JP6159979B2 - Rotor structure of rotating electrical machine - Google Patents

Description

  The present invention relates to a rotor structure of a rotating electrical machine that eliminates a local high-temperature region in a heated field winding.

  2. Description of the Related Art Conventionally, there has been provided a rotating electrical machine including a salient pole type rotor having a plurality of magnetic poles on an outer peripheral portion. In such salient-pole rotors, a plurality of magnetic cores protruding outward in the radial direction are arranged at equal intervals in the circumferential direction, and field windings are arranged on the outer periphery of these magnetic cores. It is wound through an insulating plate.

  And as a rotor structure of the conventional rotary electric machine as mentioned above, it is indicated by patent documents 1, for example.

Japanese Patent Laid-Open No. 7-231592

  Here, in order to rotate the salient pole type rotor with respect to the stationary side stator, it is necessary to pass an exciting current through the field winding to generate a magnetic field inside the field winding. . Thus, when an exciting current is passed through the field winding, the field winding generates heat due to the flow of the current. On the other hand, the heated field winding is cooled by heat radiation from the outer peripheral surface by cooling air or the like, or by heat transfer to the magnetic pole core.

  However, as described above, since an insulating plate is interposed between the magnetic core and the field winding, heat transfer from the generated field winding to the magnetic core is not efficiently performed. There is a case. As a result, there is a possibility that a local high-temperature portion may occur in the field winding, and such a local high-temperature portion in the field winding becomes a factor that hinders the reduction in size and weight of the machine. ing.

  Therefore, the present invention solves the above-described problem, and efficiently reduces the temperature and weight of the machine by efficiently transferring heat from the field winding and suppressing the temperature rise of the generated field winding. An object of the present invention is to provide a rotor structure of a rotating electrical machine that can be realized.

The rotor structure of the rotating electrical machine according to the first invention for solving the above-described problem is
A plurality of magnetic cores that protrude radially outward from the outer periphery of the rotating shaft and are arranged at equal intervals in the circumferential direction;
A field winding wound around the outer periphery of the magnetic core;
A plurality of insulating plates interposed between the outer peripheral surface of the magnetic core and the inner peripheral surface of the field winding;
The field winding is
An upstream side formed on the upstream side in the rotational direction;
A downstream side portion formed on the downstream side in the rotation direction,
Of the insulating plate in contact with the highest temperature portion in the upstream side portion and the insulating plate in contact with the highest temperature portion in the downstream side portion, at least in the upstream side portion The insulating plate that is in contact with the highest temperature portion has the highest thermal conductivity among all the insulating plates, and is a highly thermally conductive insulating plate having a lower strength than the remaining insulating plates ,
Moreover, it is provided between the field windings adjacent to each other in the circumferential direction, and is arranged on the outer peripheral surface of the downstream side portion of the field winding arranged on the upstream side in the rotational direction and on the downstream side in the rotational direction. A pressing member for pressing the outer peripheral surface of the upstream side portion of the field winding from the outer circumferential side;
The pressing position at which the pressing member presses the outer peripheral surface is a position that does not face the high thermal conductivity insulating plate in the radial direction .

The rotor structure of the rotating electrical machine according to the second invention for solving the above-described problem is
The high thermal conductivity insulating plate is
It is characterized by being interposed in contact with the central portion in the rotational axis direction of the upstream side portion and the central portion in the rotational axis direction of the downstream side portion.

The rotor structure of the rotating electrical machine according to the third invention for solving the above-described problem is
The high thermal conductivity insulating plate is
It contains at least one material selected from aluminum nitride, aluminum oxide, silicon nitride, and boron nitride.

  Therefore, according to the rotor structure of the rotating electrical machine according to the present invention, the insulating plates that are in contact with the highest temperature portions in the upstream side portion and the downstream side portion of the field winding are arranged in all the insulating plates. By using a high thermal conductivity insulating plate having the highest thermal conductivity, heat transfer from a local high temperature region in the field winding to the magnetic core can be performed efficiently. Thereby, the temperature rise of the field winding generated by the exciting current can be suppressed, and the size and weight of the machine can be reduced as much as the cooling performance for the field winding is improved.

It is a longitudinal cross-sectional view in the rotor structure of the rotary electric machine which concerns on one Example of this invention. It is II-II arrow sectional drawing of FIG. It is an external appearance perspective view of a salient pole rotor. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3. It is a disassembled perspective view in the magnetic pole of a salient pole type rotor.

