JP3363095B2 - Brushless motor and centerpiece of brushless motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer rotor type brushless motor which is particularly suitable for a blower motor of a vehicle air conditioner.

[0002]

2. Description of the Related Art The present applicant has previously proposed various outer rotor type brushless motors suitable for a blower motor of a vehicle air conditioner. In this outer rotor type brushless motor, the stator is fixed to the upper surface of the motor holder.
The stator includes a center piece and a core supported by the center piece and having a winding wound around the core.

The center piece is composed of a flange portion and a substantially cylindrical shaft support portion for holding the core. A pair of upper and lower support recesses for holding two bearings are formed on the inner peripheral surface of the shaft support portion. The two bearings held by the supporting recess rotatably support the rotating shaft to which the rotor is fixed. That is, the center piece supports the stator and also supports the rotating shaft so as to be rotatable.

By the way, in order to reduce the cost of the brushless motor, it is conceivable to mold the center piece with a synthetic resin. However, the center piece formed with a synthetic resin is not very accurate and has rigidity (strength). Is low, it is necessary to increase the wall thickness, which may increase the size of the entire motor. Further, since the synthetic resin has a poor thermal conductivity, the heat generated by the windings of the stator cannot be radiated through the center piece, and the heat generation causes a malfunction of the motor. Therefore,
In order to improve strength, accuracy and heat dissipation, the center piece is made of aluminum alloy and is molded by the die casting method.

[0005]

By the way, the molding accuracy of the die casting method is limited, and the center piece molded by aluminum die casting has the accuracy (concentricity) of the supporting recess (inner hole) for fitting and holding both the bearings. ), It was necessary to cut the supporting recess (inner hole). Therefore, there is a problem that the man-hours for manufacturing the center piece and the cost cannot be reduced.

An object of the present invention is to provide a brushless motor and a centerpiece of the brushless motor, which can maintain excellent mechanical properties and can reduce the number of manufacturing steps and cost.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is a cylinder of a centerpiece in which a flange portion of a centerpiece is fixed to a motor holder and is projected from the flange portion. In a brushless motor in which a stator core is attached to the outer side of the portion and a rotating shaft is rotatably supported via a bearing inside, a center piece including the flange portion and a cylindrical portion is formed by press working , Axial direction of the cylindrical part of the center piece
Position the bearing supporting the rotating shaft in the axial direction at the intermediate position
Projects inward in the radial direction of the cylindrical portion for fixed support
The point is that a step is provided .

[0008] According to a second aspect of the invention, in the brushless motor according to claim 1, the front Kidan difference portion is summarized in that formed cut radially inward of the cylindrical portion.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the brushless motor according to the above item 1, the center piece is formed of a plate material of a metal material. According to a fourth aspect of the present invention, in the brushless motor according to any one of the first to third aspects, a large diameter that is separated from an outer peripheral surface of the rotary shaft is provided in a part of an axial direction of the rotary shaft insertion hole of the bearing. The gist is that the holes are formed.

According to a fifth aspect of the present invention, the flange portion fixed to the motor holder and the flange portion are formed to project.
In a center piece of a brushless motor having a cylindrical portion that rotatably supports a rotating shaft through a bearing and mounting a stator core on the outside, the center piece is formed by press working , and the center piece of
A bearing that supports the rotating shaft at an axially intermediate position of the cylindrical portion.
Radial direction of the cylindrical portion for axially positioning and supporting the
The gist is that a step portion that protrudes inward is provided .

(Operation) According to the first and second aspects of the present invention, since the press working is a kind of high-precision forming, it is possible to improve the forming accuracy of the center piece formed by the press working. As a result, there is no need for cutting after the forming process, and the number of manufacturing steps and the processing cost of the brushless motor having the center piece can be reduced.

Further, bearing Ru press-fitted to the rotary shaft insertion hole of the cylindrical portion, it is possible to be supported in the axial direction by the respective stepped portions can be positioned in the axial direction.

According to the third aspect of the present invention, the strength and rigidity of the center piece as the skeleton of the entire brushless motor can be improved. Further, heat dissipation of the stator is easily performed via the center piece.

According to the fourth aspect of the present invention, even if the cylindrical portion in the vicinity of the center piece is slightly deformed inward due to the formation of the projecting portion of the center piece, the large-diameter hole portion absorbs the amount of deformation. The bearing can be easily press fitted into the rotary shaft insertion hole of the cylindrical portion. As a result, the shaft bearing of the bearing can be maintained with high accuracy, and the accuracy of the rotary shaft center of the rotary shaft also becomes good.

According to the fifth aspect of the present invention, since the press working is a kind of high precision forming, it is possible to improve the forming precision of the center piece formed by the press working. As a result, there is no need for cutting after the forming process, and the man-hours for manufacturing the center piece and the processing cost can be reduced. Also, press the rotary shaft insertion hole
The mating bearings are axially supported by the steps.
Can be held and axially positioned
be able to.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an outer rotor type brushless motor used as a blower motor of a vehicle air conditioner will be described below with reference to FIGS.

