Seal to prevent lubricant escaping, and rolling stand having said seal

Abstract

A seal (100) for sealing a lubricant space prevents lubricant (320) escaping. A rolling stand has a seal of this kind. The seal (100) is made at least partially from elastic material. To enable a pressing force FR, with which the bottom face (112) of the seal is pressed against an opposite contact surface (218), for example of a roll journal (212), to be variably set, the seal (100) has at least two cavities, which are separated from each other in the circumferential direction and which are open towards the lubricant space of the bearing.

Claims

1. A rolling stand (200), comprising: at least one roller (210) with two roll journals (212) and a roller body (214) for rolling a rolled material; at least one chock (220) for rotatably supporting the roller (210) in the rolling stand (200), wherein the chock (220) forms a receiving opening for receiving one of the roll journals (212), wherein an inner diameter of the receiving opening is larger than an outer diameter of the roll journal in such a manner that, between the chock and the roll journal an annular gap (300) for receiving a lubricant (320) is formed; and a seal for sealing the annular gap, which represents a lubricant space of a bearing, at least in a predetermined circumferential angular range, arranged in a non-rotatable manner relative to the rotatable roller at an end proximal to the roller body and/or at an end remote from the roller body of the chock (220); wherein the seal (100) is at least partially formed from an elastic material, wherein the seal has at least two cavities (110) which are separated from each other in a circumferential direction and which are independently open towards the lubricant space of the bearing for feeding the lubricant (320) from the lubricant space (300) of the bearing to be sealed into the cavities whereby the at least two cavities (110) can expand independently depending on different lubricant pressure in each of the at least two cavities (110), wherein a groove (230) that is open towards the roll journal (212) and into which the seal (100) can be inserted is formed at the end proximal to the roller body and/or at the end remote from the roller body of the chock (220).

2. The rolling stand according to claim 1, wherein the seal (100) is formed as a ring segment and has a predetermined limited length (L) to which the following applies:
L<total circumference of the annular gap.

3. The rolling stand according to claim 1, wherein the seal (100) is designed in the form of a ring seal.

4. The rolling stand according to claim 3, wherein an outer diameter (DD) of the ring seal in its unloaded state is essentially equal to a diameter of the groove (240) at its bottom.

5. The rolling stand according to claim 3, wherein an inside diameter (dD) of the ring seal (100) is larger than an outside diameter (DZ) of the roll journal (212) at an axial height of the ring seal.

6. The rolling stand according to claim 1, wherein an axial outer side of the groove is formed by a perforated disk (240) that can be detachably connected to the chock.

7. The rolling stand according to claim 1, wherein the seal (100) has at least one superelevation (130) on its end face turned away from and/or turned towards the chock.

8. The rolling stand according to claim 1, wherein the seal (100) has a rectangular cross-section; and in that the sealing surface of the seal is turned towards the roll journal.

9. The rolling stand according to claim 3, wherein the at least two cavities (110) on the surface of the ring seal are also designed to be open towards the chock (220).

10. The rolling stand according to claim 9, wherein the chock (220) has, on its end face turned towards the seal, pins (228) projecting in an axial or radial direction for engaging in the at least two cavities (110) on the surface of the seal (100).

11. The rolling stand according to claim 10, wherein a volume of the at least two cavities (110) into which the pins project is greater than a volume of the pins (228) engaging in the at least two cavities.

12. The rolling stand according to claim 1, wherein the seal does not include a circumferential groove to connect the at least two cavities (110).

13. The rolling stand according to claim 1, wherein the seal (100) extends radially beyond the groove (230) with a bottom face (112) of the seal being arranged outside the groove (230), and wherein each of the at least two cavities (110) is open towards the groove and in fluid communication with the lubricant space only through a dedicated feed channel (120) that opens towards the lubricant space on an inside face of the seal outside of the groove.

14. The rolling stand according to claim 1, wherein pins (228) extend from the chock (220) into the cavities (110).

15. The rolling stand according to claim 1, wherein in an unloaded state, an axial width (a) of the seal (100) is greater than a width (A) of the groove (230) in the axial direction (R).

16. The rolling stand according to claim 1, further comprising a bearing bush (222) arranged in a non-rotatable manner in the chock (220).

17. The rolling stand according to claim 1, further comprising a journal bush (216) drawn on the one of the roll journals (212).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The description is accompanied by 5 figures, wherein the following are shown

(2) FIG. 1 shows the seal in accordance with the disclosure.

(3) FIG. 2 shows a rolling stand from the prior art.

(4) FIG. 3 shows the bearing arrangement of a roller in a chock.

(5) FIG. 4 shows the design and arrangement of the seal in the bearing arrangement as shown in FIG. 3 in an enlarged view.

(6) FIG. 5 shows a cross-section of the receiving space spread out by a bearing bush or chock with an inserted roll journal.

DETAILED DESCRIPTION

(7) The invention is described in detail below with reference to the figures mentioned in the form of exemplary embodiments. In all figures, the same technical elements are marked with the same reference signs.

