RU2336962C2 - Film-lubrication bearing - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: film-lubrication bearing includes bushing-insert, which is installed in the chuck of forming roll, bushing-journal, which is hafted on roll cone neck, and thrust unit. Bushing-journal is retained against slipping on roll neck by means of key installed in keyway, which is provided on internal conical surface of bushing-journal and external conical surface of roll neck so that bridge is formed between keyway and end surface of bushing-journal from the side of thrust unit, at that bridge width makes (0.03...0.09) from minimum diameter of internal conical surface of bushing-journal.

EFFECT: increase of bearings rigidity; rolling accuracy and quality of rolled material.

5 dwg

Description

The invention relates to rolling production, and in particular to liquid friction bearings of roller bearings of rolling mills.

A well-known liquid friction bearing (analogue), including a sleeve insert installed in the cushion of the roll, a sleeve-pin mounted on the conical neck of the roll, and a thrust unit with a rolling bearing. The bushing-pin from rotation on the neck of the roll is held with a key (see Germany’s patent No. 3107296, class B21B 31/07, decl. 02.26.81, publ. 28.01.82).

The disadvantage of this analogue is the execution of the keyway in the bushing-pin through with the exit to its end surface from the thrust node. This leads to a significant reduction in stiffness and an increase in the deformation of the sleeve-journal in the radial direction. When rolling at the moment the keyway passes through the plane of the load due to an increase in the deformation of the spigot sleeve, the total deformation of the roll system and the roll gap increase, which causes the appearance of periodic transverse thickness variation and adversely affects the accuracy of rolling and the quality of the rolled metal.

The closest technical solution (prototype) is a liquid friction bearing, including an insert sleeve installed in the roll cushion, a pin sleeve mounted on the conical neck of the roll, and a thrust unit with rolling bearings (see RF patent No. 1268226, cl. B21B 31/02, decl. 11.06.85, publ. 07.11.86). From rotation on the neck of the roll neck, the pin is held by a key installed in the keyways made from the thrust unit on the conical surface of the neck of the roll and the inner conical surface of the sleeve-pin connected with it. In contrast to the analogue in the prototype, the keyway in the sleeve-pin is not through and does not go to its end surface from the side of the thrust unit. In this case, a jumper is formed between the keyway and the end surface of the spigot. The presence of a jumper increases the stiffness of the axle sleeve in the radial direction, which can reduce the overall deformation of the roll system and positively affect the accuracy of rolling. However, with an increase in the width of the jumper, the keyway approaches the end of the bushing-journal from the side of the roll barrel. Due to the decrease in the wall thickness of the pin-sleeve as the keyway approaches the roll barrel, this causes a significant decrease in the stiffness of the pin-sleeve in the radial direction, which exceeds the increase in stiffness by increasing the width of the jumper. As a result, as in the case of using an analogue, the overall deformation of the roll system increases, which reduces the accuracy of rolling and the quality of the rolled metal.

The technical result of the present invention is to improve the accuracy of rolling and the quality of the rolled metal by achieving the optimum ratio between the relative width of the bridge between the keyway and the end surface of the journal sleeve from the side of the thrust unit and the relative radial deformation of the journal journal.

The specified technical result is achieved by the fact that in the fluid friction bearing, including the insert sleeve installed in the cushion of the roll roll, the pin sleeve, mounted on the conical neck of the roll and held on it from being rotated by a key installed in the keyway, made on the inner conical surface a trunnion sleeve and the outer conical surface of the roll neck so that between the keyway and the end surface of the trunnion sleeve, a jumper is formed on the side of the thrust unit, the width of which is (0.03 ... 0.09) r minimum diameter of the inner conical surface of the trunnion sleeve.

The invention is illustrated by drawings.

Figure 1. Liquid Friction Bearing - Longitudinal Section.

Figure 2. Node A in figure 1.

Figure 3. The keyway connection of the journal sleeve and the conical neck of the roll with the fastening of the key on the inner surface of the journal sleeve parallel to the axis of the rolling roll.

Figure 4. The keyway connection of the journal sleeve and the conical neck of the roll with the fastening of the key on the inner surface of the journal sleeve parallel to the inner surface.

Figure 5. The dependence of the relative deformation of the sleeve-pins on the relative width of the lintel.

