WO2017063948A1

WO2017063948A1 - Bearing bush

Info

Publication number: WO2017063948A1
Application number: PCT/EP2016/074005
Authority: WO
Inventors: Daniel Knie; Johannes Alken
Original assignee: Sms Group Gmbh
Priority date: 2015-10-13
Filing date: 2016-10-07
Publication date: 2017-04-20
Also published as: TW201719042A; TWI636201B; DE102015219752A1

Abstract

The invention relates to a bearing bush (100) for an insertion piece (200) for rotatably supporting a roll neck (310) of a roll in a roll stand. The bearing bush has at least one bore (110) for supplying oil to an interior (120) for receiving the roll neck, the interior being spanned by the bearing bush. To increase the load capacity of the bearing bush, or the insertion piece comprising the bearing bush, according to the invention, the bore for the oil supply is provided in only one angle at circumference range of 70° < α < 110°, preferably of 80° < α < 110°, in the rotational direction (R) of the roll (300) with respect to a half-plane on which the maximum roll force acts under loading conditions. The invention also proposes that the inner face of the bearing bush is smooth in an angle at circumference range (β) in the rotational direction of the roll with respect to the half-plane.

Description

bearing bush

The invention relates to a bearing bush for a chock, also called bearing housing, for rotatably supporting a roll neck of a roll in a rolling stand.

Such bushings are known in the art, e.g. basically known in US 3,743,367 or US 2014/0169712 A1. The bearing bushes known from the two cited publications each have two holes for a possible oil supply in the space spanned by the bearing bush interior between the bearing bush and the roll neck mounted therein, wherein only one of the two oil pockets is used as an oil supply. Due to the oil pumped into the interior, an oil film is formed between the bearing bush and the roll neck, which in particular at the beginning of a rolling process creates a separation between a rotating support roll and the stationary chock. This oil film between the rotatably mounted in the chock bearing bush and the rotating pin of the roller advantageously prevents even in the prior art, a friction. The bushings of the prior art typically have a load zone when installed. For upper backup rolls, the load zone is at the top; at lower backup rolls in a rolling stand, the load zone is directed downwards. The bushings typically have a hydrodynamic feed pocket for the oil in the region of the oil supply, which lies in the direction of rotation in front of the load zone at approximately 270 °.

In the area of the load zone, the bearing bush can suffer due to erroneous operation on its inside wear. In order not to have to recycle the worn bushing after the first period of use, the bearing bushes in the prior art with the help of a Federal located at its front side pulled out of their associated chocks, rotated 180 ° about its longitudinal axis and then reinstalled in the chock. This approach is possible because the bushings in the prior art are typically symmetrical, ie they have the inlet holes for the oil supply and the respective associated hydrodynamic oil pockets each on opposite sides of the bearing bush. During rotation about the longitudinal axis of the collar of the bearing bush remains on the same front side of the chock as before rotation. With the said rotation is achieved that the worn during the first period of use on the inside of the bearing bush is now opposite the load zone and in the region of the load zone, the inside of the bearing bush at the beginning of a second period of use is still new or not worn.

The pressure build-up in an oil film bearing in the manner described is carried out in a wedge-shaped gap, which is due to the differences in diameter between the bearing bush and rotating roller. The second, not in use oil pocket, which is arranged in 90 ° in the direction of rotation in front of the load zone prevents the bearing bushes in the prior art, a continuous pressure build-up in the wedge-shaped gap, because each located there oil pocket a bump on the inside of the wall Bearing bush represents. The same applies to other disturbances on an otherwise smooth inside of the bearing bush.

Based on this prior art, the present invention seeks to further form a known bushing and an associated chock that their carrying capacity is increased.

