RU2217252C2 - Sleeve-insert of liquid friction bearing assembly of support unit of rolling roll and method for making it - Google Patents

Abstract

FIELD: rolled stock production, namely constructions of hydrodynamic supports of rolling rolls. SUBSTANCE: sleeve-insert of liquid friction bearing has inner surface with two oil supply pockets; said surface is elliptical; large axis of ellipse is parallel relative to said oil supply pockets. Method for making sleeve-insert comprises steps of boring inner surface, centrifugal casting of babbitt; after babbitt casting deforming sleeve-insert along its outer surface in direction towards axis parallel relative oil supply pockets by value not exceeding elastic deformation value; boring inner working surface from one center until designed working size; releasing deformation effort. EFFECT: highly effective operation of liquid friction bearing, lowered labor consumption for making sleeve-insert. 2 cl, 4 dwg

Description

 The invention relates to rolling production, and more specifically to the design of the hydrodynamic supports of the rolling rolls.

 The insert sleeve, like the pin sleeve, is the main part of the fluid friction bearing (hydrodynamic support of the rolling roll), designed to absorb radial load.

 The insert bush is a thin-walled cylinder with a collar or other element with which it is fixed in the bearing pillow. To supply lubrication to the friction zone, the inner surface of the liner is equipped with oil pockets.

 Known liner bearing fluid friction, having three equal working surfaces, separated by oil pockets of small length along an arc (ed. Certificate. USSR 710695, 21 V 31/00, decl. 04.03.76, publ. 25.01.80) .

 In the manufacture of this insert liner, the bore of the inner work surfaces is produced from one center.

 The disadvantage of an insert bush with three working zones is that the oil wedge formed during operation does not provide the necessary bearing capacity at low rolling speeds and, as a rule, fluid friction bearings with insert bushings with three working zones are used in high-speed working stands of high-quality and wire mills.

 As bearings on all types of rolling mills, liquid friction bearings with bushings with two working zones are used.

 Of the well-known bushings for fluid friction bearings, the closest in technical essence is the liner having an internal working surface with two oil-supply pockets and holes in them (see Toder I.A., Kudryavtsev N.A. et al. Hydrodynamic rolling supports rolls. M: Metallurgy, 1968, p. 158-163).

 The inner working surface is oval with cylindrical surfaces, with the major axis perpendicular to the oil-supply pockets.

 This design of the insert sleeve ensures trouble-free installation of the sleeve-journal in the insert sleeve and a sufficiently high load capacity of the fluid friction bearing, including at low speeds of rotation of the rolling rolls.

 The liner is made of steel and the inner surface is poured with babbit.

 The manufacturing process for the insert sleeve includes roughing the surfaces of the steel billet, boring the inner surface of the sleeve for filling with babbitt, pouring the babbitt in a centrifugal way, and boring the babbitt surface.

The inner working surface of bushings with a diameter of more than 250 mm is bored from two centers displaced along the vertical axis of the bearing relative to the center of the bush (displacement Δ), and oil pockets are bored from centers displaced horizontally by radius R (displacement Δ ₁ ).

 A disadvantage of the known design of the liner of the fluid friction bearing is that the complexity of its manufacture is much greater than in the manufacture of a cylindrical surface, since the processing of the inner surface of the sleeve is carried out from several centers.

 In addition, the accuracy of the manufacture of work surfaces to a large extent determines the ultimate load bearing capacity of the bearing. And when processing from several centers, it is much more difficult to achieve and control this accuracy and, therefore, the bearing capacity can be underestimated.

 The objective of the present invention is to develop the design of the liner and the method of its manufacture, ensuring the effective operation of the liquid friction bearing and reducing the complexity of its manufacture.

 The task is achieved by the fact that in the insert liner of the liquid friction bearing of the rolling roll support having an internal working surface with two oil-supply pockets and holes in them. according to the invention, the inner surface is elliptical, while the large axis of the ellipse is parallel to the oil supply pockets.

 In the method for manufacturing an insert sleeve, including boring the inner surface, centrifugally filling the babbit and the internal babbit surface boring, according to the invention, after filling with the babbit, the insert bush on the outer surface is deformed in the direction of the axis parallel to the oil supply pockets by an amount not exceeding the elastic deformation , bore the inner surface from one center to the working design size and then remove the deformation force.

