JP2012019569A - Electric motor and electric blower using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric motor that can improve manufacturing efficiency by reducing the number of components while maintaining necessary electric insulation in an armature.SOLUTION: An electric motor comprises: an armature core 1 fixed to a shaft 3; a plurality of teeth 2 that are provided on the armature core 1 and protrude radially from the armature core 1 centering the shaft 3; a coil 5 wound around the teeth 2 and disposed in a slot 4 between the teeth 2; and an annular body 6 in which a magnetic member 7 having the same number as that of the teeth 2 is integrated with a resin member 8 by insert molding. The magnetic member 7 is disposed on the same circumference so as to face each of the teeth 2 and its one-side face 7a forms a part of the inner peripheral surface of the annular body 6. Then, the annular body 6 is fixed to the teeth 2 by fitting the one-side face 7a of the magnetic member 7 into the tip face 2a of the teeth 2.

Description

  The present invention relates to an electric motor and an electric blower using the electric motor.

FIG. 10 is a cross-sectional view of a main part showing an armature of a conventional electric motor, and specifically shows the configuration of the armature described in Patent Document 1 below.
In FIG. 10, 14 is an armature core fixed to a predetermined shaft, and 15 is a plurality of teeth provided on the armature core 14. The teeth 15 have a predetermined length in the axial direction of the shaft, and are formed so as to protrude radially from the outer peripheral portion of the armature core 14. Reference numeral 16 denotes a slot formed of a space formed between adjacent teeth 15. A coil 17 wound around the tooth 15 is disposed in the slot 16.

  Reference numeral 18 denotes an annular body that covers the armature core 14 and the teeth 15. The annular body 18 is basically made of a magnetic material, and a nonmagnetic modified portion 18 a is provided at a portion facing the slot 16. A wedge 19 for maintaining electrical insulation between the coil 17 and the annular body 18 is disposed in the slot 16.

JP 2002-17060 A

  In the conventional electric motor, in order to maintain electrical insulation between the magnetic material portion of the annular body 18 and the coil 17, a wedge 19 made of an insulator has to be disposed in each slot 16. In recent years, there has been a problem that the number of the armature slots 16 tends to increase in the electric motor of the electric blower for a vacuum cleaner, and the presence of the wedge 19 increases the number of parts and significantly reduces the manufacturing efficiency.

  Furthermore, in recent years, there has been a demand for higher performance in electric motors for electric blowers for vacuum cleaners, and suppression of performance variations such as current and torque is required. Since the magnetic flux excited by the coil 17 forms a magnetic circuit through the teeth 15, high precision is required for their shape and dimensions. There has been a problem that the positional accuracy of the annular body 18 with respect to the core 14) tends to be lowered. Further, with the high performance of the motor, it is also required to increase the rotation speed of the armature, and between the annular body 18 and the teeth 15 (the armature core 14) due to acceleration / deceleration when the armature is started and stopped. Relative displacement sometimes occurred.

  The present invention has been made to solve the above-described problems, and its object is to improve manufacturing efficiency by reducing the number of parts while maintaining necessary electrical insulation in the armature. An electric motor that can be used, and an electric blower that uses the electric motor.

  Another object of the present invention is to improve the positional accuracy of the annular body with respect to the armature core and reliably prevent the relative displacement generated between the annular body and the armature core in the electric motor and the electric blower using the electric motor. And

  An electric motor according to the present invention includes an armature core fixed to a shaft, a plurality of teeth that are provided on the armature core and project radially from the armature core about the shaft, and are wound around the teeth. And an annular body in which the same number of magnetic members as the teeth are integrated with the resin member by insert molding, and the magnetic members are arranged on the same circumference so as to face each tooth. One side surface forms a part of the inner peripheral surface of the annular body, and the annular body is fixed to the teeth by fitting one side surface of the magnetic member and the tip end surface of the teeth.

  In addition, the electric motor according to the present invention is provided on one of the tip surface of the tooth and one side surface of the magnetic member, and on the other of the tip surface of the tooth and one side surface of the magnetic member, and the annular body is fixed to the tooth. And a convex portion that is disposed in the concave portion.

  The electric blower according to the present invention includes any one of the electric motors according to the above invention.

