Sleeve as part of an oil film bearing for a rolling-mill roll, oil film bearing, and rolling stand

Abstract

The invention relates to a sleeve as part of an oil film bearing for a rolling-mill roll, to an oil film bearing having a sleeve of this type, and to a rolling stand having an oil film bearing of this type. The sleeve (10) is intended to receive a roll journal (16) of the rolling-mill roll and is designed to be rotatably mounted in a bearing bush (18). The bearing bush (18) is disposed in a bearing housing (20) of a rolling stand, and an outer side (23) of the sleeve is cylindrical at least in parts, with an outside diameter D and a length L of the cylindrical portion, and an inner side of the sleeve is conical at least in parts, with a minimum inside diameter d of the conical portion (21). The following applies to the minimum inside diameter d: D ⋅ (c ⋅ ln (D) + bmin) ≤ d ≤ D ⋅ (c ⋅ ln (D) + bmax), where D is the outside diameter in units of millimeters, and where c and bmin and bmax are defined as follows: for L:D ≤ 0.78 : c=0.0305, bmin=0.5578, bmax=0.687; for 0.78 < L:D < 0.88 : c=0.0302, bmin=0.544, bmax=0.6706; for L:D ≥ 0.88 : c=0.0301, bmin=0.5278, bmax=0.655.

Description

[0001] Description

[0002] Sleeve as part of an oil film bearing for a rolling mill roll, oil film bearing and rolling stand

[0003] The invention relates to a sleeve as part of an oil film bearing for a rolling mill roll, an oil film bearing with such a sleeve and a rolling stand with such an oil film bearing.

[0004] Such a sleeve is designed to axially support a roll neck of the rolling mill roll. The oil film bearing, of which the sleeve is a part, further comprises a bearing bush surrounding the sleeve. The bearing bush is arranged in a bearing housing, which in turn is part of a rolling stand. The sleeve is designed for rotatable mounting in a bearing bush, so that the roll neck is also rotatably mounted via the bearing bush. For this purpose, an oil film is maintained during operation, at least in the load zone between the sleeve and the bearing bush.

[0005] An outer side of the sleeve is cylindrical in shape, at least in part. An inner side of the sleeve is conical in shape, at least in part, particularly in the region of the cylindrical portion of the outer side, with the conical shape extending along a sleeve longitudinal axis. In other words, the sleeve tapers in its interior, at least in part, in the intended insertion direction of a roll neck. The sleeve is thus designed to receive a roll neck that is correspondingly conically shaped, at least in part.

[0006] Such sleeves are known from US 4 093 321, US 4 384 748, US 4 286 830, US 4 351 576 and US 6 468 194 B2.

[0007] Over the last few decades, the design of the sleeve has been improved step by step. To increase the accuracy of the rolling process with regard to the uniform thickness of the produced sheets, the fitting and fixing device, in particular comprising keyways and spring wedges, between the roll neck and the sleeve was removed from the conical section of the inside of the sleeve. To increase the load-bearing capacity, the geometry of the sleeve was discussed in US 6 468 194 B2 and special sleeve geometries were proposed with regard to controlled deformation of the sleeve under load. In particular, the relevance of the thickness of the sleeve wall for controlled deformation of the sleeve was discussed.

[0008] The invention is based on the object of proposing a sleeve geometry that allows controlled deformation of the sleeve and thus high precision in the rolling process. Furthermore, an oil film bearing and a rolling stand with such a sleeve are to be specified.

[0009] This object is achieved with respect to the sleeve by the features of the sleeve according to claim 1 or claim 2, and with respect to the oil film bearing by the features of the oil film bearing according to claim 4, and with respect to the rolling stand by the features of the rolling stand according to claim 5. Embodiments and further developments are specified in the respective dependent claims.

[0010] The sleeve according to the invention is part of an oil-film bearing for a rolling mill roll. The sleeve is designed to accommodate a roll neck of the rolling mill roll and is constructed for rotatable mounting in a bearing bush. The bearing bush is thus also part of the oil-film bearing, as explained above. The bearing bush is arranged in a bearing housing of a rolling stand.

[0011] An outer side of the sleeve according to the invention is at least partially cylindrical with an outer diameter D and a length L of the cylindrical section.

[0012] An inner side of the sleeve is conical, at least in sections, with a minimum inner diameter d of the conical section. In particular, the conical section of the inner side is arranged at the level of the cylindrical section of the outer side, as viewed in the direction of a longitudinal axis of the sleeve, so that the conical section is opposite the cylindrical section. The cylindrical section can extend beyond the conical section.

[0013] The phrase "at least in sections" includes the alternatives "completely" and "sections", i.e. "partially". In the alternative "completely", the entire inside of the sleeve forms the conical section; in the alternative "sections", the inside has one or more further sections, for example a cylindrical section, in addition to the conical section. The same applies to the outside of the sleeve.

