Electric pump

Patent metadata

Field	Value
Publication number	US-9810223-B2
Application number	US-201314029605-A
Country	US
Kind code	B2
Filing date	Sep 17, 2013
Priority date	Sep 20, 2012
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

An electric pump includes a motor rotor provided in a first end region in the axial direction of a rotary shaft, a pump rotor provided in a second end region in the axial direction of the rotary shaft, and a pump housing supporting the rotary shaft. The pump housing has a first housing portion for accommodating the pump rotor and a second housing portion having a blocking portion. The first housing portion has a suction port for drawing in fluid and a discharge port for discharging the drawn-in fluid.

First claim

What is claimed is:

1. An electric pump comprising:
a rotary shaft having a first end region and a second end region in an axial direction;
a motor rotor located in the first axial end region of the rotary shaft;
a pump rotor located in the second axial end region of the rotary shaft; and
a pump housing, which rotationally supports the rotary shaft and holds the pump rotor, wherein
the pump housing includes a first housing portion and a second housing portion, the first housing portion having an accommodating recess, which opens toward the motor rotor and accommodates the pump rotor, the second housing portion having a blocking portion closing the accommodating recess,
the accommodating recess and the blocking portion form a pump chamber, and
the first housing portion has a suction port for drawing fluid into the pump chamber and a discharge port for discharging the fluid drawn into the pump chamber to the outside of the pump chamber, wherein
the first housing portion has a first shaft supporting hole,
the second housing portion has a second shaft supporting hole,
the pump housing supports the rotary shaft via the first shaft supporting hole at a first side of the pump rotor in the axial direction and supports the rotary shaft via the second shaft supporting hole at a second side of the pump rotor in the axial direction,
the rotary shaft is supported by the pump housing such that a bearing clearance in the radial direction is provided between the rotary shaft and an inner surface of each of the first and second shaft holes,
the pump rotor is an internal gear pump rotor that includes an inner rotor and an outer rotor, the inner rotor being fixed to the rotary shaft to rotate integrally with the rotary shaft, and the outer rotor being rotationally accommodated in the accommodating recess and meshing with the inner rotor,
the inner rotor is configured such that a clearance in the axial direction is provided between the inner rotor and an inner bottom surface of the accommodating recess and between the inner rotor and the blocking portion, and
the size of the axial clearance is determined such that the inner rotor is separated from the inner bottom surface of the accommodating recess and the blocking portion even if the tilting of the rotary shaft is maximized in a range allowable in relation to the bearing clearance.

2. The electric pump according to claim 1 , wherein
the first housing portion has a fitting recess, which is continuous to the accommodating recess and has an opening toward the motor rotor, and the second housing portion is fitted and fixed in the fitting recess.

3. The electric pump according to claim 2 , wherein
a retaining portion, which protrudes radially inward, is integrally formed with the open end of the fitting recess, and the retaining portion is configured to lock the second housing portion in the axial direction.

Assignees

• Asmo Co Ltd

Inventors

• Irie Masaru
• Matsuura Toshihiro

Classifications

• F04C2/102

  the two members rotating simultaneously around their respective axes · CPC title

• F04D25/0693

  Details or arrangements of the wiring · CPC title

• F04C11/008

  Enclosed motor pump units · CPC title

• F04D13/06 Primary

  the pump being electrically driven · CPC title

• F04C2240/808

  Electronic circuits (e.g. inverters) installed inside the machine · CPC title