMUM). It is vacuum compatible and space qualified thanks to CNES and EADS projects. Rotating piezo electric motors, such as the RPA for ESA, and rotating magnetostrictive motors have also been developed by CEDRAT using this concept to offer a large torque at low speed. CEDRAT has also retrofitted Travelling Wave Ultrasonic Motors (TWUM) from Shinsei to make them space compatible. CEDRAT has also experimented the Squiggle® piezo motors for Newscale which are suited to tiny locking or positioning mechanisms.
- Inertial Stepping Motors (ISM) : These motors also called (Smooth) Impact Drive Mechanisms (IDM or SIDM) are based on steps performed by the transient motion of a piezo stator driving a second member. They offer medium speeds (10-50mm/s). These motors need only one piezo ceramic and one electronic channel, leading to a good miniaturization potential. CEDRAT has developed the SPA Stepping Piezo Actuator, a new piezo based on the ISM concept and benefiting of the APA Amplified Piezoelectric Actuator heritage.
Following examples show various prototypes and customised products.
To know more about our piezo motors see also our related publications on rotating piezo motors or on our related publications linear piezo motors.
| Stepping Piezo Actuators: SPA |
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| Description: | Stepping Piezo Actuators (SPAs) are new long-stroke linear piezoelectric motors for micro/nano positioning applications. The load can be fixed firmly to the shaft. Non magnetic or cryogenic versions upon request. |
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| Applications: | Nano positioning, Locking, Refocusing, Piezo Valves, Micro Robots ... | |
| Status: | Prototype | |
| Rotary Piezo Actuator: RPA |
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| Description: | RPA is a Resonant Rotary Piezoelectric Motor that displays the advantages of a piezo motor |
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| Applications: | Aerospace, High positioning accuracy... | |
| Status: | Space evaluated | |
