JP2003116248A - Vehicle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor 2 having little vibrations and a fuel pump using the motor by a method wherein an inclination suppressing means which suppresses an inclination of an axis of an armature 22 relative to the axes of both bearings 23 and 24. SOLUTION: An imaginary plane P, which is perpendicular to the bisector of an angle between lines connecting a shaft center Ca of an armature 22 with centers Cb of respective brushes 21, and further, includes the shaft center Ca of the armature 22, is provided. A second magnet 28 is provided in a space on one side of the plane P so as to face the respective brushes 21 with a plane P between. The center 28a of the second magnet 28 in its axial direction is shifted from a center 222a of a core 222 in its axial direction by a length D in the direction of a first pressing force Fb. With such a constitution, angular moment Mb applied to the armature 22 by the brushes 21 is canceled and the inclination of the armature 22 is eliminated, so that the vibration of the motor 2 in operation can be suppressed and the vibration of a fuel pump 1 can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor for a vehicle, and is suitable for use as an electric motor for driving a fuel pump installed in a fuel tank of an automobile as a vehicle.

[0002]

2. Description of the Related Art As a conventional electric motor, for example, a 4-pole 6 as disclosed in Japanese Patent Laid-Open No. 11-69747 is used.
There is a slot concentrated winding type. This electric motor is characterized in that there is no overlapping of windings, the space factor can be increased, and the efficiency of the electric motor can be increased. Further, in such a 4-pole 6-slot electric motor, it is necessary to arrange the brushes at 90-degree intervals.

By the way, in automobiles, as a part of energy saving, there is a strong demand for reduction of power consumption and improvement of efficiency of the on-vehicle electric motor.
In order to improve the efficiency of the vehicle fuel pump drive electric motor installed in the fuel tank for transferring fuel to the engine,
The adoption of the above-mentioned electric motor having a 4-pole 6-slot configuration is under study. Conventionally, in an electric motor of a fuel pump for a vehicle, a commutator has a disk shape and a pair of brushes are arranged in parallel with the axis of the armature and axially symmetric, that is, at intervals of 180 degrees in order to reduce the outer diameter dimension as much as possible. The coil spring, which is a biasing means, applies a pressing force parallel to the axis of the armature to the brush to bring the brush into axial contact with the commutator. In this case, the pressing force of the brush causes the armature to generate a rotational moment that causes the armature to rotate about an axis that passes through the center of gravity of the armature and is orthogonal to the axis. The armature is rotatably supported on both ends by the shaft axis of the shaft. A gap required to smoothly rotate the armature is formed between the shaft and the bearing. For this reason, when the above-mentioned rotational moment acts on the armature, the shaft moves by the gap in the bearing, and the armature tilts.

However, the pair of brushes are arranged at intervals of 180 degrees, and the pressing force of each brush against the commutator is set to be substantially equal. Therefore, since the rotational moments due to the pressing force of the brushes have the same magnitude and the rotational directions are opposite to each other, their combined moment becomes 0, and as a result, the armature does not tilt.

[0005]

On the other hand, when the electric motor of the above-mentioned 4-pole 6-slot structure is adopted as the electric motor of the vehicle fuel pump, the pair of brushes are arranged at 90-degree intervals. Therefore, a combined moment of each rotational moment is generated by the pressing force of each brush, whereby the armature is tilted and the shaft is one-sided against the bearing. That is, at one end of the armature, that is, at the commutator-side bearing, the shaft is in partial contact with the brush side, and in the bearing at the other end of the armature, the shaft is in partial contact with the side facing the brush. When the armature rotates with the shaft tilted in this way, the unbalanced weight of the armature increases, and the vibration of the electric motor increases. Normal,
Since the vehicular fuel pump is fixed in the fuel tank, when the vibration of the electric motor of the vehicular fuel pump increases, the vibration is transmitted to the fuel tank and noise is generated. Further, since the fuel tank is usually mounted below or behind the passenger compartment of the vehicle, noise generated by the fuel tank may cause occupant discomfort. Further, when the armature is tilted and the shaft is operated against the bearing, the bearing is partially worn, which further increases the vibration of the electric motor.

The present invention has been made in view of the above points, and an object thereof is to provide an electric motor for a vehicle with small vibration by providing an inclination suppressing means for suppressing the inclination of the armature with respect to the axis of the bearing. Especially.

[0007]

In order to achieve the above object, the present invention employs the following technical means.

According to a first aspect of the present invention, there is provided a vehicle electric motor having a tilt suppressing means for suppressing an inclination of the shaft axis with respect to the bearing axis due to the first pressing force. did. As a result, during operation of the vehicle electric motor, the shaft does not tilt with respect to the axis line of the bearing, in other words, the axis line of the shaft can be kept substantially parallel to the axis line of the bearing, so that the vehicle electric motor with small vibration can be provided. Can be provided.

