JPS6149649A - Rotor for superconducting rotary electric machine - Google Patents

Abstract

PURPOSE:To obtain a rotor for resisting a great electromagnetic force generated at the short-circut time of a generator, by a method wherein a plurality of copper rods are inserted at equal intervals through the thickness section of the cylindrical unit made of non-magnetic substance of high strength for the outer shell for a rotor and wherein the ends of the copper rods are formed to be jointed by short-circuit rings. CONSTITUTION:An outer shell 30 for a rotor provided outside the rotor for shielding magnetic flux from outside is formed with a cylindrical unit 31 made of non-magnetic substance of high strength. And a plurality of slots 32 or grooves are provided at equal intervals for the thickness section of the cylindrical unit 31 and copper rods 33 are inserted through the slots or grooves, and the both ends of each copper rod are arranged to be integrated together by short- circuit rings 34. As a result, any deformation, exfoliation, or the like is not generated also at the short-circuited time of a generator, and the reliability is heightened because an electromagnetic shield effect is applied to the squirrel- cage copper rods 34 and mechanical strength is applied to the cylindrical unit 31.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a superconducting rotor using liquid helium as a coolant, and particularly relates to an improvement in the structure of a rotor outer cylinder in this rotor. .

[Technical background of the invention 1 Already li'i! The rotor to be incorporated into a superconducting rotary type IA, such as the one before this kind of superconducting turbine power generation, is
The rotor outer cylindrical body has a shielding function against magnetic flux disturbances from the outside. This rotor outer cylinder receives a large electromagnetic force in the event of a short circuit, so it has a three-layer damper structure.

That is, this type of superconducting rotating open rotor that has already been proposed is constructed as shown in FIGS. 4 and 5. That is, reference numeral 1 denotes a rotor inner cylindrical body containing liquid helium 2 as a cooling medium in the rotor, and a room temperature damper 3a is provided on the outer periphery of the rotor inner cylindrical body 1. Reinforcement cylinder 3b reinforced from
, 3c are provided with a gap in between, and a torque tube 4a attached to one end of the rotor inner cylinder 1 is secured to a fixing bolt (not shown), for example. ) is fixed to the joint shaft 13a.

Further, the torque tube 4b attached to the other end of the rotor inner cylindrical body 1 is connected to the other joint shaft 13b via a thermal expansion/contraction member 5, such as a bellows, which absorbs thermal expansion. Further, the liquid helium 2 contained in the rotor inner cylinder 1 is supplied to the joint shaft 1'3a.
The liquid helium is supplied through a liquid helium supply pipe 6 drawn through the interior of the rotor, and the liquid helium supplied into the rotor inner cylinder 1 cools the rotor inner cylinder 1 and these vacuum chambers. After doing the work, υ is passed through the jW flow tube (not shown).
Purchases are starting to flow out.

On the other hand, in the rotor inner cylinder 1, as shown in an enlarged view in FIG. A superconducting coil 8 having a rectangular body 9 and an insulating spacer 10 is placed in the coil groove 7.
is inserted.

Further, a pair of superconducting coils 11 provided at both ends of the rotor inner cylinder 1 are fixed by a holding cylinder 12 that is strong against centrifugal force and electromagnetic force.

Both ends of the rotor outer cylindrical body 3 located outside the retaining ring 12 are fixed to the double-jointed shirts l-13a and 13b by fixing bolts (not shown).

Further, the rotor outer cylindrical body 3 also serves as a vacuum container forming a vacuum chamber, and has a damper structure capable of shielding against penetration of external alternating magnetic fields and disturbances in magnetic flux during load fluctuations. The rotor outer cylindrical body 3 has reinforcing cylindrical bodies 3b and 3c bonded or bonded to the inner and outer peripheries of a cylindrical room-temperature damper 38, as shown by the vector of stress distribution in FIG. They are integrally laminated by shrink fitting.

In particular, the normal temperature damper 3a receives a large electromagnetic force P when the generator is short-circuited.

That is, to express this mathematically, P=Pt +P2 CO32θ However, Pr is the steady pressure, and P2 is the electromagnetic force received by the room temperature damper 38 in FIG. Let the angle in the circumferential direction be θ,
It is a pressure distributed in cos 2θ.