This object is solved by the subject matter of patent claim 1. This is characterized in that the bearing bush according to the invention at least one bore for the oil supply only in a single circumferential angle range α of 70 ° <α <1 10 °, preferably 80 ° <α <100 ° in the direction of rotation of the roller, relative to a half-plane, in which the maximum rolling force acts in the load case, having. It is also claimed that the inside of the bearing bush in a circumference to the angular range ß with 180 ° <ß <360 ° in the direction of rotation of the roller relative to the half-plane formed smooth. The term "oil" is synonymous with any coolant and / or lubricant.

In the load case, the roll neck shifts in the radial direction from the middle of the bearing bush. It then creates a crescent-shaped oil film in cross section. In the area of maximum load, the cross section of the film is minimal; In contrast, it is maximum on the opposite side. The relevant for the pressure build-up of the oil within the annular gap between the bearing bush and roll neck is located in the bearing bush according to the invention opposite to the bore for the oil supply, i. seen in an angular range of 180 ° -360 ° in the direction of rotation of the roller relative to the half-plane. The larger this angular range for the pressure build-up, the greater the bearing capacity of the bearing assembly. For the greatest possible pressure build-up, it is crucial that the surfaces delimiting the crescent-shaped annular gap for the oil, i.e., the surface of the roll neck and the inside of the bearing bush, are as smooth as possible in this area of the pressure build-up, i. The surfaces of the gap limiting elements should be as homogeneous as possible and have no unevenness, in particular no holes or oil pockets.

By further claimed feature for the bearing bush according to the invention, namely that it has a bore for the oil supply only in a single circumferential angular range, which is opposite said region for the pressure build-up, it is ensured in particular that such a bore for the oil supply not in the region of desired pressure build-up is arranged so that this area is not disturbed by a hole for oil supply. In such an inventive claimed embodiment of the bearing bush, the angular range ß for the pressure build-up then advantageously extends over an angular range of 180 °, resulting in a maximum pressure build-up and thus also to a maximum load capacity of the bearing bush.

According to a first exemplary embodiment of the invention, the bearing bush preferably has only a single hydrodynamic oil pocket in the region of the at least one bore on the wall of its interior. This feature advantageously ensures that the oil pocket is at most in the area of the bore, but not in the said area of the pressure build-up, i. in the circumferential angle range ß, may be arranged.

According to a further embodiment, it is claimed that the bearing bush should not have a collar or bead at any of its end faces, which exceeds the other outer diameter of the bearing bush in the radial direction.

Such collars are usually attached to the bushings in the prior art because they have been required for a long time to disassemble the bearing unit from the roll. Meanwhile, however, there are methods to dismantle bearing units without such bundles of rollers can.

The lack of such bundles offers the advantage that even the bearing bushes of the claimed type can be reused with an angular range α for the oil supply, if they are worn after a first period of use locally in the load zone, without first having to be reprocessed. For reuse, the bearing bushes according to the invention are removed after the first period of use from their chock and subsequently - after a rotation through 180 ° about its transverse axis Q - re-installed in the chock. Because the areas of the strongest wear on the inside of the bushing typically occur in the range of maximum load can be achieved by this described conversion measure more advantageous that after turning the bushing of the new load range is still new. Only after a second period of use, when the two opposite angular ranges have signs of wear, the bearing bush is then fed to a treatment.

Advantageously, the bearing bush is integrally formed; also this feature advantageously prevents disturbances in the surface of the inside in the area of the pressure build-up, i. in the angular range ß.

The above object of the invention is further achieved by a chock according to claim 5. The advantages of the chock correspond to the advantages mentioned above with respect to the bushing.

The invention is accompanied by two figures, wherein

1 shows a chock with a bearing bush according to the invention; and

Fig. 2 shows a cross section through the bearing bush according to the invention for an upper support roller in a roll stand in the load case.

The invention will now be described in detail in the form of embodiments with reference to said figures. In all figures, the same technical elements are designated by the same reference numerals.

1 shows a chock (200) with a bearing bush (100) according to the invention for rotatably supporting a roll neck of a roll in a roll stand. The chocks are, optionally with the rollers mounted therein, vertically movable in the uprights of the mill stand. In the chock (200) an inlet channel (210) can be seen for supplying oil through at least one bore (1 10) in the bearing bush in the interior of the bearing bush.

