JPH08266020A - Manufacture of stator assembly - Google Patents

Abstract

PURPOSE: To provide a method of manufacturing a motor in which a manufacturing process requiring high-accurate work in the part that a stator core is fitted into a motor case and a preliminary process of laminating and fixing magnetic steel plates can be eliminated. CONSTITUTION: A magnetic steel plate 12 is laminated into molding dies 20, 22 and pressed by the end-surface aiding die 20 to remove the burr of the magentic steel plate 12. A molten metal is poured into a cavity 24 surrounded by the molding dies 20, 22 and the laminated steel plate 12 to insert the laminated magnetic steel plate. Therefore, since shrinkage fitting is eliminated, high- accurate work is not required. Since the burr of the steel plate 12 is removed by the die fastening force of the aiding die and the steel plate is fixed by insertion, the process of removing a burr which is adopted as a preliminary process and also a welding process can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a motor, and more particularly to a method of manufacturing a stator assembly including a stator that forms a rotating magnetic field.

[0002]

2. Description of the Related Art Generally, a method of manufacturing a motor is completed by assembling a stator assembly including a cylindrical stator that forms a rotating magnetic field and a rotor assembly including a rotor that rotates inside the stator. .

FIG. 6 is a process diagram of a conventional motor manufacturing method. (A) shows a stator core 5 made by laminating a plurality of magnetic steel plates 50 and welding a part of the outer peripheral portion thereof.
2 is shown. Each of the magnetic steel plates 50 has a substantially annular plate shape, and when formed as a stator core, a convex portion 54 that serves as a magnetic pole and a concave portion 56 that serves as a slot portion into which a coil is inserted are formed on the inner peripheral portion thereof. They are formed alternately. Further, a concave portion 55 serving as a key groove is provided on the outer peripheral portion.
When laminating the magnetic steel plates 50, pressure is applied in the axial direction at a predetermined pressure to remove burrs remaining on the steel plate end faces, and the magnetic steel plates 50 are brought into close contact with each other. After that, the outer peripheral portion is welded. A conductor wire is inserted into the slot 56 of the stator core 52 to form a coil 58, and a stator 60 is formed as shown in FIG. Further, the outside of the stator 60 is covered with a case 62 as shown in (c). Case 62
Is a cylindrical portion 62 having cooling fins 64 provided on the outer periphery.
a and a side cover portion 62b provided at one end of the cylindrical portion, and a hole 62c through which the rotor shaft later passes is provided at the center of the side cover portion 62b. When housing the stator 60 in the case 62, heat shrinking is performed by heating and expanding the case 62 and inserting the stator 60 therein. In addition, a keyway 63 is provided on the inner surface of the cylinder.
Are provided, are aligned with the key groove 55 of the stator described above, and are positioned by the key 65. In this way, the stator assembly is created.

On the other hand, the rotor side is created as follows. First, as shown in FIG. 6D, the rotor shaft 70 is inserted into the rotor 68 in which the permanent magnets 66 are arranged at predetermined intervals on the outer circumference. Bearings 72 are arranged near both ends of the rotor shaft 70. Next, as shown in (e), the side cover 74 is attached to one end of the rotor shaft 70, and the rotor assembly is created.

The stator assembly and the rotor assembly described above are joined as shown in FIG. 3F to complete the motor.

[0006]

In the conventional method of manufacturing a motor as described above, the stator 60 and the case 6 are used.
In order to bond the two, the shrink fitting process is performed as described above. The shrink fitting process is a process of assembling by utilizing the thermal expansion and contraction of the material, and since the amount of deformation due to this heat is small, a high precision of processing is required for the fitting portion of the assembled parts. For example, if the shrinkage fit becomes large, it may not be possible to assemble the stator 60 and the case 62. On the contrary, if the shrinkage fitting margin is not sufficient, the fit may loosen due to heating during motor operation. The fitting part like this,
That is, the outer surface of the stator 60 and the inner cylindrical surface of the case 62 need to be machined with high precision, which causes a problem of high machining cost.

When the shrink fit allowance between the stator 60 and the case 62 is not sufficient, the stator 60 does not run idle due to the key 65 described above, but the contact between the stator 60 and the case 62 becomes insufficient, and the stator 60 cannot There was a problem that the generated heat could not be sufficiently transferred to the case and the cooling performance deteriorated.

The present invention has been made to solve the above-mentioned problems, and it is possible to secure the close contact between the stator and the case of the motor, shorten the manufacturing process, and reduce the manufacturing cost. The purpose is to provide a method.

[0009]

In order to achieve the above-mentioned object, a method of manufacturing a motor according to the present invention comprises a step of laminating magnetic steel sheets at a predetermined position in a cavity of a casting die, and pouring into the casting die. And a casting step of manufacturing a case-integrated stator core, which is formed by casting hot water and laminating the laminated magnetic steel sheets.

