Annular seal, and manufacturing method for string-like seal material for annular seal

Abstract

To provide an annular seal capable of reducing manufacturing and easy to mount.SOLUTION: Rubber annular seals S1, S2 are provided with an annular lip part 3 on an inner diameter side or an outer diameter side of an annular base part 2 which bonds both ends of a string-like seal material 1 to make them annular. A string-like seal material 1 has a first engagement part A at one end and a second engagement part B at the other end, and becomes annular with the first engagement part A and the second engagement part B engaged. The first engagement part A and the second engagement part B have a shape cut through from an axial direction AD. Since there is no need to hold until adhesive has required adhesive strength after the adhesive is applied to both ends of the string-like seal material 1, no effort is necessary for fitting the annular seals S1, S2 to an outer ring and an inner ring. The shape is one that the first engagement part A and the second engagement part B are cut through from the axial direction AD, and it can be easily molded by a punch or the like, so that cost of manufacture does not increase.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an annular seal suitable for large-diameter rolling bearings such as slewing bearings for construction machinery, and to a method for manufacturing a string-like sealing material used in the annular seal. [Background technology]

[0002] Annular seals used in slewing bearings of construction machinery such as hydraulic excavators include those in which both ends of a string-shaped sealing material made by extruding rubber into a string shape with a predetermined cross-sectional shape are joined together (see, for example, Patent Documents 1 and 2).

[0003] The annular seal of Patent Document 1 is made by cutting the string-shaped sealing material to the required length, setting both ends of the string-shaped sealing material and a vulcanizable rubber material in a mold with the same cross section as the string-shaped sealing material, and heating the mold while pressing to cause a vulcanization reaction. As a result, both ends of the string-shaped sealing material are connected by the vulcanizable rubber material, forming a ring shape (paragraphs

[0024] and

[0025] and Figure 6 of Patent Document 1).

[0004] The annular seal of Patent Document 2 is made by cutting the string-shaped sealing material to the required length and then bonding both end faces of the string-shaped sealing material with an adhesive. As a result, both end faces of the string-shaped sealing material are bonded with the adhesive to form an annular shape (paragraphs

[0009] and

[0013] and Figure 3 of Patent Document 2). Furthermore, the annular seal of Patent Document 2 has a predetermined length portion (length L in Figure 3) sandwiching both end faces of the string-shaped sealing material bonded with an adhesive to the seal groove of the outer ring or inner ring to which the annular seal is attached (paragraphs

[0009] and

[0013] and Figure 3 of Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-61574 [Patent Document 2] Japanese Patent Application Publication No. 9-328777 Summary of the Invention [Problem to be solved by the invention]

[0006] The annular seal in Patent Document 1 requires the vulcanizable rubber material to be produced, as well as dedicated equipment such as the mold and heating device to vulcanize and bond the vulcanizable rubber material to both ends of the string-like sealing material, which makes the production of the annular seal time-consuming and increases the production costs.

[0007] Furthermore, it is necessary to use the dedicated device to vulcanize and bond the vulcanizable rubber material to both ends of the string-shaped sealing material to form endless annular seals, which must be attached to the outer ring and inner ring. Therefore, depending on the cross-sectional size of the annular seal, the structure and size of the slewing bearing, etc., it may not be possible to attach the annular seal to the outer ring and / or inner ring.

[0008] In manufacturing the annular seal in Patent Document 2, when joining both end faces of the string-shaped sealing material, it is necessary to hold the adhesive until it has the required adhesive strength, and it is also necessary to adhere a predetermined length of the annular seal that sandwiches both end faces into the seal groove. Therefore, manufacturing the annular seal and adhering the annular seal to the seal groove of the outer ring or inner ring is time-consuming and increases manufacturing costs.

