JP2012039793A - Brushless motor - Google Patents

Abstract

An object of the present invention is to provide an inexpensive brushless motor that can easily manage the inner diameter of a housing and the outer diameter of a stator core, reduce the number of parts, and reduce the number of assembly steps.
A stator 2 is held on an inner diameter side of a housing 1. The rotor 4 is disposed on the inner diameter side of the stator 2 via a gap with respect to the stator. The terminal block 3 is made of resin mold, and the stator 2 and the terminal block 3 are integrated by resin molding. The inner diameter of the housing 1 is larger than the outer diameter of the armature core 2c. The stator 2 is held with respect to the housing 1 by fixing the terminal block 3 to the housing 1.
[Selection] Figure 1

Description

  The present invention relates to a brushless motor, and more particularly, to a brushless motor characterized by a stator fixing method.

  In recent years, there has been a tendency to make vehicle auxiliary machines such as oil pumps electric to reduce fuel consumption of vehicles. As the motor for driving these auxiliary machines, a permanent magnet field-type brushless motor has been used because it is required to be small and light and have a long life. There is also a strong demand for low cost.

  A conventional permanent magnet field-type brushless motor has a terminal block in which a stator, a rotor having a permanent magnet, and a plurality of terminals having a connector portion for supplying power to an armature winding are arranged in a housing. Built-in. The open end side of the housing on the output shaft side is configured by mounting a flange that also serves as a cover made of aluminum alloy or the like. The stator has an armature core, and the armature core is press-fitted into the housing or fixed by shrink fitting (for example, see Patent Document 1).

JP 2007-221978 A

  In the brushless motor described in Patent Literature 1, since the armature core is press-fitted into the housing or fixed by shrink fitting, it is necessary to increase the dimensional accuracy of the inner diameter of the housing and the outer diameter of the stator core. It was difficult to manage.

  The terminal block is arranged as a separate part in parallel with the stator in the axial direction, and electrically connects the coil end and the terminal. For this reason, there are problems that the number of parts increases and time is required for assembly.

  An object of the present invention is to provide an inexpensive brushless motor that can easily manage the inner diameter of a housing and the outer diameter of a stator core, reduce the number of parts, and have fewer assembly steps.

(1) In order to achieve the above object, the present invention provides a cylindrical metal housing, a stator held on the inner diameter side of the metal housing, and a metal housing rotatably supported by the metal housing. And having a rotor disposed on the inner diameter side of the stator with a gap with respect to the stator and a terminal block on which a plurality of terminals are disposed, and the stator is disposed on the inner peripheral surface side. An armature core provided with a plurality of salient poles arranged at equal intervals; and an armature winding wound around each of the salient poles; and the terminal of the terminal block includes the armature winding A brushless motor electrically connected to the coil end of the wire, wherein the terminal block is made of resin mold, and the stator and the terminal block are integrated by resin mold, and the inner diameter of the metal housing is Than the outer diameter of the armature core And a hearing things, by fixing the terminal block to the metal housing, the stator is what is held against the metal housing.
With this configuration, it is possible to easily manage the inner diameter of the housing and the outer diameter of the stator core, reduce the number of parts, and reduce the number of assembly steps.

  (2) In the above (1), preferably, a connector for connecting the terminal to the outside is provided, and the connector is integrally formed on the terminal block by a resin mold.

  (3) In the above (1), preferably, the terminal block is used as a cover for closing the open end side of the housing.

  (4) In the above (1), preferably, the terminal block is provided with a flange for attachment to the housing, which is integrally molded.

  (5) In the above (1), preferably, the terminal block is provided with a concave groove at a position where the terminal block is fitted to the inner peripheral surface of the housing, and an elastic sealing member accommodated in the groove. It is a thing.

  According to the present invention, dimensional management of the inner diameter of the housing and the outer diameter of the stator core is easy, the number of parts can be reduced, and the assembly process can be reduced.

It is a longitudinal cross-sectional view of the brushless motor by one Embodiment of this invention. 1 is an exploded view of a brushless motor according to an embodiment of the present invention. It is the front view which looked at the brushless motor by one Embodiment of this invention from the connector side. It is sectional drawing of the AA line of FIG.

Hereinafter, the configuration of a brushless motor according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a longitudinal sectional view of a brushless motor according to an embodiment of the present invention. FIG. 2 is an exploded view of a brushless motor according to an embodiment of the present invention. FIG. 3 is a front view of the brushless motor according to the embodiment of the present invention as viewed from the connector side. 4 is a cross-sectional view taken along line AA in FIG.

