JPH04200253A - vehicle fuel pump - Google Patents

Abstract

PURPOSE:To suppress the rocking of the rotary shaft inside the bearings by enlarging the space between the facing ends of permanent magnets on one side in circumferential direction compared with that on the other side in circumferential direction. CONSTITUTION:An armature 13 seeks to shift downward inside the housing, being attracted toward the other ends 20B and 21B of permanent magnets 20 and 21. At this time, the rotary shaft 12 including the armature 13 and the commutator 14 is pressed toward the bottom sides inside the bearings 5 and 11 by strong magnetic attraction toward the ends 20B and 21B on the other side of the permanent magnets 20 and 21, so the rotary shaft 12 rotates in the condition of being pressed to the bottom side inside the bearings 5 and 11, without being rocked by this pressure.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a fuel pump in which a pump part is driven by a rotational force output from a motor part to perform a pumping action, and is suitable for use in vehicles such as two-wheeled vehicles and four-wheeled vehicles. Regarding the vehicle fuel pump installed.

[Conventional technology]

A fuel pump for a vehicle (hereinafter referred to as a fuel pump) conventionally used in fuel pumps will be explained with reference to FIGS. 2 and 3. FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 is a longitudinal sectional view taken along the line ■-■ in FIG.

The fuel pump is composed of a motor section M and a pump section P. Reference numeral 1 denotes a cylindrical housing made of a magnetic material such as iron, both ends of which are open, and stepped portions IA are formed on the inner peripheral surface of the housing 1 near each open end.

The opening of the housing l is closed by a bearing holder 2 and a pump casing 3, and these bearing holder 2 and pump casing 3 are fixedly arranged on the stepped portion IA of the housing 1 to close the opening. do. The bearing holder 2 is formed with a fuel flow path 4 whose negative side (left side in FIG. 2) opens with a recess into the housing 1 and whose other side opens to the outside via a fuel outflow path F. A bearing 5 is fixedly arranged in the channel 4 via a retainer 6. The bearing 5 is disposed at the center of the housing 1, and the retainer 6 is further provided with a communication hole 7 that communicates the fuel flow path 4 divided by the retainer 6.

A pump cover 8 is disposed opposite to each other on the outward end surface of the pump casing 3, and the opening on the left side of the housing 1 is substantially closed by the pump casing 3 and the pump cover 8.

An annular recess 3A formed in the end surface near the outer periphery of the pump casing 3 and an annular recess 8A formed in the end surface near the outer periphery of the pump cover 8 opposite to the end surface of the pump casing 3 form an annular shape. A pump channel 9 is formed, and a fuel suction channel 10 provided in the pump cover 8 opens into this pump channel 9, and a fuel discharge channel (not shown) provided in the pump casing 3 opens therein. This fuel discharge passage communicates into the housing 1.

Further, a bearing 11 is fixedly disposed in the pump casing 3, and this bearing 11 is disposed at the center of the housing 1.

A rotary shaft 12 is rotatably supported by bearings 5 and 11 arranged in the bearing holder 2 and the pump casing 3. reaches the recess 8A.

Thus, the rotating shaft 12 forms a concentric relationship with the housing l.

The rotating shaft 12 has an armature 13 made of a laminated steel plate 13A made by stacking a plurality of plate-shaped steel plates with a plurality of slit grooves, and a coil wire wound around the slit grooves of the laminated steel plate. A commutator 14 is fixedly arranged and connected to the coil wire.

The armature 13 and the commutator 14 are in a concentric relationship with the housing 1, and the commutator 14 is in sliding contact with a pair of brushes 15 that are symmetrically arranged opposite to each other, and the brushes 15 are connected to a power source. (Slit groove of laminated steel plate 13A, coil wire, pair of brushes 1
5 and the power source are not shown.) 16.17 is a pair of cylinders arranged on the inner periphery of the housing 1 in a concentric relationship with the housing 1 and symmetrically arranged opposite to each other. It is a permanent magnet of the shape, and the permanent magnet 16
．． A minute gap is formed between the inner peripheral surface of the armature 17 and the outer peripheral surface of the armature 13.

The state in which the pair of permanent magnets 16 and 17 are arranged symmetrically and facing each other in the housing 1 is shown in FIG.
More specifically, one end 16A in the circumferential direction of one permanent magnet 16 and one end 17A in the circumferential direction of the other permanent magnet 17 face each other in the circumferential direction, and there is a gap between them in the circumferential direction. γ, and further, the other end 16B of one permanent magnet 16 in the circumferential direction and the other end 17B of the other permanent magnet 17 in the circumferential direction are opposite to each other in the circumferential direction, and are opposite to each other in the circumferential direction. Gap γ
form.

