EP3302836B1 - Roll assembly - Google Patents

Description

The invention relates to a roller arrangement for rolling rolling in a rolling mill according to the preamble of patent claim 1.

State of the art

In oil film bearings, such as are commonly used in roll stands for metallic rolling stock for the storage of support rollers, a roll neck rotates in a stationary bearing bush, wherein the bearing bush is arranged in a chock. The diameter difference between the roll neck and the bearing bush is usually in the range of 1 ‰ of the bearing diameter, i. H. about 1 mm clearance at 1 m bearing diameter, which is why a corresponding annular gap between the roll neck and the bearing bush is formed. The annular gap is typically with lubricants, z. B. oil filled, so that forms an oil film in the annular gap.

If during operation of the rolling stand, an external force, for. B. the rolling force applied to the storage, so first shifts the rotating roll neck eccentrically to the bearing bush in the radial direction against the outer direction of force. The annular gap between the roll neck and the bearing bush then has on one side a minimum cross section and exactly opposite a maximum cross section. The oil, which is supplied via hydrodynamic pockets the annular gap is transported by the adhesive condition on the rotating surface of the roll neck in the region of the narrowest cross-section. As the cross-section of the gap narrows to the narrowest point, the oil is squeezed out to the side of the bearing. At the same time, however, the pressure in the oil film increases, whereby the bearing is able to carry an external larger force. The oil, which is pushed out to the two bearing sides, usually referred to as the side flow of the camp.

The pamphlets EP 1 031 389 B1 . EP 1 699 575 B1 and DE 198 31 301 A1 describe sealing devices for rolls in rolling mills.

The publication DE 3117 746 A1 describes a hydrodynamic radial bearing.

The OIL-FILM BEARINGS FOR ROLLING-MILLS technical documentation, Copyright 1967, American Society of Lubrication Engineers, describes hydrostatic oil film bearings for rolls in a rolling mill.

The oil film between the roll neck and the roll neck receiving bearing surface is hereinafter also referred to as a lubricating film. A disadvantage of systems without Seitenflussreduzierung is the high side flow of the lubricant, even if this is not required for cooling. It requires a large supply and a large periphery to provide enough lubricant. At low speeds additional hydrostatic support is required to accommodate larger rolling forces; otherwise the bearing capacity of the bearing is comparatively rather low. The specific size is also high depending on the required rolling force.

A disadvantage of systems with a completely sealed annular gap without drain possibility for the lubricant is, inter alia, that the operating temperature of the lubricant and the roll neck increases, especially at higher speeds and therefore expensive cooling systems are required to limit the increase in temperature or to keep uniform. Due to the increase in temperature, the viscosity of the lubricant decreases. Consequently, the lubricant pressure also decreases and it reduces the bearing capacity of the storage. Most are closed Systems integrated check valves to prevent running of the cooling circuit.

The German patent DE 690 07 079 T2 discloses a roller assembly according to the preamble of claim 1. Specifically, the roller assembly disclosed therein comprises: a roller having a roll barrel and at least one roll neck; a chock with a rotatably mounted bushing, which has a receiving opening for receiving the roll neck, wherein the inner diameter of the receiving opening relative to the outer diameter of the roll neck is formed so larger that between the bearing bush and the roll neck an annular gap for receiving a lubricant remains; a sealing ring arranged on the roll barrel-side end face of the receiving opening for sealing the annular gap there; and a arranged on the roller bale far end face of the receiving opening sealing ring for local sealing of the annular gap.

Object of the invention

The object of the invention is to develop a known roll order to the effect that their carrying capacity or the rolling force can be increased while maintaining or reducing their size, without overheating the roll assembly. The roller assembly according to the invention should also be easy to install and retrofit in existing systems.

This object is solved by the subject matter of claim 1. Characteristic of the roller assembly according to the invention is that the bearing bush - seen in the circumferential direction - is divided into a flow angle range and Absperrwinkelbereich; in that the bearing bush has at least one outflow channel in the passage angle region for deriving the lubricant from the Annular gap in an oil receiving space; that the flow angle range extends adjacent to the Absperrwinkelbereich over an angular range of 360 ° minus Absperrwinkelbereich; and that the Absperrwinkelbereich a, starting from A + y with -10 ° <γ <25 °, extending against the direction of rotation of the roller by a maximum of 270 °, where A defines a support load point, which by the angular position A of the narrowest gap (h _min ) is represented in the load case between roll neck and chock. where A defines a support load point, which is represented by the angular position A of the narrowest gap (h _min ) in the load case between roll neck and chock.

