DE-102007000068-B4 - Engine and the fuel pump using the engine

DE102007000068B4DE 102007000068 B4DE102007000068 B4DE 102007000068B4DE-102007000068-B4

Abstract

engine with a stator core (30a) having a plurality of coil cores (32a) arranged circumferentially, wherein each of the multitude of coil cores (32a) a tooth (34a) extending radially, and an outer edge core (36a) extending circumferentially on a radially outer side of the tooth (34a), and ends in the circumferential direction of an inner edge surface (37a) of the outer edge core (36a) with respect to an imaginary straight line (100) connecting the ends in the circumferential direction of the inner edge surface (37a) of the outer edge core (36a), with the ends approaching circumferentially adjacent coil cores (32a) arranged more radially inwards, insulators (40a), each covering a corresponding plurality of coil cores (32a), wherein a side of a coil winding surface (46a) of each insulator (40a) facing the outer edge core (36a) extends along the imaginary straight line (100), coils (48), each wound on a corresponding insulator (40a), and a rotor (60) which is rotatable to an inner circumferential side of the stator core (30a), wherein different magnetic poles are arranged alternately in the direction of rotation on an outer edge surface of the rotor (50), and the outer surface of the rotor (60) faces the stator core (30a), wherein the imaginary straight line (100) is positioned on a side of the coil winding surface (46a) facing the outer edge core (36a), α is defined as an inclination angle with which the ends are inclined radially inwards in the direction of rotation of the inner edge surface (37a) of the outer edge core (36a) with respect to the imaginary straight line (100) connecting the ends in the direction of rotation of the inner edge surfaces (37a) of the outer edge core (36a), as the ends approach adjacent coil cores (32a) arranged circumferentially in the direction of rotation, where, if the coil cores (36a) are four coil cores (36a), 40° ≤ α ≤ 50° holds true, if the coil cores (36a) are six coil cores (36a), 25° ≤ α ≤ 35° applies, and if the coil cores (36a) are eight coil cores (36a), then 17.5° ≤ α ≤ 27.5° applies.

Inventors

Hiromi Sakai
Kiyoshi Nagata

Assignees

AISAN KOGYO KABUSHIKI KAISHA

Dates

Publication Date: 20260513
Application Date: 20070201
Priority Date: 20060202

Claims (3)

Motor with a stator core (30a) having a plurality of coil cores (32a) arranged circumferentially, wherein each of the plurality of coil cores (32a) has a tooth (34a) extending radially, and an outer edge core (36a) extending circumferentially on a radially outer side of the tooth (34a), and ends in the circumferential direction of an inner edge surface (37a) of the outer edge core (36a) with respect to an imaginary straight line (100) connecting the ends in the circumferential direction of the inner edge surface (37a) of the outer edge core (36a), with the ends approaching circumferentially adjacent coil cores (32a) arranged circumferentially being inclined more radially inwards, insulators (40a) each covering a corresponding plurality of the coil cores (32a), wherein a side facing the outer edge core (36a) of The coil winding surface (46a) of each insulator (40a) extends along the imaginary straight line (100), coils (48) each wound on a corresponding insulator (40a), and a rotor (60) rotatably arranged relative to an inner circumferential side of the stator core (30a), wherein different magnetic poles are alternately arranged in the direction of rotation on an outer edge surface of the rotor (50), and the outer edge surface of the rotor (60) faces the stator core (30a), where the imaginary straight line (100) is positioned on a side of the coil winding surface (46a) facing the outer edge core (36a), α is defined as an angle of inclination at which the ends are inclined in the direction of rotation of the inner edge surface (37a) of the outer edge core (36a) with respect to the imaginary straight line (100) that forms the ends in The direction of rotation of the inner edge surfaces (37a) of the outer edge core (36a) connects, with the ends approaching adjacent coil cores (32a) arranged circumferentially inwards in the direction of rotation, whereby, if there are four coil cores (36a), 40° ≤ α ≤ 50° applies, if there are six coil cores (36a), 25° ≤ α ≤ 35° applies, and if there are eight coil cores (36a), 17.5° ≤ α ≤ 27.5° applies.
Engine after Claim 1 , wherein the side of the coil winding surface (46a) of each insulator (40a) facing the outer edge core (36a), which extends along the imaginary straight line (100), is a flat surface.
fuel pump with a motor (14a) after Claim 1 or 2 , and a pump (12) driven by the motor (14a), wherein the pump (12) takes in fuel and increases the pressure of the fuel.

