JPS5852099B2 - Balance weight of rotating body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to rotating machines, and particularly to a balance weight for a rotating body such as a steam turbine.

FIG. 1 shows the structure of a steam turbine rotor as an example of a rotating machine.

In Fig. 1, 1 indicates the entire rotor, 2 indicates the shaft,
3 is a disc that is integrated with the shaft, 4 is a blade that is embedded in the disc of 3, 5 is a coupling that is integrated with the shaft of 2, 6 is a balance weight attachment part,
1 is a bearing that supports the rotor 1.

Next, we will discuss the balancing of rotating machinery.

Due to the precision of machine tools, or after machining due to blade implantation and arrangement work, it is common for rotating bodies such as steam turbine rotors to have some unbalance component in the rotor.

One of the requirements for stable rotation of the rotor is to remove this residual unbalance component by adding a balance weight.

Therefore, the rotor requires balance weight attachment portions, and one rotor is provided with several attachment portions.

FIG. 2 shows an example of vibration mode 8 of the steam turbine rotor.

This is the so-called primary vibration mode, and in this case, one method of balancing is to attach a balance weight as shown in 9, and therefore a balance weight attachment part is provided at the center of the rotor in the axial direction.

Next, the prior art will be explained with reference to FIGS. 3 to 6.

Figures 4 and 5 show details of the balance weight attachment part.

In FIGS. 4 and 5, 2 is a shaft, 6 is a weight attachment part, 9 is a balance weight, 10 is a weight fixing screw, 11 is a trapezoidal weight attachment groove, and 12 is a weight insertion opening.

As shown in FIG. 5, the weight mounting groove 11 is provided around the entire circumference of the shaft 2, and the weight insertion holes 12 are provided at two locations around the entire circumference, and the locations are opposite to the center of the shaft 2. (shifted by 180 degrees).

Figure 6 shows Waite's closed parks.

The weight 9 has a trapezoidal shape and has a threaded hole 14 for a weight fixing screw extending from the top to the bottom of the trapezoid.

To install the weights, first insert the weight 9 into the weight insertion slot 12.
(The shape of the weight 9 prevents it from being inserted from other places), move the fixing screw 10 into the screw hole, and insert the screw 1 into the bottom of the groove 11.
Turn screw 10 until the tips of screw 0 touch.

By doing this, the tapered portion 13A of the groove 11 and the weight 9
The tapered portion 13B of the is in strong contact, and the weight 9 is in the mounting groove 1.
It will be fixed at one predetermined position.

However, in this method, if the weights 9 are currently attached to positions 9A and 9B shown in Fig. 5, and it becomes necessary to attach another weight 9 to 9C, the weights 9A or 9B will Once removed from the insertion port 12, the weight 9C is inserted into the insertion port 12, moved inside the groove 11 to a predetermined position and fixed, and then the weight 9A or 9B is reinserted through the insertion port 12 and returned to its original position. Groove up to 11
must be moved within and fixed.

As described above, the conventional technology has the disadvantage that weights cannot be immediately installed in the desired position due to the relationship between the mounting groove and the weights that have already been installed, and that it takes a great deal of time and money to install and replace the weights. The purpose of the present invention is to change the structure of the weights necessary for rotor balance, thereby making it easier to install and replace the weights.
To provide a balance weight with a structure in which the weight does not move or come off during rotor rotation.

The key point of the present invention is to make the weight a symmetrical two-part structure with a dividing surface in the shape of a slope, and to make the slope part of one weight come into contact with the slope part of the other weight, and to restrain the other weight with one weight. It was designed to do so.

Next, an embodiment of the present invention will be described with reference to FIGS. 7 to 10.

In FIGS. 7 and 8, 2 is a shaft, 6 is a weight mounting part, 11 is a mounting groove, 15A, 15B are each two-part balance weights, 14A, 14B are screw holes on weights 15A, 15B, respectively, 10A and 10B are fixing screws for fixing weights 15A and 15B to the mounting groove 11, respectively; 13A and 13B are sloped parts of the mounting groove 11;
6A.

17A is a slope portion of the weight 15A, and 16B and 17B are slope portions of the weight 15B.

Figure 9 shows a three-dimensional view of weights 15A and 15B, and
Figure 0 shows a state in which ways 15A and 15B are combined.

As shown in FIG. 9, the weights 15A and 15B have a parallelogram-like shape and a triangular shape integrated 7, and these weights 15A and 15B have the same shape.

