Joint body and elastic shaft joint using the same

Abstract

To provide a joint body capable of being used under higher rotation while maintaining safety, and an elastic shaft joint using the joint body.SOLUTION: A joint body 1 is formed of a rubber-like elastic body in which a reinforcing cord layer 2 is embedded, and formed into a cylindrical shape. The joint body 1 comprises a curved part 11 that is curved in an arch shape outward in a radial direction R, side wall parts 12 that are connected to both sides of the curved part 11 in a central axis C direction and extend in the radial direction R, and an edge part 13 that extends outward in the central axis C direction from the side wall parts 12, where a bead core 6 is embedded in the radial direction R inside a radial center 12a of the side wall parts 12, and outside the reinforcing cord layer 2.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a coupling body made of a rubber-like elastic material having a reinforcing cord layer reinforced by a reinforcing cord, and to an elastic coupling using the same, for use in, for example, an elastic coupling for transmitting torque from a drive shaft to a driven shaft. [Background technology]

[0002] A shaft coupling is often used at the connection between the drive shaft and the driven shaft to transmit torque from the drive shaft to the driven shaft. For this shaft coupling, an elastic shaft coupling having a coupling body made of a rubber-like elastic material is often used for the purpose of mitigating shock, attenuating vibration, and absorbing installation errors of the drive shaft and the driven shaft, and torque is transmitted via the coupling body.

[0003] A joint body used in an elastic shaft joint is known to have the same structure as an automobile tire. In such a joint body, as shown in FIG. 1 of Patent Document 1, the bolt mounting annular fittings 2a and 2b must be inserted into a tire-shaped joint body 3 (rubber tire), and the work requires considerable effort. In particular, when the joint body 3 becomes large in size, the weight of the joint body 3 and the bolt mounting annular fitting 2 becomes heavy, making the work difficult. In addition, the joint body 3 incorporating the mounting annular fitting 2 is interposed between a pair of flanges 1a and 1b fixed to the end of the rotating shaft 8a and the end of the rotating shaft 8b, but when replacing the joint body 3, it is necessary to shift the positions of the flanges 1a and 1b and remove the joint body 3. Therefore, it is necessary to adjust the positions of the flanges 1a and 1b again, which increases the work required for replacing the joint body.

[0004] In order to solve the above problem, as shown in Figs. 2 and 3 of Patent Document 2, an elastic shaft coupling is known that is made of a rubber-like elastic body formed in a substantially cylindrical shape and has a cutout portion 3d in which the rubber-like elastic body is cut out in the radial direction at one location in the circumferential direction. Specifically, the elastic shaft coupling includes a pair of flanges 2A and 2B fixed to the end of a rotating shaft 1A and the end of a rotating shaft 1B, and a joint body 3 that connects the pair of flanges 2A and 2B. The joint body 3 is made of a rubber-like elastic body having a laminated structure in which a plurality of reinforcing cords made of rubber-topped tire cords 3C made of nylon or the like are layered between inner and outer rubber layers 3A and 3B made of natural rubber in order to increase rigidity (see paragraph 0014 of Patent Document 2). The joint body 3 includes a curved portion that is curved in an arch shape radially outward, side wall portions that are connected to both sides of the curved portion in the central axial direction and extend in the radial direction, and an edge portion that extends outward in the central axial direction from the side wall portions.

[0005] When the joint body having the above configuration is mounted on the pair of flanges 2A and 2B, the gap of the cut-out portion 3d of the joint body 3 is largely expanded and the joint body 3 is placed over the pair of flanges 2A and 2B. Then, the gap of the cut-out portion 3d is returned to its original state, and both ends of the joint body 3 in the central axis direction are sandwiched and fixed between the flange 2A or 2B and the pressure ring 6. More specifically, the pressure ring 6 is formed so that the portion of the abutting surface abutting the side wall portion that abuts the radial center of the side wall portion is the frontmost portion closest to the flange 2A or 2B. Here, the radial center of the side wall portion is approximately the central region of the region obtained by dividing the radial length of the side wall portion into three equal parts in the radial direction. By firmly sandwiching the radial center of the side wall portion between the frontmost portion of the pressure ring 6 and the flange, the radial inner portion of the side wall portion is prevented from falling off from between the frontmost portion and the flange. This makes it possible to mount and remove the joint body 3 without moving the positions of the pair of flanges 2A and 2B. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2000-220656 A [Patent Document 2] Japanese Patent Application Publication No. 10-318275 Summary of the Invention [Problem to be solved by the invention]

