Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C13/00—Rolls, drums, discs, or the like; Bearings or mountings therefor
  • F16C13/02—Bearings
  • F16C13/022—Bearings supporting a hollow roll mantle rotating with respect to a yoke or axle
  • F16C13/024—Bearings supporting a hollow roll mantle rotating with respect to a yoke or axle adjustable for positioning, e.g. radial movable bearings for controlling the deflection along the length of the roll mantle
  • F16C13/026—Bearings supporting a hollow roll mantle rotating with respect to a yoke or axle adjustable for positioning, e.g. radial movable bearings for controlling the deflection along the length of the roll mantle by fluid pressure
  • F16C13/028—Bearings supporting a hollow roll mantle rotating with respect to a yoke or axle adjustable for positioning, e.g. radial movable bearings for controlling the deflection along the length of the roll mantle by fluid pressure with a plurality of supports along the length of the roll mantle, e.g. hydraulic jacks
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B27/00—Rolls, roll alloys or roll fabrication; Lubricating, cooling or heating rolls while in use
  • B21B27/02—Shape or construction of rolls
  • B21B27/03—Sleeved rolls
  • B21B27/05—Sleeved rolls with deflectable sleeves
  • B21B27/055—Sleeved rolls with deflectable sleeves with sleeves radially deflectable on a stationary beam by means of hydraulic supports
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
  • D21G1/00—Calenders; Smoothing apparatus
  • D21G1/02—Rolls; Their bearings
  • D21G1/0206—Controlled deflection rolls
  • D21G1/0213—Controlled deflection rolls with deflection compensation means acting between the roller shell and its supporting member
  • D21G1/022—Controlled deflection rolls with deflection compensation means acting between the roller shell and its supporting member the means using fluid pressure

Definitions

• the invention relates to a rotary envelope cylinder of the type consisting of a cylindrical tubular envelope rotatably mounted around an elongated support on which it is supported by means of a set of holding elements. and applies especially to the production of a support cylinder in a rolling mill of metal strips, in particular of steel.
• cylinders with rotating casing comprising a fixed support shaft in the form of an elongated beam, surrounded by a tubular envelope rotatably mounted around bearings defining an axis of rotation transverse to the rolling axis, and bearing on the beam by means of a series of holding means distributed one next to the other along the length of the beam and centered on an axial support plane which passes through the axis of the cylinder and a support generator, and corresponds to the plane of transmission of the clamping force when the cylinder is part of a rolling mill.
• each means of holding the envelope is constituted by a shoe centered substantially in the support plane, interposed between the envelope and the support beam and mounted sliding on the latter in a radial direction extending substantially. in the axial plane of the clamping force.
• Each shoe is supported, on one side on the internal face of the casing, by means of a cylindrical bearing face and on the other on the support beam, by means of a means of adjustable thrust generally consisting of at least one hydraulic cylinder interposed between the support beam and the shoe.
• ⁇ it is thus possible to individually adjust the thrust of each shoe in the radial direction to give the envelope the suitable profile and / or correct the distribution of the thrust forces along the support generator.
• the tubular envelope rotates while resting on all of the holding pads and it is therefore necessary to introduce a lubricating fluid between the bearing face of each pad and the internal face of the envelope.
• each retaining shoe can be provided, on its bearing face, with at least one hydrostatic pocket consisting of a recess opening towards the outside and supplied with a lubricating fluid under a pressure corresponding to the pushing effort.
• the hydrostatic pocket opening towards the outside, the lubricating fluid introduced into it under pressure can escape on the edges of the pocket, forming a lubricating film in the interval between the bearing face of the pad and the envelope.
• This leakage rate remains fairly low as long as the external face of the shoe is well centered relative to the cylindrical internal face of the rotary casing, but the latter is subjected to forces which can deform it transversely by causing the shoe to shift and , therefore, an increase in leakage rate.
• document GB-A-2 060 822 provides for adding to the thrust cylinders exerting the main force in the center of the shoe, two lateral cylinders in which the pressure can be varied so as to restore concentricity skate with the envelope.
