JPH0353854B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides a stator core, in particular a stator composed of a stator core composed of thin plates made of magnetic material and a winding wound around the stator core, and a stator arranged opposite to the stator with a small gap therebetween so as to be rotatable. The present invention relates to a method of manufacturing a stator core for a small electric motor, which includes a rotor supported by a shaft. The method for manufacturing a stator core for a small electric motor of the present invention is a method for manufacturing a cylindrical stator core that is paired with a plate-shaped stator core to constitute the stator core for a small electric motor, and includes a thin plate of magnetic material. A cylindrical body with one end closed and a plurality of magnetic poles whose tips are closer to the outer periphery of the cylindrical body than the closed bottom surface are cut and raised and arranged concentrically with the cylindrical body, The diameter of the cylindrical body formed by this method is set to be larger than the sum of the inner diameter of the concentric circles of the magnetic poles and twice the length of the magnetic poles, and after cutting and forming the plurality of magnetic poles, the cylindrical body is It is characterized in that it is further embossed so that the outer diameter is smaller than the sum of the inner diameter of the concentric circle of the magnetic pole and twice the length of the magnetic pole. DESCRIPTION OF THE PREFERRED EMBODIMENTS Conventional embodiments and embodiments of the present invention will be described below with reference to the drawings. Figures 1 and 2 show a conventional small electric motor,
1 is a cylindrical stator core with one end closed, which is made of a thin plate made of magnetic material that also serves as the outer cover of the motor and the case of the reducer; 2 is a plurality of fixings from the closed end of the stator core. Hole left after cutting and raising the child magnetic pole, 3
are stator magnetic poles cut and raised from the hole 2 and arranged concentrically so as to be perpendicular to the end face and to maintain a constant gap length with respect to the outer circumference of the rotor; 4 is a winding frame of the stator winding; 5 is a winding frame of the stator winding; A stator winding, 6 is a plate-shaped stator core (hereinafter referred to as an S-ball plate) made of a thin plate made of magnetic material that pairs with the stator core 1, and 7 is a plate-shaped stator core made of a thin plate made of a magnetic material, which is cut and raised from the S-ball plate 6 at right angles, and is fixed to the above-mentioned. Magnetic poles that are alternately arranged on the same circumference as the child magnetic poles 3 and have a different polarity from the stator magnetic poles 3, 8 is the rotor shaft, 9 is the rear base plate of the reducer, 10 is also the front base plate, and 11 is the above-mentioned A rotor rotatably supported by a rotor shaft 8, 11
-1 is a pinion provided on the extended shaft of the rotor 11;
12 is an intermediate shaft of the reducer, 13 is an intermediate shaft gear fixed to this intermediate shaft 12, 14 is an output shaft bearing, 15 is an output shaft, 16 is an output shaft gear fixed to this output shaft 15, and 17 is an intermediate shaft gear fixed to this intermediate shaft 12. This is a pillar that connects the front and rear base plates 10 and 9. In the conventional small electric motor shown in FIG. An alternating magnetic field is generated in the magnetic poles 3 and 7, which are connected to the rotor 11 and arranged alternately on concentric circles facing each other with an air gap interposed between the outer periphery of the rotor 11. A rotating field in a fixed direction is generated by the action of the rotor 11, which drives the rotor 11. The rotation of the rotor 11 is caused by the pinion 11-
1. The signal is transmitted to the output shaft 15 via the intermediate shaft gear 13, a multi-stage intermediate gear group (not shown), and the output shaft gear 16, and drives an external load device. Figures 2a, b, and c show detailed views of the stator core 1 and S ball plate 6 of the small electric motor in Figure 1;
Figure a is a cross-sectional view of the stator core 1. A deep cylinder with an inner diameter _D1 closed at one end is formed by drawing from a thin plate made of magnetic material, and a plurality of strip-shaped magnetic poles 3 are inserted from the closed bottom of the cylinder around its outer periphery. The inner diameter d ₁ of the concentric circle in which the magnetic poles 3 are arranged is made larger by the gap length than the outer diameter d ₀ of the rotor 11. The length l ₁ of the magnetic pole 3 in such a configuration is constrained by d ₁ determined from the inner diameter D ₁ of the stator core 1 and the outer diameter d ₀ of the rotor 11, and is given by (D ₁ - _{d 1} ) 1/2. I can't make it longer. Also, as shown in FIGS. 2b and 2c, when forming the magnetic pole 7 on the S ball plate 6 by cutting and raising it from the center of the S ball plate 6 toward the outer circumference as shown by the arrow, the length of the magnetic pole 7 is The length l ₂ cannot be longer than d ₁ /2. Note that D ₂ indicates the outer diameter of the S ball plate. As explained in FIG. 2, in the small electric motor based on the conventional technology shown in FIG. There was a defect that was difficult to design. The present invention eliminates the deficiencies of the prior art as described above,
The purpose of this invention is to reduce restrictions on determining the dimensions of the stator and rotor, and to provide a small, high-output electric motor. In the first step of the method of the present invention, a thin plate of magnetic material is shaped into a deep dish with a diameter D ₃ larger than the final finished dimension D 0 (lower in height than the bottom diameter) as shown in Figure _3a . Therefore, it is drawn into a shape that is more like a deep dish than a cylinder. This diameter D ₃
must be selected to be larger than the sum of twice the inner diameter d ₁ of the concentric circle on which the plurality of magnetic poles cut and raised from the deep plate 101' are arranged and twice the length l ₃ of the magnetic poles. Further, the final finished dimension D ₀ is smaller than the sum of the inner diameter d ₁ of the concentric circle in which the magnetic pole is arranged and twice the length l ₃ of the magnetic pole. Next, in the second step, as shown in FIGS. 3b and 3c, a plurality of strip-shaped magnetic poles 103 are placed inside the deep dish 101' radially from the center of the bottom surface of the deep dish 101' from the outer circumferential side inward. It is cut and raised on the circumferential side and placed perpendicular to the bottom surface. 102 is a hole left after cutting and raising the magnetic pole 103, and l ₃ is the length of the magnetic pole 103. The inner diameter d ₁ of the concentric circle in which the magnetic poles 103 are arranged is set to the sum of the rotor diameter d ₀ and the air gap length. In the third step, as shown in FIG. 3 d to f, the deep dish 10
1' diameter D ₃ is reduced to a diameter D' ₀ close to the final finished dimension. In this way, a portion of the bottom surface of the deep dish 101' is moved toward the edge of the dish. That is, the magnetic pole 103 is not deformed, but the outer edge 102' of the hole 102 in which the magnetic pole is cut and raised moves from the bottom surface to the outer periphery of the cylinder having a diameter D' ₀ . In the fourth step, in the finishing step, the open end face, outer diameter mounting ear portion, etc. are shaped to give the final finished dimensions D ₀ , magnetic pole inner diameter d ₁ , and magnetic pole length l ₃
The final dimensions of FIG. 3f is a plan view of the finished stator core seen from the closed bottom side. The length l ₃ of the magnetic pole of the stator iron core manufactured based on the present invention is manufactured by cutting and raising the magnetic pole of the stator core when it is in the shape of a deep dish with a diameter D ₃ larger than the final finished dimension D ₀ , which is different from the conventional method shown in Fig. 2a. It is not limited by the outer diameter of the stator core and the rotor, unlike manufacturing methods using technology, and can be set to much longer dimensions. The thickness of the magnetic poles decreases slightly due to the scratching process, which increases magnetic resistance, but in this type of small electric motor, the area of the magnetic poles facing the rotor has a large relationship with the torque, and the thickness of the magnetic poles The effect of increasing area is far greater than decreasing it. For example, the results of a study on improving the features of a small synchronous motor (model name: D12) with a shaded coil by lengthening the magnetic poles show that an increase in output was achieved by lengthening the magnetic poles, as shown below. (Example of performance data of improvement results)

