TW202214364A - Backup roll unit for tension leveler - Google Patents

Abstract

Provided is a backup roll unit that suppresses increases in rotational torque and leakage of lubricant in a structure in which a solid lubricant is sealed in a ball bearing supporting a backup roll. The backup roll unit 1 is for a tension leveler in which a ball bearing 2 rotatably supporting a roll 4 with respect to a shaft 3 is arranged between the roll 4 and the shaft 3. The ball bearing 2 has an inner race 5 and an outer race 6 which are bearing rings, a plurality of balls 8 interposed between the inner race 5 and the outer race 6, and a holder 7 for holding the balls 8. A solid lubricant 9 is sealed in the bearing interior space of the ball bearing 2, and the total volume of the solid lubricant 9 is 30-40% of the volume of the bearing interior space.

Description

Back idler unit for tension leveler

The present invention relates to a backing roll unit for supporting work rolls or intermediate rolls in a tension leveler device. Especially with regard to the back roller unit that uses ball bearings to support the back roller.

In iron and steel manufacturing equipment, in the final stage of the rolling process of metal materials, in order to correct the shape defects (warping, undulation) of metal sheets and metal strips, a tension leveler device is used. This tension leveler device can be used alone or assembled in other devices as part of other devices.

FIG. 4 shows an example of a tension leveler device. Fig. 4 is a schematic view of an apparatus for correcting shape defects of a metal sheet in the final stage of the rolling process. As shown in FIG. 4 , roll units 23 are arranged vertically with respect to the metal sheet 22 being processed, and the metal sheet 22 is passed between the work rolls 24 of the upper and lower roll units 23 to apply a tensile force to the metal sheet 22 Rolling is performed. The upper and lower roll units 23 apply a compressive force to the metal plate 22 in the direction of the metal plate. The work rolls 24 and the intermediate rolls 25 rotate with the movement of the metal plate 22 , and the backing rolls 26 are subjected to loads in the radial direction. Rolling is performed by the work rolls 24 reinforced by the backing rolls 26, so that the elongation of the metal sheet 22 is produced by several %. In addition, the tension leveler device 21 is also provided with a plurality of deflection rollers 27 for supporting the metal plate 22 and capable of changing the direction. Since a load sensor is provided inside the deflection roller 27, it can also be used as a shape detection roller for detecting whether the metal plate 22 is skewed or warped.

The back roller is based on: different types of metal plate materials, different radial loads and required torques according to the conditions of use, and have different specifications. If the radial load is large, in order to make a structure with a high load capacity, a back roller unit is used which has a roller bearing for supporting the radial load and a ball bearing for supporting the axial load. . For example, the backing roller unit disclosed in Patent Document 1 is used to rotatably support the roller in the bearing on the shaft, as the bearing for radial load load, which is tied at about the middle position in the axial direction of the roller. Needle bearings are installed at two places along the axial direction, and ball bearings are installed at one of the ends on the outer side in the axial direction of the rollers as thrust load bearings.

On the other hand, if the radial load is small and only low torque is needed, it is to use the back roller unit that only uses the ball bearing to support the back roller. In this type of backing roller unit, deep groove ball bearings are provided between the shaft and the rollers on both sides in the axial direction along the axial direction. This kind of back idler unit only uses the pair of deep groove ball bearings to bear radial load and thrust load (ie, axial load), and does not additionally provide needle roller bearings (roller bearings) as radial loads. Bearings for heavy loads. By making it a structure supported only by deep groove ball bearings and lowering the torque, even when the frictional force with the work rolls or intermediate rolls is small, the slip phenomenon between the rolls can be suppressed.

In addition, when the above steps are performed using a tension leveler, in order to cool the rolled metal plate and to remove dust and foreign matter adhering to the metal plate, the cleaning solution is continuously sprayed on the metal plate. The backing rollers, which reinforce the work rolls, also get wet with a large amount of cleaning fluid. In order to prevent the lubricant inside the bearing from flowing out to the outside of the bearing due to the intrusion of the cleaning liquid, this back roller is provided with a sealing structure to prevent the cleaning liquid from entering the inside of the bearing. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2013-146749

[Problems to be Solved by Invention]

As described above, this structure does not have a roller bearing inside, but only uses a deep groove ball bearing to support the radial load and the axial load. By reducing the torque, even the friction between the work roll and the intermediate roll is reduced. Even when the force is small, the slippage between the rollers can be suppressed, and the occurrence of skew and warpage deformation can be suppressed. However, for example, when the object to be rolled is a metal sheet or metal strip whose elongation strength and surface hardness are lower than those of steel, such as aluminum, warping, wrinkles, and roll slippage are likely to occur. Traces (tiny streak marks). Therefore, it is expected that a more stable low torque can be achieved even in a structure in which radial and axial loads are supported only by deep groove ball bearings.