[0014] According to a first embodiment of the invention, the sleeve according to the invention is characterized in that the minimum inner diameter d is:

[0015] D • ( c • ln ( D) + b min ) < d < D - ( c - ln ( D) + b max )

[0016] In words : D "times" in brackets ( c "times" the "natural logarithm of D" plus b min ) is "less than or equal to" d and d is further "less than or equal to" D "times" in brackets ( c "times" the "natural logarithm of D" plus b max ) .

[0017] D is the outer diameter in millimeters. c and b m in and b max are defined as follows depending on the ratio L:D (in words: "L divided by D"): if L:D < 0.78, c= 0.0305 and b min =0.5578 and b max =0.687 at 0.78 < L:D < 0.88 is c=0.0302 and b min =0.544 and bma X = 0 , 6706 at L:D > 0.88 is c=0. 0301 and b min=0.5278 and b max =0.655

[0018] The first embodiment of the invention thus specifies which minimum inner diameter d of the sleeve must be provided for a certain outer diameter D and a certain length L of the cylindrical section of the outside of the sleeve, wherein b min and b max an interval results from which the inner diameter d can be selected to form a specific geometry.

[0019] According to a second embodiment of the invention, the sleeve according to the invention is characterized in that the minimum inner diameter d is: d = D • (c • In (D) + b)

[0020] In words: d "is equal to" D "times" in parentheses (c "times" the "natural logarithm of D" plus b) .

[0021] D is the outer diameter in millimeters. c and b are as follows depending on the

[0022] Ratio L:D (in words: "L divided by D") defined: at L:D < 0.78 is c=0.0305 and b=0.6224 at 0.78 < L:D < 0.88 is c=0.0302 and b=0.6073 at L : D > 0.88 is c=0.0301 and b=0.5914

[0023] The second embodiment of the invention thus specifies the minimum inner diameter d of the sleeve that must be provided for a specific outer diameter D and a specific length L of the cylindrical section of the outer side of the sleeve. Ultimately, the second embodiment is a special case of the first embodiment, since for each ratio L : D instead of b min and b max a fixed value for b is specified which leads to a fixed value for d instead of to an interval from which d can be selected according to the invention.

[0024] It has been shown that sleeves whose geometry and thus their dimensions correspond to the above-mentioned specifications according to the first and / or second embodiment of the invention are deformed in a controlled manner under load and thus advantageously contribute to a high accuracy of the rolling process.

[0025] A further development of the first and second embodiments of the invention provides that on the inside of the sleeve, on a narrow side of the conical section having the minimum inner diameter d, a cylindrical section with a cross-section that remains constant along the longitudinal axis is connected.

[0026] The oil film bearing according to the invention for a rolling mill roll is intended for installation in a rolling stand or is arranged in a rolling stand. The oil film bearing comprises a sleeve according to the invention and a bearing bush arranged in a bearing housing, in which the sleeve is rotatably mounted.

[0027] The rolling stand according to the invention is intended for supporting one or more rolling mill rolls. The rolling stand comprises one or more oil film bearings according to the invention. The invention is explained in more detail below with regard to further features and advantages based on the description of exemplary embodiments and with reference to the accompanying schematic drawings.

[0028] FIG 1 shows a schematic cross-sectional view of an embodiment of an oil film bearing according to the invention with a sleeve according to the invention, and

[0029] FIG 2 shows a schematic cross-sectional view of the sleeve according to the invention from FIG 1.

[0030] FIG. 1 shows an embodiment of an oil-film bearing 12 according to the invention and a sleeve 10 as part of this oil-film bearing 12. The oil-film bearing 12 further comprises a bearing bush 18, which is arranged in a bearing housing 20 of the oil-film bearing 12. The sleeve 10 from FIG. 1 is shown again in FIG. 2.

[0031] The oil film bearing 12 is arranged in a rolling stand (not shown) and is intended for supporting a rolling mill roll. The sleeve 10 of the oil film bearing 12 accommodates a roll neck 16 of the rolling mill roll. The sleeve 10, in turn, is rotatably received in the bearing bush 18. During operation, the sleeve 10 is supported by a thin oil film (not shown), which is hydrodynamically maintained in a load zone between the sleeve 10 and the bearing bush 18.

[0032] An outer side 23 of the sleeve 10 is partially cylindrical. An inner side of the sleeve is partially conical. The diameter of the conical section 21 tapers from the entry surface of the roll neck 16 in the insertion direction of the roll neck 16. The sleeve 10 removably receives the roll neck 16, with a conical section of the roll neck being received by the conical section of the sleeve 10. The sleeve 10 is fixed to the roll neck 16 in a rotationally fixed manner by the locking elements 14.

[0033] The geometry of the sleeve 10 is evident in FIG 2, and the dimensions relevant to the invention are marked. The conical section 21 of the inside of the sleeve 10 has a minimum inside diameter d on its narrow side opposite the inlet surface. Also shown is the taper angle α of the conical section 21. The outside 23 of the sleeve 10 is cylindrical with an outside diameter D and a length L. This results in a minimum material thickness t and a maximum material thickness t' of the conical section 21 of the sleeve 10.