According to the present invention, in an electric motor and an electric blower using the electric motor, manufacturing efficiency can be improved by reducing the number of parts while maintaining necessary electrical insulation in the armature.
Furthermore, the positional accuracy of the annular body with respect to the armature core can be improved, and the relative displacement generated between the annular body and the armature core can be reliably prevented.

It is principal part sectional drawing which shows the armature of the electric motor in Embodiment 1 of this invention. It is a perspective view which shows the annular body of an armature. It is the A section enlarged view shown in FIG. It is principal part sectional drawing of the annular body shown in FIG. It is a perspective view which shows the magnetic member of an annular body. It is an external view which shows the armature of the electric motor in Embodiment 1 of this invention. It is an external view which shows the armature before mounting | wearing with an annular body. It is principal part sectional drawing which shows the armature before mounting | wearing with an annular body. It is principal part sectional drawing which shows the armature of the electric motor in Embodiment 2 of this invention. It is principal part sectional drawing which shows the armature of the conventional electric motor.

  In order to explain the present invention in more detail, it will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

Embodiment 1 FIG.
1 is a cross-sectional view of an essential part showing an armature of an electric motor according to Embodiment 1 of the present invention.
In FIG. 1, 1 is an armature core made of a magnetic material, 2 is a plurality of teeth provided on the armature core 1, and 3 is a shaft on which the armature core 1 is fixed. The teeth 2 have a predetermined length in the axial direction of the shaft 3 and are formed so as to project radially from the outer peripheral portion of the armature core 1 around the axis center of the shaft 3. For example, when this armature is used in a commutator motor for a vacuum cleaner, 12 or more teeth 2 are formed at equal intervals on the outer periphery of the armature core 1. In addition, D1 in a figure has shown the outer diameter of the teeth 2. FIG. That is, the tip end surface 2 a of the tooth 2 is formed by an arc drawn with a radius that is ½ times D1 with the axis center of the shaft 3 as the center.

  Reference numeral 4 denotes a slot formed of a space formed between adjacent teeth 2. A coil 5 is wound around each tooth 2, and a main part of the coil 5 wound around the tooth 2 is disposed in the slot 4.

  Reference numeral 6 denotes an annular body that covers the armature core 1 and the teeth 2 in the axial direction of the shaft 3. Hereinafter, the configuration and manufacturing method of the annular body 6 will be specifically described with reference to FIGS. 2 is a perspective view showing an annular body of an armature, FIG. 3 is an enlarged view of a portion A shown in FIG. 2, FIG. 4 is a cross-sectional view of a main part of the annular body shown in FIG. It is a perspective view.

  The annular body 6 has an annular shape (as a whole, a cylinder) having an outer diameter D2 having a predetermined length L1. The main part of the annular body 6 is constituted by the same number of magnetic members 7 as the teeth 2 and a resin member 8 made of a predetermined resin excellent in electrical insulation and heat resistance.

  The magnetic member 7 is integrated with the resin member 8 by insert molding, and is disposed at equal intervals on the same circumference so as to face each tooth 2 from the outside. Specifically, the magnetic member 7 is a rod-shaped member having a length L2 (<L1) having a substantially T-shaped cross section as shown in FIG. 7a is one side surface of the magnetic member 7 forming the bottom surface side of the T-shape, and 7b is the other side surface of the magnetic member 7 forming the top surface side of the T-shape. One side surface 7a of the magnetic member 7 is configured by an arc drawn concentrically with an arc that forms the outer diameter D1 of the tooth 2 and having a radius that is ½ times D1. The one side surface 7 a is formed so that its width (width in the circumferential direction of the annular body 6) is substantially the same as the width of the tip end surface 2 a of the tooth 2. Further, the other side surface 7 b of the magnetic member 7 is configured by an arc drawn with a radius that is ½ times D2 with the axis center of the shaft 3 as the center. The width of the other side surface 7b is larger than the width of the one side surface 7a in the axial length direction of the shaft 3.

  The magnetic member 7 having such a shape can be configured, for example, by stacking a predetermined number of thin electromagnetic steel plates having a thickness of 0.2 to 0.5 mm, and fixing and stacking each by welding or caulking. Further, the magnetic member 7 may be constituted by a single member by machining a predetermined magnetic material in the thrust direction to a predetermined thickness L2.

