JPS58196345A - Rotor supporting apparatus - Google Patents

Abstract

PURPOSE:To effectively absorb vibration, allowing the variation of position of a rotary shaft which is generated during revolution of a rotor by permitting the protruded part of a rotor revolving shaft to be rotatably supported by a transfer pedestal supported on a foundation through dampers and springs. CONSTITUTION:A longitudinal shaft 19 is connected to the protruded part 9 of the rotary shaft 7 for rotors 6 and 6', and further supported by a transfer pedestal 18 through a bearing 20. Said transfer pedestal 18 is supported on a foundation 1 through compression coil springs 15 and 15a and dampers 16 and 16'. Therefore, the vibration having a low frequency which is generated from the protruded part 9 of the rotary shaft 7 is absorbed by dampers 16 and 16', when rotors 16 and 16' revolve, and the vibration having a high frequency is absorbed by the inertial force of the transfer pedestal 18. Also in the case when the supporting position for the protruded part 9 of the rotary shaft 7 is varied by the bearings 4 and 5, variation of the thickness of oil membrane, and thermal expansion during revolution, the transfer pedestal 18 can follow the above-mentioned variation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotor support device that allows for good balance adjustment when testing the rotational balance of a rotor of a rotating machine.

A rotor built into a rotating machine such as a turbine, congressor, Bonn/1 generator, or motor must be mounted on the rotating shaft in a well-balanced manner. This causes vibrations and prevents the rotating machine from performing its full function. In particular, the larger the rotor, the more important it becomes. Therefore, before installing the rotor in a rotating machine, it must be rotatably mounted on a support device, connected to a drive element, and operated at the rated speed to balance the rotor. I have to make arrangements.

To explain this balance adjustment work using a turbine rotor in which a plurality of disc-shaped single rotors are attached to the rotating shaft, as shown in Fig. 1, each is mounted on a pair of mounts 2. Both ends of a rotary shaft 7 to which a plurality of disc-shaped single rotors 6 are attached are rotatably supported via bearings 4.5t, and one end of this rotary shaft 7 is connected to a drive phase motor 8. Therefore, the drive phase motor 8k (therefore, the rotor 61i is operated at the rated rotational speed) and the balance of each individual rotor is adjusted.

However, in general, as shown in FIG. 1, the rotor 6
・In order to reduce the deflection of the bearing 4.5, the single rotor 6
Since the other end of the rotating shaft 7 is supported as close as possible to the bearing 5, the other end of the rotating shaft 7 protrudes from the bearing 5, and as a result, this protruding part 9 vibrates during rotation, causing a problem in the balance adjustment work. In particular, the longer the protruding portion 9 is, the more severe this phenomenon becomes. Therefore, as a countermeasure for this problem, conventionally, as shown in FIG. was. However, this device has a solid structure in which the pedestal 1o is fixed to the foundation IK, so
The vibrations of the protruding portion 9 can be adequately dealt with and suppressed! However, on the other hand, the rotating shaft 7 is caused by the difference in the thickness of the oil film between the bearings 4, 5 and 11 due to the difference in load, and the difference in thermal expansion between the bearings 4.5 and 11 due to the difference in load. It is not possible to cope with positional fluctuations KFi in which the supporting positions of the respective parts change from their initial set positions.

As a result, each bearing 4, 5. The way the load is applied to jl may become uneven than the initial setting, and unreasonable force may be applied to the rotor 6'', or the protruding portion 9 of ij#i may rise above the bearing 11, making it impossible to obtain support. Furthermore, as the balance adjustment work progresses over time, the degree of thermal strain in the bearings 4.5 and 11 changes, so the support state changes, and the relationship between the rotational speed of the rotor 6 and the amplitude of the vibration of the protruding portion 9 changes. There is a drawback that when the adjustment is repeated, the value changes and reproducibility cannot be obtained.

The measurement result of the relationship between the rotation speed and the amplitude is as shown in FIG.
It can be seen that the amplitude of the protruding part 9 increases significantly near pm, creating a dangerous situation, and as mentioned above, when the KFi protruding part 9t is supported by the frame 10, the amplitude decreases greatly, but it is indicated by @ in the figure. Thus, it can be seen that if measurements are taken twice after a certain period of time, the results will be different each time, and reproducibility cannot be obtained.

Therefore, the present invention eliminates the above-mentioned drawbacks, and provides a rotor support device that can prevent the vibration of the protruding portion 9 and can follow the positional fluctuation of the rotating shaft 71 due to changes in the state of the bearings 4, 5, 11, etc. The purpose is to

In order to achieve this object, the present invention has a structure including a pair of pedestals on which a rotor to be balanced is rotatably and removably attached and fixed to a foundation, and one end of the rotor protrudes from the pedestal. a movable pedestal that rotatably and removably supports a protruding portion of a rotating shaft; It consists of a spring that elastically supports the pedestal, and a damper that is provided between the movable pedestal and the foundation and absorbs vibrations of the protruding portion due to rotation of the rotor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotor support device according to the present invention will be described in detail below based on an embodiment shown in the drawings. Note that the same reference numerals as those used in the conventional apparatus described above will be used to omit the explanation, and only the different parts will be explained. As shown in Figure 4, which shows the main example from the front, and the A-A cross section of it [Figure 5 (A) and Figure 5 0, viewed from the right side] , a pair of foundation IK fixed plates 13. iaa are respectively attached via surface plates 14 and 14at, and the upper ends of these fixed plates 13 and 13aKFi, one pair of compression coil springs 15 and 15a, and dampers i 6m 16g are connected.