• the width of the shoe, in the transverse direction, is then slightly increased but, the angular sector covered by the circular bearing face does not exceed 45 °. It is quite difficult, in this case, to maintain the stability of the skate which, most often, must be connected to the support beam by an articulated rod in order to remain centered on the axial plane passing through the bearing generatrix of the 'envelope.
• the lubricating fluid supplying the hydrostatic force pocket is simply taken from that which feeds the cylinder exerting the thrust force through a channel formed between the chamber of the cylinder and the hydrostatic pocket.
• Such a feeding mode could be suitable when such devices were used, for example, in the paper industry.
• Another advantage of this arrangement lies in the fact that the lubricating fluid is no longer supplied from the chamber of the thrust cylinder but by a separate circuit and under low pressure. It is therefore no longer necessary, as previously, to ensure a leakage rate in the high pressure circuit supplying the thrust cylinders.
• each shoe which, as indicated above, must cover a large angular sector, therefore has the shape of an elongated rectangle of rather small width compared to its length. This results in significant leaks on the lateral edges of each shoe and, consequently, a pressure drop with the risk of rupture of the lubricating film.
• the hydrodynamic lift effect created by the circulation of the oil in the interval between the shoe and the envelope therefore develops in a pressure zone comprising in the longitudinal direction of circulation of the fluid, an upstream part of progressive increase of the fluid pressure from the inlet of the shoe, a central part of hydrodynamic lift and a downstream part of rapid reduction of the pressure at the outlet of the shoe.
• the central lift part covers an angular sector of the shoe subjected to a pressure sufficient to compensate for the overall bearing force exerted on the tubular casing by the working cylinder.
• the object of the invention is to remedy these drawbacks by means of a relatively simple arrangement which makes it possible to better control the supply of oil to the hydrodynamic film and the distribution of the pressure on the bearing face of each pad and, thus, to more easily maintain relatively stable operating conditions.
• the invention therefore relates, in general, to a rotating envelope cylinder comprising a tubular envelope rotatably mounted around a fixed support in the form of an elongated beam and bearing thereon by means of a plurality of pads each having a cylindrical bearing face substantially of the same radius as that of the inner face of the envelope, the position and the thrust of each pad can be adjusted by means of a hydraulic cylinder bearing on one side on the beam and the other on the pad and supplied with pressurized fluid, each pad being, moreover, provided with a hydrostatic pocket formed in a middle part of its bearing face and supplied with pressurized fluid and, on the other hand, associated with means for introducing a lubricating fluid upstream of the gap between the bearing face of the shoe and the internal face of the casing, in order to create a hydrodynamic lift effect in a zone of pressure stretches ant on an angular sector of large opening and comprising, in the direction of rotation of the envelope, an upstream part of progressive increase in pressure, a central part of lift and a downstream part of
• each shoe is provided with two side pockets opening, respectively, on either side of the middle pocket, and supplied with fluid under sufficient pressure for introduction, in the entrained film, with an additional flow of fluid with local pressure increase, so as to widen upstream and downstream the angular sector covered by the central hydrodynamic lift part of the skate, thereby improving the stability of the latter.
• each pocket of each shoe is associated with a means for calibrating the flow introduced by the pocket considered, the pressure in said pocket being adjusted to a level at least sufficient to ensure the evacuation of the flow calibrated at the corresponding level of the fluid film, up to a maximum value of the thrust force exerted by the pad • on the envelope.
• the central bearing part of the pressure zone comprises a central bearing at high pressure extending over an angular sector corresponding substantially to the central pocket, and two lateral bearings each extending over an angular sector corresponding to a side pocket, respectively an upstream bearing with pressure lower than that of the central bearing and a downstream bearing with pressure comprised between that of the central bearing and that of the upstream bearing.
• each middle pocket of a shoe is supplied individually by a pump delivering a calibrated flow and the side pockets of all the shoes placed on the same side of the middle pocket are fed in parallel from the same pipe connected to the same pump on which are connected in parallel a plurality of individual supply lines of each pocket, each provided with a member for calibrating the flow rate of fluid introduced by said pocket into the driven film.
