JP4152637B2 - Molded motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inner rotor type molded motor.
[0002]
[Prior art]
FIG. 3A is a longitudinal sectional view of a conventional inner rotor type molded motor 100.
[0003]
As shown in FIG. 3A, the mold motor 100 includes a donut-shaped control board 104 as shown in FIG. 3B on the rear side of the ring-shaped stator 102, and controls the stator 102 and the stator 102. The substrate 104 and the rear bracket 112 are integrally formed with a mold resin to form the motor body 106. The motor body 106 is provided with a rotor insertion space 110 for inserting the rotor 108.
[0004]
The rotor 108 is inserted from the front side of the rotor insertion space 110, and a rear bearing 114 that rotatably supports the rotating shaft 118 is held by the rear bracket 112.
[0005]
A front bearing 116 attached to the front portion of the rotating shaft 118 is held by a front bracket 120 that covers the front surface of the motor body 106.
[0006]
[Problems to be solved by the invention]
The molded motor 100 having the above configuration has the following problems.
[0007]
As shown in FIG. 3A, the first problem is that the diameter φdA for inserting the rotating shaft 118 of the rotor 108, the rear bracket 112, and the rear bearing 114 into the donut-shaped control board 104. It is necessary to provide the through-hole 128.
[0008]
Therefore, there is a problem that the effective area SA on the control board 104 is reduced by the amount of the through holes 128, the material for the control board 104 is poor, and the cost is increased.
[0009]
In addition, in order to increase the effective area SA, it is necessary to increase the diameter φD of the control board 104 and there is a problem that the mold motor 100 is increased.
[0010]
The second problem is that the control board 104 is covered with mold resin, so that heat dissipation is poor and electronic components 130 such as ICs that generate a lot of heat and electronic components such as driving ICs that are sensitive to heat are controlled. When used for the substrate 104, there is a problem that it leads to restriction of characteristics and deterioration of reliability.
[0011]
Therefore, in view of the above problems, the present invention provides a molded motor that can increase the effective area of a control board and efficiently dissipate heat from an electronic component.
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a ring-shaped stator in which a winding is wound around an iron core in which steel plates are laminated, a control board that constitutes a drive circuit by arranging electronic components and position detection elements, a rotating shaft, a yoke, and a cylinder And a metal bracket disposed on the front and rear for attaching a bearing that rotatably supports the front and rear portions of the rotating shaft, the stator, the control board, and the rear bracket. And forming a rotor insertion space inside the stator with a mold resin, and inserting the rotor into the rotor insertion space, thereby inserting the rotor inside the stator. in the inner rotor type molded motor disposing, the rear bracket which is integrally formed by molding resin, is projected from the inner portion of the motor body, said rotor, the magnet Length in the axial direction is formed longer than the axial length of the yoke of the control board is disposed in the rear of the rear bracket, an electronic component disposed on the control board distribution near the bottom surface of the rear bracket This is a molded motor.
[0013]
According to a second aspect of the present invention, a ring-shaped protrusion is provided on the outer periphery of the rear bracket, and a position detection element protruding from the control board is disposed on the ring-shaped protrusion. 2. The molded motor according to claim 1, wherein the molded motor is a molded motor.
[001 4 ]
[Operation]
With the molded motor according to claim 1, since the control board is arranged behind the rear bracket, there is no need to provide a through hole for penetrating the rear bracket or the like in the central portion of the control board. A large area can be taken.
[001 5 ]
Moreover , since the electronic component arranged on the control board is arranged near the bottom surface of the rear bracket, heat can be dissipated through the rear bracket.
[001 6 ]
In the molded motor according to the second aspect, since the electronic component disposed on the control board is disposed near the outer periphery of the rear bracket, heat can be dissipated through the rear bracket.
[001 7 ]
DETAILED DESCRIPTION OF THE INVENTION
(First Embodiment) A molded motor 10 according to a first embodiment of the present invention will be described with reference to FIG.
