JP2008295178A - Rotor structure of permanent magnet rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor structure of a permanent magnet rotating electric machine which is improved in resistance properties for high-speed rotation, enhanced in the transmission of rotation torque, and high in productivity. <P>SOLUTION: A rotating shaft 1 has a plurality of recessed grooves 1a extendedly formed along the axial direction on its surface, and a permanent magnet is extended in the axial direction, and formed into a shape of an arc which has the same width in the radial direction along the external peripheral surface of the rotating shaft 1. The permanent magnet includes a plurality of first magnet pieces 2 arranged between the adjacent recessed grooves 1a on the surface of the rotating shaft 1, and a plurality of second magnet pieces 3 which are extended in the axial direction, of which the external peripheral surfaces located outside the radial direction are formed into shapes of arcs having the same outside diameters as those of the first magnet pieces 2, and the radial widths are formed thick in thickness compared with those of the first magnet pieces 2, and which are arranged between the adjacent first magnet pieces 2 so as to be inserted into the recessed grooves 1a at their portions located at an axial core side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotor structure of a permanent magnet type rotating machine, and more particularly to a rotor structure of a permanent magnet type synchronous motor and a permanent magnet type synchronous generator that rotate at an ultra high speed.

  Conventionally, as a rotor structure mainly used for an ultra-high speed permanent magnet type synchronous motor, a permanent magnet type synchronous generator, etc., a cylindrical permanent magnet (also called a ring magnet) or a cylindrical permanent magnet is used in the circumferential direction. There is a rotor structure obtained by press fitting, shrink fitting, or cold fitting with a cylindrical non-magnetic high-strength material (hereinafter referred to as a reinforcing ring) (see, for example, Patent Document 1).

  FIG. 7 shows an example of a conventional rotor structure, in which a reinforcing ring 104 is provided on a cylindrical permanent magnet 102 disposed on the outer periphery of a rotating shaft 101.

  In the rotor structure as shown in FIG. 7, the permanent magnet is prevented from being damaged by providing a tightening margin on the inner diameter side of the permanent magnet so that a tensile stress exceeding the allowable tensile stress of the permanent magnet does not act at the time of high speed rotation. ing.

  In the rotor structure in which the cylindrical permanent magnet is divided into a plurality of magnet pieces and the reinforcing ring is fitted on the outer periphery of the divided permanent magnet, the permanent magnet is divided in the circumferential direction. The tensile stress acting on the inner diameter side of the permanent magnet is reduced by centrifugal force compared to the magnet. The tensile stress acting on the inner diameter side of the permanent magnet due to centrifugal force is reduced as the number of divisions of the permanent magnet is increased.

  In such a conventional rotor structure, the rotational torque acting on the permanent magnet is secured by taking up a tightening force so that the shaft and the permanent magnet are not separated by centrifugal force during high-speed rotation, or by adhering the shaft and the permanent magnet. Is transmitted to the rotating shaft. Examples of the reinforcing ring include high-strength fibers such as carbon fibers and nonmagnetic metal wires for reducing eddy current loss.

  However, in a rotor structure using a cylindrical permanent magnet, if the adhesive that bonds the cylindrical permanent magnet and the rotating shaft is peeled off due to the heat generated by the rotor or the inertial force during rapid acceleration / deceleration, the permanent magnet There is a risk that the rotational torque acting on the rotating shaft will not be transmitted to the rotating shaft. Therefore, a rotor structure is also disclosed in which a groove for torque transmission is provided on a rotating shaft or the like, and rotational torque acting on the permanent magnet is transmitted to the shaft by using magnets having different thicknesses (for example, Patent Document 2).

  In such a rotor structure, the rotational torque acting on the permanent magnet can be transmitted to the rotating shaft, so that the motor drive can be continued even if the adhesive is peeled off. Specifically, the thickness difference dimension between the thick part and the thin part of the permanent magnet is set so as to be larger than the gap formed between the permanent magnet and the yoke. Enters the thin part of the yoke and fits in, so that high torque can be transmitted.

  For example, in the above-described Patent Document 2, the shape of the switching portion between the thick portion and the thin portion of the permanent magnet is formed in a wave shape without an acute angle, thereby preventing stress concentration in the permanent magnet and the yoke. Further, even when the gap between the inner circumference of the magnet and the outer circumference of the yoke is changed due to a temperature change, the deformation of the magnet can be suppressed to be small, and damage due to thermal expansion can be prevented.

