JPH0220858B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an oil film bearing that can be mainly applied to a bearing for a back-up roll for a rolling mill.

(Prior art) Conventional rolling mill roll oil film bearings (hereinafter referred to as bearings) are usually cylindrical shell 04 lined with bearing material such as white metal, as shown in Fig. 3.
It consists of a bearing box 03 (hereinafter referred to as a chock) with a bearing box inside, and a sleeve 02 attached to the outer periphery of a roll neck 01. As a result, the roll 01 is rotationally supported through the sleeve 02 without contacting the surface of the shell 04.

In addition, the sleeve 02 and the roll neck 01 are fitted in a tapered fit with a gentle interference fit in order to facilitate attachment and detachment when the rolls are reassembled. The key 011 for the sleeve 02 is buried, but the key groove on the sleeve 02 side is longer than the key length and runs parallel to the axis, as a result,
There are gaps a and b between the sleeve 02 and the roll neck 01 and between the sleeve 02 and the back of the key 011, respectively.
and c are usually present.

However, in recent years, rolling mills equipped with such bearings,
For example, the requirements for thickness accuracy of plate materials rolled by hot and cold strip mills are becoming more and more severe, and various measures have been taken to meet this requirement. , b, and c, the sleeve 02 undergoes elastic deformation due to the rolling load, and along with this, gaps are created due to wear, settling, etc. of each member 01, 02, 011 in the keyway portion, It is known that this has an adverse effect on the thickness accuracy of rolled plate materials.

As a countermeasure to this problem, the present applicant previously proposed an oil film bearing shown in Utility Model Application No. 112635/1982. This bearing has a sleeve 2 as shown in FIG.
High pressure oil is supplied from oil holes 10 and 11 to the oil groove 12 provided in the tapered neck portion joint surface 1a of the roll shaft 1, and the sleeve 2 is expanded and press-fitted into the roll neck 1.
By providing a large interference between both members 1 and 2, a strong interference fit is formed, and the bearing has a completely keyless structure.

However, in the bearings used in existing rolling mills, the fitting taper of the sleeve 2 is generally set to a relatively large value of 1/5.65 in order to facilitate roll rearrangement work. Therefore, when the keyless bearing is used as a roll bearing of a rolling mill having such a large taper, it is necessary to provide the sleeve 2 with a large interference, and therefore, the sleeve and the member 5 related to preventing the sleeve from coming off,
It was necessary to increase the strength and rigidity of 7 grade, which was uneconomical in terms of equipment cost.

In addition, in the event that a bearing seizure occurs during rolling, the bearing can be reused by remetalling the shell 4, but the sleeve 2 can be (outer periphery) needs to be overlaid and then ground. however,
This process often causes thermal deformation of the inner diameter of the sleeve, making it extremely difficult to maintain the desired taper fit, resulting in an uneconomical problem in which the sleeve has to be discarded in many cases. It was hot.

(Problems to be Solved by the Invention) The present invention attempts to solve the above-mentioned problems such as the uneconomical nature of conventional bearings, and is applicable to economical, especially existing roll bearings for rolling mills. The purpose of this invention is to provide an oil film bearing.

(Means for Solving the Problems) Therefore, the present invention includes: a shell housed in a bearing box; a sleeve fitted onto the roll neck portion of a roll shaft so as to form a journal in pairs with the shell; In an oil film bearing comprising a sleeve tightening device that presses the sleeve against the roll neck part, an intermediate bushing whose outer diameter has a smaller taper than the roll neck part is fitted into the roll neck part, and the outer periphery of the intermediate bushing is fitted onto the roll neck part. It has a structure in which the sleeve is fitted and a groove for supplying fluid pressure to inflate the sleeve is provided on the fitting surface between the sleeve and the intermediate bushing, and this is a means for solving the problem. It is something.

(Function) Now, in the above configuration, pressurized oil is supplied from the oil supply port to the joint surface of the sleeve and the intermediate bushing, and with the interference of the sleeve released, the pressure of the same pressurized oil is reduced, and the sleeve is pulled out from the roll neck portion. Similarly, pressurized oil is supplied to the joint surface of the sleeve and intermediate bushing, the sleeve is pushed into the joint surface to a predetermined tightness position, the oil pressure is reduced with the nut tightened, and then the sleeve tightening device is connected to the roll axis. sticks to.

(Example) Examples of the present invention will be described below with reference to the drawings.
In this embodiment, the same members as those in the conventional device are denoted by the same reference numerals, and detailed explanation thereof will be omitted. Now, FIGS. 1 and 2 are longitudinal cross-sectional views of the anti-thrust receiving side of a roll according to one embodiment of the present invention, and are taken in the direction of arrow A in FIG. 1.

In the figure, 13 is a roll neck, and an intermediate bushing 14 is attached to the tapered part 1a of the roll neck.
are press-fitted and tightly fixed, for example, by shrink fitting, and at the same time, on the outer circumferential surface 14a of the intermediate bushing,
A taper smaller than the taper 1a of the roll neck is formed, and a sleeve 15 is removably press-fitted by means to be described later so as to form a journal on the outer periphery of the bush 14 to form a pair with the shell 4. Note that the intermediate bushing 14 is fitted in advance to all the rolls including the spare roll.