One permanent magnet 16 and the other permanent magnet 17 are arranged in the housing 1 so that the negative side facing gap γ and the other side facing gap γ are approximately equal. Magnet 16.17, armature 13
, the commutator 14, and the rotating shaft 12 are in a concentric relationship, and the motor section M is mainly formed by the above configuration.

The rotating shaft 12 located within the recess 8A of the pump cover 8
A disc-shaped impeller 17 is integrally disposed at the end of the impeller 17, and a blade groove 17A is formed over the entire circumference at the outer peripheral end of the impeller 17 facing the pump flow path 9. The impeller 17, the blade groove l7A, and the pump channel 9 form a pump portion P.

As a result, the rotating shaft 1 is turned on by energizing the motor section M.
2 rotates, the pump part P is driven and the fuel suction passage 10 is rotated.
It absorbs more fuel and discharges the fuel from the fuel outflow path F.

This fuel pump is disclosed, for example, in Japanese Patent Laid-Open No. 60-79193.

In such a conventional fuel pump, there is a small gap (for example, 2 mm) between the inner diameter of the bearings 5 and 11 and the outer diameter of the rotating shaft 12.
0IL) is formed. This connects the rotating shaft 12 to the bearing 5.
, 11 for rotatable support.

On the other hand, the rotating shaft 12 including the armature 13 and commutator 14 must be accurately balanced in the rotational direction. This means that when the rotating shaft 12 rotates,
Bearing 5. If the 0-rotation shaft 12 is not accurately balanced, which is necessary to prevent the rotation shaft 12 from swinging (center runout of the rotary shaft 12) within the bearings 5 and 11, the rotation shaft 12 may This causes the rotation shaft 12 and the bearings 5, 1 to
(2) They collide irregularly and produce a hitting sound, which is undesirable because it disturbs the driver's sense of riding, especially when installed in a vehicle.

On the other hand, there has been a trend towards smaller fuel pumps in recent years. This is achieved by making the fuel pump smaller and lighter.
This is necessary to reduce the overall weight of the vehicle and improve fuel economy, as well as to increase the degree of freedom in mounting the fuel pump on the fuel tank.

[Problem to be solved by the invention]

Under such circumstances, in order to downsize the fuel pump, it is effective to reduce the outer diameter of the housing, and it is necessary to reduce the outer diameter of the impeller in the pump section inside the housing. By reducing the outer diameter of the impeller, the circumferential speed of the blade grooves on the outer periphery of the impeller decreases, and the amount of fuel discharged from the fuel pump tends to decrease. (Here, the amount of fuel discharged by the fuel pump is determined by the engine in which it is installed, and the amount of fuel discharged must not decrease due to downsizing of the fuel pump.) In order to prevent this decrease in the amount of fuel discharged, It is necessary to increase the rotation speed of the motor section. For example, when the armature has an outer diameter of φ30mm and is 400 ORPM, when it is downsized to an armature with an outer diameter of φ25, the speed is 8000RPM.
raise it to.

Since the rotational speed of the motor section has been greatly increased in this manner, the balance of the rotating shaft including the armature, the turret, and the commutator must be carried out with much higher precision than in the past. For example, armature outer diameter φ30
The surface unbalance regulation value of the armature at the time of ORPM was balanced at 90mar, but it became 80mm at the armature outer diameter φ25mm.
00 RPM, it is necessary to control the armature surface unbalance regulation value at 10 mmgr. In this way, it is necessary to balance the rotating shaft including the armature and commutator with extremely high precision, which is why balancer machines are used as machine tools for balancing, or fixed position stopping devices for detection are used as action balancers. It is necessary to prepare testing machines, and these devices are extremely expensive as control accuracy improves.
Furthermore, this is not preferable because it increases the number of man-hours for processing and inspection, which increases the manufacturing cost of the fuel pump.

The vehicle fuel pump of the present invention was created in view of the above-mentioned problems, and when downsizing the fuel pump, there is no need to maintain and manage the balance of the rotating shaft including the armature and commutator with extremely high precision. It is an object of the present invention to provide the fuel pump that is inexpensive to manufacture.

