JP2012157150A - Permanent magnet type rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet type rotary electric machine which reduces a thickness between an outer periphery of a rotor core and a slot to improve the motor efficiency and also reduce stress occurring at the outer peripheral side of the rotor core.SOLUTION: In order to solve the above problem, a slit is provided at a part of a surface where a permanent magnet contacts with a rotor core and a supporting point for moving the permanent magnet is provided at the inner peripheral side of the rotor core relative to a centroid of the permanent magnet.

Description

  The present invention relates to a permanent magnet type rotating electrical machine, and more particularly, to a permanent magnet type rotating electrical machine suitable for, for example, a motor for a railway vehicle in which a permanent magnet is employed as a magnetic source in a rotor.

  Winding generators and induction motors have been used as rotating electrical machines used in railway vehicles, but in recent years they have become smaller and lighter due to the higher performance and lower prices of permanent magnets and the spread of high-performance inverters. Motivation to adopt a permanent magnet type rotating electrical machine that enables higher efficiency and higher efficiency is increasing.

  FIG. 1 shows a configuration of a general railway vehicle motor. As shown in the drawing, the motor for a railway vehicle includes a stator core 2 fixed to a casing 3 and wound with a stator coil 6, and a rotor core 1 that rotates integrally with a shaft 4. The casing 3 is configured to be opposed to each other with a predetermined gap and supported by a shaft 4 via a bearing 5. The rotor core 1 and the stator core 2 are formed by laminating a plurality of silicon steel plates in the axial direction.

  FIG. 2 shows a cross section taken along the line A-A 'of FIG. As shown in the figure, a slot 8 for inserting a permanent magnet extends in the axial direction in the rotor core 1 and a plurality of C-shaped slots are provided, and each of the slots 8 has a permanent magnet. 7 is inserted and installed. In addition, a stator coil 6 is provided in the stator core 2, and the rotor core 1 and the shaft 4 are rotated by applying a magnetic field change to the stator coil 6 (Patent Document 1). And 2).

JP 2006-333656 A JP 2010-161883 A

  Usually, the rotor core 1 in which the permanent magnet 7 is inserted rotates at a high speed during operation. For this reason, centrifugal force acts on the rotor core 1, and force that moves toward the outer peripheral side acts on the permanent magnet 7. Since this force is received on the outer peripheral side of the surface of the slot 8 of the rotor core 1, in a conventional configuration in which a thin portion is generated between the slot 8 on the outer peripheral side of the rotor core 1, A high tensile stress is generated at a thin portion of the outer periphery of the rotor core 1.

  This will be described with reference to FIG. As shown in the drawing, since the permanent magnet 7 is conventionally inserted into a slot 8 provided in the rotor core 1, there is no gap between the rotor core 1 and the permanent magnet 7, and the permanent magnet is rotated when the motor rotates. The load applied to 7 is received by the B and B ′ planes in the figure.

  Therefore, as shown in the drawing, stress concentrates on a thin portion between the outer periphery side of the rotor core 1 in which the permanent magnet 7 is inserted.

  In order to prevent this, the thickness between the outer periphery of the rotor core 1 and the slot 8 may be increased, but this leads to a reduction in motor efficiency.

  As described above, the thinner the thickness between the rotor core 1 and the slot 8 on the outer peripheral side is, the better the efficiency of the motor is. Therefore, how to reduce the thickness and reduce the stress is an issue. It has become.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and an object of the present invention is to reduce the thickness between the slots on the outer periphery side of the rotor core and improve the efficiency of the motor, and to improve the rotor core. It is providing the permanent magnet type rotary electric machine which can reduce the stress which generate | occur | produces in the outer peripheral side.

In order to achieve the above object, a permanent magnet type rotating electrical machine according to the present invention has a stator having a stator core around which a stator coil is wound, a stator and a stator that are arranged to face each other with a predetermined gap. A rotor having a rotor core that rotates integrally, and a plurality of slots for inserting permanent magnets are provided in the rotor core so as to extend in the axial direction. In the permanent magnet type rotating electrical machine in which the permanent magnet is inserted, a slit is provided in a part of a surface where the permanent magnet and the rotor core contact, and a fulcrum for the permanent magnet to move is used as a center of gravity of the permanent magnet. Than the inner circumference of the rotor core,
Alternatively, the slot and the permanent magnet of the rotor core are formed in a cross-sectional shape with a fulcrum projecting on the inner peripheral side, and the inner peripheral side of the permanent magnet in the cross-sectional shape is in a direction in which centrifugal force acts. On the other hand, it is formed so that resistance becomes large.