[0009] An object of the present invention is to provide an annular seal that can be manufactured at low cost and that can be easily attached to the outer and inner rings of a rolling bearing, and to provide a method for manufacturing a string-shaped sealing material for an annular seal that can reduce manufacturing costs. [Means for solving the problem]

[0010] The annular seal according to a first aspect of the present invention is an annular seal made of rubber or thermoplastic elastomer, having an annular base and an annular lip formed by joining both ends of a string-shaped sealing material. The string-shaped sealing material has a first engaging portion at one end and a second engaging portion at the other end, and forms an annular shape when the first engaging portion and the second engaging portion are engaged. The first engaging portion and the second engaging portion are shaped to be cut through from the axial or radial direction.

[0011] According to the annular seal of the first aspect, the string-shaped sealing material is formed into an annular shape when the first engaging portion and the second engaging portion at both ends thereof are engaged, so that after applying adhesive to both ends of the string-shaped sealing material, it is not necessary to hold the adhesive in place until the adhesive has the required adhesive strength. Therefore, the work of attaching the annular seal to the outer ring and inner ring of the rolling bearing is not time-consuming.

[0012] Furthermore, after the string-shaped sealing material is wound around the seal groove of the outer or inner ring of the rolling bearing, the first and second engaging portions at both ends of the string-shaped sealing material can be engaged. Therefore, the annular seal can be used to meet various requirements for the cross-sectional shape and size of the annular seal, and for rolling bearings of various structures and sizes.

[0013] Furthermore, since the first engaging portion and the second engaging portion have a shape that allows them to be cut out from the axial direction or the radial direction, they can be easily formed using a punch or the like, and therefore the manufacturing cost does not increase.

[0014] An annular seal according to a second aspect of the present invention is the annular seal according to the first aspect, wherein the first engagement portion and the second engagement portion have opposing engagement surfaces that contact each other when engaged.

[0015] According to the annular seal of the second aspect, by applying adhesive to the engagement surfaces, the opposing engagement surfaces of the first engagement portion and the second engagement portion are adhered to each other, thereby firmly adhering both ends of the string-shaped sealing material.

[0016] The annular seal according to a third aspect of the present invention is the annular seal according to the first or second aspect, wherein the first engagement portion and the second engagement portion have a shape that allows them to be cut through from the axial direction, and when the first engagement portion and the second engagement portion are engaged with each other, they are prevented from coming off in the circumferential and radial directions.

[0017] A fourth aspect of the present invention is an annular seal according to the first or second aspect, wherein the first engagement portion and the second engagement portion are shaped to be cut through from the radial direction, and when the first engagement portion and the second engagement portion are engaged with each other, they are prevented from coming off in the circumferential and axial directions.

[0018] According to the annular seal of the third aspect, when the first engaging portion and the second engaging portion at both ends of the string-shaped sealing material are engaged, the string-shaped sealing material is prevented from coming off in the circumferential and radial directions, and according to the annular seal of the fourth aspect, when the first engaging portion and the second engaging portion at both ends of the string-shaped sealing material are engaged, the string-shaped sealing material is prevented from coming off in the circumferential and axial directions, so that the function of holding the string-shaped sealing material in an annular shape when the first engaging portion and the second engaging portion are engaged is even more reliable.

[0019] A manufacturing method of a string-shaped sealing material for an annular seal according to a fifth aspect of the present invention is a manufacturing method of a string-shaped sealing material for forming an annular seal made of rubber or thermoplastic elastomer, having an annular base portion and an annular lip portion. The string-shaped sealing material has a first engaging portion at one end and a second engaging portion at the other end, and becomes annular when the first engaging portion and the second engaging portion are engaged. The manufacturing method includes a step of extrusion-molding an intermediate molded body of the string-shaped sealing material, both end surfaces of which are flat, a first cutting-out step of cutting out one end of the intermediate molded body in the axial or radial direction to form the first engaging portion, and a second cutting-out step of cutting out the other end of the intermediate molded body in the axial or radial direction to form the second engaging portion.

[0020] According to the manufacturing method of the string-shaped sealing material for annular seals relating to the fifth aspect, the string-shaped sealing material for annular seals can be manufactured by a first cut-out process in which one end of an intermediate molded body of the string-shaped sealing material manufactured by extrusion molding is cut out in the axial direction, and a second cut-out process in which the other end of the intermediate molded body is cut out in the axial direction, so that the manufacturing costs of the string-shaped sealing material do not increase.

