JPS601419A - Supporting construction of rotary shaft - Google Patents

Abstract

PURPOSE:To increase a number of supporting points of a rotary shaft so as to prevent the generation of vibration due to its rotation at a high speed, by providing at least a bush in addition to bushes in both ends of a sleeve and forming a corresponding part of the rotary shaft to this additional bush in a shape of small contour. CONSTITUTION:In addition to bushes 8a, 8b in both ends of a hollow sleeve 2, another bush 14 is provided in the vicinity of the bush 8a. The bush 14 is formed in a shape and size similar to those of the other bushes 8a, 8b. While a mandrel shaft 1 forms a small contour part 1a in which a diameter of the shaft in its part corresponding to the newly provided bush 14 is decreased a little smaller. Then a clearance between the shaft and the bush 14 is increased so that the bush 14 may not function normally as a bearing. When the mandrel shaft 1 is rotated at a high speed, it is displaced rightward by a shaft length corresponding to the small contour part 1a so that the bush 14 may function also as the bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a support structure for a rotating dill+, and is capable of responding to high-speed rotation of the lOj rotating shaft by changing the support point P of the rotating shaft.

Strips in rolling lines, f-process lines, etc. (@
Figure 1 shows the structure of the reel shaft in a device (tension reel, 2-Io reel, etc.) for winding and unwinding (plates, aluminum plates, etc.).

This is because the rotating parts are the mandrel shaft 1 and the IJ-branch 2.
It is a double axis consisting of 〃=. The sleeve 2 is supported by two bearings (for example, 9 roller bearings) 4 fixed to the frame 3, and the signal from the drive gear 6 is transmitted to the gear 5 which is set or keyed on the sleeve 2. Rotationally driven by driving force.

The mandrel shaft 1 is driven from the sleeve 2 through a key 7, etc., and is driven by bushes 3a attached to both ends of the sleeve 2.
, sb, and rotate together with the sleeve 2, but have the ability to independently move in the axial direction. Mandrel axis 1η111 is beyond that! ;The segment 9 is divided into a plurality of parts in the 1n section, and the segment 9 is expanded and contracted by the rotary cylinder 10 attached to the strip 11 later.
can be loosened from the mandrel shaft II. Also, during winding the strip 110, the end of the strip 11 should be adjusted to p, and the winding of the strip 11 on the mandrel shaft 1 should be changed to fif'.
A shaft moving device 12 for moving the mandrel shaft 1 in the axial direction is attached to the rear of the mandrel shaft 1 through a 13-metal bearing. This shaft moving device 12 is immobilized by a well-known mechanism such as a hydraulic cylinder type lever or the like, which includes several bearings 13 mounted on the mandrel shaft 1.

However, in such a reel l+111 structure, the mandrel shaft 1 is a cantilever beam with a large weight at the tip, and its risk relationship is quite low, and the damping function 1 is also low, so the mandrel shaft 1 is cloaked by resonance.

The vibration of the reel shaft l becomes considerably large, making it impossible to achieve the ζ reel rotational speed that matches the increasing line speed.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a rotating shaft support device that can be supported without causing almost any vibration or the like even under tension-cooled speed rotation. 7. The gist of the present invention, which achieves all of the above objects, is that a rotating shaft inserted into a hollow sleeve is supported by bushes provided at both ends of the sleeve, and the four-wheel rotating shaft can be rotated integrally with the sleeve. In the support 4 made of bamboo, the rotary shaft and the sleeve are connected to each other in a manner such that the rotary shaft and the sleeve can be moved relative to each other in the axial direction, and at least one bushing is provided in addition to the bushings at both ends of the sleeve, and the rotary shaft corresponding to the bushing is provided. It is helpful that the diameter of the part is made slightly smaller, so that the bush comes into contact with the rotary shaft by relative movement in the axial direction between the fitting sleeve and the rotary shaft, increasing the number of support points for the rotary shaft. do.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a rotating shaft support structure according to the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 2 shows a longitudinal section of an embodiment of the present invention applied to the reel shaft shown in FIG. 1. show. Hollow sleeve 2K, in addition to the two buttons 8a and 8b, there is another button 14.
'e Install it right near the front 4nll bushing 8a. The closer the distance between the bushing 8a and the bushing 14, the better. The shape and dimensions of the bushing 14 are different from that of the other bushing 8a.
, 8b. On the other hand, mandrel If (1
11, the shaft diameter of the portion corresponding to the newly provided bushing 14 is slightly reduced to form a small diameter portion 1a.

A large gap is provided between the bushing 14 and the bushing 4 to prevent the bushing from rotating in the state shown in FIG.