In the electric motor for a vehicle according to claim 2 of the present invention, a pressing member arranged parallel to the axis of the armature,
A second urging means for urging the pressing member in the axial direction of the armature is provided, and the pressing member is a corner of the commutator formed by a line segment connecting the axis of the armature and the center of each brush. A portion facing the brush with a straight line orthogonal to the dividing line and passing through the axis of the armature sandwiched between the second biasing means and the second portion.
It is configured to be pressed with the pressing force of. This allows
The second pressing force of the pressing member acts on the armature with a rotational moment whose magnitude is equal to the combined moment of the respective rotational moments acting on the armature by the first pressing force of each brush and whose rotation direction is opposite. Let
Since the combined moment of each rotational moment acting on the armature by the first pressing force of each brush and the rotational moment acting on the armature by the second pressing force of the pressing member can be set to 0, the operation of the vehicle electric motor can be performed. In the inside, the shaft is not inclined with respect to the axis line of the bearing, in other words, the axis line of the shaft can be kept substantially parallel to the axis line of the bearing, so that it is possible to provide the vehicle electric motor with small vibration.

In the electric motor for a vehicle according to a third aspect of the present invention, the pressing member has a bisector of an angle formed by a line segment connecting the axis of the armature and the center of each brush on the end surface of the other end of the armature. The portion included in the space on the brush side of the plane orthogonal to the line and including the axis of the armature is pressed by the second pressing force by the second biasing means. As a result, the second pressing force of the pressing member applies a rotational moment that is equal in magnitude and opposite in rotational direction to the combined moment of the rotational moments acting on the armature by the first pressing force of each brush. Since the combined moment of each rotational moment acting on the armature by the first pressing force of each brush and the rotational moment acting on the armature by the second pressing force of the pressing member can be made 0, During operation of the electric motor for a vehicle, the shaft does not incline with respect to the axis of the bearing. In other words, the axis of the shaft can be kept substantially parallel to the axis of the bearing, so that it is possible to provide the electric motor for a vehicle with small vibration.

In the electric motor for a vehicle according to a fourth aspect of the present invention, a part of the first magnet is configured as a second magnet as the tilt suppressing means, and the second magnet serves as an axis of the armature. Included in the space on the side facing the brush across a plane that is orthogonal to the bisector of the angle formed by the line segment that connects the centers of the brushes and that sandwiches the plane that includes the axis of the armature.
The axial center of the magnet is arranged substantially axially with respect to the axial center of the armature core, and the axial center of the second magnet is first pressed against the axial center of the armature core. It is arranged so that it is displaced in the same direction as the direction of force. In this case, the amount of leakage magnetic flux between the end faces of the armature and the second magnet is not uniform.
That is, the amount of leakage flux on the other end side of the armature is larger than the amount of leakage flux on the one end side (commutator side) of the armature. As a result, a tensile force in the same direction as the direction of the first pressing force of the brush acts on the portion of the armature facing the second magnet, and this tensile force causes a rotational moment in the armature. A pulling force of the second magnet is applied to the armature to exert a rotation moment whose magnitude is equal to the combined moment of the respective rotation moments acting on the armature by the first pressing force of each brush and whose rotation direction is opposite. , The combined moment of each rotational moment acting on the armature by the first pressing force of each brush and the rotational moment acting on the armature by the tensile force of the second magnet can be set to 0, so that the operation of the electric motor for a vehicle can be performed. In the inside, the shaft does not incline with respect to the axis line of the bearing, in other words, the axis line of the shaft can be held substantially parallel to the axis line of the bearing, so that it is possible to provide a vehicle electric motor with small vibration.

In the vehicle electric motor according to claim 5 of the present invention, the second magnet is orthogonal to the bisector of the angle formed by the line segment connecting the axis of the armature and the center of each brush, and the armature. Included in the space on the brush side of the plane including the axis of
The axial center of the second magnet is arranged so as to be offset from the axial center of the armature core in the direction opposite to the direction of the first pressing force. As a result, a tensile force in a direction opposite to the direction of the first pressing force of the brush acts on the portion of the armature facing the second magnet. A pulling force of the second magnet is applied to the armature to exert a rotation moment whose magnitude is equal to the synthetic moment of each rotation moment acting on the armature by the first pressing force of each brush and whose rotation direction is opposite. , The combined moment of each rotation moment acting on the armature by the first pressing force of each brush and the rotation moment acting on the armature by the pulling force of the second magnet can be set to 0, so that the operation of the vehicle electric motor can be performed. In the inside, the shaft does not incline with respect to the axis of the bearing, in other words, the axis of the shaft can be kept substantially parallel to the axis of the bearing, so that it is possible to provide a vehicle electric motor with small vibration.

According to a sixth aspect of the present invention, in an electric motor for a vehicle, the armature has six salient poles in a radial pattern, and
The number of magnets is four, that is, four poles and six
It is a slot type electric motor. As a result, reduction of power consumption and improvement of efficiency of the vehicle electric motor can be achieved.

