JP6499033B2 - Rotating electric machine - Google Patents

Description

  Embodiments described herein relate generally to a rotating electrical machine having a salient pole rotor.

  Some rotating electrical machines such as synchronous motors have salient pole rotors. As is well known, the salient pole rotor has a plurality of pole bodies arranged radially on the outer periphery of the rotating shaft. Each of these pole bodies is formed along the axial direction of the rotation shaft, and a coil is wound around each of the pole bodies. A pole head is provided on the upper surface of the pole body in the radial direction. This pole head has a peripheral edge projecting outward from the periphery of the top surface of the pole body. The coil wound around the pole body is suppressed from above, and the coil is poled by centrifugal force during operation. It functions so as not to escape from the body.

  A conductor such as a steel plate is used for this pole head. As is well known, when starting the synchronous motor, an eddy current flows through the pole head in a stopped state due to the rotating magnetic field applied from the stator side. Rotation starts when the magnetic pole generated by the eddy current follows the rotating magnetic field. This eddy current disappears when the rotational speed of the rotor increases and the main pole field and the rotating magnetic field generated by energizing the coil are synchronized.

  That is, the eddy current flows only at the start, but the pole head generates heat due to the eddy current. For this reason, when it takes a long start-up time, the heat generation also increases and the pole head expands thermally. The pole head is firmly fixed to the pole body by bolting or the like, but unbalance occurs due to thermal expansion, causing problems such as vibration during rotation.

  In order to solve such problems, conventionally, the pole head is divided in the length direction, the divided parts are arranged with a space between each other, and the divided parts are connected to each other by a conductor. The eddy current is configured to flow through the entire pole head (see, for example, Patent Document 1).

JP-A-57-193948

  As described above, when the pole head is divided, even if expansion occurs due to heat due to eddy current, the expansion amount is dispersed in a plurality, and the individual expansion amount is reduced. Further, this expansion is absorbed by the space existing between the divided portions, and the pole head can be prevented from becoming unbalanced.

  However, in this configuration, in order to cause an eddy current to flow through the entire pole head, the divided portions must be connected by a conductor. Providing the conductive connection portion on the pole head that rotates at high speed requires a special structure to withstand centrifugal force, and the structure becomes complicated.

  The problem to be solved by the present invention is to provide a rotating electrical machine that can suppress the influence of thermal expansion of the pole head due to eddy currents at the start without complicating the structure of the salient pole rotor.

A rotating electrical machine according to an embodiment of the present invention is a rotating electrical machine having a salient pole rotor and a stator that surrounds the outer periphery of the salient pole rotor with a predetermined interval, and the salient pole rotation The child is a rotating shaft, a plurality of pole bodies radially arranged on the outer periphery of the rotating shaft and formed along the axial direction of the rotating shaft, coils wound around the pole bodies, A pole head provided on an upper surface in the radial direction of the pole body, and the pole head is divided into a plurality of parts in the axial direction of the rotating shaft and is arranged at intervals from each other. portion positioned intermediate the axial direction of the portion is made of a conductive metal material to flow eddy current during startup, the portion positioned at both ends of the axial eddy current at the start is not flow structure using an insulating material such Characterized in that it was.

  According to the above configuration, since the eddy current at the start flows only in a portion located in the middle of the pole head in the axial direction, the structure is simplified, and the thermal expansion of the pole head due to the eddy current at the start is simplified. It is possible to suppress the occurrence of vibration during rotation.

It is sectional drawing of the rotary electric machine which concerns on one Embodiment of this invention. It is a top view of the pole head part of the salient pole type rotor shown in Drawing 1A. It is a perspective view of a salient pole type rotor in one embodiment of the present invention. It is sectional drawing of the rotary electric machine which concerns on other embodiment of this invention. It is sectional drawing of the rotary electric machine which concerns on further another embodiment of this invention. It is sectional drawing of the rotary electric machine which concerns on another embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1A is a cross-sectional view of a rotor and a stator portion of the rotating electrical machine according to this embodiment. In FIG. 1A, the rotating electrical machine 11 includes a salient pole rotor 12 and a cylindrical stator 13 surrounding the outer periphery of the salient pole rotor 12 at a predetermined interval.

