JP6563235B2 - Insulating spacer of rotor of rotating electrical machine - Google Patents

Description

  Embodiments described herein relate generally to a rotating electrical machine, and to an insulating spacer of a rotor of a rotating electrical machine that electrically insulates the shaft end of the rotor from a driving machine side shaft end.

  A rotating electrical machine (for example, a turbine generator) is an element that converts mechanical energy into electrical energy, and the rotor is coupled to the rotor of the drive machine. Here, as one of the driving methods of the generator, there is a double-shaft driving method driven by a turbine (steam turbine or gas turbine) from both sides of the generator.

  FIG. 6 is a diagram showing a connection configuration between a turbine generator and a turbine that employ a double-shaft drive system.

  As shown in the figure, a turbine 52 is connected to one of the turbine generators 51 and a turbine 53 is connected to the other. A turbine shaft 52 b on the turbine generator 51 side of the turbine 52 is provided with a bearing 61 (not insulated), a joint 62 a (not insulated), and a grounding brush 63. A bearing 61 is also provided on the turbine shaft 52 a on the opposite side of the turbine 52.

  The turbine shaft 53a of the turbine 53 on the turbine generator 51 side is provided with two bearings 61, a grounding brush 63, and a joint 62b (electrical insulating portion). A bearing 61 is also provided on the turbine shaft 53 b on the opposite side of the turbine 53.

  A turbine shaft 51a on the turbine 52 side of the turbine generator 51 is provided with a bearing 61 and a joint 62a. The turbine shaft 51b on the turbine 53 side of the turbine generator 51 is provided with an insulating bearing 71 and a joint 62b.

  Here, it is known that a shaft voltage due to magnetic imbalance or the like is generated for the turbine generator 51 and a shaft voltage is generated due to static electricity generated by friction with steam for the turbines 52 and 53. Since voltage causes electric corrosion in the bearing 61 or the like that supports the rotor, a countermeasure is required.

  In general, the shaft voltage generated in the turbine generator 51 is generated as an AC voltage by linking the fluctuation of magnetic flux due to magnetic imbalance with the generator rotor. The structure which prevents that an axial current flows is employ | adopted by performing ground insulation with respect to this bearing.

  Further, the shaft voltage generated in the turbine shaft rises by being charged by static electricity while the rotor is electrically floating via an oil film or the like. Finally, shaft current flows due to dielectric breakdown of the bearing oil film. Therefore, as a countermeasure, as shown in FIG. 7, the turbine shaft is grounded by a grounding brush 63 or the like to prevent the shaft current from flowing to the bearing 61.

  Now, also in the double-axis drive system shown in FIG. 6, a measure for preventing the shaft current is required. Specifically, for the turbines (steam turbines or gas turbines) 52 and 53 located on both sides of the generator 51, a grounding brush 63 (shaft grounding) is essential for each.

  On the other hand, in order to prevent the shaft current due to the shaft voltage generated in the turbine generator 51, one side of the turbine generator 51 needs to be in an electrically floating state, but is required in the turbine shaft. Due to the ground contact portion, it is difficult to achieve this configuration. Therefore, in the double-shaft drive system shown in FIG. 6, it is necessary to couple (joint 62 b (electrical insulation portion)) between the generator 51 and the turbine 53 (drive device) on one side in a state where the shaft is electrically insulated. .

  Next, the problem of the insulating structure in the shaft coupling portion will be described.

  A shaft coupling portion in a drive machine such as a generator or a turbine is loaded with a transmission torque corresponding to the turbine output, and when a short circuit accident or the like occurs, excessive torque is transiently imposed.

  Therefore, it is known that mechanical characteristics are required in the shaft coupling part, and in particular, bolts used for coupling are subjected to fastening work by managing the amount of elongation in order to secure an appropriate axial force. Yes.

  However, when the insulator is inserted in the shaft coupling portion, the insulation of glass or cotton base material shrinks due to long-term deterioration due to long-term deterioration. Axial force may not be maintained.

  In addition, the shaft coupling part is designed to transmit the torque required by the frictional force on the joint surface, but if the insulating surface becomes the joint surface, the friction coefficient may change over time. It is assumed that the allowable transmission torque may be reduced in the future.

  Furthermore, in the shaft coupling part, in order to suppress misalignment between the shafts, an inlay structure (fitting structure) is used on the shaft joint surface, but when the insulating surface becomes a joint surface as described above May not be able to ensure the required dimensional tolerance in the inlay structure.

  Therefore, a structure is known in which insulation in the shaft coupling is realized by an alumina coating by thermal spraying to solve the above-described problem (Patent Document 1).

JP 2003-65006 A

However, in the structure in which the insulation in the above-described shaft coupling is realized by the alumina coating by thermal spraying, the insulating structure type rotor coupling needs to be divided into a plurality of pieces, and each plate needs to be fixed with insulating bolts. . Therefore, there is a problem that workability and adjustment work is deteriorated.

