JP3300387B2 - Superconducting rotating electric machine rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor for a superconducting rotating electric machine.

[0002]

2. Description of the Related Art FIGS. 6 to 9 show a rotor configuration of a typical conventional superconducting rotary electric machine. In these figures, a laminated conductor (field winding) 1 is held by a winding mounting shaft 2. The wedge 3 has a function of compressing and holding the linear portion of the laminated conductor 1. The retaining ring 4 prevents liquid helium from leaking to the outside. The radiation shield 5 is provided to keep the winding attachment shaft 2 at the liquid helium temperature, and the room temperature damper 6 has a function of blocking a magnetic field and receiving torque of a rotor. An alternating current flows through the armature winding 7, and the magnetic shield 8 has a function of shielding leakage magnetic flux to the outside and increasing a main magnetic flux. Torque tube 9
Transmits torque of the rotor and reduces heat intrusion from the outside. The joint shaft 10 transmits torque, and the flexible support 11 absorbs axial deformation at the time of rotor thermal contraction. The cooling cylinder 12 turns gas helium to cool the torque tube 9. The conventional end ring 13 has a function of compressing and holding the end portion of the laminated conductor 1 by shrink fitting.

The laminated conductor 1 has an end portion at
The magnetic flux density and the electromagnetic force suddenly increase, and the reliability for quenching prevention is low with a uniform surface pressure load by the conventional end ring 13.

[0004]

In the conventional structure shown in FIGS. 8 and 9, only a uniform surface pressure can be applied to the laminated conductors of all the slots, and the rapidly increasing electromagnetic characteristic inherent in the end portion. Can not apply surface pressure load corresponding to force. Even if the laminated conductor 1 (superconducting wire) is minute, if it is deformed, it will quench (transition from the superconducting state to the normal conducting state),
It is not preferable in terms of reliability as a rotating electric machine.

The present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to prevent a quench by enabling a surface pressure load according to an electromagnetic force distribution inherent to an end portion. is there.

[0006]

In order to achieve the above object, in the present invention, an end ring is divided for each slot.

[0007]

The present invention is configured as described above, and the end ring is divided for each slot, so that the shrink fit required for the surface pressure load can be adjusted according to the local electromagnetic force. It is possible. Therefore, it is possible to set an appropriate surface pressure load corresponding to the rapidly changing electromagnetic force at the end portion of the laminated conductor, and to cope with the local electromagnetic force of each slot for the laminated conductor of any slot The surface pressure load can be improved, and the reliability for quenching prevention can be remarkably improved.

In general, the compressive preload (surface pressure) of a laminated conductor includes stress relaxation (creep deformation) after a load, a difference in heat shrinkage from a supporting structure at a cool down time, a centrifugal force at a rated rotation, an excitation. Although it changes depending on the electromagnetic force at the time, it is possible to apply an accurate compression preload in consideration of these preload changes.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external view showing an embodiment of an end ring of a rotor of a superconducting rotary electric machine according to the present invention, and FIG. 2 is a sectional view of FIG.

In the figure, an end ring 14 divided for each slot is provided on the outer periphery of a laminated conductor 1 housed in a slot of a rotor. The other configuration is the same as the conventional one, and the description is omitted.

Next, the operation and effect of the embodiment will be described. In the present embodiment, the end ring 14 is divided for each slot of the end portion, the shrink fit is adjusted according to the local electromagnetic force of the end portion, and the required surface pressure is applied. Displacement control type by adjusting shrink fitting allowance for rigidity of laminated conductor 1 (by superconducting wire, strand insulation, impregnated resin, stranded wire method, etc.) and for rigidity change due to thickness change. It is possible to apply an accurate compression preload. In addition, it is possible to sufficiently cope with stress relaxation after load application, and a change in precompression load that occurs at the time of cooling down, rated rotation, excitation, and the like.

