Method of and means for rendering a throttle controlled hydraulic system immune or substantially so to irregularities

摘要

386,010. Hydraulic transmission of power. CINCINNATI MILLING MACHINE CO., Cincinnati, Ohio, U.S.A.-(Assignees of Ernst, H. ; 3617, Edwards Road, and Goodrich, C. W. M. ; 6697, Bramble Avenue, both in Cincinnati, Ohio, U.S.A.) June 15, 1931, No. 17317. Convention date, June 16, 1930. [Classes 69 (ii) and 135.] A throttle-controlled hydraulic system is rendered immune from irregularities consequent on variations in viscosity or temperature of the liquid, and/or variations in work resistance, by means of a valve member controlled by the differential pressures created by a fixed resistance and the throttle ; the fixed resistance may be adjustable in value in some cases. In the form shown in Fig. 4, comprising a constant displacement pump 3 and a working cylinder M, a fixed resistance R1 and a throttle R2 are disposed in the supply and outlet sides of the system respectively. A part of the pump output is returned to a reservoir 1 through pipes 19, L, under the control of a valve member V carried by a member X ; the latter has surfaces A1, A2 acted on by the pressures in front of and behind the resistance R1, and surfaces A3, A4 acted on by the pressures due to the throttle R2. In the form shown in Fig. 3, the surfaces A2, A3 are amalgamated and the throttle R2 is in the supply side of the system. In another form, the supply side is connected to an accumulator CP, Fig. 6, and a manually adjustable throttle R2 or a throttle Rx adjustable manually or automatically from the driven member is employed. Other systems employing an accumulator and with parts arranged in a different order are indicated in Figs. 7 and 9. As shown in Fig. 11, several motors each with its own throttle R2 may be supplied through a common main B from one pump, and one resistance R1 may serve for all. In all forms, the constant-discharge pump 3 may be replaced by a variable-discharge pump, which may be set to yield any desired constant output, the setting means being preferably linked to means for varying the fixed resistance R1, as indicated in Fig. 13 ; if desired, a piston 43, Fig. 14, subject to the pressure beyond the fixed resistance may set both the pump and the fixed resistance. Specification 297,104, [Class 69 (ii), Hydraulic presses &c.], is referred to.