JPH05260705A - Manufacture of motor rotor - Google Patents

Abstract

PURPOSE:To obtain a motor rotor having a core with uniform magnetic flux distribution by manufacturing them so that marks of laser welding of a specified depth formed on the sides of the core teeth of the core may be removed in the grinding work of the peripheral surfaces of the cores. CONSTITUTION:Core sheets 4 having a large number of core teeth 6 in the peripheral directions are made by punching a thin belt plate with a punching device, and a specified number of these core sheets 4 are laminated so that the core teeth 6 may meet at an angle with the direction of the axis and may be parallel to one another. Then, a core 3 is produced by welding core sheets 4 adjoining one another at the peripheral surfaces of arbitrary core teeth 6 by a specified welding depth A with a laser welding device. And after rotating shaft 1 is inserted into the core 3 with pressure, coils 7 are wound on the core teeth 6, and the whole armature 2 is coated with epoxy resin 11. After that, weld marks 12 are removed by grinding the peripheral surface of the cores 3 by a grinding depth B deeper than the welding depth A with a lathe, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a motor rotor, and more particularly to a method for manufacturing a motor rotor characterized by a core stacking method.

[0002]

2. Description of the Related Art Conventionally, in the process of manufacturing a motor rotor, when manufacturing a stratified core forming an armature, a core tooth 6 adjacent to a core tooth 6 as shown in FIG. Slot 5 formed between
The core sheet 4 in the form of a hollow disc having the following is punched by a punching device (not shown), and at this time, four punching projections 31 are provided on the core sheet, and the punching projections for joining the adjacent core sheets 4 A method is known in which the core sheets 4 are pressure-laminated by fitting 31 together.

Further, Japanese Patent Application Laid-Open No. 3-253247 discloses a method for producing a laminated core by irradiating a core sheet with a laser beam and spot welding adjacent core sheets at their side edge portions. ing.

However, in these conventional methods, in the former method, the core sheets 4 are electrically coupled together with the mechanical coupling by the convex portions 31, so that the alternating magnetic field is generated. Is increased, the efficiency of the motor is reduced, and the magnetic flux density of each tooth of the core is not uniform due to the presence of each convex portion 31, which causes a problem that cogging occurs in the motor. is there. The same problem occurs in the latter case.

[0005]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, a main object of the present invention is to provide a method for manufacturing a motor rotor which has high efficiency and does not cause cogging.

[0006]

According to the present invention, the object is to stack a plurality of hollow disk-shaped core sheets having a plurality of slots and a plurality of teeth in the axial direction, and A process in which the teeth side edges extending in the axial direction of the laminated core sheets are laser-welded with a predetermined welding depth, and the core sheets are laminated and integrated into a rotating shaft. It has a step of coaxially press-fitting, a step of winding a coil around the core so as to pass through the slot, and a step of cutting the outer peripheral surface of the core deeper than the welding depth. It is achieved by providing a method for manufacturing a motor rotor.

[0007]

With this arrangement, the laser welding mark having a predetermined welding depth formed on the core teeth side edge of the core is cut off when the outer peripheral surface of the core is cut, so that the magnetic flux distribution is uniform. It is possible to manufacture a motor rotor having various cores.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a diagram showing a motor rotor to which a manufacturing method according to the present invention has been applied, with a part of the resin coating layer removed. Are spaced apart and fixed so as to be coaxial with each other. The armature 2 has a core 3 formed by stacking the core sheets 4 shown in FIG. 2 in a substantially axial direction, and 31 pieces divided along the circumferential direction by 31 slots 5 extending in the substantially axial direction. It has 6 core teeth.

As shown in FIG. 3, the slots 5 and the core teeth 6 formed in the core 3 form an angle with respect to the axial direction and the slots and the core teeth are parallel to each other. Is formed in. Further, the armature 2 has a plurality of coils 7 wound around the core teeth 6 so as to pass through the slots 5.

The commutator 8 fixed to the left side of the rotary shaft 1 in the drawing is formed at 31 end segments 9 which are divided in the circumferential direction so as to be insulated from each other, and an end portion on the armature 2 side. It has 31 engaging grooves 10 a formed in the expanded diameter portion 10. The lead wire 7a of the coil 7 is connected to these engaging grooves 10a and fixed to each other. Then, the epoxy resin 11 is coated so as to cover the armature 2 and the expanded diameter portion 10.

Next, the main part of the process of manufacturing the motor rotor of FIG. 1 will be described with reference to the block diagram shown in FIG.

