Impeller for fuel pump and fuel pump in which the impeller is employed

Abstract

An impeller is employed for a fuel pump and boosts a pressure of fuel by rotating the fuel in a pump passage formed in the fuel pump in a rotational direction of the impeller. The impeller includes a plurality of vane grooves formed adjacent to each other in the rotational direction of the impeller and a plurality of vanes formed adjacent to each other in the rotational direction. Each one of the plurality of vanes divides one of adjacent two of the plurality of vane grooves from the other. A difference between a maximal value and a minimum value of an adjacent vane angle is set in a range of 2.5° to 4°. A fuel pump includes a motor unit, the impeller, and a casing member. The impeller is rotated by rotation driving force of the motor unit. The casing member rotatably receives the impeller and defines the pump passage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with additional objectives, features and advantages thereof, will be best understood from the following description, the appended claims and the accompanying drawings in which:

FIG. 1A is an overall view of an impeller viewed from a fuel inlet side according to according to a first embodiment of the present invention;

FIG. 1B is an enlarged view of an area near vane grooves shown in FIG. 1A;

FIG. 2 is a cross-sectional view of a fuel pump according to the first embodiment;

FIG. 3A is a schematic view of the vane grooves of the impeller viewed from the fuel inlet side according to the first embodiment;

FIG. 3B is a cross-sectional view taken along a line IIIB-IIIB in FIG. 3A;

FIG. 4 is an enlarged view of pump passages shown in FIG. 2;

FIG. 5 is a graph showing a relationship between a dispersion range and a peak of a sound pressure and a relationship between the dispersion range and pump efficiency;

FIG. 6 is a graph showing a relationship between an adjacent vane angle and the pump efficiency;

FIG. 7 is an overall view of an impeller viewed from a fuel inlet side according to a second embodiment of the present invention;

FIG. 8A is a graph showing the peak of the sound pressure of vanes at regular intervals; and

FIG. 8B is a graph showing the peak of the sound pressure of vanes at irregular intervals.

Claims

1. An impeller that is employed for a fuel pump and boosts a pressure of fuel by rotating the fuel in a pump passage, which is formed in the fuel pump in a rotational direction of the impeller, the impeller comprising: a plurality of vane grooves formed adjacent to each other in the rotational direction of the impeller; anda plurality of vanes formed adjacent to each other in the rotational direction of the impeller, wherein: each one of the plurality of vanes divides one of adjacent two of the plurality of vane grooves from the other; anda difference between a maximal value and a minimum value of an adjacent vane angle is set in a range of 2.5° to 4°, wherein the adjacent vane angle is an angle, which is made around a rotational axis of the impeller between respective ends of adjacent two of the plurality of vanes in the rotational direction of the impeller.

2. The impeller according to claim 1, wherein each adjacent vane angle is set in a range of 8° to 12°.

3. A fuel pump comprising: a motor unit;the impeller recited in claim 1, wherein the impeller is rotated by rotation driving force of the motor unit; anda casing member that rotatably receives the impeller and defines the pump passage.