The fluid friction bearing includes an insert sleeve 1 installed in the roll roll cushion 2, a trunnion sleeve 3, mounted on the conical neck 4 of the roll, and an abutment assembly 5 with rolling bearings to absorb axial loads acting on the bearing during rolling. From rotation on the neck of the roll of the sleeve, the pin is held by a key 6 installed in the keyways made from the thrust unit on the conical surface of the neck of the roll and the internal conical surface of the sleeve of the pin connected with it.

The keyway in the spigot sleeve does not extend to its end surface from the side of the thrust assembly, and a jumper 7 of width "b" is formed between the keyway and the end surface of the spigot sleeve.

To determine the optimal width of the jumper, providing maximum rigidity and minimum deformation of the sleeve-journal in the radial direction, experimental studies were conducted. Studies have shown that the stiffness and deformation of the spigot sleeve in the radial direction under load is influenced by both the width "c" of the jumper 7 and the value of the minimum diameter d _{min of the} inner conical surface of the spigot sleeve from the side of the stop assembly. Therefore, in studies, the dependence of the relative deformation of the axle sleeve Δ on the relative width of the bridge was evaluated.

The relative deformation of the axle sleeve was determined from the ratio

where d _mino is the minimum diameter of the inner conical surface of the sleeve-journal in the absence of load;

d _minp is the minimum diameter of the inner conical surface of the journal sleeve under the action of a load.

, то есть как отношение действительной ширины перемычки к минимальному диаметру внутренней конической поверхности втулки-цапфы при отсутствии нагрузки.The relative width of the jumper was defined as the ratio

, that is, as the ratio of the actual width of the jumper to the minimum diameter of the inner conical surface of the journal sleeve in the absence of load.

The dependence of the relative deformation of the sleeve-pins on the relative width of the jumper is shown in the graph (figure 5).

от 0 до 0,03 относительная деформация втулки цапфы Δ существенно уменьшается; соответственно, увеличивается ее жесткость. В интервале значений

от 0,03 до 0,09 изменения относительной деформации Δ незначительны, после чего относительная деформация резко возрастает, а жесткость уменьшается. Таким образом, интервал значений относительной ширины

From the graph it follows that with an increase in the relative width of the jumper

from 0 to 0.03, the relative deformation of the journal sleeve Δ is significantly reduced; accordingly, its rigidity increases. In the range of values

from 0.03 to 0.09 changes in the relative deformation Δ are insignificant, after which the relative deformation increases sharply, and the stiffness decreases. Thus, the range of relative widths

It is optimal, which ensures maximum rigidity and minimal deformation of the sleeve-journal. Accordingly, the width "in" of the jumper, providing maximum rigidity and minimum deformation of the sleeve-journal, is determined from the ratio

The fastening of the dowel 6 can be performed on the neck of the roll or on the inner conical surface of the journal sleeve.

When mounting the dowels on the inner conical surface of the bushing-trunnion (Fig. 3, 4), the dowel is installed in the keyless keyway in the sleeve to increase its rigidity. The keyway on the neck of the roll from installation conditions is longer. The key can be installed both parallel to the axis of the roll (Fig. 3), and parallel to the generatrix of the inner conical surface of the sleeve-journal (Fig. 4).

The bearing operates as follows. When the neck 4 of the roll rotates together with the pin-axle 3 through the channels in the sleeve-liner 1, oil is supplied, which is entrained by the pin-axle, is fed into the working gap and forms an oil wedge between the sleeve-liner and the pin-axle, ensuring minimal friction between them.

The use of a journal sleeve with a jumper between the keyway and its end surface, the width of which is determined by relation (3), provides maximum rigidity and minimum deformation of the journal journal, accordingly reduces the overall deformation of the roller system, eliminates periodic transverse thickness variation, improves rolling accuracy and quality rolled metal.

Claims (1)

The fluid friction bearing of a rolling mill roll support, comprising a liner installed in a roll cushion, a trunnion sleeve mounted on a tapered roll neck, a thrust assembly in which the trunnion sleeve is prevented from turning on the roll neck by a key installed in a keyway, made on the inner conical surface of the journal sleeve and the outer conical surface of the journal neck with the formation of a jumper between the keyway and the end surface of the journal journal from the side of the thrust unit, characterized in that the width of the jumper is (0.03 ÷ 0.09) of the minimum diameter of the inner conical surface of the sleeve-journal.

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