Rolling diaphragm pump

Patent metadata

Field	Value
Publication number	US-11313361-B2
Application number	US-201816963138-A
Country	US
Kind code	B2
Filing date	Nov 6, 2018
Priority date	Jan 19, 2018
Publication date	Apr 26, 2022
Grant date	Apr 26, 2022

Abstract

A rolling diaphragm pump that can inhibit an increase in cost with a simple configuration is provided. A rolling diaphragm pump 1 includes: a housing 2; a piston 3 disposed so as to be slidable relative to an inner peripheral surface of the housing 2 and reciprocatable in an axial direction; a rolling diaphragm 4 having a movable portion 41 disposed at one end portion in the axial direction of the piston 3 and reciprocatable together with the piston 3, a fixed portion 42 fixed to the housing 2, and a flexible connecting portion 43 connecting the movable portion 41 and the fixed portion 42 to each other; a pump chamber 5 defined by the rolling diaphragm 4 at one side in the axial direction within the housing 2 and into and from which a transport fluid is sucked and discharged by changing a volume of an interior of the pump chamber 5 by deformation of the connecting portion 43 due to reciprocation of the piston 3; and a working fluid chamber 6 defined by another end portion in the axial direction of the piston 3 at another side in the axial direction within the housing 2 and into and from which a working fluid is supplied and discharged, thereby causing the piston 3 to reciprocate.

First claim

The invention claimed is:

1. A rolling diaphragm pump comprising:
a housing;
a piston disposed so as to be slidable relative to an inner peripheral surface of the housing and reciprocatable in an axial direction of the housing;
a rolling diaphragm having a movable portion disposed at one end portion in the axial direction of the piston and reciprocatable together with the piston, a fixed portion fixed to the housing, and a flexible connecting portion connecting the movable portion and the fixed portion to each other;
a pump chamber defined by the rolling diaphragm at one side in the axial direction within the housing and into and from which a transport fluid is sucked and discharged by changing a volume of an interior of the pump chamber by deformation of the connecting portion due to reciprocation of the piston;
a working fluid chamber defined by another end portion in the axial direction of the piston at another side in the axial direction within the housing and into and from which a working fluid is supplied and discharged, thereby causing the piston to reciprocate,
wherein the piston includes a sliding portion slidable relative to the inner peripheral surface of the housing, a closely-contacted portion having an outer peripheral surface with which the deformed connecting portion can be brought into close contact, and a connection portion connecting the sliding portion and the closely-contacted portion to each other;
a decompression chamber whose pressure is reduced to a predetermined pressure is defined, by the sliding portion and the connecting portion, between the inner peripheral surface of the housing and the outer peripheral surface of the piston; and
a stopper projecting into the decompression chamber and configured to restrict movement of the sliding portion to the one side in the axial direction with respect to a predetermined position is integrally formed on the inner peripheral surface of the housing in the decompression chamber,
wherein the stopper includes a ventilation port communicating with the decompression chamber and penetrating from an outer peripheral surface of the housing toward an inner peripheral surface of the stopper.

2. The rolling diaphragm pump according to claim 1 , wherein
the sliding portion, the closely-contacted portion, and the connection portion are formed as a single member.

3. The rolling diaphragm pump according to claim 1 , wherein the stopper has a shorter axial length than the sliding portion.

4. The rolling diaphragm pump according to claim 1 , further comprising:
a permanent magnet attached to an outer periphery of the connection portion and configured to reciprocate together with the piston; and
a proximity sensor provided on the outer peripheral surface of the housing and configured to detect a magnetism of the permanent magnet,
wherein the stopper is formed on the inner peripheral surface of the housing, at a position where the permanent magnet comes into contact with the stopper when the piston moves to the predetermined position.

5. The rolling diaphragm pump of claim 1 , wherein the movable portion of the rolling diaphragm is fitted into a recess of the closely-contacted portion of the piston through tapered surfaces provided in opposing surfaces of the movable portion and the closely-contacted portion.

Assignees

• Nippon Pillar Packing

Inventors

• Teshima Kazukiyo
• Urata Daisuke

Classifications

• F04B43/0054

  particularities of the flexible members · CPC title

• F04B43/067

  the fluid being actuated directly by a piston · CPC title

• F04B2201/0201

  Position of the piston · CPC title

• F04B43/06 Primary

  Pumps having fluid drive · CPC title

• F05B2210/11

  liquid, i.e. incompressible · CPC title