  According to the present invention, it is possible to reduce the stress generated on the outer periphery side of the rotor core while reducing the thickness between the slots on the outer periphery side of the rotor core and improving the efficiency of the motor. Thus, a permanent magnet type rotating electrical machine can be obtained in which the size of the rotating electrical machine can be reduced and the weight can be reduced.

It is sectional drawing which shows the structure of the motor for rail vehicles to which this invention is applied. It is sectional drawing which follows the A-A 'line of FIG. It is the fragmentary sectional view of the rotor core which showed the surface which bears the load in the conventional structure, and the stress generation | occurrence | production site | part. It is the fragmentary sectional view of the rotor core which showed the surface which bears the load in the structure of Example 1 of the permanent magnet type rotary electric machine of this invention, and the stress generation | occurrence | production site | part. FIG. 5 is a partial cross-sectional view of a rotor core showing a load-bearing surface in the configuration of the modification of the example shown in FIG. 4. It is the fragmentary sectional view of the rotor core which showed the surface which bears the load in the structure of Example 2 of the permanent magnet type rotary electric machine of this invention. It is a fragmentary sectional view of the rotor core which showed the surface which bears the load in the structure of the modification of the example shown in FIG. It is a fragmentary sectional view of the rotor core which showed the surface which bears the load in the structure of the other modification of the example shown in FIG. It is the fragmentary sectional view of the rotor core which showed the surface which bears the load in the structure of Example 3 of the permanent magnet type rotary electric machine of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. Incidentally, the same reference numerals are used for the same reference numerals as before, and the description thereof is omitted.

  FIG. 4 shows Example 1 of the permanent magnet type rotating electrical machine of the present invention.

As shown in the drawing, formed in this embodiment, the length of the short side in the slot 8 for the permanent magnet insertion, increasing the length of the inner circumferential side (l ₁₎ from the outer circumferential side length (l ₂₎ When the permanent magnet 7 is inserted into the slot 8, the permanent magnet 7 is arranged so that a slit 9 is formed between the permanent magnet 7 and the slot 8 on the outer peripheral side of the slot 8.

  That is, the slit 9 is formed on the outer peripheral side of the slot 8 with the final end where the permanent magnet 7 and the rotor core 1 are in contact with each other as a fulcrum C, and from there toward the outer peripheral side. A permanent magnet 7 is inserted and disposed in the slit 9 so that a slit 9 is formed.

  Moreover, the fulcrum C is located on the inner side of the center of gravity G of the permanent magnet 7, that is, on the inner side of the vertical line passing through the center of gravity G with respect to the long side in the cross section of the permanent magnet 7 (left side of the vertical line in FIG. 4). is doing.

  In the present embodiment having such a configuration, the slit 9 as described above is provided, and the fulcrum C that comes into contact with the permanent magnet 7 is arranged on the inner side of the center of gravity G of the permanent magnet 7 so as to receive the centrifugal force accompanying the rotation. In this case, the permanent magnet 7 moves toward the slit 9 with the fulcrum C as an axis, and the fulcrum C, the surface B ′, and the surface D are responsible for the force generated in the permanent magnet 7.

Thus, in this embodiment, the load which has been received by the surface B of the slot 8 shown in Figure 3 of the prior art, it is possible to disperse the surface D and surface B ₀ in FIG. 4, the rotor core 1 High stress generated in a thin portion between the outer peripheral slot 8 can be reduced.

  As described above, the permanent magnet 7 is about to move to the outer peripheral side due to the centrifugal force during operation, so that the stress generated on the outer periphery of the rotor core 1 can be reduced, and the thickness of the outer periphery of the rotor core 1 can be reduced. Is possible. As a result, the efficiency of the motor is improved, and the motor efficiency is improved, so that the physique of the motor can be further reduced, and the weight of the motor can be expected.