[0007] The above-mentioned joint body is fixed by being sandwiched between the flange and the pressure ring, but the surface pressure that the joint body receives from the flange and the pressure ring may decrease due to aging deterioration of the joint body, etc. In this state, if centrifugal force or excessive torque due to high-speed rotation is applied to the joint body, there is a risk that both ends in the central axis direction of the joint body near the cutout part will fall off from between the flange and the pressure ring. Therefore, in an elastic shaft coupling using a joint body having a cutout part, it was necessary to set the operating speed low to ensure safety. Also, in an elastic shaft coupling using a joint body without a cutout part, the surface pressure that the joint body receives from the bolt mounting ring and the flange may decrease due to aging deterioration of the joint body, etc. In that case, the central axis of the joint body may deviate from the central axis of the elastic shaft coupling, causing vibration and reducing safety.

[0008] Therefore, an object of the present invention is to provide a joint body that can be used under higher speed rotation while maintaining safety, and an elastic shaft joint using the same. [Means for solving the problem]

[0009] In order to solve the above problems, one aspect of the present invention provides a joint body formed into a cylindrical shape and made of a rubber-like elastic body in which a reinforcing cord layer is embedded, The joint body includes a curved portion curved in an arch shape radially outward, a side wall portion connected to both sides of the curved portion in a central axial direction and extending in the radial direction, and an edge portion extending outward in the central axial direction from the side wall portion, A bead core is embedded radially inward from the radial center of the side wall portion and outside the reinforcing cord layer.

[0010] The bead core may be disposed at a corner portion between the side wall portion and the edge portion.

[0011] The bead core may be configured by arranging a plurality of twisted cords each formed by twisting a plurality of steel filaments together.

[0012] The filament diameter may be 0.15 mm to 0.20 mm, and the twisted cord diameter may be 1.0 mm to 1.3 mm.

[0013] The joint body may be configured such that a cutout portion is provided at one location in a circumferential direction by cutting out the joint body in a radial direction.

[0014] Elastic couplings include: A pair of flanges attached to the ends of the drive shaft and the driven shaft in opposing relation to each other; a joint body having the cutout portion and spanning the pair of flanges; a pressure ring that holds the side wall portion and the edge portion between the pressure ring and the flange, The pressure ring may be configured so that the front end portion of the contact surface that contacts the side wall portion, closest to the flange, is located at the portion that contacts radially outward from the radial center of the side wall portion.

[0015] In addition, in the elastic shaft coupling, the bead core may be positioned at a position where the front end portion radially overlaps with at least a portion of the bead core with the side wall portion and the edge portion clamped between the flange and the pressure ring.

[0016] The contact surface may be formed in a radially convex shape, with the tip end portion being an apex of the convex shape. Effect of the Invention

[0017] For both axial ends of the joint body to fall out from between the flange and the pressure ring, or for the central axis of the joint body to deviate from the central axis of the elastic shaft coupling, a part of the joint body that is radially inward relative to the radial center of the side wall portion must deform and move outward, passing between the tip of the pressure ring and the flange.

[0018] According to one aspect of the present invention, a bead core with high rigidity is embedded radially inward of the radial center of the side wall of the joint body and outside the reinforcing cord layer. As a result, when the part of the joint body radially inward of the radial center of the side wall tries to pass between the front end of the pressure ring and the flange while deforming, the bead core functions as a stopper, and it is possible to effectively prevent both ends of the joint body in the central axis direction near the cutout from falling out from between the flange and the pressure ring, or to prevent the central axis of the joint body from shifting from the central axis of the elastic shaft coupling. Therefore, according to the above aspect, it is possible to provide a joint body that can be used under higher speed rotation while maintaining safety, and an elastic shaft coupling using the same. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a plan view showing a joint body of the present embodiment; [Diagram 2] Enlarged cross section of Fig. 1 along line AA [Diagram 3] FIG. 1 is a cross-sectional view showing an elastic shaft coupling using the coupling body of the present embodiment. [Figure 4] Cross-sectional view showing an example of a bead wire [Diagram 5] FIG. 1 is a cross-sectional view showing another example of a bead wire. [Figure 6] FIG. 11 is a plan view showing a modified example of the joint body of the present embodiment. [Figure 7] FIG. 11 is an enlarged cross-sectional view showing another modified example of the joint body of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a joint body 1 in this embodiment, and FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. As shown in the drawings, the joint body 1 in this embodiment is made of a rubber-like elastic body in which a reinforcing cord layer 2 is embedded. More specifically, the joint body 1 includes an inner rubber layer 3, a reinforcing cord layer 2, and an outer rubber layer 4. In this specification, the side closer to the central axis C of the joint body 1 along the radial direction R is referred to as the "radial inner side", and the side farther from the central axis C is referred to as the "radial outer side". In addition, the side closer to the equatorial plane CL (see FIG. 2) of the joint body 1 along the central axis C is referred to as the "central axis inner side", and the side farther from the equatorial plane CL is referred to as the "central axis outer side".