  The present invention has been made in view of the above circumstances, and reliably suppresses the shaft current accompanying the shaft voltage in a configuration in which shaft insulation is required between the generator and the drive device, such as a double shaft drive system. It is an object of the present invention to provide an insulating spacer for a rotor of a rotating electrical machine having an insulating structure capable of ensuring long-term reliability and good workability.

According to the first aspect of the present invention, a shaft coupling portion made of an iron-based material located at an end portion of a main shaft of a rotor of a rotating electric machine, and a shaft made of an iron-based material located at an end portion of the main shaft of a driving machine. In the insulating spacer of the rotor of the rotating electrical machine inserted between the joint part, the rotating electrical machine side made of an iron-based material has an inlay part provided corresponding to the inlay part of the shaft joint part of the rotor a member, an intermediate member made of an iron-based material, has a spigot portion provided corresponding to the fitting portions of the shaft joint hand portion of the drive motor, a drive-side member made of an iron based material, the rotating electrical machine A first insulating member provided only between the side member and the intermediate member, and a second insulating member provided only between the drive unit side member and the intermediate member, and the rotation Electric machine side member, intermediate member, driver side member, first insulating member, second member Edge member is configured to be an integral structure, an insulating spacer of the rotor of the rotary electric machine.

  An insulating spacer for a rotor of a rotating electrical machine having an insulating structure that can ensure long-term reliability and good workability in addition to being able to reliably suppress the shaft current accompanying the shaft voltage Can be provided.

It is a figure which shows the cross section of the insulating spacer 11 of the rotor of the rotary electric machine which concerns on 1st Embodiment. It is a figure which shows the coupling structure of the shaft coupling parts 2 and 4 and the insulating spacer 11 of the rotary electric machine which concerns on 1st Embodiment. It is a figure which shows the cross section of the insulating spacer 11 which concerns on 2nd Embodiment. It is a figure which shows the cross section of the insulating spacer 11 which concerns on 3rd Embodiment. It is a figure which shows the cross section of the insulating spacer 11 which concerns on 4th Embodiment. It is a figure which shows the connection structure of the turbine generator and turbine which employ | adopt a double shaft drive system. FIG. 2 is a diagram showing a connection configuration between a turbine generator 51 and a turbine 52.

Hereinafter, embodiments will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a view showing a cross section of an insulating spacer of a rotor of a rotating electrical machine according to the first embodiment.

  As shown in the figure, the rotor of the rotating electrical machine has a rotor main shaft 1 and a shaft coupling portion 2 provided for the rotor main shaft 1. On the other hand, a shaft coupling portion 4 is similarly provided for the driving machine main shaft 3 coupled to the rotor main shaft 1. In the figure, a broken line C indicates the rotation axes (center axes) of the rotor main shaft 1 and the drive machine main shaft 3.

  Each shaft joint portion 2, 4 is provided with an uneven portion for making an inlay structure (fitting structure), and a joint spigot portion 5 of the rotor main shaft 1 and a joint spigot portion of the drive machine main shaft 3, respectively. 6

  In addition, in FIG. 1, although the case where a concave shape was formed in the rotor main shaft 1 and the drive machine main shaft 3 side as an inlay structure was shown, the rotor main shaft 1 and the drive machine main shaft 3 side are formed in a convex shape. Also good.

  An insulating spacer 11 is inserted between the rotor main shaft 1 and the drive machine main shaft 3. The insulating spacer 11 has three rings (a rotating electric machine side ring 12, a driving machine side ring 13, and an intermediate ring 14) made of an iron-based material.

  The shaft coupling portion 2 of the rotor main shaft 1, the shaft coupling portion 4 of the driving machine main shaft 3, and the insulating spacer 11 are fixed to each other by fastening members (for example, bolts and nuts). As shown in FIG. 2, a fastening member hole 7 a is provided in the shaft coupling portion 2, a fastening member hole 7 b is provided in the shaft coupling portion 4, and a fastening member hole 7 b is provided in the circumferential position on the insulating spacer 11. The shaft coupling portion 2 of the rotor main shaft 1, the shaft coupling portion 4 of the driving machine main shaft 3, and the insulating spacer 11 are fixed by forming and fixing these fastening member holes 7 a to 7 c through the fastening members.

  An insulator 15 in which a glass base material is impregnated with resin is inserted between the rotating electrical machine side ring 12 and the intermediate ring 14 and between the drive machine side ring 13 and the intermediate ring 14. Here, each insulator 15 and each ring 12, 13, 14 are fixed to each other by an appropriate adhesive or the like, and the insulating spacer 11 is integrally formed.

  On both sides of the insulating spacer 11, spigot portions 16 and 17 are provided at locations corresponding to the joint spigot portions 5 and 6, respectively, and the relative radial positions of the main shafts 1 and 3 and the insulating spacer 11 are determined. Is possible.

