JP2009264403A - Sealed rolling bearing unit and seal ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a structure capable of preventing the occurrence of a pressure difference between a rolling element arranging space 16 and an external space, even if the bearing temperature changes, in the structure for fluid-tightly blocking up mutual end surfaces in the axial direction of both inner ring elements 11 and 11 by a seal ring 7 installed in a recessed groove 18, by forming the recessed groove 18 on an inner peripheral surface of a butting part of the mutual end surfaces in the axial direction of a pair of inner ring elements 11 and 11. <P>SOLUTION: This seal ring 7 is constituted by combining an annular ring-shaped sealant and an annular ring-shaped or segmental annular ring-shaped core material for reinforcing this sealant. Among these, the sealant is made of a water repellent-oil repellent, ventilating and flexible raw material, and the core material is made of an elastic material. The sealant is pressed to a bottom surface of this recessed groove 18 based on elastic force of the core material in a state of installing the seal ring 7 in the recessed groove 18. The problem is solved by adopting such a constitution. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to, for example, a sealed rolling bearing unit used for rotatably supporting roll necks provided at both ends of a roll constituting a rolling mill with respect to a support device, and a rolling element of the sealed rolling bearing unit. The present invention relates to an improvement with a seal ring used for sealing an installation space.

  A roll constituting a rolling mill for rolling a metal material is sealed as shown in FIG. 8, for example, with respect to a support device that fixes a cylindrical portion called a roll neck provided at the center of both axial end faces. It is rotatably supported by type multi-row tapered roller bearings. The sealed multi-row tapered roller bearing shown in FIG. 8 is described in Patent Document 1, and includes an outer ring 1, an inner ring 2, a plurality of tapered rollers 3, 3, and a pair of annular seals. Holders 4, 4, a pair of sliding contact type seal rings 5, 5, a pair of O-rings 6, 6, and one seal ring 7 are provided.

  Of these, the outer ring 1 includes one outer ring element 8a disposed in the central portion in the axial direction and two outer ring elements 8b and 8b disposed at both ends in the axial direction, which are adjacent to each other in the axial direction. , 8b, and two outer ring spacers 9, 9 each having a short cylindrical shape. Two rows of outer ring raceways 10 and 10 each having a conical concave shape are formed on the inner peripheral surface of one outer ring element 8a arranged in the central portion in the axial direction. Further, the outer ring raceway 10 having a partially conical concave shape is formed in each row on the inner peripheral surface of the two outer ring elements 8b, 8b arranged at both ends in the axial direction. Therefore, four rows of outer ring raceways 10 and 10 are provided on the inner peripheral surface of the outer ring 1.

  The inner ring 2 is composed of a pair of inner ring elements 11, 11 that face each other in the axial direction. Two inner ring raceways 12 and 12 having a partially conical convex shape are formed on the outer peripheral surfaces of both inner ring elements 11 and 11 respectively. Therefore, four rows of inner ring raceways 12 and 12 are provided on the outer peripheral surface of the inner ring 2. The tapered rollers 3 and 3 are held by the cages 13 and 13 between the four rows of outer ring raceways 10 and 10 and the four rows of inner ring raceways 12 and 12, respectively. It is provided so that it can roll freely.

  The pair of annular seal holders 4, 4 are disposed adjacent to both sides in the axial direction of the outer ring 1. The seal rings 5 and 5 are assembled between the inner peripheral surfaces of the seal holders 4 and 4 and the outer peripheral surfaces of both end portions of the inner ring 2 in the axial direction. Each of the seal rings 5 and 5 includes an annular cored bar 14 and an annular elastic member 15 that is coupled and fixed to the inner peripheral edge of the cored bar 14 over the entire circumference. Of these, the metal core 14 is fitted and fixed to the seal holders 4 and 4, and the leading edge of the elastic material 15 is brought into sliding contact with the outer peripheral surfaces of both end portions in the axial direction of the inner ring 2. Thereby, both axial direction opening of the rolling element installation space 16 which exists between the inner peripheral surface of the said outer ring | wheel 1 and the outer peripheral surface of the said inner ring | wheel 2 is sealed. Further, locking grooves 17 and 17 are formed on the outer peripheral surfaces of the seal holders 4 and 4 over the entire circumference, and the O-rings 6 and 6 are engaged in the locking grooves 17 and 17. It has stopped. In a free state, the outer diameter dimensions of the O-rings 6 and 6 are larger than the outer diameter dimensions of the seal holders 4 and 4.