• the cylinder comprises at least three assemblies consisting, respectively, of pockets placed on all of the pads in the same position relative to the support plane, respectively upstream lateral, median and downstream lateral and the pockets of each all are supplied in parallel from a common pipe formed along the support beam and on which are branched a plurality of individual supply lines, respectively from each pocket of the assembly, each provided with a member individual flow calibration in the corresponding pocket.
• a rotating envelope cylinder according to the invention can be used, either in a tandem rolling mill in which the product always travels in the same direction, or in a reversible rolling mill operating in both directions of travel.
• the middle pocket of each shoe is centered in a radial plane slightly offset angularly downstream, in the direction of rotation, relative to the plane d 'support.
• the downstream side pocket advantageously covers an angular sector substantially double the sector covered by the upstream side pocket.
• the middle pocket is centered in the support plane P and the side pockets are symmetrical with respect thereto.
• the flows calibrated in the two side pockets can be equal and the flow calibrated in the middle pocket is advantageously of the order of twice the flow in each side pocket.
• Figure 1 is an overall diagram, in cross section, of a cylinder according to the invention applied to a rolling mill.
• Figure 2 is a detail view, in cross section, of a holding pad with its hydraulic circuits.
• Figure 3 is a bottom view of a holding pad.
• Figure 4 is a longitudinal sectional view of the cylinder, on which the oil supply system is schematically represented.
• Figure 5 is a three-dimensional diagram showing the evolution of the pressure along the bearing face of a shoe.
• FIG 1 there is shown schematically, in cross section and by way of example, a rolling mill of the quarto type comprising two working rolls T, T ′ between which the rolled product M passes and bearing respectively on the side opposite the product , on two support cylinders S, S 'between which is applied a clamping force directed along a support plane P which passes substantially through the axes of the cylinders.
• At least one of the support cylinders for example the upper support cylinder S consists of a tubular casing 1 rotatably mounted at its ends, by means of bearings A, A 'shown schematically in Figure 4, on a support beam 11 extending inside the tubular casing 1, transverse to the rolling direction, said bearings A, A 'defining the axis x'x of rotation of the casing.
• the tubular casing 1 is supported on the beam 11 by means of a plurality of retaining pads 3 distributed over its entire length and interposed between the cylindrical internal face 13 of the casing and a lower face 12 of the support beam 11.
• Each retaining shoe 3 is provided, on the side of the tubular casing 1, with a cylindrical bearing face 31 of diameter slightly smaller than that of the internal face 13 of the casing and bears on the underside 12 of the beam 11 by means of at least one hydraulic cylinder 2 which, in the example shown, comprises a piston 22 resting on the beam 11 and entering a recess 33 formed on the face 32 of the pad 3 facing the beam 11 and constituting the chamber of the hydraulic cylinder 2.
• the latter is supplied with fluid from a hydraulic unit H] by a high pressure supply circuit, connected to each of the skates by u no pipe 21 passing through the beam 11 and the piston 22 to open into the chamber 33 of the corresponding jack.
• Screed pad 3 is thus associated with a jack 2 supplied by a particular circuit 20, 21 whose flow and pressure can be controlled by a system, of regulation, according to information transmitted by devices of thickness control and of the profile or flatness of the rolled product M.
• a system of regulation, according to information transmitted by devices of thickness control and of the profile or flatness of the rolled product M.
• a detailed description of the apparatus and of the hydraulic system does not seem necessary, installations of this kind having already been carried out and described in published documents.
• such a system makes it possible, by controlling the position and the pressure of each jack 2, to adjust the profile of the support generator as well as the distribution of the thrust forces applied along it, especially to compensate for the bending of the beam- support 11 and correcting defects in thickness or flatness detected downstream on the laminated strip M.
• each shoe 3 is usually provided with a hydrostatic pocket centered substantially in the support plane P and supplied with pressurized oil, said pocket opening widely towards the internal face 13 of the tubular envelope of so as to form a lubricating film 4 between the internal face 13 of the casing 1 and the bearing face 31 of the shoe 3.
