JP7369661B2 - How to replace rotor shaft - Google Patents

Description

The present invention relates to a rotor shaft replacement method.

Generally, a rotating machine such as an electric motor or a generator is composed of a rotor and a stator. The rotor is directly connected to the shaft of the load machine at the shaft end of the rotor for power transmission. Usually, a coupling is used to directly connect both shaft ends of a load machine and a rotor.

The above-mentioned coupling is a mechanism that absorbs the difference in the shaft end shapes of the rotor and load machine and directly connects the shafts to each other. Torque transmission from the shaft to the coupling can be performed using a key or a key. There are transmission methods such as tightening such as shrink fitting, or transmission using a spline shaft whose shaft end is machined into a gear shape.

Transmission by tightening, such as shrink fitting, as described above, is often used to transmit large torques, and as a result, a large tightening force is inevitably required, making it necessary to remove the coupling during maintenance. In this case, the tightening force cannot be sufficiently relaxed when the coupling is removed from the shaft, and there is a risk that the end of the rotor that is directly connected to the shaft will be scratched.

In addition, since spline shafts do not involve torque transmission through tightening, the possibility of scratches caused by direct disassembly for maintenance is lower than when torque is transmitted through shrink fitting, but spline lubrication is required during operation. Therefore, shaft scratches often occur due to other causes such as poor lubrication.

If the scratches on the shaft are minor, they can be corrected by correction processing such as polishing, but if large scratches occur that cannot be corrected, the rotor becomes unusable.

The rotor of a rotating machine generally has a structure in which a hole is drilled in the center of the rotor core, which is made of laminated electromagnetic steel plates, etc., and a shaft is placed in this hole, and the torque generated in the rotor core is transferred to the shaft. In order to transmit the signal, the hole in the center of the rotor core and the shaft are fixed by shrink fitting or the like.

In addition, since the rotor core is constructed with the shaft as the core, there is a risk that the rotor core will not be able to maintain its shape as a rotor and may deform even if the shaft is removed by boring etc. There is.

Therefore, in the past, only the shaft could not be replaced, and the entire rotor had to be replaced. Since a rotor requires a lot of cost and time to manufacture, it has been desired to establish a method for replacing only the shaft.

As a prior art document regarding shaft replacement of a rotating machine, Patent Document 1 can be mentioned.

Patent Document 1 discloses an actuator structure in which a fastening screw hole is formed at the end of a rotating machine shaft, and a ball screw is assembled in which a threaded portion is screwed into the screw hole and a ball groove is formed on the outer periphery. A hollow cylindrical member that guides the fastening thread into the fastening screw hole is placed coaxially with the rotating machine shaft of the casing, and the fastening thread is inserted into the fastening thread of the rotating machine shaft along the inner surface of the hollow cylindrical member. It is stated that the shaft can be easily replaced by having a structure in which the shaft is fastened to the shaft.

Japanese Patent Application Publication No. 2007-154944

In Patent Document 1 mentioned above, a structure is adopted in which screws at both ends of a rotating machine shaft are fastened and pressed against a bearing via a flange, so that the shaft can be easily replaced by removing the flange.

However, in the case of the shaft replacement structure in Patent Document 1 mentioned above, since the shaft is mechanically pulled out together with the flange, there is a high possibility of damaging the inner peripheral side of the rotor core and peripheral parts of the shaft. In the case of rotating machines, the shaft and rotor parts are strongly fixed, so it is difficult to remove them mechanically, and it has not been possible to solve the problem of replacing only the shaft.

The present invention has been made in view of the above points, and its purpose is to provide a rotor shaft that not only does not damage the rotor core, but also allows only the shaft to be replaced without changing the structure of the rotating machine. The purpose is to provide an exchange method.

In order to achieve the above object, the rotor shaft replacement method of the present invention is a rotor shaft replacement method in which a shaft inserted into a hole provided in the center of a rotor core is replaced, the method comprising: In addition to fixing the rotor core, a through hole is provided in the shaft that reaches a key groove in which a key disposed between at least the rotor core and the shaft is installed, and the key is extracted from the through hole. , deforming the shaft so as to crush it toward the center of the shaft, then pulling out the shaft from the rotor core to take out the rotor core, and attaching the taken out rotor core to a new shaft. It is characterized by

According to the present invention, only the shaft can be replaced without damaging the rotor core, and without changing the structure of the rotating machine.

