JP2013017333A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine that has a fan with excellent manufacturability, light-weight and high performance and reliability.SOLUTION: A rotary electric machine 1 that supplies an excitation current to an excitation coil of a rotor 11 rotated by a prime mover T and causes an induction coil of a stator 12 to generated electric power comprises: collector rings 21; a coupling 22; a fan 23; and a boss 24. The collector rings 21 are mounted on an outer periphery of a shaft 111 of the rotor 11 and there is provided a pair of collector rings 21. The coupling 22 is mounted to an end portion of the shaft 111. The fan 23 is formed integrally with an annular shape that surrounds the outer periphery of the shaft 111 and has an inner periphery diameter R23 greater than outer periphery diameters R21 and R22 of the collector rings 21 and of the coupling 22. The boss 24 is mounted between the pair of collector rings 21 and the fan 23 is fixedly connected thereto in an axial direction of the shaft 111.

Description

  Embodiments described herein relate generally to a rotating electrical machine in which a cooling fan is assembled.

  There is a rotating electrical machine in which an exciter for supplying an exciting current to a coil of a rotor is installed coaxially with the rotor. The exciter includes a collector ring that is attached to the outer periphery of the rotor shaft via an insulating material, a brush that slides on the collector ring to supply an excitation current, a collector cover and a collector cover that covers the brush, and a collector ring And a fan attached to the shaft for cooling the brush and stirring the air in the collector cover.

  The fan has at least a central ring for joining to the shaft and a plurality of blades for generating airflow in the centrifugal direction, and each member is assembled by welding or rivet joining. The fan is manufactured by shrink fitting with the central ring being manufactured with a tight fit dimensional tolerance to the shaft.

Japanese Utility Model Publication No. 60-153897 Special table 2010-525571 gazette

  In many cases, structural members are used as members constituting the fan in consideration of weldability and shrink fitting. However, if the fan is made of steel, the mass increases, so that not only careful swinging is required, but also a lifting device is required when assembling the shaft. In addition, when assembling a fan by welding, various manufacturing processes such as material removal, processing for each part, temporary assembly, welding, inspection, annealing, finishing, distortion removal, and run-out are required, resulting in a high manufacturing unit price. In addition, it requires skilled skills in each process.

  In addition, in order to satisfy the static pressure increase performance required for fans as a design requirement, the blade cross-sectional shape should be streamlined, or if the blade has a uniform thickness, bend or increase the blade area. Or take measures such as increasing the number of wings. If the cross-sectional shape of the blade is streamlined, the number of processing steps for each blade increases, and positioning during assembly becomes difficult. If the blade has a uniform cross section, it is necessary to increase the blade area or increase the number of blades, which further increases the mass of the fan. When the wing area is increased, the outer shape of the fan increases, so the collector cover must be increased accordingly.

  A collector ring and a collector coupling are disposed in the vicinity of the fan, and these are also shrink-fitted on the shaft. Therefore, when it becomes necessary to remove the fan for maintenance after opening, the collector ring and collector coupling must also be removed.

  Therefore, the present invention provides a rotating electrical machine having a fan that is excellent in manufacturability and lightweight, and has high performance and reliability.

  A rotating electrical machine according to an embodiment is a rotating electrical machine that supplies an excitation current to an excitation coil of a rotor rotated by a prime mover to generate electric power in an induction coil of a stator, and includes a collector ring, a coupling, a fan, and a boss. With. The collector ring is mounted on the outer periphery of the rotor shaft extending through the frame that houses the rotor and the stator, and is provided in a pair connected to the excitation coil. The coupling is attached to the end of the shaft. The fan is integrally formed in an annular shape surrounding the outer periphery of the shaft, and has an inner peripheral diameter larger than the outer peripheral diameters of the collector ring and the coupling. The boss is mounted between a pair of collector rings, and a fan is coupled and fixed in the axial direction of the shaft.

Sectional drawing which shows typically the rotary electric machine of 1st Embodiment. Sectional drawing which expanded the periphery of the fan of the rotary electric machine shown in FIG. The side view which notched a part of fan shown in FIG. Sectional drawing of the fan which follows the F4-F4 line | wire in FIG. Sectional drawing which decomposed | disassembled the fan of the rotary electric machine of 2nd Embodiment to the axial direction. Sectional drawing which expanded the connection part of the fan shown in FIG. Sectional drawing which decomposed | disassembled the fan of the rotary electric machine of 3rd Embodiment to the axial direction. The disassembled perspective view of the engaging part of the fan shown in FIG.