  FIG. 5 shows a modification of the embodiment shown in FIG. In this embodiment shown in the figure, the outer peripheral side of the permanent magnet 7 is circular and larger than the inner peripheral side, and the center of gravity G is outer than the position of the center of gravity G in FIG. 4 (the center position of the permanent magnet 7). It is arranged on the side.

  By comprising in this way, the permanent magnet 7 becomes easy to move to the slit 9 side, the load received by the surface D increases, and the further stress fall can be anticipated. In addition, by enlarging the outer peripheral side of the permanent magnet 7, the cooling of the permanent magnet 7 is improved and the temperature rise is prevented.

  FIG. 6 shows a second embodiment of the permanent magnet type rotating electrical machine of the present invention.

As shown in the figure, in this embodiment, the slot 8 and the permanent magnet 7 of the rotor core 1 are formed in a cross-sectional shape with a fulcrum C projecting on the inner peripheral side, and the permanent magnet 7 is moved to the outer periphery by centrifugal force. A surface E is provided for receiving a load applied when moving to the side. That is, the inner surface of the permanent magnet 7 having a cross-sectional shape is formed with a surface E in which the resistance is increased in the direction in which the centrifugal force is applied. The load is increased, and the stress generated in the thin portion between the outer peripheral side slot 8 of the rotor core 1 is reduced, and the load applied to the surfaces B and B ′ shown in FIG. Can be reduced.

Further, part of the rotor core 1 of the above-mentioned plane E, since the wall thickness L ₁ is thicker than the thickness L ₂ in the thin portion, high stress even when subjected to large load is not generated. Further, the stress generated on the outer periphery of the rotor core 1 can be reduced because the load received on the surfaces B and B ′ is reduced.

  FIG. 7 shows a modification of the embodiment shown in FIG. In this embodiment shown in the figure, the slot 8 and the permanent magnet 7 of the rotor core 1 are formed in a cross-sectional shape with a fulcrum C projecting on the inner peripheral side, and further the slot 8 on the outer peripheral side of the rotor core 1. A slit 9 is provided between the permanent magnet 7 and the permanent magnet 7 so as not to contact the outer peripheral side of the rotor core 1.

  With this configuration, the load received on the surface B ′ of FIG. 3 of the conventional example is reduced, and the surface receiving the load of the surface B is also reduced.

  Thereby, it is possible to receive a large load on the thick surface E, and to reduce the stress generated on the outer peripheral side of the rotor core 1.

  FIG. 8 shows another modification of the embodiment shown in FIG. In this embodiment shown in the figure, the slot 8 and the permanent magnet 7 of the rotor core 1 are formed in a cross-sectional shape with a fulcrum C projecting on the inner peripheral side, and a slit 9 is provided in the slot 8; and The permanent magnet 7 (in the thick permanent magnet 7) on the side away from the outer periphery of the rotor core 1 is configured to have a center of gravity.

  With this configuration, a force is generated in the permanent magnet 7 to move in the direction of the arrow in the figure, but the deformation is absorbed by the slit 9 in the slot 8, and the permanent magnet 7 and the rotor core 1 The outer peripheral portion is not in contact, and the stress generated on the outer peripheral portion of the rotor core 1 can be reduced.

  FIG. 9 shows a third embodiment of the permanent magnet type rotating electric machine according to the present invention.

  As shown in the figure, in this embodiment, the slot 8 and the permanent magnet 7 of the rotor core 1 are provided with a step formed by forming the outer peripheral side narrower and the inner peripheral side thicker, and the outer periphery formed narrower. A slit 9 is provided in a slot 8 near the tip of the permanent magnet 7 on the side.

  With this configuration, it is possible to receive a load accompanying rotation at the above-described stepped portion, and it is possible to reduce the load received on the surface B ′ of FIG. 3 of the conventional example, and the outer periphery of the rotor core 1 The stress generated in the part can be reduced.

