JPH04372547A - Electric motor - Google Patents

Abstract

PURPOSE:To easily fix a bracket to a stator core by engaging a pawl part, protrusively provided from the bracket, with an intermediate partition integrally provided with a surface premold. CONSTITUTION:Part of a peripheral surface, upper/lower surfaces, etc., except an internal peripheral surface of a stator core 10 mutually opposed to a rotor 12 are premolded by resin to cover the stator core 10, and a circular arc-shaped intermediate partition 52 is protrusively provided integrally with a premold in upper/lower surfaces of base parts of three pole pieces, protruded in an E shape toward the axial center, to fix a bracket 54 to the stator core 10 by engaging a pawl part 56, protrusively provided from the bracket 54, with the intermediate partition 52. Since the bracket 54 can be easily fixed to the stator core 10, work efficiency in a process of manufacture can be improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor in which windings are directly wound around a stator core, the stator core is molded, and a bracket is fixed to the molded stator core.

0002

[Prior Art] The present applicant first formed a ring-shaped yoke on the outer periphery, and provided a plurality of commutative poles protruding in the axial direction toward the inner circumference of the yoke, and a first winding part that projects from the yoke part in the axial direction; and an E-shaped axial center on the inner diameter side of the first winding part. A first winding is applied to this first winding part, and a first winding is applied to the first winding part, and a pole adjacent to the above-mentioned commutative pole of the tooth part is connected to the pole adjacent to the above-mentioned commutative pole. We proposed an electric motor in which a second winding is applied to the installed pole.

With this electric motor, when the first winding and the second winding are wound around the iron core, there are virtually no coil ends, and for example, when the output is 25 watts and the laminated thickness of the iron core is 25 mm, it is difficult to use a conventional motor. By comparison, the amount of copper wire is reduced by about 30%. Furthermore, as a result, copper loss is reduced, the amount of heat generated is reduced, and there is no coil end, as in a motor with toroidal winding around the yoke, so an extremely small induction motor can be formed. In addition, the first and second windings can be wound without dividing the iron core, and the magnetic flux density distribution in the air gap between the rotor and stator approaches a sine curve, resulting in less magnetic unevenness and less vibration. It is possible to obtain a small, quiet, and highly efficient induction motor, and it is extremely easy to manufacture.

0004

[Problem to be solved by the invention] In the above electric motor,
After the first winding and the second winding are wound, the stator core is molded with resin. A bracket is then fixed to this molded stator core.

However, conventionally, it has been difficult to fix a bracket to this molded stator, and various methods have been proposed. However. Regardless of the method, when fixing a metal bracket to a resin mold, the work process is complicated and other parts are used, which increases costs.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention uses an induction motor having the above-mentioned structure, in which a bracket can be easily fixed to a molded stator.

[0007]

[Means for Solving the Problems] The electric motor of the present invention has a stator core molded and a bracket fixed to the molded stator core, in which a ring-shaped yoke portion is formed on the outer periphery. It consists of a plurality of commutative poles protruding axially from the inner peripheral side of the yoke, and a main pole formed between the plurality of commutative poles, and the main pole is axially protruded from the yoke. A stator core is constituted by a first winding portion protruding from the first winding portion, and a tooth portion consisting of three poles protruding toward the axis in an E-shape on the inner diameter side of the first winding portion, A part of the outer peripheral surface of the stator core other than the inner peripheral surface facing the rotor, the upper and lower surfaces, etc., are pre-molded with resin to cover the stator core and protrude toward the axis in an E-shape. Arc-shaped septal walls are integrally provided on the upper and lower surfaces of the bases of the three poles together with the pre-mold, and claws protruding from the brackets are engaged with the septal walls,
The bracket is fixed to the stator core.

[0008]

[Operation] When the bracket is fixed to the stator core in the electric motor configured as described above, the claws protruding from the bracket are engaged with the septum wall integrally provided by pre-molding. This allows the bracket to be fixed to the stator core.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of the stator core 10.
FIG. 2 is a perspective view of the stator core 10.

In FIG. 1, a stator core 10 of an electric motor is formed by punching strip steel plates and laminating them in the required amount using a press. Six first winding portions 2 constituting a main pole protruding toward the axis 14 of the rotor 12 are equally arranged on the circumferential side.

A toothed portion 3 consisting of three poles 3a, 3b, and 3c is formed in an E-shape on the inner diameter side of the first winding portion 2.
The poles 3a, 3b, and 3c are formed to have the minimum necessary width as a magnetic path in order to minimize the volume of the stator core 10. Furthermore, the poles 3a and 3b are formed in an E-shape.
, 3c are formed on the inner diameter side of the first winding part 2, and therefore, like the first winding part 2, six tooth parts 3 are evenly arranged. Between this tooth part 3 and the adjacent tooth part 3,
A commutating pole 4 protrudes from the yoke portion 1 toward the shaft center 10 toward the inner diameter side.
Like the teeth 3, six pieces are equally arranged.

