JPH0260455A - Superconducting shielded stator of dc machine - Google Patents

Abstract

PURPOSE:To contrive to use a magnetic flux effectively and to miniaturize and lighten an apparatus by providing refrigerant storage tank pipes within superconducting shielded projections arranged between main poles and commutating poles in the inner peripheral part of a stator core and by cooling the superconducting material through liquid nitrogen. CONSTITUTION:Shielded projections 7 are provided integrally with a stator core 2 in the inner peripheral part of said stator core 2 between main poles 4 equipped with field windings 3 and commutating poles 6 equipped with commutating-pole windings 5, and said inner peripheral part is coated with a superconducting material integrally with the fixed recesses of said shielded projections 7 to form a superconductive shielding plate 8. Refrigerant storage tank pipes 9 are provided within said superconductive shielding plate 8, and refrigerant storage tank 12a, 12b equipped with an injection valve 10 and a safety valve 11 are arranged at both ends of said pipes. Consequently, the superconducting material of said superconductive shielding plate 8 is brought to a superconductive state with no electric resistance as the stator core 2 is cooled, to maintain the complete diamagnetism reflecting an external magnetic field characteristic of a superconducting material. Thus, a leakage flux is screened completely, the effective use of a magnetic flus can be contrived, and a magnetomotive force is made small so that an apparatus can be miniaturized and lightened.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a stator for a DC machine, and particularly to a main pole.

It relates to the field winding of a commutating pole and the magnetic shielding of the commutating pole winding.

[Conventional technology]

Conventionally, magnetic shielding for fixed rotating electric machines includes magnetic shielding for the back and ends of the stator core forming the stator, as described in U.S. Pat. No. 3,772,543, for example, but for direct current The leakage magnetic flux around the salient magnetic poles of the stator, such as the machine's main magnetic pole and interpolation, was not considered.

[Problem to be solved by the invention]

Conventionally, stator magnetic shielding has been affected by leakage magnetic flux, which increases as the current in the armature winding increases due to an increase in power supply capacity, and when there is a change in current, eddy currents occur around the stator core, resulting in iron loss. was increasing. As a preventive measure, non-magnetic plates were installed on the back and ends of the stator core to create a magnetic seal, but this was not taken into consideration in DC machines, which are highly versatile as power sources for transportation equipment. As the capacity increases, the leakage magnetic flux between the magnetic poles increases, leading to problems such as an increase in power loss and an increase in size relative to the capacity.

An object of the present invention is to provide a superconducting shield stator for a DC machine that can be made smaller and lighter by shielding magnetic flux leakage between magnetic poles and effectively utilizing the magnetic flux.

[Failure to solve the problem]

``First, the field winding is placed between the magnetic poles and the commutating poles, which have field windings and commutating pole windings on the inner circumferential part of the stator core that constitutes the stator. The wire and the superconducting shield protrusion protruding to the vicinity of the inner circumferential end face of the commutator winding, or the field winding of the main pole or the circumferential part of the commutator coil of the commutator, are made of non-magnetic metal material or This is achieved by enclosing a superconducting shielding frame in which a superconducting material is embedded in an insulating material formwork, and providing a refrigerant storage tank such as liquid nitrogen in the superconducting shielding protrusion and the superconducting shielding frame, and cooling with liquid nitrogen. Ru.

[Effect]

In this way, the superconducting shielding protrusion or main pole is arranged between the main pole and the commutating pole on the inner circumference of the stator core.

The superconducting shielding frame that surrounds the interpolation is provided with a refrigerant storage tank pipe inside the shielding protrusion that fixes the superconducting material or inside the shielding frame, and the superconducting material is cooled directly or indirectly with liquid nitrogen. As a result, the superconducting material covering the shielding protrusion and the superconducting material embedded in the shielding frame enters a superconducting state with zero electrical resistance, and maintains the perfect diamagnetism that reflects external magnetic fields unique to superconducting materials. Due to this complete diamagnetism, leakage magnetic flux from the field winding and the commutator winding is completely shielded.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIGS. 1 and 2, a stator 1 is composed of a stator core 2, a main pole 4° having a field winding 3, and a commutator 6 having a commutator winding 5. A shielding protrusion 7 is provided integrally with the stator core 2 on the inner periphery of the stator core 2 between the main pole 4 and the commutator pole 6 on which the field winding 3 and the commutator winding 5 are provided. A fixed recess is provided around the protrusion 7, and the fixed recess is integrally coated with a superconducting material to form a superconducting shielding plate 8.

A refrigerant storage tank 12a is provided inside the superconducting shielding plate 8, and has an injection valve ]-0 and a safety valve 11 at both ends thereof.
, 12b are arranged. The main magnetic pole 4 of the stator 1 configured in this way. A fixed gap is obtained from the commutating pole 6, and the rotor 13
is installed.