[0021] The joint body 1 is formed in a generally cylindrical shape having, at one location in the circumferential direction, a cut-out portion 5 obtained by cutting the joint body 1 in the radial direction. The joint body 1 includes a curved portion 11 curved in an arch shape radially outward, side wall portions 12 connected to both sides in the direction of the central axis C of the curved portion 11 and extending radially inward, and an edge portion 13 extending outward in the direction of the central axis C from the radially inner end portion of the side wall portion 12.

[0022] 2, the radial length L12 of the side wall portion 12 is the length from the radial outer peripheral end 13a at the outer end of the edge portion 13 in the direction of the central axis C to the connection position of the side wall portion 12 and the curved portion 11, i.e., the position where the curvature of the curved portion 11 begins. In the present invention, the bead core 6 is embedded in a region 4a of the outer rubber layer 4 on the outer side of the reinforcing cord layer 2, radially inward from the radial center 12a of the side wall portion 12, which is the middle position of the length L12 of the side wall portion 12.

[0023] 3 is a cross-sectional view showing an elastic shaft coupling using the joint body 1 of this embodiment. The elastic shaft coupling includes a pair of flanges 23 and 24 fixed to the end of the drive shaft 21 and the end of the driven shaft 22 in a facing relationship, a joint body 1 made of a rubber-like elastic body connecting the pair of flanges 23 and 24, and pressure rings 25, 25 that hold the side wall portion 12 and the edge portion 13 between the flanges 23 or 24. The pressure rings 25, 25 are disposed on the outer side of the flanges 23, 24 in the direction of the central axis C. In this figure, the central axis C of the joint body 1 coincides with the central axis of the elastic shaft coupling, i.e., the central axes of the flanges 23 and 24, the pressure ring 25, the drive shaft 21, and the driven shaft 22.

[0024] The pressure ring 25 is usually formed so that the front end 25a closest to the flange 23 or 24 is located in the portion of the contact surface that contacts the side wall portion 12 and that contacts radially outward from the radial central portion 12b of the side wall portion 12. This is because the radially inner portion of the radial central portion 12b of the side wall portion 12 is a portion where the thickness in the direction of the central axis C changes greatly, and therefore if the pressure ring 25 is formed so that the front end 25a is located in this portion, it becomes difficult to stably and firmly clamp the joint body 1.

[0025] On the other hand, the thickness in the direction of the central axis C is formed to be almost constant from the radial center portion 12b of the side wall portion 12 to the radial outside. Therefore, by abutting the front end portion 25a at this portion, the joint body 1 can be stably and firmly clamped by the pressure ring 25 and the flange 23 or 24. In this embodiment, the pressure ring 25 is formed so that the front end portion 25a is located at the portion abutting against the radial center portion 12b of the side wall portion 12. The above configuration is preferable in that it is possible to suppress the increase in size of the flanges 23, 24 and the pressure ring 25, thereby reducing the weight of the elastic shaft joint. The region of the radial center portion 12b of the side wall portion 12 is approximately the central region of the region obtained by dividing the radial length L12 of the side wall portion 12 into three equal parts in the radial direction R.

[0026] In this embodiment, the cross-sectional shape of the contact surface of the pressure ring 25 is formed in a substantially triangular convex shape, and the apex of the convex shape is the foremost part 25a. In this case, the foremost part 25a is formed in a linear and annular shape. The cross-sectional shape of the contact surface is not particularly limited, and may be formed in a trapezoidal shape, for example, and the foremost part 25a may be formed in a planar and annular shape. In addition, the apex of the substantially triangular convex shape may be rounded to make the foremost part 25a curved. However, it is preferable to form the cross-sectional shape of the contact surface of the pressure ring 25 in a substantially triangular shape, since the tightening force of the pressure ring 25 can be more concentrated on the foremost part 25a.

[0027] When the joint body 1 is attached to the pair of flanges 23 and 24, the joint body 1 is set so as to straddle the pair of flanges 23 and 24 while greatly expanding the gap of the cut-out portion 5 of the joint body 1. After the joint body 1 is stretched across the pair of flanges 23 and 24, the gap of the cut-out portion 5 is returned to its original state. Then, the side wall portion 12 and the edge portion 13 of the joint body 1 are sandwiched between the pressure ring 25 and the flange 23 or 24, and the fastening member 26 is tightened to fix the joint body 1 to the flanges 23 and 24. Note that FIG. 3 shows a state in which the pressure ring 25 is tightened by the fastening member 26 only on the flange 24 side.