  Hereinafter, a rotor structure of a rotating electrical machine according to the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, the rotating electrical machine 1 includes a stationary stator 2 and a rotating salient pole rotor 3.

  The stator 2 has a cylindrical shape and is formed by stacking a plurality of magnetic steel plates (laminated steel plates) in the axial direction. On the other hand, the salient pole rotor 3 is disposed coaxially with the stator 2 on the radially inner side of the stator 2 and is supported rotatably with respect to a housing (not shown). .

  Here, as shown in FIGS. 1 to 4, the salient pole rotor 3 includes a rotating shaft portion 11, a fan 12, a rotor yoke 13, a magnetic pole core 14, a magnetic pole head 15, a field winding 17, And it is comprised from the coil pressing member 18 grade | etc.,.

  The rotating shaft portion 11 serves as the center of rotation of the salient pole rotor 3, and both axial end portions thereof are rotatably supported by the housing via bearings (not shown). And the fan 12 is coaxially fixed to the axial direction both ends of the axial direction inner side rather than the bearing in the rotating shaft part 11. As shown in FIG. That is, the fan 12 rotates together with the rotation shaft portion 11 when the rotation shaft portion 11 rotates.

  Further, a rotor yoke 13 is integrally formed at the axial center of the rotating shaft portion 11 so as to extend along the axial direction of the rotating shaft portion 11. Further, a plurality of magnetic pole cores 14 are formed on the outer peripheral portion of the rotor yoke 13, and these magnetic pole cores 14 protrude radially outward from the outer peripheral portion of the rotor yoke 13, It arrange | positions at equal intervals in the circumferential direction.

  As described above, the rotating shaft 11, the rotor yoke 13, and the magnetic pole core 14 are integrally formed, and are formed by cutting out from a massive magnetic material.

  A field winding (coil) 17 is wound around the outer periphery of the magnetic pole core 14. As a result, the field winding 17 has a frame shape and a rectangular shape in a plan view as viewed from the radial direction, and is formed on one end side of the rotation axis direction (hereinafter, referred to as a side of the rotation axis direction). 17a, the other end side in the rotation axis direction (hereinafter referred to as the other end side portion) 17b formed on the other end side in the rotation axis direction, and the rotation direction formed on the upstream side in the rotation direction. An upstream side portion (hereinafter referred to as upstream side portion) 17c and a rotational direction downstream side portion (hereinafter referred to as downstream side portion) 17d formed on the downstream side in the rotational direction are configured. .

  On the other hand, a magnetic pole head 15 is fixed to a radially outer end face (top face) of the magnetic core 14 by a plurality of bolts 16. The radially outer end surface (top surface) of the magnetic pole head 15 has an arc shape along the inner peripheral surface of the stator 2, and the radial direction is between the inner peripheral surface of the stator 2. Has a predetermined amount of gap.

  At this time, the magnetic pole head 15 is provided so as to cover the field winding 17 from the outside in the radial direction, so that the field winding 17 is formed on both sides in the radial direction by the rotor yoke 13 and the magnetic pole head 15. It is in a state of being pinched. Thereby, even if the centrifugal force generated with the rotation of the salient pole rotor 3 acts on the field winding 17, the field winding 17 is directed radially inward by the magnetic pole head 15. Since it is pressed down, deviation of the field winding 17 from the magnetic core 14 can be prevented.

  In addition, as shown in FIGS. 1, 2, 4 and 5, a plurality of insulating plates 31 and insulating plates (high thermal conductive insulation) are provided between the outer peripheral surface of the magnetic core 14 and the inner peripheral surface of the field winding 17. Plate) 32 is interposed one by one along the circumferential direction of the outer circumferential surface and the circumferential direction of the inner circumferential surface.

  Two insulating plates 31 are interposed between the magnetic core 14 and the one end side portion 17a. Similarly, two insulating plates 31 are interposed between the magnetic pole core 14 and the other end side portion 17b.

  On the other hand, two insulating plates 31 and one insulating plate 32 are interposed between the magnetic pole core 14 and the upstream side portion 17c. Similarly, two insulating plates 31 and one insulating plate 32 are interposed between the magnetic pole core 14 and the downstream side portion 17d.

  This will be described in detail. The insulating plates 31 are in contact with both sides of the upstream side portion 17c in the rotational axis direction, and the insulating plates 32 are opposed to the central portion of the upstream side portion 17c in the rotational axis direction. It touches. The insulating plate 31 is in contact with both sides of the downstream side portion 17d in the rotation axis direction, and the insulating plate 32 is in contact with the central portion of the downstream side portion 17d in the rotation axis direction.

