公开(公告)号：US3771541A

公开(公告)日：1973-11-13

申请号：US3771541D

申请日：1971-04-30

Applicant: BENDIX CORP

Inventor： ABBOTT R

IPC: F15B5/00 ,  F15B9/07 ,  G05D16/00

CPC classification number: F15B5/003 ,  F15B9/07 ,  Y10T137/2409 ,  Y10T137/2663

Abstract: An electrohydraulic servo valve design is described having a pair of parallel-directed nozzles connected through conduits to a source of operating fluid under pressure with a load piston connected to the conduits such that its ends communicate with the pressure immediately upstream of the nozzles. A torque motor operates a flapper valve to restrict one nozzle and reduce the restriction of the other to vary the conduit pressure to create a control pressure differential across the load piston. Connected between each of the conduits and the fluid pressure source is a pair of orifices with a reed valve positioned therebetween and supported such that it responds to the control pressure differential to further restrict one of the pair of orifices while reducing the restriction of the other. In this manner, pressure in one conduit having the higher pressure is communicated to the reed valve which moves away from its corresponding orifice to permit the pressure in that one conduit to increase to a value even closer to the supply pressure than before. At the same time the pressure in the other conduit which was reduced is further reduced as the reed valve further restricts the area of its corresponding orifice. Thus, for a servo valve of a given size, the described pair of orifices and adjacent reed valve operate to substantially increase the pressure differential across the load for a given displacement of the flapper valve near null position.

Abstract translation: 描述了一种电动液压伺服阀设计，其具有通过导管连接到压力下的工作流体源的一对平行定向喷嘴，其中负载活塞连接到导管，使得其端部与紧邻喷嘴上游的压力连通。 扭矩马达操作挡板阀以限制一个喷嘴并且减小另一个喷嘴的限制，以改变导管压力以在负载活塞上产生控制压力差。 连接在每个导管和流体压力源之间的是一对孔，其间设置有簧片阀，并且被支撑，使得其响应于控制压力差，以进一步限制该对孔中的一个，同时减少另一个的限制。 以这种方式，具有较高压力的一个导管中的压力被传递到离开其对应孔口的簧片阀，以允许该导管中的压力增加到比以前更接近供给压力的值。 同时，当簧片阀进一步限制其对应孔口的面积时，另一个导管中被压下的压力进一步降低。 因此，对于给定尺寸的伺服阀，所描述的一对孔口和相邻的簧片阀操作以基本上增加在靠近零位置的挡板阀的给定位移的负载上的压力差。