According to a seventh aspect of the present invention, in the vehicle electric motor, the shaft is formed in a hollow cylindrical shape, and the inner diameter portion of the shaft is rotatably fitted to the outer diameter portion of the bearing. I am trying. As a result, the weight of the vehicle electric motor can be reduced.

According to an eighth aspect of the present invention, by applying the vehicle electric motor according to any one of the first to seventh aspects of the present invention to a driving electric motor of a vehicle fuel pump, a vehicle fuel can be obtained. Vibration during operation of the pump can be suppressed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a case where a vehicle electric motor according to an embodiment of the present invention is applied to an electric motor driven vehicle fuel pump will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a vertical sectional view of a fuel pump 1 which is a vehicle fuel pump according to a first embodiment of the present invention. A sectional view taken along the line II-II of FIG. 1 is shown in FIG.

The fuel pump 1 is mounted in a fuel tank (not shown) of an automobile and supplies the fuel in the fuel tank to an engine (not shown).

The fuel pump 1 is composed of a motor 2 which is an electric motor for a vehicle and an eddy current pump 3 which is driven by the motor 2. The shaft 2 by the motor 2
The impeller 32 attached to the motor 23 is rotated to supply the fuel in the pump chamber 35 formed by the pump casing 33 and the pump cover 34 to the engine (not shown).

The vortex pump 3 includes a pump casing 33,
The pump cover 34 and the impeller 32 are included. A pump chamber 35 is constituted by the pump casing 33 and the pump cover 34, and the impeller 32 as a rotating body is rotatably accommodated therein. The pump casing 33 and the pump cover 34 are formed by die casting of aluminum, for example. The pump casing 33 is press-fitted and fixed inside one end of the housing 11, and the plane bearing 24 is fitted in the center thereof. The pump cover 34 is fixed to one end of the housing 11 by caulking or the like while being covered with the pump casing 33. The thrust bearing 25 is press-fitted and fixed to the center of the pump cover 34. Motor 2 armature 2
One end of the second shaft 223 is rotatably supported by a plane bearing 24 in the radial direction, and a thrust bearing 25 supports a load in the thrust direction (downward in FIG. 1). The other end of the shaft 223 is rotatably supported in the radial direction by a spherical bearing 23 fitted in the brush holder 12.

The suction port 31 is formed in the pump cover 34, and the impeller 32 having blades (not shown) formed on the peripheral edge thereof is rotated, so that the fuel in the fuel tank (not shown) is sucked into the suction port. It is sucked into the pump chamber 35 from 31. The pump chamber 35 is formed in a C shape between the pump casing 33 and the pump cover 34 along the outer circumference of the impeller 32. The fuel sucked into the pump chamber 35 is pressurized by the rotation of the impeller 32, is pressure-fed to the fuel chamber 13 of the motor 2, passes around the armature 22, and is discharged from the fuel pump 1 through the discharge port 36.

Next, the structure of the motor 2 will be described in detail.

The motor 2 is of a concentrated winding type having a 4-pole, 6-slot structure.

The commutator 221 is, as shown in FIGS.
Contact pieces 22 formed at equal angular intervals and facing each other by 180 °
Other than 1a, it has six conductive contact pieces 221a electrically insulated from each other. The contact piece 221 a is made of a conductive material having excellent wear resistance, for example, carbon, and slides in contact with the brush 21.

The armature 22 is formed by press-fitting and fixing a core 222, which is a magnetic material, for example, by laminating a large number of electromagnetic steel plates, onto a shaft 223. Also, FIG.
As shown in, the commutator 221 is fixed to the side of the core 222 opposite to the vortex pump 3. The core 222 has six salient poles (not shown) formed at equal angular intervals,
A coil (not shown) is wound around the groove between adjacent salient poles, that is, the slot (not shown). Both ends of each coil are electrically connected to each contact piece 221a of the commutator 221. In order to maintain the insulation of this connection portion and the coil and prevent corrosion due to fuel, the core 222
The commutator 221 is molded with resin 224. The end surface of the commutator 221 on the brush holder 12 side is exposed without being molded in order to make sliding contact with the brush 21.

The pair of brushes 21 are formed of a conductive material having excellent abrasion resistance, for example, carbon, and are accommodated in a guide portion 12a provided in the brush holder 12 so as to be movable in the axial direction, as shown in FIG. Has been done. Each brush 21
Are connected to each other on the commutator 221 as shown in FIGS.
It is arranged to form an angle of 0 degree. A pigtail (not shown) that is a conductor that electrically connects the brush 21 to the terminal 14 is joined to the brush 21. The pigtail is formed of a flexible stranded wire made of a large number of thin copper wires so as not to hinder the movement of the brush 21 in the guide portion 12a. Further, the brush 21 uses the brush spring 26, which is the first urging means, for the armature 2
The first pressing force Fb parallel to the axis of 2 is urged to contact the commutator 221.