  Here, the insulating plates 31 and 32 are formed using, for example, an epoxy resin, and the thermal conductivity of the insulating plate 32 is higher than the thermal conductivity of the insulating plate 31. Thus, in order to improve the thermal conductivity of the insulating plate 32 over the thermal conductivity of the insulating plate 31, the aluminum resin, the aluminum oxide, the silicon nitride, the epoxy resin for forming the insulating plate 32, It is possible by adding at least one additive among high thermal conductivity additives (fillers) such as boron nitride.

  However, if the high thermal conductivity additive described above is included in the material, the strength of the material is lowered, so that the strength of the insulating plate 32 is lower than the strength of the insulating plate 31. That is, the insulating plate 32 is an insulating plate having a thermal conductivity higher than that of the insulating plate 31 and a strength lower than that of the insulating plate 31.

  As described above, by providing the insulating plate 32 having a thermal conductivity higher than that of the insulating plate 31, the portion of the field winding 17 that is in contact with the insulating plate 32 is insulated in the field winding 17. The thermal conductivity to the magnetic pole core 14 is improved as compared with the portion in contact with the plate 31.

  Further, as shown in FIGS. 2 to 4, a plurality of coil pressing members 18 are provided side by side in the rotational axis direction between the field windings 17 adjacent in the circumferential direction. These coil pressing members 18 have a wedge shape and are fixed to the rotor yoke 13 by bolts 19.

  That is, the coil pressing member 18 includes the outer peripheral surface of the downstream side portion 17d of the field winding 17 disposed on the upstream side in the rotation direction, and the downstream side in the rotation direction, of the two field windings 17 adjacent in the circumferential direction. The bolts 19 are fastened and fixed from the radially outer side to the radially inner side in contact with the outer peripheral surface of the upstream side portion 17c of the field winding 17 arranged on the side.

  As described above, when the wedge-shaped coil pressing member 18 is fixed by the bolt 19, the tightening force of the bolt 19 acts on the coil pressing member 18, and then each field winding disposed on both sides in the width direction of the coil pressing member 18. It acts as a pressing force on the line 17. That is, the outer peripheral surface of the downstream side portion 17d in the field winding 17 disposed on the upstream side in the rotational direction and the outer peripheral surface of the upstream side portion 17c in the field winding 17 disposed on the downstream side in the rotational direction. These are pressed from the outside in the circumferential direction.

  Thereby, even if the centrifugal force generated with the rotation of the salient pole rotor 3 acts on the field winding 17, the outer peripheral surface and the downstream side of the upstream side portion 17 c in the field winding 17. Since the outer peripheral surface of the portion 17d is pressed by the coil pressing member 18, the field winding 17 can be prevented from being deformed (winding deviation) due to the component force of the centrifugal force.

  At this time, the pressing position where the coil pressing member 18 presses the outer peripheral surface of the downstream side portion 17d arranged on the upstream side in the rotation direction and the outer peripheral surface of the upstream side portion 17c arranged on the downstream side in the rotation direction is The insulating plate 32 is not opposed to the insulating plate 32 in the radial direction, and is opposed to the insulating plate 31 in the radial direction.

Thus, the pressing position of the coil holding member 18, instead of the position Oite facing the insulating plate 32 and radially, by a position facing the insulating plate 31 and the radial direction by the pressing force Damage to the insulating plate 32 is prevented. That is, as described above, as the thermal conductivity of the insulating plate 32 is improved, the strength of the insulating plate 31 is lower than that of the insulating plate 31. The insulating plate 32 is protected by providing the coil pressing member 18 so as to face the insulating plate 31 having higher strength.

  Further, a space extending in the rotation axis direction is formed between the field windings 17 adjacent in the circumferential direction by using the magnetic core 14 as a protruding portion. Such a space extending in the direction of the rotation axis serves as a ventilation path 20 for flowing the cooling air F in the direction of the rotation axis, and the cooling air F is rotated by the fan 12 together with the rotation shaft 11. Caused by. That is, since the fans 12 are provided at both ends in the axial direction of the rotary shaft portion 11, the cooling air F generated by the rotation of the fan 12 passes through the ventilation path 20 from both sides in the rotary shaft direction to the center in the rotary shaft direction. It flows toward the part.

