JP2022178206A - Rotary electric machine - Google Patents

Abstract

To make it possible to hold a magnetic field winding on a salient pole part against centrifugal force during rotation while making a slot area as large as possible, according to a rotary electric machine of a format of being wound around a salient pole of a rotor with the magnetic field winding.SOLUTION: A rotor 5 comprises a plurality of salient poles 6 protruding in a radial direction thereof along a circumferential direction thereof. According to a rotary electric machine 1 whose magnetic field winding 7 is wound around each of the salient poles along a direction perpendicular to a radial direction of the rotor, an annular member 8 enclosing an outer peripheral surface of part 7a protruding from each of the salient poles along the circumferential direction of the rotor is provided in a rotating axial line direction of the rotor of the magnetic field winding. It is limited by the annular member to move in the radial direction of the rotor of the magnetic field winding.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a rotating electric machine, and more particularly, to the structure of a rotor of a rotating electric machine around which a field winding is wound.

In a rotating electric machine (synchronous machine) in which the armature winding is wound around the stator and the field winding is wound around the rotor, the field winding is subjected to centrifugal force during rotation of the rotor. Therefore, structure is required to hold the field windings on the rotor. For example, in Patent Document 1, a field-winding type synchronous machine including a stator with an armature winding and a rotor with a field winding is provided with a plurality of rotor windings. Magnetic salient pole portions are formed integrally with the rotor core and project from the outer peripheral surface of the rotor core in the radial direction of rotation. Rotation from between the magnetic salient poles by a holding member whose one end is supported by the projecting ends of the magnetic salient poles and whose other end is supported by a support formed between the plurality of magnetic salient poles in the rotor core Arrangements have been proposed in which they are held against movement radially outward.

JP 2008-178211

By the way, in the structure of the rotor in which the field winding is wound around the salient pole portions as described above, the slot area between the adjacent salient pole portions (the space (slot) between the adjacent salient pole portions) , the cross-sectional area perpendicular to the axis of rotation of the rotor), the larger the area devoted to the field winding, the larger the area where the field current can flow, Since resistance is reduced, loss can be suppressed. On the other hand, as described above, it is necessary for the rotor to be able to hold the field windings on the salient pole portions against the centrifugal force during rotation. If the outer peripheral edge of the rotor contacting the field winding is widened or thickened, the area occupied by the salient poles in the cross section of the rotor becomes large, and the slot area is reduced accordingly. It will happen. Similarly, when a holding member for holding the winding is inserted into the slot as in Patent Document 1, the slot area is similarly reduced by the area occupied by the holding member. Therefore, in the rotor in which the field windings are wound around the salient pole portions, there is a configuration in which the field windings can be held against the centrifugal force during rotation while making the slot area as large as possible. and advantageous.

Thus, one object of the present invention is to increase the slot area as much as possible in a rotary electric machine in which field windings are wound around the salient poles of a rotor, while reducing centrifugal force during rotation. It is an object of the present invention to provide a structure that allows the field winding to be held on the salient poles against the field windings.

According to the present invention, the above problem is solved by the rotor having a plurality of salient poles protruding radially along the circumferential direction thereof, and each of the salient poles extending radially of the rotor. A rotating electric machine in which a field winding is wound along a vertical direction, and the portion of each of the field windings protruding from each of the salient pole portions in the rotation axis direction of the rotor An annular member is provided to surround the radial outer peripheral surface along the circumferential direction of the rotor, and the annular member restricts movement of the field winding in the radial direction of the rotor. achieved.

In the configuration of the apparatus described above, the "rotating electric machine" may be a synchronous machine in which a field winding is wound around a rotor. Typically, 2, 4, 6, 8, etc. salient pole portions may be provided in the circumferential direction of the rotor. The field windings may be wound in a conventional manner circumferentially around the side of each salient pole, with the center axis pointing radially of the rotor, as described above, and the outer side of the salient pole. The peripheral edge protrudes and extends in the circumferential direction of the rotor, and may be formed so as to surround at least a portion of the field winding in the space between the adjacent salient pole portions (rotation axis of the rotor In the cross section of the salient pole portion in the plane direction perpendicular to , the outer peripheral edge of the salient pole portion may be formed to have a wide umbrella shape.). Further, in the rotor of the rotating electrical machine, the portion of the field winding wound around each salient pole portion protruding from each salient pole portion in the rotation axis direction of the rotor (rotor is surrounded by an annular member extending along the circumferential direction of the rotor, the annular member being configured to limit rotor radial movement of the field windings.

As described above, the portion of the field winding protruding from each of the salient pole portions in the rotation axis direction of the rotor, that is, the portion of each salient pole portion protruding from the end of the rotor in the rotation axis direction is By being surrounded by the annular member, even when the field winding is subjected to centrifugal force acting on each salient pole portion in the radial direction of the rotor when the rotor rotates, As a result, forces act in opposing directions from the field windings arranged over the entire circumference of the rotor, so that they cancel each other out. Radial movement of the rotor will be blocked, and a structure will be provided in which each field winding is retained on each salient pole. At this time, the annular member is arranged outside the end of each salient pole in the rotation axis direction of the rotor. can be taken as large as possible, thus reducing the losses in the field winding current, as described above. Further, since the annular member can hold the field winding without entering the slot, it is also possible to shorten the extending length of the umbrella-shaped portion at the outer peripheral end of the salient pole portion or to reduce the thickness thereof. Since it becomes possible, it becomes possible to further increase the slot area.

