JP6457900B2 - Rotating electrical machine rotor - Google Patents

Description

  Embodiments described herein relate generally to a rotor of a rotating electrical machine having an improved coil end structure composed of a rotor bar.

  A rotor of a rotating electrical machine is configured by fitting and fixing a cylindrical iron core in which thin steel plates are laminated to a rotating shaft. A large number of slots are formed on the outer peripheral side of the iron core, and a rotor bar is inserted and fixed in each slot. Ring-shaped short-circuit rings are connected to both ends of these rotor bars. Thermal expansion and centrifugal force are generated in the rotor bar and the short-circuit ring by energization and rotational force during operation of the rotating electrical machine. For this reason, the short-circuit ring swells and deforms in the radial direction, and the stress acting on the rotor bar increases. In order to suppress this state, a structure in which a ring-shaped holding ring is fitted to the outer peripheral portion of the short-circuit ring has been proposed (see, for example, Patent Document 1).

  In the above-described configuration, when a centrifugal force is applied by rotation during operation, the connection configuration between the short-circuit ring and the end portion of the rotor bar is applied as a force in the separation direction, so that there remains anxiety in the connection configuration. For this reason, a coil end structure as shown in FIG. 3 is adopted. That is, a notch is provided on the inner diameter side of the end portion of the rotor bar 32 protruding from the end face of the rotor core 31, and the short-circuit ring 33 is fitted into the notch. A retaining ring 34 is fitted on the outer surface side of the rotor bar 32.

  With this configuration, when the short-circuit ring 33 expands in the radial direction due to centrifugal force, the expansion force in the radial direction acts in a direction to pressurize the connection portion with the rotor bar 32, so that the connection state can be reliably maintained. Further, the force that the end of the rotor bar 32 tends to deform outward due to centrifugal force is firmly held by the retaining ring 34 fitted on the outer side, and the above-described deformation can be prevented.

  However, even in such a configuration, in the high-speed rotation region where the rotation speed reaches 3600 rpm or more, a strong centrifugal force is applied, so that it is difficult to suppress the deformation of the rotor bar 32 because the holding ring 34 expands outward. .

JP-A-8-266024

  As described above, in the conventional configuration, when a strong centrifugal force is applied in the high-speed rotation region, the centrifugal force cannot be suppressed by the retaining ring, and the rotor bar may be deformed.

  An object of the present invention is to provide a rotor of a rotating electrical machine having a coil end structure that can prevent deformation of a rotor bar even against a strong centrifugal force in a high speed region.

The rotor of the rotating electrical machine according to the embodiment of the present invention includes a cylindrical rotor core that is concentrically attached to the outer periphery of the rotating shaft and a circumferential portion near the outer periphery of the rotor core in the axial direction. A plurality of rotor bars penetrating through both ends of the rotor core and projecting from both end faces of the rotor core; and a short-circuit ring coupled to the inner peripheral portion of the ring formed by the projecting ends of the plurality of rotor bars, A retaining ring that fits to the outer peripheral portion of the ring formed by the protruding ends of the plurality of rotor bars, and the retaining ring has an L-shaped cross section with its one side edge bulging to the inner diameter side. In the state where the protruding end surface of each rotor bar is covered with the bulging portion toward the inner diameter side, the outer peripheral portion is fitted , and the short-circuiting ring has a notch formed on the outer peripheral side of the tip portion. And the inner peripheral part of the bulging part of the retaining ring is fitted into this notch. It is characterized by being included .

  According to the above configuration, the deformation of the rotor bar can be suppressed by the retaining ring even against a strong centrifugal force in the high-speed rotation region.

It is a figure which shows schematic structure combining the rotor of the rotary electric machine which concerns on one Embodiment of this invention with a stator. It is a figure which shows the principal part structure of the rotor of the rotary electric machine which concerns on one Embodiment of this invention. It is a figure which shows the principal part coil end structure of the conventional rotor.

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

  First, a schematic configuration of the stator and the rotor constituting the rotating electrical machine will be described with reference to FIG. FIG. 1 illustrates the case of a three-phase induction motor as a rotating electrical machine, and includes a stator 11, a rotor 12, and a rotating shaft 13. The stator 11 includes a cylindrical stator core 14 and a primary winding 15 (only a winding end portion is illustrated), and is provided in a body frame (not illustrated).

  The rotor 12 includes a cylindrical rotor core 17 that is concentrically and integrally attached to the outer periphery of the rotating shaft 13. The outer peripheral surface of the rotor core 17 is opposed to the inner peripheral surface of the cylindrical stator core 14 described above via a gap. Further, near the outer periphery of the rotor core 17, a plurality of slots (not shown) along the axial direction are formed in parallel with each other at equal intervals, and a rotor bar constituting the secondary winding is formed therein. 18 are installed. That is, the plurality of rotor bars 18 penetrate the circumferential portion near the outer periphery of the cylindrical rotor core 17 in the axial direction, and both end portions thereof protrude from both end faces of the rotor core 17, respectively. The coil end structure 20 is configured as shown in FIG.

