JPS5939818Y2 - split rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotor of a rotating machine, and particularly to an improvement of a split rotor such as a rotor of a high-speed salient pole synchronous machine.

In general, the rotor of a salient pole type synchronous machine consists of a shaft 1, a rim 2 made of stacked thick plate rings, which is shrink-fitted to the shaft 1, and a dot-dashed line on the outer periphery of this rim. A magnetic pole 3 indicated by is attached by suitable means such as a dovetail.

However, as the rotational speed increases, the centrifugal force proportional to the square of the rotational speed becomes extremely large, and the structure in which the shaft 1 and the rim 2 are shrink-fitted cannot provide the necessary rigidity.

For this reason, conventionally, high-speed rotors have been adopted as block rotors in which a shaft and a rim are integrated, as shown in FIG.

Furthermore, due to transportation limitations, the structure is divided into a plurality of parts in the axial direction.

At this time, in many cases, the chunk-shaped core portion is divided into a plurality of pieces so that they have approximately the same weight for ease of manufacturing.

FIG. 2 shows the structure of a split rotor in the case of a three-part rotor, for example.

That is, the block core parts 6 and 7 including both end shafts and the block core part 8 disposed between them are integrally connected by a plurality of fastening bolts 9 arranged on the circumference around the rotation axis. Combined and assembled.

That is, each block core portion 6.8 has a play hole 1.
0, the screw holes 11 are arranged on the same pitch circumference, and the fastening bolt 9 is tightened with a gap 8 between it and the idle hole 10.

By the way, as shown in Fig. 3, when the rotor is rotated at high speed with the block core parts 6°8 connected by fastening bolts 9, the centrifugal force becomes several times larger than the frictional force of the bolts. The fastening bolt 9 is deformed by the centrifugal force into the shape shown by the dashed line in FIG. 3, and a large bending stress is generated in the fastening bolt 9.

The maximum value of bending stress at that time is approximated by the following equation.

Here, σ: Maximum bending stress of fastening bolt (kglcft) A:
Deflection of fastening bolt (C2F4) E: Longitudinal elastic modulus (kglcft) j! /: Length of the play hole (cm) d: Diameter of the bolt (cm) Generally speaking, the line on the visual axis of a large-capacity machine is a dog, so l in the above formula becomes larger for a large-capacity machine.On the other hand, when rotating at high speed Therefore, the fastening bolt 9 can easily bend to the gap 8 between the fastening bolt 9 and the play hole 10 due to the strong centrifugal force.

Generally, the diameter of the idle hole of the bolt is considerably larger than the diameter of the bolt to facilitate insertion of the bolt.

Therefore, a large gap exists between the bolt and the play hole.

As shown in the above equation (1), the maximum bending stress 6 generated in the fastening bolt 9 increases in proportion to the deflection A of the fastening bolt 9, so if the gap between the fastening bolt 9 and the play hole 10 is large, An extremely large bending stress is applied to the fastening bolt 9, and it is considered dangerous.

Conventionally, in order to reduce this gap, the fastening bolts were processed into reamed bolts, play holes, or recessed holes to reduce the bending stress of the fastening bolts.

However, it is extremely difficult to accurately process the positions of the reamer holes provided in the block core portion 6 and the screw holes provided in the block core portion 8, and it is also difficult to insert the reamer bolt into the reamer hole and assemble it. , the bolt cannot be inserted,
It had drawbacks such as being inserted crookedly.

An object of the present invention is to provide a rotor for a rotating machine that is strong and stable and highly reliable, eliminating the drawbacks of the prior art described above.

In order to achieve this objective, the present invention provides a portion of the longitudinal taper in the idle hole provided in the block core portion, that is, in the rotating member on one side, and in the portion of the fastening bolt disposed therein. Moreover, a tapered eccentric bushing that can fit into the taper part is inserted between the taper part and the inner wall of the play hole.

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5.

A block core portion 6 with a bolt play hole 10 and a screw hole 1
1 is connected to the blocky iron core portion 8 with fastening bolts 9, as in the conventional structure shown in FIG.

In such a structure, the bolt play hole 10 and the screw hole 1
If the pitch circle diameters 1 are the same, a large gap will be created between the fastening bolt 9 and the bolt play hole 10, as described above.

Therefore, in this embodiment, the fastening bolt 9 is tapered Itc.
After processing, a tapered eccentric bushing 13 was inserted.

With this structure, when the tapered fastening bolts 14 are connected, the tapered eccentric bushing absorbs the bending stress applied to the tapered fastening bolts 14, thereby reducing the deflection of the tapered fastening bolts 14 during rotation. Since the bending stress of the tapered bolt 14 can be significantly reduced, the rotor can be operated safely.

Further, according to this embodiment, since the diameter of the bolt play hole 10 can be made sufficiently larger than the diameter of the fastening taper bolt 14, there is an advantage that the bolt can be inserted easily.

As explained above, according to the present invention, by making the fastening bolt tapered and inserting the tapered eccentric bushing,
Since the deflection of the bolt during rotation can be reduced and the bending stress of the bolt can be reduced, it is possible to provide a rotor for a rotating machine that is stable in strength and highly reliable.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the main parts of a rotor of a general salient pole type synchronous machine, Figure 2 is a cross-sectional view of the main parts of a three-split rotor in a conventional split rotor, and Figure 3 is a conventional bolt fastening section. 4 is a detailed view of a bolt fastening portion according to an embodiment of the present invention, and FIG. 5 is a cross-sectional view taken along the line A in FIG. 4. 6.7.8...Lumpy core part, 9...Tightening bolt,
10... Bolt play hole, 13... Tapered eccentric bush shoe, 14... Fastening taper bolt.

Claims (1)

[Scope of utility model registration request] At least two rotating members disposed on the same axis are coupled and integrated by a fastening bolt, and the coupling and integration by the fastening bolt is performed by providing a threaded hole in one of the rotating members and the other rotating member. In a split type rotor in which a play hole is provided in the rotor, and the fastening bolt is screwed into a screw hole through the play hole, a part of the fastening bolt in the play hole is tapered in the longitudinal direction. A split rotor comprising: a tapered eccentric bushing that can fit into the tapered portion and inserted between the tapered portion and the inner wall of the play hole.