In the above configuration, the annular member may be made of non-magnetic material having any appropriate strength, such as carbon fiber material or resin material. Its shape may be toric, polygonal toroidal, or a combination thereof, and the width and thickness may be set according to the fit. In addition, the annular member may be provided at one end or both ends of the rotor in the rotation axis direction (the annular member is preferably provided at both ends because the field winding can be held more reliably, but It may be just the edge, and such a case is also within the scope of the present invention.).

Furthermore, in the above configuration, the position of the field windings in the radial direction of the rotor is restricted by the annular member, so that the radially outer surface of the rotor of the field windings is the outer circumference of the salient poles. It may be spaced from the inner surface of the umbrella portion at the end. In this case, the pressing force from the field winding due to the centrifugal force does not act on the umbrella-shaped portion at the outer peripheral end of the salient pole portion, and it is possible to reduce the rigidity required for the outer peripheral end of the salient pole portion. It is possible to reduce the weight of the rotor and further increase the slot area.

Thus, according to the structure of the rotary electric machine according to the present invention, the annular member is adapted to hold the position of the field winding outside the slots between the salient poles of the rotor. can be made larger, and circuit loss due to heat generation in the field winding can be suppressed accordingly, and an improvement in the output of the electric machine can be expected. The configuration of the present invention may be applied to various rotating electric machines having a rotor wound with field windings.

Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the invention.

FIG. 1 is a schematic diagram of end faces of a rotor and a stator as seen from the direction of the rotation axis of a preferred embodiment of a rotating electrical machine according to the present invention, and a schematic perspective view of an annular member (the scale at the lower left is different from the end view). ). 2A and 2B are schematic side and cross-sectional views of salient pole portions of the rotor of the rotary electric machine according to the present embodiment, respectively, viewed from a direction perpendicular to the rotation axis. 2(A) is a diagram viewed from the dashed line in the direction of the arrow F2A in FIG. 1, and FIG. 2(B) is a diagram viewed from the dashed line in the direction of the arrow F2B in FIG. 3A and 3B are schematic cross-sectional views of the rotor and stator of the rotating electric machine according to the present embodiment and a similar conventional rotating electric machine, viewed from the direction of the rotation axis (upper). and a schematic diagram of the slot area (bottom). The field current ib flows perpendicularly to the paper surface in the slots between the salient pole portions, and flows along the paper surface when straddling adjacent slots. FIG. 4 is a schematic view of part of the end face of the rotor of another embodiment of the rotating electric machine according to the present invention, viewed from the direction of the rotation axis. FIG. 5 is a part of the end face of the rotor viewed from the direction of the rotation axis of the rotating electric machine according to the present invention, showing the outer circumference of the field winding and the inner circumference of the umbrella-shaped portion at the tip of the salient pole. It is a schematic diagram of the state in which the clearance gap is provided in between.

REFERENCE SIGNS LIST 1 rotating electric machine 2 stator 3 stator tooth 4 armature winding 5 rotor 6 rotor salient pole portion 6a outer end portion (umbrella-shaped portion) of rotor salient pole portion
7 Field winding 7a Portion of field winding protruding from salient pole in rotation axis direction 8 Annular member (reinforcing member)
10... Rotor shaft C... Axis of rotation

Structure of Rotating Electric Machine Referring to FIGS. 1 and 2(A) and (B), the basic structure of the rotating electric machine 1 of the preferred embodiment of the present invention is the structure of a rotating field synchronous machine in a normal manner. can be Specifically, in the rotating electric machine 1, the armature winding 4 is arranged in slots between a plurality of stator teeth formed along the inner peripheral surface of the stator 2, while the rotation axis In the rotor 5 mounted on the rotating shaft 10 that rotates around C, a plurality of salient poles 6 are provided at equal angular intervals (in the illustrated example, every 45°) in the circumferential direction, A field winding 7 is wound on each salient pole portion 6 so as to extend in a plane direction perpendicular to the radial direction from the rotation axis C. As shown in FIG. Further, normally, the outer peripheral end portion 6a of the salient pole portion 6 is formed in the shape of an umbrella (in the cross section in the direction perpendicular to the rotation axis C) and is wider than the root region thereof, and the magnetic field is formed around the rotor. is effectively generated in torque generation, and is configured to prevent the field winding 7 from falling off from the salient pole portion 6 . Further, in the case of this embodiment, as will be described in detail below, an annular member 8 as depicted in the lower left of FIG. It is attached so as to be fitted to the outer peripheral surface of the portion 7a projecting from the portion 6 (in the direction perpendicular to the radial direction from the axis of rotation). In addition, the annular member 8 may be provided at both ends of the rotor in the rotation axis direction (or only one of them).