  In addition, a concave groove 18 is formed on the inner peripheral surface of the abutting portion between the axial end surfaces of the inner ring elements 11, 11 so as to extend between the inner ring elements 11, 11. is doing. The seal ring 7 is assembled in the groove 18. As shown in detail in FIG. 9, the seal ring 7 is composed of a seal material 19 formed in a ring shape by rubber and a metal and ring-shaped core material 22 for reinforcing the seal material 19. Become. Of these, the sealing member 19 has a base portion 23 that is substantially rectangular in cross section and formed in an annular shape as a whole, and a radial thickness formed in a state extending in the axial direction from the entire circumference of the base portion 23. And a small annular seal lip 24. Such a seal ring 7 is assembled in the groove 18 as shown in the figure, and the base 23 constituting the seal material 19 is placed on one of the bottom surface and both axial side walls of the groove 18 (see FIG. 9) is elastically brought into contact with the entire circumference of the portion corresponding to the inner ring element 11. At the same time, the tip edge of the seal lip 24 constituting the seal material 19 is placed on the entire circumference of the portion corresponding to the other inner ring element 11 (on the right side in FIG. 9) of the axially opposite side walls of the groove 18. It is in elastic contact. Thereby, the space between the axial end surfaces of the inner ring elements 11 and 11 is sealed.

  A cylindrical roll neck (not shown) provided at the center of the axial end surface of the roll constituting the rolling mill by the sealed multi-row tapered roller bearing unit configured as described above is a housing constituting the support device. When the inner ring side (not shown) is rotatably supported, the outer ring 1 and the pair of seal holders 4 and 4 are fitted and supported on the housing, and the inner ring 2 is fitted on the roll neck. To support. Accordingly, the O-rings 6, 6 are provided between the bottom surfaces of the locking grooves 17, 17 formed on the outer peripheral surfaces of the seal holders 4, 4 and the cylindrical inner peripheral surface of the housing. Is elastically compressed. Thereby, the space between the outer peripheral surface of each of the seal holders 4 and 4 and the inner peripheral surface of the housing is sealed.

  The sealed multi-row tapered roller bearing unit as described above is used in an environment where foreign matters such as cooling water and dust are present outside. Further, in the case of the sealed multi-row tapered roller bearing unit as described above, the fit between the outer peripheral surface of the roll neck and the inner peripheral surface of the inner ring 2 is a clearance fit ( Loose fit). For this reason, slip occurs between the two peripheral surfaces, and wear powder is generated. Therefore, a plurality of communication paths existing between the external space in which foreign matter such as cooling water, dust and the like, wear powder exists, and the rolling element installation space 16 are respectively connected to the pair of seal rings 5 and 5. The rolling element installation space 16 is sealed by closing with the pair of O-rings 6 and 6 and the single seal ring 7. Further, by adopting such a configuration, the cooling water or the like is prevented from entering the rolling element installation space 16 from the external space, and the lubricating grease sealed in the rolling element installation space 16 Is prevented from leaking into the external space.

  By the way, in the case of the above-described sealed multi-row tapered roller bearing unit for the roll neck, when the air in the rolling element installation space 16 expands due to a high temperature during operation, the air in the rolling element installation space 16 A sliding contact portion (intersection) between the tip edges of the elastic members 15 and 15 constituting the pair of seal rings 5 and 5 and the outer peripheral surfaces of both end portions in the axial direction of the inner ring 2 and the seal ring 7 are constituted. Through the contact portion (intermediate portion) between the tip edge of the seal lip 24 and the inner surface of the concave portion 18, it gradually leaks into the external space. In the case of the first example of the above-described conventional structure, the seals that are in contact with the tip edges of the elastic members 15 and 15 that are in sliding contact with the outer peripheral surfaces of both ends in the axial direction of the inner ring 2 and the inner surfaces of the recesses 18. The tip edge of the lip 24 is inclined toward the outer space side. That is, when the air in the rolling element installation space 16 tends to leak into the external space through each sliding contact portion and the contact portion, there is a gap in each sliding contact portion and part of the contact portion. It tends to occur. For this reason, the leakage of the air is easily performed.

  On the other hand, when the air in the rolling element installation space 16 contracts after the operation is stopped and the temperature is lowered, the air in the external space is passed through the sliding contact part and the contact part. It tends to be sucked in. However, in the case of the first example of the conventional structure described above, the seals that contact the tip edges of the elastic members 15 and 15 that are in sliding contact with the outer peripheral surfaces of both axial ends of the inner ring 2 and the inner surfaces of the recesses 18. The tip edge of the lip 24 is inclined toward the outer space side. That is, when the air existing in the external space tends to be sucked into the rolling element installation space 16 through each sliding contact portion or the contact portion, the sliding contact portion and a part of the contact portion are provided. The gap is less likely to occur. Therefore, the air is hardly sucked, and the rolling element installation space 16 is in a negative pressure state. As a result of the negative pressure state of the rolling element installation space 16 as described above, the cooling water is sucked into the rolling element installation space 16 from the external space through each sliding contact part and the contact part. There was a possibility that a problem that occurred. Further, when the rolling element installation space 16 is in a negative pressure state, the leading edges of the elastic members 15 and 15 constituting the both seal rings 5 and 5 are caused by the atmospheric pressure of the outer space so that both ends of the inner ring 2 in the axial direction. Strongly pressed against the outer peripheral surface. As a result, the wear of the leading edges of both elastic members 15 and 15 is promoted, and the rate of decrease in the sealing function of both elastic members 15 and 15 is increased. Therefore, the cooling water is more easily drawn into the rolling element installation space 16 through the sliding contact portions.