  According to the present embodiment, the insulator 15 provided in the insulating spacer 11 can electrically insulate the rotor main shaft 1 and the drive main shaft 3 from each other. In addition, since the insulating spacer 11 has the structure of the first embodiment, the thickness of the insulator 15 can be set to a minimum thickness necessary for electrical insulation with respect to the shaft voltage. It is possible to sufficiently reduce the amount of change.

Furthermore, since the contact surfaces of the shaft coupling portions 2 and 4 and the insulating spacer 11 are respectively metal-worked surfaces, changes in the friction coefficient can be suppressed.
<Second Embodiment>
FIG. 3 is a view showing a cross section of the insulating spacer 11 according to the second embodiment.

  In the present embodiment, as shown in FIG. 3, in order to more firmly connect the components (the rotating electrical machine side ring 12, the drive machine side ring 13, the intermediate ring 14, and the insulator 15) in the insulating spacer 11. In addition to the adhesive applied to the insulator 15, each component (rotating electric machine side ring 12, driver side ring 13, intermediate ring 14, The insulator 15) is fastened.

  As in the first embodiment, each component (the rotating electrical machine side ring 12, the driving machine side ring 13, the intermediate ring 14, and the insulator 15) is fixed with an adhesive to form an integrated structure. Each component may be fastened by the fastening part 21.

Thereby, a stronger insulating spacer can be provided as compared with the insulating spacer 11 of the first embodiment.
<Third Embodiment>
FIG. 4 is a view showing a cross section of the insulating spacer 11 according to the third embodiment.

  Although the insulating spacer 11 in the first embodiment has a ring shape, in this embodiment, the insulating spacer 11 has a disk shape as shown in FIG.

By adopting such a structure, the bonding area of the insulator 15 can be increased, and the adhesion can be further improved.
<Fourth embodiment>
FIG. 5 is a view showing a cross section of the insulating spacer 11 according to the fourth embodiment.

  As shown in FIG. 5, this structure is characterized in that the outer ring dimensions of the intermediate ring 14 and the insulator 15 are larger than those of the rotating electrical machine side ring 12 and the drive machine side ring 13.

  According to the present embodiment, the electrical creepage distance between the rotating electrical machine side ring 12 and the intermediate ring 14 and between the drive machine side ring 13 and the intermediate ring 14 is increased. It is possible to reduce the possibility of energization due to foreign matter adhesion.

  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 spirit 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 ... Rotor main shaft 2 ... Shaft coupling part 3 ... Drive machine main shaft 4 ... Shaft coupling part 5 ... Joint inlay part 6 ... Joint inlay part 11 ... Insulating spacer 12 ... Rotating electrical machine side ring 13 ... Drive machine side ring 14 ... Intermediate ring DESCRIPTION OF SYMBOLS 15 ... Insulator 16, 17 ... Inlay part 51 ... Turbine generator, 52, 53 ... Turbine.

Claims (7)

Rotating electrical machine inserted between a shaft coupling part made of an iron-based material located at the end of a main shaft of a rotor of a rotating electric machine and a shaft coupling part made of an iron-based material located at an end of the main shaft of a driving machine In the rotor insulation spacer of
A rotating electrical machine side member made of an iron-based material, having an inlay portion provided corresponding to the inlay portion of the shaft coupling portion of the rotor;
An intermediate member made of an iron-based material;
Has a spigot portion provided corresponding to the fitting portions of the shaft joint hand portion of the drive motor, a drive-side member made of an iron-based material,
A first insulating member provided only between the rotating electrical machine side member and the intermediate member;
A second insulating member provided only between the driver side member and the intermediate member;
An insulating spacer for a rotor of a rotating electric machine, wherein the rotating electric machine side member, the intermediate member, the driving machine side member, the first insulating member, and the second insulating member are configured to be integrated.   The rotation according to claim 1, wherein the rotating electrical machine side member, the intermediate member, the driving machine side member, the first insulating member, and the second insulating member are fixed to each other by an adhesive so as to be integrated. Insulation spacer for electric rotor.   The rotation according to claim 1, wherein the rotating electrical machine side member, the intermediate member, the driving machine side member, the first insulating member, and the second insulating member are fastened together by a fastening member so as to be integrated. Insulation spacer for electric rotor.   The insulating spacer for a rotor of a rotating electrical machine according to claim 1, wherein the rotating electrical machine side member, the intermediate member, the driving machine side member, the first insulating member, and the second insulating member are ring-shaped.   2. The insulating spacer for a rotor of a rotating electrical machine according to claim 1, wherein the rotating electrical machine side member, the intermediate member, the drive machine side member, the first insulating member, and the second insulating member have a disk shape.   The rotor of a rotating electrical machine according to claim 1, wherein outer diameters of the intermediate member, the first insulating member, and the second insulating member are larger than outer diameters of the rotating electrical machine side member and the driving machine side member. Insulating spacer.   The insulating spacer for a rotor of a rotating electrical machine according to claim 1, wherein the first insulating member and the second insulating member are insulating members obtained by impregnating a glass base material with a resin.