JPS6364144B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotor for a rotating machine such as a generator or an electric motor.

2. Description of the Related Art Generally, a direct drive motor for a record player is known as a rotating machine that uses a ring-shaped permanent magnet as a rotor. As shown in FIGS. 1 and 2, this motor has a ring-shaped rotor magnet 8 attached to the inner periphery of a shield case 7 that is screwed to the back of a rotating plate 1 through screw holes 9.
The rotor is constructed by gluing the On the other hand, the stator is constructed by rotatably supporting the motor shaft 2 with a bearing 3 provided in the case 4, and by winding a coil 6 around a stator core 5 provided integrally with the case 4. The rotor magnet 8 and the stator core 5 are opposed to each other by connecting the motor shaft 2, which constitutes the stator, to the rotary plate 1, which constitutes the rotor, through the through hole 10 of the shield case 7, which constitutes the rotor. , the motor is constructed. In a motor with such a configuration, the rotor magnet 8 is magnetized in the order of N, S, N, S as shown in FIG. A rotational force is generated by repeating magnetic attraction and repulsion between the motors, and is transmitted to the rotating plate 1 through the shield case 7, whereby the rotating plate 1 is rotated around the motor shaft 2. It is. And shield case 7
As shown in Fig. 3, the magnetic path of the rotor magnet 8 is formed from the N pole to the S pole on the inner peripheral surface as shown by the arrow, and from the S pole to the N pole on the outer peripheral surface. It acts to assist.

However, in a motor with such a configuration, since the shield case 7 is integrated with a magnetic material, the inner peripheral surface of the rotor magnet 8 and the bottom of the shield case 7 are separated from each other as shown in FIG. However, it is necessary to prevent the magnetic lines of force from being absorbed by the shield case 7, and therefore the shield case 7 needs to be cut and raised 11, which is disadvantageous both economically and in terms of space. Furthermore, when a resin magnet is used for the rotor magnet 8,
There is a large difference in coefficient of thermal expansion with the shield case 7 made of metal, and in cold weather the outer diameter of the lotus magnet 8 becomes extremely smaller than the inner diameter of the shield case 7, which may cause the adhesive to peel off or the rotational force generated on the rotor magnet 8. There was a drawback that the rotational speed was not transmitted smoothly to the rotary plate 1.

In order to solve this problem, the rotor of the rotating machine of the present invention is provided with a cylinder made of a magnetic material in close contact with the outer periphery of a ring-shaped magnet made of a resin magnet, and a plate made of a non-magnetic material inserted into the bottom of the ring-shaped magnet. A rotating plate having a motor shaft at the center is attached to this plate, and in order to arrange the motor shaft, a through hole of the same size as the inner diameter of the ring-shaped magnet is formed in the non-magnetic plate. The bottom of the ring resin magnet and the plate are connected through an undercut hole provided in the plate.

With this configuration, when a magnetic field is generated on the inner circumference of the ring-shaped magnet, the magnetic material on the outer circumference provides a shielding effect, and the non-magnetic plate on the bottom prevents magnetic flux leakage. can be prevented and the magnetic field can be increased.

Further, by filling the undercut hole with resin by insert molding, the resin magnet and the non-magnetic plate are firmly connected. Furthermore, by making the inner diameter of the resin magnet equal to the size of the through hole provided in the non-magnetic plate, it is possible to obtain a stator core that faces the rotor and has an outer diameter very close to the rotor inner diameter. .

The rotor of a rotating machine according to an embodiment of the present invention will be described below. FIG. has a hole 2 with a diameter equivalent to the inner diameter of the ring-shaped magnet 17.
1 is provided, and a mounting hole 20 is provided outside the ring diameter. In this way, there is no risk that the screw heads of the rotor magnet will come into contact with the stator core, further increasing space efficiency, and when manufacturing the ring-shaped magnet 12 by resin magnet molding, the rotor magnet will be located at the inner diameter part of the ring-shaped magnet 12. Insert molding of the plate 19 can be easily performed by passing the hole 21 of the plate 19 through a core (not shown) of a molding die.

FIG. 5 is an example of the embodiment shown in FIG. 4 obtained by insert molding, in which a ring-shaped resin magnet 22 is insert-molded with a non-magnetic plate 24, and has a diameter larger than the diameter of the inlet provided in the plate 24. By filling a so-called undercut hole 26 with a resin magnet 22 at the tip thereof, the two are mechanically joined. After insert molding, the magnetic tube 23 is bonded to the outer periphery of the ring-shaped resin magnet 22. Note that hole 25
is a mounting hole. In this way, the rotor magnet has the advantages of the example shown in FIG. 1 as well.

FIG. 6 shows yet another embodiment, in which a non-magnetic plate 3 is used during molding of a ring-shaped resin magnet 31.
2 is insert-molded, the undercut hole 33 provided in the plate 32 is filled with a resin magnet, and mechanically joined. It is molded around the outer periphery of the magnet 31.
The magnetic powder-containing resin body 34 is brought into close contact with the ring 31 due to contraction that occurs during the cooling process after filling the cavity.
In this way, in addition to the advantages mentioned above, the rotor magnet can be completed without any bonding process, making it extremely economical.

As is clear from the above description, in the present invention, a magnetic material is provided in close contact with the outer periphery of the ring-shaped magnet, and a non-magnetic material is provided in close contact with the bottom portion of the ring-shaped magnet.
The plate that attaches the rotating plate has a through hole the same size as the inner diameter of the ring-shaped magnet, making it possible to assemble a stator core with an outer diameter extremely close to the rotor inner diameter, resulting in high magnetic efficiency and improved performance of the rotating machine. In addition, when a ring-shaped magnet is manufactured by resin magnet molding, insert molding of the plate can be easily performed by passing a hole in the plate through the core of the molding die located at the inner diameter of the ring-shaped magnet. have

In addition, by joining the bottom of the ring resin magnet and the plate through an undercut hole provided in the plate, the ring resin magnet and plate are mechanically joined, so the rotational force generated in the ring resin magnet increases the adhesive strength. This has the effect that the signal is reliably transmitted to the plate and rotating plate regardless of the

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional motor using a permanent magnet rotor, Fig. 2 is a partial sectional view of Fig. 1,
FIG. 3 is a partial plan view of FIG. 1, FIG. 4 is a sectional view showing one embodiment of the present invention, and FIGS. 5 and 6 are sectional views showing other embodiments of the invention. 1... Rotating plate, 2... Motor shaft, 17, 22,
31...Ring magnet, 18, 23, 34
... Cylindrical magnetic material, 19, 24, 32 ... Non-magnetic material plate, 20, 25 ... Mounting hole.

Claims (1)

[Claims] 1. A cylinder of magnetic material is provided in close contact with the outer periphery of a ring-shaped magnet made of a resin magnet, a plate of non-magnetic material is provided in close contact with the bottom of the ring-shaped magnet by insert molding, and a motor shaft is attached to this plate in close contact with the outer periphery of the ring-shaped magnet. In order to attach a rotary plate prepared for this purpose and to arrange the motor shaft, a through hole of the same size as the inner diameter of the ring-shaped magnet is provided in the non-magnetic plate, and a bottom of the ring resin magnet and the plate are provided in the plate. A rotor for a rotating machine, characterized in that the rotor is joined by an undercut hole.