[0021] A sixth aspect of the present invention relates to a method for manufacturing a string-shaped sealing material for annular seals, and in the fifth aspect, the first cut-out step and the second cut-out step are carried out in the same process with both ends of the intermediate molded body overlapping each other.

[0022] According to the manufacturing method of the string-shaped sealing material for annular seals relating to the sixth aspect, the first cut-out process and the second cut-out process are carried out in the same process, and therefore the first engagement portion and the second engagement portion can be formed in the same cut-out process using a single punch or the like, thereby reducing the manufacturing cost of the string-shaped sealing material for annular seals. [Effects of the Invention]

[0023] As described above, the annular seal according to the present invention does not require much effort to mount on the outer or inner ring of a rolling bearing, can be used suitably for the outer and inner rings of rolling bearings of various structures and sizes, and does not increase manufacturing costs. Furthermore, the method for manufacturing the string-shaped sealing material for an annular seal according to the present invention does not increase manufacturing costs of the string-shaped sealing material. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is an enlarged longitudinal cross-sectional view of a main portion of a rotary bearing using an annular seal according to an embodiment of the present invention. [Figure 2] 2 is a perspective view showing only the annular seal, with components other than the annular seal omitted in the orbiting bearing of FIG. 1. FIG. [Figure 3A] 1 is a perspective view of an intermediate formed body of a string-shaped sealing material according to an embodiment of the present invention. [Figure 3B]3 is a view of the intermediate molded body as viewed from a direction perpendicular to the surface of the flat linear base portion. FIG. [Figure 4] 1A and 1B are views of a string-shaped sealing material according to an embodiment of the present invention, as viewed from a direction perpendicular to the surface of a flat, linear base portion; [Figure 5A] 10 is a perspective view showing the string-shaped sealing material being formed into a ring shape with the lip portion facing the inner diameter side. FIG. [Figure 5B] 5B is a perspective view showing a state in which the first engaging portion and the second engaging portion in FIG. 5A are engaged with each other to form an annular seal. FIG. [Figure 6A] 10 is a perspective view showing the string-shaped sealing material being formed into a ring shape with the lip portion facing outward. FIG. [Figure 6B] 6B is a perspective view showing a state in which the first engaging portion and the second engaging portion in FIG. 6A are engaged with each other to form an annular seal. FIG. [Figure 7] FIG. 3 is an enlarged perspective view showing a first engagement portion and a second engagement portion. [Figure 8A] 10 is an enlarged view of a main part, seen from the axial direction, showing a first modified example of the first engaging portion and the second engaging portion. FIG. [Figure 8B] 10 is an enlarged view of a main part, seen from the axial direction, showing a second modified example of the first engaging portion and the second engaging portion. FIG. [Figure 8C] 10 is an enlarged view of a main part, seen from the axial direction, showing a third modified example of the first engaging portion and the second engaging portion. FIG. [Figure 8D] 10 is an enlarged view of a main part, seen from the axial direction, showing a fourth modified example of the first engaging portion and the second engaging portion. FIG. [Figure 8E] 10 is an enlarged view of a main part, seen from the axial direction, showing a fifth modified example of the first engaging portion and the second engaging portion. FIG. [Figure 8F] 10 is an enlarged view of a main part, seen from the axial direction, showing a sixth modified example of the first engaging portion and the second engaging portion. FIG. [Figure 8G] 13 is an enlarged view of a main part of a seventh modified example of the first engaging portion and the second engaging portion as viewed from the axial direction. FIG. [Figure 8H] 13 is an enlarged view of a main part of an eighth modified example of the first engaging portion and the second engaging portion as viewed from the axial direction. FIG. [Figure 9A]This is a reference diagram showing an example of a method for forming a first engagement portion and a second engagement portion at both ends of the intermediate molded body, showing the moment of cutting with a punch.The upper figure is an enlarged view of the main part as seen from the axial direction, and the lower figure is an enlarged view of the main part as seen from the radial direction. [Figure 9B] FIG. 9A shows a state in which the cut pieces have been removed, with the upper figure being an enlarged view of the main part as seen from the axial direction, and the lower figure being an enlarged view of the main part as seen from the radial direction. [Figure 10] 1 is an enlarged longitudinal cross-sectional view of a main portion of a rotary bearing using an annular seal according to an embodiment of the present invention. [Figure 11A] 1 is a view of a string-shaped sealing material according to an embodiment of the present invention, viewed from a direction perpendicular to the surface of a flat linear base portion. [Figure 11B] 1 is a view of a string-shaped sealing material according to an embodiment of the present invention, viewed from a direction perpendicular to the surface of a flat linear base portion. [Figure 12A] 11B is a perspective view showing the string-shaped sealing material of FIG. 11A in the process of being formed into a ring shape with the lip portion on the lower side and the lip tip pointing toward the inner diameter side. FIG. [Figure 12B] 12B is a perspective view showing a state in which the first engaging portion and the second engaging portion in FIG. 12A are engaged with each other to form an annular seal. FIG. [Figure 13A] 11C is a perspective view showing the string-shaped sealing material of FIG. 11B in the process of being formed into a ring shape with the lip portion on the upper side and the lip tip pointing toward the outer diameter side. FIG. [Figure 13B] 13B is a perspective view showing a state in which the first engaging portion and the second engaging portion in FIG. 13A are engaged to form an annular seal. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0026] In this specification, the direction parallel to the direction of the central axis of rotation (symbol O in FIG. 2) of a rolling bearing (for example, slewing bearing 4 in FIG. 1) is called the "axial direction" (for example, see arrow AD in FIG. 2), and the direction perpendicular to the direction of the central axis of rotation is called the "radial direction" (for example, see arrow RD in FIG. 2). The "circumferential direction" (for example, see arrow CD in FIG. 2) is defined relative to the direction of the central axis of rotation.