The oil supply holes (110) on the inside of the bushing (100) typically open in a hydrodynamic oil pocket (130), i. a planar recess in the region of the holes, as shown in Fig. 1. The bearing bush (100) has the outer diameter D. Its interior is designated by the reference numeral 120.

Fig. 2 shows a cross section through the bearing bush (100) according to the invention with a drawn cross section through the roll neck (310) of a roller (300). FIG. 2 shows the load situation for a bearing bush of an upper support roller in a roll stand; In this case, the roll neck (310) is pressed in the radial direction against the upper inside of the bushing due to the rolling force (F). The bushing (100) has at least one bore (1 10) for the oil supply, said at least one bore in a single circumferential angular range (a) of 70 ° <a <1 10 °, preferably 80 ° <a <100 ° in Direction of rotation (R) of the roller relative to a half-plane (W) is located. The half-plane (W) extends, starting from the center axis of the bearing bush, at an angular position of 0 ° in the direction of the load, as shown in FIG.

The inside of the bearing bush is formed smooth in one of the bores for the oil supply circumferential angular range (ß) with 180 ° <ß <360 ° in the direction of rotation of the roller relative to the half-plane (W). That is, in particular is located in this area on the inside of the bushing no inhomogeneities or bumps, such as holes or recesses, which to turbulence in the oil flow and thus to a deterioration of the pressure buildup and thus to a deterioration of the bearing capacity of the bearing bush or of the chock would. As can be seen in Fig. 2, the angular range ß for the pressure build-up advantageously extends over almost 180 °, which is why the bearing capacity of the bearing according to the invention is greater than in comparable bearings, where the pressure build-up due to said inhomogeneities on the inside of the bearing bush a much smaller circumferential angle range is limited.

LIST OF REFERENCE NUMBERS

100 bearing bush

1 10 hole

120 Interior of the bearing bush

130 hydrodynamic oil pocket in the area of the oil supply

200 chock

210 inlet channel for oil

300 roller

310 Rolling pin α Circumferential angular range of the bore for the oil supply ß Circumferential angle range for a trouble-free pressure build-up

R direction of rotation of the roller

Q Transverse axis of the bearing bush

W half level

D Outer diameter of the bearing bush

Claims

claims:

1 . A bushing (100) for a chock (200) for rotatably supporting a roll neck (310) of a roll (300) in a rolling stand, having at least one bore (110) for oil supply to the one of the

Bearing bush clamped interior (120);

characterized in that

the at least one bore (1 10) for the oil supply only in a single circumferential angular range α of 70 ° <α <1 10 °, preferably 80 ° <α <100 ° in the direction of rotation (R) of the roller (300) relative to a half-plane (W), in which the maximum rolling force acts in the load case, is provided; and the inside of the bearing bush in a circumferential angular range ß with 180 ° <ß <360 ° in the direction of rotation of the roller (300) relative to the half-plane (W) is smooth.

2. bushing (100) according to claim 1,

characterized in that

hydrodynamic oil pockets (130) only outside the

Peripheral angle range (ß) on the wall of the interior of the bearing bush (100) are formed.

3. bushing (100) according to one of the preceding claims,

characterized in that

the bearing bush (100) has at each of its two end faces a radially projecting collar.

4. bearing bush (100) according to one of the preceding claims,

characterized in that the bearing bush is integrally formed.

Chock (200) with:

an inlet channel (210) for oil; and

a bearing bush (100) mounted rotatably in the chock for rotatably supporting a roll neck of a roll (300) in a roll stand, wherein in the wall of the bearing bush at least one bore (1 10) for an oil supply in the interior (120) clamped by the bearing bush is provided; and wherein the inlet channel (210) is aligned in the chock with the bore (1 10) in the wall of the bearing bush; characterized in that

the bearing bush (100) is formed according to one of the preceding claims.