  Thereby, the cooling air F collides with the outer peripheral surface of the one end side part 17a and the outer peripheral surface of the other end side part 17b in the field winding 17, or enters the ventilation path 20 and both sides of the entering direction. In contact with the outer peripheral surface of the upstream side portion 17c and the outer peripheral surface of the downstream side portion 17d located at the portion (both sides in the flow direction). As a result, the field winding 17 generates heat when an exciting current is applied, but the temperature rise is suppressed by the heat radiation from each outer peripheral surface by the cooling air F.

  However, the central portion in the rotation axis direction of the upstream side portion 17c and the downstream side portion 17d constituting the ventilation path 20 is located on the most downstream side in the flow direction of the cooling air F, and the rotation direction of the rotation axis is determined by the coil pressing member 18. It is sandwiched from both sides. As a result, the cooling air F hardly reaches the central portion in the rotational axis direction of the upstream side portion 17c and the central portion in the rotational axis direction of the downstream side portion 17d. Accordingly, since the cooling effect on the central portion in the rotation axis direction is lower than the cooling effect on other portions, the temperature at the central portion in the rotation axis direction tends to be higher than the temperature at other portions.

  Further, when the salient pole rotor 3 is rotated, the counter wind is received from the direction opposite to the rotation direction. Among the field windings 17, the upstream side in the rotation direction is also received. Comparing the part and the downstream part in the rotational direction, the counter wind is in contact with the downstream part in the rotational direction, while the counter wind is hardly in contact with the upstream part in the rotational direction. . Thereby, the site | part of the rotation direction upstream is harder to cool than the site | part of the rotation direction downstream, and exists in the tendency for temperature to become high.

  That is, among the upstream side portion 17c and the downstream side portion 17d, the temperature in the central portion in the rotation axis direction is higher than that in the both sides in the rotation axis direction. Further, comparing the central portion in the rotational axis direction of the upstream side portion 17c with the central portion in the rotational direction of the downstream side portion 17d, the central portion in the rotational axis direction of the upstream side portion 17c is the downstream side portion 17d. The temperature becomes higher than the central portion in the rotation axis direction.

  The temperature distribution in the field winding 17 that has generated heat is represented by the density of dots as shown in FIGS. That is, as the dot density increases, the temperature increases.

  Therefore, in the rotor structure according to the present invention, in order to improve the thermal conductivity with respect to the central portion in the rotational axis direction of the upstream side portion 17c and the downstream side portion 17d that become high temperature, An insulating plate 32 made of a material having high thermal conductivity is provided only between the central portion and the magnetic pole core 14. That is, the temperature of the field winding 17 is improved by efficiently conducting heat conduction from the central portion in the rotational axis direction of the upstream side portion 17c and the central portion in the rotational axis direction of the downstream side portion 17d to the magnetic core 14. Suppress the overall increase.

  However, depending on the temperature at the central portion in the rotational axis direction of the downstream side portion 17d, the insulating plate 31 that contacts the central portion in the rotational axis direction is the insulating plate 31, and the central portion in the rotational axis direction of the upstream side portion 17c. Only the insulating plate in contact with the insulating plate 32 may be used as the insulating plate 32.

  Further, in the case where a double-sided suction structure in which the fan 12 is provided at both axial ends of the rotating shaft portion 11 as in the above-described embodiment, the upstream side of the single field winding 17 is used. The central portion in the rotational axis direction of the side portion 17c and the central portion in the rotational axis direction of the downstream side portion 17d are the most downstream portions through which the cooling air F flows and are relatively high in temperature. Only the insulating plate that comes into contact is the insulating plate 32.

  On the other hand, in the case of adopting the one-side suction structure in which the fan 12 is provided at one end in the axial direction among the one end and the other end in the axial direction of the rotating shaft 11, one field winding is used. Among the lines 17, the rotation side in the upstream side 17 c and the side 17 d on the downstream side away from the fan 12 in the direction of the rotation axis (the side in the direction of the rotation axis opposite to the side in the direction of the rotation axis facing the fan 12). However, since it becomes the most downstream part through which the cooling air flows and becomes relatively high in temperature, only the insulating plate that contacts the side portion in the rotation axis direction may be the insulating plate 32.

  In other words, the insulating plate 32 may be the insulating plate that contacts the part having the highest temperature in the upstream side portion 17c and the downstream side portion 17d.

  As described above, a magnetic field can be generated inside the field winding 17 by passing an exciting current through the field winding 17. Then, by utilizing the repulsive force and the attractive force between the magnetic field (rotating magnetic field) generated on the stator 2 side and the magnetic field generated on the salient pole rotor 3 side, salient pole rotation The child 3 can be rotated with respect to the stator 2. At this time, the field winding 17 generates heat by passing an exciting current.

