JPH0810971B2 - Method for manufacturing rotor part of rotating field motor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a rotor part of a rotary field type electric motor, which is suitable for mass production because the rotor part can be manufactured with high accuracy and defective products do not occur.

(Prior Art) The applicant of the present invention has already proposed Japanese Patent Application No. 63-219861 as a rotary field electric motor that is suitable for mass production and can obtain a large driving torque. The previously proposed rotating field type motor will be briefly described with reference to FIGS. 3 and 4. FIG. 3 is a longitudinal sectional view of the previously proposed rotating field type electric motor, and FIG. 4 is a sectional view taken along line AA of FIG.
FIG. 6 is a layout view of a power generation substrate, a drive coil, and the like as viewed from the arrow.

In FIGS. 3 and 4, a pulley 2 formed by cutting brass or aluminum into the rotary shaft 1 is fixed by fitting press-fitting or the like, and a dish-shaped magnet yoke 3 made of a magnetic material is caulked to the pulley 2. It is fixed by.
Then, an annular magnet 4 having an outer diameter that is the full inner diameter of the magnet yoke 3 is arranged and fixed to the magnet yoke 3 by adhesion or the like. The magnet 4 is divided into magnets in the circumferential direction and is provided with a drive magnetized portion. Further, the outer peripheral portion is magnetized with a large number of N poles and S poles alternately to form an FG multipole magnetized portion 4a. It is provided. The rotary shaft shaft 1, the pulley 2, the magnet yoke 3 and the magnet 4 constitute a rotor portion.

The rotary shaft 1 is rotatably held in the housing 6 by bearings 5, 5. Then, the stator yoke 7 is fixed to the housing 6 by crimping, screwing, or the like, the printed board 8 is fixed to the surface of the stator yoke 7 on the magnet 4 side, and the rotating magnetic field is applied to the printed board 8 so as to face the magnet 4. A plurality of drive coils 9, 9, 9 for generating are arranged and fixed by adhesion or the like. Further, a power generation substrate 10 provided with a rectangular wave power generation coil 10a facing the FG multipole magnetized portion 4a is arranged and fixed on these drive coils 9, 9, 9 by bonding or the like. These housing 6, stator yoke 7 and printed circuit board 8
The drive coil 9, 9, 9 and the power generation board 10 constitute a stator section. On the printed circuit board 8, connection terminals (not shown) to which the terminals of the drive coils 9, 9, 9 are connected are provided by printed wiring, and a magnetic sensor such as a Hall element for detecting the rotational position is used. Elements 11, 11, 11 are provided, and further a connector 12 and a rectangular wave generating coil
Connection terminals and the like for the terminals of 10a are provided.

In such a configuration, the drive coils 9, 9, 9 can be arranged so as to be separated from the rotating shaft 1 by the full outer diameter of the magnet yoke 3, so that the arm for generating the drive torque can be lengthened. As a result, the driving torque of the roller portion can be increased. Therefore, if the drive torque of the electric motor is the same, the number of drive coils 9, 9, 9 may be smaller than in the conventional rotary field type electric motor of this type, and the number of parts and the work process can be reduced. Therefore, it is suitable for mass production.

(Problems to be Solved by the Invention) In the rotating field type motor, since the magnet yoke 3 is fixed to the pulley 2 by caulking or the like, the rotating shaft shaft 1 press-fitted and fixed to the pulley 2 Therefore, the perpendicularity of the magnet yoke 3 cannot be obtained accurately. Therefore, the surface of the magnet 4 fixed to the magnet yoke 3 facing the drive coils 9, 9, 9 is not perpendicular to the fixed shaft 1, and it is difficult to mass-produce the rotor portion with high accuracy. Therefore, surface wobbling tends to occur with the rotation of the rotary shaft 1. And the magnet 4
The drive coils 9, 9 and 9 must be separated from each other by a distance that allows the above-mentioned surface wobbling, and the magnetic resistance increases by that amount, and the drive torque cannot be increased.

Further, since the pulley 2 is formed by cutting brass, aluminum or the like, the unit price of parts is high. Then, in order to fix the magnet 4 to the magnet yoke 3 by adhesion, work steps such as primer application, adhesive application, and ultraviolet curing are necessary. Therefore, the manufacturing cost is high and it is not suitable for mass production.

The present invention has been made in order to improve the above-mentioned problems of the rotary field type motor, and the rotor part of the rotary field type motor is suitable for mass production because the rotor part can be manufactured with high accuracy and no defective products are generated. It aims at providing the manufacturing method of.