In addition, if the grease used as a lubricant leaks from the backing roller unit and adheres to the object to be rolled, it will cause warpage, wrinkles, and slip marks of the roll, and there may be problems due to insufficient lubricant. This leads to increased torque in deep groove ball bearings and the risk of premature wear.

The present invention has been developed in view of such a situation, and an object of the present invention is to provide a backing roller unit which is fastened to a structure in which a solid lubricant is encapsulated in a ball bearing for supporting the backing roller, and which can suppress rotation Torque rise and lubricant leakage. [Technical means to solve problems]

The backing roller unit for a tension leveler of the present invention is a backing roller unit for a tension leveling machine which is fastened between a roller and a shaft, and a backing roller unit for a tension leveler is arranged with a ball bearing that rotatably supports the roller on the shaft. Features are: The above-mentioned ball bearing is provided with an inner ring and an outer ring as a track wheel, a plurality of balls interposed between the inner ring and the outer ring, and a retainer for holding these balls, A solid lubricant is encapsulated in the bearing inner space of the ball bearing, and the total volume of the solid lubricant accounts for 30% to 40% of the volume of the bearing inner space. In particular, it is also a feature that there is no roller bearing inside the backing roller unit.

The above-mentioned retainer is a wave-shaped retainer in which a pair of annular bodies are joined together by connecting portions between the ball nests for holding the above-mentioned balls, and the above-mentioned solid lubricant is tied between the above-mentioned balls. It is also a feature that it is fixed to the connecting portion of the above-mentioned retainer.

The above-mentioned solid lubricant is also characterized in that it is a cured product of a mixture of a resin component and a lubricating component. In addition, the above-mentioned resin component is an ultra-high molecular weight polyolefin, and the above-mentioned lubricating component is a grease containing a base oil and a thickener, which is also a feature.

It is also a feature that the above-mentioned ball bearing includes a seal plate fixed to one of the inner ring and the above-mentioned outer ring, and there is a gap between the seal plate and the other of the ring rollers. [Effect of invention]

The backing roller unit for a tension leveler of the present invention is a backing roller unit formed by disposing a ball bearing between the roller and the shaft, wherein a solid lubricant is encapsulated in the inner space of the bearing tied to the ball bearing, The total volume of this solid lubricant is 30% to 40% of the volume of the bearing inner space, and therefore, the increase in sliding resistance caused by the solid lubricant can be suppressed, and the increase in torque can be suppressed. That is, by setting the total volume of the solid lubricant to 40% or less of the volume of the inner space of the bearing, the solid lubricant can be arranged between the balls and the space between the inner and outer rings and the seal plate can be reduced. sliding area. In addition, by setting it to 30% or more, the absolute content of the lubricating component contained in the solid lubricant can be ensured, and the solid lubricant can be fixed by wrapping the solid lubricant on the retainer, and the solid lubricant can be suppressed. The movement in the bearing can be prevented, and the solid lubricant can be prevented from being drawn into the rolling surface.

In addition, the structure of the retainer adopts a wave-shaped retainer composed of a pair of annular bodies connected by connecting portions between ball nests for holding the balls, and a solid lubricant is wrapped around the balls between the balls. It is possible to hold the solid lubricant on the cage connecting portion between the balls and prevent the solid lubricant from being drawn into the rolling surfaces.

In addition, since the solid lubricant is a solidified product of a mixture of the resin component and the lubricating component, the solid lubricant can be surely fixed to the retainer. For example, by wrapping a semi-solid lubricant (a mixture of a resin component and a lubricating component) around a retainer and molding it at room temperature, and then thermally hardening it, it is possible to obtain: A structure that does not easily fall off or flow out of solid lubricants when wet with liquid and dew condensation water.

In addition, in the ball bearing, a seal plate fixed to one of the inner and outer races is provided, and a gap is maintained between the seal plate and the other raceway, so that As a result, it is possible to suppress an increase in torque due to the seal plate, and heat generation and temperature increase in the bearing portion, and it is also possible to suppress premature bearing wear due to deterioration of the solid lubricant.

Combining these results, the present invention can provide a backing roller unit with a longer service life without compromising the low torque performance of the ball bearing. In particular, it is especially suitable for the back bracket of the structure that does not have a roller bearing (needle roller bearing) in the interior where the radial load is small and low torque is required, and only uses the ball bearing to support the radial load and the axial load roller unit.