(8) FIG. 1 shows the seal 100 designed in accordance with the disclosure. It can be used to seal a lubricant space (not shown in FIG. 1) to prevent lubricant escaping. It is at least partially made of an elastic material and has a plurality of cavities 110 of any arbitrary shape in its interior. The cavities 110 are shown in FIG. 1 only as examples as cylindrical recesses 110, which are open towards the surface of the seal. Alternatively, the cavities 110 can also be formed completely in the interior of the seal; they are then connected to the surface of the seal in a fluid-conducting manner via feed channels 120. The feed channels are used to feed the lubricant from the lubricant space 300 of a bearing, in particular an oil film bearing, into the respective cavities 110.

(9) In FIG. 1, the lower side of the seal 100 forms a bottom face 112, with which the seal is pressed against a contact surface of a typically moving object, for example a roll journal.

(10) At least to a large extent, the recesses or the feed channels 120 open into a first lubricant space 300 of the bearing to be sealed. In this manner, it is ensured that the lubricant and the pressure from the first annular gap 300 is transferred to the cavities. The pressure from the lubricant space, which may vary, is then always adjusted in the cavities. With regard to the purpose of this, please refer to the above explanations in the general part of the description.

(11) The reference number 225 and the hatching indicate wall areas of a groove in which the seal can typically be inserted. Such wall areas then cover most of the surface of the seal. Only the feed channels and/or recesses on the non-overlaid areas of the surface of the seal are in in a fluid-conducting connection with the first lubricant space 300; see also FIG. 4.

(12) As shown in FIG. 1, the recesses 110 may also be open to surface sections of the seal other than the lubricant compartment 300. This is particularly advantageous for the interaction of such recesses with the pins on the chock described below.

(13) FIG. 1 also shows an example of a first group of recesses 110 and a second group of recesses 110, wherein the volume of the recesses of the first group is larger than the volume of the recesses of the second group. The different volumes bring about a different expansion of the seal and thus possibly a different proportion of a sealing force exerted by the seal at the same supplied pressure.

(14) The seal in FIG. 1 has a width a; such width corresponds to the width of the bottom face 112 as an example. It can also be seen that the seal has an exemplary rectangular cross-section. The separate cavities 110 or recesses 110 are preferably arranged in a manner evenly distributed over the length or circumference of the seal. This has the advantage that the seal 100 therefore has the same properties at every point or length section. For sealing cylinders, such as a roll journal 212, the seal 100 can be designed in ring shape as a ring seal; see FIG. 5. The bottom face 112 is then designed to be turned towards the center or center point of the ring seal or in other words the surface or contact surface of the cylinder; see FIG. 5.

(15) FIG. 2 shows a rolling stand according to the prior art. The rolling stand 200 has at least one roll 210 (here, as an example, four rollers 210), each with two roll journals 212 and one roller body 214. In particular, the two central work rollers shown in FIG. 2 are used for rolling rolled material. Each of the rollers 210 is rotatably mounted with its roll journals 212 in a chock 220, also called a bearing housing.

(16) FIG. 3 shows such bearing arrangement in detail in a longitudinal section. The roller 210 with its roll journal 212 and roller body 214 can be seen. A journal bush 216 is drawn on the roll journal. The roll journal with the journal bush is mounted in a receiving opening, which is spread out by a bearing bush 222. The bearing bush 222 is arranged in a non-rotatable manner in the chock 220. An annular gap 300 is formed between the bearing bush 222 arranged in a non-rotating manner and the journal bush 216 rotating with the roll journal 212, which annular gap is filled with lubricant 320 during the operation of the rolling stand. In the annular gap, the lubricant is then under high pressure, typically of several 100 bar. In FIG. 3, the annular gap 300 is sealed in an exemplary manner both at its end on the roller body side and at its end remote from the roller body by the ring seal 100. The ring seal 100 does not have to be designed over its entire circumference; in principle, only one section of the ring seal can be designed accordingly.

(17) It can also be seen in FIG. 3 that the bearing bush 222 has a groove 230 at its end on the roller body side and at its end remote from the roller body, which each is open towards the roll journal 212 and into which the ring seal 100 is inserted. In the example shown in FIG. 3, the outer sides of the two grooves 230 are not formed by the bearing bush 222. Rather, each of the outer sides of the grooves there is formed by perforated disks 240, which are screwed to the bearing bush 222 with screws 245. Since the width a of the ring seal 100 in unloaded state and, if applicable, taking into account the superelevations 130, see FIG. 1 in the axial direction R, is intentionally designed slightly larger than the width A of the groove, which is structurally specified by the bearing bush 222, it is possible that, by tightening the screws 245, the axial force with which the ring seals 100 are squeezed in the groove can be variably adjusted. Due to the isotropic behavior of the material of the seal 100, the axial crushing or compression not only reduces the width of the ring seal, but also causes the ring seal to expand in the radial direction. For this reason, a variation in the axial clamping force automatically causes a variation in the preload or radial pressing force with which the bottom face 112 of the seal 100 is pressed against the opposite contact surface of the journal bush 216.