  On the other hand, there is also a rotor structure in which a cylindrical permanent magnet is press-fitted, shrink-fitted, or cold-fitted with a reinforcing ring in contrast to the above-described rotor structure using a cylindrical permanent magnet (see, for example, Patent Document 3).

  In such a rotor structure using a cylindrical permanent magnet, as in the case of using the cylindrical permanent magnet described above, a tensile stress exceeding the allowable tensile stress of the permanent magnet is applied to the inner diameter side of the permanent magnet during high-speed rotation. The permanent magnet is prevented from being damaged by providing a tightening margin so as not to act.

  The reinforcing ring and the rotary shaft are press-fitted, shrink-fitted, cold-fitted or welded at both ends of the permanent magnet. Then, the rotational torque acting on the permanent magnet is transmitted to the rotating shaft by taking the tightening allowance so that the reinforcing ring and the permanent magnet or the reinforcing ring and the rotating shaft are not separated by the centrifugal force at high speed rotation. Yes.

  In such a rotor structure using a columnar permanent magnet, even if the outer diameter and the length of the permanent magnet are the same, compared with the case where the cylindrical permanent magnet described above is used, it is more resistant to centrifugal force. It has the advantages of excellent resistance and a large magnetic flux.

Japanese Patent Laid-Open No. 02-241339 Japanese Patent Laid-Open No. 09-056092 JP 2002-142393 A

  However, in the rotor structure using the cylindrical permanent magnet described above, the rotating shaft and the permanent magnet are prevented from acting on a tensile stress exceeding the allowable tensile stress of the permanent magnet, or depending on the centrifugal force or the operating temperature condition. However, it is necessary to increase the tightening margin in order to prevent separation, and it is necessary to raise the press-fitting or shrink-fitting temperature to a temperature that is practically difficult, in other words, to a temperature unsuitable for mass production. there were. In order to increase the tightening allowance, it is necessary to make the temperature practically difficult even in the case of cold fitting, and there is a concern that the improvement of productivity may be hindered.

  Further, in a rotor structure that transmits the rotational torque of the permanent magnet to the shaft by bonding the shaft and the permanent magnet, the function of the adhesive may be reduced in a high temperature environment (100 ° C. or higher). is there. Once the permanent magnet is peeled off from the rotating shaft due to a decrease in the function of the adhesive, the bonded state will not be restored.Therefore, in the high temperature environment, the rotating shaft and the permanent magnet may be separated so that torque cannot be transmitted to the shaft. there were.

  Further, when high strength fibers are used as the reinforcing ring, the high strength fibers have a small coefficient of thermal expansion and are difficult to shrink fit. Therefore, press fitting or cold fitting of the permanent magnets is performed. However, since the thermal expansion coefficient of permanent magnets is about half that of iron, it is difficult to make a large tightening allowance, preventing the application of tensile stress exceeding the allowable tensile stress of permanent magnets, centrifugal force and use It was difficult to prevent the shaft and the permanent magnet from separating regardless of the temperature conditions.

  Further, in the rotor structure as described in Patent Document 2, since the permanent magnet is divided in the circumferential direction, the stress caused by the centrifugal force of the permanent magnet is reduced and the divided permanent magnet Since the magnet piece is a structure having a thickness difference (thick part and thin part), the meshing with the rotating shaft is good. However, since the permanent magnet has a thick portion and a thin portion in one magnet piece, there is a problem that the magnet is easily damaged due to a difference in centrifugal stress due to a centrifugal force when the thick portion and the thin portion are rotated at high speed. Was considered. Furthermore, because there are thick and thin portions in the magnet piece of one permanent magnet, the gap size formed between the opposing rotating shafts differs depending on the machining dimensional accuracy, and this gap size difference is due to adhesive filling. There was a problem that the adhesive strength was not stable due to a difference in the pressing force at the time.

  Furthermore, in the rotor structure as described in Patent Document 3, if the tightening margin is set so that a tensile stress exceeding the allowable tensile stress of the permanent magnet does not work, the tightening margin increases, and the press-fitting or shrink-fit temperature is reduced. It may be necessary to raise the temperature to a practically difficult temperature, in other words, a temperature unsuitable for mass production, and there is a concern that improvement in productivity may be suppressed. This is the same even when a cold fit is performed.