【table】

[Table] Ruku
91 〃 113 〃 (Rotor B) 1.24 times Figure 4 shows a small electric motor constructed using the stator core and S ball plate explained in Figure 3, and the numbers of each part are the same as those of the corresponding parts in Figure 1. Indicate by adding 100 to the sign. Comparing Fig. 1a and Fig. 4a, the stator in Fig. 4a has the same diameter, but the length is longer along with the rotor, and therefore a larger output can be obtained. That is clear. Furthermore, the magnetic pole 107 of the S ball plate 106 shown in FIG.
The part of magnetic pole 1 is not cut and raised using the conventional method
Form a separate piece with the same length as 03,
This may be attached and formed by a method such as welding to the S ball plate 106.

[Brief explanation of drawings]

Fig. 1a is a longitudinal sectional front view of a conventional small electric motor, Fig. 1b is a side view thereof, Fig. 2a is a longitudinal sectional front view of its stator core, Fig. 2b is a side view of an S ball plate,
Fig. 2c is a front view thereof, Figs. 3a to 3f are explanatory diagrams showing step by step the manufacturing process of the stator core that also serves as the outer cover of the electric motor in the present invention, and Fig. 4a is an application of the present invention. FIG. 4b is a side view and FIG. 4c is a front view of the small electric motor. 101... Stator core, 102... Hole, 103...
Magnetic pole, 104... Winding frame, 105... Stator winding, 10
6... S ball plate, 107... Magnetic pole, 108... Stator shaft, 109... Rear base plate, 110... Front base plate, 11
DESCRIPTION OF SYMBOLS 1... Stator, 111-1... Pinion, 112... Intermediate shaft, 113... Intermediate shaft gear, 114... Output shaft bearing, 115... Output shaft, 116... Output shaft gear, 11
7...Column, 101'...Deep dish, 102'...Outer edge.

Claims (1)

[Claims] 1. A method for manufacturing a cylindrical stator core that is paired with a plate stator core to form a stator core for a small electric motor, in which a thin plate of magnetic material is molded into a cylindrical body with one end closed. In a device in which a plurality of magnetic poles are cut and raised and arranged concentrically with the cylindrical body, the tip of which is closer to the outer periphery of the cylindrical body than the closed bottom surface, the diameter of the cylindrical body formed by the ridges. is larger than the sum of the inner diameter of the concentric circle of the magnetic pole and twice the length of the magnetic pole, and after cutting and forming a plurality of magnetic poles, the outer diameter of the bottom surface of the cylindrical body is made to be larger than the inner diameter of the concentric circle of the magnetic pole. A method for manufacturing a stator core for a small electric motor, which comprises further processing the embossment so that it is smaller than the sum of twice the length of the magnetic poles.