Then, the same number of magnetic members 7 having the above configuration as the teeth 2 are prepared, arranged at equal intervals on the same circumference, and the resin members 8 are combined by insert molding to complete the annular body 6. At this time, the entire one side surface 7a of the magnetic member 7 is exposed to the inside of the annular body 6 and the entire other side surface 7b is exposed to the outside, and a part of the inner circumferential surface of the annular body 6 is A part of the surface is formed by the other side surface 7b. Further, the entire surface of the magnetic member 7 except the one side surface 7a and the other side surface 7b is covered with the resin member 8, and the magnetic member 7 is firmly fixed to the resin member 8 and magnetic flux leakage is prevented. . For example, by making the length L 1 of the annular body 6 about 0.5 to 5 mm larger than the length L 2 of the magnetic member 7, both end surfaces of the magnetic member 7 are completely covered with the resin member 8.
As described above, the annular body 6 having the inner peripheral surface with the diameter D1 and the outer peripheral surface with the diameter D2 concentric with the inner peripheral surface is formed.

Next, the armature manufacturing method will be specifically described with reference to FIGS.
6 is an external view showing the armature of the electric motor according to Embodiment 1 of the present invention, FIG. 7 is an external view showing the armature before the annular body is mounted, and FIG. In the figure, 9 is a bearing that supports the shaft 3, 10 is an insulating member, 11 is insulating paper, and 12 is a commutator.

  In manufacturing the armature, first, the shaft 3 is tightly fitted and fixed to the armature core 1, and a member for electrical insulation is installed. Specifically, the two insulating members 10 are arranged from both sides of the armature core 1 so as to sandwich the armature core 1 from the axial direction. The insulating member 10 includes an end plate portion for maintaining electrical insulation between the armature core 1 and the coil 5 and a pipe portion for maintaining electrical insulation between the shaft 3 and the coil 5. In addition, an insulating paper 11 is arranged in a U-shaped cross section along the side surface of the tooth 2 in the slot 4 to maintain electrical insulation between the armature core 1 and the coil 5.

  Next, the coil 5 is wound around the tooth 2 and disposed in the slot 4. Further, the annular body 6 is tightly fitted to the teeth 2, and the annular body 6 is firmly fixed to the teeth 2 (armature core 1). At this time, the annular body 6 is aligned so that each one side surface 7a of the magnetic member 7 is in contact with each tip surface 2a of the tooth 2 and the width of the one side surface 7a matches the width of the tip surface 2a. 3 to push the annular body 6 in the axial direction. Thereby, the annular body 6 is fixed to the tooth 2 (armature core 1) by fitting the one side surface 7a of each magnetic member 7 and the tip end surface 2a of each tooth 2, and the armature having the cross section shown in FIG. Is completed.

  If it is an electric motor provided with the armature of the said structure, manufacturing efficiency can be improved by reducing a number of parts, maintaining required electrical insulation in an armature. For this reason, adopting such an electric motor can be a particularly effective means in an electric fan for a vacuum cleaner in which the number of slots 4 tends to increase. In addition, although the rotational speed of the armature is increasing in the electric blower for a vacuum cleaner, the holding strength of the magnetic member 7 is sufficiently secured by insert molding, so the annular body 6 is destroyed by the rotation of the armature. There is no fear.

Embodiment 2. FIG.
FIG. 9 is a cross-sectional view of a main part showing the armature of the electric motor according to Embodiment 1 of the present invention.
The armature of the motor in the present embodiment is provided with a fitting portion for determining the position of the annular body 6 with respect to the tooth 2 (armature core 1). Other configurations are the same as those shown in the first embodiment.

  The fitting portion includes, for example, a concave portion 13 a provided in the tooth 2 and a convex portion 13 b provided in the annular body 6. Specifically, the concave portion 13 a is formed of a semicircular depression formed in the distal end surface 2 a of the tooth 2. Moreover, the convex part 13b consists of a semicircle-shaped protrusion formed in the one side surface 7a of the magnetic member 7, and when the annular body 6 is appropriately fixed to the teeth 2, it is arranged in the concave part 13a. Is formed.

