JP2012165534A - Rotor for permanent magnet rotary electric machine and balance adjustment method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor for a permanent magnet rotary electric machine that allows proper balance adjustment without cutting work, and to provide a balance adjustment method therefor.SOLUTION: A rotor 4 for a permanent magnet rotary electric machine includes: a rotor core 13 that holds permanent magnets; and a balancing ring 16 that is fitted at least on an axial end of the rotor core 13 and has a plurality of projections 20 that allow balance adjustment weights 21 to be fixed thereto by caulking. Balance adjustment is made at least either by fitting the balance adjustment weights 21 on the projections 20 or by cutting the projections 20.

Description

  The present invention relates to a rotor of a permanent magnet type rotating electrical machine having a permanent magnet that rotates oppositely with a predetermined gap in a stator, and a balance adjustment method thereof.

  In this type of permanent magnet type rotor and other rotors, there is always an unbalance (unbalanced state of the rotating object) due to deviations such as material non-uniformity and processing tolerances. To do. This imbalance becomes a load, and when rotating, it becomes a centrifugal force in the circumferential direction of the rotor and affects the rotation. Therefore, the load increases in accordance with the rotational speed of the rotor, causing a radial displacement. This radial displacement causes vibrations in the rotor and the rotating machine as axial vibrations. Therefore, in the rotating machine, as shown in JIS B0905 (balance between rotating machine and rigid rotor), the rotor and rotating body The balance is adjusted so as to be less than the allowable unbalance amount calculated by taking into consideration the mass of the rotating body, the rotation speed, and the distance to the correction surface with respect to the balance quality grade determined by the size and application.

As a rotor for performing such balance adjustment, for example, a rotor core in which electromagnetic steel sheets are laminated, a permanent magnet arranged in a circumferential and convex polygonal shape on the rotor core, and a radially outer side of the permanent magnet arranged in the rotor core are provided. There has been proposed a motor and a compressor having a balanced adjustment hole (for example, see Patent Document 1).
In addition, a method for manufacturing an electric motor has been proposed in which the maximum rotational speed of the electric motor is adjusted by changing the thickness, size, and number of end plates made of a magnetic material disposed at the end of the rotor (for example, Patent Document 2).

Furthermore, the electric motor is composed of a rotor having a magnet embedded in a rotor iron core and a stator, and the balance adjusting weight integrated end plate and the balance adjusting weight integrated end plate are combined with the balance adjusting weight integrated end plate. There has also been proposed an electric motor in which a notch portion is provided in an end plate portion of an adjustment weight-integrated end plate (for example, see Patent Document 3).
Furthermore, one end plate sandwiching the laminated iron core in which the magnet is embedded has an integral structure of a resin end ring and a metal end ring, and the resin end ring and the metal end ring Has also proposed a rotor of an electric motor having a stepped shape in which the portions are in contact with each other (see, for example, Patent Document 4).

JP 2008-178233 A Republished patent WO02 / 019499 JP 2004-336925 A JP 2004-222348 A

  However, in the conventional example described in Patent Document 1, since it is necessary to provide a balance adjustment hole directly in the rotor core, when the distance between the permanent magnet and the outer diameter of the rotor core is narrow, a balance adjustment hole is provided at a necessary position. Is difficult. In addition, it is necessary to use a tool such as a drill, and drilling powder or the like may enter between the magnet insertion hole of the rotor or the laminated rotor core, causing a problem in quality. Furthermore, even if the balance adjustment hole is provided in the region where the magnetic flux is small, the adjustment hole, that is, the space, causes a deviation in the flow of the magnetic flux in the axial direction and the radial direction. There are challenges.

  Further, in the conventional example described in Patent Document 2, the maximum rotation speed of the electric motor is adjusted by changing the thickness of the balance adjustment weight. However, the balance adjustment weight, the rotor core, and the shaft of the permanent magnet are used. The direction restraining end plate is integrated by caulking pins. For this reason, it is necessary to determine the balance adjustment, that is, the size of the balance adjustment weight and the number of balance adjustment weights before the integration process using caulking pins. However, it is difficult to make it less than the specified unbalance amount. In addition, a caulking pin hole for passing the caulking pin is required in the rotor core, and even if the caulking pin hole is provided at a position where there is little influence on the flow of the magnetic flux compared with the case where there is no caulking pin hole, it can be considered that the effect of efficiency reduction is considered. There are unsolved issues such as.