  As shown in FIG. 1, the housing 1 is made of aluminum die cast and has a cylindrical shape (a cup shape having a through hole at the bottom). A housing 2, a rotor 4, and a ball bearing 5 are accommodated in the housing 1. A terminal block 3 is attached to the opening end of the housing 1.

  As shown in FIG. 4, the armature core 2a of the stator 2 has a plurality of salient poles 2b arranged at equal intervals on the inner peripheral surface side. In the illustrated example, there are nine salient poles 2b, and slots are formed between adjacent salient poles 2b. The armature core 2a is formed by laminating a plurality of thin magnetic steel plates press-punched into the shape shown in FIG. 4 and caulking them together as shown in FIG.

  An insulating bobbin 13 is formed by resin molding on the inner periphery of the slot formed between adjacent salient poles 2b shown in FIG. Further, as shown in FIG. 1, the resin mold integrally forms a resin hold portion 13a for holding the armature winding 2c at both ends in the axial direction of the salient pole magnetic pole 2b.

  As shown in FIG. 4, the armature winding 2c is wound around the salient pole magnetic pole 2b by concentrated winding to form a three-phase winding. The salient pole magnetic pole 2b and the armature winding 2c are insulated by the above-described insulating bobbin 13. In the example shown in FIG. 4, since there are nine slots, three U-phase, V-phase, and W-phase windings (each phase coil) are provided.

  As shown in FIG. 1, the coil end 2d for each phase of the armature winding 2a is electrically connected to the terminal 6 by fusing or the like. In addition, as shown in FIG. 4, three terminals 6 are provided corresponding to each of the three phases. Electric power to the brushless motor is supplied to a three-phase coil from a power source (not shown) via a terminal 6.

  In the example shown in FIG. 1, after the coil end 2d for each phase of the armature winding 2a is connected to the terminal 6, the terminal 6 for each phase is resin-molded together with the armature core 2a and the armature winding 2c. The terminal block 3 is formed. The resin portion 3a of the terminal block 3 is molded so as to enter between the armature windings 2c as shown in FIG. 4 which is a cross-sectional view taken along line AA in FIG. The strong conclusion is made strong.

  As shown in FIG. 1, the connector housing 3 b is also integrally formed with the terminal block 3. The terminal 6 protrudes inside the connector housing 3b.

  As shown in FIGS. 2 and 4, flanges 3d are integrally formed of resin at three locations on the outer periphery of the terminal block 3, and at that time, a metal pipe-like collar 16 is embedded in the flange 3d. It is.

  Further, as shown in FIG. 1, a groove 3 c is formed on the outer periphery of the resin portion 3 a of the terminal block 3. A hard rubber O-ring 7 is incorporated in the groove 3c.

  As shown in FIG. 1, the rotor 4 includes a permanent magnet 9, a yoke 10, and a shaft 11. The yoke 10 is obtained by sintering iron-based powder and then molding it with a press to finish it with necessary accuracy. The permanent magnet 9 is bonded to the outer periphery of the yoke 10 at equal intervals. In this example, six permanent magnets 9 are used. Adjacent permanent magnets 9 are magnetized so that their polarities are opposite to each other. Therefore, the brushless motor of this embodiment is a concentrated winding brushless motor having 6 poles and 9 slots. The yoke 10 is press-fitted and fixed to the rotating shaft 11. Further, the shaft 11 is press-fitted and fixed to the inner ring of the ball bearing 5 holding the outer ring in the housing 1 and has a structure that can freely rotate.

  One end of the shaft 11 (the left end portion in the drawing) is connected to a vehicle auxiliary machine that is a driven body such as an oil pump, and drives the auxiliary machine. As shown in FIGS. 1 and 3, protrusions 1 a are integrally formed at three locations on the outer periphery of the housing 1. The protrusion 1a has a hole 1b. The brushless motor of this embodiment is attached and fixed to the auxiliary machinery using bolts or the like using the holes 1b. In addition, when the outer peripheral housing of auxiliary equipment such as an oil pump is formed by aluminum die casting, the outer peripheral housing of the auxiliary equipment and the housing 1 of the brushless motor of the present embodiment can be integrally formed. In this case, the protrusion 1a is not necessary.

  Next, the assembly process of the brushless motor of this embodiment is demonstrated using FIG.

