Piezo-electric motor with piezo stack and spring strap

A piezo-electric motor comprising:

• a piezo stack movable along an actuation axis in response to an application of a voltage;
• a strip including a pair of opposed actuation surfaces, the strip fixedly attached to the piezo stack such that the strip moves between a retracted position and an extended position in response to movement of the piezo stack;
• a spring strap extending around a portion of the piezo stack and the strip and operable to bias the strip toward the retracted position;
• a pair of pads, each pad engageable with one of the actuation surfaces;
• and
• a spring head engageable with each pad of the pair of pads and operable to bias each pad of the pair of pads into frictional engagement with the respective actuation surface such that each pad of the pair of pads sticks to the respective actuation surface as the actuation surface moves toward one of the retracted position and the extended position and slips on the actuation surface as the actuation surface moves toward the other of the retracted position and the extended position.

A piezo-electric motor comprising:

• a piezo stack operable in response to an application of a voltage to move along an actuation axis;
• a strip support fixedly attached to the piezo stack;
• a strip including a pair of actuation surfaces fixedly attached to the strip support, the actuation surfaces movable between a retracted position and an extended position in response to movement of the piezo stack;
• a spring strap at least partially surrounding the piezo stack, the strip support, and the strip and operable to bias the strip toward the retracted position, the spring strap cooperating with the strip support to define a wall that surrounds the perimeter of each of the actuation surfaces and extends beyond each of the actuation surfaces in a direction normal to the actuation axis;
• a pair of pads, each pad engageable with one of the actuation surfaces;
• and
• a spring head engageable with each pad of the pair of pads and operable to bias each pad of the pair of pads into frictional engagement with the respective actuation surface such that each pad of the pair of pads sticks to the respective actuation surface as the actuation surface moves toward one of the retracted position and the extended position and slips on the actuation surface as the actuation surface moves toward the other of the retracted position and the extended position.

A piezo-electric motor comprising:

• an actuation portion including an actuation surface and a piezo stack that is operable in response to an application of a voltage to move the actuation surface along an actuation axis between a retracted position and an extended position;
• a spring strap partially surrounding the actuation portion and operable to bias the actuation surface toward the retracted position;
• a movable portion frictionally engaged with the actuation surface, wherein the voltage is selected such that the movable portion sticks to the actuation surface as the actuation surface moves toward one of the retracted position and the extended position and slips on the actuation surface as the actuation surface moves toward the other of the retracted position and the extended position;
• and
• a first solder pad coupled to a first side of the piezo stack and a second solder pad coupled to a second, opposite side of the piezo stack, wherein the first solder pad and the second solder pad are each configured to be coupled to an electrical lead to provide power to the piezo stack.