Here, the first pressing force Fb of the brush 21
As a result, a rotation moment is generated in the armature 22 around its center of gravity. In the conventional fuel pump motor, since the pair of brushes 21 are arranged at 180-degree intervals, the combined moment of each rotational moment by each brush 21 is 0, that is, the armature 22 is rotated, in other words, the armature 22 is rotated. The tilting moment was zero. On the other hand, in the first embodiment of the present invention, since the pair of brushes 21 are arranged at intervals of 90 degrees, the combined moment of each rotational moment by each brush 21 does not become zero. That is, as shown in FIG. 1, a counterclockwise moment Mb that tilts the armature 22 is generated.

The brush holder 12 is made of an insulating material such as a thermoplastic resin and has a pair of guide portions 12a for accommodating the brush 21 movably in the axial direction. Further, the brush holder 12 is fitted with a spherical bearing 23 that rotatably supports the shaft 223 of the armature 22 in the radial direction. That is, the armature 22 is rotatably supported at its both ends in the radial direction by the spherical bearing 23 and the plane bearing 24 fitted in the pump casing 33 of the vortex pump 3.

On the outer peripheral side of the armature 22, as shown in FIGS. 1 and 2, two first magnets 27 and two second magnets 28 forming a four-pole field pole are provided via a retainer 29. Are evenly spaced.
Further, the first magnet 27 and the second magnet 28 are arranged while maintaining a predetermined positional relationship with the brushes 21 and the armature 22. Here, the predetermined positional relationship means the axis C of the armature 22 as shown in FIG.
The brush 21 is sandwiched by the plane P that is orthogonal to the bisector of the angle (90 degrees in this example) formed by the two line segments connecting a and the center Cb of each brush 21 and that includes the plane P including the axis Ca of the armature 22. The second magnet 28 is included in the space on the opposite side, and as shown in FIG. 1, the axial center 27a of the first magnet 27 is axially different from the axial center 222a of the core 222 of the armature 22. It is arranged so as to substantially match, and the second
The axial center 28a of the magnet 28 of the
The second core 222 has a positional relationship in which it is displaced from the axial center 222a of the second core 222 by a length D in the same direction as the direction of the first pressing force Fb (downward in FIG. 1).
The axial centers 27a, 28a, 222a mean positions (or points) corresponding to intermediate positions of axial lengths of the first and second magnets 27, 28 and the core 222.

Next, the force exerted by the first magnet 27 and the second magnet 28 on the core 222 of the armature 22 will be described.

First, let us consider the amount of leakage magnetic flux between the first magnet 27 and the second magnet 28 and the core 222 of the armature 22. FIG. 3 is a schematic diagram illustrating the amount of leakage magnetic flux between the core 222 and the first magnet 27 and the second magnet 28. In FIG.
It is shown that the more lines representing the leakage magnetic flux M, the greater the amount of leakage magnetic flux. Since the centers 27a and 222a of the first magnet 27 and the core 222 in the axial direction substantially coincide with each other, as shown in FIG. The axial force of 27 on the core 222 is almost zero. On the other hand, the axial center 28a of the second magnet 28
Is the axial center 222a of the core 222 of the armature 22.
On the other hand, since the first pressing force Fb and the first pressing force Fb are displaced in the same direction (downward in FIG. 1) by the length D, the leakage magnetic flux amounts at both axial ends are non-uniform. That is, as shown in FIG. 3, the amount of leakage flux at the lower end of the core 222 is larger than the amount of leakage flux at the upper end. As a result, the second magnet 28 causes the downward pulling force Fm of FIG. 3 to act on the core 222, as shown in FIG. Due to this tensile force Fm, a clockwise rotation moment Mm is generated in the armature 22 around its center of gravity CG, as shown in FIG. Here, the displacement length D between the axial center 28a of the second magnet 28 and the axial center 222a of the core 222 of the armature 22 is determined by the rotational moment Mm acting on the armature 22 by the second magnet 28 for each brush. The rotation moment Mb acting on the armature 22 is set by 21 so that the directions thereof are opposite to each other and equal in magnitude, that is, the combined moment of the rotation moments Mb and Mm becomes zero. As a result, the moment that tilts the axis of the armature 22 with respect to the axes of the bearings 23 and 24 disappears, so that it is possible to prevent the shaft 223 of the armature 22 from tilting, and as a result, during operation of the motor 2. Vibration can be suppressed and vibration of the fuel pump 1 can be suppressed.