  The outer diameter of the armature core 2 a is smaller than the inner diameter of the housing 1. For example, the outer diameter of the armature core 2a is smaller than the inner diameter of the housing 1 by about 200 μm. As described above, the outer diameter of the armature core 2a is determined by press punching. On the other hand, the inner diameter of the housing 1 is determined by aluminum die casting. When the armature core 2a and the housing 1 are molded by such a manufacturing method, the outer diameter cutting process of the armature core 2a and the inner diameter cutting process of the housing 1 are not performed. A predetermined gap dimension can be provided.

  The armature core 2a held by the terminal block 3 is inserted into the housing 1 in the state shown in FIG. The fit between the outer diameter of the armature core 2a and the inner diameter of the housing 1 is a clearance fit and no mechanical fastening force. The fit between the outer diameter of the terminal block 3 and the inner diameter of the housing 1 is also a clearance fit. The terminal block 3 is formed with a concave groove 3c in a resin portion 3a that is fitted to the inner peripheral surface of the housing 1, and a hard rubber O-ring 7 is incorporated in the groove 3c. The outer diameter of the O-ring 7 is slightly larger than the inner diameter of the housing 1. The O-ring 7 seals between the inner diameter of the housing 1 and the groove 3c of the terminal block 3 to prevent water and dust from the outside from entering the motor.

  The mechanical holding of the stator 2 is performed by mechanically fixing a flange 3 d formed of a part of the resin portion 3 a of the terminal block 3 to the housing 1 with screws 8. As described above, the housing 1 has a cylindrical shape (a cup shape having a through hole at the bottom), and an opening for inserting the stator 2 is formed on one side. After the stator 2 is inserted through the opening, the terminal block 3 is fixed to the housing 1 with screws 8, so that the opening of the housing 1 is covered with the terminal block 3.

  The O-ring 7 is used for aligning the armature core 2 a with respect to the inner periphery of the housing 1. Therefore, the central axis of the armature core 2 a coincides with the central axis of the housing 1. On the other hand, the central axis of the rotor 10 coincides with the central axis of the housing 1 by being held by the bearing 5. As a result, the gap formed between the outer periphery of the rotor 1 and the inner periphery of the armature core 2a can be made constant.

  As described above, in the brushless motor of this embodiment, it is not necessary to press-fit or shrink-fit the stator 2 armature core 2a into the housing 1, and the inner diameter of the housing 1 and the outer diameter of the armature core 2a can be reduced. Dimension management becomes easy.

  Further, since the stator 2 and the terminal block 3 can be integrated, the number of parts can be reduced, and a brushless motor with few assembly processes can be obtained.

  INDUSTRIAL APPLICABILITY The present invention is effective in spreading a permanent magnet field type brushless motor suitable for use as a vehicle auxiliary machine. Increasing the number of models adopted has improved the efficiency of the system and has a great effect on environmental protection.

DESCRIPTION OF SYMBOLS 1 ... Housing 1a ... Projection part 1b ... Hole 2 ... Stator 2a ... Armature core 2b ... Salient pole 2c ... Armature winding 2d ... Coil end 3 ... Terminal block 3a ... Resin part 3b ... Connector housing 3c ... Groove part 3d ... Flange 4 ... Rotor 5 ... Ball bearing 6 ... Terminal 7 ... O-ring 8 ... Screw 9 ... Permanent magnet 10 ... Yoke 11 ... Rotating shaft 13 ... Insulating bobbin 13a ... Resin hold 16 ... Color

Claims (5)

A cylindrical metal housing, a stator held on the inner diameter side of the metal housing, and rotatably supported with respect to the metal housing, and on the inner diameter side of the stator with respect to the stator And having a rotor arranged through a gap and a terminal block on which a plurality of terminals are arranged,
The stator has an armature core provided with a plurality of salient poles arranged at equal intervals on the inner peripheral surface side, and an armature winding wound around each salient pole.
The terminal of the terminal block is a brushless motor that is electrically connected to a coil end of the armature winding,
The terminal block is made of a resin mold, and the stator and the terminal block are integrated by a resin mold,
The inner diameter of the metal housing is larger than the outer diameter of the armature core,
A brushless motor, wherein the stator is held against the metal housing by fixing the terminal block to the metal housing. The brushless motor according to claim 1,
With a connector for connecting the terminal to the outside,
The connector is integrally formed with the terminal block by a resin mold. The brushless motor according to claim 1,
The brushless motor, wherein the terminal block is used as a cover for closing the open end side of the housing. The brushless motor according to claim 1,
The terminal block includes a flange for mounting to the housing, which is integrally molded. The brushless motor according to claim 1,
The terminal block includes a concave groove at a position where the terminal block is fitted to the inner peripheral surface of the housing,
A brushless motor comprising an elastic seal member housed in the groove.

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