• the bearing face 31 of the shoe 3 covers a circular sector of very large angular opening greater than 45 °, which can even exceed 90 ° and, preferably, of the order of 100 or 110 °.
• Such a hydrostatic central pocket is advantageous, even at high speed because the fluid thus supplied in the central part of the shoe can mix with the film entrained by hydrodynamic effect if the supply pressure is greater than the pressure reached by hydrodynamic effect at this central pocket 5. It is thus possible to widen the pressure zone at the level of the central pocket in the longitudinal center of rotation as in the transverse direction.
• the pressure zone then comprises, from the entry of the shoe, an upstream part of progressive increase in pressure, a central part forming a maximum pressure level at the level of the central pocket 5 and a downstream part of rapid decrease pressure at the outlet of the skate.
• the hydrodynamic lift effect achieved by entraining the oil film 4 allows the skate to self-center because closing the gap at the outlet increases the pressure by wedge effect and, therefore, tends to center the envelope in relation to the skate.
• the leakage rate also tends to increase and there is a risk of rupture of the oil film with contact between the shoe and the casing. This therefore results in a risk of instability which, according to the invention, will be eliminated by introducing an additional flow of oil under pressure upstream and downstream of the central pocket 5 so as to widen the angular sector covered by the part central hydrodynamic lift of the skate. To this end, as shown in FIGS.
• the bearing face 31 of the shoe is provided, on either side of the central pocket 5, with two lateral pockets respectively downstream 6 and upstream 7 and each pocket 5 , 6, 7 is associated with a means of calibrating the flow introduced by this pocket under a pressure adjusted to a value at least equal to the hydrodynamic pressure at this level to allow the discharge of the calibrated flow in the fluid entrained by the rotation of the envelope.
• the oil injected into the three pockets 5, 6, 7 separated from one another is distributed by forming a continuous film practically over the entire angular sector covered by the bearing face 31, of the as shown schematically in Figure 5.
• FIG. 1 schematically shows an embodiment of the oil supply system of each shoe 3.
• the thrust jacks 2 associated respectively with each shoe 3 are supplied with fluid under high pressure, from a hydraulic unit H x , by a circuit 20, 21 opening into the chamber 33 of each jack 2.
• the hydrostatic pockets 5, 6, 7 are supplied, respectively by pipes 51, 61, 71, from a second hydraulic unit H 2 .
• oils having different viscosities depending on the use. Indeed, to facilitate the operation of the servo-valves
• FIG. 1 schematically shows a first embodiment of the circuits 8a, 8b for supplying pressure to the pockets 5, 6, 7.
• the lubricating fluid is supplied from the tank 80 by a pump 83 providing a fixed flow rate, controlled by a flow controller 88 with return to the tank by a weir system comprising an adjustable permanent leakage device 84.
• the three pockets 5, 6, 7 of each shoe are supplied under pressure, each by a pipe respectively 51, 61, 71 provided with a calibrator-flow regulator 52, 62, 72 making it possible to ensure, in service, the introduction of oil into each pocket with a flow regulated to a substantially constant value.
• the pressures in each of the supply circuits 51, 61, 71 are determined so as to ensure the evacuation of this calibrated flow of oil in each pocket, up to a maximum value of the thrust force likely to be applied to the envelope, taking into account the dimensions of the pocket. As indicated, a certain amount of oil escapes through the side edges of the pads, but most of it is discharged at the rear end of each pad.
• the cylinder is provided with a recovery device which extends over the entire length of the envelope, above the downstream ends of all the pads, to recover the oil which escapes from the pads and return it, via a return circuit 86, to the hydraulic unit Ff 2 .
• FIG. 4 which is a simple schematic view, in axial section, the pads 3 have been shown with a rotation of 90 ° to show the supply circuits of the three pockets which, in reality, are centered in the same transverse plane at axis.