  Moreover, when using a cylindrical permanent magnet, a rotating shaft will be parted on both sides of a permanent magnet. As a method of fixing the rotating shaft to both ends of the permanent magnet, there are a method in which the rotating shaft is press-fit, shrink-fitted, or cold-fitted with a reinforcing ring, or the rotating shaft and the reinforcing ring are fixed by welding. Care was required for the rigidity and the work was complicated.

  When the rotary shaft is press-fit, shrink-fitted, or cold-fitted with a reinforcing ring, the rotational torque acting on the permanent magnet is transmitted to the reinforcing ring and further transmitted to the rotating shaft. If the allowance is taken so that the ring and the rotating shaft, and the reinforcing ring and the permanent magnet are not separated from each other, the allowance becomes large, and the press-fit or shrink-fit temperature is a temperature that is practically difficult, in other words, a temperature unsuitable for mass production. It may be necessary to raise it to a maximum. This is the same even when performing cold fitting, and there is a possibility that improvement in productivity may be hindered.

  In view of the above, an object of the present invention is to provide a rotor structure of a permanent magnet type rotary machine that improves resistance to high-speed rotation, is excellent in transmission of rotational torque, and has high productivity.

  A rotor structure of a permanent magnet type rotating machine according to a first invention for solving the above-mentioned problems has a permanent magnet disposed in a cylindrical shape on an outer peripheral portion of a rotating shaft, a cylindrical shape, and the permanent structure. In a rotor structure of a permanent magnet type rotating machine provided with a reinforcing member disposed on the outer periphery of the magnet, the rotating shaft has a plurality of concave grooves extending in the axial direction on the surface, A plurality of permanent magnets that extend in the axial direction and are formed in an arc shape along the outer peripheral surface of the rotating shaft, have the same radial width, and are arranged between adjacent concave grooves on the surface of the rotating shaft. The first magnet piece and an outer circumferential surface extending in the axial direction and positioned radially outward have an arc shape having the same outer diameter as the first magnet piece, and are radially compared to the first magnet piece. So that the portion located on the axial center side fits into the concave groove. Characterized in that comprising a plurality of second magnet piece disposed in that said first magnet pieces.

  The rotor structure of the permanent magnet type rotating machine according to the second invention is the rotor structure of the first invention, wherein the pair of side surfaces facing each other of the concave groove are inclined along the radial direction, respectively, and the second magnet piece The portion on the axial center side is shaped to fit into the groove.

  A rotor structure of a permanent magnet type rotating machine according to a third invention is the rotor structure according to the first invention, wherein a pair of opposite side surfaces of the concave groove are parallel to each other, and the bottom surface of the concave groove and the The angle formed with the side surface is a right angle, and the portion on the axial center side of the second magnet piece is configured to fit into the concave groove.

  The rotor structure of the permanent magnet type rotating machine according to the fourth invention is the second magnet in the first or third invention, instead of the second magnet piece arranged at a position different from the magnetic pole. A non-magnetic metal material which is formed in the same shape as the piece and has a higher strength than the permanent magnet is used.

  A rotor structure of a permanent magnet type rotating machine according to a fifth invention is the rotor structure of any one of the first to fourth inventions, wherein a pair of corners located on the axial center side of the second magnet piece are formed in an arc shape. It is characterized by that.

  A rotor structure of a permanent magnet type rotating machine according to a sixth invention is the rotor structure of any one of the first to fifth inventions, wherein an inner peripheral surface of the second magnet piece facing the rotation shaft is the rotation shaft. It is formed in the shape of a coaxial arc.

According to the rotor structure of the permanent magnet type rotating machine according to the present invention described above, the radial width of the second magnet piece is formed thicker than the radial width of the first magnet piece. Since the magnet piece is configured to fit into the concave groove of the rotating shaft, the meshing with the rotating shaft can be improved, and the first and the second are independent of the processing dimensional accuracy (gap dimensional accuracy). The second magnet piece can be pressed against the rotating shaft, and there is no difference in the pressing force when filling the adhesive. Moreover, since the rotation torque which acts on a permanent magnet can be transmitted to a rotating shaft by fitting a 2nd magnet piece to the ditch | groove provided in the rotating shaft, the 1st and 2nd magnet piece, Rotational torque can be transmitted even if the adhesive force is reduced after the adhesive is fixed with an adhesive, and can be used even in a high temperature environment.
Furthermore, since the radial width of the first and second magnet pieces, i.e., the wall thickness, is made substantially constant, there is no difference in centrifugal stress between the first and second magnet pieces. can do.