The inner diameter sides of the poles 3a, 3b, 3c and the commutating pole 4 constituting the tooth portion 3 are formed in a series of circular arcs so as to face the outer circumferential surface of the rotor 12 which is disposed adjacently through a slight gap. It is formed. The rotor 12 is rotatably supported by a shaft (not shown), and forms a cage-shaped rotor 12 in which a secondary conductor is formed from an aluminum die cast on the iron core 10 .

Six grooves 8 are provided at equal intervals in the axial direction on the outer periphery of the yoke portion 1. This groove 8 is provided in a guide when the core plate constituting the stator core 10 is pre-molded and then attached to a winding machine.

A first winding 6 is wound around the first winding portion 2, and a pole 3c and a pole 3a provided via a commutating pole 4 are connected to each other.
A second winding 7 is wound between the two. The first winding 6 and the second winding 7 are both wound through both end faces of the stator core 10 in the stacking direction, and after the necessary amount of winding, the first winding 6 and the second winding 7 are It is continuously wound around the toothed portion 3. Then, when the six first windings 6 and the second windings 7 are wound in respective predetermined positions, the terminals of the windings are pulled out and connected to a power source and a capacitor (not shown). It is configured.

When winding the first winding 6 and the second winding 7, it is necessary to form an insulating layer in advance on the part of the stator core 10 where the windings come into contact, and to protect the mechanical structure of the stator core 10. In order to improve the mechanical strength, it is injected with a resin called pre-molding.

Next, details of the pre-molding of the stator core 10 will be explained based on FIGS. 3 to 10.

The resin used in this pre-mold is a thermoplastic resin, and since it becomes liquid-like at high temperature and high pressure, it can be easily injected into the mold, and the stator core 10 This resin spreads to every nook and cranny. Moreover, this thermoplastic resin contracts when the temperature of the thermoplastic resin falls from the curing start temperature (approximately 180° C.) to room temperature (approximately 40° C.).

The resin layer 16 is formed on the stator core 10 by pre-molding, as shown in the plan view of the pre-molded stator core 10 in FIG.
0, the groove 8 on the outer periphery of the yoke part 1, the outer wall of the first winding part 2, and the outer periphery of the toothed part 3 consisting of the poles 3a, 3b, and 3c are pre-molded to form a resin layer 16. It is formed. As a result, when the stator core 10 is pre-molded with resin, since it is a thermoplastic resin, it contracts during the time from the hardening start temperature to room temperature, tightening the stator core 10. Therefore, this tightening improves the mechanical strength of the stator core 10. The inner circumferential surface of the tooth portion 3 facing the rotor 12, that is, the inner circumferential surface of the stator core 10, is pre-molded and has no resin layer formed thereon. The thickness of the resin layer 16 formed by pre-molding is 0.4
The thickness is from mm to 0.7 mm.

Note that the upper surface of the stator core 10 refers to the upper surface of the shaft center 1.
Reference numeral 4 indicates a surface on which the bracket 54 of the stator core 10 is attached;

This pre-mold not only improves mechanical strength by simply covering the upper and lower surfaces of the stator core 10 with resin to form a resin layer, but also has the following features.

[0022] Reference numeral 50 is an outer partition wall. This outer partition wall 5
0 is from the upper and lower surfaces of the outer peripheral surface of the yoke part 1.
The resin layer 16 is integrally provided with the resin layer 16 by a mold. This outer partition wall 50 allows the first winding 6
When the second winding 7 is wound around the stator core 10, the winding can be protected without coming into contact with other parts. In addition, if the height of the outer partition wall 50 is made higher than the coil ends of the first winding 6 and the second winding 7, the stator cores 10 can be piled up, making it easier to wind the windings.

Reference numeral 58 denotes a fixing piece for fixing the end of the winding provided on a portion of the outer partition wall 50 (see FIG. 4). The fixing piece 58 projects from the upper surface of the outer partition wall 50, and has a recess 60 in its center for holding the winding end. By fixing the ends of the windings to the fixing pieces 58, it is possible to mechanize the end processing of the stator windings. In other words, if a winding is placed on the stator core 10 and left as is, the winding may loosen, but if the end of the winding is fixed to this fixing piece 58, the winding will not loosen. There's nothing to do.

The fixing piece 58 of this embodiment has a concave portion 60 to fix the end of the winding as shown in FIG. A structure may be adopted in which a concave portion for holding the winding wire is directly provided, or two fixing pieces are provided protrudingly at shifted positions, and the winding end portion is sandwiched between the shifted positions.

Reference numeral 66 denotes a septum wall 66 protruding from the lower surface of the stator core 10. The septal walls 66 are six arcuate partition walls that protrude along the lower surface of the base of the tooth portion 3, which is made up of E-shaped poles 3a, 3b, and 3c. The role of the septum wall 66 is to insulate the first winding 6 and the second winding 7, and the septum wall 66 prevents the first winding 6 and the second winding 7 from coming into contact with each other. There is no. In particular, since the septum wall 66 is formed in an arc shape, it has sufficient strength even when protruding from the lower surface of the stator core 10, and prevents the first winding 6 from falling toward the inner circumference. prevent.