The tension leveler device to which the back roller unit of the present invention is applied is a conventional tension leveler device described with reference to FIG. 4 and the like. This type of device is used to correct shape defects (warping, undulation) of metal sheets and metal strips in iron and steel manufacturing facilities, and is used in the final process of rolling or after rolling. This kind of device, in addition to being used alone, is sometimes used in combination with devices such as surface coating equipment and cutting equipment.

As shown in FIG. 4 , in the tension leveler device 21 , the metal plate 22 is stretch-rolled by the work rolls 24 reinforced by the backing rolls 26 . The back roller unit for a tension leveler of the present invention is a unit composed of a back roller, a shaft of the roller, and a ball bearing interposed between the shaft and the roller. This type of back roller unit is used in an environment where it comes into contact with a large amount of liquid, such as cleaning liquid, in the equipment.

Hereby, an embodiment of the backing roller unit for a tension leveler of the present invention will be described with reference to FIG. 1 to FIG. 3 . Fig. 1 is a perspective view of such a back idler unit, which shows a view with a part of the member (half of the front part of the roller) cut away and removed. FIG. 2 is an enlarged view of one end portion of the roller of FIG. 1 , and FIG. 3 is a front view of FIG. 2 . As shown in FIG. 1 , the backing roller unit 1 has a structure in which a ball bearing 2 for rotatably supporting the roller 4 on the shaft 3 is arranged between the roller 4 and the shaft 3 . The ball bearings 2 are provided at both ends of the roller 4 in the axial direction, respectively, and are used as a pair of ball bearings 2 . In addition, the "axial direction" referred to in the present invention refers to the direction along the axis of the shaft 3, and the "radial direction" refers to the radial direction with the axis of the shaft 3 as the center. The material of the roller 4 and the shaft 3 can be various steel materials, for example, the roller 4 is made of bearing steel, and the shaft 3 is made of carbon steel.

The backing roller unit 1 of the form shown in FIGS. 1 to 3 does not have a roller bearing (needle roller bearing) inside, but uses a ball bearing 2 to support the radial direction applied to the roller 4 load and axial load. Therefore, compared with the backing roller unit with a roller bearing (needle roller bearing) inside, the torque is lower and the radial load is smaller, so it is suitable for use in applications requiring low torque.

The shaft 3 is a shaft body formed with a step portion, and has a shaft main body portion formed in the middle portion in the axial direction, and shaft end portions provided at both ends in the axial direction. The shaft end of the shaft 3 protrudes to the outside of the roller 4 . In addition, the shaft 3 is inserted into the roller 4 with a gap in the radial direction. A pair of ball bearings 2 are arranged between the shaft body portion of the shaft 3 and each shaft end portion.

The roller 4 has a cylindrical shape, and ball bearings 2 are arranged at both ends in the axial direction. Furthermore, for the purpose of preventing foreign matter (eg, foreign matter such as water) from entering the inside of the roller 4, cover plates 11 are provided outside the ball bearings 2 at both ends of the roller 4 in the axial direction. The cover plate 11 is fixed on the shaft 3 .

As shown in FIGS. 2 and 3 , the ball bearing 2 is a deep groove ball bearing. The inner ring 5 and the outer ring 6 of the track wheel are arranged concentrically, and a plurality of ball bearings are arranged between the inner and outer ring rolling surfaces. Ball 8. The retainer 7 is provided with a plurality of ball nests 7a for holding the balls 8 at equal intervals in the circumferential direction, and the balls 8 are held at equal intervals in the circumferential direction by the ball nests 7a. The materials of the inner wheel 5, the outer wheel 6 and the balls 8 can be used as bearing materials, and commonly used materials can be used, such as bearing steel, carbon steel, stainless steel, high-speed steel, etc. Further, as the ball bearing 2, in addition to a deep groove ball bearing, an angular contact ball bearing, a four-point contact type ball bearing, or the like can be applied.

The retainer 7 is a wave-shaped retainer that combines a pair of annular bodies by connecting portions 7b between the bead nests 7a. The annular body constituting the retainer 7 is provided alternately in the circumferential direction with a plurality of curved portions forming a curve along the balls 8 and a flat plate portion for connecting these curved portions. The pair of annular bodies are integrally formed by fixing the flat plate portion with a rivet or the like in a state in which the curved portion and the curved portion and the flat plate portion and the flat plate portion face each other. The overlapping portion of the flat plate portions becomes the connecting portion 7b. Each ring system is produced by stamping a metal sheet. As the metal plate, a material commonly used as a holding device can be used, and for example, cold-rolled steel sheet, carbon steel, etc. can be used.