  As described above, according to the present invention described in the various embodiments, the stress generated on the outer periphery of the rotor core can be reduced as the permanent magnet tries to move to the outer peripheral side by the centrifugal force during operation, and the rotor core can be reduced. The thickness of the outer periphery can be reduced, and the efficiency of the rotating electrical machine is improved. Therefore, by improving the efficiency of the rotating electrical machine, it is possible to further reduce the size of the rotating electrical machine and reduce the weight.

  DESCRIPTION OF SYMBOLS 1 ... Rotor iron core, 2 ... Stator iron core, 3 ... Casing, 4 ... Shaft, 5 ... Bearing, 6 ... Stator coil, 7 ... Permanent magnet, 8 ... Slot, 9 ... Slit.

Claims (9)

A stator having a stator core around which a stator coil is wound, and a rotor having a rotor core that is disposed to face the stator with a predetermined gap and rotates integrally with a shaft, In the rotor core, a permanent magnet insertion slot is provided with a plurality of slots extending in the axial direction, and a permanent magnet is inserted into each slot.
A slit is provided in a part of the surface where the permanent magnet and the rotor core contact, and a fulcrum for the permanent magnet to move is provided on the inner peripheral side of the rotor core from the center of gravity of the permanent magnet. Permanent magnet type rotating electrical machine characterized by In the permanent magnet type rotating electrical machine according to claim 1,
The slit is formed so that the length of the short side of the slot for inserting the permanent magnet is larger on the outer peripheral side than the inner peripheral side, and the slot is inserted when the permanent magnet is inserted into the slot. The permanent magnet type rotating electrical machine is formed between the permanent magnet and the slot on the outer peripheral side of the motor. In the permanent magnet type rotating electrical machine according to claim 1,
The slit is a slot formed on the outer peripheral side of the slot for inserting the permanent magnet, with the final end where the permanent magnet and the rotor core are in contact as a fulcrum, and widening toward the outer periphery from the fulcrum. The permanent magnet rotating electrical machine is formed by inserting and arranging the permanent magnet. In the permanent magnet type rotating electrical machine according to claim 1,
The said fulcrum C is located inside the perpendicular drawn so that it may pass through a gravity center with respect to the long side in the cross section of the said permanent magnet 7, The permanent-magnet-type rotary electric machine characterized by the above-mentioned. In the permanent magnet type rotating electrical machine according to claim 1,
A permanent magnet type rotating electrical machine, wherein an outer peripheral side of the permanent magnet is formed in an arc shape and larger than an inner peripheral side, and a center of gravity of the permanent magnet is arranged on an outer peripheral side from a center position of the permanent magnet. A stator having a stator core around which a stator coil is wound, and a rotor having a rotor core that is disposed to face the stator with a predetermined gap and rotates integrally with a shaft, In the rotor core, a permanent magnet insertion slot is provided with a plurality of slots extending in the axial direction, and a permanent magnet is inserted into each slot.
The slot and the permanent magnet of the rotor core are formed in a cross-sectional shape with a fulcrum projecting on the inner peripheral side, and the inner peripheral side of the permanent magnet in the cross-sectional shape is in a direction in which centrifugal force acts. A permanent magnet type rotating electrical machine characterized in that the resistance is increased. In the permanent magnet type rotating electrical machine according to claim 6,
A permanent magnet, wherein a slit is provided between the slot on the outer peripheral side of the rotor core and a permanent magnet so that the permanent magnet does not contact the outer peripheral side of the rotor core. Rotary electric machine. In the permanent magnet type rotating electrical machine according to claim 6,
The permanent magnet is formed in a thick cross-sectional shape on the inner peripheral side from the outer peripheral side, has a center of gravity position in the thick permanent magnet 7, and is provided with a slit in the slot. A permanent magnet type rotating electrical machine. A stator having a stator core around which a stator coil is wound, and a rotor having a rotor core that is disposed to face the stator with a predetermined gap and rotates integrally with a shaft, In the rotor core, a permanent magnet insertion slot is provided with a plurality of slots extending in the axial direction, and a permanent magnet is inserted into each slot.
The slot of the rotor core and the permanent magnet are provided with a step generated by forming the outer peripheral side narrower and the inner peripheral side thicker, and the slot near the tip of the permanent magnet on the outer peripheral side formed thin Is provided with a slit, and a permanent magnet type rotating electrical machine.

Images