JPS6328241A - Magnetic wedge for rotating electric machines - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a magnetic wedge for rotating electric machines, and in particular, a magnetic wedge with excellent mechanical strength and magnetic anisotropy suitable for rotating electric machines with open slots. Regarding wedges.

[Conventional technology]

In rotating electric machines such as induction motors with a small air gap between the stator and rotor and an open slot structure, iron loss occurs due to pulsation in the air gap magnetic flux distribution due to the presence of the slots and concentration of magnetic flux on the core teeth, resulting in excitation. Causes an increase in current. Therefore, in order to suppress these problems, a material with appropriate magnetism may be used for the wedge whose main purpose is to fix the winding arranged in the core slot. Such a wedge is generally called a magnetic wedge, and for the purpose of making the magnetic flux distribution uniform in the gap and the core teeth, the magnetic flux passing from the core teeth through the wedge in the gap direction is It is well known that the magnetic resistance is desirably as small as possible, and on the other hand, the magnetic resistance against so-called leakage magnetic flux flowing from the core teeth on both sides of the slot to the core teeth via the wedge is desirably as high as possible. In other words, the characteristic of a magnetic wedge is that it allows magnetic flux to pass through only in a specific direction.
A material having magnetic anisotropy is desirable.

As a magnetic wedge having magnetic anisotropy, for example, published magazine (Asuyo Denki, Vol. 34, 1970 J,) 146
-150) are known.

Among these various magnetic wedges, there is one having the configuration shown in FIG. 3 that can relatively effectively exhibit its characteristics as a magnetic wedge. That is, a plurality of L-shaped magnetic machine pieces 1 are stacked in the longitudinal direction of the wedge, and little consideration is given to the magnetic path within the L-shaped member wedge. Furthermore, since the wedges are laminated in the longitudinal direction, there is also a problem in terms of mechanical strength.

[Problem that the invention seeks to solve]

As mentioned above, it is desirable for magnetic wedges for rotary machines to have magnetic anisotropy, and from a practical point of view,
This is the original purpose of the wedge. It needs to have sufficient mechanical strength to function as a device for fixing the winding in the slot, and it needs to be easy to manufacture and inexpensive.

However, conventional magnetic wedges are not necessarily sufficient in terms of magnetic properties, mechanical strength, and ease of manufacture, and there is room for improvement.

That is, in the magnetic wedge described above, as shown in FIG. 4, the magnetic flux from the side surface of the iron core tooth 3 through the magnetic piece 1 and the air gap 4 to the secondary conductor 5 has a magnetic resistance relationship as shown by the broken line. It flows through the shortest distance from the magnetic piece 1, concentrates on the core teeth of the magnetic piece 1, and is not sufficiently guided to the center of the wedge. Therefore, since the magnetic flux density in the air gap is still distributed so as to be low at the location where the non-magnetic machine 2 is located, the maximum magnetic flux density B max cannot be maintained, and the effective magnetic flux density B decreases.

In addition, in order to provide magnetic anisotropy in this wedge, magnetic insulation is performed using a non-magnetic material in the center of the wedge, but since the magnetic pieces that make up the wedge themselves are magnetically isotropic, leakage may occur. It is also insufficient as a countermeasure against magnetic flux.

Furthermore, because this wedge has magnetic pieces laminated in the longitudinal direction of the wedge, it also has strength against shearing force in the thickness direction of the stem, which is important for securing the winding wire in the slot, which is the original responsibility of the wedge. There are problems, and it is difficult to ensure sufficient mechanical strength as a winding fixing device.

An object of the present invention is to provide a magnetic wedge that has desirable magnetic anisotropy and also has the necessary mechanical strength.

[Means for solving problems]

In the present invention, an L-shaped member is constructed by laminating a plurality of rectangular magnetic thin plates bent along the longitudinal direction, and two L-shaped members are arranged back to back and bonded or pressure welded. By taking the necessary steps to integrate them, a magnetic wedge with excellent mechanical strength and magnetic anisotropy can be obtained, and the various problems described above can be solved.

[Effect]

In the magnetic wedge according to the present invention, thin plates made of magnetic material are laminated along the longitudinal direction of the wedge, so the effective magnetic flux flowing from the iron core tooth part, which is in contact with one end in the width direction of the stem, to the air gap side is
#! The magnetic resistance in this direction is small because it passes through the thin plates that make up the . On the other hand, with respect to leakage magnetic flux from the core through the width direction of the wedge to the adjacent core teeth, the magnetic resistance is large because the thin plates are arranged so that they do not come into direct contact with each other. That is, it has magnetic anisotropy desirable as a magnetic wedge.

In addition, since magnetic wedges are made of laminated thin plate magnetic machines,
The magnetic path is independent for each sheet. Therefore, the magnetic flux from the core tooth portion that is in contact with one end of the wedge in the width direction passes through each magnetic path, and there is little leakage to adjacent thin plates. Therefore,
The distribution of magnetic flux at the core tooth end and the wedge end is relaxed, and the air gap magnetic flux at the location of the slot is smoothed.

Furthermore, since the magnetic wedge has thin plates laminated in the width direction and thickness direction of the wedge, sufficient mechanical strength can be ensured for the wedge's original purpose as a winding fixing device.

