Piezoelectric voltage source

摘要

940,112. Piezo-electric generators. CLEVITE CORPORATION. Sept. 18, 1962 [Nov. 6, 1961], No. 35465/62. Heading H2A. A piezo-electric spark generator, e.g. for I.C. engines, consists of a ball or roller bearing, one race of which is distorted out of round so that on rotation, pressure is periodically applied at each revolution to the piezo-electric element. As shown in Fig. 1 the piezo-electric elements 13a, 13b, 13c, 13d are mounted in the inner race 3 of a bearing whose outer race 5 is supported in a carrier 9 of somewhat larger diameter and is distorted by an adjustable screw 11. Alternate piezo-electric elements are oppositely polarised, and since in operation they are oppositely stressed (i.e. in the position shown in Fig. 1, 13a and 13b are compressed and 13b and 13d are stretched) they feed a like voltage in parallel to the output terminal 22 and lead 25. Either inner or outer race may be rotated, or both may rotate in opposite directions. In a modification (Figs. 3 and 4, not shown) only two, oppositely disposed, elements are used. Alternatively (Fig. 5, not shown) the pressure from the distorted race is transmitted through radial plungers to a central rubber body, which in turn presses on an axially disposed piezoelectric element. As shown in Fig. 7, the inner race 3c1 is distorted, this distortion being transmitted through rollers 7a1 and outer race 5c1 to a plunger 901 acting on a laterally disposed element, not shown.