GB1128868A - Electro-hydraulic actuator mechanism - Google Patents

Abstract

1,128,868. Valves. ITT INDUSTRIES Inc. 22 March, 1967 [30 March, 1966], No. 13463/67. Heading F2V. [Also in Division F1] An electro-hydraulic actuator especially for operating valves has an actuator piston 90 slidable in a cylinder 36 formed in the central portion of a main casting 16 having a cavity to one side of the cylinder which is closed by a housing 22 to form a reservoir for hydraulic fluid supplied to the cylinder 36 by a pump 58 driven by an electric motor 56, the motor and pump being mounted in the reservoir. The pump 58 has a cylinder 62 screwed into a socket 60 integral with the housing 22 and a piston 64 reciprocated in the cylinder 62 by an eccentric 66 driven by the motor 56. The output of the pump is adjustable from outside the housing 22 by rotation of a shaft (86), Figs. 4 and 5 (not shown), having a pinion (84) meshing with a gear (82) provided on the cylinder 62 which is thus axially adjusted. Fluid enters the cylinder 62 through a side wall port 70 and is discharged past an outlet valve 72 and through passages 74, 76, 101, 104 in the housing 22, main casting 16 and a cylinder end cover 18 into the top of the cylinder 36. The housing 22 may be inverted, Fig. 8 (not shown), whereby fluid is pumped to the bottom of the cylinder 36 through a passage 106 to cause upward movement instead of downward movement of the piston 90 against a spring 94 for the return stroke. A lever 134 pivoted by a cross-pin 136 of the piston-rod 92 may be connected by external linkage to e.g. a further valve. Projections 146 on the piston-rod 92 may operate switches 138. To perform the return stroke an electrically operated by-pass valve 80 is opened with the pump stopped. The piston may be held in mid-stroke by leaving the pump running and partially opening the bypass valve.