  When the cooling water is drawn into the rolling element installation space 16, the lubrication performance of the grease existing in the rolling element installation space 16 is impaired, and the bearing life is reduced. Therefore, in order to avoid such a situation, it is necessary to effectively prevent the cooling water from being drawn into the rolling element installation space 16 through the sliding contact portions. Therefore, specifically, it is necessary to realize a structure capable of preventing the rolling element installation space 16 from becoming a negative pressure state.

  In view of such circumstances, Patent Document 2 describes a structure in which a seal ring 7a as shown in FIG. 10 is used instead of the seal ring 7 shown in FIG. The seal ring 7a constituting the second example of the conventional structure shown in FIG. 10 includes a seal material 19a formed entirely of rubber in an annular shape, and the entire circumference in the center in the width direction of the inner peripheral surface of the seal material 19a. And an annular spring 21 serving as a core material, which is locked in a locking groove 20 formed over the surface. A part of the sealing material 19a (shown in a free state for the sake of convenience in FIG. 10) is brought into contact with the entire circumference of both sides and both side walls of the bottom surface of the groove 18 in the width direction. . At the same time, the elastic force of the annular spring 21 urges the sealing material 19a toward the bottom surface of the concave groove 18 outward in the radial direction. And by employ | adopting such a structure, between the axial direction end surfaces of a pair of inner ring elements 11 and 11 is sealed with the said seal ring 7a. At the same time, by appropriately adjusting the tightening margin of the sealing material 19a with respect to the inner surface of the concave groove 18 and the elasticity of the annular spring 21, the inner surface of the concave groove 18 and the above-mentioned at high temperature and low temperature respectively. Through the contact portion with the sealing material 19a, only air can enter and exit between the rolling element installation space 16 (see FIG. 8) and the external space, and other foreign matters can be prevented from entering and exiting.

  According to the second example of such a conventional structure, it is possible to effectively prevent the rolling element installation space 16 from being in a negative pressure state, so that the problem described in the first example of the conventional structure described above occurs. Things can be effectively prevented. However, in the case of the second example of the conventional structure as described above, it is difficult to properly adjust the tightening margin of the sealing material 19a against the inner surface of the concave groove 18 and the elasticity of the annular spring 21. In addition, there is a problem that the manufacturing cost increases because highly accurate dimensional management or the like is necessary to realize this appropriate adjustment. In addition, if the tightening allowance and the elasticity are too small due to this adjustment, foreign matter or the like easily enters the rolling element installation space 16 from the external space through the contact portion, or a part of the seal ring 7a is formed. When the roll neck hangs inward in the radial direction and protrudes out of the groove 18 and is inserted and removed from the inner diameter side of the inner ring 2 during maintenance, the protruding portion interferes with the roll neck and breaks. To do. On the other hand, if the tightening allowance and elasticity are too large, the air permeability at low temperatures is lost and the same problem as in the first example of the conventional structure described above occurs.

  Further, Patent Document 1 describes a structure as shown in FIG. 11 as an improved product of the first example of the conventional structure described above. In the case of the third example of the conventional structure shown in FIG. 11, circular thin-walled portions are respectively provided at a plurality of locations in the circumferential direction of the axially intermediate portion of the seal lip 24 constituting the seal material 19 'of the seal ring 7'. 25, and each thin portion 25 is formed with a cut 26 extending in the diametrical direction, which divides each thin portion 25 into a pair of semicircular portions. In the free state, each of the cut portions 26 is in a closed state. In the case of the third example of the conventional structure configured as described above, when a predetermined pressure difference is generated between the rolling element installation space 16 (see FIG. 8) and the external space as the temperature changes, Various pressure differential adjustment functions work. That is, when the pressure difference between the two spaces reaches a predetermined value, each of the cut portions 26 is elastically spread by the pressure difference. Then, air enters and exits between the two spaces through each of the cuts 26, whereby the pressure difference is suppressed to the predetermined value or less. For this reason, it can prevent effectively that the said rolling-element installation space 16 becomes an excessive negative pressure state. Therefore, it is possible to effectively prevent the occurrence of the problems described in the first example of the conventional structure described above.

  However, in the case of the third example having such a conventional structure, the processing of the seal lip 24 is cumbersome and costly. In addition, in order to appropriately open and close the cut portion 26 and to exert the above-described pressure difference adjustment function appropriately, the tightening margin of the seal lip 24 with respect to the inner surface of the groove 18 is appropriately managed. It is necessary to make the stress of the cut portion 26 appropriate. For this purpose, it is necessary to sufficiently secure the dimensional accuracy and shape accuracy of the sealing material 19 ′ including the concave groove 18 and the sealing lip 24. Accordingly, the machining cost of the pair of inner ring elements 11 and 11 forming the concave groove 18 and the cost of the mold for producing the sealing material 19 ′ are increased accordingly.

