Double reciprocation pump

Abstract

Disclosed is a double reciprocation pump wherein a pump operation is always stable, and pulsation is dampened. A pair of spaces are formed in the inside of a case member (2) in the axial direction of the case member (2). Each of movable partition members (3) is disposed so as be deformable in each of the pair of spaces in the axial direction of each space, so that each space is divided into a pump chamber (5) and an operation chamber (6) in the axial direction of each space. Coupling shafts (11) couple the movable partition members (3) via extendable members (14) so that the movable members (3) can extend in the axial direction thereof. Valve mechanisms (27) introduce a working fluid to the operation chambers (6), and discharge the working fluid from the operation chambers (6). A controller (25) switches the valve mechanisms (27) so that a distance of an overlapped portion in which a compression stroke of one pump chamber (5) and a compression stroke of the other pump chamber (5) are partially overlapped to each other, is formed, on the basis of the output of a displacement sensor (23) which continuously detects the displacement of each of the pair of movable partition members (3).

Description

technical field [0001] The present invention relates to a double-connected reciprocating pump. The double-connected reciprocating pump operates by repeating and alternately performing a compression process and an expansion process in a pair of pump chambers. The pair of pump chambers are connected by a connecting shaft. Formed by bellows, diaphragm, plunger and other movable partition parts, the present invention especially relates to a double reciprocating pump in which an elastic member is arranged on the connecting shaft to reduce the pulsation of the conveying fluid. Background technique [0002] There is known a duplex reciprocating pump as follows: a pair of closed spaces are divided into a pump chamber and a working chamber by means of a movable partition member such as a bellows connected by a connecting shaft, and a working fluid is alternately introduced into a pair of working chambers, thereby The connecting shaft is reciprocated to alternately compress and extend...

AI Technical Summary

Problems solved by technology

For example, when applied to semiconductors, there are problems such as: particles clogged in the filter are squeezed out by pulsation and mixed into the downstream side; or particles clogged in the filter leak from the joint due to shaking of the pipe ; or the liquid level of the cleaning tank fluctuates; or the front end of the nozzle used to spray the liquid on the wafer vibrates to reduce the cleaning efficiency; or the inertial resistance of the liquid increases to make the flow unstable

[0006] However, in the case of the double reciprocating pump disclosed in the above-mentioned Patent Document 1, at the end of the stroke of one pump chamber from the expansion process to the compression process, the expansion process of the other pump chamber starts, and the expansion process is performed by the contraction of the coil spring. Compensating for the delay in the start of the expansion process, compared with the method of actively repeating the process of ending and starting the compression process with a pair of pump chambers, there is a problem that the pulsation elimination effect is small

[0007] In addition, for the double reciprocating pump disclosed in Patent Document 2, the timing of switching between the expansion process and the compression process of the pump chamber is controlled by time, so the heat generation of the elastic member and the surrounding environment after the start of operation are controlled. When the number of strokes is changed over time, such as changes, there is a problem that the phase of the reciprocating motion gradually changes and the pump operation becomes unstable.

Images