  Further, since the first and second magnet pieces are separated in the circumferential direction, the magnet is an eddy current that is cylindrical and integrally formed, in other words, compared to the case of using an undivided ring magnet. Loss can be reduced, and the tensile stress acting on the axial center side of each of the first and second magnet pieces can be reduced by centrifugal force, so the tightening margin is smaller than when using a ring magnet. It is possible to set the press-fitting temperature low.

  Further, if the angle formed between the bottom of the groove 1b and the side wall is a right angle and the second magnet piece is manufactured in accordance with the shape of the groove, the groove can be easily processed and the cost can be reduced.

  In addition, if a non-magnetic metal material having a higher strength than the permanent magnet is used instead of the second magnet piece arranged at a position different from the magnetic pole, the magnet piece is damaged and the rotational torque cannot be transmitted to the rotating shaft. In addition, even if the permanent magnet is damaged for some reason, the nonmagnetic metal material has great rigidity and is not easily damaged. Therefore, the nonmagnetic metal material can continue to transmit rotational torque to the rotating shaft. Can do.

  In addition, if the corner portion located on the axial center side of the second magnet piece is formed in an arc shape, it is possible to prevent concentration of tensile stress on the corner portion due to centrifugal force accompanying high-speed rotation of the rotor, The configuration is suitable for higher speed rotation.

  Further, if the contact surface between the rotating shaft and the second magnet piece, that is, the bottom surface of the concave groove and the inner peripheral surface of the second magnet piece are formed in an arc shape, the reinforcing ring 4 is provided, thereby providing the axis of the second magnet piece. Concentration of stress generated at corner portions formed by the inner peripheral surface located on the side and the side wall surface that is formed along the radial direction and continues to the inner peripheral surface can be suppressed.

  Embodiments of the present invention will be described in detail in the following examples.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1A is a schematic structural view showing the rotor according to the present embodiment with a part broken away, and FIG. 1B is a cross-sectional view taken along line AA of FIG.

  As shown in FIG. 1, the rotor structure of the permanent magnet type rotating machine in the present embodiment is provided with two or more concave grooves 1a (four in the figure) on the rotary shaft 1, while a substantially cylindrical permanent magnet is used. Four or more first magnet pieces 2 and second magnet pieces 3 that are radially divided from the center in the circumferential direction and have different thicknesses on the outer periphery of the rotating shaft 1 (the figure shows eight permanent magnets). And the reinforcing ring 4 is manufactured by press-fitting, shrink fitting or cold fitting.

  The rotating shaft 1 has a plurality of (four locations in FIG. 1) concave grooves 1a extending along the axial direction on the outer peripheral surface thereof. All the concave grooves 1a are formed in the same shape, and are arranged intermittently and at equal intervals in the circumferential direction. Moreover, as shown in FIG.1 (b), the bottom face which is a surface located in the axial center side of each ditch | groove 1a, and the side surface which is a pair of mutually opposing surface are each planarly formed. Furthermore, each of the pair of side surfaces of the groove 1a has an inclination along the radial direction, so that the circumferential width of the groove 1a becomes wider toward the outer side in the radial direction.

  In addition, the first magnet piece 2 and the second magnet piece 3 (four in this embodiment, respectively) extend in the axial direction and are formed in a substantially arc shape along the outer peripheral surface of the rotating shaft 1. The thicknesses in the radial direction are different from each other, and the second magnet piece 3 is formed thicker than the first magnet piece 2. The first magnet pieces 2 and the second magnet pieces 3 are alternately arranged on the outer peripheral portion of the rotating shaft 1. In other words, the substantially cylindrical permanent magnet arranged on the surface of the rotating shaft 1 is moved in the circumferential direction. It is divided into 8 and the thickness is changed alternately.