  Further, in the conventional example described in Patent Document 3, it is necessary to perform balance adjustment before the process of integrating the rotor, the end plate, and the balance adjustment weight by rivets, and the unbalance amount specified after the integration is reduced. If it is over, it is difficult to readjust and keep it below the specified unbalance amount. In addition, the rotor core requires a rivet hole for passing a rivet. Compared to the case where there is no rivet hole, even if the rivet hole is provided at a position that does not affect the flow of magnetic flux, there is an effect of lowering the efficiency. There are unresolved issues.

Moreover, in the conventional example described in Patent Document 4, balance adjustment is performed by grinding a metal part while reducing the weight of the rotor by using a resin ring. Therefore, there is an unresolved problem that the metal part needs to be ground and there is a risk of entering the rotor core on which the grinding powder is laminated, which causes a problem in quality.
Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and appropriately performs balance adjustment without performing cutting that generates cutting waste such as drilling powder and grinding powder. It is an object of the present invention to provide a rotor of a permanent magnet type rotating electric machine capable of achieving the above and a balance adjustment method thereof.

In order to achieve the above object, a rotor of a permanent magnet type rotating electrical machine according to the first aspect of the present invention is mounted on a rotor core holding a permanent magnet and at least one end in the axial direction of the rotor core, and is used for balance adjustment. And a balance ring having a plurality of protrusions capable of caulking and fixing the weight.
In the rotor of the permanent magnet type rotating electric machine according to the second aspect of the present invention, the balance ring is made of any one of aluminum, an aluminum alloy, an aluminum casting, and an aluminum alloy casting. It is a feature.

Furthermore, the rotor of the permanent magnet type rotating electric machine according to the third aspect of the present invention is characterized in that the balance ring is made of cast iron.
Furthermore, the rotor balance adjustment method of the permanent magnet type rotating electrical machine according to the fourth aspect of the present invention includes a plurality of balance adjustment weights that can be caulked and fixed to at least one end portion in the axial direction of the rotor core holding the permanent magnet. A balance ring having a protrusion is attached, and at least one of a balance adjustment method for caulking and fixing a balance adjustment weight to the protrusion of the balance ring and a balance adjustment method for cutting the protrusion of the balance ring is selected and balanced. It is characterized by making adjustments.

  According to the present invention, the balance ring to be attached to at least one end of the rotor core in the axial direction is formed with the plurality of protrusions capable of caulking and fixing the balance adjustment weight, so that the balance ring and the rotor core are attached to the rotary shaft. The balance adjustment can be easily performed in a short time without generating cutting waste such as drilling powder or grinding powder by attaching a balance adjusting weight to at least the protrusion of the balance ring or cutting the protrusion itself. The effect is obtained.

It is sectional drawing which shows the permanent magnet type rotary electric machine which shows one Embodiment of this invention. It is a perspective view which shows the rotor of FIG. It is a perspective view of the state which removed the balance ring of FIG. It is a P direction arrow directional view of FIG. It is a perspective view of a balance ring applicable to the present invention. It is a disassembled perspective view of the balance ring of FIG. It is a front view of the balance ring of FIG. It is a perspective view which shows a prior art example. It is a perspective view which shows the end plate applicable to a prior art example. It is a front view of the end plate of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing a permanent magnet type synchronous motor as a permanent magnet type rotating electrical machine showing an embodiment of the present invention.
In FIG. 1, a permanent magnet type synchronous motor 1 has an interior permanent magnet (IPM) structure.

The permanent magnet type synchronous motor 1 has a cylindrical frame 2, a stator 3 is disposed on the inner peripheral side of the cylindrical frame 2, and a predetermined air gap is provided on the inner peripheral side of the stator 3. Opposing rotors 4 are arranged. The rotor 4 is attached to the rotating shaft 5.
The stator 3 has a stator core 6 formed by stacking axially laminated stator core plates made by punching a high-permeability electromagnetic steel plate. The stator core 6 has a slot extending in the axial direction on the inner peripheral surface side. 7 is formed, and an exciting coil 8 is wound in the slot 7. Here, either the concentrated winding or the distributed winding may be adopted as the winding method of the exciting coil 8.

  On the other hand, as shown in FIG. 2, the rotor 4 includes a rotor core 13 having, for example, six magnetic poles 12 in which rotor core plates made by punching a high-permeability electromagnetic steel sheet are laminated in the axial direction. The rotor core 13 includes a plurality of, for example, six magnet insertion holes 14 formed so as to penetrate in the axial direction, and permanent magnets inserted in the magnet insertion holes 14 so that the magnetic poles 12 adjacent in the circumferential direction have different polarities. 15. Here, the permanent magnet 15 is composed of a rare earth magnet.

