| 摘要 |
PCT No. PCT/DE89/00491 Sec. 371 Date Apr. 23, 1991 Sec. 102(e) Date Apr. 23, 1991 PCT Filed Jul. 28, 1989 PCT Pub. No. WO90/01614 PCT Pub. Date Feb. 22, 1990.An actuator assembly for an electromagnetically-actuated, spring-loaded positioning system in displacement engines, such as for lifting valves in internal combustion engines. The positioning mechanism comprises a three-spring system and two electrically-operated, opposed actuating solenoids, by means of which the actuator may be moved therebetween, and held at, two discreet, mutually-opposite operating positions. The actuator assembly further comprises an anchor plate having integrally attached upper and lower stems, wherein the lower stem engages the upper flanged end of a valve stem and, upon reciprocation of the anchor plate, transfers movement to the valve stem which moves the valve from a closed to an open position, or vice-versa. The actuator assembly is symmetrically biased by upper and lower halves of the three-spring system. The upper spring system includes a first spring disposed to engage the upper stem and stressed to force the actuator assembly to the open position of the valve head. The lower spring system comprises: A second spring disposed to engage the lower stem and stressed to move the actuator assembly to the closed position of the valve head; and A third spring disposed to engage a stamp flange on the upper end of the valve stem which spring is stressed to assist the second spring in moving the actuator assembly to the closed position of the valve head. Spring constants of each spring are selected to provide a constant neutral point of the spring system over the service life of the actuator assembly.
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