Mandrel 1'! 111k When rotating at high speed, the third
As shown in the figure, the mandrel shaft 1 is moved by a shaft length corresponding to the small diameter part ]a, and the bushes 8a and 8b at both ends of the mandrel shaft 1 are moved to the rear of the mandrel shaft 1.
At the same time, the newly installed bushing 14 is also made to function as a bearing.

By the way, the critical speed (natural frequency) of a rotating shaft in the form of a cantilever beam can be calculated by replacing the mass of the overhang part (the part protruding from the support point) with a beam without mass.

Figure 4 (Natural frequency ω of simple support at two points as shown in bl)
is the Yang Yi (
Compared to the natural frequency ω8 of
It can be seen that the value decreases with v.

That is, here, E゛Young 4, nl: Z'-Bahasog 74
'! mass, tl: axial length of the overhanging part, II: second moment of area of the axis of the overhanging part, lz: 2
Axis length between point supports, ■2: Axis section between two point supports i'+In
Second moment, ω: Overhang Tm k ″1−
When the rotating shaft is supported at two points (FIG. 4(b) 6), the vibration frequency, ωR: is the case when the end of the rotating shaft is fixed.

Therefore, it can be seen that if the overhang side is supported at two nearby points, the critical speed can be increased.

The system that achieves this is shown in FIG. 3.

However, when the bearing is supported at two nearby points, totaling three points, compared to the bearing reaction force kLa when supporting at two points as shown in FIG. 5(a), as shown in FIG. 5(b) and (c)vc, Deflection δ at that point due to load Rc. Bearing C to return to zero
If this is added, the bearing reaction force becomes ≠a+it≦, resulting in a much larger load, which tends to cause problems such as insufficient bearing capacity and service life, and it is not preferable to use the bearing in this state all the time.

Therefore, the line speed is constant.

When the coil diameter is small and high speed rotation is required, such as at the beginning of winding, three-point support is used as shown in Figure 3 to avoid resonance by increasing the critical speed at which the vibration response multiplier increases. In the low speed range, the bearing reaction force is reduced by using two-point support as shown in Figure 2. Two-point support lowers the critical speed, but since it is in a low speed range, resonance can be avoided.

Figure 6 shows the relationship between the rotational speed of the mandrel shaft 1 and the vibration response magnification;

B is for two-point support, and H is for high-speed range.

L indicates a low speed range.

The mandrel shaft 10 can be easily switched from three-point support to two-point support during one revolution using the shaft moving device 12 (see FIG. 1).

As mentioned above, with this support structure, it is possible to provide a high-speed rotating reel shaft that is compatible with high-speed lines without generating vibration, without causing damage to various parts of the reel shaft, and without causing damage to the strip. Nor.

In this embodiment, one new bushing 14 is added in addition to the bushings sa and sb at both ends, but the number of newly added bushings may be one or more. Further, the present invention is not limited to the cantilever form as in the above embodiments, but also applies to a general rotating shaft, since the natural frequency is lowered by one if the number of support points is increased, so the effect is the same. Furthermore, the 5-rotation axis is fi'il fixed in the axial direction, and the sleeve is equipped with a bushing.
It may be moved in the axial direction.

As mentioned above, detailed T/C was explained based on the embodiment.

As a result, resonance can be completely avoided in the high-speed rotation range, and the vibration bar jl
) can be supported.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing the reel shaft structure, Fig. 2 is a longitudinal sectional view of an embodiment of the present invention, Fig. 3 is a longitudinal sectional view of the embodiment in a three-point support state, and Fig. 4 (al bl is an explanatory diagram of cantilever fixed support and cantilever two-point support. Figures 5 (a), (b), and (C) are explanatory diagrams showing the difference in bearing reaction force between two-point support and three-point support. , Fig. 6 is a graph showing the relationship between the rotation speed and the vibration response magnification when the rotating shaft is supported at two points and three points.In the drawing, 1 is the mandrel shaft, la is the small diameter portion, 2 is the sleeve, 4 is a bearing. 5 is a tooth. 6 is a drive gear. 7 is a key. 8a and 8b are bushes. 11 is a strip. 12 is a shaft moving device, and 14 is a new addition. Patent applicant: Mitsubishi Heavy Industries, Ltd. Former Sub-Agent Patent Attorney Ishibu (Others) Figure 5 Figure 6

Claims (1)

[Claims] A rotating shaft fully curved δ1 inserted into a hollow sleeve is supported by bushes provided at both ends of the sleeve, and the rotating shaft is coupled so as to be able to rotate together with the sleeve, and the rotating shaft and the sleeve are connected in the axial direction. In addition to the bushings at both ends of the sleeve, at least one bushing is provided, and the partial sound of the rotating shaft corresponding to the bushing is made slightly smaller in diameter, and the sleeve and the rotating shaft are arranged in an axial direction. A support structure for a rotary shaft, characterized in that the bush contacts the rotary shaft by relative movement to increase the number of support points for the rotary shaft.