JPS6146670B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric pump having a pump portion driven by an electric motor provided inside. The present invention relates to a fuel pump that supplies fuel, but it can also be used as an electric pump for general industrial use.

[Conventional technology]

Such an electric pump has an electric motor and a pump chamber inside, and is configured so that a rotating shaft of the electric motor drives a rotor portion in the pump chamber. In order to operate this type of pump efficiently, the pump chamber must be firmly positioned and fixed inside the pump housing, a yoke for the electric motor part must be provided inside the pump housing, and the center of the yoke must be precisely aligned. It is necessary to install a self-aligning bearing to support the rotating shaft of the electric motor.

In other words, it is required to be able to accurately position the rotating shaft on the center line of the cylindrical yoke, and to assemble an efficient self-aligning bearing that supports this rotating shaft adjacent to the pump chamber with high dimensional accuracy. be done. Moreover, in this case, a pump structure is required that has a small number of parts and allows easy control of assembly accuracy.

However, conventional pumps have not been able to fully satisfy these requirements. For example, Utility Model Application No. 51-3104 is known as a conventional pump, but in this pump, a pump body, which is a separate member from the motor housing, is interposed between the motor housing, which forms a cylindrical yoke, and the self-aligning bearing. Therefore, in order to accurately assemble the self-aligning bearing to the central axis of the motor housing, the assembly accuracy of the pump body and motor housing must be improved. Therefore, a structure is required in which the self-aligning bearing can be directly supported by the yoke, but this cannot be achieved with this known example.

In addition, fuel pumps disclosed in Japanese Patent Application Laid-open No. 48-31502 and No. 49-125901 are known, but in both of these, when positioning the bearing part at the center of the casing, the yoke part of the electric motor and the bearing part are The parts are not integrated with the same member, but are assembled by overlapping different parts and are integrated. Furthermore, neither pump has a structure that allows for the adoption of self-aligning bearings.

In addition, a pump shown in Japanese Patent Application Laid-open No. 48-65322 is also known, but in this pump as well, the self-aligning bearing adjacent to the pump chamber is not formed integrally with the yoke, and the self-aligning bearing is attached to the yoke. Accurate positioning on the central axis requires considerable assembly control precision.

[Problem that the invention seeks to solve]

The problem to be solved by the present invention is to increase the rotational efficiency of the electric motor by accurately positioning the rotating shaft in the center of the cylindrical yoke using a self-aligning bearing, and to increase the rotational efficiency of the electric motor by positioning the rotating shaft accurately at the center of the cylindrical yoke. To provide a structure in which a self-aligning bearing can be assembled and fixed on the side surface of a pump chamber with a small number of parts so that the chamber and the self-aligning bearing do not interfere with each other.

[Structure of the invention]

In order to solve the above-mentioned problems, in the present invention, the yoke 5 is press-molded integrally with the bearing holding part 7. That is, although the yoke 5 has a cylindrical outer shape, the cylindrical shape is formed by drawing a magnetic member such as iron using a press, and at the same time, the recessed bearing holding portion 7 is integrally formed by reverse drawing. It is press-molded, and the recessed bearing holding part 7 and the cylindrical yoke part are integrated with the same magnetic member.

This makes it possible to form the recessed bearing holding portion 7 accurately at the center of the cylindrical yoke 5. In other words, the dimensional accuracy in this case only needs to be the dimensional accuracy of the press mold, and is not related to errors during assembly. can be positioned. As a result, the air gap between the armature of the motor and the permanent magnet forming the field can be made extremely small, and the efficiency of the motor can be increased. In addition, since the recessed bearing holding portion 7 is formed by a reverse throttle, the self-aligning bearing can be stored in the recessed bearing holding portion 7, and the self-aligning bearing can be connected to the adjacent pump chamber. This pump chamber can be positioned and fixed by the side wall around the bearing holding part 7 that holds the self-aligning bearing without interference.

[Effect]

In order to increase the efficiency of the electric motor, it is desirable to accurately position the rotating shaft of the electric motor on the central axis of the yoke and to support the rotating shaft with a self-aligning bearing. In this case, it is desirable that the bearing holding part 7 that holds the self-aligning bearing and the yoke 5 are integrally formed of the same material.
If a separate member is interposed between the yoke 5 and the yoke 5, it becomes difficult to form the bearing holding portion 7 on the central axis of the yoke 5 due to dimensional deviation during assembly. Alternatively, care must be taken to manage dimensional accuracy during assembly. In the present invention, since the yoke 5 and the bearing holding portion 7 are integrally formed using the same magnetic material by press molding, the above-mentioned problems are eliminated. In addition, since the bearing holding part 7 is provided in the side surface of the yoke 5 in a concave shape using reverse drawing in press forming, there is no possibility that the bearing holding part 7 or the self-aligning bearing will interfere with the adjacent pump chamber. This makes it possible to assemble the pump chamber in close contact with the side surface of the yoke 5, thereby allowing the pump chamber and the yoke forming the electric motor portion to be firmly connected.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain an electric pump with a small number of parts and a high efficiency of the electric motor portion. That is, by reverse drawing the yoke, the bearing holder 7 is integrally formed on the end face of the yoke opposite to the opening using the same material as the yoke. It can be positioned accurately on the central axis, and this dimensional accuracy can be achieved simply by controlling the accuracy of the press die. Furthermore, since the bearing holding part 7 is formed as a recessed part on the side surface of the yoke, a flat surface supporting the pump chamber can be formed on the side surface of the yoke, and the flat surface on the outer peripheral part of this bearing holding part can be formed on the side surface of the yoke. The pump chamber can be tightly combined. This has the effect that it is possible to provide an electric pump that is efficient, has a small number of parts, and can tightly connect the motor section and the pump chamber section.