The roller assembly according to the invention initially, due to the blocking of the side flow of the lubricant by means of the sealing rings, leads to an increase in pressure of the lubricant in the annular gap in the region of the support load point and thus to a load capacity increase or rolling force increase of the roller assembly. At the same time, the thickness of the lubricating film is increased in the region of the support load point and thus improves the reliability, for example with respect to edge runners and with respect to the startup behavior. In particular, in the front stands of a rolling mill, where due to the relatively low speed only little heat in the camp arises and therefore only a little cooling is necessary, the pressure build-up can be realized simply and advantageously by providing the sealing rings.

With the aid of appropriate calculation models, based on long-term experience and experiments, it is already possible during planning of the roller arrangement to define the shut-off area and the passage area with the drainage channels for the lubricant for a bearing bush in such a way that a desired load-bearing capacity of the roller arrangement can be realized even at higher speeds without the roller assembly overheating. Structural changes to the chock and / or the roller is usually not required. As the angle for the shut-off area increases, the flow of lubricant out of the annular gap is reduced. The reduction or throttling of the side flow of the lubricant within the storage advantageously leads to an increase in the load capacity of the roller assembly.

This increase in carrying capacity is advantageously achieved without the risk of overheating of the storage. This is true because in the complementary to the Absperrwinkelbereich flow angle range of the bearing bush of 360 ° minus Absperrwinkelbereich the at least one drainage channel according to the invention is dimensioned / is such that it allows sufficient lateral outflow of the lubricant, which in turn sufficient removal of heat from the camp guaranteed.

The invention advantageously allows easy retrofitting in existing facilities. Without enlarging the space, for example, in the course of Modernization measures on existing rolling mills the rolling force and thus the efficiency of the existing rolling mill can be increased by up to 40%. Existing plants can increase in rolling demands, z. B. be converted by the processing of other material grades or material thicknesses, easily and inexpensively. A previous bushing can be easily replaced by a bearing bush according to the invention. In addition, the ball-side and bale-distant sealing ring can be retrofitted to existing roller assemblies.

If no increased rolling force is required, the roller arrangement in new systems in advance can be made smaller overall to ensure the same load capacity as before. This saves above all space, material costs and production time.

According to a first embodiment, a pin bushing is provided for mounting on the roll neck. The pin bushing can advantageously be easily and inexpensively replaced in case of wear. The annular gap is then formed between the bearing bush and the pin bushing.

According to a further embodiment, it is provided that the support load point A is arranged in the load case in an angular range of φ = +/- 25 °, relative to the center axis Y of the roller perpendicular to the plane of the rolling stock.

According to a further embodiment of the invention, the bearing bush in the flow angle region at least one ball-side drainage channel for fluid-conducting connection of the annular gap with a ball-side oil receiving space and at least one balefernen drainage channel for fluid-conducting connection of the annular gap with a ballenfernen Ölaufnahmeraum. The two drainage channels advantageously allow a radial and lateral outflow of oil from the annular gap of the bearing bush. With the effluent oil is dissipated more heat from the annular gap than an already existing collecting return in the chock, and so overheating of the annular gap or in particular the pin bushing and the roll neck is reliably prevented even at increased load.

The particular radial outflow channels are advantageously arranged distributed in the circumferential angular range of the pin bushing in the circumferential direction or extend in the circumferential direction. For example, they may have a slit-shaped cross-section which extends in the circumferential direction within the flow angle range, or a plurality of drainage channels may be provided which are arranged side by side on the ball side or on the ball-distal side in the flow angle region of the bearing bush.

The bearing bush can have an oil pocket in the passage angle region on its inner side facing the roll neck, and the at least one drain channel is then preferably arranged so that it can discharge the oil from the oil pocket into the oil receiving space.

The roller of the roller arrangement according to the invention may be a work roll, a support roll or an intermediate roll.

Further advantageous embodiments of the invention are the subject of the dependent claims.