JP 2000-104747 A Japanese Patent Laid-Open No. 9-329243

  The sealed-type rolling bearing unit and seal ring of the present invention are capable of maintaining liquid-tightness between the axial end faces of a pair of inner ring elements in a situation where temperature changes occur in view of the above-described circumstances, and rolling elements Realizes a structure that can eliminate the pressure difference between the installation space and the external space, and can reduce the processing cost of each inner ring element that forms the groove and the manufacturing cost of the seal ring to be assembled in the groove. Invented as much as possible.

  A sealed-type rolling bearing unit that is an object of the present invention includes an outer ring having a double-row or multi-row outer ring raceway on an inner peripheral surface, an inner ring having a double-row or multi-row inner ring raceway on an outer peripheral surface, and each outer ring raceway. Between each of the inner ring raceways and the inner ring raceways, and a plurality of rolling elements provided in a freely rotatable manner for each row, and a rolling element installed between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. And a pair of sliding contact type seal rings that closes both axial openings of the space. Each of the inner rings includes a pair of inner ring elements each having one or more rows of the inner ring raceways on the outer peripheral surface thereof and abutting each other in the axial direction. In addition, a concave groove is formed on the inner peripheral surface of the abutting portion between the axial end surfaces of both inner ring elements over the entire circumference in a state of being spanned over both the inner ring elements. Further, a seal ring for liquid-tightly closing between the axial end surfaces of the inner ring elements is assembled in the concave groove.

  In particular, in the sealed rolling bearing unit according to claim 1, the seal ring is formed of a material having water and oil repellency, air permeability, and flexibility such as elasticity as a whole in an annular shape. By combining the core material for reinforcing the sealing material, which is formed in an annular shape or a partially annular shape with an elastic material, the whole is configured in an annular shape. And it can attach or detach with respect to the said ditch | groove after completion, deforming the said sealing material temporarily with elastically deforming the said core material. In addition, with the seal ring assembled in the groove, the seal material is pressed against the entire circumference of the bottom surface of the groove corresponding to the inner ring elements based on the elasticity of the core material. It is done. At the same time, in the same state, the entire seal ring is accommodated in the concave groove.

  According to a second aspect of the present invention, there is provided the seal ring according to claim 2, wherein the seal material is formed in a ring shape by a material having water and oil repellency, breathability and flexibility, and an annular shape or a non-circular shape by an elastic material. The whole is configured in an annular shape by combining with the core material for reinforcing this sealing material. And it can be attached or detached with respect to the said ditch | groove after completion, deform | transforming the said sealing material temporarily along with elastically deforming this core material. Further, in a state where it is assembled in the concave groove, the sealing material is pressed against the entire circumference of the portion corresponding to the inner ring elements on the bottom surface of the concave groove based on the elasticity of the core material. At the same time, in the same state, the whole fits in the concave groove.

  Examples of materials having water / oil repellency, air permeability, and flexibility such as elasticity for constituting the sealing material include, for example, a heat resistant fiber material impregnated with a water / oil repellent and cork chips. A cork molded product having air permeability such as carbonized cork, which is solidified and molded, can be used.

  In carrying out the present invention as described above, it is preferable to use a material having air permeability (for example, a material made of a mesh-like metal material having elasticity) as the core material constituting the seal ring. To do. In addition, when using a core made of a mesh-like metal material having elasticity as the core material, preferably, the core material has a U shape whose cross-sectional shape opens to the outer diameter side, It is assumed that is configured in a non-circular shape.

  As described above, in the case of the sealed rolling bearing unit and the seal ring of the present invention, the material constituting the seal material of the seal ring has water and oil repellency and flexibility such as elasticity, and The sealing material is pressed on the entire circumference of the portion corresponding to the pair of inner ring elements on the bottom surface of the concave groove based on the elasticity of the core material (in close contact with the tightening margin). For this reason, foreign substances such as water such as cooling water and wear powder sludge existing in the external space are drawn into the rolling element installation space through the portion between the sealing material and the bottom surface of the concave groove and the inside of the sealing material. Or oil such as lubricating grease existing in the rolling element installation space can be prevented from leaking to the external space.

  In particular, in the case of the present invention, since the material constituting the sealing material has air permeability, air is not blocked by the sealing material. Therefore, when the rolling element installation space tends to become positive or negative pressure due to temperature change, air enters and exits between the rolling element installation space and the external space through the inside of the sealing material. it can. Therefore, it is possible to prevent a pressure difference from occurring between these two spaces. As a result, the rolling element installation space is in an excessively negative pressure state, or the negative pressure state of the rolling element installation space continues for a long time. It is possible to prevent the wear of the edge) slidably contacting the surface from being accelerated. For this reason, when the cooling water etc. which exist in external space become easy to be drawn in in the said rolling element installation space through the sliding contact part (interposition part) of the front-end edge of the elastic material which comprises the said both seal rings, and the other party surface. It is possible to prevent the above-mentioned trouble from occurring.

