JPH054773U - Electric motor - Google Patents

Abstract

(57) [Summary] [Purpose] To facilitate the assembly of magnets. An annular shape having an inner housing 27 which is assembled by fitting in the housing 1 and a holder piece 32 which is engaged between a pair of magnets 25, is formed in the inner housing 27 along its axial direction. The magnet holder 30 is engaged with each other, and the pair of magnets 25 are assembled between the holder pieces 32 in the inner housing 27 along the axial direction thereof.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to, for example, an electric fuel pump for an automobile, or an electric motor used as a rotary drive source.

[0002]

[Prior Art]

 As is well known, in this type of electric motor, a pair of magnets are symmetrically arranged in the housing at predetermined intervals in the circumferential direction. The magnet is generally directly attached to the recessed inner peripheral surface of the central portion of the housing. Incidentally, such an electric motor is disclosed in, for example, Japanese Utility Model Publication No. 1-19578 or Japanese Patent Laid-Open No. 62-107664.

[0003]

[Problems to be solved by the device]

 However, according to the conventional electric motor, the magnet is assembled in a deep position in the housing, so that care must be taken to properly perform the assembly, and the assembly work is complicated.

Therefore, the present invention has been made to solve the above-mentioned problems, and an object thereof is to provide an electric motor capable of easily assembling a magnet.

[0005]

[Means for Solving the Problems]

 The electric motor according to the present invention for solving the above-mentioned problems is an electric motor in which a pair of magnets are symmetrically arranged in a housing at predetermined intervals in a circumferential direction, and an inner housing assembled by fitting in the housing. And a magnet holder which has an annular shape with a holder piece engaged between each of the magnets and which is engaged in the inner housing along the axial direction thereof. It is assembled along the axial direction between the holder pieces in the inner housing.

[0006]

[Action]

 According to the above means, the magnet holder is engaged with the inner housing along the axial direction thereof, and the pair of magnets is assembled between the holder pieces of the magnet holder inside the inner housing along the axial direction thereof. The magnet is arranged with respect to the housing by fitting the inner housing in which the magnet is assembled into the housing.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In this example, as an example of the electric motor, an in-tank electric fuel pump in which an electric motor and a pump are integrally incorporated and which is placed in a fuel tank of an automobile or the like in a dipped state will be taken as an example. .. In FIG. 1, which is a sectional view of an electric fuel pump, stepped portions 2 and 3 are formed on the inner peripheral surfaces of the upper and lower end portions of a cylindrical metal housing 1, respectively. Further, at the lower end portion of the housing 1, a protrusion 4 protruding on the inner side surface thereof is formed by stamping.

A synthetic resin motor body 6 is fitted to the upper end of the housing 1. The upper end 1a of the housing 1 is caulked to the body 6. An outer peripheral stepped portion (reference numeral omitted) of the motor body 6 is butted against the upper stepped portion 2 of the housing 1. A synthetic resin pump cover 9 is fitted to the lower end of the housing 1. A motor chamber 10 is formed between the cover 9 and the motor body 6. An outer peripheral step (not shown) of the pump cover 9 is butted against the lower step 3 of the housing 1.

Further, a synthetic resin pump body 13 is fitted to the lower end of the housing 1. The lower end 1b of the housing 1 is caulked to the pump body 13. A pump chamber 14 is formed between the body 13 and the pump cover 9. A suction port 15 is formed in the pump body 13 from the outside to the pump chamber 14, and a flow port 16 is formed in the pump cover 9 from the pump chamber 14 to the motor chamber 10. Since this example is a Wesco type two-stage pump, a synthetic resin pump plate 17 is interposed between the pump cover 9 and the pump body 13. The outer grooves of the pump cover 9 and the pump plate 17 are formed with grooves 9a and 17a along the axial direction thereof. The grooves 9a and 17a are axially engaged with the projection 4 of the housing 1, and the pump cover 9 and the pump plate 17 are positioned with respect to the housing 1 in the circumferential direction.