• the adjacent pads 3 distributed over the entire length of the envelope are produced in the same way and therefore each comprise at least three pockets, respectively upstream lateral 7, median 5, and downstream lateral 6, which are placed in the same position. relative to the support plane P. It is therefore particularly advantageous to group the corresponding pockets into at least three sets, respectively downstream lateral E 2 , median Ej and lateral upstream E 3 , the pockets of each set being supplied in parallel from of a common pipe extending along the support beam 11. As shown in FIG. 2, these common pipes can be drilled in the support beam 11, parallel to the axis of rotation x'x or else be formed established pipes on the side of the beam 11.
• the two sets of pockets may advantageously be food s under the same pressure from the same pipe 60.
• the beam 11 is provided with three axial pipes, respectively 20 for supplying the push cylinders 2, 50 d feeding the middle pockets 5 and 60 supplying the upstream side pockets 7 and downstream 6.
• pipes 51a, 61a, 71a drilled transversely in the support beam 11 and connected in derivation, respectively on the supply pipe 50 for the assembly Ei of the middle pockets 5 and on the line 60 for supplying the assemblies E 3 , E 2 of the upstream side pockets 7 and downstream 6.
• the transverse pipes 51a, 61a, 71a are connected, respectively, by flexible pipes 51b, 61b, 71b, each to a corresponding pipe 51c, 61c, 71c pierced in the shoe 3 and opening, respectively, at one end on a lateral side of the shoe 3 and at the other end in the corresponding pocket 5, 6, 7.
• each individual circuit 51abc, 61abc, 71abc is provided with a calibrator 52, 62, 72 arranged, for example, on the beam 11, at the outlet of the transverse pipe 51a, 61a, 71a, and which makes it possible to regulate the introduction of oil into the corresponding pocket 5, 6, 7, while maintaining a substantially constant outlet flow.
• the common pipes 20, 50, 60 are drilled longitudinally in the support beam 11 but could also be fixed to the side of the beam.
• the chamber 33 of the thrust cylinder of each shoe 3 is supplied with oil under high pressure and low viscosity from the first hydraulic power station Hj by a circuit 20 which, can advantageously pass through a longitudinal bore of the beam 11.
• a such a circuit, comprising means for individual adjustment of each shoe 3 in position and pressure, is well known and has therefore not been described or shown in detail in the drawings.
• the hydraulic unit H 2 also includes a booster pump 87 for the introduction of oil to low pressure at the inlet 34 of the shoe 3.
• the oil introduced by the side pockets 6, 7 is obviously _ of the same kind and mixes with the lubricating film 4 driven by the rotation of the envelope.
• Each pump 83a, 83b is associated with a flow controller 88a, 88b, with weir 84a, 84b. In this way, if the hydrodynamic pressure in the film 4 is sufficient at each point to ensure lift, taking into account the forces applied, the oil supplied by the pumps 83a, 83b is returned to the tank.
• the calibrated flow rate is delivered by the corresponding pocket and mixes with entrained fluid to compensate for leaks and increase pressure.
• the rolling mill is designed to operate over a certain range of force and the supply pressures in the common conduits 50, 60 as well as the calibrated flow rates introduced into each pocket 5, 6, 7 by the individual circuits 51, 61, 71 are determined so as to ensure the evacuation of the oil and the formation of a continuous film over the entire range of adjustment of the thrust force exerted on each of the pads by the jack 2, up to at a maximum value which depends on the conditions of use and on parameters such as, in the case of the rolling of a sheet, the width and thickness thereof, the temperature and the characteristics of the metal, as well as the rate thickness reduction to be achieved.
• FIG. 4 schematically shows such an embodiment comprising a pumping assembly 9 comprising as many pumps 91 as there are pads 3, each pump 91 supplying the middle pocket of a pad at the pressure necessary for the evacuation of the calibrated flow taking into account of the thrust force applied to the casing 1 at the level of the pad considered.
• the two sets E 2 , E 3 of side pockets can be supplied by means of the same pump 83 by a circuit 8 similar to that which has just been described with reference to FIG. 1.
• this circuit 8 may include, downstream of the pump 83, a safety block 84 which limits the common pressure to the desired level and a member 88 for measuring and controlling the overall flow in the two sets E 2 , E 3 of side pockets 3 of the pads 3.