[0028] More specifically, the radial center portion 12b of the side wall portion 12 is tightly sandwiched between the front end portion 25a of the compression ring 25 and the flange 23 or 24, thereby preventing the portion of the joint body 1 that is radially inward from the radial center portion 12b of the side wall portion 12 from falling off between the front end portion 25a and the flange 23 or 24. This makes it possible to attach and detach the joint body 1 without moving the positions of the pair of flanges 23 and 24.

[0029] In the elastic shaft coupling of the above configuration, for the coupling body 1 near the cut-out portion 5 to fall out from between the flange 23 or 24 and the pressure ring 25, it is necessary for the portion of the coupling body 1 that is radially inward of the front end portion 25a, i.e., the portion that is radially inward of the radial central portion 12b of the side wall portion 12, to move outward while deforming and pass through the narrow space between the front end portion 25a of the pressure ring and the flange 23 or 24.

[0030] In the present invention, the bead core 6 is embedded in the region 4a of the outer rubber layer 4 radially inward of the radial center 12a of the side wall portion 12 of the joint body 1 and on the outside of the reinforcing cord layer 2. Therefore, in order for the joint body 1 in the vicinity of the cutout portion 5 to fall out between the flange 23 or 24 and the pressure ring 25, the bead core 6 must pass through the narrow space between the tip portion 25a and the flange 23 or 24. At this time, the bead core 6 with high rigidity functions as a stopper. Furthermore, by replacing a part of the rubber in the region 4a of the outer rubber layer 4 with the bead core 6 which is highly rigid and difficult to deform, the deformation of the rubber in the region 4a is limited, and it is possible to effectively prevent the joint body 1 in the vicinity of the cutout portion 5 from falling out between the flange 23 or 24 and the pressure ring 25. This makes it possible to use the elastic shaft coupling under higher speed rotation while maintaining safety.

[0031] The bead core 6 may be disposed at any position radially inward of the radial center 12a of the side wall 12 and within the region 4a of the outer rubber layer 4 on the outer side of the reinforcing cord layer 2. However, it is preferable to dispose the bead core 6 at a position that does not affect the elastic deformation of the outer rubber layer 4 caused by the pressure contact of the front end portion 25a when the pressure ring 25 is fastened by the fastening member 26. In this way, when the front end portion 25a is pressure-contacted to the side wall 12, the outer rubber layer 4 undergoes large elastic deformation, so that the front end portion 25a is held in a state where it penetrates deep into the side wall 12, and it becomes possible to more effectively prevent the joint body 1 from falling off from between the flange 23 or 24 and the pressure ring 25.

[0032] A preferred position for the bead core 6 that does not affect the elastic deformation of the outer rubber layer 4 due to the pressure welding of the front end 25a when the compression ring 25 is tightened is radially inward of the radial center 12b of the side wall 12, i.e., radially inward of a position radially outward by a length of (L12 / 3) from the radial outer circumferential end 13a of the edge 13, and in the region 4b of the outer rubber layer 4 on the outside of the reinforcing cord layer 2. By embedding the bead core 6 in the region 4b away from the radial center 12b of the side wall 12, it becomes possible to firmly clamp the joint body 1 without affecting the elastic deformation of the outer rubber layer 4.

[0033] 2 and 3, it is more preferable to dispose the bead core 6 in the corner between the side wall 12 and the edge 13, i.e., in the corner where the reinforcing cord layer 2 extending in the radial direction R in the side wall 12 turns toward the central axis C. By disposing the bead core 6 in this position, it is possible to easily position the bead core 6 and achieve a stable function as a stopper, and it is possible to more effectively prevent the joint body 1 from falling off between the flange 23 or 24 and the pressure ring 25 without affecting the elastic deformation of the outer rubber layer 4 when the joint body 1 is tightened by the compression ring 25.

[0034] It is preferable to position the bead core 6 so that the front end 25a overlaps at least a part of the bead core 6 in the radial direction R with the side wall portion 12 and the edge portion 13 sandwiched between the flange 23 or 24 and the pressure ring 25. If the bead core 6 is positioned in this position, the bead core 6 will interfere with the front end 25a when a portion of the joint body 1 radially inward of the radial center portion 12b of the side wall portion 12 attempts to pass between the front end 25a of the pressure ring 25 and the flange 23 or 24. Therefore, the function as a stopper can be more effectively exerted.

