Fuel pump

Patent metadata

Field	Value
Publication number	US-10934985-B2
Application number	US-201515542758-A
Country	US
Kind code	B2
Filing date	Dec 21, 2015
Priority date	Jan 15, 2015
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

An inner gear includes: sliding surface parts that are provided annularly at an outer peripheral part including a plurality of outer teeth on both sides of the inner gear in its axial direction and that slide on a pump housing; recessed parts that are respectively provided radially inward of the sliding surface parts to respectively form fuel chambers, into which fuel flows, between the recessed parts and the pump housing; and a communication hole that communicates between the recessed parts. The inner gear further includes an inclined surface part that is provided at an edge portion of a communicating edge portion on a rotation advance side of the inner gear, to avoid an adjacent part adjacent to an inner peripheral edge portion of each of the sliding surface parts and that is inclined further toward a rear side in a direction to a central part of the communication hole.

First claim

The invention claimed is:

1. A fuel pump comprising:
an outer gear that includes a plurality of inner teeth;
an inner gear that includes a plurality of outer teeth and is eccentric from the outer gear in an eccentric direction to be engaged with the outer gear; and
a pump housing that rotatably accommodates the outer gear and the inner gear, wherein:
the outer gear and the inner gear expand and contract volume of a plurality of pump chambers formed between both the gears, and rotate to sequentially suction fuel into the plurality of pump chambers and then discharge fuel from the plurality of pump chambers;
the inner gear includes:
sliding surfaces that are annular and at an outer peripheral part including the plurality of outer teeth respectively, that are on both axial sides of the inner gear, and that slide on the pump housing;
recessed parts that are radially inward of the sliding surfaces and that form fuel chambers, into which fuel flows, between the recessed parts and the pump housing; and
a communication hole that communicates between the recessed parts; wherein
an edge portion of an opening of the communication hole includes an inclined surface on a rotation advance side of the inner gear, but not extending beyond a part of the edge portion adjacent to an inner peripheral edge portion of each of the sliding surfaces, and a first portion of the inclined surface is inclined away from a bottom of the recessed part and toward a central part of the communication hole, and a second portion of the inclined surface extends in parallel with an inner central line of the inner gear along its axial direction.

2. The fuel pump according to claim 1 , wherein the inclined surface is also on a rotation reverse side of the inner gear but not extending beyond the part of the edge portion adjacent to the inner peripheral edge portion of each of the sliding surfaces.

3. The fuel pump according to claim 1 , wherein the inclined surface is also on an opposite side of the opening from the inner peripheral edge portion.

4. The fuel pump according to claim 1 , wherein the inclined surface is provided at the opening of the communication hole on both sides that communicate respectively with the recessed parts.

5. The fuel pump according to claim 1 , wherein the communication hole is one of a plurality of communication holes that are provided along a rotation direction of the inner gear.

6. The fuel pump according to claim 5 , further comprising:
an electric motor that includes a rotation shaft, which rotates the inner gear; and
a joint member that connects the rotation shaft with the inner gear via leg parts respectively corresponding to the plurality of communication holes, wherein each of the leg parts of the joint member is inserted in a corresponding one of the plurality of communication holes with a clearance therebetween.

7. The fuel pump according to claim 6 , wherein the pump housing includes a housing space that communicates with one of the recessed parts to house the joint member.

8. The fuel pump according to claim 1 , wherein light oil as fuel flows into the recessed parts.

Assignees

• Denso Corp

Inventors

• Sakai Hiromi
• Furuhashi Daiji

Classifications

• F04C15/008

  Prime movers · CPC title

• F04C2/102

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

• F04C2210/203

  Fuel · CPC title

• F04C11/008

  Enclosed motor pump units · CPC title

• F02M37/10

  submerged in fuel, e.g. in reservoir · CPC title