JPH0315414B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a permanent magnet type rotating electric machine that is subjected to a large load at the time of starting.

[Prior Art and Problems to be Solved by the Invention] Generally, in this type of rotating electric machine, there is an attempt to secure necessary magnetic flux using a magnetic field generated by a permanent magnet attached to a yoke. However, the field flux is always constant regardless of changes in the load current of the armature. As a result, the permanent magnet is
A phenomenon occurs in which the number of magnetic fluxes decreases due to a reaction due to the magnetic field on the armature side caused by a change in the load current of the armature, resulting in a decrease in characteristics.
This is particularly a problem in applications where starting torque is important, such as a starter motor.

Therefore, with a permanent magnet as the main pole, an auxiliary magnetic pole made of a ferromagnetic material such as iron is installed in parallel with the permanent magnet in the rotational direction of the armature, and the magnetic field generated on the armature side is controlled by using the auxiliary magnetic pole. Some are designed to increase the number of line magnetic fluxes in the field poles. However, in the past, these permanent magnets and auxiliary magnetic poles were attached to the inner circumferential surface of the yoke using adhesive or other fixing means, which resulted in poor positioning accuracy and required a large number of components to maintain accuracy. There are some drawbacks such as storage. Therefore, as shown in Utility Model Publication No. 54-84020,
In addition to forming a yoke by laminating multiple thin plates,
Some thin plate materials have mounting holes for permanent magnets to which these components can be attached, but this still requires a separate dedicated auxiliary magnetic pole, which increases the number of parts. Not only, but
This poses a problem because the magnetic flux of the permanent magnet leaks through the auxiliary magnetic pole.

[Means for Solving the Problems] In view of the above-mentioned circumstances, the present invention was devised for the purpose of providing a permanent magnet rotating electric machine that can eliminate these drawbacks. , consisting of a ring-shaped plate made of a ferromagnetic material and having an inner diameter smaller than the inner diameter of the permanent magnet and an outer diameter larger than the outer diameter of the permanent magnet, and further for inserting and mounting the permanent magnet into the ring-shaped plate. The mounting hole is formed by laminating a plurality of plate materials in which a plurality of mounting holes are opened in the circumferential direction using the plate material portion as a partition, and the width of the mounting hole in the yoke circumferential direction is wider than the circumferential width of the permanent magnet. A permanent magnet is mounted so as to be biased against one end of the mounting hole in the circumferential direction, and the hollow part formed at the other end of the mounting hole in the circumferential direction becomes a neutral zone, and the adjacent mounting holes are connected to each other. The present invention is characterized in that the plate portion for partitioning is sandwiched in the circumferential direction between a permanent magnet and a neutral band to serve as an auxiliary magnetic pole.

According to the present invention, although the yoke is formed by laminating thin plates having permanent magnet mounting holes,
This eliminates the need for a dedicated auxiliary magnetic pole and prevents magnetic flux leakage from the permanent magnet.

[Example] Next, an example of the present invention will be described based on the drawings. In the drawings, reference numeral 1 denotes a yoke of a starter electric motor, and the yoke 1 is formed by laminating a required number of ring-shaped plates 2 formed by punching thin steel plates into a predetermined shape. is set so that the outer diameter is larger than the outer diameter of the permanent magnet 3 and the inner diameter is smaller than the inner diameter of the permanent magnet 3, and the plate material 2 has a mounting plate for mounting the permanent magnet 3. A plurality of holes 2a are formed in the circumferential direction by the number of poles using the plate member 2b as a partition. The size of the mounting hole 2a is approximately equal to the thickness of the permanent magnet 3 in the radial direction, for example, the size of the permanent magnet 3.
Although the permanent magnet 3 is inserted and attached in a press-fit manner on both its inner and outer surfaces, it is wider in the circumferential direction than the circumferential width of the permanent magnet 3. The permanent magnet 3 is inserted and installed in a biased state so that it comes into contact with one end of the mounting hole 2a in the circumferential direction, but as a result, the other end of the mounting hole 2a in the circumferential direction is A hollow neutral band S is formed, and the plate portion 2b that partitions the adjacent mounting holes 2a is sandwiched between the neutral band S and the permanent magnet 3 to form an auxiliary magnetic pole. It's becoming like that.

In the figure, 4 is an armature, 5 is a commutator, and 6 is a brush.

In the embodiment of the present invention configured as described above, the yoke 1 is formed by laminating an appropriate number of plate materials 2 that have been previously produced using a molding machine such as a press. A mounting hole 2a is provided, into which the permanent magnet 3 is inserted and mounted. As a result, the permanent magnet 3 has an accurate mounting position, and is buried in the mounting hole 2a so that it does not directly face the armature 4.
Falling off from the yoke 1 or being damaged can be reliably prevented.