[001 8 ]
The molded motor 10 of this embodiment is a brushless DC motor, and is used for a fan or blower for an air conditioner.
[00 19 ]
FIG. 1A is a longitudinal sectional view of the molded motor 10.
[002 0 ]
As shown in FIG. 1A, the ring-shaped stator 12 of the molded motor 10 is obtained by winding a winding 16 around an iron core 14 in which donut-shaped steel plates are laminated.
[002 1 ]
On the rear surface side of the stator 12, a control board 18 constituting a drive circuit for the mold motor 10 is disposed. As shown in FIG. 1B, the control board 18 has a circular planar shape, and a through hole 20 passes through a central portion. The diameter of the control board 18 is φD, and the diameter of the through hole 20 is φdB. The role of the through hole 20 will be described later. Further, the control board 18 is provided with a position detection element 24 made up of a Hall element, a Hall IC, or the like for detecting the position of the electronic component 22 such as the drive IC or the rotor 28 constituting the drive circuit as described above. ing.
[002 2 ]
The stator 12, the control board 18 disposed on the rear surface side, and the rear bracket 32 made of iron are integrally formed with a molding resin by a molding die to form a motor body 26.
[002 3 ]
The motor body 26 is provided with a rotor insertion space 30 for inserting the rotor 28. A rear bracket 32 is disposed on the rear surface of the insertion space 30.
[002 4 ]
A ring-shaped protrusion 46 is provided on a portion of the motor body 26 located on the outer periphery of the rear bracket 32. The ring-shaped protrusion 46 is provided with the position detection element 24 protruding from the control board 18.
[002 5 ]
A control IC 18 located behind the rear bracket 32 is provided with a drive IC that is vulnerable to heat and an electronic component 22 that dissipates much heat.
[002 6 ]
In the motor body 26, a support hole 34 formed by a projection for supporting the rear bracket 32 by a molding die when the rear bracket 32 is molded is formed at the rear of the rear bracket 32. That is, when the motor body 26 of the molded motor 10 is molded, a pin is provided at the center portion of a molding die (not shown), and the rear bracket 32 is supported by this pin. In order to allow this protrusion to penetrate, a through hole 20 penetrates through the central portion of the control board 18. The diameter φdB of the through hole 20 is the same as the size of the pin.
[002 7 ]
In the rotor 28, a rotation shaft 38 passes through a shaft portion of a columnar yoke 36 on which steel plates are stacked, and a cylindrical magnet 39 is disposed on the outer periphery of the columnar yoke 36. The axial length of the cylindrical magnet 39 is longer than the axial length of the columnar yoke 36, and a bracket insertion space 40 is formed.
[002 8 ]
When the rotor 28 is inserted into the rotor insertion space 30, the rear bearing 42 is attached to the rear part of the rotating shaft 38, and the front bearing 44 is attached to the front part of the rotating shaft 38. Then, the rear bearing 42 is fitted into the rear bracket 32. In this case, the rear bracket 32 is inserted into the bracket insertion space 40 inside the cylindrical magnet 39.
[00 29 ]
After the rotor 28 is inserted into the rotor insertion space 30, a front bracket 48 made of iron or aluminum is placed on the front surface of the motor body 26, and the front bearing 44 is fixed by the front bracket 48.
[003 0 ]
The molded motor 10 can be assembled as described above.
[003 1 ]
In the case of the molded motor 10 of the present embodiment, the position detecting element 24 is arranged inside the magnet 39 of the rotor 28 and the rear bracket 32 is made of a ferromagnetic material such as iron, so that the magnetic permeability is high. The permeance of the magnet 39 is increased, that is, the magnetic resistance is decreased, and the magnetic flux density at the operating point of the magnet 39 can be increased. Further, the distance between the position detection element 24 and the winding 16 of the stator 12 is increased, and the position detection element 24 is not easily affected by the armature reaction. Accordingly, the reliability of the position detection element 24 is improved, and the accuracy of the position of the rotor 28 is improved by the high magnetic flux density.