The ball bearing 2 is provided with sealing plates 10 at the openings at both ends in the axial direction of the inner ring and the outer ring. The sealing plate 10 is composed of a disk-shaped core plate 10a made of cold-rolled steel sheet or the like, and a rubber portion 10b made of nitrile rubber or the like fixed to the core plate 10a. The outer peripheral portion of the seal plate 10 is fixed in the groove on the inner periphery of the outer ring 6, and a labyrinth-shaped gap is formed between the inner peripheral portion of the seal plate 10 and the groove on the outer periphery of the inner ring 5 (non-contact seal) . The provision of the seal plate 10 can prevent the cleaning liquid or the like that has penetrated through the cover plate 11 from directly intruding into the bearing, and the deterioration and outflow of the solid lubricant can be suppressed. In addition, since a solid lubricant is used, and a labyrinth-shaped gap is provided in the seal plate 10, the rotational torque can be reduced, and the outflow of the lubricating component can be suppressed.

In addition, the structure of the sealing plate 10 is not limited to this, For example, a metal sealing plate (without a rubber part) may be used. In addition, the sealing plate 10 may be installed only on one end of the ball bearing 2 , in particular, only on the end surface side of the roller 4 . Otherwise, for example, when the sealing plate 10 is fixed to the track wheel, it may be fixed to the inner wheel side.

The ball bearing 2 is encapsulated with a solid lubricant 9 in the inner space of the bearing. One of the characteristics of the present invention is that the total volume of the solid lubricant 9 enclosed in the bearing inner space is set to 30% to 40% of the volume of the bearing inner space. The "volume of the inner space of the bearing" referred to here refers to the space enclosed by the inner ring 5, the outer ring 6 and the sealing plate 10 (if only one side of the sealing plate is provided, it is up to the end face of the bearing) , the volume of the space after the balls 8 and the retainer 7 are removed. Also, the so-called "total volume of solid lubricants" refers to the total volume of solid lubricants in the inner space of the bearing, if the solid lubricants are separately packaged in a plurality of places (in the form of scattered points). package), the total volume of their locations.

If the total volume of the solid lubricant is less than 30%, the amount of lubricating components gradually released from the solid lubricant to the periphery of the rolling elements will be insufficient, and the increase in the rotational torque (especially the torque at start-up) cannot be sufficiently suppressed. There is also a fear that the solid lubricant will be separated from the retainer, and there will be a fear of insufficient lubricating components during long-term operation. Also, if the total volume of the solid lubricant exceeds 40%, the sliding area between the inner and outer wheels and the sealing plate can easily become too large, and the solid lubricant is easily drawn into the rolling surface, which may cause rotation. Fear of torque increase or change.

In the backing roller unit for a tension leveler of the present invention, there are cases in which cleaning fluid or the like flows into the inside of the bearing, and at this time, the cleaning fluid or the like comes into contact with the solid lubricant. By setting the total volume of the solid lubricant to 30% or more, the solid lubricant can be wrapped (wound) around the retainer and fixed, and movement and separation of the solid lubricant can be suppressed. In addition, the absolute amount of the lubricating component contained in the solid lubricant can be ensured, and the lubricating component can be prevented from becoming insufficient during long-term operation of the backing roller unit. In addition, by setting the total volume of the solid lubricant to 40% or less, as described above, it is possible to suppress the rise or fluctuation of the rotational torque even if the material of the metal sheet and metal strip to be rolled is stretched Even in the case of aluminum materials with lower strength and surface hardness than steel materials, the occurrence of warpage, wrinkles, and roll slip marks can be suppressed.

Next, the solid lubricant used in the present invention will be described. The type of the solid lubricant used in the present invention is not particularly limited, and examples thereof include (1) a cured product of a mixture of a resin component (including a substance that becomes a resin component after a chemical reaction) and a lubricating component. , (2) A solid lubricant that penetrates the lubricating component into the cured resin component. It is preferable to use the solid lubricant of (1) because it can hold a large amount of lubricating components and can be tightly fixed to a retainer or the like. Hereinafter, the solid lubricant is explained in detail as follows.

The resin component of the solid lubricant can be used: ultra-high molecular weight polyolefin, polyamide, polyacetal, fluorine-containing resin, silicone, polyurethane, polyolefin, polystyrene, polyvinyl chloride and other general-purpose plastics, Engineering plastics. These materials are powdered and mixed with lubricating components to form a mixture, and the mixture is cured (hardened) by heating or the like to obtain a solidified body.