[0027] [Slewing bearing] The slewing bearing 4 shown in Fig. 1 is used in construction machinery and is a large-diameter rolling bearing due to its structure. The slewing bearing 4 includes an outer ring 5, an inner ring 6, rolling elements 7, and annular seals S1 and S2 according to an embodiment of the present invention. The space in the slewing bearing 4 that houses the rolling elements 7 is filled with a lubricant.

[0028] [Annular seal] 1 and 2 are formed by joining both ends of a string-like sealing material 1 into a ring shape. The ring-shaped seal S1 has an annular lip portion 3 on the inner diameter side (inward in the radial direction RD) of the ring-shaped base portion 2, with the lip tip T facing downward. The ring-shaped seal S2 has an annular lip portion 3 on the outer diameter side (outward in the radial direction RD) of the ring-shaped base portion 2, with the lip tip T facing upward.

[0029] The annular seal S1 is fitted in a seal groove 8 formed in the inner circumferential surface 5A of the outer ring 5, and the annular seal S2 is fitted in a seal groove 9 formed in the outer circumferential surface 6A of the inner ring 6. The annular seal S1 seals an upper gap G1 between the outer ring 5 and the inner ring 6, and the annular seal S2 seals a lower gap G2 between the outer ring 5 and the inner ring 6.

[0030] As shown in Figure 2, the annular seals S1 and S2 are formed by engaging a first engagement portion A and a second engagement portion B provided at both ends of the string-shaped sealing material 1 to form an annular shape. The first engagement portion A and the second engagement portion B have complementary shapes that allow them to be cut out from the axial direction AD. When the first engagement portion A and the second engagement portion B are engaged, the string-shaped sealing material 1 becomes annular.

[0031] The annular seals S1 and S2 are made of rubber such as nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), chloroprene rubber (CR), ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), styrene-butadiene rubber (SBR), chlorosulfonated polyethylene rubber (CSM), acrylic rubber (ACM), fluororubber (FKM), and silicone rubber (VQM), or thermoplastic elastomer (TPE), and can be extruded.

[0032] [Step of forming an intermediate product of the string-shaped sealing material] 3A and 3B is manufactured by extrusion molding, and has a flat, linear base portion 11 and a linear lip portion 12. The intermediate molded body 10 is cut to the length required to form the annular seals S1 and S2, so both end faces D1 and D2 are flat.