〔Example〕

An embodiment of the pump of the present invention will be described below with reference to the drawings. In FIGS. 1 to 3, reference numeral 1 denotes a pump housing, which has a cylindrical shape and has a suction port 2 integrally provided at its right end in the drawings and an opening 3 at its left end.

Reference numeral 4 denotes a pump chamber, and the pump chamber 4 is particularly comprised of a known roller pump. Reference numeral 5 denotes an iron yoke having a cylindrical shape, the right end 6 of which is bent toward the center and integrally has a bearing holding portion 7;
A through hole 8 is formed approximately in the center. A bearing 9 supports the right end of the rotating shaft 11 of the armature 10. 12 is a silencer (damper), which is an air bag that absorbs fluid pressure pulsations. Reference numeral 13 is a magnet serving as a field part, 14 is a brush, and 15 is a discharge-side bearing holding part that holds the brush 14 and also holds the bearing 16, and has a discharge port 17 at the left end. A seal portion 18 seals between the discharge side bearing holding portion 15 and the pump housing 1. The pump chamber 4 is fixed to the right end 6 of the yoke 5 by screws 19, and the right end 6 of the yoke 5 is provided with a burring portion 20 into which the screw 19 is screwed.

In the above configuration, fluid such as gasoline is supplied to the suction port 2.
From there, it passes through the suction hole 4a and discharge hole 4b of the pump chamber 4, passes between the bearing spring 21, and further passes through the small hole 7a provided in the bearing holding portion 7 of the yoke 5 to reach the vicinity of the armature. At this time, the bearing 9 is cooled by the fluid. Furthermore, the fluid passes through the outer circumference of the bearing 16 and enters the discharge port 1.
It reaches 7. 22 is a check valve. and rotation axis 1
Since the right end of 1 is held by the bearing 9 held by the bearing holder 7, which is a part of the yoke 5, it is easy to reliably and easily align the center of the yoke 5 and the bearing 9, and hence the right end of the rotating shaft 11. is fixed and the axis will not shift.

On the other hand, the left end of the rotating shaft 11 is the discharge side bearing holding part 1
Since the bearing 16 is positioned via the
Although the position of the bearing 16 is not as precisely determined as that of the bearing 9 at the right end, it is easy to determine the position of the rotating shaft 11 as a whole within an allowable range.

In addition, the pump chamber 4 has a yoke 5 near the bearing holding portion 7.
It can be easily and firmly attached to the yoke 5 by the burring part 20 provided at the yoke 5.

Next, regarding the sealing action, leakage of fluid to the outside of the pump can be completely prevented by simply providing the sealing part 18 on the discharge side bearing holding part 15 located at the left end of the yoke 5.

The pump housing 1 has a suction port 2 on one side and an opening 3 on the other side, and can be manufactured by molding a light metal such as aluminum using a press machine. The yoke 5 can also be formed into a cylindrical shape by molding a magnetic member such as iron using a press machine, and can also be formed by molding a part of the bearing holding portion 7 in the opposite direction. In other words, both the pump housing and the cylindrical yoke 5 can be easily formed by molding using well-known press technology. Since the cylindrical outer circumferential portion of the yoke 5 and the bearing holding portion 7 are integrally formed, the bearing holding portion can be formed precisely at the center of the cylindrical shape of the yoke 5. The rotating shaft can be positioned accurately on the shaft, improving the efficiency of the motor part and improving the characteristics of the pump. Moreover, the number of parts can be reduced by integral molding.

[Brief explanation of the drawing]

Fig. 1 is an outer diameter diagram showing a first embodiment of the pump of the present invention, Fig. 2 is a partial sectional view of the pump shown in Fig. 1, and Fig. 3 is a view taken along the arrow A-A' line shown in Fig. 2. FIG. 4 is a front view of the other end of the yoke. 1...Pump housing, 2...Suction port, 4...
...Pump chamber, 5...Yoke, 7...Bearing holding part,
8... Through hole, 9, 16... Bearing, 10... Armature, 11... Rotating shaft, 13... Field part, 15...
Discharge side bearing holding part, 17...discharge port, 18... sealing part.

Claims (1)

[Scope of Claims] 1. A cylindrical pump housing 1 having an opening on one side and integrally having a suction port 2 on the other side, which is inserted into the pump housing 1 and having an opening on one side. A yoke 5 made of a cylindrical magnetic member integrally having a through hole 8 and a recessed bearing holding portion 7 at the center of the other direction and formed by reverse drawing in a press; A flat surface of the outer circumference of the concave bearing holding portion 7 of the yoke 5, which is sandwiched between the other end where the through hole 8 is provided and the other end of the pump housing where the suction port 2 is provided. a pump chamber 4 coupled to the yoke 5; a field part 13 fixed to the cylindrical inner circumferential surface of the yoke 5; a self-aligning bearing 9; a rotating shaft 11 provided inside the yoke 5, which is rotatably supported by the self-aligning bearing 9, passes through a through hole 8 of the yoke 5, and projects into the pump chamber 4; , holding an armature 10 fixed on the rotating shaft 11 and facing the field part 13, and the other bearing 16 coupled to the opening of the yoke 5 and pivotally supporting the rotating shaft 11; Discharge side bearing holding member 15 having discharge port 17
An electric pump characterized by being equipped with.