Furthermore, the mounting hole 2a is wide in the circumferential direction, and by mounting the permanent magnet 3 therein in contact with one end in the circumferential direction, a hollow neutral zone S is formed on the other side in the circumferential direction. Therefore, there is no need to take care to ensure the neutral zone S, and it is possible to effectively prevent the magnetic flux of the permanent magnet 3 from leaking through the plate material 2, eliminating deterioration of characteristics. This will greatly contribute to higher output. Furthermore, it is convenient that the neutral band S can be used as a through hole for a set bolt if necessary.

Moreover, the plate material 2 is made of a steel plate which is a ferromagnetic material, and the plate portion 2b for partitioning the adjacent mounting holes 2a is sandwiched between the neutral band S and the permanent magnet 3 in the circumferential direction. Therefore, since it functions as an auxiliary magnetic pole as it is, there is no need to assemble a dedicated auxiliary magnetic pole member as in the past, which not only reduces the number of parts but also simplifies the assembly process. This results in a significant improvement in workability.

Furthermore, since the auxiliary magnetic pole formed by the plate material 2 has a structure in which ferromagnetic plate materials are laminated, iron loss in the auxiliary magnetic pole can be reliably reduced, greatly contributing to improved performance.

Here, when the permanent magnet 3 is inserted into the mounting hole 2a and there is a risk that the permanent magnet 3 may shift in the circumferential direction, it is necessary to take some measure to prevent the shift. For example, the third
As shown in the figure, positioning can be achieved by bulging the inner circumferential edge 2c of the mounting hole 2a in the outer radial direction by squeezing or plucking. In this case, the permanent magnet does not need to be press-fitted. You can also eliminate it. Further, at this time, in terms of the relationship between the thickness t of the plate material 2 and the width Δx of the inner peripheral edge of the mounting hole 2a, it is preferable for processing that the thickness t is larger (t>Δx).

[Operations and Effects] In summary, the present invention is constructed as described above, and the yoke is formed by laminating ring-shaped plate materials, and the permanent magnet is inserted and attached to the mounting hole made in the plate material. Although it is designed to be assembled, all you have to do is insert the permanent magnet into the wide mounting hole so that it contacts one end in the circumferential direction, and a hollow neutral band can be placed on the other circumferential side of the mounting hole. Therefore, when installing the permanent magnet, there is no need to take care to ensure a neutral zone, and it also prevents the magnetic flux of the permanent magnet from leaking through the plate material and causing a decrease in output. Can be effectively prevented.

Moreover, the plate material is made of a steel plate which is a ferromagnetic material, and the plate part formed on the plate material to partition adjacent mounting holes is sandwiched in the circumferential direction between the neutral band and the permanent magnet. Therefore, it functions as an auxiliary magnetic pole as it is, and there is no need to individually assemble the auxiliary magnetic pole member, which contributes to high output, with a dedicated ferromagnetic material as in the past.

Furthermore, since the auxiliary magnetic pole is constructed as a laminated layer of ferromagnetic materials, iron loss in the auxiliary magnetic pole can be reliably reduced, and the plate material used to construct the yoke can be effectively used as is as a laminated auxiliary magnetic pole. This not only reduces the number of parts but also simplifies the assembly process, significantly improving workability and greatly contributing to increased performance.

[Brief explanation of the drawing]

The drawings show an embodiment of the permanent magnet type rotating electric machine according to the present invention, in which FIG. 1 is a partially cutaway side view of the electric motor, FIG. 2 is a longitudinal sectional view of the main part of the yoke, FIGS. 3A and 3B are sectional views of main parts of a yoke portion showing another example. In the figure, 1 is a yoke, 2 is a plate, 2a is a mounting hole, 2b is a plate part, 3 is a permanent magnet, and S is a neutral band.

Claims (1)

[Claims] 1. The yoke 1 is made of a ring-shaped plate made of a ferromagnetic material and has an inner diameter smaller than the inner diameter of the permanent magnet 3 and an outer diameter larger than the outer diameter of the permanent magnet 3, and the ring-shaped plate further includes: The mounting holes 2a for inserting and mounting the permanent magnets 3 are formed by stacking a plurality of plates 2, each of which has a plurality of holes in the circumferential direction using the plate portion 2b as a partition, and further includes the mounting holes 2a.
The width in the circumferential direction of the yoke is made wider than the circumferential width of the permanent magnet 3, and the permanent magnet 3 is biased and attached to the mounting hole 2a so as to contact one end in the circumferential direction, and the circumferential direction of the mounting hole 2a is The hollow part formed on the other end side becomes the neutral band S, and the plate part 2b for partitioning the adjacent mounting holes 2a is sandwiched between the permanent magnet 3 and the neutral band S in the circumferential direction. A permanent magnet rotating electrical machine characterized by being configured to serve as an auxiliary magnetic pole.