[0033] [Step of forming a string-shaped sealing material from an intermediate formed body of the string-shaped sealing material] The shapes of the first engagement portion A and the second engagement portion B of the string-shaped sealing material 1 in Figure 4 are such that the first engagement portion A is concave and the second engagement portion B is convex, and they are approximately circular when viewed from a direction perpendicular to the surface of the flat linear base 11 (a direction perpendicular to the paper surface of Figure 4).

[0034] The string-shaped sealing material 1 shown in Fig. 4 is manufactured by a first cutting-out process in which one end 10A of the intermediate formed body 10 shown in Fig. 3B is cut out in a direction perpendicular to the surface of the flat linear base 11 (a direction perpendicular to the plane of the paper in Fig. 3B, the axial direction AD for the annular seals S1 and S2 in Figs. 5B and 6B, and the radial direction RD for the annular seals S3 and S4 in Figs. 12B and 13B) to form a first engagement portion A, and a second cutting-out process in which the other end 10B of the intermediate formed body 10 shown in Fig. 3B is cut out in the perpendicular direction to form a second engagement portion B. Therefore, the first engagement portion A at one end 1A of the string-shaped seal 1 and the second engagement portion B at the other end 1B are formed by cut surfaces 1C and 1D in the perpendicular direction shown in Fig. 4.

[0035] The string-shaped sealing material 1 for the annular seals S1, S2 is manufactured by a first cutting-out process in which one end 10A of the intermediate molded body 10 of the string-shaped sealing material 1 manufactured by extrusion molding is cut out in the vertical direction, and a second cutting-out process in which the other end 10B of the intermediate molded body 10 is cut out in the vertical direction, so the manufacturing cost of the string-shaped sealing material 1 is not increased.

[0036] [Process of turning string-shaped sealing material into annular seal] In Figures 5A and 5B, and Figures 6A and 6B, which will be referred to below, the cross-sectional size of the string-shaped sealing material 1 is exaggerated and shown larger than the actual length of the string-shaped sealing material 1 in order to make the drawings easier to see.

[0037] 4 is bent so that the direction of arrow E is concave, with the linear lip portion 12 facing inward. After passing through the configuration shown in FIG. 5A, when the first engaging portion A at one end 1A is engaged with the second engaging portion B at the other end 1B as shown in FIG. 5B, the string-shaped sealing material 1 becomes annular seal S1 having an annular lip portion 3 on the inner diameter side of the annular base portion 2.

[0038] The string-shaped sealing material 1 in Figure 4 is bent so that the direction of arrow F is concave, with the linear lip portion 12 facing outward. After passing through the form shown in Figure 6A, when the first engagement portion A at one end 1A is engaged with the second engagement portion B at the other end 1B as shown in Figure 6B, the string-shaped sealing material 1 becomes annular seal S2 having an annular lip portion 3 on the outer diameter side of the annular base portion 2. The annular seal S2 in the slewing bearing 4 in Figure 1 has a configuration obtained by flipping the annular seal S2 in Figure 6B upside down.

[0039] As shown in Figures 5B and 6B, in the annular seals S1, S2 in which the first engagement portion A and the second engagement portion B are engaged, the first engagement portion A and the second engagement portion B are prevented from coming loose in the circumferential direction CD and the radial direction RD due to the shapes of the first engagement portion A and the second engagement portion B, which are approximately circular when viewed from the axial direction AD.

[0040] 7, the engagement surface K of the first engagement portion A, which is formed by the cut surface 1C in the axial direction AD, and the engagement surface L of the second engagement portion B, which is formed by the cut surface 1D in the axial direction AD, are surfaces that face each other so as to come into contact when the first engagement portion A and the second engagement portion B are engaged. Therefore, by applying an adhesive to the engagement surfaces K, L, the engagement surfaces K, L that face each other when the first engagement portion A and the second engagement portion B are engaged are bonded together, and both end portions 1A, 1B of the string-shaped sealing material 1 are firmly bonded together.