  The outer diameter of the first magnet piece 2 and the outer diameter of the second magnet piece 3 are formed to be equal to each other, whereby the first magnet piece 2 and the second magnet piece 3 disposed on the surface of the rotating shaft 1. The outer peripheral surfaces of each of the outer peripheral surfaces are smoothly and continuously formed in the circumferential direction to form a perfect circle in cross section, whereas the inner peripheral surface is formed to be uneven in the circumferential direction. The inner diameter of the first magnet piece 2 is substantially the same as the outer diameter of the rotary shaft 1 and the portion located on the axial center side of the second magnet piece 3 is shaped to fit into the groove 1a. Yes.

  Further, the outer periphery of the first magnet piece 2 and the second magnet piece 3 is provided with a reinforcing ring 4, and the first magnet piece 2 and the second magnet piece 3 are held by the reinforcing ring 4.

  According to the rotor structure of the permanent magnet type rotating machine of the present embodiment, the magnet pieces 2 and 3 of the permanent magnet arranged on the peripheral surface of the rotating shaft are compared with the first magnet piece 2 and the second magnet piece 3. By making the structure thicker, the meshing with the rotating shaft 1 can be improved. Furthermore, since the first magnet piece 2 and the second magnet piece 3 are substantially constant in thickness, and no difference in centrifugal stress occurs between the magnet pieces 2 and 3, damage to the magnet can be suppressed. . In addition, since the first magnet piece 2 and the second magnet piece 3 have a thickness difference, the magnet pieces 2 and 3 can be pressed against the rotary shaft 1 without depending on the machining dimensional accuracy (gap dimensional accuracy) and bonded. There is no difference in the pressing force when filling the agent.

  Further, since the magnet pieces 2 and 3 are separated in the circumferential direction, the magnet eddy current is compared with the case of using a cylindrical and integrally formed permanent magnet, in other words, an undivided ring magnet. Loss can be reduced, and tensile stress acting on the axial center side of the magnet pieces 2 and 3 can be reduced by centrifugal force.

  Further, since the magnet pieces 2 and 3 have a thickness difference and the second magnet piece 3 is configured to fit into the groove 1a of the rotating shaft 1, the permanent magnet and the rotating shaft 1 are engaged with each other. Will improve. Further, since the second magnet piece 3 is fitted in the concave groove 1a provided in the rotating shaft 1, the rotational torque acting on the permanent magnet can be transmitted to the rotating shaft 1, so that the permanent magnet, that is, the magnet pieces 2, 3 And even if the adhesive force is reduced after the rotary shaft 1 is bonded and fixed with an adhesive, the rotational torque can be transmitted, and it can be used even in a high temperature environment.

  Furthermore, since the permanent magnet is separated into the first magnet piece 2 and the second magnet piece 3, the allowance can be reduced compared with the case of using a ring magnet, and the press-fitting temperature can be set low. It becomes possible. Table 1 shows an example in which the press-in temperature of the reinforcing ring in the rotor structure of the permanent magnet type rotating machine of the present embodiment and the press-in temperature of the reinforcing ring in the conventional rotor structure shown in FIG. 7 are calculated.

  The press-fit temperatures shown in Table 1 are such that the peripheral speed of the rotor is 207 m / s, the ambient temperature is 150 ° C., the tensile stress acting on the permanent magnet is 70 MPa, and there is no initial tightening allowance between the permanent magnet and the shaft (if there is a gap, the press-fit temperature Was calculated under the condition that the magnet and the shaft do not separate at a peripheral speed of 207 m / s.

  In the case of the rotor structure of the permanent magnet type rotating machine according to the present embodiment, the thick second magnet piece 3 is not necessarily displaced in the centrifugal direction as compared with the depth of the concave groove 1a of the rotating shaft 1. There is no need to press fit. However, when press-fitting is not performed, a gap is formed between the magnet pieces 2 and 3 and the reinforcing ring 4 at rest. When the rotor is rotated in this state, the reinforcing ring is idled and the magnet pieces 2 and 3 are There is a risk of damage. Therefore, it is preferable to perform press-fitting according to the operating temperature range. The values shown in Table 1 are calculated in consideration of such points.

  As shown in Table 1, in the rotor of the present embodiment, even when the above-mentioned points are taken into consideration, any material of titanium alloy, nickel alloy, stainless steel, and aluminum alloy can be used as the reinforcing ring. At a press-in temperature of about 200 ° C., there was no idling of the reinforcing ring, and torque could be transmitted to the rotating shaft. That is, according to the present embodiment, it is possible to perform low-temperature press-fitting with a significantly reduced press-fitting temperature as compared with a conventional rotor structure using a ring magnet.

