Stator coil support device for electric rotating machinery

Abstract: An electric rotating machinery is provided with a stator coil support device, which comprises a stator core (10) provided with a slot (11) having an opening, a stator coil (12) installed in the slot (11) of the stator core (10), a wedge member (14) disposed so as to close the opening of the slot (11) of the stator core (10), and an elastic plate member (13) inserted between the stator coil (12) and the wedge member (14). The wedge member (14) is formed so as to have an inclination towards an axial direction of the stator core (10) and the elastic plate member (13) has a structure undulating towards the axial direction.

Description: The present invention relates to a stator coil support device of an electric rotating machinery wherein an elastic member is inserted between a stator coil and a wedge. In the most recent electric rotating machineries such as turbine generators, it has become possible to increase capacity (output) thereof, as compared with the prior art, in accordance with the progressing of cooling technology. However, the increasing capacity of turbine generators has brought about an abrupt increase in the current flowing in the stator coil. Consequently, electromagnetic vibrations of double frequency are generated in the slot of the stator core in which the stator core is installed during normal operation. In the event of an abnormal operation at a time, for example, when a short circuit or the like occurs, an excessive transient electromagnetic force is generated. In a conventional turbine generator, such abnormal phenomenon has been dealt with by adopting a structure shown in Figs. 13 to 16 for the stator coil support device. With reference to Figs. 13 to 16, in the stator coil support device, a stator coil 3 is installed in a slot 2 of a stator core 1 constituted by superimposing thin sheets, for example, sheets of silicon steel, along an axial direction thereof and, at one end of the stator coil 3 installed in the slot 2, as shown by way of example in Figs. 13 to 15, the slot 2 has an opening which is closed by a wedge 6 having inclined surfaces, with an elastic plate 4 and a sliding plate 5 formed with an inclined shape being inserted therein. The elastic plate 4 is called a ripple spring that is formed as an undulating (wave-shaped) laminated plate, which is formed by hot press forming a thermosetting resin such as phenol or epoxy resin with cotton or glass cloth, etc. serving as a base material. The electromagnetic vibrations generated during operation are arranged to be suppressed by skillfully utilizing the elastic force provided by the undulations of the elastic plate 4. Further, in the conventional stator coil support device, the electromagnetic vibrations are suppressed in the same way as described above by mounting the elastic plate 4 as shown in Fig. 15 also on the side surface of the stator coil 3 shown in Fig. 13 with an insulating layer, not shown, being inserted therein. In this way, in the conventional stator coil support device, the electromagnetic vibrations are suppressed, and damage to the insulating layer is prevented by the elastic force of the undulation (wave-shape) of the elastic plate 4 which is inserted in the gap between the wedge 6 and the stator coil 3 installed in the slot 2 of the stator core 1 and, in addition, the electrical loss of the like that accompanies the formation of the gap also has been prevented. U.K. Patent Publication No. 2 268 337 describes an electrical machine slot wedging system similar to Figures 13-16, in which a ripple spring is sandwiched between a pair of co-operating wedge means and a conductor. Although the prior art stator coil support device shown in Figs. 13 to 16 is excellent in the point of well suppressing electromagnetic vibrations generated in the slot of the stator core, the prior art still has the following problems. In order to suppress vibrations of the stator coil 3, the conventional stator coil support device requires the elastic plate 4, the sliding plate 5 and the wedge 6, as described above. However, if the structural components of the stator coil support device become large in number, the time required for assembling the components increases and more time is spent in the assembling operation, which has repercussions on costs, leading to a problem of high cost. In particular, in regard to the structural components employed in the stator coil support device, it is required for a worker to simplify the operation, because the assembling operation is usually performed in a restricted location. An object of the present invention is to substantially eliminate defects or drawbacks encountered in the prior art mentioned above and to provide a stator coil support device for electric rotating machinery (rotary electric machine) in which simplification of the assembling operation is achieved by reducing the number of structural components. This and other objects can be achieved according to the stator coil support device of claim 1. Additional developments of the invention are provided by sub-claims 2-10. In preferred embodiments of the inventions the elastic member has a plate structure having a plurality of wave-peaks which have heights gradually increasing along the axial direction of the stator core. The wedge member has an inclination towards the axial direction of the stator core in a range of not less than 0° but not more than 10° . The elastic member has a plate structure having an inclination towards the axial direction of stator core in a range of not less than 0 ° but not more than 10° . The recess is formed in a trapezoidal shape. The wedge member is formed in