FIG. 3 is a diagram showing a state in which a shaft, which is a target of the rotor shaft replacement method of the present invention, is inserted into a hole provided in the center of the rotor core. FIG. 2 is a side view of a shaft that is a target of the rotor shaft replacement method of the present invention, showing a state in which three through holes are formed in the shaft. It is a side view which shows the end bracket arrange|positioned at the axial direction both ends of a rotor core.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a rotor shaft replacement method of the present invention will be explained based on the illustrated embodiment. In each figure, the same reference numerals are used for the same components.

Embodiment 1 of the rotor shaft replacement method of the present invention will be described using FIGS. 1, 2, and 3.

In the present invention, first, after the shaft 1 inserted into the hole provided in the center of the rotor core 2 is extracted by boring or the like, the rotor core 2 is formed in the rotor core 2 so that the rotor core 2 does not come apart. The fixing device 6 is placed using the ventilation holes etc., and the rotor core is fixed.

Note that fixing of the rotor core 2 using the fixing tool 6 is performed by attaching plates to both sides of the rotor core 2 in the axial direction and tightening bolts arranged using ventilation holes or the like.

Next, in order to make it easier to remove the shaft 1 (the shorter the shaft 1, the easier it is to remove it), cut both ends of the shaft 1 at a position close to the rotor core 2 using a machining center, and attach the rotor core 2 to the shaft 1. In order to remove the end plate keys 7 installed on the end plates 4 installed at both ends of the rotor core 2 in the axial direction from the end plates 4 at the ends of the rotor core 2, caulking is performed to fix the position of the end plates 4. 8 etc. processing is removed. Thereafter, the end plate key 7 is removed from the end plate key groove 9 of the end plate 4.

Next, three through holes are drilled in the shaft 1 (drilled with a drill or the like in the state shown in FIG. 1). That is, the shaft 1 has a first through hole 3a having the same center as the shaft 1, and a first through hole 3a that reaches a key groove 5b in which the key 5a disposed between the rotor core 2 and the shaft 1 is installed. 2 through hole 3b (a key groove 5b in which a key 5a is arranged to remove the key 5a installed between the shaft 1 and rotor core 2 in order to fix the shaft 1 and rotor core 2) a through hole that reaches the center of the shaft 1), and a third through hole provided at a position opposite to the second through hole 3b across the first through hole 3a (a position symmetrical with respect to the center of the shaft 1). The three through holes of the through hole 3c are opened.

After drilling three through holes, a first through hole 3a, a second through hole 3b, and a second through hole 3b, in the shaft 1 with a drill or the like, in order to fix the shaft 1 and the rotor core 2, 1 and the rotor core 2 is removed from the second through hole 3b formed in the shaft 1. After taking out the key 5a from the second through hole 3b, in order to pull out the shaft 1, deform the shaft 1 by crushing it toward the center of the shaft 1 (tighten it with a clamp or the like and crush it), and rotate it with the shaft 1. A shaft 1 is made movable by eliminating the interference between child cores 2. After deforming the shaft 1, the shaft 1 is pulled out from the rotor core 2, and the rotor core 2 is taken out.

After only the rotor core 2 is taken out, the rotor core 2 is attached to a new shaft by shrink fitting or the like. After the rotor core 2 is scattered on a new shaft, in order to fix the rotor core 2 and the shaft 1, end plate key grooves of the end plates 4 arranged at both ends of the rotor core 2 in the axial direction are used. Insert the end plate key 7 from 9. In order to fix the inserted end plate key 7, fix it in a position (position of crimping 10 in Fig. 3) that is different from the position before replacing the shaft 1 (position of crimping 8 in Fig. 3) (if it is fixed in the same position) , Fix the rotor core 2 and shaft 1 at different positions, as the fixation may become loose due to wear etc. caused by the first fixation).

Note that when fixing the end plate key 7, it is preferable to carry out a method such as caulking and mark the rotor core.

According to this embodiment, since the shaft 1 can be replaced without changing the structure of the rotating machine, it can also be applied to the rotor of a rotating machine with a large load transmission. Further, there is no need to manufacture additional parts, and the shaft 1 can be replaced at low cost.

