JPS6226256B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing an electric motor, and particularly to a method of manufacturing an electric motor having an end bracket made of a steel plate.

[Conventional technology]

Small electric motors that are mass-produced are required to be economical and use resources effectively, and various devices have been devised to meet these requirements.

In response to these demands, a method that is currently most widely used is one in which the stator core is held from both sides by end brackets equipped with bearing devices, as described in Japanese Utility Model Application No. 48-73705. ing.

[Problem that the invention seeks to solve]

The conditions required in such a case are as follows.

(1) Assembly is done by stacking parts from one direction.

(2) The radial axes of the stator and rotor are aligned,
No magnetic imbalance occurs during operation.

(3) Materials can be used effectively and resources can be saved.

Among these, the ease of assembly (1) is greatly influenced by how the lead wires are drawn out. Conventionally, there are many structures in which the lead wire must pass through a hole provided in the end bracket, and this is a bottleneck for one-way assembly.

Furthermore, in (2) above, the gap between the stator and rotor is small, and if this gap becomes non-uniform, magnetic noise will increase. To prevent this, there is a method of inserting something called a gap gauge into the gap between the stator and rotor and removing it after assembly is completed, but this gap gauge is formed from a thin plate of about 0.2 to 0.3 mm. As a result, they are prone to wear, breakage, etc., and maintenance of the assembly equipment requires a lot of effort.

Furthermore, effective use of the materials mentioned in (3) above means effective use of resources, and it is effective to form both the core and the end bracket from rectangular materials with as small dimensions as possible.

The purpose of the present invention is to solve the problems of the conventional ones as described above, and to be suitable for automatic assembly, to have a high degree of coaxiality between the rotor and stator, and to save resources by effectively utilizing materials. It is possible to provide a method for manufacturing an electric motor that can contribute to

[Technical means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a method for manufacturing an electric motor in which an end bracket having a cylindrical portion having a diameter D and a depth d is attached to the end of a stator core, and the end brackets 12, 12 are The length of one side is greater than the diameter D, and the (D+
A cylindrical part with a diameter D and a depth d is formed by drawing using a rectangular steel plate not exceeding 2d),
The four corners protruding from the depth d of the rectangular material are bent outward at right angles by press working to form protruding pieces 14, and these protruding pieces 14 are fitted with the cut-off portions 15 of the stator core 3 and the cut-off portions 15 of the stator core 3. Corner cut portions 14A and sides 16 that are continuous to this are formed so as to match the sides that are continuous to , and both ends of the stator core 3 are formed so that these projecting pieces 14 are aligned with the four corners of the stator core 3, respectively. End bracket 12 on each side,
Each side of the end bracket 12 and the side of the stator core 3 are made by pressing the rectangular steel plate material with the above-mentioned dimensions into contact with each other and tightening and fixing both with screws as described above. In this method, a gap 20 is formed between 6 and 7, and the lead wire can be taken out from the gap 20.

[Effect]

According to the above method, in addition to the method of abutting the projecting piece of the end bracket against the end face of the stator core made of stacked many pressed silicon steel plates and fixing it with screws, etc., the lead wire is fixed to the end bracket. Since we adopted a method for taking out the lead wire from the gap formed between the child cores, the lead wire can be taken out between the protrusions, that is, from near the center of the side of the stator core, making it possible to stack and assemble from the axial direction. It improves the performance.

Additionally, the four corners of the stator core, including the cut-off portions, and the protrusions of the end bracket are made to have the same shape and are brought into contact with each other so that they match, so both can be stamped with high processing precision. Together, they work to align the radial axes of the stator and rotor, and as a result, work to reduce magnetic noise.

Furthermore, the end bracket is made of a rectangular steel plate in which the length of one side is larger than the diameter D and does not exceed (D + 2d), and by press working, there is inevitably a void in the part other than the part fixed to the stator core. occurs,
Since this gap can be used to take out the lead wire, there is no wastage of material and no resource loss occurs.

〔Example〕

Next, a configuration of an electric motor to which the present invention is applied and a method of manufacturing the same will be explained based on the drawings.