As an example, the response to stress relaxation (creep deformation) after a compressive preload is applied to the laminated conductor 1 will be described below. As shown in FIG. 3, the split end ring 14 receives a repulsive force by compressing the laminated conductor 1, and this is simply considered as the internal pressure Pa. Where Pi: Repulsive force of the i-th slot D: End ring inner diameter (diameter) l: End ring shaft length

The repulsive force Pi varies depending on the compression load level and the like.
Shows a characteristic like curve 15 when a load is applied,
When the load is maintained, creep deformation is exhibited, and finally, the load-displacement diagram after relaxation shown in FIG. 16 is settled. Therefore, even if the compressive preload is held at the point A, the compressive preload at the point A is reduced if the load is applied to the level of the point C in anticipation of relaxation of the compressive preload. Secured.
When the required compression load (repulsion force) Pi is calculated for each slot in this manner, the divided end ring 14
Is calculated. Due to the internal pressure Pa, the split end ring 14 is displaced in the radial direction by the following amount. (At the innermost diameter) However, a: inner diameter (radius) E: longitudinal elastic modulus b: outer diameter (radius) Pa: internal pressure ν: Poisson's ratio Therefore, shrink fit δ (radius) is δ = u + max (t ₁ , t ₂ ,..., T) _n ) (3) where t _{i is} the required compression thickness of the laminated conductor in the i-th slot (corresponding to the required compression preload)

If the shrink fit calculated from the equation (3) is applied to each divided end ring 14, quenching due to stress relaxation can be prevented. The repulsive force Pi and the compressed thickness t _i are the thickness of the laminated conductor 1
Is determined by the amount of shrinkage, centrifugal force, creep deformation, electromagnetic force inherent to the end portion, and the like, and the ratio of the local electromagnetic force at the end portion is high. Therefore, by adopting the split end ring method, it is necessary to select an appropriate shrink fit allowance δ corresponding to these amounts that rapidly change along the axial direction of the winding mounting shaft 2 and apply an appropriate surface pressure. Is possible. Next, another embodiment will be described with reference to FIG.

FIG. 5 shows the split end ring 14 in the above embodiment.
Is changed in thickness. By changing the thickness of the split end ring, the surface pressure can be adjusted by the thickness in addition to the shrink fit. Accordingly, the range of the load surface pressure is wider than that of the shrink fit alone, and the reliability for preventing quench is improved accordingly.

By changing the thickness of the divided end ring, for example, the inner diameter a, the radial displacement u can be adjusted from the equation (2), and the shrink fit δ can be adjusted from the equation (3). It is. Therefore, the clearance at the time of assembling the split end ring can be controlled, and the assemblability can be greatly improved.

[0017]

As described above, in the rotor according to the present invention, since the end ring is divided, the rotor has a contraction amount, a centrifugal force, and a creep deformation amount corresponding to the contraction amount of the laminated conductor.
Appropriate surface pressure load corresponding to the electromagnetic force distribution unique to the end part is possible. Therefore, the reliability for preventing quench is remarkably improved as compared with the uniform surface pressure load by the conventional end ring structure.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram showing one embodiment of a rotor of a superconducting rotary electric machine according to the present invention;

FIG. 2 is a sectional view of an end ring portion in FIG. 1;

FIG. 3 is a schematic diagram for explaining a state in which an end ring receives an internal pressure due to a repulsive force of a laminated conductor.

FIG. 4 is a load-displacement (thickness) diagram when a compressive load is applied to a laminated conductor.

FIG. 5 is a main part configuration diagram showing another embodiment of the present invention.

FIG. 6 is a structural diagram of a typical conventional superconducting rotating electric machine.

FIG. 7 is a longitudinal sectional view of an end ring portion including the laminated conductor of FIG. 6;

FIG. 8 is a configuration diagram of a main part of an end ring portion of a conventional rotor.

FIG. 9 is a cross-sectional view of an end ring portion including the laminated conductor of FIG. 8;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laminated conductor 2 ... Winding mounting shaft 3 ... Wedge 4 ... Retaining ring 5 ... Radiation shield 6 ... Room temperature damper 7 ... Armature winding 8 ... Magnetic shield 9 ... Torque tube 10 ... Joint shaft 11 ... Flexible support 12 ... Cooling Cylinder 13 ... Conventional end ring 14 ... Split end ring 15 ... Load-displacement diagram under load 16 ... Load-displacement diagram after relaxation

Claims (1)

(57) [Claims] In a rotor of a superconducting rotating electrical machine in which a laminated conductor is accommodated in a plurality of slots provided on a winding attachment shaft and an end ring is fitted around the laminated conductor ,
The stacked conductors accommodated in the respective slots formed in the circumferential direction.
The body is held by a ring divided in the axial direction of the winding attachment shaft.
The rotor of the superconducting rotating electrical machine, characterized in that lifting the.