Superconducting shielding plate 8 and refrigerant storage tank 12a configured in this way
, 12b] is the refrigerant storage tank 1.2a, 12b.
By injecting a refrigerant (for example, liquid nitrogen) into the refrigerant storage pipe 9 from b, the stator core 2 and the superconducting shielding plate 8 are cooled, and as the stator core 2 is cooled, the superconducting material of the superconducting shielding plate 8 is It becomes a superconducting state with zero electrical resistance, and maintains the perfect diamagnetism that reflects external magnetic fields, which is characteristic of superconducting materials. Due to the diamagnetic property unique to this superconducting material, leakage magnetic flux from the field winding 3 and the commutator winding 5 that enters the stator core 2 and adjacent windings is completely shielded, allowing effective use of magnetic flux. It is possible to provide an excellent superconducting shield stator for a DC machine that is effective in reducing the magnetomotive force and reducing the size and weight.

In the following embodiments, a superconducting shield coated with a superconducting material is provided on the four fixing parts 14 of the stator core 2 between the main pole 4 with the field winding 3 and the commutator 6 with the commutator winding 5. A board 8 was installed to solve the problem. But 1! - As mentioned above, the method of fixing the superconducting material to the shielding protrusion 7 having the fixing recess 14 in the stator core 2 reduces work efficiency and there is concern that rotational vibration may cause cracks and damage. . As a method to solve such problems and obtain the same effects as in the embodiment, a field winding 3. as shown in FIGS. 3 and 4 is proposed. There is a method of forming a formwork in which the refrigerant storage tank pipe 9 is embedded in the commutating pole winding 5 using a non-magnetic metal material or an insulating material, and surrounding the refrigerant storage tank pipe 9 and the formwork with a superconducting shielding frame embedded with a superconducting material. be.

31st m1. FIG. 4 shows another embodiment of the present invention.

In the embodiments shown in FIGS. 3 and 4, the circumferences of the field winding 3 of the main pole 4 and the commutator winding 5 of the commutator pole 6 supported by the stator core 2 are
A refrigerant storage tank 16 is fixed to a U-shaped metal formwork 15 made of a non-magnetic metal material with a support plate 17, and a superconducting shielding frame 19 in which a superconducting substance 18 is embedded in the metal formwork with the refrigerant storage tank 16 inside]-5 is used. It is surrounded.

With this configuration, the field winding 3 of the main pole 4 and the commutating pole 6
The leakage magnetic flux of the commutator winding 5 can be reduced by cooling the superconducting material 1-8 in the metal formwork 15 by injecting liquid nitrogen into the refrigerant storage tank 16, as in the embodiment. Since the superconducting shielding frame 19 functions as a complete magnetic shielding plate while maintaining magnetism, the field winding 3. The leakage magnetic flux of the commutator winding 5 is completely shielded and the field winding 3. Since the leakage magnetic flux of the commutator winding 5 can be used as effective magnetic flux, the magnetomotive force can be reduced and the structure can be made smaller and lighter, and the assembly work of the superconducting shielding frame] 9 can be done separately from the stator core 2. , work efficiency can be improved. Further, since the superconducting material 18 is fixed by the metal formwork 15, there is no fear of cracks entering, and a highly reliable superconducting shield stator for a DC machine can be provided.

In the above embodiments, the superconducting shield 1- for leakage magnetic flux around the main magnetic pole 4 and commutator pole 6 on the inner circumference of the stator core 2 has been described. It can be used not only as a peripheral shield, but also for preventing external induction in small motor frames in control circuit systems.

FIG. 5 shows an example of a concrete stator shield structure of such a rotating electric machine. In FIG. 5, the structure of the seal 1 on the back side of the stator of a small rotating electric machine is as follows: main magnetic pole 4. A plurality of fixing protrusions 20 are provided integrally with the stator core 2 on the back side of the stator core 2 to which the commutating pole 6 is fixed, and a fixing recess 21 is provided in the stator core 2 having the fixing protrusions 20. A superconducting frame 25 is attached to a non-magnetic metal formwork 22 with a refrigerant storage tank 23 and a superconducting substance 24 buried therein, and an injection valve 1o and a safety valve 11 are disposed on the superconducting frame 25. This is a rotating machine 26.

With this configuration, the superconducting frame 25 not only prevents leakage magnetic flux radiating from the stator core 2 to the outside, but also completely blocks the incidence of magnetic fields from the circuits and wiring cables on the outer periphery. As a result, it is possible to construct a reliable rotating electrical machine that is free from heating of the stator due to eddy currents caused by externally penetrating magnetic flux and free from uneven rotation.