Specific examples of ultra-high molecular weight polyolefins include powders of polyethylene, polypropylene, polybutene, or copolymers of these substances, or mixed powders obtained by adding individual powders of these substances. . The average molecular weight (average molecular weight measured by the viscosity method) of each powder here is preferably set to 1×10 ⁶ to 3×10 ⁶ . Polyolefins in this molecular weight range are superior to low molecular weight polyolefins in all aspects of stiffness and oil retention. In addition, among ultra-high molecular weight polyolefins, it is more preferable to use ultra-high molecular weight polyethylene.

Specific examples of polyamides include polyamide 11, polyamide 12, polyamide 46, polyamide 6, polyamide 6-6, polyamide 6-10, polyamide 6-12, polyamide MXD6, and the like. The fluorine-containing resins include polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and the like.

As the lubricating component of the solid lubricant, lubricating oil or grease can be used. The lubricating oil is not particularly limited, and paraffin-based or naphthenic-based mineral oils, ester-based synthetic oils, ether-based synthetic oils, hydrocarbon-based synthetic oils, fluorine oils, silicone oils, animal oils, and vegetable oils can be used. These oils can be used alone or as a blend. If the resin component and the lubricating oil cannot be dissolved or dispersed in each other due to chemical compatibility such as polarity, lubricating oil with similar viscosity can be used. This makes it easier to physically mix and prevent lubrication. Oil segregation.

Specific examples of the mineral oil include fluid paraffin oil, spindle oil, turbine oil, engine oil, generator oil, and highly refined oil. Specific examples of ester synthetic oils include diester oils such as dibutyl phthalate, di-2-ethylhexyl sebacate, dioctyl adipate, trioctyl, Aromatic ester oils such as tridecyl trilaurate. Specific examples of ether-based synthetic oils include alkylated diphenyl ether oils such as monoalkyl diphenyl ether oils, dialkyl diphenyl ether oils, and polyalkyl diphenyl ether oils. Specific examples of hydrocarbon-based synthetic oils include 1-octene, 1-nonene, 1-dodecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1- -Pentadecene, 1-hexadecene, 1-NONADECENE (trade name), 1-octadecene, 1-DOCOSENE (trade name), 1-Eicosene (trade name), 1-Docosene (trade name) ), 1-Tetradecene (trade name) and other oligomers composed of polyalpha-olefin oil (PAO oil). Specific examples of the fluorine oil include perfluoropolyether oil, oligomers of chlorotrifluoroethylene, and the like. Animal oils include silkworm chrysalis oil, beef trotter oil, lard (lard fat), sardine oil, herring oil, and the like. Vegetable oils include camellia oil, olive oil, peanut oil, castor oil, rapeseed oil, and the like.

Grease is formed by adding a thickener to base oil, and the above-mentioned lubricating oil can be used as the base oil. Specific examples of the thickener include soaps such as lithium soap, lithium complex soap, calcium soap, calcium complex soap, aluminum soap, and aluminum complex soap, and urea compounds such as diurea compounds and polyurea compounds.

For example, a diurea compound can be obtained by reacting a diisocyanate with a monoamine. The diisocyanates include phenylenediisocyanate, biphenyldiisocyanate, phenylenediisocyanate, diphenylmethanediisocyanate, octadecanediisocyanate, decanediisocyanate, hexanediisocyanate, and the like. As the monoamine, octylamine, dodecylamine, hexadecylamine, octadecylamine, oleylamine, aniline, p-toluidine, cyclohexylamine, etc. are mentioned. The polyurea compound can be obtained, for example, by reacting diisocyanate with monoamine and diamine. Examples of diisocyanates and monoamines include the same diisocyanates and monoamines used for the production of the diurea compound, and examples of diamines include ethylenediamine, propanediamine, butanediamine, and hexanediamine. Alkane diamine, octane diamine, phenylenediamine, toluene diamine, xylene diamine, etc.

Lubricating ingredients may also contain: solid lubricants such as molybdenum disulfide and graphite; friction modifiers such as organic molybdenum; oily agents such as amines, fatty acids, greases, etc.; antirust agents such as petroleum sulfonate, dinonylnaphthalene sulfonate, sorbitol ester; extreme pressure agents such as sulfur series and sulfur phosphorus series; wear inhibitors such as organic zinc and phosphorus series ; Metal inactive agents such as benzotriazole and sodium nitrite; various additives such as viscosity index enhancers such as polymethacrylate and polystyrene.

In addition, solid wax may be added to the solid lubricant for the purpose of suppressing the oozing of oil and preventing the leakage of the lubricating component from the bearing during sintering. Examples of the solid wax include vegetable waxes such as carnauba wax and candelilla wax; animal waxes such as beeswax and insect ash; and petroleum waxes such as paraffin wax. The solid wax may contain the above-mentioned various waxes in the formulation of low molecular weight polyolefin or the like.