 Such a constructive implementation of the liner of the fluid friction bearing of the support of the rolling roll allows to increase the bearing capacity, since the oil wedge bounded by cylindrical and elliptical surfaces, with the same rolling conditions, has a greater length than the wedge bounded by two cylindrical surfaces.

 To ensure a high bearing ability of the bearing, the gap between the inner surface of the bush-sleeve and the outer surface of the bush-journal should be within 0.0003-0.002 of the diameter of the bush-journal (depending on the size of the bearing, the load on the bearing and the speed of rotation of the bearing) . To ensure trouble-free mounting of the bearing sleeve-journal in the sleeve sleeve, the gap between the inner surface of the sleeve sleeve and the outer surface of the sleeve sleeve must be within 0.001-0.003 of the diameter of the sleeve sleeve (depending on the size of the bearing). Satisfying these two requirements is best done by fulfilling the inner surface of the elliptical sleeve bush.

 The proposed method of manufacturing a sleeve sleeve of a new design allows to reduce the complexity of machining the inner surface of the sleeve due to the fact that the boring is from one center.

To explain the invention, a specific embodiment of the invention is given below with reference to the accompanying drawings, in which
in FIG. 1 shows an insert sleeve for a fluid friction bearing of a roll support,
figure 2 shows the bearing of liquid friction bearings of the rolling roll,
figure 3 section aa in figure 1 at the time of deformation of the sleeve-liner on the outer surface,
in FIG. 4 - section AA in figure 1 after boring the inner surface of the liner.

 The sleeve insert 1 of the liquid friction bearing of the support of the rolling roll 2 (thin-walled steel cylinder with a shoulder) having an elliptical inner working surface with oil-supply pockets 3 and openings 4 for supply. grease, installed in the pillow 5. Inside the liner 1 with a working clearance, there is a pin 6 mounted on the roll 2. To prevent the lubricating oil from leaking out of the bearing, the front 7 and rear 8 covers with seals are used. The major axis O-O of the ellipse of the inner surface of the liner 1 is parallel to the oil-supply pockets 3.

 When the fluid friction bearing is operating, the pin-axle 6, rotating in the insert-liner 1, captures the lubricant supplied through the holes 4 into the working gap between the inner surface of the liner-1 and the outer surface of the pin-axle 6, and then passing through the gap, the lubricant enters the inoperative zone and through the ends flows into the pockets 9 and 10, located between the end of the insert sleeve 1 and the front 7 and the back 8 of the covers, and from the pockets 9 and 10 is returned to the lubrication system.

 For the manufacture of the sleeve liner 1, as a rule, use a steel forging.

 The manufacturing process of the insert sleeve 1 includes roughing of its surfaces, boring of the inner surface of the sleeve for filling with babbit and grinding of the outer cylindrical surface for grinding with the same installation, filling the babbit with a centrifugal method. After filling with babbitt, the liner is polished on the outer surface and deformed in the direction of the O-O axis parallel to the oil-supplying pockets 3 by a value of Δ not exceeding the amount of elastic deformation, for example, using a body with an internal elliptical surface. In a deformed (clamped) insert sleeve, the inner surface is bored from one center to the working design size φD. Then, the deformation force is removed and the outer surface, under the action of elastic forces, acquires a cylindrical shape again, and the inner surface becomes elliptical, the major axis of which will be equal to D + Δ.

 The proposed design of the sleeve sleeve of the fluid friction bearing and the proposed method of manufacturing it in comparison with the known ones reduce the laboriousness of manufacturing one of the main parts of the VT, so when boring the inner surface of the sleeve of the liner, depending on the size of the liquid friction bearing, it will save from 0.35 ПЖТ 275) up to 6.5 (for ПЖТ 1320) machine hours.

 The proposed design also allows you to increase the bearing capacity at low speeds compared to bushings with a cylindrical inner working surface.

Claims (2)

1. The liner of the fluid friction bearing of the support of the rolling roll having an inner working surface with two oil supply pockets and holes in them, characterized in that the internal working surface is elliptical, while the large axis of the ellipse is parallel to the oil supply pockets. 2. A method of manufacturing a sleeve-liner of a fluid friction bearing, including boring the inner surface, pouring the babbit by the centrifugal method and boring the inner babbit surface, characterized in that after filling with the babbit, the sleeve-liner on the outer surface is deformed in the direction of the axis parallel to the oil supply pockets by an amount not exceeding the value of elastic deformation, bore the inner working surface from one center to the working design elliptical size and then remove the force e strain.

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