As shown in FIG. 1, a stator 2 is fixed to the center of the upper surface 1a of the motor holder 1. The stator 2 includes a center piece 3, a core 4, and a winding wire 5.

As shown in FIG. 3, the center piece 3
Is a substantially disk-shaped flange portion 3 integrally formed by pressing a plate material of a metal material (for example, iron alloy or steel).
a, and a cylindrical portion 3b formed so as to project upward at the center of the upper surface of the flange portion 3a.

A plurality of boss portions 3c perpendicular to the lower surface of the flange portion 3a are formed on the lower surface of the flange portion 3a so as to project therefrom. In this embodiment, the three boss portions 3c
Are formed on the outer peripheral portion of the lower surface of the flange portion 3a. The inner hole 3d of the boss portion 3c penetrates the flange portion 3a. Moreover, the inner hole 3d is screwed by post-processing. Further, the flange portion 3a is formed with three through holes 3e at positions close to the cylindrical portion 3b. Further, a linear portion 3f and a concave portion 3g are cut out on the outer peripheral surface of the flange portion 3a.

A small diameter portion 3h is formed at the tip of the cylindrical portion 3b. The inner hole 3i of the cylindrical portion 3b is formed so as to penetrate the flange portion 3a. Also, the cylindrical portion 3
At the axially intermediate position of b, a plurality of punched-out portions 3j are formed from the outer peripheral surface toward the inner hole 3i. In the present embodiment, four punched-out portions 3j are formed symmetrically with respect to the central axis of the cylindrical portion 3b by being divided into upper and lower stages. As shown in FIG. 1, the punched-out portion 3j comes to project from the inner peripheral surface of the cylindrical portion 3b toward the central axis,
The step portion 3k is formed.

Then, as shown in FIG. 2, by inserting the cylindrical portion 3b into the inner hole 4a of the core 4, the core 4 is fitted and supported by the cylindrical portion 3b. Inner hole 3 of cylindrical portion 3b
i is a pair of first and second bearings 6a, 6a,
6b is press-fitted. As shown in FIG. 1, the first and second bearings 6a and 6b are axially supported by the stepped portion 3k, and their axial positions are also determined.

Further, the first and second bearings 6a, 6b
Has large diameter portions 6c and 6d at one end. In FIG. 1, the inner holes 6e and 6f as the rotary shaft insertion holes of the first and second bearings 6a and 6b are formed with large diameter hole portions 6g and 6h at axial portions corresponding to the large diameter portions 6c and 6d. Has been done.

Then, as shown in FIGS. 1 and 2, from the upper side of the stator 2 constructed as described above, the rotary shaft 10 of the rotor 7 is inserted into the inner holes 6 of the first and second bearings 6a and 6b.
The rotor 7 is inserted and fitted in the e and 6f,
It is rotatably supported by the stator 2. At this time, the bell-shaped yoke 8 forming the rotor 7 covers the stator 2, and the plurality of magnets 9 fixed to the inner peripheral surface of the yoke 8 are arranged around the core 4. It has become.

Further, on the lower surface of the motor holder 1,
The circuit board 11 on which the excitation circuit is mounted is fixed. Then, when an exciting current is supplied from the exciting circuit to the winding 5 of the stator 2, a rotating magnetic field is generated in the stator 2, and the rotor 7 is rotationally driven based on the rotating magnetic field.

Next, the features of the brushless motor configured as described above will be described. (1) In the present embodiment, the flange portion 3a and the cylindrical portion 3b formed so as to project upward at the center of the upper surface of the flange portion 3a.
The center piece 3 composed of and was integrally molded by press working. Therefore, the molding accuracy of the center piece 3 can be ensured. As a result, the need for cutting after molding is eliminated, and the number of manufacturing steps and processing cost of the brushless motor can be reduced.

(2) Further, in this embodiment, a plurality of punched portions 3j are provided at the axially intermediate position of the cylindrical portion 3b from the outer peripheral surface toward the inner hole 3i, and the punched portions 3j allow the cylindrical portion 3j to be formed. The inner peripheral surface of 3b was projected to the central axis side to form the step portion 3k. Therefore, the first and second bearings 6a and 6b, which are press-fitted into the inner hole 3i of the cylindrical portion 3b, can be axially supported by the stepped portion 3k and can be positioned in the axial direction. it can.

(3) In this embodiment, the center piece 3
Is integrally formed by pressing with a plate material of a metal material (for example, iron alloy or steel). Therefore, the strength and rigidity of the center piece 3 as the skeleton of the entire brushless motor can be improved. In addition, heat is easily dissipated from the winding 5 of the stator 2 through the center piece 3 made of a metal material.