[0041] [How to install an annular seal on a rolling bearing] The annular seals S1 and S2 can be attached to the rolling bearings by the following methods (1) to (3).

[0042] (1) First Method (a) An adhesive is applied to the cut surface 1C including the engaging surface K of the string-shaped sealing material 1 and the cut surface 1D including the engaging surface L. (b) The string-like sealing material 1 is wound around the seal groove of the rolling bearing (for example, seal grooves 8 and 9 in FIG. 1), and the annular base portion 2 other than both end portions is accommodated in the seal groove. (c) After the first engaging portion A and the second engaging portion B are engaged with each other, the annular base portions 2 at both ends are accommodated in the seal grooves.

[0043] (2) Second Method (a) The string-shaped sealing material 1 is wound around the seal groove of the rolling bearing (for example, the seal grooves 8 and 9 in FIG. 1), and the annular base portion 2 other than both end portions is accommodated in the seal groove. (b) An adhesive is applied to the cut surface 1C including the engaging surface K of the string-shaped sealing material 1 and the cut surface 1D including the engaging surface L. (c) After the first engaging portion A and the second engaging portion B are engaged with each other, the annular base portions 2 at both ends are accommodated in the seal grooves.

[0044] (3) Third Method (a) An adhesive is applied to the cut surface 1C including the engaging surface K of the string-shaped sealing material 1 and the cut surface 1D including the engaging surface L. (b) The first engaging portion A and the second engaging portion B are engaged to form the annular seals S1, S2 (for example, the configuration shown in FIG. 2). (c) The annular base portions 2 of the annular seals S1 and S2 are fitted into the seal grooves of the rolling bearing (for example, the seal grooves 8 and 9 in FIG. 1).

[0045] It is not essential to apply adhesive to the engagement surfaces K and L. Depending on the shapes of the outer and inner rings of the rolling bearing, adhesive may not be applied to the annular seals S1 and S2.

[0046] [Modifications of the first engaging portion and the second engaging portion] The first engaging portion A and the second engaging portion B are not limited to being substantially circular when viewed from a direction perpendicular to the surface of the flat linear base portion 11 (a direction perpendicular to the paper surface of FIG. 4) as shown in Fig. 4. The first engaging portion A and the second engaging portion B may have any shape that allows them to be cut out from the perpendicular direction and that allows the string-shaped sealing material 1 to be formed into a ring shape when the first engaging portion A and the second engaging portion B are engaged with each other.

[0047] Therefore, the first engagement portion A and the second engagement portion B can be formed in various shapes, such as the first modified example of Fig. 8A to the eighth modified example of Fig. 8H. In the first modified example of Fig. 8A to the seventh modified example of Fig. 8G, the first engagement portion A and the second engagement portion B are retained in the circumferential direction CD and the radial direction RD in the annular seals S1 and S2. In the eighth modified example of Fig. 8H, they are retained in the circumferential direction CD.

[0048] The first engaging portion A and the second engaging portion B are shaped so as to be prevented from coming off in the circumferential direction CD and the radial direction RD, which more reliably functions to hold the string-shaped sealing material 1 in an annular shape when the first engaging portion A and the second engaging portion B are engaged. However, depending on the required specifications for the annular seals S1, S2 and the location where they are used, it may be sufficient for the first engaging portion A and the second engaging portion B to be shaped so as to be prevented from coming off in the circumferential direction CD.

[0049] [Modification of the process of forming a string-shaped sealing material from an intermediate formed body of the string-shaped sealing material] 9A and 9B, the movement direction of the punch P is described as the axial direction AD. Figures 9A and 9B show an example in which, when forming the string-shaped sealing material 1 from the intermediate molding 10, both end portions 10A, 10B of the intermediate molding 10 are overlapped, and a first cut-out process of cutting out one end portion 10A of the intermediate molding 10 in the axial direction AD and a second cut-out process of cutting out the other end portion 10B of the intermediate molding 10 in the axial direction AD are performed in the same process.