[Means to solve problems]

In order to achieve the above object, the vehicle fuel pump of the present invention includes: a rotating shaft rotatably supported by a bearing integrally attached to the housing in a concentric relationship with the housing; a pair of cylindrical permanent magnets arranged symmetrically and facing each other in a housing in a concentric relationship; an armature integrally attached to a rotating shaft in a concentric relationship with the permanent magnets; A motor section formed by a commutator integrally attached to a shaft and connected to an armature, and a brush in sliding contact with the commutator: A pump that performs a pumping action by rotation of a rotating shaft of the motor section. and; in a vehicle fuel pump that is provided in a housing, one side in the circumferential direction formed by one end in the circumferential direction of one permanent magnet and one end in the circumferential direction of the other permanent magnet. The facing gap α is made larger than the other facing gap β in the circumferential direction formed by the other end in the circumferential direction of one permanent magnet and the other end in the circumferential direction of the other permanent magnet. .

[Effect]

According to this configuration, since the magnetic force on the smaller side of the facing gap where the ends of each permanent magnet face each other becomes stronger, the armature is constantly attracted and rotates toward the smaller side of the facing gap, so that the armature is integrated with the armature. The rotating shaft attached to the bearing is also located within the bearing and rotates while being pressed to one side at all times, thereby suppressing the swinging of the rotating shaft within the bearing.

Therefore, there is no need to maintain or manage extremely high balancing accuracy of the rotating shaft including the armature and commutator.

[Embodiment] Hereinafter, an embodiment of the fuel pump according to the present invention will be described with reference to FIG.

Figure 1 shows a vertical cross-sectional view of the main parts of the fuel pump.
It shows a longitudinal section at the same position as the line mm in FIG. 2. still,
In FIG. 1, the slit grooves of the eight-layer steel plate constituting the armature and the coil wires are not shown. Further, the same structures as those in the prior art are denoted by the same reference numerals as in FIG. 2, and the explanation thereof will be omitted.

20.21 are 1 arranged oppositely in the housing 1.
A pair of cylindrical permanent magnets, one permanent magnet 20 and the other permanent magnet 21 have the same shape, and the housing 1
, the armature 13 and the rotating shaft load 2 are arranged in a concentric relationship.

The front water distribution magnets 20 and 21 are arranged in the housing 1 as follows.

That is, between the respective one side ends 20A and 21A formed by the one side end 20A in the circumferential direction of one permanent magnet 20 and the one side end 21A in the circumferential direction of the other permanent magnet 21 opposing thereto. One side facing gap α is defined as the other side end 20B in the circumferential direction of one permanent magnet 20.
and the other side end 21-B in the circumferential direction of the other permanent magnet 21 facing thereto.

This can be achieved by moving one permanent magnet 16 in the state shown in FIG. 3 by a certain angle clockwise and moving the other permanent magnet 17 by a certain angle counterclockwise.

As described above, by arranging the pair of permanent magnets 20 and 21 in the housing l, the magnetic flux is transmitted through the vicinity of the other end 20B of one permanent magnet 20 and the other end 21B of the other permanent magnet 21. The magnetic flux density acting on the armature 13 is
Since the magnetic flux density is denser than the magnetic flux density that acts on the armature 13 through the vicinity of the one side end 21A, the magnetic flux that acts on the armature 13 from the vicinity of the other side ends 20B and 21B of each permanent magnet 20.21 The suction force is - side end 20A,
From the vicinity of 21B, the magnetic attraction force becomes larger compared to the acting magnetic attraction force.

Therefore, the armature 13 is attracted toward the other end portions 20B, 21B of each permanent magnet 20.degree. 21, and tends to move downward within the housing 1 in FIG.

According to the downward movement of the armature 13, the rotating shaft 12 formed integrally with the armature 13 also moves downward in synchronization, and the rotating shaft 12 is moved downward by the bearings 5 and 11.
It is held pressed against the lower surface of the inside. At this time, the outer surface 13B of the armature 13 does not come into contact with the inner surface of the permanent magnet.

When the motor section M is energized in such a state, the armature 13, commutator 14 . The rotating shaft 12 including the armature 13 and the commutator 14 starts to rotate.At this time, if the balancing accuracy of the rotating shaft 12 including the armature 13 and commutator 14 is not adjusted with extremely high precision, (the surface of the armature With the unbalance regulation value controlled at about 90 mBr,
.

RPM ), the rotating shaft 12 begins to swing.