  Needless to say, the press-fitting temperature is not limited to 200 ° C., and it is sufficient that the press-fitting can be performed to such an extent that there is no gap between the magnet and the reinforcing ring. Moreover, although the example which uses a nonmagnetic metal as a reinforcement ring was shown in the present Example, the same effect is acquired even if it uses a magnetic body or a high strength fiber etc. as a reinforcement ring.

  A second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view showing the rotor structure of the permanent magnet type rotating machine according to the present embodiment. In this embodiment, the first magnet piece 12 and the second magnet piece 13 shown in FIG. 2 are used in place of the first magnet piece 2 and the second magnet piece 3 in the rotor structure shown in FIG. It is an example. Other configurations are substantially the same as those shown in FIG. 1A and described in the first embodiment. In the following, the same members as those shown in FIG. 1 are denoted by the same reference numerals, and repeated description will be omitted as appropriate.

  As shown in FIG. 2, the rotor structure of the permanent magnet type rotating machine in the present embodiment is provided with two or more concave grooves 1b (four places in FIG. 2) on the rotary shaft 1, while a cylindrical permanent magnet is used. Four or more first magnet pieces 12 and second magnet pieces 13 having a shape divided into eight and having different thicknesses are arranged on the outer peripheral portion of the rotating shaft 1 (eight permanent magnets in the figure), and a reinforcing ring. 4 is manufactured by press fitting, shrink fitting, or cold fitting.

  The rotating shaft 1 has a plurality of (four locations in FIG. 2) concave grooves 1b extending along the axial direction on the outer peripheral surface thereof. All the concave grooves 1b are formed in the same shape and are disposed at regular intervals in the circumferential direction. A pair of side surfaces facing each other of each groove 1b are formed in parallel to each other, and an angle formed by a bottom portion and a side wall of the groove 1b is set to be a right angle. Thereby, the circumferential width of the groove 1b is constant.

  The first magnet piece 12 and the second magnet piece 13 (four in this embodiment) extend in the axial direction and have a substantially arc shape, but have different radial thicknesses. Specifically, the second magnet pieces 13 are formed thicker than the first magnet pieces 12 and are alternately arranged in the circumferential direction. The outer diameter of the first magnet piece 12 is equal to the outer diameter of the second magnet piece 13, so that the first magnet piece 12 and the second magnet piece 13 disposed on the surface of the rotating shaft 1 have their outer peripheral surfaces. Are smoothly continuous in the circumferential direction, whereas the inner circumferential surface is formed to be uneven in the circumferential direction. The inner diameter of the first magnet piece 12 is substantially the same as the outer diameter of the rotary shaft 1, and the portion located on the axial center side of the second magnet piece 13 has a shape that fits into the groove 1b. Yes.

  In Example 1 mentioned above, although the example which has arrange | positioned the magnet pieces 2 and 3 so that it might be in the state which divided | segmented the permanent magnet radially from the axial center of the rotating shaft 1 was shown, as shown in FIG. It is necessary to incline the side wall of the groove 1a of the rotating shaft 1, and it is considered that the processing of the groove 1a is costly.

  On the other hand, according to the present embodiment, as shown in FIG. 2, the angle formed by the bottom of the groove 1b and the side wall is set to a right angle, and the magnet pieces 12 and 13 are manufactured according to the shape of the groove 1b. The processing of the groove 1b is facilitated, and the rotor can be manufactured at a lower cost compared to the first embodiment.

  However, since the permanent magnet is not divided radially from the center, it is considered that compressive stress concentration acts on the corner of the permanent magnet when the permanent magnet and the reinforcing ring are in contact with each other by centrifugal force. Necessary.

  Based on FIG. 3, a third embodiment of the present invention will be described. FIG. 3 is a schematic cross-sectional view showing the rotor structure of the permanent magnet type rotating machine according to the present embodiment.

  As shown in FIG. 3, the present embodiment is different from the first embodiment in that the second magnet piece 3 is located at a position different from the magnetic pole (for example, in the left-right direction in FIG. 1). This is an example in which a high nonmagnetic metal 26 is provided. The nonmagnetic metal 26 is formed in the same shape as the second magnet piece 3. The other configurations are substantially the same as those shown in FIG. 1 and described in the first embodiment, and the same members as those shown in FIG.