Next, a spiral or mutually communicating annular groove 16 (in the illustrated case, a spiral groove ), which communicate with the holes 17 and 18 penetrating the joint surface 14a from the end surface of the roll shaft 1, and by supplying high pressure oil from the oil supply port 19 by a hydraulic device (not shown), for example, the sleeve 15 can be expanded. Do as you like.

Here, the wall thicknesses of the intermediate bush 14 and the sleeve 15 are appropriately determined so that the outer diameter of the sleeve 15 is equal to the outer diameter of a roll bearing sleeve of conventional structure (sleeve 02 in FIG. 3).

On the other hand, a plurality of protruding members 21 are removably engaged with the annular groove 20 at the end of the roll shaft 1 by means described later.
is provided on the inner periphery, and a threaded portion 2 is provided on the outer periphery of the end.
2, an annular member 24 having a piston 23 projecting thereon is attached to the outer periphery of the central portion thereof, and a ring-shaped cylinder 25 is slidably fitted thereinto to form a cylinder chamber 26. Furthermore, the annular member 2
4 is provided with a working fluid supply hole 27 such as oil that communicates with the cylinder chamber 26 as shown in the figure.

Further, the intermediate bush 14 and the sleeve 15 are held in an interference fit with the roll neck 13 via a sleeve tightening device 30 consisting of an annular retainer 28, a cylinder 25, a nut 29, and an annular member 24.

On the other hand, the annular groove 20 at the end of the roll shaft communicates with an axial longitudinal groove 31 penetrating the end surface of the shaft as shown in FIG. 2, and the protruding member 21 of the annular member can freely slide along the groove 31. They are arranged at equal pitches to each other. Therefore, the annular member 2 is inserted through the nut 29.
4 by one pitch, the protruding member 21 is aligned with the vertical groove 3.
1, the nut 29 and cylinder 25 can be integrally attached to and detached from the roll shaft.
Note that 32 and 33 are stoppers and mounting bolts for preventing rotation of the nut 29, 34 is a bearing cover, and 35 is a seal ring.

Next, in a roll rearrangement of a rolling mill having an oil film bearing according to an embodiment of the present invention having the above configuration,
The procedure for attaching and detaching the sleeve 15 will be explained.

First, remove the mounting bolt 33 and stopper 32, supply appropriate pressure oil from the oil supply hole 27 to the cylinder chamber 26, reduce the tightening force between the nut 29 and the cylinder 25, and then turn the nut to tighten the cylinder 25 and the nut 29. In addition to providing a slight gap between both members,
From the oil filler port 19 to the sleeve 15 and intermediate bush 14
Pressure oil is supplied to the joint surface 14a with the sleeve, and with the sleeve tightening margin released, both oil pressures are reduced while appropriately adjusting the oil pressure in the hydraulic cylinder chamber 26.

Next, the sleeve tightening device 30 is inserted through the nut 29.
After rotating the annular member 24 and the cylinder 25 and aligning the protrusion 21 of the annular member 24 with the longitudinal groove 31 of the roll shaft, the sleeve 15 can be extracted from the roll neck portion 13 according to a conventionally known procedure.

In addition, the sleeve 15 can be attached to the roll neck by the reverse procedure of the above steps.
0 is fitted and locked onto the end of the roll shaft, pressure oil is supplied to the joint surface 14a of the sleeve 15 and the intermediate bush 14, the sleeve is expanded by a set tightening margin, and pressure oil is supplied to the cylinder chamber 26. , the sleeve 15 is attached to the joint surface 1 via the sleeve tightening device 30.
After pushing the nut 29 into the cylinder 25 to a predetermined tightening margin position with respect to the nut 29, the two hydraulic pressures are reduced. Then stopper 32
This fixes the sleeve tightening device 30 to the roll shaft. This completes the work of attaching and detaching the sleeve 15.

(Effects of the Invention) As described above in detail, the present invention is constructed so that the taper for attaching the sleeve to the roll neck can be made much looser than that of sleeves of conventional structure, and the sleeve pushing force can be reduced. It is small, and the structure of each member of the tightening device is compact, reducing equipment costs. In addition, since the wall thickness of the sleeve can be made thinner, it is lighter in weight, which not only greatly reduces maintenance costs associated with replacing sleeves due to bearing burnout accidents, but it also makes it possible to significantly reduce the maintenance costs associated with replacing sleeves due to bearing burnout accidents. There are many excellent advantages, such as the fact that the complete keyless bearing of the present invention can be used very easily.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of an oil film bearing showing an embodiment of the present invention, Fig. 2 is a view taken along arrow A in Fig. 1, and Figs. 3 and 4 are side sectional views showing different conventional oil film bearings. It is. Explanation of the main parts of the diagram, 1...Roll axis, 1a...
... Tapered part, 4 ... Shell, 14 ... Intermediate bushing, 14a ... Joint surface, 15 ... Sleeve, 16
...Annular groove, 30...Sleeve tightening device.

Claims (1)

[Claims] 1 Consists of a shell housed in a bearing box, a sleeve fitted onto the roll neck of the roll shaft so as to form a journal with the shell, and a sleeve tightening device that presses the sleeve against the roll neck. In the oil film bearing, an intermediate bushing having an outer diameter taper smaller than the taper of the roll neck is fitted into the roll neck, and
Fitting the sleeve onto the outer periphery of the intermediate bushing,
An oil film bearing characterized in that a groove for supplying fluid pressure to expand the sleeve is provided on the fitting surface of the sleeve and the intermediate bush.