Further, in the above-described motor manufacturing method, fins may be formed on the outer peripheral portion of the case-integrated stator core in the casting step.

Further, in the above-described method for manufacturing a motor, the magnetic steel plate may be provided with a convex portion serving as a rotation preventing projection on the outer peripheral portion.

Further, in the above-described motor manufacturing method, the boundary surface between the case of the integral stator core and the magnetic steel plate may have an uneven shape for increasing the contact area.

[0013]

The present invention has the above-mentioned structure, and by shrink-casting the stator core, the shrink fit process can be eliminated. Therefore, high accuracy is not required for the outer surface of the stator core and the inner cylindrical surface of the case. Further, since the magnetic steel plate can be pressed by the casting die, it is not necessary to separately provide a step for deburring. Further, since the laminated magnetic steel sheets are cast around, it is not necessary to weld them in advance and integrate them.

Further, in the casting process, the radiation fins can be formed on the outer peripheral portion of the case-integrated stator core.

As described above, the step of welding the magnetic steel sheets can be omitted, and deburring of the magnetic steel sheets, stacking and fixing, case preparation, and formation of heat radiation fins can be performed simultaneously in the casting step.

Furthermore, by surrounding the magnetic steel sheet having the convex portion on the outer peripheral portion, it is possible to prevent the magnetic steel sheet (stator) from idling in the case. This allows the key to be abolished.

Further, by encircling the magnetic steel sheet having the irregularities on the outer peripheral portion, the contact area between the magnetic steel sheet (stator) and the case is increased, and the heat generated by the magnetic steel sheet is quickly transmitted to the case. You can

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an outline of the manufacturing process of the motor of this embodiment. FIG. 1 (a) shows a case-integrated stator core 10 formed by casting laminated magnetic steel sheets. FIG. 2 shows the stator core 10
FIG. 6 is an explanatory diagram of a manufacturing process of. As shown in FIG. 3, the magnetic steel plate 12 has an annular disc shape, and irregularities are alternately provided on the inner periphery thereof. When the layers are formed as a stator by stacking, the recesses 14 serve as slots for accommodating coil conductors, and the projections 16 serve as magnetic poles. Further, a convex portion 18 serving as a rotation preventing protrusion is provided on the outer peripheral portion.

As shown in FIG. 2, the magnetic steel plates 12 are laminated and arranged in the casting molds 20 and 22. The casting mold is the end face mold 2
0 and side mold 22. The magnetic steel plates 12 are put into the tip portion 20a of the end face die 20 and sequentially laminated. A groove (not shown) is formed in the end surface type front end portion 20a along the cylindrical axis direction when the stator is formed, and the front end of the convex portion 16 of the magnetic steel plate 12 is engaged with this groove. The magnetic steel sheet is positioned in the circumferential direction. As a result, the magnetic steel plates 12 are stacked, and when the stator core is formed, the recesses 14 and the protrusions 16 are aligned to form slots and magnetic poles extending in the axial direction of the cylinder. Further, the convex portions 18 on the outer peripheral portion are laminated so as to be aligned.

Then, the magnetic steel plates 12 laminated by the end face mold 20 are pressed in the axial direction of the cylinder to remove the burrs remaining on the end faces of the steel plates 12 to bring the steel plates 12 into close contact with each other.

The side surface mold 22 is provided with irregularities for forming a fin shape on the outer peripheral portion of the case.

A cavity 24 is formed by the casting molds 20 and 22 and the magnetic steel plate 12 described above. Molten metal (hot water) is poured into this cavity, and the steel plate 12 is in a state of being surrounded. This hot water is a metal having a relatively low melting point and a good hot water flow, so-called good castability, and a metal having good thermal conductivity is used to dissipate the heat generated in the magnetic steel plate 12 during motor operation. Is preferred, and an aluminum alloy is used in this embodiment.

Through the above-described casting process, deburring of magnetic steel sheets, lamination and integration of magnetic steel sheets, and formation of fins 26 for heat dissipation are performed. Further, the convex portion 18 provided on the outer peripheral portion of the magnetic steel plate 12 is cast around to function as a rotation preventing protrusion. As described above, the case-integrated stator core 10 in which the laminated magnetic steel plates 12 are cast in the case 28 is produced.

Next, as shown in FIG. 1B, the coil 30 is formed on the case-integrated stator core 10, and the side cover 32 is assembled as shown in FIG. The side cover 32 is provided with a through hole 36 through which the rotor shaft penetrates and a bearing receiving portion. In this way, the stator assembly 34 is completed.

On the other hand, the rotor side is assembled in a conventional manner as shown in FIGS. 1 (d) and 1 (e). Since this is the same as the conventional one, its explanation is omitted. Then, the rotor assembly 76 is inserted into the above-mentioned stator assembly 34 to complete the motor.