Further, the present invention can be applied as a switch frame for a changeover switch in a superconducting control circuit, a superconducting power supply circuit, etc. in addition to rotating electric machines. Figure 6 shows the superconducting frame structure of the changeover switch. The changeover switch 27 connects the circuit terminal of the superconducting electronic circuit SCC to the superconducting terminal 28 and also connects the superconducting power supply circuit S to the superconducting terminal 28.
The circuit terminal of the CP is a superconducting terminal 29, and the superconducting terminal 28
．． 29 is fixed to an insulating fixed substrate 30, and its superconducting terminal 2
8.29 switching contact is superconducting contact 3↓. The insulating fixing substrate 30 to which the superconducting terminals 28 and 29 are fixed in this way has a refrigerant storage tank 34 equipped with an injection valve 32 and a safety valve 33.
is housed and fixed in a superconducting frame 37 embedded with a superconducting material 36 within a non-magnetic metal formwork 35.

In this way, superconducting electronic circuits SCC and superconducting power supply circuits SC
The fixed frame of P changeover switch is superconducting frame 37
In this case, the superconducting frame 37 completely blocks the induction signal entering from the outside periphery and the radiation magnetic field attempting to radiate to the outside. This prevents an induction signal from entering the electronic circuit from the changeover switch 27 and causing it to malfunction, making it possible to provide a highly reliable changeover switch for superconducting circuits.

Incidentally, if a normal temperature superconducting material is used, a superconducting coated stator with the superconducting material removed from only the magnetic pole fixing portion of the inner circumference of the stator core, as shown in FIGS. 7 and 8, can be considered. Main pole 4. Stator core 2 where commutating pole 6 is not attached
In this stator structure, the magnetic pole fixing portions 41 of the main pole 4 and the counter pole 6 are removed, and a superconducting seal member 81 covered with a superconducting material 48 is provided over the entire other inner peripheral surface.

In this way, the superconducting seal body 81 can be made extremely thin and lightweight, eliminating the need for fixing protrusions, fixing frames, etc., and also eliminating the need for cooling equipment, providing the same effects as in the previous embodiments.

〔Effect of the invention〕

According to the present invention, the leakage magnetic flux between the field winding of the main pole and the adjacent copole winding is completely shielded, the leakage magnetic flux can be used as effective magnetic flux, and the magnetomotive force is reduced to achieve a reduction in size and weight. It is effective.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a DC machine according to an embodiment of the present invention, FIG. 4 is a partially cutaway perspective view showing the main parts of FIG. 3, FIG. 5 is a partial sectional view of a DC machine showing a third embodiment of the present invention, and FIG. FIG. 7 is a cross-sectional view of a rotating machine showing still another embodiment of the present invention, and FIG. 8 shows only the stator core of FIG. 7. FIG. 1. Stator, 2. Stator core, 3. Field winding, 4. Main magnetic pole, 5. Commutating pole winding, 6. Commuting pole, 7. Shielding protrusion, 8. Superconducting shielding plate, 9. Refrigerant storage tank pipe.

Claims (1)

[Claims] 1. A field winding, a main pole that supports the field winding, a commutator winding, a commutator that supports the commutator winding, and the main pole and the commutator. In the stator of a DC machine, the field winding and the commutator winding are connected from the inner peripheral surface of the stator core between the main magnetic pole and the commutator pole. A superconducting shield stator for a DC machine, characterized by being provided with a superconducting shield plate that protrudes to the vicinity of the inner peripheral end. 2. In a stator for a DC machine, the stator includes a main pole that fixes a field winding, a commutator that fixes a commutator winding, and a stator core that supports the main pole and the commutator. A superconducting shield stator for a DC machine, characterized in that the outer periphery of the winding and the commutator winding is covered with a superconducting plate. 3. In claim 2, the field winding of the main pole and the commutator winding of the commutator pole are made of a superconducting material in which a superconducting material is embedded in a mold made of a metal material or an insulating material. A superconducting shield stator for a DC machine characterized by being surrounded by a shielding frame. 4. A main pole supporting the field winding, a commutating pole supporting the commutating pole winding,
In the stator of a DC machine, which is composed of a stator core that fixes the main magnetic pole and the commutative pole, the frame that houses and fixes the stator core is formed with a formwork made of a non-magnetic metal material or an insulating material, and A fixed frame for a rotating electric machine characterized by a superconducting frame in which a superconducting material is embedded in a formwork. 5. Fixing the terminals of the plurality of superconducting electronic circuits, the terminals of the superconducting power supply circuit, the sliding contacts for terminal switching, and the insulating fixing substrate that fixes the terminals of the superconducting electronic circuit and the terminals of the superconducting power supply circuit. In a changeover switch consisting of a switch frame, the switch frame is made of a non-magnetic metal material,
Alternatively, a switch frame for a changeover switch, characterized in that a cylindrical frame of an inner cylinder and an outer cylinder is formed of an insulating material, and a superconducting substance is buried between the inner cylinder and the outer cylinder to form a superconducting cylindrical frame. .