Description

The present invention relates to a brushless motor with an internal rotor and a fuel pump that uses this. A conventional fuel pump that uses a brushless motor with an internal rotor as its drive source reveals (compare, for example, JP 2005 - 110 478 A according to the US 2005 / 0 074 343 A1 , JP 2005 - 110 477 A In a brushless motor, no loss problems arise similar to those in a brushed motor due to frictional resistance between the commutator and brush, electrical resistance between the commutator and brush, and flow resistance caused by the slots used to divide the commutator into segments. As a result, the motor efficiency of the brushless motor is higher than that of the brushed motor, thus improving the efficiency of the fuel pump. The efficiency of the fuel pump is given by (motor efficiency) x (pump efficiency). If I represents a drive current supplied to the fuel pump motor, V represents an applied voltage, T represents a torque of the motor, N represents a speed of the motor, P represents the pressure of the fuel pumped by the fuel pump, and Q represents a fuel pump size, then the motor efficiency and the pump efficiency can be described as (motor efficiency) = (T × N)/(I × V) and (pump efficiency) = (P × Q)/(T × N). Therefore, (fuel pump efficiency) = (motor efficiency) × (pump efficiency) = (P × Q)/(I × V). Then the fuel pump using the brushless motor can be reduced in size, since the size of the motor can be reduced for the equivalent motor efficiency in a case where a brushless motor is used instead of the brushed motor. The printed matter US 2004/015287 A1 Disclosing an electric motor, the stator of which consists of six sectors, each with inwardly facing teeth, is a coil former. A coil former is arranged on each tooth. The winding is arranged on the coil former, which has flat flanges. A tooth-facing side of a coil winding surface on the coil former and the inner edge surface of the yoke section belonging to each sector are located outside a straight line defined by the ends of the yoke's inner surface of the sector. The printed matter EP 0 871 282 A1 Disclosure reveals another electric motor comprising a coil core with a wound coil former on it. The side of the coil former facing the outer edge of the core extends along an imaginary line connecting the inner ends of the yoke portion of the coil core. The side of the inwardly facing surface of the yoke portion of the coil core facing the tooth is concave near the edge. The printed matter DE 19857954 A1 reveals another electric motor in which the pole stator is composed of several circular ring segments. The inventors of the present application have studied a structure for a brushless motor with an internal rotor to easily wind a coil winding wire with a high space factor within a limited winding space of each coil core. This is achieved by reducing the size of the motor through the use of a stator core, by surrounding an outer edge of the rotor with a plurality of coil cores arranged radially. The space factor is the ratio of the cross-sectional area of the winding wire to the winding space. That is, a higher space factor allows for an increased number of turns of the winding wire within the winding space, thus reducing the size of the motor and improving its efficiency. With a coil core 300, which forms a stator core and as in 9 As shown, an inner edge surface 305 of an outer edge core 304 extends circumferentially around a radially outer side of a tooth 302 of the coil core 300 and is generally positioned on an imaginary straight line 330 passing through ends in the circumferential direction of the inner edge surface 305. A side of a coil winding surface 312 of an insulator 310, on or around which a coil 320 is wound, facing the outer edge core 304, extends along the imaginary straight line 330. If the side of the coil winding surface 312 of the insulator 310 facing the outer edge core 304 extends along the imaginary straight line 330, as described above, the winding wire can be easily wound in the winding spaces of the insulator 310 from openings in the insulator 310. In a coil core 300, which forms a stator core and as in 9 As shown, the inner edge surface 305 of an outer edge core 304 is a flat surface, and the outer edge core 304 extends circumferentially around a radially outer side of a tooth 302. Furthermore, an imaginary straight line 330, connecting ends in the circumferential direction of the inner edge surface 305, is arranged on the inner edge surface 305. A The side of the coil winding surface 312 of the insulator 310 facing the outer edge core 304, onto which a coil 320 is wound, is a flat surface along the imaginary straight line 330. If the coil winding surface 312 of the insulator 310 on the side of the outer edge core 304 is the flat surface along the imaginary straight line 330, as described above, the winding wire can be easily wound in the winding spaces of the insulator 310 from openings in the insulator 310. However,