The following examples of solid lubricants A to E are used to show specific examples of combinations of the above-mentioned resin components and lubricating components, and methods of encapsulation (encapsulation).

[Solid lubricant A] The resin component in the solid lubricant A is ultra-high molecular weight polyethylene powder, and the lubricating component is a grease in which lithium soap is dispersed in mineral oil. This grease is first mixed homogeneously with UHMWPE powder. This fluid mixture is filled and sealed between the balls of the bearing and the balls in such a way that it is wrapped (wound) in the connection part of the cage, etc., and heated to a gel of ultra-high molecular weight polyolefin. Sintering is carried out at a temperature (melting temperature) above this point, and then the solid lubricant A is formed by cooling and solidifying (hardening). The method of mixing is not particularly limited, and for example, a general mixer such as a Henschel mixer and a ribbon mixer can be used. In addition, the heating and sintering conditions are preferably heated to a temperature higher than the above-mentioned gel point and lower than the dropping point of the grease. For example, when the average molecular weight of the ultra-high molecular weight polyethylene is 1×10 ⁶ to 3×10 ⁶ , heating at a temperature of 150 to 200° C. is suitable. The content of the ultra-high molecular weight polyethylene powder in the solid lubricant A is set to, for example, 20 to 50 mass % in the bulk solid lubricant.

[Solid lubricant B] As the resin component in the solid lubricant B, ultra-high molecular weight polyolefin powder is used, and as the lubricating component, one or more oils selected from the group consisting of free paraffin, PAO oil, vegetable oil and animal oil are used. In addition, as the lubricating component, a lubricating grease whose base oil is one or more kinds of oils selected from the group consisting of free paraffin, PAO oil, vegetable oil and animal oil is used. The packaging method, etc., is the same as that of the solid lubricant A. The content of the ultra-high molecular weight polyolefin powder in the solid lubricant B is, for example, 1 to 95% by mass in the bulk solid lubricant.

[Solid lubricant C] The resin component of the solid lubricant C is a combination of modified silicone oil and a hardener, and the lubricating component is a lubricating oil that is not compatible with silicone or uses this lubricating oil as its base oil. grease. As a hardening agent used, a bisphenol type epoxy compound and a cycloaliphatic epoxy compound are mentioned. By polymerizing the modified silicone oil and the hardener in the lubricating component, a three-dimensional mesh structure of silicone can be formed to maintain the structure of the lubricating component. The packaging method is the same as the solid lubricant A. First, a uniform mixture of modified silicone oil, hardener and lubricating ingredients is filled and packaged between the balls of the bearing and the joints of the retainer, etc., and then The solid lubricant C having the above-mentioned structure is obtained by heating and sintering at a predetermined temperature to harden it. The content of the resin components (modified silicone oil and hardener) in the solid lubricant C is, for example, 20 to 80% by mass in the entire solid lubricant.

[Solid lubricant D] As the resin component of the solid lubricant D, polyamide powder or polyacetal powder is used, and as the lubricating component, one or more oils selected from the group consisting of free paraffin, PAO oil, vegetable oil and animal oil are used. In addition, the lubricating component is a grease whose base oil is one or more kinds of oils selected from fluid paraffin, PAO oil, vegetable oil, and animal oil. The packaging method, etc., is the same as that of the solid lubricant A. The content of the resin component in the solid lubricant D is set to, for example, 1 to 95% by mass of the entire solid lubricant.

[Solid Lubricant E] The resin component in the solid lubricant E uses ultra-high molecular weight polyolefin powder, and the lubricating component uses a grease whose base oil is paraffin-based mineral oil, and contains solid wax. This solid wax is a solid wax that contains, in total, 13% by weight or more of ordinary paraffin wax components having a linear carbon number of 36 or more in the bulk solid wax. The above-mentioned ordinary paraffin component is preferably an ordinary paraffin component whose linear carbon number is between 30 and 33 in the mode value of the content rate in the linear carbon number distribution. The packaging method and the like are the same as those of the solid lubricant A. The content of the ultra-high molecular weight polyolefin powder in the solid lubricant E is, for example, 10 to 30 mass % in the bulk solid lubricant. In addition, the content of the solid wax is, for example, set to 1 to 10 mass % in the whole solid lubricant.

Examples of other solid lubricants include those obtained by reacting polyols with diisocyanates in the presence of lubricating components, or by adding urethane prepolymers having isocyanate groups in the molecule. A polyurethane-based solid lubricant obtained by reacting with a hardener in the presence of a lubricating component, and a solid lubricant obtained by further foaming the solid lubricant.