(18) FIG. 4 shows, once again, the installation of the seal 100 in the bearing bush 222 in detail.

(19) The reference sign 225 indicates the wall areas of the groove in the chock or the bearing bush, against which the seal 100 is pressed upon installation in the groove. In other words, the seal and the cavities on the surface of the seal are covered and sealed by such wall areas, if applicable. Only cavities or feed channels arranged radially further inwards open into the first annular gap 300.

(20) It can also be seen that the thickness of the lubricating film 330 in the second annular gap 140 between the bottom face 112 of the seal 100 and the opposite contact surface 218 of the journal bush 216 is considerably less than the thickness of the annular gap 300. This is achieved by the fact that the ring seal 100 protrudes in the radial direction largely into the originally existing ring gap 300. In FIG. 4, the proportions are shown in an exaggerated manner. In fact, due to the radial pressing force FR, the ring seal presses on the contact surface 218 of the journal bush 216. However, due to the high pressure conditions mentioned above, the lubricating film 330 in question, with a thickness of only a few μm, nevertheless forms between the bottom face 112 and the contact surface 218. The pressure in the first annular gap 300 is significantly greater than that in the second annular gap 140.

(21) It can also be seen that the ring seal 100 is inserted into the groove 230 in such a manner that its recesses 110 are engaged with pins 228, which extend from the end face of the bearing bush 222 bounding the groove 230, preferably in the axial direction R. With a design of radially arranged cavities, the pins extend perpendicular to the axial direction. The remaining cavity 116 is sealed towards the bearing bush 222 due to the axial or radial pressing force with which the ring seal 100 is pressed into the groove by means of the perforated disk 240; for this reason, it functions as a cavity 110 within the meaning of the disclosure, which cavity opens into the lubricant space 300 of the (oil film) bearing via a feed channel 120. The effect of the variation, in particular the increase, of the total radial force as a function of the pressure conditions in the area of the lubricating film 330, as caused by the feed channel, was described in detail above.

(22) FIG. 5 has already been briefly described in the introduction. It shows a cross-section through the receiving space spread out by the bearing bush for receiving the roll journal 212. As can be seen from an overview of FIGS. 4 and 5, the receiving space is limited in the radial direction not only by the bearing bush 222, but in particular also by the ring seal 100, which typically protrudes further inwards. In the receiving space of the housing, the roll journal 212 rotates, if applicable with the drawn-on journal bush 216. For the operation of the roll bearing as a hydrodynamic oil film bearing, the inner diameter dD of the ring seal 100 is larger than the outer diameter DZ of the roll journal 212 at the axial level of the ring seal, optionally with the drawn-on journal bush 216. During operation as a hydrodynamic oil film bearing, the ring seal 100 then presses itself so closely against the surface or contact surface 218 of the roll journal that only the lubricating film 330 is formed there, only in the circumferential angular range of the minimum lubricating film, which is approximately in the area of the maximum rolling force FW.sub.max. In the remaining circumferential angular range, the bottom face 112 of the ring seal 100 no longer abuts the contact surface 218 of the roll journal 212; rather, the distance between such two surfaces is greater than the thickness of the lubricating film in the area of the maximum rolling force; this applies in particular due to the overdimensioning in question of the ring seal 100. The overdimensioning in question and the resulting greater gap between the bottom face 112 and the contact surface 218 advantageously enables an axial outflow of lubricant in the circumferential angular range outside the area of the maximum rolling force. The outer diameter DD of the ring seal 100 typically corresponds to the inside diameter of the bottom of the groove 230.

LIST OF REFERENCE SIGNS

(23) 100 Seal

(24) 110 Cavity or recess

(25) 111 Bottom face pattern

(26) 112 Bottom face

(27) 116 Remaining cavity

(28) 120 Feed channel

(29) 130 Superelevation

(30) 140 Annular gap or lubricant space under the seal

(31) 200 Rolling stand

(32) 210 Roller

(33) 212 Roll journals

(34) 214 Roller body

(35) 216 Journal bush

(36) 218 Contact surface

(37) 220 Chock

(38) 222 Bearing bush

(39) 225 Wall areas of the groove

(40) 228 Pin

(41) 230 Groove

(42) 240 Perforated disk

(43) 245 Screw

(44) 300 Annular gap or lubricant space of the bearing

(45) 320 Lubricant

(46) 330 Lubricating film

(47) a Width of the ring seal in the axial direction

(48) A Width of the groove in the axial direction

(49) DD Outer diameter of the ring seal

(50) DZ Outer diameter of roll journal, if applicable with journal bush

(51) dD Inner diameter of the ring seal

(52) R Axial direction

(53) FR Radial pressing force on the seal

(54) FW.sub.max Maximum rolling force.