Figur 1

die erfindungsgemäße Walzenanordnung gemäß einem ersten Ausführungsbeispiel in einem Längsschnitt;

Figur 2

die erfindungsgemäße Walzenanordnung in einem Querschnitt;

Figur 3

die erfindungsgemäße Walzenanordnung gemäß einem zweiten Ausführungsbeispiel;

Figur 4

die erfindungsgemäße Walzenanordnung gemäß einem dritten Ausführungsbeispiel; und

Figur 5

die erfindungsgemäße Lagerbuchse mit verschiedenen Varianten für die Abflusskanäle

zeigt.The description is attached to five figures, wherein

FIG. 1

the roller assembly according to the invention according to a first embodiment in a longitudinal section;

FIG. 2

the roller assembly according to the invention in a cross section;

FIG. 3

the roller assembly according to the invention according to a second embodiment;

FIG. 4

the roller assembly according to the invention according to a third embodiment; and

FIG. 5

the bearing bush according to the invention with different variants for the drainage channels

shows.

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

FIG. 1 shows the roller assembly 100 according to the invention according to a first embodiment. The roll arrangement 100 comprises a roll 110 with a roll bale 112 and a roll neck 114. In a roll stand, the roll is rotatably mounted in a chock 120, more precisely in a bearing bush 130 arranged rotationally fixed in the chock. The bearing bush 130 has a receiving opening for receiving the roll neck 114, wherein the inner diameter of the receiving opening relative to the outer diameter of the roll neck or on this mounted pin bushing 116 is formed so larger that between the bearing bush and the roll neck or the pin bushing 116 an annular gap 180 for receiving a lubricant, typically oil remains; please refer FIG. 2 ,

At the roller barrel side end face of the receiving opening, a sealing ring 140 is arranged for sealing the annular gap there with respect to a Roller box-side receiving space 160. Similarly, a further sealing ring 150 is arranged for local sealing of the annular gap 180 relative to the local roller barrel remote oil receiving chamber 170 at the roller bale remote end face of the receiving opening.

As in FIG. 1 shown, the bearing bush 130 at least one outflow channel 132, for discharging the lubricant from the annular gap 180 in one of the oil receiving chambers 160, 170. In the in FIG. 1 a baleseitiger outflow channel 132-1 and a ballenferner outflow channel 132-2 is provided for discharging oil from the annular gap 180. For this purpose, the drainage channels 132-1, 132-2 are fluid-conducting with the annular gap and the respective oil receiving space 160, 170 connected. As in FIG. 1 shown, the drainage channels extend by way of example in sections in the radial and axial directions.

FIG. 2 shows a cross section through the roller assembly according to the invention under the load of the rolling force F, which acts here for example in the direction of the center plane y. Due to the interaction of the action and the reaction of the rolling force F, the roll pin 114 optionally displaces eccentrically within the bearing bush 130 together with the pin bushing 116, so that an asymmetric annular gap 180 or an asymmetric oil film is produced. The minimum height or thickness h _min assumes the annular gap 180 at the position of the support load point A.

According to the invention, the bearing bush 130 is divided, as seen in the circumferential direction, into a passage angle range β and a shut-off angle range a, which is understood as the difference between 360 ° and the flow angle range β. The Absperrwinkelbereich a extends, starting from A + y with - 10 ° <γ <+ 35 ° against the direction of rotation of the roller by a maximum of 270 °. Accordingly, the flow area is defined as the complement angle range to the Absperrwinkelbereich, ie to 360 ° - the Absperrwinkelbereich α.

The support load point A is in the load case in an angular range of φ = +/- 25 ° relative to the perpendicular to the plane of the rolling central axis Y of the roller.

FIG. 3 shows a second embodiment of the roller assembly, more precisely for a possible guidance of the drainage channels 132. Specifically, the second embodiment provides that the ball-side and the baleferne spillway 132-1, 132-2 not only - starting from the annular gap 180 - in radial Direction through the bearing bush 130, but from this further through the chock 120 is guided to exit at the end faces in the respective oil receiving chambers 160, 170, preferably in the axial direction.

FIG. 4 shows a third embodiment of the inventive arrangement, in particular for a possible guidance of the drainage channels. As a special feature, it can be seen here that the bearing bush 130 has a collecting oil pocket 136 on its inner side facing the roll neck 114 and that the at least one outflow channel 132-1, 132-2 is in fluid-conducting connection with the oil pocket 136. The oil pocket is a local recess on the inside of the bushing and so the oil bag acts as a local volume enlargement of the annular gap; in the area of the collecting oil pocket, the thickness of the annular gap 180 and thus the thickness of the oil film therein is increased.

The outflow channels 132, 132-1, 132-2 according to the invention are always formed only in the passage angle range β, but never in the Absperrwinkelbereich α.