  In the present invention, since the seal ring can be attached to and detached from the completed groove, the seal ring in the groove can be replaced without disassembling the bearing unit during maintenance. Moreover, in the case of this invention, the raw material which comprises the said sealing material has a softness | flexibility. For this reason, even if there are some dimensional errors and shape errors in the groove, the seal material flexibly deforms to absorb these errors, and the contact state between the seal material and the inner surface of the groove is It can be done properly. Therefore, it is not necessary to strictly manage the dimensional accuracy and shape accuracy of the groove. Further, since the sealing material can be produced by cutting out a large fiber material, it is not necessary to use an expensive mold when producing the sealing material. Therefore, the processing cost of the pair of inner ring elements forming the concave grooves and the manufacturing cost of the seal ring can be sufficiently suppressed.

  In the case of carrying out the present invention, if a material having air permeability (for example, one made of an elastic mesh metal material) is used as the core material constituting the seal ring, the entire seal ring is used. The air permeability of can be improved. In addition, when using a core made of an elastic mesh-like metal material as the core material, the core material has a U shape whose cross-sectional shape opens to the outer diameter side, and the whole is a missing circle. If it is configured in an annular shape, the spring rigidity of the core can be sufficiently increased. That is, the elastic force toward the outer diameter side of the core material for pressing the sealing material against the bottom surface of the concave groove and holding the entire seal ring in the concave groove can be sufficiently increased.

[First example of embodiment]
1 and 2 show a first example of an embodiment of the present invention. The feature of this example is the seal ring 7b assembled in the groove 18 formed in the inner peripheral surface of the abutting portion between the axial end surfaces of the pair of inner ring elements 11a, 11a. The structure and operation of other parts are almost the same as in the case of the first example of the conventional structure shown in FIG. For this reason, overlapping illustrations and explanations are omitted or simplified, and the following description will focus on features of this example and parts different from the first example of the conventional structure.

  In the case of this example, the seal ring 7b is made of a heat-resistant fiber material impregnated with a water- and oil-repellent agent. It consists of a core material 22b made of spring steel and joined in a state of being embedded in the central portion in the width direction of the surface layer portion of the inner peripheral surface of 19b. Such a seal ring 7b is assembled in the concave groove 18 as follows. First, the groove 18 is completed by assembling the bearing unit. Then, in this state, as shown in FIG. 2, the core material 22b is elastically deformed in the directions of arrows a and i (circumferential direction) (accordingly, the seal material 19b is temporarily deformed). The seal ring 7b is inserted into the inner diameter side of the inner ring 2 while elastically reducing the diameter of the seal ring 7b. Then, in a state where the seal ring 7b is moved to the inner diameter side of the concave groove 18, the diameter dimension of the seal ring 7b is elastically restored. As a result, as shown in FIG. 1, the seal ring 7 b is assembled in the concave groove 18.

In the case of this example, with the seal ring 7b assembled in the concave groove 18, the entire circumference of the portion corresponding to the inner peripheral surface of the end portion of the pair of inner ring elements 11a, 11a in the bottom surface of the concave groove 18 is obtained. In addition, the outer peripheral surface of the sealing material 19b is pressed on the basis of the elasticity of the core material 22b (closely tightened). Further, the entire seal ring 7 b is set in the concave groove 18. That is, in the state shown in FIG. 1, the inner diameter d _22b of the core material 22b (and the sealing material 19b) is slightly larger than the inner diameter d _11a of the inner ring elements 11a and 11a (d _22b > d _11a ) to be Further, by making the width dimension W _19b of the sealing material 19b slightly smaller than the width dimension W _{18 of the} concave groove 18 (W _19b <W ₁₈ ), the seal ring 7b is placed in the concave groove 18 as described above. It is easy to perform the work of assembling. Since the width dimension W _22b of the core material 22b is smaller than the width dimension W _19b of the seal material 19b (W _22b <W _19b ), the opening of the groove 18 is formed by the core material 22b. It is never completely blocked.

  Further, in the case of this example, the rolling element installation space 16 (see FIG. 8) is provided at one or a plurality of locations in the circumferential direction between the axial end surfaces of the inner ring elements 11a and 11a, which are in contact with each other. A vent hole 27 communicating with the concave groove 18 is formed in the radial direction. However, when the present invention is carried out, such a vent hole 27 is not necessarily provided. In the case of this example, the operation of removing the seal ring 7b from the concave groove 18 during maintenance can be performed based on elastically reducing the diameter of the seal ring 7b, or disassembling the bearing unit. You can do it based on things.