When attaching ways l-15A and 15B to the mounting groove 11, the attachment groove 11 is trapezoidal, while the weight 15A
, 15B are parallelogram shapes, so if the top and bottom dimensions of the weights 15A, 15B are even slightly smaller than the top dimension of the mounting groove 11, the weights 15A, 15B can be attached to the mounting groove 11 from any position on the circumference of the shaft 2. Is it possible to insert it into a monkey?

The weights 15A and 15B inserted into the mounting groove 11 are the 10th weights.
Combine each other as shown.

Then, screw holes 1 for each of weights 15A and 15B.
Fixing screws 10A in 4A and 14B.

10B and turn until the tip of the screw strongly contacts the bottom of the mounting groove 11.

That is, as shown in FIG. 11, screws 10A, 10B
screw 1 until a contact pressure P is generated between the tip of the screw 1 and the bottom of the groove 11.
0A.

When turning 10B, a reaction force T is generated at the contact portion between the slope portions 13A and 13B of the groove 11 and the weights 15A and 15B, and the ways I-15A and 15B are strongly pressed against the slope portion of the groove 11.

In addition, the slope part 16A of the weight 15A and the way) 15B
The slope portion 16B also makes strong contact.

That is, the way l-15B is fixed in the groove 11 by the wedge-shaped part MLN formed by the slope part 16A of the way 15A and the slope part 13B of the groove 11.

Similarly, the weight 15A is the slope portion 17B of the weight 15B.
and the wedge-shaped part formed by the slope part 13A of the groove 11, and the way l-15A, 15
B are constrained to each other within the groove 11 and fixed within the groove 11.

Next, the effects of the present invention are as follows.

1. By dividing the weight into two parts, the weight can be installed and replaced at any location without an insertion slot, which saves time and money for balancing work.

2. The method of fixing the weights is such that the sloped part of one weight is in surface contact with the sloped part of the other weight, and the other sloped parts of the two weights are in surface contact with the sloped part of the mounting groove and are strongly pressed. Because of this, it is very firmly fixed and will not loosen during rotation.

Another advantage of the embodiment of the present invention is that the two-split balance weight is a combination of objects of the same shape, making it easy to manufacture the weight.

Next, FIGS. 12 and 13 show other embodiments of the present invention.

In this case, the weight attachment groove 18 is rectangular.

Further, the weights 19A and 19B are a combination of weights having the same shape.

The effect is the same as in the example, but in the case of the present example, the groove shape is rectangular, and the groove machining is easier than in the example.

[Brief explanation of drawings]

Figure 1 is a side view schematically showing the steam turbine rotor;
The figure is a vibration mode diagram of the rotor shown in Fig. 1, Fig. 3 is an overall view showing the details of the conventional weight attachment part, and Fig. 4 is the I-
I sectional view, FIG. 5 is an overall view showing the weight mounting position, FIG. 6 is a three-dimensional view showing the conventional weight shape, and FIG. 7 is a plan view showing details of the weight mounting part according to the first embodiment of the present invention.
Fig. 8 is a sectional view taken along the line ■-■ of the seventh prisoner, Fig. 9 is a three-dimensional view of the weight of the present invention, Fig. 10 is a three-dimensional view of the combination of the weights of Fig. 9, and Fig. 11 is a three-dimensional view of the weight of the present invention. An explanatory diagram showing a fixing method, FIG. 12 is a plan view showing another embodiment of the present invention,
FIG. 13 is a 1-1 sectional view of FIG. 12. 15A, 15B・・・Balance weight, IO
A. 10B... Fixing screw, 16A, 16B.
...Slope part, 11...Mounting groove, 19A,
19B...Balance weight, 18...
・Mounting groove.

Claims (1)

[Claims] 1. A balance weight that is installed in a predetermined position by being inserted into a mounting groove that is provided in the circumferential direction of a rotating body and whose cross-sectional shape is narrower on the opening side than the width on the bottom side. , has a shape that is divided into two parts so as to have the same shape, and a slope is provided on the dividing surface, so that the slope part of one divided weight contacts the slope part of the other weight and is assembled. The width of each divided weight is smaller than the width on the opening side of the mounting groove, and the width of the combined weight is set larger than the width on the opening side of the mounting groove. A rotating body balance weight characterized by having a means for fixing the weights in a combined state within a groove.