Therefore, the normal temperature damper 38 and both reinforcing cylinders 3
The rotor outer cylindrical body 3 constituted by b and 3c deforms into an elliptical shape, and bending stress is generated which is reversed at points A and 8 shown in FIG.

This bending stress is approximately 20 to 30 Kg/mm2 for the normal temperature damper 3a, calculated using electromagnetic force based on a commercial machine, as shown in FIG. Approximately 70 to 80 lines/m are applied to the reinforcing cylinders 3b' and 3'c.
It is about m2.

Therefore, in order to withstand these maximum stresses, the room-temperature damper 38 must be made of a high-strength precipitation hardened type (7).
fM gold alloy yield stress (7V: 40 K9/mm
2'j:i degree), and each of the above-mentioned reinforcing cylinders 3b and 3c are made of high-strength non-magnetic material! l1l (yield stress σy=10
0kg, about 2 feet) is used.

Note that the wall thickness d of the normal temperature damper 38 is determined by the following formula.

However, W: 2πt, ": frequency, μ: magnetic permeability, σ: 3
Indicates the 4-electricity rate.

Therefore, the wall thickness d of the room-temperature damper 3a is approximately 25~25 mm, assuming that it cuts approximately 10H2 or more against the alternating current magnetic field.
The thickness of both reinforcing cylinders 3b and 3c is approximately 25 to 35 seconds, since the reinforcing cylinders 3b and 3c have rigidity against short circuit force.
A wall thickness of approximately 1.5 mm was selected.

As described above, the method for manufacturing the rotor outer cylinder body 3 composed of three layers is as follows: (1) In advance, 1tfl, which will become the room temperature tamper 3a, and non-magnetic plates, which will become the reinforcing cylinders 3b and 3c, are prepared. A method of stacking them, explosively bonding or gluing them, rolling them into a cylindrical shape, and joining the joining surfaces ('2J, prepare in advance one copper cylinder and two magnetic cylinders that fit into it) (3) A method is proposed in which these three cylinders are fitted and then joined together by shrink fitting or brazing after fitting to form a triple layer. has been done.

[Problems with Background Art] The rotor outer cylinder 3 described above is manufactured by bonding reinforcing cylinders 3b and 3c on the inner and outer peripheries of the normal temperature damper 3a, either singly or in combination, such as by explosion bonding, shrink fitting, or brazing. However, the reinforcing tube 3
The adhesion between b, 3c and the room temperature damper 3a is unreliable. Especially when it comes to commercial use, the length is about 6 meters, making it even more difficult to completely adhere the entire surface.

If the adhesion between the reinforcing cylinders 3t and 3c and the room-temperature damper 3a is poor, stress as shown in FIG. 7 will be applied at the time of short circuit, and the room-temperature damper 3a will be plastically deformed, losing its rotational balance and becoming unusable.

[Object of the invention] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a highly reliable superconducting rotor that can withstand the large electromagnetic force that occurs during a short circuit during power generation failure. shall be.

[Summary of the Invention] In order to achieve the above object, the present invention provides a rotor outer cylindrical body in which a plurality of holes or grooves are formed at equal intervals in the axial direction in the thick part of a cylindrical body made of a high-strength non-magnetic material. Insert a copper rod into this hole or matching groove, and attach a short hole to the end of each copper rod. This is a superconducting rotating current rotor characterized by eight rings joined together.

[Embodiments of the invention] Hereinafter, the present invention will be explained with reference to the drawings.

1 and 2 are a view of a rotor outer cylinder according to an embodiment of the present invention as viewed from an axial end and an axial cross-sectional view.

That is, the rotor outer cylindrical body 30 is made of a high-strength non-magnetic material (for example, Inconel alloy, A286, which is cold-worked and then hardened). Circular hole 3 with a predetermined cross-sectional area or more by 100 etc.
2 are formed at equal intervals, and each copper rod 33 is inserted into the hole 32, and a short hole is formed at both ends of each copper rod. The B rings 34 are joined together.

It is said that the rotor outer cylindrical body 30 should have a wall thickness of at least 8 rra when focusing on electromagnetic shielding from the outside. Therefore, when constructing a copper rod structure as described above, the cross-sectional area and number of each rod are set so that the total cross-sectional area of copper in the axial direction is the same.