  As described above, in the case of the sealed type rolling bearing unit of the present example, the seal ring 7b is assembled in the concave groove 18 to correspond to the pair of inner ring elements 11a and 11a in the bottom surface of the concave groove 18. A sealing material 19b made of a heat-resistant fiber material impregnated with a water / oil repellent agent is pressed against each of the portions based on the elasticity of the core material 22b. Therefore, foreign matter such as water such as cooling water and wear powder sludge existing in the external space passes through the space between the sealing material 19b and the bottom surface of the concave groove 18 and the inside of the sealing material 19b. 16 (see FIG. 8), or oil such as lubricating grease existing in the rolling element installation space 16 can be prevented from leaking to the external space.

  In particular, in the case of this example, the heat-resistant fiber material impregnated with the water and oil repellent that constitutes the sealing material 19b has air permeability, so that the air is not blocked by the sealing material 19b. For this reason, when the rolling element installation space 16 tends to become positive pressure or negative pressure due to the change in the bearing temperature that occurs during operation, the rolling element installation space 16 and the outside through the inside of the sealing material 19b. Air can enter and leave the space. In particular, in the case of this example, a vent hole 27 is provided between the axial end surfaces of the inner ring elements 11a and 11a that are in contact with each other, and communicates the rolling element installation space 16 and the concave groove 18. For this reason, air can smoothly enter and exit between the rolling element installation space 16 and the external space. Therefore, it is possible to prevent a pressure difference from occurring between these two spaces. As a result, the rolling element installation space 16 becomes in an excessively negative pressure state, or the negative pressure state of the rolling element installation space 16 continues for a long time, and the elastic material constituting the pair of seal rings 5 and 5. 15 and 15 (see FIG. 8) can be prevented from being accelerated at the leading edge. For this reason, the cooling water or the like existing in the outer space is caused by the leading edges of the elastic members 15 and 15 constituting the seal rings 5 and 5 and the outer peripheral surfaces of the axial ends of the inner ring 2 (see FIG. 8 for the entire structure) It is possible to prevent the occurrence of a problem that it is easy to be drawn into the rolling element installation space 16 through the sliding contact portion (interspace portion).

  In the case of this example, since the seal ring 7b can be attached to and detached from the completed concave groove 18, the seal ring 7b in the concave groove 18 can be replaced without disassembling the bearing unit during maintenance. . In the case of this example, the heat-resistant fiber material impregnated with the water / oil repellent that constitutes the sealing material 19b has flexibility. For this reason, even if there are some dimensional errors and shape errors in the concave groove 18, the sealing material 19 b flexibly deforms to absorb these errors, and the outer peripheral surface of the sealing material 19 b and the concave groove The contact state with the bottom surface of 18 can be made appropriate. Therefore, it is not necessary to strictly manage the dimensional accuracy and shape accuracy of the groove 18. Further, since the sealing material 19b can be manufactured by cutting out a large fiber material, it is not necessary to use an expensive mold when manufacturing the sealing material 19b. Therefore, the processing cost of the pair of inner ring elements 11a and 11a forming the concave groove 18 and the manufacturing cost of the seal ring 7b can be sufficiently suppressed.

  In the case of this example, the core material 22b constituting the seal ring 7b is formed in a generally cylindrical shape with spring steel, and its spring rigidity is the second of the conventional structure shown in FIG. The spring rigidity of the annular spring 21 in the example is sufficiently large. For this reason, the outer peripheral surface of the sealing material 19b can be pressed sufficiently strongly against the bottom surface of the concave groove 18 by the elasticity of the core material 22b. At the same time, there is a problem that a part of the seal ring 7b assembled in the concave groove 18 hangs down radially inward and protrudes radially inward from the inner peripheral surfaces of the inner ring elements 11a and 11a. Occurrence can be reliably prevented based on the spring rigidity of the core member 22b. Accordingly, it is possible to reliably prevent a problem that the roll neck interferes with the seal ring 7b when the roll neck is inserted into and removed from the inner diameter side of the inner ring elements 11a and 11a during maintenance.

[Second Example of Embodiment]
3 to 6 show a second example of the embodiment of the present invention. Also in the case of this example, as in the case of the first example described above, the core material 22c constituting the seal ring 7c is formed in a partially annular shape as a whole. However, in the case of this example, the core material 22c is made of a mesh-like metal material having good spring properties, and the cross-sectional shape of the core material 22c is a U-shape with an outer diameter side opened. And it mounts | wears in the state which fits the radial direction inner half part of the sealing material 19b inside this core material 22c opened to radial direction outward. In the case of this example, the width dimension W _22c of the core material 22c is slightly smaller than the width dimension W ₁₈ of the concave groove 18 like the width dimension W _19b of the radially outer half of the sealing material 19b { The size is about W _22c (= W _19b ) <W ₁₈ }.