Retaining Mechanism for Field Winding In the case of the rotating field synchronous machine in which the field winding is wound around the salient pole portions of the rotor as described above, each salient pole portion 6 has a magnetic field coil. Since the windings 7 are wound in a direction in which the central axis extends along the radial direction of the rotor 5 , when the rotor 5 rotates, centrifugal force causes the field windings 7 to move toward the salient pole portions 6 . Acts in the direction of radial movement of the rotor above. Therefore, a mechanism is required to hold the position of the field winding 7 on the salient pole portion 6 against such centrifugal force. Regarding this point, in the case of the conventional configuration, as shown in FIG. The outer peripheral end portion 6a is formed thick so as to be applied to the umbrella-shaped outer peripheral end portion 6a of the contacting salient pole portion 6 . Alternatively, as in Patent Document 1, another projecting portion is formed between adjacent salient pole portions, and a holding member is suspended between the salient pole portions and the projecting portion to limit the movement of the field winding. things were being done.

By the way, in the rotating electric machine 1 in which the field winding 7 is wound around the salient pole portions 6 of the rotor 5 as described above, the magnetic field is formed by passing an electric current through the field winding 7. The higher the electrical resistance in the magnetic winding 7, the greater the Joule heat and the greater the loss. Therefore, it is preferable that the electrical resistance in the field winding 7 be as low as possible. In this regard, the area around which the field winding 7 is wound is within the slot, which is the space between the salient poles, and the field winding 7 extends parallel to the rotation axis C in the slot. Therefore, the larger the area that can be occupied by the field winding 7 in the plane perpendicular to the rotation axis C, the more the electrical resistance can be reduced. It is possible to increase the wire diameter and reduce the electrical resistance of the winding, or increase the number of turns to increase the magnetic field.). That is, in the rotary electric machine 1, the larger the slot area, that is, the area of the cross section of the slot in the direction perpendicular to the rotation axis C, the more the electrical resistance in the field winding 7 can be reduced. Advantageously, field current losses are reduced. Therefore, from the viewpoint of loss reduction, it is preferable that the outer peripheral end portion of the salient pole portion 6 is as thin as possible, and it is preferable that there are no constituent elements other than the field winding in the slot. .

Therefore, in this embodiment, as a mechanism for holding the position of the field winding 7 above the salient pole portion 6 against the centrifugal force generated when the rotor rotates, the annular member 8 is provided as described above. is attached to the outer circumference of the portion 7a of the field winding 7 protruding from each salient pole portion 6 in the rotation axis direction. With such a configuration, the annular member 8 restricts the radially outward movement of the rotor of the field winding 7, and the position of the field winding 7 on the salient pole portion 6 is maintained. Become. In particular, even if the centrifugal force during rotation of the rotor acts on the field winding 7, the effect is canceled by the centrifugal force in the opposite direction or another direction through the annular member 8. Displacement of the field winding 7 can be suppressed more reliably than when a member is separately attached to each winding. Also, what is important is that the stress acting on the outer peripheral end portion 6a of the salient pole portion 6 can be relaxed, so that the outer peripheral end portion 6a can be formed thinner. As a result, comparing FIGS. 3A and 3B, the slot area a in the configuration (FIG. 3A) to which the annular member 8 according to the present embodiment is applied is The slot area can be made larger than the slot area b in the configuration (FIG. 3(B)) held by the outer peripheral end portion 6a. can be reduced, and the loss can be reduced. In addition, in the case of this embodiment, since the annular member 8 is attached outside the slot, the annular member 8 does not reduce the area that can be occupied by the field winding 7 within the slot area. Advantageous.

The annular member 8 may be made of any non-magnetic material such as carbon fiber material, resin material, or non-magnetic metal material. The shape of the annular member 8 may be an annular shape as shown in FIG. 1, a polygonal annular shape as shown in FIG. 4, or a combination thereof (not shown). The width and thickness of the annular member 8 may be adapted to provide sufficient strength.

Since the outer peripheral surface of the bundle of the field winding 7 is held by the annular member 8, as shown in FIG. A gap δ may be provided. In that case, since the stress from the field winding 7 does not act on the outer peripheral end portion 6a, the outer peripheral end portion 6a may be formed to be thinner, or the required rigidity can be reduced. This is advantageous in that it is possible to reduce the amount of heat and save materials.

Although the above description has been made with respect to the embodiments of the present invention, many modifications and changes can be easily made by those skilled in the art, and the present invention is limited only to the above-exemplified embodiments. It will be clear that the invention is non-limiting and can be applied to a variety of devices without departing from the concept of the invention.

Claims (1)

The rotor has a plurality of salient pole portions projecting radially along its circumferential direction, and a field winding is provided on each salient pole portion along a direction perpendicular to the radial direction of the rotor. In a rotating electric machine that is wound, the outer peripheral surface of the radial direction of the portion of each of the field windings that protrudes from each of the salient pole portions in the rotation axis direction of the rotor. A rotating electric machine, wherein an annular member is provided to surround the rotor along the circumferential direction, and the annular member restricts movement of the field winding in the radial direction of the rotor.

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