a polygonal shape so as to be fitted into the recess formed in the elastic member by utilizing sides of the polygonal shape. The elastic member has a plate structure made of glass fiber reinforced plastic material. The elastic member has a plate structure made of non-magnetic stainless-steel material. According to the stator coil support device for the electric rotating machinery according to the present invention, the stator coil installed in the slot of the stator core can be supported by the wedge with the elastic plate being inserted. Therefore, the number of structural components can be reduced, so that the assembling operation can be facilitated, thus making it possible to shorten the time required for the assembling operation compared with the conventional technology. The nature and further characteristic features of the present invention will be made more clear from the following description when read with reference to the accompanying drawings. In the accompanying drawings: Fig. 1 is a perspective view illustrating a first embodiment of a stator coil support device for electric rotating machinery according to the present invention; Fig. 2 is a schematic longitudinal section taken along line II-II of Fig. 1; Fig. 3 is a view illustrating an elastic plate employed in the first embodiment of a stator coil support device for electric rotating machinery according to the present invention; Fig. 4 is a front view illustrating a second embodiment of a stator coil support device for an electric rotating machinery according to the present invention; Fig. 5 is a side view seen in the direction of arrows V-V of Fig. 4; Fig. 6 is a perspective view illustrating an elastic plate applied to the second embodiment of a stator coil support device for electric rotating machinery according to the present invention; Fig. 7 is a view illustrating a modified example of the elastic plate applied to the stator coil support device; Fig. 8 is a side view seen in the direction of arrows VIII-VIII of Fig. 7; Fig. 9 is a front view illustrating a third embodiment of a stator coil support device for electric rotating machinery according to the present invention; Fig. 10 is a side view seen in the direction of arrows X-X of Fig. 9; Fig. 11 is a view illustrating the elastic plate applied to the third embodiment of a stator coil support device; Fig. 12 is a side view seen in the direction of arrows XII-XII of Fig. 11; Fig. 13 is a front view illustrating one example of a conventional stator coil support device for electric rotating machinery; Fig. 14 is a side view seen from the direction of arrows XVII-XVII of Fig. 13; Fig. 15 is a front view illustrating another example of a conventional elastic plate applied to a stator coil support device for electric rotating machinery; and Fig. 16 is a perspective view illustrating a further example of a conventional stator coil support device for electric rotating machinery. Hereunder, embodiments of a stator coil support device of an electric rotating machinery according to the present invention will be described by way of preferred examples with reference to the accompanying drawings. Fig. 1 to Fig. 3 are diagrams illustrating a first embodiment of a stator coil support device for electric rotating machinery according to the present invention. With reference to Figs. 1 to 3, the stator coil support device for electric rotating machinery according to this embodiment has a construction in which a stator coil 12 is installed in a slot 11 of a stator core 10 formed by overlaying thin sheets, for example, silicon steel sheets, along the axial direction of the stator core 10, and an opening of the slot II is closed by a wedge (wedge means) 14 having an inclined surface with the elastic plate 13 being inserted at one end of the stator coil 12 in a manner shown in Fig. 2. The elastic plate 13 is formed, through a hot pressing of thermosetting resin such as phenol or epoxy resin, by using, as a base material, cotton or glass cloth as shown in Fig. 3. The elastic plate 13 has a plurality of peaks of (mount portions) formed by using an undulating (wave-shaped) laminated plate, the peaks increasing in height in the axial direction of the stator core. Further, the elastic plate 13 may be manufactured or made of a glass fiber reinforced plastic material or a non-magnetic stainless steel material. As shown in Fig. 2, the wedge 14 is manufactured through a molding process with an angle of inclination such that its thickness decreases in the axial direction of the stator core. This angle of inclination is not less than 0° and not more than 10°. This numerical range is a preferred applicable range which was determined by experimentation. In this embodiment, the stator coil 12 is supported by the wedge 14 which is molded and processed with an angle of inclination so as to decrease its thickness in the axial direction thereof, and the undulating (wave-shaped) laminated elastic plate 13 having a plurality of peaks, which become higher in the axial direction, is inserted. Accordingly, even if electromagnetic vibration is generated in the stator coil 12, the elastic force of the elastic plate 13 having a plurality of peaks and the frictional force that accompanies the increase in contact area of the wedge 14 formed with such angle of inclination as mentioned above can be effectively utilized, thereby suppressing vibrations. Furthermore, in this embodiment, the elastic plate 13 is molded and processed with a plurality of peaks so as to become higher in the axial direction, and, on the other hand, the wedge 14 is molded and processed so as to become accordingly thinner in the axial direction. Accordingly, the number of structural