According to the above embodiments, the casting molds 20 and 22 are
The magnetic steel plate 12 can be deburred and brought into close contact with the mold clamping force, and there is no need to provide a separate pressurizing step. Further, since the magnetic steel plates 12 are laminated and fixed, the step of welding the outer peripheral portion is not required. Furthermore, according to the present embodiment, the high precision required for processing the inner cylindrical surface of the case 62 and the outer surface of the stator 52 in the related art is not required, and the processing cost can be reduced. Further, the key 63 can be eliminated by providing a rotation preventing protrusion. Furthermore, since the magnetic steel plate 12 and the case 28 are in complete contact with each other, good heat dissipation can be obtained.

According to the above-described embodiment, the outer surface of the laminated magnetic steel plates 12 has the protrusion 18 for preventing the rotation by the protrusion 18.
Although it is a fully formed cylinder, as shown in FIG. 4, magnetic steel sheets 112 and 113 having two kinds of outer diameters are prepared and alternately laminated by a predetermined number to increase the contact area with the case 28. be able to. The magnetic steel plates 112 and 113 are also provided with rotation preventing protrusions 118. In the case of this embodiment, it is possible to obtain the same effect as that of the above-described embodiment, and particularly, it is possible to obtain better characteristics in terms of heat dissipation.

Further, as shown in FIG. 5, a plurality of convex portions 219 can be arranged on the outer circumference of the magnetic steel plate 212 to increase the contact area with the case 28. In this case, this convex portion 2
19 also serves as a rotation stop protrusion. Also in the case of this embodiment, the same effect as that of each of the above-mentioned embodiments can be obtained, and particularly good characteristics can be obtained in terms of heat dissipation.

[0029]

As described above, according to the present invention, by shrinking the stator core, the shrink fit process can be eliminated, and high accuracy is not required for the outer surface of the stator core and the inner cylindrical surface of the case. . As a result, it is possible to reduce the processing cost by high-precision processing.

Further, since the magnetic steel plate can be pressed by the casting mold, it is not necessary to additionally provide a step for deburring. Further, since the laminated magnetic steel sheets are cast around, it is not necessary to weld them in advance and integrate them. By eliminating these steps, the total number of strokes can be reduced.

Further, in the casting process, the radiation fins can be formed on the outer peripheral portion of the case-integrated stator core.

As described above, the step of welding the magnetic steel sheets can be eliminated, and deburring of the magnetic steel sheets, stacking and fixing, case preparation, and formation of the heat radiation fins can be simultaneously performed in the casting step. Then, the total number of steps can be reduced, and the processing cost can be reduced.

Further, the magnetic steel plate (stator) can be prevented from idling in the case by casting the magnetic steel plate having the convex portion on the outer peripheral portion. As a result, the key can be eliminated and the cost of parts can be reduced.

Further, by encircling the magnetic steel plate having irregularities on the outer periphery, the contact area between the magnetic steel plate (stator) and the case is increased, and the heat generated by the magnetic steel plate is quickly transferred to the case. It is possible to obtain good heat dissipation characteristics.

[Brief description of drawings]

FIG. 1 is a process drawing of a motor manufacturing method that is an embodiment according to the present invention.

FIG. 2 is an explanatory diagram of a casting process of this example.

FIG. 3 is a diagram showing a shape of a magnetic steel plate that serves as a stator core of the present embodiment.

FIG. 4 is a diagram showing a shape of a stator core of another embodiment.

FIG. 5 is a diagram showing a shape of a stator core according to still another embodiment.

FIG. 6 is a process diagram of a conventional motor manufacturing method.

[Explanation of symbols]

10 Case-integrated stator core, 12, 112, 11
3,212 magnetic steel plate, 20,22 casting mold, 24 cavity, 26 fin, 28 case, 34 stator assembly, 76 rotor assembly.

Claims (4)

[Claims] 1. A method of manufacturing a stator assembly including a substantially cylindrical stator core formed by laminating magnetic steel plates and a case provided outside the stator core, wherein the stator assembly is provided at a predetermined position in a cavity of a casting mold. Manufacture of a stator assembly, comprising: a step of laminating magnetic steel sheets; and a casting step of pouring molten metal into the casting die to produce a case-integrated stator core in which the laminated magnetic steel sheets are cast. Method. 2. The method of manufacturing a stator assembly according to claim 1, wherein fins are formed on an outer peripheral portion of the case-integrated stator core in the casting step. 3. The method of manufacturing a stator assembly according to claim 1, wherein the magnetic steel plate has a convex portion serving as a rotation preventing projection formed on an outer peripheral portion thereof. 4. The method of manufacturing a stator assembly according to claim 1, wherein a boundary surface between the magnetic steel plate and the case of the case-integrated stator core has an uneven shape that increases a contact area. Method.