[003 2 ]
Since the rear bracket 32 and the rear bearing 42 are inserted into the bracket insertion space 40 of the rotor 28, the total axial length LB of the mold motor 10 is the total axial length LA of the conventional mold motor 100 shown in FIG. It can be made shorter and the motor can be reduced in size. Further, since the total length of the motor is shortened, the inertia can be reduced and the weight can be reduced.
[003 3 ]
It is only necessary to provide a through hole 20 having a diameter φ dB for passing a pin of the molding die in the central portion of the control board 18, the effective area SB of the control board 18 is increased, and the material removal of the board is improved. Compared with the diameter φdA of the through hole 128 of the mold motor 100 of the conventional example, φdA> φdB. Therefore, the effective area SB of the mold motor 10 of this embodiment is larger than the effective area SA of the conventional mold motor 100. For example, φdB = 4 mm to 5 mm.
[003 4 ]
Since the electronic component 22 is provided behind and around the rear bracket 32 with good heat dissipation of iron or the like and low thermal resistance, heat generation can be promoted and heat generation of the electronic component 22 itself can be suppressed. Therefore, the electronic component 22 and the like can be hardly subjected to restrictions due to heat, and characteristics such as output increase can be improved.
[003 5 ]
The electronic component 22 may be brought into direct contact with the rear bracket 32.
[003 6 ]
(Second Embodiment) A molded motor 10 according to a second embodiment of the present invention will be described with reference to FIG.
[003 7 ]
The difference between the present embodiment and the first embodiment is the shape of the control board 18.
[003 8 ]
That is, in this embodiment, the rear bracket 32 is fixed to the molding die by a magnet incorporated in the molding die, not by a pin. Therefore, it is not necessary to provide the through hole 20 at the center of the control board 18.
[00 39 ]
Therefore, the effective area of the control board 18 can be increased.
[004 0 ]
【The invention's effect】
With the molded motor of the present invention, the effective area of the control board can be increased.
004 1 ]
Further, the heat dissipation of the electronic component can be improved, the heat restriction on the electronic component is reduced, and the output can be increased.
[Brief description of the drawings]
FIG. 1A is a longitudinal sectional view of a molded motor showing a first embodiment of the present invention, and FIG. 1B is a plan view of a control board.
FIG. 2A is a longitudinal sectional view of a molded motor showing a second embodiment of the present invention, and FIG. 2B is a plan view of a control board.
3A is a longitudinal sectional view of a conventional mold motor, and FIG. 3B is a plan view of a control board.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Mold motor 12 Stator 14 Iron core 16 Winding 18 Control board 20 Hole 22 Electronic component 24 Position detection element 26 Motor main body 28 Rotor 30 Rotor insertion space 32 Rear bracket 34 Support hole 36 Yoke 38 Rotating shaft 38 Magnet 40 Bracket insertion Space 42 Rear bearing 44 Front bearing 46 Ring motor body 48 Front bracket

Claims (2)

A ring-shaped stator in which windings are wound around an iron core laminated with steel plates;
A control board that configures a drive circuit by arranging electronic components and position detection elements;
A rotor composed of a rotating shaft, a yoke and a cylindrical magnet;
A metal bracket disposed at the front and rear for attaching a bearing that rotatably supports the front and rear portions of the rotating shaft;
The stator, the control board, and the rear bracket are integrally molded, and a rotor insertion space is formed with mold resin inside the stator,
In the inner rotor type molded motor in which the rotor is arranged inside the stator by inserting the rotor into the rotor insertion space portion,
The rear bracket formed integrally with the mold resin is projected from the back of the motor body,
The rotor is formed such that the axial length of the magnet is longer than the axial length of the yoke,
The control board is arranged behind the rear bracket ;
A molded motor, wherein an electronic component disposed on the control board is disposed near a bottom surface of the rear bracket .   The ring-shaped protrusion is provided on the outer periphery of the rear bracket, and a position detection element protruding from the control board is disposed on the ring-shaped protrusion. Mold motor.

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