(Means for Solving the Problem) In order to achieve such an object, a method of manufacturing a rotor portion of a rotating field type electric motor according to the present invention includes a magnet yoke fixed to a rotary shaft, and a circumferential direction of the magnet yoke. A method of manufacturing a rotor portion of a rotary field electric motor, wherein a magnet magnetized separately is fixed to a rotor, and further a pulley is fixed to the rotary shaft, wherein a thin elastic member is provided between the magnet and the magnet yoke. Interpose a member,
The magnet, the magnet yoke, and the rotary shaft are pressed against a molding die to be positioned, and the pulley is resin-molded by insert molding to integrally form the pulley, the magnet, the magnet yoke, and the rotary shaft with resin. Then, the rotor part is manufactured by fixing it to.

Then, both sides of the elastic thin member may be made to have adhesiveness, and the magnet yoke and the magnet may be bonded by this adhesiveness.

Further, the thin member having elasticity may be made to have an adhesive property by thermosetting, and the thin member may be hardened simultaneously with resin molding to bond and fix the magnet yoke and the magnet.

(Function) Since the magnet yoke and the magnet and the rotary shaft that have the thin elastic member interposed therebetween are pressed against the molding die for positioning, the thin elastic member causes variations in the thickness and flatness of the magnet and the magnet yoke. Can absorb variations in thickness. Then, the pulley, the magnet, the magnet yoke, and the rotary shaft are integrally fixed with resin by resin-molding the pulley by insert molding in such a state, so that an accurate rotor portion can be manufactured.

If the thin member having elasticity has adhesiveness on both sides, the magnet can be temporarily fixed to the magnet yoke by this thin member, and the magnet yoke and the magnet can be easily attached to the molding die to improve workability. Is good.

If the thin member having elasticity produces adhesiveness by thermosetting, the thin member can be cured at the same time as the resin molding to bond and fix the magnet to the magnet yoke.

(Example) Hereinafter, an example of the present invention will be described with reference to FIG.
FIG. 1 is a vertical cross-sectional view of an example of a rotating field type electric motor using a rotor portion manufactured by the method for manufacturing a rotor portion of a rotating field type electric motor according to the present invention. In FIG. 1, the same members as those in FIG. 3 are designated by the same reference numerals, and duplicate description will be omitted.

The example shown in FIG. 1 is different from that shown in FIGS. 3 and 4 in the following points. First,
A thin elastic member 21 such as a rubber film is interposed between the magnet 20 and the magnet yoke 3. Further, the inner peripheral surface of the annular magnet 20 is provided with an enlarged portion 20a whose inner diameter is enlarged from the magnet yoke 3 side by chamfering or the like. Further, the pulley 22 is molded of resin. Then, when the pulley 22 is resin-molded, the magnet yoke 3 and the magnet 20 in which the rotary shaft 1 and the thin member 21 having elasticity are interposed are pressed against the molding die and positioned, and the pulley 22 is insert-molded to form the pulley 22. By being resin-molded, the magnet yoke 3, the magnet 20, and the rotary shaft 1 are integrally fixed to the pulley 22 by resin molding. Here, the enlarged portion 20a of the magnet 20 is covered with resin. Therefore, the rotor portion including the rotary shaft 1, the magnet yoke 3, the magnet 20, and the pulley 22 is integrated with resin to be configured as a single item. Reference numeral 20b is an FG multi-pole magnetized portion provided on the outer peripheral portion of the magnet 20 by magnetizing a large number of N poles and S poles.

In such a rotor part manufacturing method, since the magnet 20 is positioned by the molding die and fixed with resin with reference to the rotary shaft 1 itself, the surface of the magnet 20 facing the drive coils 9, 9, 9 is the rotary shaft. It is fixed perpendicularly to the shaft 1 with high precision. Therefore, the rotation of the rotary shaft 1 prevents the magnet 20 from wobbling.
By the way, when fixing it integrally with resin, the magnet 20
The magnet yoke 3 is pressed against the molding die to be positioned, and the magnet 20 and the magnet yoke 3 are elastically pressed against the molding die by the thin member 21 having elasticity. Therefore, variations in the thickness and flatness of the magnet 20 and variations in the thickness of the magnet yoke 3 are absorbed by elastic deformation of the thin member 21 having elasticity. Therefore, even if the thickness of the magnet 20 or the magnet yoke 3 is thicker than a predetermined value, the magnet 20 will not be damaged by an excessive force.
Further, even when the thickness is smaller than a predetermined value, the magnet 20 does not play in the mold and cannot be sufficiently pressed, so that the surface of the magnet 20 is not displaced and fixed. As described above, the rotor portion is manufactured with high accuracy and easily, and there is no defective product, which is suitable for mass production.

Since the rotor portion is manufactured with high accuracy, the gap between the magnet 20 and the drive coils 9, 9, 9 facing the magnet 20 can be narrowed, and the drive torque of the rotary field electric motor can be increased accordingly.

