JPH03195338A - Permanent magnet type rotor - Google Patents

Abstract

PURPOSE:To eliminate uneven gap between permanent magnets and to form a uniform magnetic field by filling the gaps between a plurality of permanent magnets with permanent magnet powder, applying a nonmagnetic tubular body thereon and inserting a molded member into a communication hole thereby holding the permanent magnet and the permanent magnet powder. CONSTITUTION:A yoke 4 is fitted to a rotary shaft 8. A plurality of holes 5 are made in the direction of the rotary shaft through the yoke 4. A side yoke 11 is arranged on one side of the yoke 4. A nonmagnetic cylinder 2 is then fitted thereto. A tile type permanent magnet 3 is placed in a recess made between the yoke 4, the side yoke 11 and the nonmagnetic cylinder 2 and secured firmly in place through a die cast member 7. Consequently, the opposite end sections 9 are coupled each other through a molded member passing through the hole 5 of the yoke 4 and communication holes of the side yokes 11, 12. By such arrangement, irregularities of rotation and torque can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a permanent magnet rotor used in an electric motor.

[Prior Art] As shown in the cross-sectional view of FIG. 2, a conventional permanent magnet rotor has a required number of shingle-shaped permanent magnets 3 arranged on a yoke 4 fitted on a rotating shaft 8, and the upper surface of the rotor is was covered with a non-magnetic cylinder 2.

[Problems to be Solved by the Invention] In the conventional permanent magnet rotor described above, the gaps 14 between the tile-shaped permanent magnets 3 tend to be uneven, which causes uneven rotational moment, non-uniformity of the magnetic field, etc. Therefore, there was a problem that torque unevenness was likely to occur, and vibration and noise increased especially during high-speed rotation.The purpose of the present invention is to eliminate the unevenness of the gaps 14 and create a permanent magnet that forms a uniform magnetic field. Our objective is to provide a shaped rotor.

The present invention relates to the configuration of the gap 14 in the permanent magnet rotor shown in FIG. 2 above.

[Means for Solving the Problems] In order to solve the above problems, the present invention fills the gaps between a plurality of permanent magnets arranged on the outer periphery of a permanent magnet rotor with permanent magnet powder. .

Furthermore, the permanent magnet rotor and the permanent magnet powder are arranged on a yoke that fits on the rotating shaft, and the upper part of the yoke is covered with a non-magnetic cylindrical body.

Further, the yoke is provided with a hole passing through the axis along the rotation axis, and both sides of the yoke are sandwiched between two side yokes each having a communication hole that communicates with the hole. The permanent magnet and the permanent magnet powder are held by a holding member that presses the yoke.

Further, the permanent magnet powder is made of the same magnetic material as the permanent magnet.

Further, the permanent magnet powder is mixed into a resin material to fill the gap.

Furthermore, the magnetic properties of the resin material mixed with the permanent magnet powder are made to be the same as the magnetic properties of the permanent magnet.

[Function] The permanent magnet rotor of the present invention configured as described above acts to make the magnetic characteristics of the gap portion equal to the magnetic characteristics of the permanent magnet, thereby alleviating the disturbance of the magnetic field due to the gap.

[Example] In the first part, FIG. 2 is a vertical cross-sectional view and a cross-sectional view, respectively, of a permanent magnet type rotor according to the present invention.

The permanent magnet rotor of the present invention shown in FIGS. 1 and 2 is assembled by the following procedure. First, the yoke 4 is fitted onto a temporary assembly shaft corresponding to the rotating shaft 8. As shown in FIG. 2, a plurality of holes 5 are formed through the yoke 4 in the direction of the rotation axis. Next, a ring-shaped side yoke 11 is placed on one side of the yoke 4. The side yoke 11 is provided with similarly arranged holes communicating with the holes 5 of the yoke 4. Next, the non-magnetic cylinder 2 is fitted. Next, a required number of tile-shaped permanent magnets 3 are placed in the recess between the yoke 4, the side yoke 11, and the non-magnetic cylinder 2, and the magnetic properties are set in the gaps 13, 14, etc. between the tile-shaped permanent magnets and the path. After that, the side yoke 12 is fitted. The night yoke 12 is provided with similarly arranged holes communicating with the holes 5 of the yoke 4.