The above-mentioned solid lubricant is filled in the form of a mixture (solid lubricant material) of the resin component and the lubricating component before curing, and solidified inside the bearing. That is, the above-mentioned solid lubricant is a solidified body of a mixture of a resin component (including a substance that becomes a resin component after the reaction) and a lubricating component. Because the resin component is cured in the presence of the lubricating component, a large amount of the lubricating component can be retained, and the lubricating component (base oil in the grease) is slowly released during operation, so it can be maintained for a long time. Lubrication properties during the period. In addition, even if it comes into contact with a cleaning liquid or the like, the lubricating component does not easily flow out.

Although the filling and sealing (sealing) position of the solid lubricant is not particularly limited, the filling and sealing are preferably carried out by wrapping (winding) on the connecting portion of the corrugated holder. Specifically, a grease-like mixture having fluidity at room temperature before curing is wrapped around the connecting portion (the portion where the flat plate parts are butted together) and extends beyond the flat plate in the radial direction up and down. The parts are connected together to fill, and the mixture is solidified (hardened) to become a solid lubricant in the state of being wrapped (wound) in the connecting part. In this way, the solid lubricant can be surely fixed to the retainer, and even if it comes into contact with the cleaning liquid or is exposed to high temperature, it is not easily removed from the retainer. Furthermore, in the present invention, the encapsulated amount of the solid lubricant is, as described above, 30% to 40% of the volume of the bearing inner space, so it is not completely filled, but distributed in dots. Since the cage connecting portion is arranged between the balls (between the ball nests), the solid lubricant can be prevented from being drawn into the rolling surfaces. [Example]

Evaluation tests were carried out with various changes in the package volume of the solid lubricants of the following components A to C for the bearing alone and the backing roller unit for a tension leveler using the bearing.

Ingredient A: The grease as a lubricating ingredient uses mineral oil as the base oil and lithium soap as the thickener; ultra-high molecular weight polyethylene powder as the resin ingredient; then, this grease is mixed with this resin The ingredients are mixed in the prescribed proportions. The obtained mixture is filled between the balls in the ball bearing (the ball bearing in Fig. 2 ) by wrapping (winding) around the connecting portion of the cage, and then at a predetermined temperature. Heating and sintering, and then cooling to solidify, can be made into a ball bearing with a solid lubricant of component A encapsulated inside. According to the percentage value of the total volume of the solid lubricant in the volume of the inner space of the bearing shown in Table 1, the enclosed amount of the solid lubricant is adjusted. The place where the sealing is performed is the connection portion of the cage between the ball of the ball bearing and the ball as described above, and the sealing amount of each connection portion is adjusted to be substantially equal. The size (volume) of the solid lubricant on each connecting portion varies depending on the amount of encapsulation.

Ingredient B: Grease as a lubricating ingredient uses PAO oil as a base oil and a urea compound as a thickener; ultra-high molecular weight polyethylene powder as a resin ingredient; then, this grease is mixed with this resin The ingredients are mixed in a predetermined ratio (the same ratio as ingredient A). The obtained mixture is filled between the balls in the ball bearing (the ball bearing in Fig. 2 ) by wrapping (winding) around the connecting portion of the cage, and then at a predetermined temperature. Heating and sintering, and then cooling to solidify, can be made into a ball bearing with a solid lubricant of component B encapsulated inside. The method for adjusting the encapsulation amount of the solid lubricant is the same as in the case of the component A.

Ingredient C: Mix together modified silicone oil and epoxy hardener and grease. The grease system is the same as that of component B. The mixing ratio of the resin component (modified silicone oil and epoxy-based hardener) and the lubricating component (grease) is the same as that of component A. The obtained mixture is filled and packaged between the balls in the ball bearing (the ball bearing in Fig. 2) at the connection part of the retainer, and then heated and sintered at a predetermined temperature to be hardened. , can be made into a ball bearing with a solid lubricant containing component C inside. The method for adjusting the encapsulation amount of the solid lubricant is the same as in the case of the component A.

First, for each single ball bearing, a torque test at start-up and a torque test at rotation were carried out. The results are shown in Table 1. In each torque test, the test bearing was fixed, and under predetermined temperature and load conditions, the torque generated at startup and the torque when rotated at a constant speed were measured. Regardless of the amount of solid lubricant enclosed in each ball bearing unit, the test conditions for each ball bearing unit are the same. Regarding the "judgment of magnitude" of the torque at start-up, if the torque value exceeds the specified value, it is marked with "x" in Table 1, and if the torque value does not exceed the specified value, it is marked with "0". Regarding the "tactile judgment", it is the evaluation of the tactile sensation when the tester manually rotates the ball bearing. It is marked with "X", and if the tester does not feel the feeling of being stuck, it is marked with "〇". In addition, the "magnitude judgment" of the torque at the time of rotation is the same as the case of the torque at the time of starting. Regarding the "judgment of fluctuation", if the fluctuation range of the torque value in the predetermined time interval exceeds the predetermined value, it is marked as "X" in Table 1, and if the fluctuation range of the torque value in the predetermined time interval does not exceed the predetermined value , it is marked as "〇".