components can be reduced, and, as well as controlling vibration, the assembling operation can be facilitated, thereby enabling the time required for the assembling operation to be shortened as compared with the conventional technology. Fig. 4 to Fig. 6 are views representing a second embodiment of a stator coil support device for electric rotating machinery according to the present invention, in which like reference numerals identify the portions or components corresponding to those of the first embodiment and the details thereof are omitted herein. In the stator coil support device for electric rotating machinery according to this second embodiment, the stator coil 12 that is installed in the slot 11 of the stator core 10 is supported by the elastic plate 13 and the wedge 14, as clearly shown in Fig. 6. The elastic plate 13 is formed with one or more recesses 15 at a central portion having a trapezoidal shape in its cross sectional area, and flat flanges 16a, 16b are provided on both sides thereof. As shown in Fig. 5, the elastic plate 13 is molded and processed with an inclined side 17 having an angle of inclination of not less than 0° and not more than 10° with respect to the axial plane. Furthermore, as shown in Fig. 5, the wedge 14 is molded and processed with an angle of inclination of not less than 0° and not more than 10° towards the axial direction so as to accord with the inclined side 17 of the elastic plate 13. Thus, in this embodiment, the elastic plate 13 is molded and processed so as to be provided with one or more trapezoidal recesses 15 at the central portion thereof, and the flat flanges 16a, 16b are formed on both sides thereof with an inclined side 17 having an angle of inclination of not less than 0° and not more than 10° with respect to the axial plane. On the other hand, the wedge 14 has an angle of inclination of not less than 0° and not more than 10° in the axial direction so as to accord with the shape of elastic plate 13. Accordingly, the number of structural components can be reduced, and moreover, in accordance with the increase in compressive force with respect to the external force from outside at the time of molding, the recess 15 of the elastic plate 13, the assembling operation can be facilitated and the time required for the assembling operation can be shortened as compared with the conventional technology. Although, in the described embodiment, the trapezoidal recess 15 is formed at the central portion of the cross-section of the elastic plate 13 and the flat flanges 16a and 16b are provided on both sides thereof, there is no restriction to this example. For example, as shown in Fig. 7, it could be molded and processed into a split-type cylinder 18 with an inclined surface having an angle of inclination in the range of 0° to 10° in the axial direction as shown in Fig. 10. Fig. 9 to Fig. 12 are views representing a third embodiment of a stator coil support device for electric rotating machinery according to the present invention, in which like reference numerals identify the portions or components corresponding to those of the first embodiment and the details thereof are omitted herein. In a stator coil support device for electric rotating machinery according to this third embodiment, when the stator coil 12 installed in the slot 11 of the stator core 10 is supported by interposing the elastic plate 13 and the wedge 14 which are shown in Fig. 11, the elastic plate 13 is formed with at least one or more trapezoidal recesses 15 at the central portion of its cross-section, and flat flanges 16a, 16b are provided on both sides thereof. As shown in Fig. 12, the elastic plate 13 is molded with an inclined side 17 having an angle of inclination of not less than 0° and not more than 10 ° with respect to the axial plane. Furthermore ratchet-like ratches 19a are formed on the flanges 16a, 16b. As shown in Fig. 10, the wedge 14 is molded so as to provide an angle of inclination of not less than 0° and not more than 10° in the axial direction so as to accord with the inclined side 17 of the elastic plate 13 and is formed with the ratchet-like ratches 19b so as to accord with the flanges 16a, 16b of the elastic plate 13. According to the manner mentioned above, in the present embodiment, the elastic plate 13 in the elastic plate 13 and the wedge 14 which support the stator coil 12 is provided with one or more trapezoidal recesses 15 in cross-section and the ratches 19a are provided in the flat flanges 16a, 16b on both sides thereof. On the other hand, the wedge 14 has an angle of inclination of not less than 0° and not more than 10° in the direction of the axial plane so as to accord with the shape of the elastic plate 13 and is equipped with the ratches 19a. Accordingly, the number of structural components can be reduced and, as a result, the assembling operation can be facilitated while preventing the separation of the elastic plate 13 from the wedge 14 due to the engagement of the ratches 19a of the elastic plate 13 with the ratchets 19b of the wedge 14. Thus, the time required for the assembling operation can be shortened as compared with the conventional technology. All the examples are beneficial in that the number of structural components is reduced and, hence, facilitates the assembling operation, and the spatial distance in the vertical direction of the stator coil 12 and the slot 11 is reduced, thereby enabling the conductor installing area ratio of the stator coil 12 to be increased. Further, it is to be noted that the present invention is not limited to the described embodiments and many other changes and modifications may be made without departing from the scope of the appended claims.