  A rotating electrical machine 1 according to a first embodiment will be described with reference to FIGS. 1 to 4. A rotating electrical machine 1 shown in FIG. 1 supplies an exciting current to an exciting coil of a rotor 11 rotated by a prime mover T to generate electric power in an induction coil of a stator 12. The rotor 11 and the stator 12 are accommodated in the frame 13. The inside of the frame 13 is filled with hydrogen gas used as the cooling medium gas G. The end of the rotor 11 extends through the frame 13. In order to seal the cooling medium gas G in the frame 13, a shaft seal device 14 and a bearing 15 are mounted on the shaft 111 of the rotor 11 that penetrates the frame 13.

  The rotating electrical machine 1 includes a collector ring 21, a coupling 22, a fan 23, and a boss 24 as shown in FIG. The collector ring 21 is attached to the outer periphery of the shaft 111 of the rotor 11 extending through the frame 13 by shrink fitting with an insulating material 25 interposed. As shown in FIG. 2, the collector rings 21 are provided in pairs with a distance in the direction along the axis L of the shaft 111, and are connected to both ends of the exciting coil. The coupling 22 is attached to the end of the shaft 111 by shrink fitting.

  As shown in FIG. 2, the fan 23 is formed in an annular and integral manner surrounding the outer periphery of the shaft 111. The boss 24 is mounted between the pair of collector rings 21 by shrink fitting, and the fan 23 is coupled and fixed in a direction along the axis L of the shaft 111. As shown in FIG. 2, the inner peripheral diameter R <b> 23 of the fan 23 is made larger than the outer peripheral diameter R <b> 21 of the collector ring 21 and the outer peripheral diameter R <b> 22 of the coupling 22. Therefore, the fan 23 can be attached to the boss 24 through the end of the shaft 111 with the collector ring 21, the boss 24, and the coupling 22 attached. That is, it is possible to remove only the fan 23 as necessary.

  This fan 23 is machined from one annular forged product made of an aluminum alloy, and as shown in FIGS. 3 and 4, the central ring 231, the plurality of blades 232, and the side ring 233 are cut out integrally. Is formed.

  By adopting a forged product as a material for scraping the fan 23, unlike the casting, there are no pores inside the material, so there is no risk of cracks originating from the pores. There is no need to set a preliminary dimension that takes into account. Accordingly, the reliability of the material is high, and the weight of the fan 23 after processing is reduced. Further, the forged aluminum alloy material used for the fan 23 has a tensile strength of 130 MPa or more. The fatigue strength with respect to the repetitive load applied to the fan when the rotating electrical machine 1 is started and stopped can be set high.

  The center ring 231 includes a thick base portion 231A coupled to the boss 24 and a disk portion 231B extending from the base portion perpendicular to the axis L of the shaft 111. The center ring 231 has a bolt hole 231C that opens in parallel with the axis L in the base portion 231A. The boss 24 has a screw hole 24A corresponding to the bolt hole 231C.

  The fan 23 is fastened to the boss 24 by a bolt 26 that is passed through the bolt hole 231 </ b> C in parallel with the axis L of the shaft 111. When the fan 23 is attached to the boss 24, positioning work is facilitated by attaching guide pins to some screw holes 24A. After the bolts 26 are attached to the other screw holes 24A, the guide pins may be replaced with the bolts 26.

  Further, the fan 23 has screw holes 231D penetrating in parallel with the axis L of the shaft 111 at several locations on the base portion 231A. This screw hole 231 </ b> D is used for mounting a jack bolt when the fan 23 is separated from the boss 24 along the axis L of the shaft 111. As the diameter of the fan 23 increases, it becomes difficult to assemble and remove the fan 23 in parallel with the boss 24. When the fan 23 is assembled to the boss 24, it can be attached relatively smoothly by tightening the bolts 26 evenly. However, when removing the fan 23 from the boss 24, the bolt 26 cannot be used. Therefore, by attaching jack bolts to the screw holes 231D and tightening them evenly, the side face of the boss 24 is pushed with the jack bolts, and the fan 23 is separated from the boss 24.