[0050] That is, in a state where both end portions 10A, 10B of the intermediate compact 10 are overlapped, both end portions 10A, 10B are cut out with a punch P. As a result, cut pieces H1, H2 are cut off, and the first engaging portion and the second engaging portion B are formed.

[0051] By performing the first cut-out process and the second cut-out process in the same process in this way, the first engagement portion A and the second engagement portion B can be formed in the same cut-out process using a single punch P or the like, thereby reducing the manufacturing cost of the string-shaped sealing material 1 for the annular seals S1 and S2.

[0052] [Modification of annular seal] In Figure 10, the same reference numerals as in Figure 1 indicate the same or corresponding parts or portions and the same directions. Like the annular seals S1 and S2, the annular seals S3 and S4 are made of rubber or thermoplastic elastomer, and are formed by joining both ends of the string-shaped sealing material 1 into an annular shape.

[0053] The annular seal S3 has an annular lip portion 3 below the annular base portion 2, with the lip tip T facing inward. The annular seal S4 has an annular lip portion 3 above the annular base portion 2, with the lip tip T facing outward.

[0054] The annular seal S3 is fitted in a seal groove 8 formed in the lower surface 5B of the outer ring 5, and the annular seal S4 is fitted in a seal groove 9 formed in the upper surface 6B of the inner ring 6. The annular seal S3 seals a gap G3 on the outer diameter side between the outer ring 5 and the inner ring 6, and the annular seal S4 seals a gap G4 on the inner diameter side between the outer ring 5 and the inner ring 6.

[0055] The annular seals S3 and S4 are, for example, annular strips of sealing material 1 having the same cross-sectional shape as the annular seals S1 and S2. The cross-sectional shapes of the sealing material 1 in Figures 4, 11A, and 11B are the same.

[0056] [Process of turning string-shaped sealing material into annular seal] In Figures 12A and 12B, and Figures 13A and 13B referred to below, the cross-sectional size of the string-shaped sealing material 1 is exaggerated and shown larger than the actual length of the string-shaped sealing material 1 in order to make the drawings easier to see.

[0057] The string-shaped sealing material 1 in Fig. 11A is bent so that the center of the linear base 11 is on the front side of the page and the ends 1A and 1B are on the back side of the page, with the lip tip T on the inner diameter side. After passing through the form shown in Fig. 12A, when the first engagement portion A of one end 1A is engaged with the second engagement portion B of the other end 1B as shown in Fig. 12B, the string-shaped sealing material 1 becomes annular seal S3 having an annular lip portion 3 below the annular base 2.

[0058] 11B is bent so that the center of the linear base 11 is at the back of the page and the ends 1A and 1B are at the front of the page, with the lip tip T on the outer diameter side. After passing through the form shown in FIG. 13A, when the first engagement portion A of one end 1A is engaged with the second engagement portion B of the other end 1B as shown in FIG. 13B, the string-shaped sealing material 1 becomes annular seal S4 having an annular lip portion 3 above the annular base 2.

[0059] 12B and the annular seal S4 shown in Fig. 13B, the first engagement portion A and the second engagement portion B have complementary shapes that allow them to be cut through from the radial direction RD. In the annular seals S3 and S4, the first engagement portion A and the second engagement portion B are prevented from coming off in the circumferential direction CD and the axial direction AD, which further ensures the function of holding the string-shaped sealing material 1 in an annular shape when the first engagement portion A and the second engagement portion B are engaged.

[0060] [Summary of the shape of the annular seal made of string-like sealing material] The string-shaped sealing material 1 can be shaped as follows: (a) annular seal S1 having an annular lip portion 3 on the inner diameter side of an annular base 2 as shown in Fig. 5B, (b) annular seal S2 having an annular lip portion 3 on the outer diameter side of an annular base 2 as shown in Fig. 6B, (c) annular seal S3 having an annular lip portion 3 on the lower side of an annular base 2 with a lip tip T facing the inner diameter side as shown in Fig. 12B, or (d) annular seal S4 having an annular lip portion 3 on the upper side of an annular base 2 with a lip tip T facing the outer diameter side as shown in Fig. 13B. Shapes obtained by inverting any of (a) to (d) can also be used.