  In the case of this example configured as described above, since the material of the core material 22c constituting the seal ring 7c is a net-like metal material, the air permeability of the core material 22c can be improved, and the seal The air permeability of the entire ring 7c can be improved. Moreover, although the core material 22c is a net-like metal material, the cross-sectional shape thereof is a U-shape with an outer diameter side opened. For this reason, as in the case of the first example described above, the spring rigidity of the core member 22c can be sufficiently increased. Further, since the material of the core material 22c is a net-like metal material, the processing for manufacturing the core material 22c can be easily performed. Furthermore, in the case of this example, since the inner half of the seal member 19b can be fitted inside the core member 22c that opens to the outer diameter side, the assembly operation of the seal ring 7c can be performed. Can be easily performed. Other configurations and operations are the same as those of the first example described above.

[Third example of embodiment]
FIG. 7 shows a third example of the embodiment of the present invention. In the case of this example, the seal ring 7d has a pair of core members 22d and 22d formed entirely in a ring shape by spring steel wires at the portions near both axial ends of the surface layer portion of the inner peripheral surface of the seal material 19b. They are combined in a state where they are embedded concentrically. By adopting such a configuration, the seal ring 7d is elastically contracted by elastically deforming both the core materials 22d and 22d (and thereby temporarily deforming the seal material 19b). The diameter can be increased (the diameter of the circumscribed circle of the seal ring 7d can be reduced elastically). Other configurations and operations are the same as in the case of the first example described above (including the point that the spring rigidity of both the core members 22d and 22d can be sufficiently increased).

  As described above, the spring stiffness of the core members 22b to 22d in each example of the embodiment described above is larger than that of the annular spring 21 of the second example of the conventional structure shown in FIG. Can be big enough. For this reason, in the structure using rubber as the seal material constituting the seal ring (for example, the second example of the conventional structure), the core materials 22b to 22d are used as the core material constituting the seal ring (the annular spring). If used, the pressing force of the sealing material against the bottom surface of the concave groove and the force for holding the entire seal ring in the concave groove are respectively (when the annular spring 21 is used). Can be large enough).

  However, as described above, when rubber is used as the seal material constituting the seal ring, the pressure in the rolling element installation space becomes a positive pressure in an operation state in which the bearing temperature becomes high (that is, at a high temperature). When the positive pressure value in the rolling element installation space exceeds the sealing force of the pair of sliding contact type seal rings, the rolling element installation space passes through the sliding contact portions of both sliding contact type seal rings. Air leaks into the external space. For this reason, the positive pressure value in the rolling element installation space at a high temperature becomes a value commensurate with the sealing force of the double sliding contact type seal ring. However, when the sealing force of the seal ring is smaller than the sealing force of the both sliding contact type seal rings, the positive pressure value in the rolling element installation space is increased. Before reaching a value that matches the stopping force, the air in the rolling element installation space leaks into the external space through the contact portion of the seal ring. Therefore, the positive pressure value in the rolling element installation space at a high temperature is reduced by that amount.

  On the other hand, when the temperature is high, more cooling water is present in the external space. For this reason, it is particularly important that the cooling water intrusion preventing function is sufficiently exerted at high temperatures. However, this cooling water intrusion prevention function is more effective as the positive pressure value in the rolling element installation space increases. For this reason, as described above, when the positive pressure value in the rolling element installation space at a high temperature becomes small, there arises a problem that the cooling water intrusion prevention function is reduced accordingly. Further, as described above, when the positive pressure value in the rolling element installation space at a high temperature becomes small (the amount of air discharged from the rolling element installation space to the external space at a high temperature increases), the bearing temperature subsequently decreases. Thus, when the pressure in the rolling element installation space becomes negative, the amount of air drawn from the external space into the rolling element installation space through the both sliding contact portions increases. For this reason, the problem that the said cooling water with this air becomes easy to be drawn in into rolling-element installation space generate | occur | produces.

  On the other hand, if the core material 22b to 22d of each example of the embodiment described above is used as the core material constituting the seal ring, the pressing force of the seal material against the bottom surface of the concave groove can be sufficiently increased. It is possible to effectively prevent the sealing force of the seal ring from becoming smaller than the sealing force of the sliding contact type seal ring. For this reason, it can prevent effectively that the positive pressure value in the rolling element installation space at the time of high temperature becomes smaller than the value corresponding to the sealing force of the said both sliding contact type seal ring as mentioned above. Therefore, it is possible to effectively prevent the occurrence of the various problems as described above.

  Moreover, if a core material that is formed in an annular shape or a not-annular shape as a whole by aluminum or an aluminum alloy is used as the core material constituting the seal ring, the amount of diameter expansion based on the thermal expansion of the core material is the same. It can be sufficiently larger than the diameter expansion of the inner ring provided with the concave groove. For this reason, the pressing force of the sealing material against the bottom surface of the concave groove can be sufficiently increased at a high temperature. Therefore, it is possible to effectively prevent the sealing force of the seal ring from becoming smaller than the sealing force of the sliding contact type seal ring at a high temperature. For this reason, it is possible to effectively prevent the positive pressure value in the rolling element installation space from becoming smaller than a value commensurate with the sealing force of the both sliding contact type seal ring at a high temperature. Therefore, it is possible to effectively prevent the occurrence of the various problems as described above.