Further, as in the conventional rotor of this type of rotary field electric motor, a work step of fixing the magnet 4 to the magnet yoke 3, a work step of press-fitting the rotary shaft 1 into the pulley 2, and a magnet yoke to the pulley 2. Work steps such as crimping 3 can be omitted. Moreover, the pulley 22 can be manufactured from resin at low cost. Therefore, the entire rotor section can be manufactured at low cost, and this is also suitable for mass production.

By forming the enlarged portion 20a on the magnet 20 and molding the enlarged portion 20a so as to cover it with a resin, the magnet 20 can be reliably prevented from falling off, and a robust rotor portion can be manufactured.

FIG. 2 is a partially enlarged vertical cross-sectional view of another example of the rotor section manufactured by the method for manufacturing the rotor section of the rotating field electric motor according to the present invention.

In FIG. 2, the magnet 20 of the magnet yoke 30 is shown.
The uneven surface 30a is provided on the side surface. A thin member 2 having elasticity is provided between the uneven portion 30a and the magnet 20.
1 intervenes. As described above, by providing the uneven portion 30a, the thin member 21 having elasticity can be easily elastically deformed, and the elasticity of pressing the magnet 20 against the molding die can be made small.

The thin member 21 having elasticity may be a so-called double-sided tape having adhesiveness on both sides. With the thin member 21 having such elasticity, the magnet 20 can be attached to the molding die in a state where the magnet 20 is temporarily adhered to the magnet yokes 3 and 30, and the work at the time of resin molding is easy.

Further, the elastic thin member 21 may be one that produces adhesiveness by thermosetting. The elastic thin member 21 is cured during resin molding, and the magnet 20 is also adhesively fixed to the magnet yokes 3, 30 by the elastic thin member 21 itself.

(Effect of the Invention) The method of manufacturing the rotor portion of the rotating field electric motor according to the present invention is
The following effects are achieved.

Since the magnet, the magnet yoke, and the rotary shaft that have a thin elastic member interposed between them are pressed against the molding die for positioning, and the pulley is resin-molded by insert molding to integrate the magnets, variations in magnet thickness and flatness can occur. Also, the variation in the thickness of the magnet yoke is absorbed by the elastic deformation of the thin member having elasticity, and the rotor portion can be accurately manufactured by the positioning by pressing it against the molding die. Further, due to the elastic deformation of the thin member having elasticity, an unreasonable force is not applied to the magnet at the time of resin molding, and a defective product due to damage of the magnet is not generated. Further, since the rotor portion is integrated with the resin molding of the pulley, the conventional assembly work steps can be omitted, which is suitable for mass production and can be manufactured at low cost.

If the magnet is temporarily fixed to the magnet yoke due to the adhesiveness of both surfaces of the thin member having elasticity, the magnet can be easily mounted on the molding die.

In addition, if the magnet is bonded and fixed to the magnet yoke by the adhesiveness of the elastic thin member by thermosetting, the magnet can be fixed more firmly than the fixing by only molding the resin.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an example of a rotary field electric motor using a rotor section manufactured by the method for manufacturing a rotor section of a rotary field electric motor of the present invention, and FIG. FIG. 3 is a partially enlarged vertical cross-sectional view of another example of a rotor section manufactured by the method for manufacturing a rotor section of a rotary field electric motor, and FIG. 3 is a vertical cross-sectional view of the previously proposed rotary field electric motor. , FIG. 4 shows the third
FIG. 4 is a layout view of a power generation substrate, a drive coil, and the like as viewed from the direction of arrow AA in the figure. 1: rotating shaft, 2,22: pulley, 3,30: magnet yoke, 4,20: magnet, 9: drive coil, 21: elastic thin member.

Claims (3)

[Claims] 1. A rotating field type motor having a magnet yoke fixed to a rotary shaft, a magnet magnetized separately in the circumferential direction fixed to the magnet yoke, and a pulley fixed to the rotary shaft. A method of manufacturing a rotor part, wherein a thin member having elasticity is interposed between the magnet and the magnet yoke, and the magnet, the magnet yoke and the rotary shaft are pressed against a molding die for positioning, and insert molding is performed. The rotor part of the rotating field type electric motor is characterized in that the pulley, the magnet, the magnet yoke, and the rotary shaft are integrally fixed with resin to form the rotor part by molding the pulley with resin. Manufacturing method. 2. The rotor portion of a rotating field type electric motor according to claim 1, wherein both sides of the elastic thin member have adhesiveness, and the magnet yoke and the magnet are adhered by the adhesiveness. Production method. 3. The thin member having elasticity is made to be tacky by thermosetting, and the thin member is hardened simultaneously with resin molding to bond and fix the magnet yoke and the magnet. 2. A method for manufacturing a rotor section of a rotating field electric motor according to 1.