JPS603390Y2 - Hollow high speed rotating body - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of a hollow high-speed rotating body, and in particular aims to stabilize the rotation by preventing the shaft screwed to the end plate of the rotating body from shifting from the center of rotation. It is.

FIG. 1 shows an example of a hollow high-speed rotary body drive device, in which an upper shaft 3 and a lower shaft 4 are attached to the upper and lower end plates 9 and 11 of the rotor 1, respectively, and an upper bearing 5 and a lower It is supported by a bearing 6.

For example, an electric motor 7 provided at the end of the lower bearing 6 is used to drive the rotating body.

Next, the structure of the rotating body 1 will be described. A part of the upper end plate 9 welded to the upper end of the cylinder 8 is fitted into a positioning fitting hole 10 formed concentrically with the cylinder 8, and the upper end plate 9 is inserted through the flange 20. The shaft 3 is screwed to the upper end plate 9 with bolts 21.

Similarly, a fitting hole 12 is provided in the lower end plate 11 at the lower end of the cylinder 8.
The lower shaft 4 is screwed with a bolt 23 via the flange 22.

When a rotating body configured in this way rotates at a high circumferential speed,
The upper end plate is pulled outward by the centrifugal force between the upper end plate 9 and the cylinder 8, and the fitting hole 10 of the upper shaft 3 is deformed as shown by the dotted line in FIG.

The fitting hole 12 of the lower shaft 4 in the lower end plate 11 is also deformed in the same manner.

At this time, since the deformation of the end plate is larger than the deformation of the shaft, a gap G is created in the fitting hole between the end plate and the shaft.

The state of deformation of the upper end plate 9 and the flange 2° during high speed rotation is shown in FIG.

That is, the deformation of the upper end plate 9 is greater than the deformation of the flange 20.

The reason for this is that the upper end plate 9 receives the centrifugal force of the end plate 9 itself and the cylinder 8.

Since the amounts of deformation of the upper end plate 9 and the flange 20 are different, the bolts 21 that fasten the two are deformed as shown in FIG.

However, in reality, slippage occurs between the bolt 21 and the flange 20, and the bolt 21 tends to become straight.

At this time, one place or multiple bolts 21 in the same direction
If the tightening force of the bolts 21 is slightly larger than the others, or if the lower surface of the head of the bolt 21 bites into the surface of the flange 20, the center of the upper shaft 3 will move in the direction of these bolts.

This state is shown in FIG. In this way, the center of the upper shaft 3 deviates from the center (rotation center) of the fitting hole 10 of the upper end plate 9, and the rotating body swings around using the amount of deviation as a radius, reducing vibration resistance and reducing rotational stability. This results in deterioration of the bearings and damage to the bearings.

The present invention has been developed in view of the above circumstances, and is an attempt to eliminate the above-mentioned drawbacks by reducing the gap created at the fitting portion between the end plate and the shaft.

The details of the present invention will be explained below with reference to drawings showing an embodiment thereof. In FIG. 2, an annular groove 13 is formed inside the end plate surrounding the fitting hole 10 of the upper shaft 3 in the upper end plate 9. be.

This annular groove 13 may be formed on the outside of the upper end plate 9 as shown in FIG.

Due to the formation of such an annular groove 13, the upper end plate 9 is deformed as shown by the broken line in FIGS. 6 and 7, and the gap G in the fitting hole 10, which causes the rotating body to whirl around, becomes extremely small. can do.

The reason why the upper end plate 9 deforms as shown by the broken lines in FIGS. 6 and 7 will be described below.

In Fig. 10, a disk 3 with the same wall thickness and a center hole with the same inner diameter is shown.
The broken line shows the state of deformation caused by centrifugal force when 1 and cylinder 32 are rotated at the same speed at high speed.

As shown in FIG. 10, the amount of displacement of the inner diameter of the disk 31 is
The reason why the inner diameter displacement amount is larger than that of No. 2 is due to the effect of centrifugal force on the portion of the disk 31 that is larger than the outer diameter of the cylinder 32.

Here, FIG. 11 shows a state of deformation due to centrifugal force when the disk 33 with a flange 34, which is a combination of the disk 31 and the cylinder 32 shown in FIG. 10, is rotated at high speed at the same number of rotations.

As shown in FIG. 11, the displacement of the C portion of the collar 34 is smaller than the displacement of the A portion.

This is because the lower end B of the collar 34 is away from the disc 33 and is less susceptible to the centrifugal force of the disc 33.

The same thing can be said for the upper end plate 9 in the present invention.
As shown in FIG. 12, the upper end of the cylindrical portion 36 inside the annular groove 13 is influenced by the centrifugal force of the disk portion 35 and is displaced largely.

However, the lower end E of the cylindrical portion 36 is not easily affected by the centrifugal force of the disk portion 35 due to the presence of the annular groove 13, so that the displacement is small.

Therefore, the upper end plate 9 is deformed as shown by broken lines in FIGS. 6 and 7.

The diameter, number, position, etc. of these small holes are determined in consideration of the stress generated.

Although the upper end plate 9 of the rotating body 2 has been described above, it goes without saying that the lower end plate 11 also has a similar structure.

As is clear from the above description, the present invention has a simple structure in which an annular groove or an annular array of small holes are formed in the end plate of the rotating body surrounding a fitting hole formed in the end plate. in,
A hollow high-speed rotating body with stable rotational performance can be obtained without deterioration of vibration resistance or damage to bearings.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a general hollow high-speed rotating body drive device.
Figures 2 and 3 are enlarged views of main parts when an annular groove is provided around the fitting part between the upper shaft and the upper end plate according to the present invention, and Figures 4a and b are enlarged views of the upper shaft and the upper end plate according to the present invention. An enlarged view of the main part when a circular arrangement of small holes is provided around the fitting part with the upper end plate,
Figure 5 is an enlarged view of main parts showing the deformation of the conventional upper end plate; Figures 6 and 7 show the deformation of the upper end plate when an annular groove is provided according to the present invention. Enlarged view of main parts, No. 8
The figure is an explanatory diagram showing the state of deformation of the upper end plate and flange during high-speed rotation, and Fig. 9 shows the state in which the center of the upper shaft deviates from the center of the fitting hole of the upper end plate as a result of the deformation shown in Fig. 8. Fig. 10 is an explanatory drawing showing the state of deformation due to centrifugal force of a disk and a cylinder of the same thickness and having a center hole of the same inner diameter during high-speed rotation, and Fig. 11 is an explanatory drawing showing the state of deformation due to centrifugal force of the disk of Fig. 10 and the same cylinder. An explanatory diagram showing the state of deformation caused by centrifugal force when a flanged disk shaped like a combination of cylinders is rotated at high speed. Figure 12 shows the deformation caused by centrifugal force when the upper end plate in Figure 2 is rotated at high speed. It is an explanatory diagram showing a state. 3... Upper shaft, 4... Lower shaft, 9...
... Upper end plate, 11 ... Lower end plate, 10,
12... Fitting hole, 13... Annular groove, 1
4...Annular arrangement of small holes.

Claims (1)

[Scope of utility model registration request] In an end plate joined to the end of a cylinder, a part of which is fitted into a positioning fitting hole formed concentrically with the cylinder, and the shaft is screwed to the end plate, the fitting hole is surrounded by the end plate. A hollow high-speed rotating body characterized by forming an annular groove or a plurality of small holes arranged in an annular arrangement.