  At the same time, as the rotating shaft 11 rotates, the fan 12 rotates, so that the cooling air F generated by the rotation of the fan 12 is directed toward one end side and the other end side of the ventilation path 20 in the rotating shaft direction. After being supplied, the air enters from one end side and the other end side in the rotation axis direction, and flows toward the center portion in the rotation axis direction of the ventilation path 20.

  Thereby, the cooling air F collides with the outer peripheral surface of the one end side portion 17 a and the outer peripheral surface of the other end side portion 17 b in the field winding 17, or the outer periphery of the upstream side portion 17 c in the field winding 17. Or the outer peripheral surface of the surface and the downstream side portion 17d. As a result, the heat generated in the field windings 17 is released from the outer peripheral surface thereof.

  At this time, due to the suction on both sides by the two fans 12 and the installation of the two coil pressing members 18 in the ventilation path 20, the central portion in the rotational axis direction of the upstream side portion 17c and the central portion in the rotational axis direction of the downstream side portion 17d. The part may become hot.

  However, since the insulating plate 32 is interposed so as to be in contact with those local high temperature portions, the magnetic poles are formed from the central portion in the rotational axis direction of the upstream side portion 17c and the central portion in the rotational axis direction of the downstream side portion 17d. Heat transfer to the iron core 14 is performed efficiently. Thereby, the temperature rise of the field winding 17 is suppressed as a whole.

  In the insulating plate 31, heat is transferred from the field winding 17 to the magnetic pole core 14, and heat is also radiated from the outer peripheral surface of the insulating plate 31 due to the collision of the counter wind against the field winding 17.

  Therefore, according to the rotor structure of the present invention, by providing the insulating plate 32 having a high thermal conductivity in contact with the high temperature portion of the field winding 17 that is locally high in temperature, Since heat transfer from the high temperature portion to the magnetic pole core 14 can be performed efficiently, the temperature rise of the field winding 17 generated by the exciting current can be suppressed as a whole. Therefore, the diameter of the salient pole rotor 3 can be reduced by the amount that the cooling performance for the field winding 17 is improved, so that the rotating electrical machine 1 can be reduced in size and weight.

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 2 Stator 3 Salient pole rotor 11 Rotating shaft part 12 Fan 13 Rotor yoke 14 Magnetic pole core 15 Magnetic pole head 16 Bolt 17 Field winding 17a Rotating shaft direction one side part 17b Rotating shaft direction etc End side portion 17c Rotating direction upstream side portion 17d Rotating direction downstream side portion 18 Coil pressing member 19 Bolt 20 Ventilation path 31, 32 Insulating plate F Cooling air

Claims (3)

A plurality of magnetic cores that protrude radially outward from the outer periphery of the rotating shaft and are arranged at equal intervals in the circumferential direction;
A field winding wound around the outer periphery of the magnetic core;
A plurality of insulating plates interposed between the outer peripheral surface of the magnetic core and the inner peripheral surface of the field winding;
The field winding is
An upstream side formed on the upstream side in the rotational direction;
A downstream side portion formed on the downstream side in the rotation direction,
Of the insulating plate in contact with the highest temperature portion in the upstream side portion and the insulating plate in contact with the highest temperature portion in the downstream side portion, at least in the upstream side portion The insulating plate that is in contact with the highest temperature portion has the highest thermal conductivity among all the insulating plates, and is a highly thermally conductive insulating plate having a lower strength than the remaining insulating plates ,
Moreover, it is provided between the field windings adjacent to each other in the circumferential direction, and is arranged on the outer peripheral surface of the downstream side portion of the field winding arranged on the upstream side in the rotational direction and on the downstream side in the rotational direction. A pressing member for pressing the outer peripheral surface of the upstream side portion of the field winding from the outer circumferential side;
The rotating structure of the rotating electrical machine according to claim 1 , wherein a pressing position where the pressing member presses the outer peripheral surface is a position that does not face the high thermal conductive insulating plate in a radial direction . The rotor structure of the rotating electrical machine according to claim 1 ,
The high thermal conductivity insulating plate is
A rotor structure of a rotating electrical machine, wherein the rotor side structure is interposed between and in contact with the central portion in the rotational axis direction of the upstream side portion and the central portion in the rotational axis direction of the downstream side portion. In the rotor structure of the rotating electrical machine according to claim 1 or 2 ,
The high thermal conductivity insulating plate is
A rotor structure for a rotating electrical machine, comprising at least one material selected from aluminum nitride, aluminum oxide, silicon nitride, and boron nitride.

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