1 to 4, reference numeral 1 indicates an induction motor (hereinafter simply referred to as a motor) to which the method of the present invention is applied. 3 is a stator core around which coil 2 is wound, 4 is its inner peripheral surface, 5 is a slot,
6 and 7 are the two sides of the rectangle that forms the outer periphery,
In addition, 15 is a corner cutout having a function of regulating dimensions;
7 is a through hole.

8 is a rotor having a cylindrical outer peripheral surface 9;
10 is a gap between the stator core 3 and the inner circumferential surface 4, and 11 is a shaft.

Reference numeral 12 designates an end bracket having a U-shaped cross section, reference numeral 13 designates a bearing, reference numeral 14 designates a projecting piece that comes into contact with the cut-off portion 15 of the stator core 3, reference numeral 16 designates a right-angled side connected to this, and reference numeral 19 represents a through hole.

Further, 18 indicates a joint such as an assembly screw or rivet, 20 indicates a gap between the stator core 3 and the end bracket 12, and 21 indicates a lead wire.

That is, the electric motor 1 has a stator core 3 and a bearing 1.
It is sandwiched from both sides by end brackets 12 having a diameter of 3 to form a large structure.

The stator core 3 has a stator core 3 wound with a coil 2 from which a lead wire 21 is drawn out, and a plurality of coils 2 are wound around an inner circumferential surface 4 of the stator core 3. It has a slot 5. The stator core 3 is obtained by laminating steel plates having rectangular sides 6 and 7 formed by cutting a thin steel plate strip into a predetermined length, as shown in FIG. , At the four corners where the two sides 6 and 7 of this rectangle meet, a cut-off portion 15 (to be described later), end portions 6A and 7A of the sides 6 and 7 connected thereto, and a through hole 17 are formed. It is.

Further, the rotor 8 has a cylindrical outer peripheral surface 9, and the inner peripheral surface 4 of the stator core 3 has a gap 1 of 0.1 to 0.4 mm.
0 is separated, and a shaft 11 is fixedly fixed to the central portion thereof.

Further, as shown in FIG. 4, the end bracket 12 has a U-shaped cross section, which includes a cylindrical portion and a protruding piece 14 bent in four directions from the lower side of the cylindrical portion in an outward right angle direction. It has a bearing 13 in its center that rotatably supports the shaft 11, and as shown in FIG. It is something that you have.

Assuming that the diameter of the cylindrical portion of the end bracket 12 is D as shown in the figure, the diameter of the end bracket 12 is D or more (D
+2d) is obtained by press forming by drawing a steel strip with a side dimension not exceeding The projecting piece 14 is formed as it is at the corner of the stator core 3.
The corner cut portion 14A and sides 16, 16 having the same dimensions and joined to the corner cut portion 15 are formed concentrically with the bearing 13.

In this way, the stator core 3 and the end bracket 12 are both made of rectangular material, so that no material is wasted.

In particular, the end bracket 12 conventionally required at least a side dimension of (D+2d) or more, but as mentioned above, it has a side dimension of (D+2d).
For example, as shown in FIG. 1, by press-forming a band plate having a width of less than It is something that is inevitably formed.

This space 20 not only serves as a cooling ventilation path for the electric motor 1, but also can be used as a passage for the lead wire 21 drawn out from the coil 2. It does not require any process. Further, when assembling, the electric motor 1 can be formed by simply placing the stator core 3 on the end bracket 12, inserting the rotor 8 into the center of the stator core 3, and then placing another end bracket 12 on the stator core 3. In addition, in this case, the lead wire 21 can be automatically pulled out from the space 20 called h, which does not require any effort during assembly, and at the same time, automatic assembly from one direction is easy and possible. That is.

Furthermore, the projecting piece 14 of the end bracket 12
18, such as assembly screws or rivets.
A through hole 19 is provided.

With the respective configurations described above, the end bracket 12 and the stator core 3 are fixedly connected by the connecting body 18 through the respective through holes 19 and 17 using the above-described assembly method. , At this time, the two sides 6 of the rectangle of the stator core 3,
7 and the respective ends 6 of the end bracket 12
A and 7A are dimension regulating parts, and by aligning these parts from the outside with a jig or the like, the gap 10 between the rotor 8 and the inner diameter part 4 of the stator core 3 is maintained accurately, and the rotation is prevented. Eccentricity between child and stator,
That is, it is possible to prevent abnormal noise and vibration due to poor coaxiality.