For example, if the outer diameter of the conventional structural rotor outer cylinder is 800 mm, the cross-sectional area of the rotor outer cylinder is π(4002-(40
0-8)2) 19905mm2.

199 to replace this cross-sectional area with 16 pieces of copper 1133
05 ÷1 6-1 244 reward 2 (1244÷:114
15) -19,9 The diameter of one copper rod 33 is 40 m.
m or more is required. Copper W! If the number of 33 is doubled to 32, the diameter of one copper t*33 will be 28 mm or more.

According to the rotor external body 30 having the structure described above, the following effects can be obtained. Conventional rotor outer cylinders with a three-layer structure lacked reliability in terms of adhesion, but the rotor outer cylinder 30 described above has a cylindrical body 31 with a support, and the gA support 33 has the same strength. It is simply inserted into the hole 32 of the cylindrical body 31. Therefore, even if stress is applied to the cylindrical body 31 to make it into an ellipse in the case of Te or σ, there is no need to worry as long as the thickness is sufficient for strength. In addition, the copper rod 33 and the cylindrical body 3
1 has only been inserted from the beginning and is not in close contact.

Therefore, as long as the cylindrical body 31 is not deformed, the rotational balance will not be lost, there will be no fear of peeling, and the fH reliability will be higher.

FIG. 3 is a view of a rotor outer cylindrical body according to another embodiment of the present invention, viewed from the axial end. That is, when the cylindrical body 31 is long and drilling is difficult, a plurality of slit grooves 35 are machined from the inner surface of the cylindrical body 31 toward the center, and a new rectangular copper plate is formed in the slit groove 35. Insert each rod 36,
After this, in order to fix each copper rod 36, a lid 37 is attached to each
is inserted and fixed with bolts 38. In this case, unlike machining, the shape of the copper rod is not limited to a circular cross section, but various shapes such as rectangular, fan-shaped, elliptical, triangular, etc. can be used.

Note that the lid 37 is not fixed to the bolt 38.

The periphery of the lid 37 may be welded.

[Effects of the Invention] According to the present invention, a plurality of holes or grooves are formed in the thick part of the cylindrical body made of a high-strength non-magnetic material as the rotor outer cylinder body in the axial direction, and the holes or grooves are A copper rod is inserted into the matching groove, and a short ring is joined to the end of this copper rod, so unlike the conventional three-layered rotor outer cylinder, there is no risk of deformation or peeling due to large stress during short circuits. Therefore, a more reliable rotor for a superconducting rotating electric machine can be provided.

[Brief explanation of drawings]

FIGS. 1 and 2 are views of the rotor outer cylindrical body of the superconducting rotating shaft according to the present invention/JI example as seen from the axial end, and FIG. 3 is an axial cross-sectional view. FIGS. 4 and 5, which are views from the axial end of a rotor body according to another embodiment of the present invention, show the axial direction and the axial direction of the previously proposed iB lightning induction rotor. is a schematic configuration diagram seen in the right angle direction, Figure 6 is a diagram to explain the electromagnetic force received when the normal temperature damper in Figures 4 and 5 is short-circuited, and Figure 7 is B in Figure 6.
It is a stress distribution diagram at a point. 1...Liquid helium, 2...Rotor inner cylinder, 3...
・1 rotor outer cylinder, 3a... normal temperature damper, 31)・
...Reinforcement cylinder, 3C...Reinforcement cylinder, 4a, 4b...
・Torque tube, 5... Heat expandable material, 6... Supply pipe, 7... Coil groove, 8... Superconducting coil, 9...
Wedge body, 10... Insulating spacer, 11... Superconducting coil, 12... Holding cylinder, 13a. 13b... joint shaft, 30... rotor outer cylinder body,
31... Cylindrical body, 32... Hole, 33.36...m
Dedication, 34...Short case ring, 35...Slit groove, 37.
...Lid, 38...volts. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4 Figure 6

Claims (1)

[Claims] In a rotor of a superconducting rotating electric machine having a rotor outer cylinder body that shields magnetic flux from the outside, the rotor outer cylinder body has a plurality of rotor cylinders in the thick part of the cylinder made of a high-strength non-magnetic material in the axial direction. 1. A rotor for a superconducting rotating electric machine, characterized in that holes or grooves are formed at equal intervals, a copper rod is inserted into each hole or groove, and a short ring is joined to an end of the copper rod.