| 摘要 |
790,626. Fluid-pressure servomotor-control systems. KEELAVITE CO., Ltd. Nov. 11, 1955 [Sept. 6, 1954], No. 25850/54. Class 135. An hydraulic motor A, Fig. 1, which is supplied with pressure liquid by a pump A<1>, is set for a given speed by either adjusting the constant-speed motor driving the pump or the pump capacity whilst metering pumps F<1> and H<1>, chain-driven from the motor A and a second motor B, respectively, and arranged in series so that the output of one just meets the input requirement of the other when the motors have the required speed relationship. The motor B is supplied with pressure liquid by a pump B<1> also driven by a constant speed motor; the capacity of the pump B is such as to enable the motor B to be driven at the required speed in relation to the motor A and to provide surplus liquid which escapes through a valve D to the reservoir C<1>. Any reduction in set speed of the motor B and hence pump H<1> brings about a pressure increase in the valve actuating chamber E<2> which causes the valve D to close and hence effects an increase in the speed of the motor B since pump H<1> is connected by a line G to pump F<1> and a line G<1> to the chamber E<2>; an increase in the speed of the motor B above that set causes valve E<2> to open and reduce the speed of the motor B. The range of speed relationship between the motors A and B and the sensitivity of each range can be varied by adjusting the relative capacities of the metering pumps F<1> and H<1>. The phase relationship between the motors A and B can be altered during operation of the apparatus by actuating a manual pump F4 to inject into or withdraw from the line G an appropriate quantity of liquid. An adjustable escape orifice G<2> may be provided in the line G as an alternative or additional means of varying the speed relationship between the motors. In a modification, the pump K, Fig. 2, supplies liquid to series-connected motors N and P, the capacity of the motor N being greater than that of the motor P whilst across the metering pump Q is a cylinder containing an adjustable spring-loaded piston T<1>, the adjustment of which forces liquid into or withdraws it from the line S connecting the pump Q to the other metering pump R to bring about a change in phase between the motors N and P. The valve D is arranged and operated as in Fig. 1. The pump F4, Fig. 1, and piston T<1> may be automatically operated and the pump F<4> may be of the variable capacity type. The valve closure part E and the pressure responsive part E<1> of the valve D need not be a unitary structure as shown. Specification 711,486 is referred to. |