  2 schematically shows the coil end structure 20 on one end side of the rotor 12 shown in FIG. 1 in an easy-to-understand manner. In FIG. 2, the coil end structure 20 includes a short-circuit ring 21 and a holding ring 22 provided at the end of the rotor bar 18.

  Here, the protruding ends of the plurality of rotor bars 18 are arranged in an annular shape when viewed in the end face direction of the rotor core 17. The short-circuit ring 21 is coupled to the inner peripheral portion of the ring formed by the protruding ends of the plurality of rotor bars 18 described above, and short-circuits between the rotor bars 18. That is, a notch is provided on the inner diameter side of the end portion of the rotor bar 18, and the short-circuit ring 21 is fitted in the notch.

  The retaining ring 22 is fitted to the outer peripheral portion of the ring formed by the protruding ends of the plurality of rotor bars 18. The holding ring 22 has a side section (left side in the figure) bulged toward the inner diameter side (lower side in the figure) and has a L-shaped cross section. When attaching to the rotor bar 18, the protruding ends of the plurality of rotor bars 18 are formed in a state where the protruding end surfaces (the left end surfaces in the drawing) of the respective rotor bars 18 are covered by the above-described bulged portion 22a toward the inner diameter side. To be fitted to the outer periphery of the ring.

  At this time, a notch is formed on the outer peripheral side (the upper part in the figure) of the tip part (the left end part in the figure) of the short-circuiting ring 21, and the inner peripheral part of the bulging part 22a of the holding ring 22 is connected to the short-circuiting ring 21 as shown. It is good to comprise so that it may fit in the above-mentioned notch formed.

  In such a configuration, when the rotor 12 rotates at a high speed reaching 3600 rpm or more, a strong centrifugal force is applied to the coil end structure 20 portion.

  In the conventional coil end structure shown in FIG. 3, since the cross section of the retaining ring 34 is flat as shown in the drawing, there is a problem that the rotor bar 32 is deformed to the outside due to bulging outward due to strong centrifugal force. It was. Of course, if the thickness of the cross section of the retaining ring 34 is increased, such swelling can be prevented, but if the thickness of the entire retaining ring 34 is increased, the size and weight of the parts are increased. Further, since an expensive metal material is used for the retaining ring 34, a significant cost increase is caused.

  On the other hand, in the embodiment of the present invention, as described above, the holding ring 22 constituting the coil end structure 20 is traversed by bulging one side edge (left side in the figure) to the inner diameter side (lower side in the figure). Since the surface is formed in an L shape, strong centrifugal force applied to the coil end structure 20 can be suppressed, and deformation of the rotor bar 18 outward can be effectively prevented. Further, since the thickness of the entire retaining ring 34 is not increased, the parts are not significantly increased in size and weight, and the cost is not significantly increased.

  Here, the force that swells outward due to the centrifugal force applied to the coil end structure 20 along with the high-speed rotation is stronger at the portion closer to the outer side (the left end in the drawing) of the coil end structure 20. Since the holding ring 22 in the embodiment of the present invention has its one side edge (left side in the figure) bulged toward the inner diameter side (lower side in the figure), the mechanical strength of the bulging part 22a is increased. Sufficiently counters the strong centrifugal force associated with high-speed rotation, and suppresses outward expansion. And this holding ring 22 is the outer periphery of the ring which the protrusion end of several rotor bar 18 forms in the state which covered the protrusion end surface (illustration left end surface) of each rotor bar 18 in the bulging part 22a to the inner diameter side mentioned above. Since it is made to fit in the part, the force which the front-end | tip part of the rotor bar 18 tends to deform | transform outward can be suppressed effectively, and the deformation | transformation can be prevented.

  Further, a notch is formed on the outer peripheral side (the upper part in the figure) of the tip part (the left end part in the figure) of the short-circuit ring 21 as shown in the figure, and the inner peripheral part of the bulging part 22a of the holding ring 22 is fitted into this notch. Then, the force that causes the short-circuit ring 21 to expand outward due to centrifugal force can be directly suppressed by the holding ring 22, and the entire coil end structure 20 can be configured firmly.

  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 12 ... Rotor 13 ... Rotating shaft 17 ... Rotor core 18 ... Rotor bar 20 ... Coil end structure 21 ... Short-circuit ring 22 ... Holding ring

Claims (1)

A cylindrical rotor core attached concentrically to the outer periphery of the rotating shaft;
A plurality of rotor bars each penetrating in a circumferential direction near the outer periphery of the rotor core in the axial direction, both ends projecting from both end faces of the rotor core,
A short-circuited ring that is coupled to the inner peripheral portion of the ring formed by the protruding ends of the plurality of rotor bars and short-circuits between the rotor bars,
A holding ring that fits to the outer periphery of the ring formed by the protruding ends of the plurality of rotor bars;
The holding ring has an L-shaped cross section formed by bulging one side edge portion toward the inner diameter side, and covering the protruding end surface of each rotor bar with the bulged portion toward the inner diameter side. It fits around the outer periphery ,
The short-circuit ring has a notch formed on the outer peripheral side of the tip thereof, and the inner peripheral portion of the bulging portion of the holding ring is fitted into the notch. Child.

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