  As shown in FIG. 2, the salient pole rotor 12 is radially arranged on the outer periphery of the rotating shaft 15 and the outer periphery of the rotating shaft 15. 4 pole bodies 16. Coils 17 are wound around the pole bodies 16 respectively. A pole head 18 is provided on the upper surface of each pole body 16 in the radial direction. The pole head 18 has a peripheral edge portion 18 a that protrudes outward from the peripheral portion of the upper surface of the pole body 16. The peripheral edge portion 18a is configured so that the coil 17 wound around the pole body 16 is suppressed from above as shown in FIG. 1A so that the coil 17 does not come out of the pole body 16 due to centrifugal force during operation. ing.

  The pole head 18 includes portions 181, 182, and 183 that are divided into a plurality of parts (in the example of the figure, three parts) in the axial direction of the rotating shaft 15. These divided parts 181, 182, and 183 are arranged at intervals from each other as shown in FIG. 1A. Of the plurality of portions 181, 182 and 183, a portion located in the middle in the axial direction (hereinafter referred to as an axial middle portion) 182 is configured such that an eddy current at the start flows. On the other hand, the portions (hereinafter referred to as axial end portions) 181 and 183 located at both ends in the axial direction have a structure in which almost no eddy current flows at the start. For example, the axial intermediate portion 182 of the pole head 18 is made of a conductive metal material, and the axially opposite end portions 181 and 183 use a high resistance material including an insulating material (in the example of FIG. 1A, an insulating material is used. ).

  Here, the length of the intermediate portion 182 in the axial direction of the pole head 18 is formed longer than both end portions 181 and 183 as shown in the figure. That is, the minimum length required for starting by the eddy current described above is used. Further, the respective parts 181, 182, and 183 of the pole head 18 are integrally fixed on the pole body 16 by a plurality of bolts 19 as shown in FIG. Is provided close to the central portion in the length direction. This is because the end portion of the axial intermediate portion 182 is free from the elongation in the length direction of the axial intermediate portion 182 due to heat generation, and the shape of the axial intermediate portion 182 can be changed by heat.

  In the above configuration, when the rotating electrical machine 11 is started, a rotating magnetic field is applied from the stator 13, so that an eddy current is generated on the surface of the intermediate portion 182 in the axial direction of the pole head 18 of the salient pole rotor 12. The salient pole rotor 12 starts to rotate as the magnetic pole generated by the eddy current follows the rotating magnetic field. Then, the rotational speed of the salient pole rotor 12 increases, the main pole field and the rotating magnetic field generated by energization of the coil 17 are synchronized, and the salient pole rotor 12 rotates at the synchronous speed. Disappear.

  Here, in the case of the conventional integrated pole head, it was confirmed that a large amount of eddy current at the start flowed in the central portion in the longitudinal direction of the pole head and did not flow so much at both ends in the longitudinal direction. Therefore, in the embodiment of the present invention, as described above, the pole head 18 is divided into three in the axial direction of the rotary shaft 15, and an eddy current is caused to flow only in the intermediate portion 182 in the axial direction. That is, an insulating material is used for both end portions 181 and 183 in the axial direction of the pole head 18 so that no eddy current flows in both end portions 181 and 183 in the axial direction of the pole head 18.

  For this reason, heat generation due to eddy current at the time of start occurs only in the axial intermediate portion 182 of the pole head 18 and does not occur in both end portions 181 and 183. The axial intermediate portion 182 is thermally expanded due to heat generation, but the amount of thermal expansion is small because the original length is shorter than that of an integral pole head, and it can be sufficiently absorbed by the distance between the end portions 181 and 183. . Further, since the fixing portion of the axial intermediate portion 182 by the bolt 19 is brought close to the center in the length direction, the end portion in the length direction can be thermally expanded relatively easily. For these reasons, large thermal distortion does not occur, and the salient pole rotor 12 does not become unbalanced during rotation and does not generate vibration.