  In the first embodiment described above, only the magnet pieces 2 and 3 are arranged as permanent magnets on the rotating shaft 1, but by supporting the magnet pieces 3 with the grooves 1 a provided on the rotating shaft 1, 3 is transmitted to the rotating shaft 1, and if the rotating torque increases, the magnet piece 3 may be damaged and the rotating torque cannot be transmitted to the rotating shaft 1.

  On the other hand, according to the present embodiment, for example, in the case of a two-pole machine, instead of the magnet piece 3 arranged at a position different from the magnetic pole in the first embodiment (left and right direction in FIG. 1), FIG. As described above, by applying a nonmagnetic metal material (for example, stainless steel) having a strength higher than that of the permanent magnet, the magnet piece 3 is damaged and the rotating shaft 1 is applied to the rotating shaft 1 as compared with the rotor structure of the first embodiment. The possibility that torque cannot be transmitted can be greatly reduced. The same applies to the rotor structure of the second embodiment shown in FIG. 2 and described above.

  Furthermore, since the nonmagnetic metal 26 is highly rigid and difficult to break, even if the permanent magnet is broken for some reason, the torque can be continuously transmitted to the rotary shaft 1 by the nonmagnetic metal 26.

However, since the amount of magnets is reduced by applying a non-magnetic metal material instead of a permanent magnet, it is sufficient to select either a permanent magnet or a non-magnetic metal material depending on the required maximum torque value and the number of shaft grooves. It is necessary to consider.

  A fourth embodiment of the present invention will be described with reference to FIG. 4A is a schematic cross-sectional view of the rotor structure of the permanent magnet type rotating machine according to the present embodiment, and FIG. 4B is an enlarged view of a portion B shown in FIG. 4A.

  As shown in FIGS. 4A and 4B, in this embodiment, the second magnet piece 33 shown in FIG. 4 is used instead of the second magnet piece 3 in the first embodiment shown in FIG. It is an example to use. Compared to the second magnet piece 3 described in the first embodiment, the second magnet piece 33 has an inner peripheral surface that is a surface located on the axial center side, and a side wall surface that is a surface formed along the radial direction. Are different in that the corners 33a and 33b are formed in an arc shape in a sectional view. Other configurations are substantially the same as those shown in FIG. 1 and described in the first embodiment, and the same members as those shown in FIG.

  According to the present embodiment described above, the corners 33a and 33b of the second magnet piece 33 are formed in an arc shape in cross section, whereby the corners 33a of the second magnet piece 33 are caused by the centrifugal force accompanying the high-speed rotation of the rotor. , 33b can be prevented from concentrating the tensile stress, so that in addition to the effect of the first embodiment, a configuration suitable for high-speed rotation can be obtained.

  A fifth embodiment of the present invention will be described in detail based on FIG. FIG. 5A is a schematic cross-sectional view of the rotor structure of the permanent magnet type rotating machine according to the present embodiment, and FIG. 5B is an enlarged view of a portion C shown in FIG.

  As shown in FIGS. 5A and 5B, the present embodiment is changed to the concave groove 1a of the rotating shaft 1 and the second magnet piece 3 in the first embodiment shown in FIG. 5 is an example using the concave groove 1c and the second magnet piece 43 shown in FIG.

  The concave groove 1 c has an arc shape in which the bottom surface, which is a surface located on the axial center side, is formed coaxially with the rotary shaft 1 as compared with the concave groove 1 a in the first embodiment. Moreover, the 2nd magnet piece 43 is formed in the circular arc shape like the ditch | groove 1c compared with the 2nd magnet piece 3 in Example 1, and the inner peripheral surface 43a which is a surface located in the axial center side. It is what. Other configurations are substantially the same as those shown in FIG. 1 and described in the first embodiment, and the same members as those shown in FIG.

  According to the above-described embodiment, the contact surface between the rotating shaft 1 and the second magnet piece 43, that is, the bottom surface of the concave groove 1c and the inner peripheral surface located on the axial center side of the second magnet piece 43 are formed in an arc shape. Thereby, it is possible to suppress concentration of stress generated by providing the reinforcing ring 4 to the corner portion formed by the inner peripheral surface of the second magnet piece 43 and the side wall surface formed along the radial direction. .

