JPH0247193B2 - KAIJOTOTSUKYOKUGATAKAITENSHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical background of the invention and its problems] The present invention relates to an improvement of the rotor of a salient pole type synchronous machine having a block magnetic pole structure.

A salient pole rotor with a block magnetic pole structure is widely used, for example, in self-starting synchronous motors, and is particularly suitable for synchronous motors that require heavy-load starting because the heat capacity of the magnetic pole head is large. In addition, there are two possible methods for the block magnetic pole structure: one in which the magnetic pole head and the magnetic pole body are manufactured from an integral steel ingot, and the other in which the two are manufactured separately and fastened together with tightening bolts to form the magnetic pole. , the present invention belongs to the latter. FIG. 1 shows a perspective view of a conventional magnetic pole structure, and FIG. 2 shows an axial cross-sectional view of the magnetic pole part. A magnetic pole body 2 is formed on the rotating shaft 1, and a magnetic pole head 3 is fastened to the outer peripheral surface of the magnetic pole body with bolts 4 to constitute a magnetic pole iron core. A field winding 5 is wound around this magnetic pole iron core, and these constitute a field pole. Further, a short circuit ring 6 for electrically connecting adjacent magnetic poles is fastened to both end surfaces of the magnetic pole head 3 by bolts. This is installed for the purpose of reducing the pulsating component of acceleration torque that occurs when the salient pole type synchronous motor self-starts.

In such a structure, the tightening bolt 4 is tightened by the centrifugal force acting on the magnetic pole head 3 and the field winding 5 during rotation.
However, since the magnetic pole head 3 has an overhang structure in the iron core, bending stress is generated at the same time as tensile stress in the tightening bolt on the shaft end side of the iron core. . Furthermore, this bending stress is added as a load by the short-circuiting ring 6 to the shaft end of the magnetic pole head 3, so that this shaft end becomes extremely stressed in terms of stress. In particular, the tightening bolt used at this end must be stronger than the other tightening bolts. However, even so, it may not be possible to manufacture a high-speed rotor with a large rotor diameter, for example, a rotor whose circumferential speed exceeds 100 m/sec, because of its mechanical strength, as long as the above-mentioned structure is employed.

[Purpose of the invention]

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to provide a block salient pole rotor that can increase the capacity by improving the mechanical strength of the magnetic pole head while maintaining ventilation cooling efficiency. shall be.

[Summary of the invention]

The present invention has a structure in which the magnetic pole head of a block salient pole rotor in which the body and the head of the magnetic pole core are bolted is divided into a central portion and annular end portions in the axial direction, and the outside of the both end portions. It is characterized in that the part is supported by a protrusion that stands up from the rotating shaft.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a perspective view of a block salient pole rotor exemplified by a four-pole machine according to the present invention. Similarly, FIG. 4 is a longitudinal sectional view of this rotor. In these figures, a field coil 5 is wound around a magnetic pole body 2 formed on a rotating shaft 1. This configuration is the same as the configuration according to the prior art. The feature of the present invention lies in the structure of the magnetic pole head. That is, the magnetic pole head is divided into three parts in the axial direction. The three divisions are a central portion 7 and both end portions 8. The boundary between the central part 7 and the end parts 8 is between the axially most extreme bolt that fastens the pole head to the pole body 2 and the next inwardly bolt. The cross-sectional shape of this central portion 7 is similar to that of the conventional one.

The end portion 8 has a cylindrical shape, and its outer diameter is the same as the rotor outer diameter. A smooth surface is formed on the inner circumferential side so as to correspond to the outer circumferential surface of the magnetic pole body 2 .

On the other hand, the rotating shaft 1 is provided with protrusions 9 having ventilation passages 10 in the axial direction on both shaft end sides of the magnetic poles. This protrusion may be formed integrally with the rotating shaft 1, but it may also be manufactured separately and fitted onto the rotating shaft 1 by shrink fitting or the like.