As shown in the figure, semicircular recesses are provided on the rectangular sides 6, 7 of the stator core 3 and the sides 16, 16 of the end bracket 12, and for example, using these portions, as described above, Although alignment can be done from the outside using jig pins, etc., this is not limited to this shape, and it is also possible to use each edge part without using this. The dimensions can be regulated.

〔effect〕

As explained above, according to the method of the present invention,
The end brackets 12, 12 are made by drawing a cylindrical part with a diameter D and a depth d using a rectangular steel plate whose length on one side is larger than the diameter D and does not exceed (D+2d), and is made of a rectangular material. The four corners protruding from the depth d are each bent outward at right angles by press working to form protrusions 14, and these protrusions 14 include the cut-off portions 15 of the stator core 3 and the cut-off portions 15 connected thereto. Corner cut portion 14 to match the side
A and sides 16 connected thereto are formed, and end brackets 12, 12 are brought into contact with both end surfaces of the stator core 3, respectively, so that these projecting pieces 14 are aligned with the four corners of the stator core 3, respectively. At the same time, by tightening and fixing both with screws, and pressing a rectangular steel plate material having the above-mentioned dimensional relationship as described above, the distance between each side of the end bracket 12 and the sides 6 and 7 of the stator core 3 is Since the electric motor is manufactured by a method in which a gap 20 is formed and the lead wire is taken out from the gap 20, it is possible to stack and assemble from different directions, which improves work efficiency.

In addition, the four corners of the stator core, including the cut-off portions, and the protruding pieces of the end bracket are made into the same shape, and are pressed so that they match, so that the radial axes of the stator and rotor can be aligned. Magnetic noise is reduced.

Furthermore, the length of one side of the end bracket is D.
In the above, we used a rectangular steel plate that does not exceed (D + 2d) as a material, pressed it to form a gap in the area other than the part fixed to the stator core, and used this gap to take out the lead wire. This has the effect of completely eliminating waste of materials.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of an electric motor according to an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a schematic diagram of a stator core thereof, and FIG. 4 is an end bracket thereof. FIG. 1... Induction motor, 2... Coil, 3... Stator core, 4... Inner peripheral surface, 6, 7... Side, 6A, 7
A... end of side, 8... rotor, 9... outer peripheral surface,
10...Gap, 11...Shaft, 12...End bracket, 13...Bearing, 14...Protrusion piece, 14A...
... Corner cut part, 15... Corner cut part, 16... Side, 1
8...screw, 20...gap, 21...lead line.

Claims (1)

[Claims] 1 A rectangular stator core 3 whose outer circumferential diameter has sides 6 and 7 that are perpendicular to each other and has cut-off portions 15 at the four corners, and a coil wound in the slot 5 of the stator core 3. 2, and end brackets 12, 12 made of steel plates fixed to both end surfaces of the stator core 3 with screws 18 and having a cylindrical portion with a diameter D and a depth d.
, bearings 13, 13 respectively held by these end brackets, a shaft 11 rotatably supported by these bearings, and a shaft 11 that is attached to this shaft 11 and has a predetermined gap inside the stator core. In a method for manufacturing an electric motor comprising a rotor 8 arranged in a row, and a lead wire 21 drawn out from the coil through one of the end brackets, the end brackets 12, 1
2 is a rectangular steel plate whose length on one side is larger than the diameter D and does not exceed (D + 2d), and a cylindrical part with a diameter D and a depth d is formed by drawing, and the depth of the rectangular material is d. The four corners protruding from the top are bent outward at right angles by press working to form a projecting piece 14.
These projecting pieces 14 are formed with a corner cut portion 14A and a side 16 continuous thereto so as to match the corner cut portion 15 of the stator core 3 and the sides 6, 7 continuous thereto. End brackets 12, 12 are respectively brought into contact with both end surfaces of the stator core 3 so that the projecting pieces 14 of the stator core 3 are aligned with the four corners of the stator core 3, and both are tightened and fixed with screws. By pressing the rectangular steel plate material as described above, a gap 20 is formed between each side of the end bracket 12 and the sides 6 and 7 of the stator core 3.
1. A method of manufacturing an electric motor, characterized in that the lead wire can be taken out from zero.