  Thereby, even if it is a case where a reinforcement ring with a big interference is inserted, compared with the structure of Example 1, concentration of stress can be suppressed and it can prevent that a permanent magnet is damaged by compressive stress. Therefore, it is possible to use a reinforcing ring having a large tightening margin, and a configuration suitable for high-speed rotation can be obtained.

  Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention, for example, by combining a plurality of embodiments. In the above-described embodiment, as shown in FIG. 1A, the end plate 5 has a shape having a large diameter portion and a small diameter portion, and is fitted to a cylindrical reinforcing ring 4 having substantially the same thickness. For example, as shown in FIG. 6, a thin-wall portion is provided at the end of the reinforcing ring 14, and the end plate 15 is formed to have substantially the same thickness and is fitted to the reinforcing ring 14. May be.

  The present invention is suitably applied to a rotor structure of a permanent magnet type synchronous motor and a permanent magnet type rotary generator of a permanent magnet type synchronous generator.

FIG. 1A is a schematic structural diagram of a rotor according to Embodiment 1 of the present invention, and FIG. 1B is a cross-sectional view taken along line AA of FIG. It is sectional drawing of the rotor structure of the permanent magnet type rotary machine which concerns on Example 2 of this invention. It is sectional drawing of the rotor structure of the permanent magnet type rotary machine which concerns on Example 3 of this invention. 4A is a cross-sectional view of a rotor structure of a permanent magnet type rotating machine according to a fourth embodiment of the present invention, and FIG. 4B is a partially enlarged view of FIG. 4A. FIG. 5A is a sectional view of a rotor structure of a permanent magnet type rotating machine according to a fifth embodiment of the present invention, and FIG. 5B is a partially enlarged view of FIG. It is a schematic structure figure which shows the other rotor structure which concerns on the Example of this invention. It is sectional drawing which shows an example of the conventional rotor structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating shaft 1a, 1b, 1c Groove | groove 2,12 1st magnet piece 3,13,23,33,43 2nd magnet piece 4,14 Reinforcement ring 5,15 End plate 26 Nonmagnetic metal material 33a, 33b 2nd Corner part 43a of magnet piece Inner peripheral surface of second magnet piece

Claims (6)

In the rotor structure of a permanent magnet type rotating machine comprising a permanent magnet disposed in a cylindrical shape on the outer peripheral portion of the rotating shaft and a reinforcing member having a cylindrical shape and disposed on the outer peripheral portion of the permanent magnet.
While the rotating shaft has a plurality of concave grooves extending along the axial direction on the surface,
The permanent magnet extends in the axial direction and is formed in an arc shape along the outer peripheral surface of the rotating shaft, and has the same radial width and is disposed between the adjacent grooves on the surface of the rotating shaft. A plurality of first magnet pieces and an outer circumferential surface extending in the axial direction and positioned radially outward are arc-shaped having the same outer diameter as the first magnet pieces, and have a diameter compared to the first magnet pieces. A plurality of second magnet pieces arranged between adjacent first magnet pieces so that a width in the direction is formed thick and a portion located on the axial center side is fitted into the groove. A rotor structure of a permanent magnet type rotating machine. A pair of mutually opposing side surfaces of the concave groove is inclined along the radial direction, and a portion on the axial center side of the second magnet piece is fitted into the concave groove. Item 10. A rotor structure of a permanent magnet type rotating machine according to Item 1. A pair of side surfaces facing each other of the concave groove are parallel to each other, an angle formed by a bottom surface portion of the concave groove and the side surface is a right angle, and an axial center side of the second magnet piece The rotor structure of the permanent magnet type rotating machine according to claim 1, wherein the portion is shaped to fit into the concave groove. Instead of the second magnet piece arranged at a position different from the magnetic pole, a nonmagnetic metal material having the same shape as the second magnet piece and having higher strength than the permanent magnet is used. The rotor structure of the permanent magnet type rotating machine according to any one of claims 1 to 3, wherein the rotor structure is a permanent magnet type rotating machine. The rotation of the permanent magnet type rotating machine according to any one of claims 1 to 4, wherein a pair of corner portions positioned on the axial center side of the second magnet piece are formed in an arc shape. Child structure. 7. The permanent magnet according to claim 1, wherein an inner peripheral surface of the second magnet piece that faces the rotating shaft is formed in an arc shape that is coaxial with the rotating shaft. The rotor structure of a magnet type rotating machine.

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