Nippon Pillar Packing Co., Ltd.

Hitoshi Kawamura

Kiyoshi Nishio

Makoto Fujii

Masayoshi Katsura

Kazukiyo Teshima

Tomoyuki Koike

Toshihide Iida

Ryo Imanishi

Yoji Minato

A suction passage () and a discharge passage () for a to-be-transferred fluid are disposed in a pump body (). A bottomed cylindrical bellows () is integrally coupled to the axial rear side of the pump body to form a closed space (). The suction passage () has an upstream portion (A) having a larger diameter and a predetermined passage cross section area, and downstream portions (B) which are formed by branching the upstream portion into a bifurcated or Y-shape while reducing the passage cross section area. Two first small check valves () of the spring type in each of which the pressure receiving area is reduced in accordance with the reduced passage cross section areas of the smaller-diameter downstream portions (B) are attached respectively to outlet portions of the smaller-diameter down-stream portions (B) so as to be arranged in parallel. The outlets of the first check valves () are opened in the closed space ().

Reciprocating pump

In a pump employing a bellows, individual members are formed from resins and pump components including a fitted assembly formed by fitting plural members with each other form a structure unit which is tightly inserted in an external cover and constrained on the opposite ends thereof for come off prevention. Thus, the distortion or deformation of the members during assembly is obviated and hence, a good sealing performance is achieved.

Fitted assembly bellows pump

A bellows that is extendingly and contractingly deformable in the axial direction is placed in a pump body and forms a liquid chamber inside the bellows. A suction portion and a discharge portion are formed in an inner bottom face of the pump body facing the liquid chamber. Liquid is sucked from the suction port into the liquid chamber by extension of the bellows, and the liquid in the liquid chamber is discharged from the discharge portion by contraction of the bellows. The extending and contracting portion of the bellows which is configured by forming ridge-like folds and valley-like folds in a vertically alternate and continuous manner is formed into a shape in which the lower one of upper and lower lamella portions of each of the ridge-like folds, or the lower lamella portion is inclined downwardly toward the axis defining the axial direction, not only in an extending state but also in a contracting state. Even in the case where liquid containing a sedimenting material such as slurry is used, therefore, the sedimenting material can be prevented from sedimenting and stagnating in the extending and contracting portion of the bellows.

Fluid apparatus having downwardly inclined lower lamella portion of a bellows

A fluid device capable of preventing sediment from stagnating and accumulating in a liquid chamber of a pump when a transfer liquid containing sediment such as slurry is used, wherein a suction port ( ) and a delivery port ( ) and a diaphragm ( ) are installed in the pump main body ( ), the suction port ( ) is provided in the side face of a projected tip part of the pump main body, and a suction liquid is sprayed toward a circular wall inside a liquid chamber ( ), thus causing swirl flow, whereby the inside of the liquid chamber is agitated.

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Sanda, Japan

Hitoshi Kawamura