  Here, the three divided parts 181, 182 and 183 of the pole head 18 are firmly fixed on the pole body 16 by a plurality of bolts 19 as shown in FIG. 1B. Of these, the axial intermediate portion 182 is free of both ends when the axial intermediate portion 182 is thermally expanded by firmly fixing only the axial central portion with a bolt or the like as described above. , It can be easily thermally expanded in the length direction.

  However, in the case of a high-speed rotating model, both end portions of the axial intermediate portion 182 may be rolled up by centrifugal force during rotation. Therefore, as shown in FIG. 3, both end portions of the axial intermediate portion 182 of the pole head 18 are engaged with both axial end portions 181 and 183 of the pole head 18. Since the axial end portions 181 and 183 are firmly fixed to the pole body 16 with a plurality of bolts 19, both end portions of the axial intermediate portion 182 are displaced radially (upward in the figure) by the above-described engagement configuration. Lock to do. Therefore, it is possible to reliably prevent the both end portions of the axial intermediate portion 182 from rolling up due to the centrifugal force during rotation.

  In the above embodiment, both end portions 181 and 183 in the axial direction of the pole head 18 are made of an insulating material, but a metal material similar to that in the intermediate portion 182 in the axial direction may be used. That is, as described above, even in the conventional one-piece pole head, the eddy current at the time of starting does not flow so much at both end portions in the axial direction, but in the present invention, the axial intermediate portion 182 and both end portions 181 thereof. , 183, the eddy current at the start hardly flows through the both end portions 181 and 183 even if it is a metal material.

  Further, as shown in FIG. 4, the opposing distance g2 between the axially opposite end portions 181 and 183 of the pole head 18 and the inner periphery of the stator 13 is opposed to the inner periphery of the stator 13 of the axially intermediate portion 182. By setting it larger than the gap g1, it is possible to more reliably prevent the eddy current from flowing at the start even if the axial end portions 181 and 183 are metal members.

  FIG. 5 similarly shows a case where both end portions 181 and 183 in the axial direction of the pole head 18 are metal members. Here, as described above, the axial intermediate portion 182 of the pole head 18 is configured such that only the central portion in the axial direction is firmly fixed with a bolt or the like and both ends are free to be easily thermally expanded. Both end portions in the axial direction of the portion 182 are engaged with the adjacent both end portions 181 and 183 in the axial direction, and both end portions due to centrifugal force during rotation are prevented from rolling up.

  Also in this case, since both end portions 181 and 183 in the axial direction of the pole head 18 are metal members, as shown in FIG. 5, the distance g2 facing the inner periphery of the stator 13 is fixed to the intermediate portion 182 in the axial direction. It is set to be larger than the distance g1 facing the inner circumference of the child 13.

  By configuring in this way, it is possible to more reliably prevent an eddy current at the start from flowing even when the axial end portions 181 and 183 are metal members. Moreover, it can prevent reliably that the both ends of the axial direction intermediate part 182 are rolled up by the centrifugal force at the time of rotation.

  Although several embodiments of the present invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 11 ... Rotating electrical machine 12 ... Salient pole type rotor 13 ... Stator 15 ... Rotating shaft 16 ... Pole body 17 ... Coil 18 ... Pole head 181, 182, 183 ... Divided part of pole head

Claims (2)

A rotating electric machine having a salient pole rotor and a stator surrounding the outer circumference of the salient pole rotor with a predetermined interval,
The salient pole rotor includes a rotating shaft, a plurality of pole bodies radially arranged on the outer periphery of the rotating shaft and formed along the axial direction of the rotating shaft, and wound around the pole bodies, respectively. And a pole head provided on the radial upper surface of the pole body,
The pole head is divided into a plurality of parts in the axial direction of the rotary shaft and is arranged at intervals from each other, and a part located in the middle of the axial direction among these parts is an eddy current at the time of starting. composed of a conductive metal material to flow, the rotating electrical machine portion positioned at both ends of the axial direction, characterized in that it has a structure using an insulating material such eddy current at the start is not flow. Both end portions in the axial direction of the portion of the pole head positioned at the intermediate portion in the axial direction are configured to engage with the portions positioned at both ends in the axial direction , and the displacement in the radial direction is locked. The rotating electrical machine according to claim 1.

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