In the fuel pump 1 according to the first embodiment of the present invention described above, the shaft 223 receives the first pressing force Fb from the brush 21, and the shaft 223 receives the two bearings 2.
The second magnet 28 is provided as the inclination suppressing means for suppressing the inclination with respect to the axis lines of 3 and 24. That is, the second magnet 28 is placed on a plane P orthogonal to the bisector of the angle formed by the line segment connecting the axis Ca of the armature 22 and the center Cb of each brush 21 and including the axis Ca of the armature 22. The axial center 28 of the second magnet 28 is placed in the space on the side facing the brushes 21.
a is the axial center 222 of the core 222 of the armature 22.
It is arranged so as to be displaced by a length D in the same direction as the direction of the first pressing force Fb with respect to a. As shown in FIG. 3, the second magnet 28 causes the downward pulling force Fm of FIG. 3 to act on the armature 22, and the pulling force Fm causes the armature 22 to generate a clockwise rotational moment Mm about its center of gravity CG. Raised. The rotation moment Mm is the rotation moment M acting on the armature 22 by each brush 21.
Since the direction is opposite to b and the magnitude is the same, the combined moment of the rotation moments Mb and Mm becomes zero. Therefore, it is possible to prevent the axis of the shaft 223 of the armature 22 from inclining with respect to the axes of the bearings 23 and 24, and as a result, suppress the vibration of the motor 2 during operation and suppress the vibration of the fuel pump 1. You can

Further, by adopting an easy means for optimally selecting the axial mounting position of the second magnet 28, it is possible to suppress the vibration of the fuel pump 1 while suppressing the cost increase to the necessary minimum.

Next, a first modified example of the fuel pump 1 according to the first embodiment of the present invention will be described.

FIG. 4 shows a cross-sectional view of the fuel pump 1 according to the first modification of the first embodiment. FIG. 4 shows the first
2 in the embodiment of FIG.

In this first modified example, the positional relationship between the brush 21, the first magnet 27 and the second magnet 28 in the fuel pump 1 according to the first embodiment is shown in FIG. It has been changed to. That is, the axis Ca of the armature 22 and the center C of each brush 21
Included in the space on the side facing the brush 21 across the plane P that is orthogonal to the bisector of the angle (90 degrees in this example) formed by the two line segments connecting with b and that includes the axis Ca of the armature 22. The number of the second magnets 28 to be used is one. First
Also in the modified example, as in the case of the first embodiment, the second
The axial center 28a of the magnet 28 of the armature 2
The two cores 222 are arranged so as to be displaced from the axial center 222a by a length D in the same direction as the first pressing force Fb.
As a result, similarly to the case of the first embodiment, it is possible to prevent the axis of the shaft 223 of the armature 22 from inclining with respect to the axes of the bearings 23 and 24, and as a result, the vibration of the motor 2 during operation is reduced. By suppressing the vibration, the vibration of the fuel pump 1 can be suppressed.

Next, a second modified example of the fuel pump 1 according to the first embodiment of the present invention will be described.

FIG. 5 is a vertical cross-sectional view of the fuel pump 1 according to the second modification of the first embodiment. In FIG.
The cross-sectional view of the fuel pump 1 by the 2nd modification of embodiment of that is, ie, the IV-IV sectional view taken on the line of FIG. Further, FIG. 7 shows the first magnet 27 and the second magnet 27 in the fuel pump 1 according to the first modification of the first embodiment.
7 is a schematic diagram illustrating the amount of leakage magnetic flux between the magnet 28 and the core 222 of FIG.

In the second modification, the positions of the first magnet 27 and the second magnet 28 are exchanged with respect to the fuel pump 1 according to the first embodiment, as shown in FIGS. 5 and 6. And the axial center 28a of the second magnet 28 as shown in FIG.
The armature 22 is disposed so as to be displaced from the axial center 222a of the core 222 of the core 222 by a length D in a direction opposite to the direction of the first pressing force Fb. As a result, as shown in FIG.
A tensile force Fm is applied to the core 222 by the second magnet 28, and a clockwise rotational moment Mm is generated around the center of gravity CG of the armature 22 by this tensile force Fm. Also in this second modified example, as in the case of the first embodiment, the displacement length D between the axial center 28a of the second magnet 28 and the axial center 222a of the core 222 of the armature 22 is optimized. The combined moment of the rotational moment Mb of the first pressing force Fb of the brush 21 and the rotational moment Mm of the second magnet 28 is zero. Therefore, as in the case of the first embodiment, it is possible to prevent the axis line of the shaft 223 of the armature 22 from inclining with respect to the axis lines of the bearings 23 and 24, and as a result, suppress vibration during operation of the motor 2. Thus, the vibration of the fuel pump 1 can be suppressed.