An armature 19 is arranged in the motor chamber 10. Both ends of the shaft 20 of the armature 19 are rotatably supported by the motor body 6 and the pump cover 9 via bearings. The lower end of the shaft 20 extends into the pump chamber 14, and two impellers 23 are connected to the shaft end. The motor body 6 accommodates a pair of brushes 40, a choke coil 41 and the like (one is shown in the figure). The brush 40 is brought into contact with the commutator 19a of the armature 19 by a spring 42.

Further, the motor body 6 is formed with a discharge port 43 for discharging the fuel delivered from the pump chamber 14 to the motor chamber 10. A check valve 44 is arranged at the discharge port 43 in a state of being biased in a closing direction by a spring 45. Although not shown, a fuel supply pipe or the like that communicates with a fuel injection valve of an automobile engine is connected to the discharge port 43. The socket 46 of the motor body 6 is provided with terminals 8 (not shown) that are electrically connected to the brushes 40 through the choke coils 41.

Within the housing 1, a pair (two) of rare earth magnets 25 having an arcuate cross section are symmetrically arranged at a predetermined interval in the circumferential direction. The arrangement structure of the magnet 25 will be described with reference to FIG. 2 and FIG. 2 which is a sectional view taken along the line II-II of FIG. 1 in addition to FIG. A cylindrical metal inner housing 27 is fitted into the housing 1. A synthetic resin magnet holder 30 for holding the magnet 25 is arranged in the inner housing 27. As shown in the perspective view of FIG. 6, the magnet holder 30 has a ring-shaped holder main body 31 which is in surface contact with the lower end surface of the inner housing 27. A pair of holder pieces 32 located at are projected. The holder main body 31 is prevented from rotating by engaging an engaging projection 34 protruding on the upper surface of the outer peripheral portion thereof with an engaging groove 33 formed at the lower end of the inner housing 27. This state is often shown in the side view of FIG. By attaching the magnet 25 and the magnet holder 30 to the inner housing 27, a magnet assembly MA is obtained. A perspective view of the magnet assembly MA is shown in FIG. 3, and an exploded perspective view thereof is shown in FIG.

Further, as shown in the side views of FIGS. 1 and 5, a groove 36 is formed on the side surface of the holder main body 31 opposite to the engaging projection 34 along the axial direction thereof. .. The groove 36 is engaged with the stamping protrusion 37 stamped at the corresponding position of the housing 1 along the axial direction from the upper side in the drawing to move the magnet holder 30 to the housing 1. Positioned in the circumferential direction. The movement of the magnet assembly MA in the housing axial direction is restricted by the motor body 6 and the pump cover 9. Further, in FIG. 7 showing a side view of the connecting portion between the magnet assembly MA and the motor body 6, and FIG. 8 showing a sectional view taken along the line VIII-VIII of FIG. 7, the motor body 6 has a plurality of protruding pieces 6a. It is projected. A protrusion 38 protruding from the upper end of the inner housing 27 is engaged between the protrusions 6a along the housing axial direction, whereby the inner housing 27 is positioned in the circumferential direction. There is.

In the electric fuel pump described above, the armature 19 rotates by being driven by the battery of the automobile as a power source, and the impeller 23 rotates accordingly, so that the fuel in the fuel tank is pumped by the pump body 13. Is pumped up to the motor chamber 10 through the pump chamber 14 and the circulation port 16 of the pump cover 9, and is discharged from the discharge port 43 of the motor body 6.

Next, a procedure for assembling the electric fuel pump will be described. First, in FIG. 6, the magnet holder 30 is engaged with the inner housing 27 from below along the axial direction thereof, and the pair of magnets 25 are arranged between the holder pieces 32 of the magnet holder 30 in the inner housing 27. It is inserted from above along the axial direction and assembled as the magnet assembly M A shown in FIG. At this time, the engagement groove 33 of the inner housing 27 is engaged with the engagement projection 33 of the magnet holder 30 to prevent the rotation of the magnet holder 30. At the same time, the holder piece 32 of the magnet holder 30 causes the magnet 32 to rotate in the circumferential direction. Will be positioned.