Further, both ends 17 and 171 of the bottom face are respectively connected to the fixed plate 13.
, 13a, both ends of the bottom surface of the movable frame 18, 1
The upper ends of the compression coil springs ts, tsa and the dampers 16, 16a are connected to 7.17a, and the upper end KFi of the movable frame 18 is connected to the rotating shaft 70t protruding 59 to which the single rotor 6 is fixed. The connecting shaft 19 is the bearing 2.
It is rotatably attached via 0.

Therefore, in the low rotational speed range when the rotational speed of the rotor 6' is increased by the drive motor 8, the low frequency vibrations generated from the protruding portion 9 are absorbed by the damper 16.16a.

In the high speed range, high frequency vibrations generated from the protruding portion 9 are absorbed by the inertial force of the movable frame 18.

This is clear based on the results shown in FIG. In the case of the present invention, the relationship between the rotational speed of the rotating shaft 9 and the joint shaft 19 and the apparent rigidity of the movable frame 18 is as shown by ■,
The higher the rotation speed, the stronger the apparent rigidity becomes. Also, for reference, the conventional mount l.

In the case where the basic IK is fixed, the apparent rigidity is strong in the low speed range, but becomes weaker as the speed increases. In addition, if the support positions of the N rotating shaft 9 and joint shaft 19 change due to changes in the thickness of the oil film on the bearings 4.5 and 20 during rotation or thermal expansion, the movable frame 18 can follow the changes by the springs 15 and 15a. It's becoming a trap. As a result, the force (internal pressure) supporting the protrusion N19' of the bearing 20 is always kept constant. In addition, as shown by θ in FIG. 3, in this device, even if the rotational speed increases, the vibration of the protruding portion 9 remains almost the same as in the case of the conventional case (■, @
) It can be seen that L is significantly improved compared to K.

Incidentally, it is preferable that the movable frame 18 has a large inertial mass and a large volume so as to be able to cope with vibrations of the protruding portion 9. In addition, the number and the number of dampers 16.16m in the compression coil springs 15.15a are not limited to those shown in the above-described embodiment, and they may be arranged one by one or in plurality directly below the mount 18. It is also possible to hang the IP from above.

As explained above, the present invention has the following advantages:
A damper is rotatably supported by a movable pedestal and is provided between the movable pedestal and the foundation for absorbing vibrations of the protruding portion generated during rotation of the rotor;
Since a spring is installed to elastically support the movable platform by expanding and contracting in accordance with the positional changes of the rotating shaft, low-frequency vibrations in the low rotational speed range are absorbed by the damper, and high-frequency vibrations in the high rotational speed machine are absorbed by the damper. The vibrations are mainly absorbed by the movable frame, which has a large inertial mass and a large volume, and furthermore, the movable frame or the spring K can follow the positional fluctuation of the N rotation axis caused by changes in the state of the bearing. As a result, when adjusting the balance by rotating the rotor, the work can be done extremely easily and quickly without being affected by the vibrations of the protruding portion.

[Brief explanation of drawings]

In Figures 1 and 2, the conventional rotor support device is on the right.
Top view, $5 Figure @ is a sectional view taken along the A-A arrow in Figure 5 0), No. 3
The figure is a diagram comparing the relationship between the rotational speed of the rotary shaft and the amplitude of vibration of the protruding portion in a conventional device, a heavy equipment device, and the present device. In the drawing, 16 foundations, 2.3# mount, 4.5#'im cost, 6tj single rotor, 5lit rotor, 7 is 1 rotation axis, sFi drive motor, 9 is protruding part, 1oti mount, 11# i bearing, 15.15M#'i spring, 16.16aili damper, 18 is moving frame, 20#i bearing. Patent applicant: Mitsubishi Heavy Industries, Ltd., agent, patent attorney, Shibu Mitsuishi (and one other person)

Claims (1)

[Claims] A rotor to be balanced is attached to a drive unit in a rotatable and removable manner, and a pair of pedestals are fixed to a foundation, and a protruding portion of the rotating shaft of the rotor, one end of which protrudes from the pedestal, is rotatable and detachable. a movable pedestal to support; a spring provided at a connection between the movable pedestal and the foundation and expands and contracts in accordance with positional changes of the rotating shaft with respect to the foundation to elastically support the movable pedestal; the movable pedestal and the foundation; A rotor support device comprising: a damper provided between the rotor and the damper for absorbing vibrations of the protruding portion as the rotor rotates.