First, in step 21, it is formed in the gap between the core teeth 6 extending in the radial direction and the core teeth 6 adjacent to each other from the strip-shaped thin plate by a punching device (not shown) as shown in FIG. The core sheet 4 having the strulo 5 is punched out. This punching device is of a known type and comprises an upper die having a punch for punching the shape of the core sheet 4 and a lower die having a die into which the core sheet 4 is pulled out. Then, in step 22,
A predetermined number of punched core sheets 4 are laminated so that the slots 5 and the core teeth 6 form an angle with respect to the axial direction and the slots and the core teeth are parallel to each other. At this time, the outer peripheral surfaces of the arbitrary core teeth 6 of the 31 core teeth 6 extending in the axial direction are adjacent to each other with a predetermined welding depth A (shown in FIG. 4) by a laser welding device (not shown). The core 3 is obtained by welding the core sheet 4.

Next, in step 23, the core 3 is attached to the rotary shaft 1.
Coaxially insert and press fit. Then, in step 24, the entire surface of the core 3 is coated by melting and fixing the epoxy resin powder by a known electrostatic cloud method or a powder coating method such as a fluid immersion method. Then, in step 25, the coil 7 is wound around the core tooth 6 so as to pass through the slot 5, and the lead wire 7 a of the coil 7 is electrically charged into the 31 engagement grooves 10 a formed in the expanded diameter portion 10. Stick to each other by wearing. In step 26, epoxy resin 11 is coated on the entire armature 2 so that the slot 5 is also filled with resin and the coil 7 is held. Finally, in step 27, the outer peripheral surface of the core 3 thus formed is cut by lathing or the like. At this time, as shown in FIG. 4, the outer peripheral surface of the core 3 is cut with a cutting margin B that is deeper than the welding depth A described above.

In step 22, the motor rotor manufactured by the above-described manufacturing method has a welding mark 12 having a predetermined welding depth A extending along the axial side edge of the core teeth 6 of the core 3. Since it is cut off in step 27, it becomes a rotor of a motor in which eddy current does not increase and cogging torque does not occur unlike the conventional case. Moreover, since the welding is laser welding, it can be applied to the outer peripheral surface of the core teeth 6 having a narrow width, and the welding depth A
Can also be smaller. Furthermore, the cutting process is the core 3
This is a process that is usually performed when a highly efficient motor is manufactured in order to obtain the outer diameter accuracy of (1) and reduce the air gap with the stator, and the number of processes is not increased.

Needless to say, the present invention is not limited to the above-mentioned embodiment and various applications are possible. For example, in this embodiment, epoxy resin is applied to the coating for the core and the coating for holding the coil. However, other synthetic resins may be used. Further, in the present embodiment, the resin coating is carried out in order to hold the coil in the step 26, but it is also possible to provide a coil stay made of a plate member.

[0016]

As is apparent from the above description, according to the method of manufacturing a motor rotor of the present invention, a core formed by laminating core sheets parallel to the direction of magnetic flux can be manufactured. It is possible to obtain a core in which the current does not increase and the magnetic flux distribution is uniform, cogging does not occur in the motor including the motor rotor having this core, and the efficiency is high. Therefore, the motor rotor to which the manufacturing method according to the present invention is applied is suitable for, for example, an electric power steering motor or the like that requires stable rotation torque.

[Brief description of drawings]

FIG. 1 is a perspective view showing a motor rotor to which a manufacturing method of the present invention is applied, with a resin coating layer partially removed.

FIG. 2 is a front view showing a core sheet forming a core of the motor rotor shown in FIG.

3 is a side view showing a core of the motor rotor shown in FIG. 1. FIG.

FIG. 4 is a partial longitudinal end view of the core taken along line IV-IV of section D shown in FIG.

FIG. 5 is a block diagram schematically showing a method for manufacturing a motor rotor according to the present invention.

FIG. 6 is a front view showing a conventional core sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotating shaft 2 armature 3 core 4 core sheet 5 slot 6 core teeth 7 coil 8 commutator 9 segment 10 expanded diameter portion 11 epoxy resin 12 welding mark 21 to 27 process 31 stamped protrusion

Claims (1)

[Claims] 1. A process of stacking a plurality of hollow disk-shaped core sheets having a plurality of slots and a plurality of teeth in the axial direction, and the teeth side extending in the axial direction of the stacked core sheets. A process of laser welding the edge with a predetermined welding depth, a process of coaxially inserting and pressing the core obtained by laminating and integrating the core sheets into a rotary shaft, and a process of passing through the slot. And a step of winding a coil around the core and a step of cutting the outer peripheral surface of the core deeper than the welding depth.