• the upstream side pocket 7 covers an angular sector of approximately 10 °, its median plane PI being inclined by approximately 25 ° relative to the support plane P on which is centered.
• the median pocket 5, and the median plane P2 of the downstream pocket 6 which also covers a sector of approximately 10 °, is inclined by approximately 20 ° relative to said vertical support plane P.
• the median pocket 5 is centered on the support plane P and covers an angular sector of approximately 20 °.
• the pad remains, however, of the type shown in Figure 2 and therefore comprises means for introducing, at the inlet 34 of the pad, a lubricating fluid which is driven by the rotation of the casing 1 and achieves an effect hydrodynamic lift.
• the pressure diagram therefore comprises, as usual, an upstream zone A of progressive increase in the pressure of the fluid, a central zone B of maximum pressure and a downstream zone C of rapid reduction of the pressure at the out of the skate.
• the two side pockets 7, 6 substantially modify the shape of the parts A and C of the diagram by forming in them two pressure stages, respectively upstream 41 and downstream 42, on either side of a central bearing 40 corresponding to the middle pocket 5.
• the oil introduced at low pressure at the inlet 34 of the shoe being gradually driven its hydrodynamic pressure is not very high at the upstream pocket 7 and can be, for example, in the example shown, of the order 1/7 of the maximum pressure in the middle pocket 5.
• the introduction, at this level, of an additional flow of fluid which mixes with the lubricating film driven by the rotation increases the pressure of the latter allows '' widen upstream the upstream part A of the lift zone.
• the width L 2 of the shoe is small compared to its length Lj, lateral oil leaks occur and the zone of maximum pressure tends to narrow in the direction of rotation of the envelope.
• the pressure in the downstream pocket 6 can be of the order of half of the maximum pressure in the middle pocket 5.
• the angular sector covered by the hydrodynamic lift zone is widened upstream and towards the 'downstream.
• the introduction of a pressurized fluid into the two lateral pockets 6, 7 produces, by hydrostatic effect, thrust forces Fi, F 2 centered on the radial median planes Pi, P 2 of the two pockets 6, 7 which are inclined at an angle of at least 20 ° relative to the support plane P. Thanks to this increase in the angular sector of hydrodynamic lift and to this support of the envelope at three separated points, the stability of each shoe is considerably improved.
• the support cylinder can thus receiving sudden variations in the thrust force applied by the working cylinder without risk of decentering the casing 1 and of -contact between it and the external faces 13 of the pads 3.
• the invention does not is not limited to the details of the embodiments which have just been described by way of simple example and could be subject to variants without departing from the protective framework of the invention.
• the hydrodynamic lift zone must, however, cover a large angular sector, of the order of a quadrant and, in any case, at least 45 ° to 50 °.
• the median plane P Î of the downstream pocket 6 is more inclined with respect to the support plane P than the median plane P 2 upstream pocket 7.
• the middle pocket 5 could be slightly offset downstream, in the direction of rotation of the casing 1 to compensate for the deformation in the opposite direction of the associated working cylinder, during the passage of the product. .
• the median plane P of the median pocket 5 would be slightly inclined relative to the vertical.
• the present invention can also advantageously be applied to the production of reversible rolling mills in which the rolls and, consequently, the tubular casing 1 rotate alternately in one direction and in the other.
• the arrangement would be symmetrical, the middle pocket 5 being centered on the vertical plane passing through the axis and the two side pockets 6 and 7 being equal and centered on planes inclined at the same angle relative to the vertical , on both sides of it.
• the reference signs inserted after the technical characteristics mentioned in the claims are intended only to facilitate the understanding of the latter and in no way limit their scope.

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• 2004
  • 2004-04-16 EP EP04742534A patent/EP1740326A1/de not_active Withdrawn
  • 2004-04-16 US US11/547,723 patent/US20080125297A1/en not_active Abandoned
  • 2004-04-16 WO PCT/FR2004/000954 patent/WO2005110635A1/fr not_active Application Discontinuation
  • 2004-04-16 CN CNB2004800427571A patent/CN100546733C/zh not_active Expired - Fee Related

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