Reference numeral 52 denotes a septum wall on the upper surface of the stator core 10. The septal wall 66 has an E-shaped pole 3a.
, 3b, 3c, and is a partition wall between the arc-shaped first winding 6 and the second winding 7, which is provided along the upper surface of the base of the toothed portion 3. The septal wall 52 projects higher than the septal wall 66,
When the electric motor is assembled, its upper end reaches the bracket 54. The bracket 54 is fixed to the stator core 10 by biting into the septum wall 52 a claw portion 56 protruding from the outer periphery of the bracket 54 made of a steel plate. In this case, since the pre-mold made of thermoplastic resin is softer than the resin of the housing mold that covers the entire electric motor, the claw portion 56 of the bracket 54 can be easily bitten into the pre-mold. That is, when the claw portion 56 of the bracket 54 is to bite into the septal wall 54, only the upper end of the septal wall 52 is heated by ultrasonic waves or the like to soften it.
Attach the claw portion 56 while it is still soft.

Reference numeral 68 denotes an internal partition wall for the main pole, which is provided in an arcuate manner at the tips of the poles 3a, 3b, and 3c. This main pole inner partition wall 68 is for preventing the second winding 7 from falling inward. Furthermore, as shown in the drawings, since it is formed in a slobe shape, the second winding 7 can be accommodated in a predetermined position.

Reference numeral 70 denotes a commutating pole inner partition wall provided at the tip of the commutating pole 4. This commutating pole inner partition wall 70 is also for preventing the second winding 7 from falling inward. The inner partition wall 70 for the commutator is also formed to become more sloping toward the inside, and is formed so that the second winding 7 is accommodated in a predetermined position.

Reference numeral 72 is a bushing integrally formed by pre-molding (see FIGS. 9 and 10). The bushing 72 includes a bushing main body 74 projecting from the outer periphery of the yoke 1 and a lid 76 rotatably provided on the main body 74. Then, at the base of the main body 74,
An insertion section 78 for inserting the ends of the first winding 6 and the second winding 7 is provided. When assembling this bushing 72, after soldering the ends of the first winding 6 and second winding 7 and the tip of the lead wire 80 of the lead wire, the soldered portion 82 is Insert into the insertion portion 78 and cover with the lid 76 (see FIG. 10).

[0030] Thereby, it is not necessary to attach only the bushing from the outside as in the conventional case, so that the assembly process can be simplified and costs can be reduced. In addition, when this bushing is integrally molded, by making the relay holding part and the connecting insulating part as an integrally molded product, it is possible to further reduce costs and improve work efficiency.

With the pre-molding of the stator core 10 having the above structure, the mechanical strength of the stator core 10 is improved by pre-molding, and the first winding 6 and the second winding are It is also possible to insulate the wire 7.

[0032]

[Effects of the Invention] According to the above, the electric motor of the present invention has
The bracket can be easily fixed to the stator core by engaging the claws protruding from the bracket with the septum wall integrally provided by pre-molding.

[0033] Therefore, work efficiency in the manufacturing process of the electric motor can be increased, and since no other parts are used, costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a plan view of a stator core.

FIG. 2 is a perspective view of the stator core.

FIG. 3 is a plan view of the stator core in a pre-molded state.

FIG. 4 is a partially enlarged perspective view of the stator core in a pre-molded state.

FIG. 5 is a sectional view taken along line AA in FIG. 3;

FIG. 6 is a sectional view taken along line BB in FIG. 3;

FIG. 7 is a half-longitudinal cross-sectional view of the electric motor.

FIG. 8 is an enlarged sectional view of a state in which the claws of the bracket are biting into the septal wall.

FIG. 9 is an enlarged perspective view of the bushing.

FIG. 10 is an enlarged sectional view of the bushing.

[Explanation of symbols]

1...Yoke part 2...First winding section 3...teeth part 3a, 3b, 3c...pole 4... Complementary pole 5...Rotor 12 6...First winding 7...Second winding 10...Stator core 12...Rotor 16...resin layer 50...Outer bulkhead 52...Septal wall 54...Bracket 56...Claw part 58... Fixed piece 60... recess 66...Septal wall 68...Inner partition for main pole 70... Inner partition wall for interpolation 72...Bushing 74...Bushing body 76...Lid body 78...Insertion part 80...Lead wire

Claims (1)

[Claims] Claim 1: An electric motor in which a stator core is molded and a bracket is fixed to the molded stator core,
A ring-shaped yoke is formed on the outer periphery, and consists of a plurality of commutative poles that protrude in the axial direction toward the inner circumference of the yoke, and a main pole formed between the plurality of commutative poles. A first winding part with a main pole protruding axially from the yoke part, and teeth consisting of three poles protruding toward the axis in an E-shape on the inner diameter side of the first winding part. A stator core is constructed from the parts, and a part of the outer peripheral surface of the stator core other than the inner peripheral surface facing the rotor, the upper and lower surfaces, etc. are pre-molded with resin to cover the stator core, and the stator core is covered with resin.
Arc-shaped septal walls are integrally provided with the pre-mold on the upper and lower surfaces of the bases of the three poles that protrude toward the axis in a letter shape, and the claws protruding from the bracket are attached to the septal walls. An electric motor characterized in that a bracket is fixed to a stator core by engaging with the bracket.