FIG. 8 shows a cross-sectional view of a third modification of the fuel pump 1 according to the first embodiment. In the third modification, as shown in FIG. 8, the position of the second magnet 28 of the motor 2 with respect to the fuel pump 1 according to the first modification of the first embodiment described above is changed to the first embodiment. In the same manner as in the case of the second modified example of the first embodiment described above, the axial center 28a of the second magnet 28 is changed to the axially symmetric position of the core 222. The first pressing force Fb is displaced from the axial center 222a by a length D in a direction opposite to the first pressing force Fb. As a result, as shown in FIG.
A tensile force Fm is applied to 2, and a clockwise rotational moment Mm is generated around the center of gravity CG of the armature 22 by this tensile force Fm. Also in this second modified example, the first
As in the case of the above embodiment, the shift length D between the axial center 28a of the second magnet 28 and the axial center 222a of the core 222 of the armature 22 is optimized, and the brush 21
The combined moment of the rotation moment Mb by the first pressing force Fb and the rotation moment Mm by the second magnet 28 is zero. Therefore, as in the case of the first embodiment, it is possible to prevent the axis line of the shaft 223 of the armature 22 from inclining with respect to the axis lines of the bearings 23 and 24, and as a result, suppress vibration during operation of the motor 2. Thus, the vibration of the fuel pump 1 can be suppressed.

(Second Embodiment) Next, a fuel pump 1 according to a second embodiment of the present invention will be described.

FIG. 9 is a vertical sectional view of the fuel pump 1 according to the second embodiment of the present invention. Further, FIG. 10 shows a cross-sectional view taken along line XX in FIG. 9.

In the second embodiment, as a tilt restraining means for restraining the shaft 223 from tilting with respect to the axes of the bearings 23 and 24 by receiving the first pressing force Fb from the brush 21, FIG. As shown in FIGS. 9 and 10, a pressing member 41 arranged parallel to the axis of the armature 22,
A spring 42, which is a second urging means for urging the pressing member 41 in the axial direction of the armature 22, is provided. Further, the pressing member 41, as shown in FIG.
1 is substantially axisymmetric to 1, and is orthogonal to the bisector of the angle formed by the line segment connecting the axis Ca of the armature 22 and the center Cb of each brush 21 of the commutator 221 and the axis of the armature. The portion facing the brush 21 across the straight line L passing through the core Ca is configured to be pressed by the second pressing force Fs by the spring 42.

The pressing member 41 is made of a material having excellent slidability with the commutator 221, that is, a material having a small amount of wear and a small sliding friction coefficient when contacting and sliding with the commutator 221. For example, it is formed of a resin material or the like. The pressing member 41 is used for the brush holder 12
It is accommodated in the guide portion 12b provided in the above so as to be movable in the axial direction, and contacts the commutator 221 with the second pressing force Fs by the spring 42.

Here, the rotational moment acting around the center of gravity CG of the armature 22 will be described. First, by the first pressing force Fb of each brush 21, a counterclockwise rotation moment Mb is applied to the armature 22 around its center of gravity CG, as shown in FIG. On the other hand, by the second pressing force Fs by each pressing member 41,
As shown in FIG. 9, the armature 22 has its center of gravity CG.
A clockwise rotation moment Ms acts on the circumference. Here, the specifications of the spring 42 are set so that the two rotation moments Ms and Mb have opposite directions and equal magnitudes. Therefore, the combined moment of the two rotation moments Ms and Mb becomes 0, so that it is possible to prevent the axis line of the shaft 223 of the armature 22 from inclining with respect to the axis lines of the bearings 23 and 24, and as a result, the operation of the motor 2 is performed. Vibration inside the fuel pump 1 can be suppressed to suppress vibration of the fuel pump 1.

Next, a modification of the fuel pump 1 according to the second embodiment of the present invention will be described.

FIG. 11 is a vertical sectional view of the fuel pump 1 according to the modified example of the second embodiment.

In this modification, the mounting position of the pressing member 41 and the position where the pressing member 41 abuts on the armature 22 are changed with respect to the fuel pump 1 according to the second embodiment. That is, the axis of the armature 22 is orthogonal to the bisector of the angle (90 degrees in this example) formed by the two line segments connecting the axis Ca of the armature 22 and the center Cb of each brush 21 in FIG. While arranging the pressing member 41 in the space on the brush 21 side of the plane P containing Ca,
The pressing member 41 is pressed into contact with the end surface 22a of the armature 22 opposite to the commutator 221. Also, the pressing member 4
Two 1 are provided to face each brush 21 and the armature 22 in the axial direction.

As shown in FIG. 11, the pressing member 41 is accommodated in a guide portion 33a provided in the pump casing 33 so as to be movable in the axial direction, and a second member formed by a spring 42.
The end face 22a of the armature 22 is in contact with the pressing force Fs. The second pressing force Fs acts on the armature 22 in a direction opposite to the direction of the first pressing force Fb of each brush 21.

