JPH0828950B2 - Permanent magnet rotating electric machine - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a permanent magnet rotating electric machine.

[Technical Background of the Invention and Problems Thereof] A conventional rotating electric machine having a slot in a rotor or a stator causes pulsation due to rotation during operation. In particular, this rotation pulsation becomes remarkable at low rotation speeds, and when such a rotary electric machine is used for precision machines such as machine tools and robots, these operations are adversely affected. In order to prevent rotational pulsation, for example, if a slotless structure where no slots are formed in the stator core is adopted, the gap between the stator core and the rotor becomes wider because the stator core does not have comb-shaped teeth. However, the leakage magnetic flux becomes large and the output is lowered, so that it is not possible to obtain a rotating machine having a large output. Therefore, in order to solve these problems, for example, as shown in JP-A-54-156106 and JP-A-54-54859, a double-cylindrical rotor is used to improve the output. A method of preventing the decrease of the temperature is considered. However, in such a configuration, since the rotor core is supported only on one side, it is subjected to centrifugal force due to rotation, and particularly the outer rotor core exerts a large centrifugal force and is fixed to the outer rotor core. The gap with the armature winding on the child side becomes non-uniform in the axial direction, which may cause rotational pulsation or, in some cases, damage to the rotor core. Further, in such a configuration, since the rotating shaft projects in the axial direction from the end portion of the stator, the length in the axial direction becomes long when coupled with the counterpart device, so that the space in the axial direction is limited. Problem that it is difficult to install in a narrow space,
In particular, when it is used in a precision machine, there are problems that it takes time to perform centering work at the time of coupling with a counterpart device, and it is difficult to secure assembly accuracy.

[Object of the Invention] In order to solve the above problems, the present invention provides a permanent magnet rotating electric machine that does not generate rotational pulsation during operation, can obtain a large output, and is excellent in assembly accuracy. The purpose is to

[Summary of the Invention] In order to achieve the above object, the present invention provides a stator in which armature windings are respectively wound around the inner and outer peripheral surfaces of a cylindrical stator rim, and the inner and outer peripheral sides of the stator. In the permanent magnet rotating electric machine comprising a double cylindrical rotor having an inner rotor core having a permanent magnet fixed to a surface facing the armature winding, and an outer rotor core, the inner rotor core Has a hollow hole into which a rotating shaft of a counterpart device can be inserted, and at least one end of the outer rotor core and at least one end of the inner rotor core are supported by a stator rim through bearings. (EN) Provided is a permanent magnet rotating electric machine capable of suppressing rotational pulsation at the time, improving assembly accuracy, and increasing output.

[Embodiment of the Invention] An embodiment of the permanent magnet rotating electric machine according to the present invention will be described with reference to Figs. 1 to 3. Reference numeral 1 denotes a stator having a cylindrical rim 2, and windings 3a and 3b are fixed to both inner peripheral sides of the rim 2 with epoxy resin, glass tape or the like. On the other hand, the rotor 4 has a double rotor structure composed of a cylindrical outer rotor core 5a and an inner rotor core 5b. In the rotor 4, the rim 2 has an outer rotor core 5a.
It is inserted into the stator 1 so as to be inserted between the inner rotor core 5b and the inner rotor core 5b. Further, permanent magnets 6a, 6b are fixed to the respective surfaces of the outer rotor core 5a and the inner rotor core 5b facing the winding 3. Furthermore, the outer rotor core 5a
Both ends of the inner peripheral side of the bearing 7a, 7a on the outer peripheral side of the rim 2 of the stator 1
The inner rotor core 5b is supported at one end on the inner peripheral side of the rim 2 of the stator 1 via a bearing 7c. In addition, the inner rotor core 5b is formed with a hollow hole into which the rotating shaft of the counterpart device can be inserted.

The permanent magnet 6a fixed to the outer rotor core 5a and the permanent magnet 6b of the inner rotor core 5b fixed at a position opposite to the permanent magnet 6a have different polarities. Further, the directions of the currents flowing through the windings 3a and 3b fixed to the rim 2 are the same.

 Next, the operation of this embodiment will be described.