(4) In this embodiment, the first and second bearings 6a and 6b are formed with large diameter portions 6c and 6d at one end. The inner holes 6e and 6f of the first and second bearings 6a and 6b are
Large-diameter hole portions 6g, 6h are formed at one end corresponding to the large-diameter portions 6c, 6d so as to be separated from the outer peripheral surface of the rotary shaft 10.
Therefore, even if the cylindrical portion 3b in the vicinity thereof is slightly deformed to the inner surface due to the formation of the punched-out portion 3j, the large-diameter hole portion 6 is formed.
By absorbing the amount of deformation by g and 6h, the first and second bearings 6a and 6b can be easily press fitted into the inner hole 3i of the cylindrical portion 3b. As a result, the shaft bearings of the first and second bearings 6a and 6b can be maintained with high accuracy, and the accuracy of the rotational axis of the rotary shaft 10 can be improved.

The above embodiment may be modified as follows. In the above-mentioned embodiment, the center piece 3 is integrally formed by press working with a metal plate material such as iron alloy or steel, but is excellent in strength (rigidity), thermal conductivity and plastic working (press working). As long as it is a metallic material, it may be press-molded with a plate material such as a copper alloy, a zinc alloy, and stainless. In this case, the same effect as that of the above embodiment can be obtained.

In the above embodiment, the axially intermediate position of the cylindrical portion 3b of the center piece 3 is divided into upper and lower two stages.
Although four punched-out portions 3j were formed at symmetrical positions with respect to the central axis of the cylindrical portion 3b, the cylindrical portion 3b was used.
At the axial middle position of the
You may implement by forming the punching-out part 3j or more pieces.
In this case, the same effect as that of the above embodiment can be obtained.

In the above embodiment, the present invention is embodied in an outer rotor type brushless motor used as a blower motor of a vehicle air conditioner, but may be embodied in another brushless motor. In this case, the same effect as that of the above embodiment can be obtained.

[0032]

As described in detail above, according to the first and second aspects of the present invention, it is possible to reduce the number of manufacturing steps and the processing cost of the brushless motor.

Further, bearing Ru press-fitted to the rotary shaft insertion hole of the cylindrical portion, it is possible to be supported in the axial direction by the respective stepped portions can be positioned in the axial direction.

According to the third aspect of the invention, the strength and rigidity of the center piece as the skeleton of the entire brushless motor can be improved. Further, heat dissipation of the stator is easily performed via the center piece.

According to the fourth aspect of the present invention, the shaft bearing of the bearing can be maintained with high accuracy, and the accuracy of the rotary shaft center of the rotary shaft also becomes good. According to the invention described in claim 5, it is possible to reduce the number of manufacturing steps and the processing cost of the center piece. Also, press the rotary shaft insertion hole
The mating bearings are axially supported by the steps.
Can be held and axially positioned
be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a brushless motor according to an embodiment.

FIG. 2 is an exploded perspective view for explaining the brushless motor as well.

FIG. 3 is a perspective view of the center piece of the brushless motor.

[Explanation of symbols]

2 ... Stator, 3 ... Centerpiece, 3b ... Cylindrical part, 3
k ... step portion, 4 ... stator core, 6a, 6b ... bearing, 6
e, 6f ... Inner hole as rotation shaft insertion hole, 6g, 6h ... Large diameter hole portion, 10 ... Rotation shaft.

Claims (5)

(57) [Claims] 1. A flange portion (3) of the center piece (3).
(a) is fixed to the motor holder (1), the stator core (4) is attached to the outside of the cylindrical portion (3b) of the center piece (3) protruding from the flange portion (3a), and the bearing ( 6a, 6b) through the rotary shaft (1
0) in a rotatably supported manner, a center piece (3) including the flange portion (3a) and the cylindrical portion (3b) is formed by press working , and
Axial intermediate position of the cylindrical portion (3b) of the tarpiece (3)
Bearings (6a, 6b) supporting the rotating shaft (10)
The cylindrical part (3b) for positioning and supporting the shaft in the axial direction
A brushless motor having a step portion (3k) protruding inward in the radial direction . 2. A brushless motor, characterized in that the brushless motor according to claim 1, before Kidan difference portion (3k) formed cut radially inward of the cylindrical portion (3b). 3. The brushless motor according to claim 1, wherein the center piece ( 3 ) is formed of a metal plate material. 4. The brushless motor according to claim 1, wherein the rotary shaft insertion holes (6e, 6f) of the bearings (6a, 6b).
A large diameter hole portion (6g, 6h) separated from the outer peripheral surface of the rotating shaft (10) is formed in a part of the axial direction of the brushless motor. 5. A motor holder (1) in full run <br/> di part fixed and (3a), formed to project from the flange portion (3a), on the inside as well as attaching the stator core (4) on the outside Bearing (6a, 6
In a center piece of a brushless motor having a cylindrical portion (3b) that rotatably supports a rotating shaft (10) via b), the center piece (3) is formed by press working , and
Axial middle of the cylindrical portion (3b) of the center piece (3)
The bearings ( 6a, 6a ) that support the rotating shaft (10) at the position.
The cylindrical portion (3) for axially positioning and supporting b).
A center piece of a brushless motor, which is provided with a step portion (3k) protruding inward in the radial direction of b) .