Claims: A stator coil support device for electric rotating machinery, comprising: a stator core (10) provided with a slot (11) having an opening; a stator coil (12) installed in the slot of the stator core; a wedge member (14) disposed so as to close the opening of the slot of the stator core; and an elastic member (13) inserted between the stator coil and the wedge member, wherein the wedge member (14) is formed so as to have an inclination in an axial direction of the stator core, characterized in that : the elastic member (13) has a plate structure with a reverse inclination in the axial direction of the stator core so as to accord with the inclination of the wedge member. A stator coil support device for electric rotating machinery according to claim 1, wherein the plate structure of the elastic member (13) is a structure undulating in the axial direction of the stator core (10) and has a plurality of wave-peaks, which have heights gradually increasing along the axial direction of the stator core (10). A stator coil support device for electric rotating machinery according to claim 1, wherein the elastic member (13) has a recess (15), in cross-section, at a central portion thereof, and flanges (16a, 16b) are provided on both sides of the recess and the flanges are inclined in the axial direction of the stator core (10). A stator coil support device for electric rotating machinery according to claim 3, wherein the elastic member (13) is formed as a split cylinder structure (18). A stator coil support device for electric rotating machinery according to claim 1, wherein the wedge member (14) is provided with ratchets (19b) on its inclined side, and wherein the elastic member (13) has a recess (15), in a cross-section, at a central portion thereof, flanges (16a, 16b) are provided on both sides of the recess and ratchets (19a) are provided on the flanges, wherein the flanges are inclined in the axial direction of the stator core (10). A stator coil support device for electric rotating machinery according to claim 3 or 5, wherein the recess (15) is formed so as to provide a trapezoidal shape in cross-section. A stator coil support device for electric rotating machinery according to any one of claims 1-6, wherein the inclination of the wedge member (14) in the axial direction of the stator core (10) is in a range of not less than 0° but not more than 10°. A stator coil support device for electric rotating machinery according to any one of claims 1-7, wherein the reverse inclination of the elastic member (13) in the axial direction of stator core (10) is in a range of not less than 0° but not more than 10°. A stator coil support device for electric rotating machinery according to any one of claims 1-8, wherein the elastic member (13) is made of a glass fiber reinforced plastic material. A stator coil support device for electric rotating machinery according to any one of claims 1-9, wherein the elastic member (13) is made of a non-magnetic stainless-steel material.

Inventors: ASO TOSHIYUKI, HATANO HIROSHI, HIRAI HISAYUKI, IWATA NORIYUKI, MURAYAMA KIYOKO, TSUCHIYA HIROYOSHI, YOSHIDA KATSUHIKO, ASO, TOSHIYUKI, HATANO, HIROSHI, HIRAI, HISAYUKI, IWATA, NORIYUKI, MURAYAMA, KIYOKO, TSUCHIYA, HIROYOSHI, YOSHIDA, KATSUHIKO
Applicants: TOSHIBA KK, KABUSHIKI KAISHA TOSHIBA
Application year: 2001
Main classification: H02K3
IPC codes: H02K3, H02K15, H01F5