[0061] [Major effects of the annular seal according to the embodiment of the present invention] (1) Because the string-shaped sealing material 1 is formed into an annular shape when the first engaging portion A and the second engaging portion B at both ends are engaged, there is no need to hold the string-shaped sealing material 1 in place until the adhesive has the required adhesive strength after being applied to both ends. This eliminates the need for laborious work in attaching the annular seals S1 to S4 to the outer and inner rings of a rolling bearing (for example, the outer ring 5 and inner ring 6 in Figures 1 and 10).

[0062] (2) After the string-shaped sealing material 1 is wound around the seal groove of the outer or inner ring of the rolling bearing, the first engaging portion A and the second engaging portion B at both ends of the string-shaped sealing material 1 can be engaged. Therefore, the annular seals S1 to S4 can be suitably used for various required specifications for the cross-sectional shape and size, as well as for rolling bearings of various structures and sizes.

[0063] (3) Since the first engaging portion A and the second engaging portion B have a shape that allows them to be cut out in the axial direction AD or the radial direction RD, they can be easily formed using a punch or the like, and therefore the manufacturing cost does not increase.

[0064] The above description of the embodiments is given by way of example only and is not intended to be limiting, and various improvements and modifications can be made without departing from the scope of the present invention. [Explanation of symbols]

[0065] 1 String-shaped sealing material 1A One end 1B Other end 1C,1D Cutting surface 2 Annular base 3 Annular lip 4 Slewing bearing 5 Outer ring 5A Inner surface 5B Bottom surface 6 Inner ring 6A Outer surface 6B Upper surface 7 Rolling element 8, 9 Seal groove 10 Intermediate molding 10A One end 10B Other end 11 Straight base portion 12 Straight lip portion A First engagement part AD Axial direction B Second engaging part CD Circumferential direction D1,D2 End face E,F direction G1,G2,G3,G4 Gap H1,H2 Cut piece K, L Engagement surface O Bearing rotation axis P punch RD radial direction S1, S2, S3, S4 Annular seal T Lip tip

Claims

1. An annular seal made of rubber or a thermoplastic elastomer, having an annular base portion and an annular lip portion, formed by joining both ends of a string-like sealing material, the string-shaped sealing material has a first engaging portion at one end and a second engaging portion at the other end; The first engaging portion and the second engaging portion are in an engaged state, and the first engaging portion and the second engaging portion are in an annular shape. The first engaging portion and the second engaging portion have a shape that allows them to be cut through from an axial direction or a radial direction. Circular seal.

2. The first engagement portion and the second engagement portion have opposing engagement surfaces that contact each other when engaged. The toric seal of claim 1 .

3. the first engaging portion and the second engaging portion have a shape that allows them to be cut through from the axial direction, When the first engaging portion and the second engaging portion are engaged with each other, they are prevented from coming off in the circumferential direction and the radial direction.

3. The annular seal according to claim 1 or 2.

4. the first engaging portion and the second engaging portion have a shape that allows them to be cut out from a radial direction, When the first engaging portion and the second engaging portion are engaged with each other, they are prevented from coming off in the circumferential direction and the axial direction.

3. The annular seal according to claim 1 or 2.

5. 1. A method for manufacturing a string-shaped sealing material for forming an annular seal made of rubber or thermoplastic elastomer, the annular seal having an annular base portion and an annular lip portion, comprising: the string-shaped sealing material has a first engaging portion at one end and a second engaging portion at the other end, and is annular in shape when the first engaging portion and the second engaging portion are engaged with each other; a step of extruding an intermediate formed body of the string-shaped sealing material, the intermediate formed body having flat end surfaces; a first cutting step of cutting out one end of the intermediate formed body in an axial or radial direction to form the first engaging portion; a second cutting step of cutting out the other end of the intermediate molded body in the axial or radial direction to form the second engaging portion; having A method for manufacturing a string-shaped sealing material for annular seals.

6. The first cut-out step and the second cut-out step are performed in the same step with both end portions of the intermediate molded body overlapped. A method for producing the string-shaped sealing material for annular seals according to claim 5.

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