Pump device

Abstract

A pump device may include an eccentric member mounted on an output shaft in an eccentric manner, a cam mechanism which is engaged with the eccentric member to convert a motion of the output shaft into a radial direction and at least one pump body which includes a diaphragm that is moved in the radial direction in relation to the output shaft by the cam mechanism for performing a pumping operation.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] The present invention claims priority under 35 U.S.C. § 119 to Japanese Application No. 2004-166205 filed Jun. 3, 2004, which is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates to a pump device for circulating fluid. More specifically, the present invention relates to a pump device provided with a pump body utilizing a diaphragm. BACKGROUND OF THE INVENTION [0003] A conventional circulating pump 100 has been known in which a plurality of pump bodies 102 are provided for sucking and compressing fluid by means of the operation of diaphragms 101 and the diaphragms 101 of the respective pump bodies 102 are disposed on the same plane as shown in FIG. 26 (see Japanese Patent Laid-Open No. Hei 11-62837). The circulating pump 100 includes a motor 103 as a drive source, a rotation shaft 104 rotated by the motor 103 and provided with an end face slightly inclined with respect to its rotation center, a ...

AI Technical Summary

Benefits of technology

[0007] In view of the problems described above, the present invention may advantageously provide a pump device that can be easily miniaturized and can obtain a little flow rate.

[0011] In accordance with an embodiment of the present invention, the cam mechanism may preferably include a contact ring which is rotatably mounted with respect to the eccentric member and, when the eccentric member is rotated, the contact ring makes the diaphragm move in the radial direction of the output shaft while the contact ring relatively rotates with respect to the eccentric member. When the cam mechanism is constructed such that the contact ring makes the diaphragm move in the radial direction while the contact ring is relatively rotated with respect to the eccentric member, the contact ring does not perform the operation of pushing while rotating with respect to the diaphragm and thus the movement of the diaphragm in the radial direction can be stably performed.

[0013] In accordance with an embodiment of the present invention, the projecting part of the diaphragm may be preferably covered with a fluorine coating or material having an abrasion resistance property and a low friction coefficient for the improvement of durability and the reduction of contact resistance.

[0014] In accordance with an embodiment of the present invention, a plurality of pump bodies may be four pump bodies which are disposed around the cam mechanism at every 90 degrees with an equal distance, and only one of the four pump bodies is preferably operated by the contact ring at a time. When only one of the four pump bodies can be operated by the contact ring at a time, an output with a little flow rate can be easily obtained.

[0017] According to the pump device described above in accordance with an embodiment of the present invention, since the cam mechanism makes the diaphragm move in the radial direction of the output shaft, the diaphragms are not required to be disposed on the same plane as the conventional example, and thus the downsizing of the pump device can be easily attained.

[0018] Further, when a stepping motor is used as the motor, the cam mechanism can be controlled by a little angle and thus a little flow rate can be obtained by means of operating only one pump at a time. As a result, the applicable scope of the pump device can be extended.

Problems solved by technology

However, in the above-mentioned circulating pump 100, the diaphragms 101 are disposed on the same plane and thus downsizing is difficult while maintaining the size of the pump body 102.

Therefore, it is difficult to operate only one of the pump bodies 102 at a time in order to obtain a little flow rate.

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