Finally, each member assembled as described above is firmly fixed by a die-casting member 7. The die-cast member 7 is pressure-molded using a resin material or the like, and has a shape in which the end ring portions 9 on both sides are connected to each other by a molded material that communicates the hole 5 of the yoke 4 with the communicating holes of the side yokes 11 and 12. Become. Further, by filling a larger amount of the permanent magnet powder, the die-cast member is compacted when the die-cast member is press-molded, so that each tile-shaped permanent magnet 3 can be firmly fixed.

In addition, by mixing the above-mentioned permanent magnet powder with a resin material such as polyethylene, melting it, and solidifying it, the tile-shaped permanent magnet 3 can be further firmly attached to the yoke 4, the side yokes 11 and 12, the non-magnetic cylinder 2, etc. In addition to being able to adhere to the surface, it is also possible to improve workability. By mixing the above-mentioned resin material, the density of the above-mentioned permanent magnet powder becomes thinner, and its magnetic properties become different from those of the shingled permanent magnet, but this can be compensated for by using a permanent magnet powder material with strong magnetic properties. can.

Since the above-mentioned permanent magnet powder has almost the same magnetic properties as each tile-shaped permanent magnet 3, each tile-shaped permanent magnet 3 and the above-mentioned permanent magnet powder are integrated into an isometrically continuous ring-shaped permanent magnet. Form a magnetic material. Therefore, when magnetizing the permanent magnet rotor after assembly, the magnetization pattern can be set at any position on the circumference.

On the other hand, in conventional permanent magnet rotors, the gaps between the tile-shaped permanent magnets are almost non-magnetic, so the above magnetization must be done in accordance with the position of each tile-shaped permanent magnet, which reduces the manufacturing process. This caused complications. Furthermore, due to the uneven spacing of the gaps, the magnetic field distribution after magnetization becomes uneven, resulting in uneven torque.

The above-mentioned conventional problems are caused by the unevenness of magnetic suitability between the tile-shaped permanent magnet and the above-mentioned gap, so the present invention completely solves the above problems.

[Effects of the Invention] According to the present invention, it is possible to suppress the occurrence of 1 to 1 torque unevenness due to non-uniformity of the magnetizing magnetic field distribution in a conventional permanent magnet rotor, thereby preventing uneven rotation of the electric motor, torque cogging, 7- It is possible to prevent noise, vibration, etc. due to rotational imbalance during high-speed rotation.

Furthermore, the manufacturing process associated with positioning between the tile-shaped permanent magnets can be omitted.

Furthermore, each shingled permanent magnet can be firmly fixed to the motor rotor.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a permanent magnet rotor according to the present invention, and FIG. 2 is a longitudinal sectional view of an embodiment of a permanent magnet rotor according to the present invention.
FIG. 3 is a cross-sectional view of the embodiment. 1... Permanent magnet rotor, 2... Non-magnetic cylinder, 3
... Tile-shaped permanent magnet, 4... Yoke, 5... Hole, 6
... Rotation stopper, 7 ... Die-cast member, 8 ... Rotating shaft, 9 ... End ring part, 1] ... Side yoke, 13 ... Gap, 15 ... Permanent magnet powder .

Claims (1)

[Claims] 1. In a permanent magnet rotor of an electric motor, at least a gap between a plurality of permanent magnets arranged on the outer periphery of the permanent magnet rotor is filled with permanent magnet powder. A permanent magnet rotor characterized by: 2. The permanent magnet according to claim 1, wherein the permanent magnet rotor and the permanent magnet powder are arranged on a yoke that fits on a rotating shaft, and a non-magnetic cylindrical body is provided to cover the upper part of the yoke. shaped rotor. 3. In claim 2, the yoke is provided with a hole penetrating along the rotation axis, and two side yokes are provided with communication holes that press both sides of the yoke and communicate with the hole; A permanent magnet rotor comprising: a holding member that communicates the communicating holes of the two side yokes with the holes of the yokes and presses and holds the yokes. 4. A permanent magnet type rotor according to claim 1, wherein the permanent magnet powder is made of the same magnetic material as the permanent magnet. 5. In claims 1 to 3, the permanent magnet powder is mixed into a resin material to fill at least the gaps between the plurality of permanent magnets disposed on the outer periphery of the permanent magnet type rotor. Features a permanent magnet rotor. 6. The permanent magnet rotor according to claim 5, wherein the resin material mixed with the permanent magnet powder has magnetic properties equivalent to those of the permanent magnet.