  As shown in FIG. 2, the rotor 4 prevents the balance ring 16 from rotating in the circumferential direction and moving in the axial direction by shrink fitting or press-fitting on both axial end surfaces of the rotor core 13 in the rotating shaft 5. It is firmly fixed. The balance ring 16 has a donut-shaped disk 18 made of aluminum or aluminum alloy in which a center hole 17 having a circular cross section through which the rotary shaft 5 is inserted is formed.

  This disk 18 is provided with a contact surface between the rotor core 13 and, as shown in FIG. 4 and FIG. 5, from the rotor core side 13 side or the projection side 20 side in the center hole 17 portion, The bush 19 is fixed. Further, for example, twelve protrusions 20 are formed integrally on the circumference passing through the substantially central portion between the bush 19 and the outer peripheral edge of the circular plate 18 so as to protrude on the opposite side to the rotor core 13. The protrusion 20 is formed so that the balance adjustment weight 21 can be fixed by caulking, and without using a special cutting process that generates cutting waste such as drilling powder or grinding powder. It can be easily cut.

Here, the disc 18 and the bush 19 are formed by embedding the bush 19 in the disc 18 by die-casting aluminum or an aluminum alloy while the bush 19 is mounted on a die-cast mold.
As shown in FIG. 2, the balance adjustment weight 21 is formed in a cylindrical shape having a center hole into which an arbitrary protrusion 20 can be inserted.

Next, the operation of the above embodiment will be described.
In order to assemble the rotor 4, first, as shown in FIG. 3, the rotor core 13 composed of the electromagnetic steel plates laminated on the rotating shaft 5 is mounted, and thereafter or before that, in the magnet insertion hole 14 of the rotor core 13, The permanent magnet 15 is inserted.
Thereafter, with the balance ring 16 at both ends of the rotor core 13 in the axial direction of the rotary shaft 5 and the flat surface thereof being in contact with the axial end surface of the rotor core 13, circumferential rotation and axial movement are not allowed. The assembly of the rotor 4 is completed by firmly fixing it as possible.

Thus, by attaching the balance ring 16 to both ends of the rotor core 13 in the axial direction, the openings of the magnet insertion holes 14 formed in the rotor core 13 are closed, and the positioning of the permanent magnet 15 in the axial direction is closed. It can be performed.
When the assembly of the rotor 4 is completed, the rotor 4 is attached to the balance machine. At this time, the bearing mounting portions 5a and 5b of the rotary shaft 5 are attached to the balance machine with the fulcrum as a fulcrum.

  And the unbalance amount of a rotary body is measured by rotating the rotor 4 with a fixed rotational speed with a balance machine. Based on the measured unbalance amount, the balance adjustment is performed so that the two-plane balance shown in JIS B0905 or the like is less than the allowable value corresponding to the maximum rotational speed used by the rotating machine or the mass of the rotating body. The balance adjustment may be a balance adjustment method in which the balance adjustment weight 21 is attached to the protrusion 20 and fixed by caulking as shown in FIG. 2, or a balance adjustment method in which the protrusion 20 itself is cut with a sheet metal tool such as a metal cutter, Furthermore, the balance adjustment is performed by applying a balance adjustment method for both mounting the balance adjustment weight 21 and cutting the protrusion 20.

As described above, according to the above-described embodiment, the balance adjustment is performed using the protrusions 20 of the balance ring 16 provided with the plurality of protrusions 20 at equal intervals in the circumferential direction. be able to. In addition, since balance adjustment can be performed when the assembly of the rotor 4 is completed, accurate balance adjustment can be performed.
Further, the balance adjustment method includes a balance adjustment method for caulking and fixing the balance adjustment weight 21 to the protrusion 20, a balance adjustment method for cutting the protrusion 20 at a necessary location, and mounting of the balance adjustment weight 21 and cutting of the protrusion 20. Therefore, it is possible to select a balance adjustment method for performing both of the above and the fine balance adjustment.

  Incidentally, in the conventional example, as shown in FIGS. 6 to 8, end plates 31 that simply fix both axial ends of the rotor core 13 are used without using the balance ring 16 of this embodiment. In this case, as shown in FIGS. 7 and 8, the end plate 31 is formed with a groove 32 formed on the circumferential surface serving as a guide for the balance adjustment position or a groove 33 formed on the end surface, or for balance adjustment. A screw tap 34 for attaching a weight is formed. Then, based on the measured unbalance amount, it is necessary to perform a cutting operation by special machining on a part of the groove 32 or 33 or an operation such as fixing a balance adjusting screw to the screw tap 34 to determine the balance adjusting position. Is difficult, and the balance adjustment takes time. In addition, it takes time to clean the cutting waste generated by the cutting process, and if the cleaning work is insufficient, the cutting waste enters the outer peripheral portion of the rotor 4 and the bearing mounting portions 5a, 5b, etc. There is also a risk of becoming.