The outer circumferential surface of this protrusion 9 also has the same smooth portion as the outer circumferential surface of the magnetic pole body 2, and is adapted to come into close contact with the end portion 8 described above. The cylindrical end portion 8 is tightened and supported by the magnetic pole body portion 2 and the protrusion portion 9 by the tightening bolt 4.

In this way, the end portion 8 electrically and magnetically connects the circumferentially adjacent magnetic pole cores.

Depending on the use of the rotating electrical machine, for example, a magnetic material is used for the end portion 8 if pulsation torque (pulsating torque) is to be reduced, and a non-magnetic material is used for the end portion 8 if the leakage magnetic flux between adjacent magnetic poles is to be reduced. Such,
It can be freely selected depending on the desired characteristics.

Next, the effect will be explained. Conventionally, the shaft ends of the magnetic pole heads overhang in the axial direction, but according to the present invention, both ends are supported, so stress is reduced. Therefore, it is possible to further increase the rotor diameter and increase the capacity. Further, it is possible to prevent the shaft end from warping outward due to centrifugal force and creating a gap between the shaft end and the shaft pole body 2, thereby preventing an abnormal increase in field current and electrolytic corrosion.

In addition, the bolt at the end of the shaft used to have a diameter thicker than other bolts in order to resist strong bending moments, but it can be made thinner and unified to the same size as the other bolts, making it easier to tighten. Not only can tools be unified, but work efficiency can be improved. Further, the same jig can be used for machining the bolt holes, and since the number of cutting parts is reduced, the rigidity of the magnetic pole head 8 can be increased. Furthermore, regarding the material of the magnetic pole body 8, the use of special high-strength materials with a yield strength of 80 kg/mm ² or more is extremely limited, so the use of such difficult-to-cut materials reduces work efficiency or increases material costs. can be prevented.

Since the end portion 8 can have the same effect as the short-circuit ring in the conventional structure, the short-circuit ring that causes a load as in the conventional structure becomes unnecessary. Regarding ventilation cooling, there is a ventilation passage 1 in the protrusion 9 provided on the rotating shaft 1.
0, the ventilation cooling effect can be maintained no different from that of the conventional structure.

FIG. 5 is a perspective view of a rotor showing a modification of the present invention. In this example, the end portion 8 is divided in the circumferential direction. This dividing portion 8a is optimally located on the magnetic pole body 2 and on the same line as the magnetic pole center line. With such a structure, each magnetic pole body 2 and protrusion 9
It is possible to easily equalize the adhesion between the end portion 8 and each end portion 8, thereby facilitating workability.

〔Effect of the invention〕

As explained above, according to the present invention, the mechanical strength of the lumpy salient pole rotor can be further improved, so that it is extremely effective for increasing the speed and capacity of rotating electric machines such as synchronous motors.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional lumpy salient pole rotor, FIG. 2 is a vertical sectional view thereof, FIG. 3 is a perspective view of a lumpy salient pole rotor showing an embodiment of the present invention, and FIG. 4 is a perspective view of a conventional lumpy salient pole rotor. 5 is a longitudinal sectional view, and FIG. 5 is a perspective view of a block salient pole rotor showing a modification of the present invention. 1...Rotating shaft, 2...Magnetic pole body, 3...Magnetic pole head, 4...Bolt, 5...Field coil, 7...Center of magnetic pole head, 8...End of magnetic pole head Part, 8a...
... End division, 9... Protrusion, 10... Ventilation passage.

Claims (1)

[Claims] 1. A rotating shaft, a magnetic pole body formed on the rotating shaft, a field coil wound around the magnetic pole body, and a magnetic pole head bolted to the outer peripheral surface of the magnetic pole body. In the block salient pole rotor, the rotating shaft is provided with protrusions having ventilation passages on both shaft ends of the magnetic poles,
A block salient pole rotor characterized in that the magnetic pole head is divided in the axial direction into a central portion and both cylindrical end portions, and the outer sides of both end portions are respectively supported by the protrusion portions. . 2. Claim 1, characterized in that both end portions of the cylindrical shape are equally divided into the same number of magnetic poles in the circumferential direction, and the divided portions are disposed on the magnetic pole body. The described blocky salient pole rotor.