  Each of the plurality of blades 232 extends in parallel with the axis L of the shaft 111 from both side surfaces of the disk portion 231B of the central ring 231 and has a streamlined cross section. As shown in FIG. 3, each blade 232 is formed at an angle that generates an airflow in the centrifugal direction with respect to the shaft 111 as the fan 23 rotates along with the shaft 111. In the case of the present embodiment, since the blade 232 is cut out by mechanical cutting, the manufacturing cost does not greatly change even if the shape of the blade 232 is streamlined compared to the case where the blade is individually manufactured and welded.

  Since the cross section of the blade 232 is formed in a streamline shape, a sufficient static pressure increase performance can be obtained with a small number of blades 232 as compared with a case where the blade thickness is uniform. Contribute. Further, the blades 232 are formed in a streamline shape, thereby preventing wind noise during rotation.

  The side ring 233 connects the ends of the blades 232 in the circumferential direction along a plane perpendicular to the axis L of the shaft 111 as shown in FIGS. This prevents the blades 232 from vibrating individually while the fan 23 rotates together with the rotor 11.

  In the rotating electrical machine 1 configured as described above, the inner peripheral diameter R23 of the fan 23 is formed larger than the outer peripheral diameters R21 and R22 of the collector ring 21 and the coupling 22. Accordingly, the fan 23 can be assembled even after the collector ring 21, the boss 24, and the coupling 22 are attached to the shaft 111 of the rotor 11 by shrink fitting. At this time, the center ring 231, the blade 232, and the side ring 233 are all cut out by mechanical cutting from the annular forged product without welding, and the fan 23 is formed. Eliminates various incidental operations such as single component processing of each part of the fan, jig setup required for assembly, temporary assembly, welding, annealing for stress relief, distortion removal, inspection of welds, and finishing. Therefore, even if some time is required for machine cutting, the fan 23 can be made at a low total cost. Further, since the fan 23 is made of an aluminum alloy, the fan 23 itself becomes light and the efficiency of the assembly work is improved.

  Furthermore, in the case of a conventional rotating electrical machine in which the boss and the fan are made integrally, the fan had to be attached before and after the work of assembling the collector ring and coupling to the rotor shaft. According to the rotating electrical machine 1 of the embodiment, the boss 24 can be attached first together with the collector ring 21 and the coupling 22, and the fan 23 can be attached later. In other words, the fan 23 can be temporarily removed as necessary in the surrounding work situation. In the manufacturing process of the rotor 11, the degree of freedom of the timing for attaching the fan 23 is increased, and a review of the work procedure and an improvement in handling are expected.

  A rotating electrical machine 1 according to a second embodiment will be described with reference to FIGS. 5 and 6. In each figure, the structure which has the same function as the rotary electric machine 1 of 1st Embodiment attaches | subjects the same code | symbol, and shall consider the description corresponding to 1st Embodiment. As shown in FIGS. 5 and 6, the rotating electrical machine 1 of the second embodiment is different from the rotating electrical machine 1 of the first embodiment in the structure of the connecting portion between the base 231 </ b> A of the fan 23 and the boss 24. The other structure is the same as that of the rotating electrical machine 1 of the first embodiment.

  In the second embodiment, as shown in FIG. 5, the boss 24 has an annular groove 244 that is recessed in a direction along the axis L of the shaft 111 of the rotor 11. The fan 23 has an annular convex portion 234 in the base portion 231 </ b> A that fits in the direction along the axis L of the shaft 111 with respect to the groove 244. The bolt hole 231 </ b> C is formed so as to penetrate the convex portion 234 in parallel with the axis L of the shaft 111, and the screw hole 24 </ b> A of the boss 24 is also provided at the bottom of the groove 244.

  Further, in the case of the second embodiment, as shown in FIG. 6, the dimensional relationship of the interference fit in which the outer peripheral diameter D23 of the convex portion 234 of the fan 23 is slightly larger than the inner peripheral diameter D24 of the groove 244 of the boss 24. Is formed. Therefore, when the fan 23 is assembled to the boss 24, the fan 23 is mounted by cold fitting. Alternatively, the studs 234 of the fan 23 and the grooves 244 of the boss 24 are attached to several locations where the screw holes 24 </ b> A of the boss 24 are evenly arranged using the studs sufficiently long with respect to the fitting strokes of the grooves 244 of the boss 24. You may assemble so that the fan 23 may be press-fit with respect to the boss | hub 24 with the attached nut.