However, the rotating shaft 12 including the armature 13 and the commutator 14 is located at the other end 20B of each permanent magnet 20.21.
, bearing 5 receives strong magnetic attraction toward the 21B side.
Since the rotating shaft 12 is pressed against the lower surface inside the bearing 5.11, the rotating shaft 12 rotates while being pressed against the lower surface inside the bearing 5.11 without swinging due to this pressing force.

Therefore, the bearings 5, 11 and the rotating shaft 12 do not collide irregularly and generate hammering sounds.

In addition, the other end 20B of each permanent magnet 20.21.

The magnetic attraction force near 21B resists the rocking of the rotating shaft 12 when the rotating shaft 12 rotates at high speed, and causes the rotating shaft 12 to move toward the bearing 5.
, 11 with sufficient force to press and hold them against one side. This can be achieved by appropriately setting the opposing gap β on the other side.

〔Effect of the invention〕

As described above, according to the vehicle fuel pump of the present invention,
A rotating shaft that is rotatably supported in a bearing integrally attached to the housing in a concentric relationship with the housing; A pair of cylindrical permanent magnets, an armature that is concentric with the permanent magnets and integrally attached to the rotating shaft, and a commutator that is integrally attached to the rotating shaft and connected to the armature. .

A vehicular fuel pump comprising, in a housing, a motor section formed by a brush that is in sliding contact with a commutator; and a pump section that performs a pumping action by rotation of a rotating shaft of the motor section; One side facing gap α in the circumferential direction formed by one side end in the circumferential direction of one permanent magnet and one side end in the circumferential direction of the other permanent magnet is defined as the other side end in the circumferential direction of one permanent magnet. and the other end of the other permanent magnet in the circumferential direction, so that the rotating shaft including the armature has an opposing gap smaller than the - side opposing gap α. The rotary shaft is attracted to the vicinity of the other end of each permanent magnet on the other side facing gap β side, and the rotating shaft is held in a state where it is pressed against one of the bearings.

Therefore, the balance of the rotating shaft can be maintained with extremely high precision.
Even if the rotating shaft is not controlled, the rotating shaft is pressed in one direction, so the rotating shaft does not swing (runout) within the bearing. According to this, when the rotating shaft swings, the rotating shaft and the bearing It is possible to provide an extremely quiet fuel pump that does not produce hitting sounds due to irregular collisions between the fuel pumps and the fuel pumps, and is particularly suitable for use in vehicles where quietness is desired.

In addition, there is no need to maintain or manage the balance of the rotating shaft with extremely high precision (the same level of management as before is sufficient).
In particular, there was no need to invest in expensive machine tools for cleaning or testing machines for detection, which made it possible to reduce the manufacturing cost of the fuel pump.

Furthermore, increases in processing and inspection time due to improved control accuracy can be suppressed.

Furthermore, when arranging a conventionally used pair of permanent magnets of the same shape in the housing, only the arrangement needs to be changed, so there is no need to change any parts for implementation.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of a vehicle fuel pump according to the present invention, and is a longitudinal sectional view taken at a position corresponding to the line m--■ in FIG. FIG. 2 is a vertical cross-sectional view of a main part of a conventional fuel pump, and FIG. 3 is a vertical cross-sectional view taken along the line m--■ in FIG. 1... Housing 5, 11... Bearing 12
... Rotating shaft 13 ... Armature 14
Commutator 20... One permanent magnet 20A... - side end 2
0B...Other side end 21...Other permanent magnet 21A...-side end 2
1B...Other side end α...-side opposing gap β・
...Gap agent facing the other side Patent attorney Ike 1) Hiroshi Figure 3 α Figure 1

Claims (1)

[Scope of Claims] A rotating shaft rotatably supported in a bearing integrally attached to the housing in a concentric relationship with the housing; a pair of cylindrical permanent magnets arranged symmetrically, an armature that is integrally attached to the rotating shaft in a concentric relationship with the permanent magnets, and an armature that is integrally attached to the rotating shaft and the armature. A motor unit formed by: a commutator connected to the commutator; a brush in sliding contact with the commutator; and a pump unit that performs a pumping action by rotation of a rotating shaft of the motor unit. In a fuel pump, one side facing gap α in the circumferential direction formed by one side end in the circumferential direction of one permanent magnet and one side end in the circumferential direction of the other permanent magnet is defined as A fuel pump for a vehicle, which is larger than a circumferential other side opposing gap β formed by the other end in the circumferential direction and the other end in the circumferential direction of the other permanent magnet.