Next, the inner housing 27 of the magnet assembly MA is fitted into the housing 1 from above along the axial direction thereof, whereby the magnets 25 are arranged with respect to the housing 1. At this time, by engaging the groove 36 of the magnet holder 30 with the projection 37 of the housing 1, the magnet assembly MA is positioned in the circumferential direction. After that, the motor body 6 is fitted into the housing 1 along the axial direction from above. At this time, the protruding portion 38 of the inner housing 27 is relatively engaged between the protruding pieces 6a of the motor body 6. The brush 40, the choke coil 41, the spring 42, etc. are assembled to the motor body 6 before the assembly. The motor body 6 is accurately positioned with respect to the housing 1 by the engagement of the projection and the groove, as in the positioning of the magnet holder 30, for example. After fitting the motor body 6, the upper end 1a of the housing 1 is caulked as shown in FIG. 1 to fix the body 6.

Further, together with the assembly of the motor body 6, the pump cover 9 is fitted into the housing 1 from below along the axial direction thereof. At this time, the groove 9a of the pump cover 9 is engaged with the protrusion 4 of the housing 1 along its axial direction. When assembling the motor body 6 or the pump cover 9, the armature 19 is arranged in the housing 1, and the shaft 20 thereof is pivotally supported by them. Next, after inserting one impeller 23 into the shaft 20 of the armature 19, the pump plate 17 is fitted into the housing 1 along the axial direction thereof. At this time, the groove 17a of the pump plate 17 is engaged with the protrusion 4 of the housing 1 along its axial direction. Further, after inserting the other impeller 23 into the shaft 20 of the armature 19, the pump body 13 is fitted into the housing 1 along its axial direction, and the lower end portion 1b of the housing 1 is caulked to fix the body 13. To do. The electric fuel pump is assembled as described above.

According to the electric fuel pump, the pair of magnets 25 are assembled in the inner housing 27 together with the magnet holder 30, and the inner housing 27 is fitted into the housing 1 so that the housing 1 The arrangement of the magnet 25 with respect to is made. Therefore, the assembly work of the magnet 25 can be performed more easily than the conventional assembly of the magnet directly into the housing.

According to the electric fuel pump, when a rare earth magnet is used as the magnet 25 to obtain a high output motor, the total thickness of the rare earth magnet 25 and the inner housing 27 is made equal to that of a conventional magnet. By doing so, it is possible to commonly use other parts.

[0020]

[Effect of the device]

 According to the present invention, a pair of magnets is assembled in the inner housing together with the magnet holder, and the magnets can be arranged with respect to the housing by fitting the inner housing into the housing. Therefore, the magnet is directly attached to the conventional housing. It is easier to assemble the magnet than the one that is assembled to.

[Brief description of drawings]

FIG. 1 is a sectional view of an electric fuel pump according to a first embodiment.

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

FIG. 3 is a perspective view of a magnet assembly.

FIG. 4 is a bottom left side view of the magnet assembly.

FIG. 5 is a right side view of the lower portion.

FIG. 6 is an exploded perspective view of a magnet assembly.

FIG. 7 is a side view of a rotation stopping portion of the magnet assembly.

8 is a sectional view taken along line VIII-VIII in FIG.

[Explanation of symbols]

 1 Housing 25 Magnet 27 Inner Housing 30 Magnet Holder 32 Holder Piece

Claims (1)

Claims for utility model registration: 1. An electric motor in which a pair of magnets are symmetrically arranged in a housing at predetermined intervals in a circumferential direction. A housing, and a magnet holder which has an annular shape with a holder piece engaged with each other between the magnets, and which is engaged in the inner housing along the axial direction thereof. An electric motor assembled between the holder pieces in the inner housing along the axial direction thereof.