[Embodiment] FIG. 1 is a sectional view of a main part of a rotating electrical machine showing an embodiment of the present invention. A winding 9 with an insulating material 8 wound thereon is installed in a slot 7 formed in the stator core 6, and a magnetic wedge 11 is driven using the groove 10 formed in the core tooth 3 at the opening of the slot 7. , fixedly supports the winding 9. 12 and 13 are spacers that adjust the height dimension of the winding 9 in the slot 7, and 14 and 15 are spacers that adjust the widthwise gap between the thrower 1-7 and the winding 9. The secondary conductor 5 is rotatably supported in the inner hole of the stator core 6 with a gap 4 in between.

The details of the magnetic wedge 11 are shown in FIG. 2. A rectangular magnetic plate on which a non-magnetic material such as aluminum or steel is vapor-deposited or crimped on one or both sides of a magnetic iron plate is placed in advance in the longitudinal direction. A thin magnetic material plate 16 is made by bending the magnetic material along the following directions. A plurality of thin plates of magnetic material are laminated to form an L-shaped member 17. Two L-shaped members 17 are arranged back to back, and the thin plates of magnetic material 16 are integrated with each other by means such as adhesion or pressure welding to form a magnetic wedge. is composed of Therefore, in the magnetic wedge, since a non-magnetic layer is formed between the magnetic thin plates, each of the magnetic thin plates is almost magnetically insulated.

In the magnetic wedge 11 of the embodiment configuration, as can be seen from FIG. Because it flows, the magnetic resistance is small, and the thin magnetic material plate 1
Since the magnetic fluxes 6 are aligned in the width direction of the wedge, the effective magnetic flux incident on the secondary conductor 5 is increased because it is uniformly guided to the center in the width direction of the wedge.

On the other hand, with respect to leakage magnetic flux Φ passing through the magnetic wedge 11 in the l'' direction, regardless of whether it enters the wedge from either the left or right side of the iron core teeth, it will flow in the direction perpendicular to the alignment direction of the thin magnetic material plates 16. Since it is impossible for the magnetic flux to pass through the non-magnetic adhesive layer, the magnetic resistance in this direction becomes high and leakage magnetic flux is suppressed.

In addition, the magnetic wedge 11 has a longitudinal direction of a thin plate constituting the wedge.
Since the wedge extends in the width direction and thickness direction, it can ensure sufficient mechanical strength against shearing forces in either direction, and can also be used as a winding fixing device, which is the original role of the wedge. , without impairing its functionality.

In the above embodiment, a material in which a non-magnetic material such as aluminum or copper is vapor-deposited or crimped in advance on the magnetic thin plate constituting the magnetic wedge is used. A magnetic wedge with the same effect as the magnetic wedge obtained by using this method can be obtained. In other words, a magnetic iron plate to which a non-magnetic material is not vapor-deposited or crimped, and a non-magnetic material such as aluminum or copper having the same shape as the magnetic iron plate are arranged alternately and then integrated by adhesion or crimping. That goal is achieved. In this case, the same effects as those of the above-mentioned embodiments can be obtained, and since operations such as vapor deposition or pressure bonding when manufacturing a magnetic thin plate are not necessary, it is also possible to expect a cost reduction effect due to a reduction in the number of man-hours. Furthermore, in this case, the magnetic properties of the magnetic wedge itself can be changed by changing the thickness of the non-magnetic material, so there is an effect that a magnetic wedge having magnetic properties as required can be obtained.

In addition, since the magnetic thin plates that make up the wedge are each magnetically independent, the magnetic flux passing through each magnetic path reaches the air gap without interfering with each other, so the air gap magnetic flux located at the center of the slot The density is also smoothed, and an increase in effective magnetic flux density can be expected.

Furthermore, since the magnetic wedge is made by aligning the long sides of the thin strips of magnetic material with the longitudinal direction of the wedge and laminating them in the width direction and thickness direction of the wedge, it can withstand shearing forces in any direction. This ensures sufficient mechanical strength.

〔Effect of the invention〕

According to the present invention, magnetic resistance is large against leakage magnetic flux flowing in the width direction of the magnetic wedge, while magnetic resistance against effective magnetic flux flowing in the thickness direction of the wedge is small, meeting the requirements of the target rotating electric machine. A magnetic wedge with desirable magnetic anisotropy can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of essential parts of a rotating electric machine according to an embodiment of the present invention, Fig. 2 is a perspective view of a magnetic wedge of the present invention, Fig. 3 is a perspective view of a conventional magnetic wedge, and Fig. 4 is a perspective view of a conventional magnetic wedge. It is a figure showing the flow of magnetic flux when a magnetic wedge is used. To-hK-P upper 4χyu ↑also 1m-L 10th

Claims (1)

[Scope of Claims] 1. A rectangular magnetic thin plate is bent along the longitudinal direction, a plurality of plates are laminated to form an L-shaped member, and the two L-shaped members are placed back to back and formed to have a convex cross section, and are integrally formed. A magnetic wedge for rotating electric machines that is characterized by 2. A magnetic wedge for a rotating electrical machine according to claim 1, characterized in that a magnetic thin plate is used on the surface of a magnetic machine with a non-magnetic machine deposited or pressed. 3. In claim 1, a magnetic material for a rotating electrical machine, characterized in that it is formed by alternately arranging and laminating strip-shaped magnetic iron plates and non-magnetic machine plates having substantially the same shape as the magnetic iron plates. wedge. 4. A magnetic wedge for a rotating electric machine according to claim 3, characterized in that the thickness dimensions of the magnetic iron plate and the non-magnetic machine plate are different.