  In addition, the said fitting part may be provided in the one part among the teeth 2 and the magnetic member 7 which are paired, and may be provided in all. Further, the concave portion 13 a may be formed on one side surface 7 a of the magnetic member 7, and the convex portion 13 b may be formed on the distal end surface 2 a of the tooth 2.

  As in the case of the first embodiment, the magnetic member 7 having the above shape is formed by, for example, laminating a predetermined number of thin magnetic steel sheets of 0.2 to 0.5 mm or machining a predetermined magnetic material. Composed. Then, the same number of magnetic members 7 as described above are prepared as the teeth 2 and arranged on the same circumference at equal intervals, and the resin members 8 are combined by insert molding to complete the annular body 6.

  In manufacturing the armature, the shaft 3 is tightly fitted and fixed to the armature core 1, and then the insulating member 10 and the insulating paper 11 are appropriately disposed to ensure predetermined electrical insulation. Further, the coil 5 is wound around the tooth 2 and disposed in the slot 4, and the annular body 6 is closely fitted to the tooth 2, so that the annular body 6 is firmly fixed to the tooth 2 (armature core 1). At this time, the position of the annular body 6 in the radial direction is determined on the basis of the position of the fitting portion, each side surface 7a of the magnetic member 7 is in contact with each tip surface 2a of the tooth 2, and (fitting portion When there are a plurality of the annular bodies 6, the annular body 6 is pushed in the axial length direction of the shaft 3 so that all the convex portions 13 b are arranged in the recessed portions 13 a, and the annular body 6 is tightly attached to the teeth 2 (armature core 1) Fit.

In the armature having the above configuration, the radial position of the annular body 6 can be determined based on the position of the fitting portion. Moreover, when the position of the annular body 6 has shifted | deviated, the convex part 13b is not accommodated in the recessed part 13a, and the annular body 6 cannot be attached to the teeth 2 (armature core 1). For this reason, if it is an electric motor provided with the armature of the said structure, the positional accuracy of the annular body 6 with respect to the teeth 2 (armature core 1) can be improved reliably. Further, the fitting portion can sufficiently secure the holding strength in the circumferential direction of the annular body 6, and between the annular body 6 and the armature core 1 when the armature is started and stopped. There is no risk of relative displacement.
The other effects are the same as those in the first embodiment, and the present electric motor can be a particularly effective means in the electric fan for a vacuum cleaner.

DESCRIPTION OF SYMBOLS 1,14 Armature core 2,15 Teeth 2a Tip surface 3 Axis 4,16 Slot 5,17 Coil 6,18 Annular body 7 Magnetic member 7a One side 7b Other side 8 Resin member 9 Bearing 10 Insulating member 11 Insulating paper 12 Rectification Child 13a Concave part 13b Convex part 18a Nonmagnetic modified part 19 Wedge

Claims (6)

An armature core fixed to the shaft;
A plurality of teeth provided on the armature core and projecting radially from the armature core about the axis;
A coil wound around the teeth and disposed in a slot between the teeth;
An annular body in which the same number of magnetic members as the teeth are integrated with a resin member by insert molding,
With
The magnetic member is disposed on the same circumference so as to face each of the teeth, and one side surface forms a part of the inner circumferential surface of the annular body,
The electric motor according to claim 1, wherein the annular body is fixed to the teeth by fitting the one side surface of the magnetic member and a tip end surface of the tooth. A recess provided on one of the tip surface of the teeth and the one side surface of the magnetic member;
A convex portion that is provided on the other of the tip surface of the tooth and the one side surface of the magnetic member, and is disposed in the concave portion when the annular body is fixed to the tooth;
The electric motor according to claim 1, further comprising:   The one side surface of the magnetic member is arranged such that a circumferential width of the annular body coincides with a width of the tip end surface of the teeth over an axial length direction of the shaft. The electric motor according to claim 1 or claim 2.   2. The magnetic member according to claim 1, wherein the other side surface forms a part of the outer peripheral surface of the annular body, and the entire surface other than the one side surface and the other side surface is covered with the resin member. The electric motor according to claim 3.   5. The electric motor according to claim 4, wherein the magnetic member has a circumferential width of the annular body that is larger on the other side than on the one side.   An electric blower comprising the electric motor according to any one of claims 1 to 5.

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