Here, the rotation moment acting around the center of gravity CG of the armature 22 will be described. First, by the first pressing force Fb of each brush 21, a counterclockwise rotation moment Mb acts on the armature 22 around its center of gravity CG, as shown in FIG. On the other hand, by the second pressing force Fs by each pressing member 41,
The armature 22 has its center of gravity C as shown in FIG.
A clockwise rotation moment Ms acts around G. Here, the specifications of the spring 42 are set so that the two rotation moments Ms and Mb have opposite directions and equal magnitudes. Therefore, the combined moment of the two rotation moments Ms and Mb becomes 0, so that it is possible to prevent the axis line of the shaft 223 of the armature 22 from inclining with respect to the axis lines of the bearings 23 and 24, and as a result, the operation of the motor 2 is performed. Vibration inside the fuel pump 1 can be suppressed to suppress vibration of the fuel pump 1.

In this modification, the pressing member 4
1 is an end face 2 formed from the resin 224 of the armature 22.
Although it is in direct contact with 2a, another disc-shaped member (not shown) having excellent slidability with the pressing member 41 (low wear and low friction coefficient) is fixed to the end surface 22a, and the pressing member is attached thereto. 41 may be contacted.

In the above-described second embodiment of the present invention and its modification, the number of pressing members 41 is two, but it may be a number other than two. For example, the number may be one or three. The two rotation moments Ms and Mb in FIG. 11 are the same as in the case of the second embodiment of the present invention and its modification, if the specifications of the spring 42 are set such that the directions are opposite to each other and the magnitudes thereof are equal. The effect of is obtained.

Further, in the above-described second embodiment of the present invention and its modification, the brush 21 of the motor 2 is used.
And the first magnet 27 and the second magnet 2
The positional relationship with 8 may be as shown in FIG.

(Third Embodiment) Next, a fuel pump 1 according to a third embodiment of the present invention will be described.

FIG. 12 is a vertical sectional view of the fuel pump 1 according to the third embodiment of the present invention.

The third embodiment is a modification of the shapes and configurations of the shaft 223 and the bearings 23, 24 of the fuel pump 1 according to the first embodiment of the present invention.

The shaft 50 has a hollow cylindrical shape. That is, as shown in FIG. 12, after the pipe 51 is press-fitted and fixed to the core 222, the sleeves 52 and 53 are press-fitted and fixed to both ends of the pipe 51.

The sleeve 5 which is the inner diameter of the shaft 50
The inner diameter portions 52a and 53a of the two and 53 are rotatably fitted to the outer diameter portion 54a of the bearing 54. That is, the motor 2
The shaft 50 of the armature 22 is rotatably supported by bearings 54 in the radial direction. Further, the impeller 32 is axially slidably fitted to the outer circumference of the sleeve 52 arranged on the pump 3 side (downward in FIG. 12), and the armature 22
Is engaged with the protrusion 222a. In other words, impeller 3
2 rotates integrally with the shaft 50. Further, the sleeve 52 is in contact with the thrust bearing 25 at its end portion, and supports the load in the thrust direction (downward in FIG. 1).
Here, the pipe 51 is formed of a steel pipe or the like, and the bearing 54
Is made of steel pipe or steel rod. On the other hand, the sleeves 52 and 53 are formed of a material having excellent slidability with the bearing 54 (low wear and low friction coefficient), such as gun metal.

The first magnet 27 and the second magnet 28 are arranged in the same positional relationship with the core 222 of the armature 22 as in the case of the first embodiment of the present invention. Therefore, also in the fuel pump 1 according to the third embodiment, the same effect as in the case of the first embodiment can be obtained. That is, it is possible to prevent the axis of the shaft 50 of the armature 22 from inclining with respect to the axis of the bearing 54, and as a result, it is possible to suppress vibration during operation of the motor 2 and suppress vibration of the fuel pump 1.

Further, by making the shaft 50 a hollow cylinder, the weight of the fuel pump 1 can be reduced.

In the above-described first embodiment of the present invention and its first to third modifications, the second embodiment of the present invention and its modifications, and the third embodiment, the configuration of the motor 2 will be described. Although it is a concentrated winding type with 4 poles and 6 slots,
The same applies to the other types of motors such as the 8-pole 12-slot concentrated winding type as long as the brushes 21 are arranged in a non-axisymmetric manner with respect to the shaft 223 or the shaft 50. By configuring,
The same effect can be obtained.

Further, the field magnet structure in the first modification of the first embodiment described above, that is, the number of the first magnets 27 is 3 and the number of the second magnets 28 is 1 It may be applied to the fuel pump 1 according to the first embodiment. In this case, the counterclockwise rotation moment Mb acting around the center of gravity CG of the armature 22 can be canceled to some extent by the first pressing force Fb of each brush 21, and the first embodiment and the first embodiment can be used.
In the fuel pump 1 according to the first modified example of the embodiment described above, it is possible to achieve cost reduction by realizing common parts with the same field magnet configuration.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a fuel pump 1 according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG.