[0034] Adjacent to the narrow side of the conical section 21 of the inside of the sleeve 10 is a cylindrical section 22 of the inside of the sleeve 10. Keyways 15 are formed in this cylindrical section 22, which cooperate with the locking elements 14 of the roll neck 1, for example, spring wedges, to form a rotationally fixed connection. No such keyways are provided in the conical section 21; these are formed exclusively in the cylindrical section 22.

[0035] The relative size ratios of the three geometric dimensions "minimum inner diameter d" of the conical section and "outer diameter D" and "length L" of the cylindrical section of the outer side 23 of the sleeve 10, which are only shown schematically in the figures, are derived from the formulas given according to the invention. An example is given below:

[0036] Outer diameter D = 1,088.00 mm

[0037] Length L = 876.50 mm Therefore L:D = 876.50 mm : 1,088.00 mm = 0.8056

[0038] According to the invention, the first embodiment of the invention provides: c = 0.0302 bmin = 0.544 bmax = 0.6706

[0039] According to the formula

[0040] D • (c • ln(D) + b min ) < d < D • (c - ln(D) + b max ) the following applies to a sleeve according to the invention for the minimum inner diameter d:

[0041] 821.6 mm < dd 959.4 mm

[0042] According to the second embodiment of the invention, based on the above-mentioned values, the following is provided: c = 0.0302 b = 0.6073

[0043] According to the formula d = D • (c • In (D) + b), the following applies for a sleeve according to the invention for the minimum inner diameter d: d = 890.5 mm List of reference symbols

[0044] 10 sleeves

[0045] 12 oil film bearings

[0046] 14 Locking element

[0047] 15 keyway

[0048] 16 whalebones

[0049] 18 Bearing bush

[0050] 20 bearing housings

[0051] 21 conical section of the inside of the sleeve 10

[0052] 22 cylindrical section of the inside of the sleeve 10

[0053] 23 Outside of the sleeve 10

[0054] L Length of the cylindrical section of the outer side 23 of the sleeve 10 d Minimum inner diameter of the conical section 21

[0055] D Outer diameter of the cylindrical section of the

[0056] Outside 23 of the sleeve 10 a taper angle of the conical section 21 t minimum material thickness of the conical section 21 t ' maximum material thickness of the conical section 21

Claims

Patent claims 1. Sleeve (10) as part of an oil film bearing (12) for a rolling mill roll, wherein the sleeve (10) is intended to receive a roll neck (16) of the rolling mill roll and is designed for rotatable mounting in a bearing bush (18), wherein the bearing bush (18) is arranged in a bearing housing (20) of a rolling stand, wherein an outer side (23) of the sleeve is at least partially cylindrical with an outer diameter D and a length L of the cylindrical section, wherein an inner side of the sleeve is at least partially conical with a minimum inner diameter d of the conical section (21), characterized in that the following applies to the minimum inner diameter d: D • (c • ln(D) + b min ) < d < D • (c - ln(D) + b max ) where D is the outer diameter in millimeters, where c and b min and b max are defined as follows: for L:D < 0.78, c= 0.0305, bmin =0.5578, b max =0.687 at 0.78 < L:D < 0.88 is c=0.0302, b min =0.544, b max =0.6706 for L:D > 0.88 is c=0.0301, b min =0.5278, b max =0.655 2. Sleeve (10) as part of an oil film bearing (12) for a rolling mill roll, wherein the sleeve (10) is intended to receive a roll neck (16) of the rolling mill roll and is designed for rotatable mounting in a bearing bush (18), wherein the bearing bush (18) is arranged in a bearing housing (20) of a rolling stand, wherein an outer side (23) of the sleeve is at least partially cylindrical with an outer diameter D and a length L of the cylindrical section, wherein an inner side of the sleeve is at least partially conical with a minimum inner diameter d of the conical section (21), characterized in that the following applies to the minimum inner diameter d: d = D • (c • In (D) + b) where D is the outer diameter in the unit millimeters, where c and b are defined as follows: for L:D < 0.78, c=0.0305, b=0.6224 for 0.78 < L:D < 0.88, c=0.0302, b=0.6073 for L:D > 0.88, c=0.0301, b=0.5914 3. Sleeve (10) according to claim 1 or 2, characterized in that on the inside of the sleeve (10) at a narrow side of the conical section (21) having the minimum inner diameter d, a cylindrical section (22) with a cross-section that remains constant along the longitudinal axis is connected.

4. Oil film bearing (12) for a rolling mill roll, wherein the oil film bearing (12) is intended for arrangement in a rolling stand or is arranged in a rolling stand, wherein the oil film bearing (12) comprises a sleeve (10) according to one of claims 1 to 3 and a bearing housing (20) arranged bearing bush (18) in which the sleeve (10) is rotatably mounted.

5. Rolling stand for supporting one or more rolling mill rolls, the rolling stand comprising one or more oil film bearings (12) according to claim 4.

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