Motor-integrated internal gear pump, method of producing the gear pump, and electronic apparatus

Abstract

A motor-integrated internal gear pump that is inexpensive and highly reliable while maintaining characteristics of small size and inexpensive functions. The motor-integrated internal gear pump (80) has a pump section (81) with an inner rotor (1), an outer rotor (2), a pump casing, and an inner shaft (5). The pump casing has flat inner surfaces facing both end surfaces of each of the inner rotor (1) and the outer rotor (2). The inner shaft (5) has a bearing section (51) inserted into a shaft hole of the inner rotor (1) and fitting sections (53) extending axially outward from both end surfaces of the inner shaft (51). The pump casing is constructed from two pump casing members (3, 4) where the flat inner surfaces (25, 26) are formed as separate members. The fitting sections (53) of the inner shaft (5) are fitted in fitting holes (27a, 28a) formed in the flat inner surfaces of the two pump casing members (3, 4), and the two pump casing members (3, 4) are joined to each other at a position more on the outside than the outer diameter of the outer rotor, with the flat inner surfaces (25, 26) made to be in contact with both end surfaces of the bearing section (51).

Description

technical field [0001] The present invention relates to a motor-integrated internal gear pump, a manufacturing method thereof, and an electronic device. Background technique [0002] The internal gear pump has been known for a long time as a pump that sends out the sucked liquid against the pressure, and it is especially popular as a hydraulic source pump or an oil supply pump. [0003] The internal gear pump is composed of a spur gear-shaped inner rotor with teeth formed on the outer circumference, and an annular outer rotor with teeth formed on the inner circumference and approximately the same width as the inner rotor as main active members. A housing is provided to accommodate the two rotors, and the housing has flat inner surfaces facing the two side surfaces of the rotors with a slight gap. The number of teeth of the inner rotor is usually one less than the number of teeth of the outer rotor, and they rotate in the same manner as the gear for power transmission in a s...

AI Technical Summary

Problems solved by technology

In the case of the above structure, it is difficult to precisely limit the distance between the parts of the two thrust bearings that face the internal gear and the external gear, and the frictional resistance when the internal gear, the external gear and the two thrust bearings rotate increases. , it is difficult to rotate in extreme cases

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