FIG. 3 is a schematic diagram illustrating a leakage magnetic flux amount between a core 222 and a first magnet 27 and a second magnet 28 according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of a fuel pump 1 according to a first modified example of the first embodiment of the present invention.

FIG. 5 is a vertical sectional view of a fuel pump 1 according to a second modified example of the first embodiment of the present invention.

FIG. 6 is a transverse sectional view of a fuel pump 1 according to a second modified example of the first embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a leakage magnetic flux amount between the core 222 and the first magnet 27 and the second magnet 28 of the fuel pump 1 according to the second modified example of the first embodiment of the present invention. .

FIG. 8 is a cross-sectional view of a fuel pump 1 according to a third modified example of the first embodiment of the present invention.

FIG. 9 is a vertical sectional view of a fuel pump 1 according to a second embodiment of the present invention.

10 is a cross-sectional view taken along line XX of FIG.

FIG. 11 is a sectional view of a fuel pump 1 according to a modified example of the second embodiment of the present invention.

FIG. 12 is a sectional view of a fuel pump 1 according to a modification of the third embodiment of the present invention.

[Explanation of symbols]

1 Fuel pump (fuel pump for vehicles) 2 motors (vehicle electric motors) 3 Eddy current pump 21 brush 22 Armature 23 Spherical bearing (bearing) 24 Plane bearings (bearings) 26 Brush Spring (First Biasing Means) 27 First Magnet 28 Second magnet (inclination suppressing means) 28a center line 33 Pump casing 41 Pressing member 42 spring (second urging means) 50 shaft 51 pipes 52, 53 Sleeve 54 bearing 221 commutator 222 core 222a center line 223 shaft D length

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F04D 13/08 F04D 13/08 U 29/00 29/00 B H02K 23/00 H02K 23/00 A F term (Reference) 3H022 AA01 BA03 CA06 CA50 DA11 5H605 BB05 CC04 CC05 DD09 DD35 EB06 EB39 EC05 5H623 BB07 GG13 GG23 JJ06 LL07 LL14

Claims (8)

[Claims] 1. An armature having a shaft and a disc-shaped commutator at one end thereof, a plurality of first magnets arranged at equal angular intervals on the outer peripheral side of the armature, and parallel to the axis of the armature. A pair of disposed brushes; a first biasing unit that biases the brush with a first pressing force parallel to the axis of the armature to bring the brush into axial contact with the commutator; A bearing for rotatably holding the shaft, wherein the brush is arranged non-axisymmetrically with respect to the shaft, wherein the shaft is inclined with respect to the axis of the bearing by the first pressing force. An electric motor for a vehicle, comprising: an inclination suppressing means for suppressing the above. 2. The tilt suppressing means comprises a pressing member arranged in parallel with an axis of the armature, and a second pressing member for urging the pressing member in an axial direction of the armature.
The pressing member is orthogonal to the bisector of the angle formed by the line segment connecting the axis of the armature and the center of each brush in the commutator, and the axis of the armature. 2. The electric motor for a vehicle according to claim 1, wherein a portion facing the brush across a straight line passing through the core is pressed by a second pressing force of the second biasing means. 3. The pressing member is orthogonal to a bisector of an angle formed by a line segment connecting an axial center of the armature and a center of each of the brushes on the other end side end face of the armature, and the pressing member of the armature. The electric motor for a vehicle according to claim 2, wherein a portion of the plane including the shaft center, which is included in the space on the brush side, is pressed by the second pressing force of the second biasing means. 4. As the inclination suppressing means, a part of the first magnet is constituted as a second magnet, and the second magnet connects a line connecting an axis of the armature and a center of each brush. It is included in a space that is orthogonal to the bisector of the angle formed by the parts and that faces the brush across a plane that includes the axis of the armature, and the axial center of the first magnet is the center of the armature. The axial center of the second magnet is disposed substantially in the axial direction of the core, and the axial center of the second magnet is in the same direction as the first pressing force with respect to the axial center of the core of the armature. The vehicle electric motor according to claim 1, wherein the electric motors are arranged in a staggered manner. 5. The second magnet has a plane perpendicular to a bisector of an angle formed by a line segment connecting the axis of the armature and the center of each of the brushes and including the axis of the armature. It is included in the space on the brush side, and the axial center of the second magnet is arranged so as to be offset from the axial center of the core of the armature in a direction opposite to the direction of the first pressing force. The electric motor for vehicle according to claim 4. 6. The electric motor for a vehicle according to claim 1, wherein the armature has six salient poles radially and the number of the magnets is four. 7. The shaft is formed in a hollow cylindrical shape, and the inner diameter portion of the shaft is rotatably fitted to the outer diameter portion of the bearing.
7. The electric motor for a vehicle according to claim 6. 8. The vehicle according to any one of claims 1 to 7, wherein the vehicle is driven by the vehicle electric motor, which is applied to a vehicle fuel pump driving electric motor. Electric motor.