In order to prevent such problems, the balance adjustment work requires careful and accurate, etc., so that the work time is prolonged and the products of workers and machines vary, resulting in unstable quality. The problem is occurring.
However, in the present embodiment, as described above, the balance adjustment work merely performs caulking and fixing of the balance adjustment weight 21 to the protrusion 20, cutting of the protrusion 20, etc., and no cutting waste is generated. Accurate balance adjustment can be performed in time. In particular, even when the protrusion is cut, the cut protrusion has a visible size, so there is almost no fear of entering the outer peripheral portion of the rotor 4 or the bearing mounting portions 5a and 5b. Even so, since it is easy to find and remove this, there is no possibility that grinding scraps are accumulated and the quality is not lowered as in the above-described prior art.

In the above-described embodiment, the description has been given of the case where the balance ring 16 is attached to each end of the rotor core 13 in the axial direction on the rotating shaft 5. However, the present invention is not limited to this. You may make it mount | wear with the end plate which mounts the ring 16 and does not perform balance adjustment to the other.
Moreover, in the said embodiment, although the case where the balance ring 16 was comprised by die-casting aluminum or aluminum alloy was demonstrated, it is not limited to this, Aluminium or aluminum alloy is cut and processed into a disk The balance ring 16 may be configured by forming a projection fitting hole in the circular plate 18 and fitting the projection 20 in the projection fitting hole. Further, the balance ring 16 may be formed by casting cast iron. In this case, the bush 19 can be omitted.

Moreover, in the said embodiment, although the center hole of the disc 18 and the internal peripheral surface of the bush 19 were circular, it was not limited to this, The cross section of the balance ring mounting part of the rotating shaft 5 is demonstrated. When the shape is an arbitrary shape such as a dihedral width shape, a rectangular shape, an elliptical shape or the like that prevents rotation in the circumferential direction, the shape can be adjusted to these shapes.
Moreover, although the case where the number of magnetic poles of the rotor 4 is 6 has been described in the above embodiment, the present invention is not limited to this and can be set to an arbitrary number of magnetic poles.

Moreover, in the said embodiment, although the case where one magnetic pole was formed with one permanent magnet 15 was demonstrated, it is not limited to this, A permanent magnet is arrange | positioned in V shape, U shape, etc. You can also.
Moreover, although the case where the rotor 4 has an embedded magnet structure has been described in the above embodiment, the present invention is not limited to this, and a surface magnet structure in which permanent magnets are arranged on the outer peripheral surface can also be used.
In the above embodiment, the case where the permanent magnet type synchronous motor is applied as the permanent magnet type rotary electric machine has been described. However, the present invention is not limited to this, and the present invention is also applied to other types of permanent magnet type rotary electric machines. Can be applied.

DESCRIPTION OF SYMBOLS 1 ... Permanent magnet type synchronous motor 2 ... Cylindrical frame 3 ... Stator 4 ... Rotor 5 ... Rotating shaft 5a, 5b ... Bearing mounting part 6 ... Stator core 7 ... Slot 8 ... Excitation coil 12 ... Magnetic pole 13 ... Rotor core 14 ... Magnet insertion hole DESCRIPTION OF SYMBOLS 15 ... Permanent magnet 16 ... Balance ring 17 ... Center hole 18 ... Disc 19 ... Bush 20 ... Protrusion 21 ... Weight for balance adjustment

Claims (4)

  A permanent magnet type rotation comprising: a rotor core holding a permanent magnet; and a balance ring which is attached to at least one end portion in the axial direction of the rotor core and has a plurality of protrusions capable of caulking and fixing a balance adjustment weight. Electric rotor.   The rotor of a permanent magnet type rotating electric machine according to claim 1, wherein the balance ring is made of any one of aluminum, an aluminum alloy, an aluminum casting, and an aluminum alloy casting.   The rotor of the permanent magnet type rotating electric machine according to claim 1, wherein the balance ring is made of cast iron. A balance ring having a plurality of protrusions capable of caulking and fixing a balance adjusting weight is attached to at least one end portion of the rotor core holding the permanent magnet in the axial direction.
The balance adjustment is performed by selecting at least one of a balance adjustment method for caulking and fixing a balance adjustment weight to the protrusion of the balance ring and a balance adjustment method for cutting the protrusion of the balance ring. A method for adjusting the balance of a rotor of a magnet-type rotating electrical machine.

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