  As described above, since the outer diameter D23 of the convex portion 234 of the fan 23 is provided in the dimensional relationship of the interference fit larger than the inner diameter D24 of the groove 244 of the boss 24, the centrifugal force acting on the fan 23 is increased. It is possible to prevent the fan 23 from being eccentric.

  A rotating electrical machine 1 according to a third embodiment will be described with reference to FIGS. 7 and 8. In each figure, the structure which has the same function as the rotary electric machine 1 of 1st and 2nd embodiment attaches | subjects the same code | symbol, and considers the description corresponding to 1st and 2nd embodiment. As shown in FIGS. 7 and 8, the rotating electrical machine 1 according to the third embodiment is engaged in positioning in the rotational direction of the shaft 111 between the outer periphery of the convex portion 234 of the fan 23 and the outer periphery of the groove 244 of the boss 24. The point which has a part differs from 2nd Embodiment.

  In the third embodiment, as the engaging portion, a protrusion 235 is formed on the outer periphery of the convex portion 234 of the fan 23, and a notch 245 corresponding to the protrusion 235 is formed on the outer periphery of the groove 244 of the boss 24. The relationship between the protrusions 235 and the notches 245 may be reversed. Further, instead of providing the engaging portion, a positioning hole may be provided in each of the fan 23 and the boss 24, and a pin or a key may be inserted into this hole. Further, instead of the protrusions 235 and the notches 245, flat portions may be formed in the convex portions 234 of the fan 23 and the grooves 244 of the bosses 24 so that parts of the arcs are linearly processed to match each other.

  By providing engaging portions (protrusions 235 and notches 245) for positioning in the rotation direction of the shaft 111 in the convex portion 234 of the fan 23 and the groove 244 of the boss 24, the fan 23 and the boss 24 It is possible to prevent the fan 23 from being displaced even when a circumferential force is applied between them.

  Although several embodiments of the present invention have been described, these embodiments are 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 1 ... Rotary electric machine, 11 ... Rotor, 111 ... Shaft, 12 ... Stator, 13 ... Frame, 21 ... Collector ring, 22 ... Coupling, 23 ... Fan, 231 ... Center ring, 231D ... Screw hole, 232 ... Wing 233 ... side ring, 234 ... convex part, 24 ... boss, 244 ... groove, 235 ... projection (engagement part), 245 ... notch (engagement part), R21 ... outer diameter of collector ring, R22 ... Peripheral diameter (of coupling), R23... (Inner) inner diameter, D23 (outer) outer diameter, D24 (inner groove) inner diameter.

Claims (6)

A rotating electrical machine that supplies an excitation current to an excitation coil of a rotor rotated by a prime mover to generate electric power in an induction coil of a stator,
A pair of collector rings attached to the outer periphery of the shaft of the rotor extending through a frame housing the rotor and the stator and connected to the excitation coil;
A coupling attached to the end of the shaft;
A fan integrally formed in an annular shape surrounding the outer periphery of the shaft and having an inner peripheral diameter larger than the outer peripheral diameter of the collector ring and the coupling;
A rotating electric machine comprising: a boss mounted between a pair of the collector rings and to which the fan is coupled and fixed in the axial direction of the shaft. The fan includes a central ring coupled to the boss, and a plurality of blades having a streamlined cross section that extends parallel to the axis of the shaft relative to the central ring and generates an airflow in a centrifugal direction relative to the shaft. The rotating electrical machine according to claim 1, wherein the rotating electrical machine is formed by integrally cutting a side ring that connects the end portions of the blades in a circumferential direction along a plane perpendicular to the axis of the shaft. . The boss has an annular groove recessed in the axial direction of the shaft,
3. The rotating electrical machine according to claim 1, wherein the fan has an annular protrusion that fits in the axial direction of the shaft with respect to the groove. The rotating electrical machine according to claim 3, wherein the outer peripheral diameter of the convex portion and the inner peripheral diameter of the groove are formed in an interference fit relationship. The rotation according to any one of claims 1 to 4, wherein the fan has a screw hole for mounting a jack bolt that pushes the fan away from the boss in the axial direction. Electric. The rotating electrical machine according to any one of claims 1 to 5, wherein the fan and the boss include an engaging portion that is positioned in a rotation direction of the shaft.

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