GB1453978A - Linear stepper motor - Google Patents

Abstract

1453978 Piezoelectric motors DEFENCE SECRETARY OF STATE FOR 15 March 1974 [15 March 1973] 12650/73 Heading H2A In a linear stepping motor arrangement, a piezoelectric tube 1 containing fluid, e.g. silicone oil 14, is sealed at one end by a rigid wall 7 joined to a body 2 which may be magnetically clamped to a bed 4, and is sealed at the other end by a flexible diaphragm 9 joined to a further clamping body 3, and when a voltage is applied to two electrodes 5, 6, via two leads 17, 16 with body 2 clamped and body 3 unclamped, the length and diameter of tube 1 are caused to vary, the volume inside tube 1 is changed and as a consequence the diaphragm 9 and body 3 execute a step movement. Body 3 may then be clamped and body 2 undamped so that on switching off the voltage the tube relaxes to its former length and so causes a step movement at the other end of the tube. A rod 10 assists in the alignment of the system. In a modification (not illustrated) a third magnetic clamp is incorporated. In the embodiment of Fig. 3 (not shown), movement of a diaphragm (29) causes a contacting ball (34) and rod (33) to produce movement of the corresponding clamping body (3). In the embodiments of Figs. 4, 5 (not shown), rods (48, 56) are mounted for motion relative to flexible ring seals (46, 47, 54, 55).