Moreover, about each ball bearing alone, the bearing after a predetermined time has elapsed (after the end of the test) was visually observed to determine the state after the operation, and the state of the solid lubricant was confirmed. The results are shown in Table 1. If there is any abnormality (record the content of the abnormality in Table 1), it is marked with "X" in Table 1, and if there is no special problem, it is marked with "○".

In addition, the ball bearing with the solid lubricant encapsulated with component A was assembled into the back roller unit for tension leveler (the back roller unit in Fig. 1 to Fig. 3 ), the torque at the time of starting was measured, and the appearance was measured. status determination. The test of the torque at start-up is the same as the case of the single bearing. The judgment of the appearance state is to visually observe the bearing in the back roller unit after a predetermined time has passed (after the test is completed), and confirm whether there is any See oil content. The results are shown in Table 2.

As shown in Tables 1 and 2, in the structure in which the solid lubricant is encapsulated in the ball bearing used to support the backing roller, by setting the total volume of the solid lubricant within a specific range (the volume of the inner space of the bearing 30% to 40%), it can be confirmed that it has the effect of suppressing the increase of the rotational torque.

For other effects, the "30%" back roller unit in Table 2 is set to 80% relative to the total volume of the solid lubricant of component A, and the other conditions are the same as the back roller unit, rotating Only 1/5 of the torque is required. [Industrial Availability]

The back roller unit of the present invention can be used in a tension leveler device. In particular, in the structure in which the solid lubricant is encapsulated in the ball bearing used to support the backing roller, the increase in the rotational torque can be suppressed, and it is very suitable for use in: There are no rollers inside where the radial load is small and low torque is required. Bearings (Needle Roller Bearings) are back roller units that only use ball bearings to support radial load and axial load.

1: Back roller unit 2: Ball bearing 3: Axis 4: Roller 5: inner wheel 6: Outer wheel 7: Retainer 7a: Bead Nest 7b: Links 8: Ball 9: solid lubricant 10: Sealing plate 11: cover plate 21: Tension leveler device 22: sheet metal 23: Roller unit 24: Work roll 25: Intermediate Roller 26: Back roller 27: Deflection roller

1 is a perspective view showing an example of the back idler unit of the present invention. [ FIG. 2 ] is an enlarged view showing the ball bearing portion in FIG. 1 . [Fig. 3] is a front view showing the ball bearing portion in Fig. 2. [Fig. Fig. 4 is a schematic diagram showing the tension leveler device.

1: Back roller unit

2: Ball bearing

3: Axis

4: Roller

5: inner wheel

6: Outer wheel

7: Retainer

7a: Bead Nest

7b: Links

8: Ball

9: solid lubricant

10: Sealing plate

11: cover plate

Claims (6)

A back roller unit for a tension leveler, which is fastened between a roller and a shaft, and is provided with a ball bearing that rotatably supports the roller on the shaft, and is characterized by: : The aforementioned ball bearing is provided with an inner wheel and an outer wheel as a track wheel, a plurality of balls interposed between the inner wheel and the outer wheel, and a retainer for holding these balls, In the bearing inner space of the ball bearing, a solid lubricant is encapsulated, and the total volume of the solid lubricant accounts for 30% to 40% of the volume of the bearing inner space. The back roller unit for a tension leveler according to claim 1, wherein, The retainer is a wave-shaped retainer that connects a pair of annular bodies together by connecting portions between the ball nests for holding the balls, The solid lubricant is connected between the balls and is fixed to the connection portion of the cage. The back roller unit for a tension leveler according to claim 1, wherein, The aforementioned solid lubricant is a solidified product of a mixture of a resin component and a lubricating component. The back roller unit for a tension leveler according to claim 3, wherein, The aforementioned resin component is an ultra-high molecular weight polyolefin, and the aforementioned lubricating component is a grease containing a base oil and a thickener. The back roller unit for a tension leveler according to claim 1, wherein, The ball bearing has a seal plate fixed to one of the inner ring and the outer ring, and has a gap between the seal plate and the other track wheel. The back roller unit for a tension leveler according to claim 1, wherein, There are no roller bearings inside the back idler unit.

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