| 摘要 |
A hydraulically driven diaphragm pumping machine comprises a plunger (6) that is slidably mounted in a middle part of the inside of the machine's hydraulic cylinder (5) between first and second bellow-like diaphragms (4,10). Ends of the plunger (6) are connected to the first and second bellows-like diaphragm (10) to define respective first and second outer annular spaces (a) that are independent of one another, and the pressure of fluid in the first annular space (a) is independent of the pressure of fluid in the second annular space (a). The machine may also comprise a hydromechanical switch for commutating a valve (102) to automatically control the supply of hydraulic fluid to the hydraulic cylinder at given moments of the machine's cycle, comprising: a linkage (108,109) for converting linear motion of a piston (106) into rotary motion; a cam (103) rotatably driven by the linkage (108,109); and a spring (115) that is compressed to store energy by rotation of the cam (103) during a stroke of the piston (106), and arranged to release its stored energy to commute said valve (102) when the piston (106) is at given positions along the hydraulic cylinder (107). This commutation device also relates to any hydraulic cyclical working machine having a linear moving operating part and requiring to be automatically controlled via openings commutation in order to achieve desired working cycle parameters e.g. pressure values, cycle phases duration, etc. |