Therefore, according to this embodiment, only the shaft 1 can be replaced without damaging the rotor core 2 and without changing the structure of the rotating machine.

Note that the above-described embodiments have been described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add, delete, or replace a part of the configuration of each embodiment with other configurations.

DESCRIPTION OF SYMBOLS 1... Shaft, 2... Rotor core, 3a... First through hole, 3b... Second through hole, 3c... Third through hole, 4... End plate, 5a... Key, 5b... Keyway, 6... Fixing tool, 7... End plate key, 8... Caulking before processing, 9... Groove for end plate key, 10... Caulking after processing.

Claims (8)

A rotor shaft replacement method for replacing a shaft inserted into a hole provided in the center of a rotor core, the method comprising:
The rotor core is fixed, and the shaft is provided with a through hole that reaches at least a key groove in which a key disposed between the rotor core and the shaft is installed, and the key is inserted through the through hole. extracting the shaft, deforming the shaft so as to crush it toward the center of the shaft, then pulling the shaft from the rotor core to take out the rotor core, and attaching the extracted rotor core to a new shaft. A rotor shaft replacement method characterized by: A rotor shaft replacement method according to claim 1, comprising:
A method for replacing a shaft of a rotor, characterized in that, after the shaft is removed from the rotor core, a fixture is placed in a ventilation hole formed in the rotor core to fix the rotor core. 3. The rotor shaft replacement method according to claim 1 or 2,
The shaft includes a first through hole whose center is the same as that of the shaft, and a second through hole that reaches a keyway in which a key provided between the rotor core and the shaft is installed. , three through holes are formed, a third through hole provided at a position opposite to the second through hole with the first through hole in between,
The key is removed from the second through hole, the shaft is deformed so as to be crushed toward the center of the shaft, and the shaft is pulled out from the rotor core to take out the rotor core. How to replace the rotor shaft. A rotor shaft replacement method according to claim 3, comprising:
A method for replacing a shaft of a rotor, characterized in that an end of the shaft is cut before machining the three through holes. A rotor shaft replacement method according to any one of claims 1 to 4,
After the shaft is replaced, the rotor core and the shaft are fixed by caulking, and the caulking is performed at a position different from the position of caulking performed before the shaft was replaced. A rotor shaft replacement method characterized by: A rotor shaft replacement method according to claim 5, comprising:
A shaft of a rotor, characterized in that the position of caulking made before replacing the shaft or the position of caulking done after replacing the shaft is marked on the rotor core before removing the shaft. method of exchange. A rotor shaft replacement method for replacing a shaft inserted into a hole provided in the center of a rotor core, the method comprising:
After the shaft is removed from the rotor core, a fixture is placed in a ventilation hole formed in the rotor core to fix the rotor core;
Next, both ends of the shaft are cut at positions close to the rotor core, and end plate keys installed in end plates disposed at both ends of the rotor core in the axial direction are inserted into the ends of the rotor core. In order to remove the end plate from the end plate, the caulking process for fixing the position of the end plate is removed, and then the end plate key is removed from the end plate key groove of the end plate,
Next, in the shaft, a first through hole whose center is the same as that of the shaft, and a second through hole that reaches a keyway in which a key disposed between the rotor core and the shaft is installed. and a third through hole provided at a position opposite to the second through hole across the first through hole, and the three through holes are formed in the shaft. After the formation, the key is taken out from the second through hole, and after the key is taken out, the shaft is deformed so as to be crushed toward the center of the shaft, thereby tightening the space between the shaft and the rotor core. A rotor shaft exchange characterized in that the shaft is made movable without any interference, the shaft is pulled out from the rotor core, the rotor core is taken out, and the rotor core is then attached to a new shaft. Method. 8. The rotor shaft replacement method according to claim 7,
After the rotor core is attached to a new shaft, in order to fix the rotor core and the shaft, the ends are inserted from the end plate key grooves of the end plates disposed at both axial ends of the rotor core. A rotor characterized in that a plate key is inserted, and in order to fix the inserted end plate key, fixation is performed at a position different from a position before replacement of the shaft to fix the rotor core and the shaft. How to replace the shaft.

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