FIG. 5 shows possible arrangements and cross-sectional shapes for the drainage channels. The cross-sectional shapes shown therein, slit-shaped, round or rectangular are to be understood merely as examples; Of course, the drainage channels can have any cross-sectional shape. It is advantageous if the drainage channels extend in the circumferential direction of the bearing bush, be it slot-shaped, for example, as in the left in FIG FIG. 5 shown or in the form of a plurality of circumferentially distributed singular drainage channels, as shown right in FIG. 5 shown.

LIST OF REFERENCE NUMBERS

100

roll arrangement

110

roller

112

roll barrel

114

roll neck

116

pin bush

120

chock

130

bearing bush

132

culvert

132-1

Bale-side drainage channel

132-2

Ballenferner drainage channel

136

oil pocket

140

Roller barrel side sealing ring

150

Roller bale remover sealing ring

160

Bale-side oil intake chamber

170

Ballenferner oil receiving room

180

annular gap

α

Absperrwinkelbereich

β

Flow angle range

φ

Angular range for support load point

A

Support load point

γ

angle

Claims (9)

1. Roll assembly (100) for rolling rolling material in a rolling installation, comprising:

   a roll (110) with a roll barrel (112) and at least one roll pin (114);

   a chock (120) with a bearing bush (130) which is arranged to be secure against relative rotation and which has a receiving opening for reception of the roll pin, wherein the inner diameter of the receiving opening is formed to be larger relative to the outer diameter of the roll pin in such a way that an annular gap (180) for reception of a lubricant remains between the bearing bush and the roll pin;

   a sealing ring (140), which is arranged at the end of the receiving opening at the roll-barrel side, for sealing of the annular gap thereat; and

   a sealing ring (150), which is arranged at the end of the receiving opening remote from the roll barrel, for sealing of the annular gap thereat;

   characterised in that

   the bearing bush (130) as seen in circumferential direction is divided into a throughflow angular region β and a blocking angular region α;

   the bearing bush (130) has in the throughflow angular region (β) at least one outflow channel (132) for conducting the lubricant out of the annular gap (180) into an oil reception space (160, 170);

   the throughflow angular region β extends adjacent to the blocking angular region over an angular range of 360° minus the blocking angular region α; and

   the blocking angular region α extends oppositely to the direction of rotation of the roll through a maximum of 270° starting from A + y, wherein -10° < y < 35°, wherein A defines a supporting load point which is represented by the angular position A of the narrowest gap h_min in the load case between roll pin and chock.
2. Roll assembly (100) according to claim 1, characterised by a pin bush (116) placed on the roll pin (114) to be secure against relative rotation; wherein the receiving opening of the bearing bush (130) is formed for reception of the roll pin (114) together with the pin bush; and wherein the annular gap (180) for the lubricant is formed between the bearing bush (130) and the pin bush (116).
3. Roll assembly (100) according to one of the preceding claims, characterised in that the supporting load point (A) in the load case is arranged in an angular range of ϕ = +/-25° referred to the centre axis Y, which is perpendicular to the plane of the rolling material, of the roll.
4. Roll assembly (100) according to any one of the preceding claims, characterised in that the oil receiving space is a barrel-side oil receiving space (160) between the chock (120) and the roll barrel (112) or a barrel-remote oil receiving space (170) at the end of the roll pin (114) remote from the barrel.
5. Roll assembly (100) according to claim 4, characterised in that the bearing bush (130) has in the throughflow angular region (β) at least one barrel-side outflow channel (132-1) for fluid-conductive connection of the annular gap (180) with the barrel-side oil receiving space (160) and at least one barrel-remote outflow channel (132-2) for fluid-conductive connection of the annular gap (180) with the oil receiving space (170) remote from the barrel.
6. Roll assembly (100) according to any one of the preceding claims, characterised in that the at least one outflow channel (132-1, 132-2) is led from the bearing bush (130) through the chock (120) and from the chock opens into one of the oil receiving spaces (160, 170).
7. Roll assembly (100) according to any one of the preceding claims, characterised in that at least one outflow channel (132) has a slot-shaped cross-section which extends in circumferential direction within the throughflow angular region β; and/or a plurality of outflow channels (132) arranged adjacent to one another in circumferential direction within the throughflow angular region β is provided.
8. Roll assembly (100) according to any one of the preceding claims, characterised in that the bearing bush has an oil collecting pocket (136) in the throughflow angular region on its inner side facing the roll pin; and the at least one outflow channel (132) is in fluid-conductive connection with the oil pocket (136).
9. Roll assembly (100) according to any one of the preceding claims, characterised in that the roll (110) is a working roll, a backing roll or an intermediate roll.

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