  In the case of carrying out the present invention, the sealing force of the seal ring is not limited if the seal material constituting the seal ring is brought into contact with not only the bottom surface of the groove but also the axial side walls of the groove. Can be made larger. Moreover, when implementing this invention, the annular spring shown in the above-mentioned FIG. 10 can also be used as a core material which comprises a seal ring.

The figure similar to FIG. 9 which shows the 1st example of embodiment of this invention. The figure which looked at the core material which comprises the seal ring of a 1st example from the axial direction. The figure similar to FIG. 1 which shows the 2nd example of embodiment of this invention. The perspective view of the core material which comprises the seal ring of a 2nd example. The A section enlarged view of FIG. The figure which looked at the core material which comprises the seal ring of a 2nd example from the axial direction. The figure similar to FIG. 1 which shows the 3rd example of embodiment of this invention. The half part sectional view showing the 1st example of the conventional structure of a sealed type multi-row tapered roller bearing. The B section enlarged view of FIG. The figure similar to FIG. 9 which shows the 2nd example of conventional structure. The figure similar to FIG. 9 which shows the 3rd example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Inner ring 3 Tapered roller 4 Seal holder 5 Seal ring 6 O ring 7, 7 ', 7a-7d Seal ring 8a, 8b Outer ring element 9 Outer ring spacer 10 Outer ring raceway 11, 11a Inner ring element 12 Inner ring raceway 13 Cage 14 Metal core 15 Elastic material 16 Rolling element installation space 17 Locking groove 18 Recessed groove 19, 19 ', 19a, 19b Sealing material 20 Locking groove 21 Annular spring 22, 22b-22d Core material 23 Base 24 Seal lip 25 Thin part 26 Cut 27 Vent

Claims (2)

  An outer ring having a double-row or multi-row outer ring raceway on the inner peripheral surface, an inner ring having a double-row or multi-row inner ring raceway on the outer peripheral surface, and between each outer ring raceway and each inner ring raceway, for each row A pair of rolling elements provided in a freely rotatable manner, and a pair of sliding contacts that block both axial openings of the rolling element installation space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. The inner ring includes a pair of inner ring elements each having one or more rows of the inner ring raceways on the outer peripheral surface thereof and abutting each other in the axial direction. Therefore, a concave groove is formed on the inner peripheral surface of the abutting portion between the axial end faces of both the inner ring elements, and is formed over the entire circumference in a state of spanning the two inner ring elements. A hermetic rolling bearing unit is assembled with a seal ring that tightly seals between the axial end faces of both inner ring elements. In this case, the seal ring is formed in a ring shape or a ring shape with an elastic material, and a seal material that is formed in a ring shape with a material having water and oil repellency, breathability, and flexibility. By combining with a core material to reinforce this seal material, the whole is configured in an annular shape, and after completion of the seal material, while temporarily deforming the seal material as the core material is elastically deformed In the state where the seal ring is assembled in the groove, the entire circumference of the portion corresponding to the inner ring elements on the bottom surface of the groove is A sealing type rolling bearing unit, wherein a sealing material is pressed on the basis of the elasticity of the core material, and the entire sealing ring is accommodated in the concave groove.   An outer ring having a double-row or multi-row outer ring raceway on the inner peripheral surface, an inner ring having a double-row or multi-row inner ring raceway on the outer peripheral surface, and between each outer ring raceway and each inner ring raceway, for each row A pair of rolling elements provided in a freely rotatable manner, and a pair of sliding contacts that block both axial openings of the rolling element installation space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. The inner ring includes a pair of inner ring elements each having one or more rows of the inner ring raceways on the outer peripheral surface thereof and abutting each other in the axial direction. Therefore, a concave groove is formed on the inner peripheral surface of the abutting portion between the axial end faces of both the inner ring elements, and is formed over the entire circumference in a state of spanning the two inner ring elements. A hermetic rolling bearing unit is assembled with a seal ring that tightly seals between the axial end faces of both inner ring elements. In this seal ring, which constitutes a ring, it is configured in a ring shape or a non-circular ring shape by an elastic material, and a seal material which is configured as a whole by a material having water and oil repellency, breathability and flexibility. In addition, by combining with a core material for reinforcing this seal material, the whole is configured in an annular shape, while the core material is elastically deformed while temporarily deforming the seal material, It can be attached to and detached from the groove after completion, and the sealing material is attached to the entire circumference of the portion corresponding to the inner ring elements on the bottom surface of the groove in a state assembled in the groove. A seal ring that is pressed on the basis of the elasticity of the core material and that fits entirely within the groove.

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