The magnetic flux generated by the permanent magnets 5a, 5b of the rotor 4 forms a magnetic path that vertically penetrates the windings 3a, 3b fixed to the rim 2 of the stator 1, as shown by the arrow Φ in FIG. Then, the magnetic flux and the current flowing through the windings 3a and 3b generate torque in the tangential direction of the rotor 4 to rotate the rotor 4.

As described above, since the stator 1 has the slotless structure, the gap between the stator core and the rotor core can be narrowed, and the inner rotor side end portions of the outer rotor core 5a, which have a high peripheral speed during rotation, are Since it is supported on the outer peripheral side of the rim 2 of the stator 1 via bearings 7a, 7b, the gap between the outer rotor core 5a by the centrifugal force and the windings 3a, 3b fixed to the rim 2 of the stator 1 is Since it is kept constant even during high-speed rotation, the leakage magnetic flux is small and rotation pulsation does not occur from the low rotation range to the high rotation range. In this embodiment, in order to simplify the structure, only the outer rotor core 5a, which has a large peripheral speed during rotation, is supported at both ends, but the inner rotor core 5b also has a stator on the outer peripheral side. A bearing may be provided at both ends of the rim 2 of the first rim 2 to support the rim 2. Moreover, since the windings 3a and 3b are widely distributed on the circumference, the space factor is improved as compared with the conventional slot structure, and the windings 3a and 3b are further connected to the rim 2
Since it is fixed on both sides, the output can be increased. Further, since the permanent magnets 6a and 6b are fixed to the outer rotor core 5a and the inner rotor core 5b of the rotor 4, respectively, the magnetic flux becomes large. Therefore, it is possible to increase the output. Further, since the permanent magnets 6a and 6b are opposed to each other and the magnetic flux penetrates the windings 3a and 3b vertically, the leakage magnetic flux can be further reduced. Further, since the inner rotor core 5b is formed with a hollow hole into which the rotating shaft of the counterpart device can be inserted, for example, if this hollow hole is used, the core at the time of coupling with the rotating shaft of the counterpart device is formed. There is also an advantage that a stable output can be obtained because the coupling can be performed easily with high precision and the stable gap length can be maintained.

In the above embodiment, the windings 3a and 3b are fixed to the stator 1 with epoxy resin, glass tape or the like, but the winding is formed by winding the coil-printed printed wiring into a cylindrical shape to form the winding. It may be fixed at 1. As described above, by using the printed wiring, it is possible to improve productivity.

[Effects of the Invention] According to the present invention, a slotless structure in which windings are widely distributed is used, and both ends of the outer rotor core, which has a high peripheral speed during rotation, are supported by bearings, and the inner peripheral side of the stator. In addition, since a rotor with a permanent magnet fixed is provided on the outer peripheral side, smooth rotation can be obtained from the low rotation range to the high rotation range without causing rotational pulsation, and the inner rotor core can rotate the other equipment. Since a hollow hole into which the shaft can be inserted is formed, if you use this hollow hole to connect to the rotating shaft of the other device, centering is easy and highly accurate connection is possible. Therefore, it is possible to provide a permanent magnet rotating electric machine that can maintain a stable gap length and can stabilize and obtain a large output.

[Brief description of drawings]

1 is a longitudinal sectional view showing a permanent magnet rotating electric machine according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1,
FIG. 3 is a perspective view showing the winding of FIG. 1 ... Stator, 2 ... Rim, 3a, 3b ... Winding, 4 ... Rotor, 5a ... Outer rotor core, 5b ... Inner rotor core,
6a, 6b …… Permanent magnets, 7a, 7b, 7c …… Bearings.

Claims (1)

[Claims] 1. A stator in which armature windings are respectively wound around the inner and outer peripheral surfaces of a cylindrical stator rim, and a permanent surface is formed on the inner and outer peripheral sides of the stator and faces the armature windings. In a permanent magnet rotating electric machine comprising a double cylindrical rotor having an inner rotor core with a magnet fixed and an outer rotor core, the inner rotor core is capable of inserting a rotating shaft of a counterpart device. A permanent magnet rotating electric machine having a hollow hole, wherein both ends of the outer rotor core and at least one end of the inner rotor core are supported by a stator rim via bearings.