[0035] The bead core 6 is composed of a plurality of rubber-coated bead wires 7. The bead wires 7 can be formed of a single wire or a twisted wire (twisted cord). The bead wires 7 are made of a material that is more rigid than the rubber constituting the outer rubber layer 4, that is, is less likely to deform. Specifically, metals such as steel, synthetic resins such as rayon, nylon, polyester, and aramid, and carbon fibers can be used. The ratio of the total cross-sectional area of ​​the plurality of bead wires 7 to the cross-sectional area of ​​the region 4a in FIG. 2 may be 15% or more, preferably 20% or more, from the viewpoint of exerting the function as a stopper, and may be 50% or less, preferably 40% or less, from the viewpoint of moldability of the joint body 1. Here, the cross-sectional area of ​​the bead wires 7 means the area surrounded by the two-dot chain line indicated by the symbol 7 as shown in FIG. 4 or FIG. 5.

[0036] The bead core 6 of the present invention does not require the same level of properties as those required for bead cores of automobile tires used in high-pressure environments, such as modulus and bending rigidity. Therefore, in order to make it easier to widen the gap at the cut-out portion 5, it is preferable to use a twisted cord made by twisting together a plurality of steel filaments as the bead wire 7. The steel twisted cord preferably has a filament diameter of 0.15 mm to 0.20 mm and a twisted cord diameter of 1.0 mm to 1.3 mm. The pitch of the twisted cord is preferably about 12 mm to 14 mm.

[0037] By setting the above range, the steel twisted cord can exhibit excellent flexibility (the bending rigidity can be reduced). That is, even though two bead cores 6, 6 are arranged near both edges 13, 13 of the joint body 1, it is possible to widen the gap between the cut-out portions 5 by the same operation as in a conventional joint body that does not use a bead core 6.

[0038] 4 is a cross-sectional view showing an example of a bead wire 7 used in this embodiment. The bead wire 7 has a 1×3+5×7+1 configuration including one core strand 9 formed by S-twisting three steel filaments 8, five side strands 10 formed by S-twisting seven steel filaments 8, and one wrapping wire 15. The five side strands 10 are twisted around the core strand 9 in a Z-twist. The wrapping wire 15 is S-twisted.

[0039] 5, it is also possible to use a 5×7+1 configuration with only side strands 10 and wrapping wire 15 without using the core strand 9. A 1×3+5×7 configuration without using the wrapping wire 15 or a twisted cord with a 5×7 configuration can also be used without any problems, but using the wrapping wire 15 has the advantage that the bending repulsive force can be reduced, so that when the joint body 1 is in its natural state, the cutout portion 5 is less likely to open.

[0040] In addition, because automobile tires are required to have pressure resistance, the bead core 6 is arranged so as to be surrounded by the folded-back reinforcing cord layer, but in the present invention, the bead core 6 is embedded in the outer rubber layer 4 on the outside of the reinforcing cord layer 2. In other words, by locating the bead core 6 as close to the forefront portion 25a as possible, it is possible to effectively prevent both ends in the central axial direction of the joint body 1 near the cut-out portion 5 from falling out from between the flange 23 or 24 and the compression ring 25.

[0041] Furthermore, due to the difference in the configuration described above, the productivity in manufacturing the joint body of the present invention can be at the same level as in manufacturing a joint body having a conventional cutout portion. The reason for this will be explained below.

[0042] When manufacturing a joint body having a conventional cutout portion, a long, thin, strip-shaped unvulcanized rubber sheet is wrapped around the outer periphery of a rotary mold (core mold) having a shape that matches the shape of the joint body 1, and then cut. The unvulcanized rubber sheet is then pressed against the core mold to be shaped to fit the core mold to some extent, and then, while rotating the core mold, a disk-shaped rotating roller called a stitcher is pressed against the surface of the inner rubber sheet to bring the unvulcanized rubber sheet into close contact with the core mold. This forms an unvulcanized inner rubber layer.

[0043] Next, the unvulcanized reinforcing cord sheet, in which the reinforcing cord is topped with unvulcanized rubber, is cut into a long and thin strip, and is laminated on the unvulcanized inner rubber layer with the cut surfaces aligned in the same manner as described above. By repeating this operation, a plurality of unvulcanized reinforcing cord layers are formed on the unvulcanized inner rubber layer. Thereafter, a long and thin unvulcanized rubber sheet is laminated on the unvulcanized reinforcing cord layer in the same manner as described above. By the above operation, the unvulcanized inner rubber layer, the reinforcing cord layer, and the outer rubber layer are laminated on the core mold, and a preformed unvulcanized rubber-like elastic body can be obtained. The preformed unvulcanized rubber laminate obtained in the above manner is removed from the core mold and then vulcanized and molded in a mold to obtain a joint body.

[0044] When manufacturing the joint body 1 of the present invention, after forming the unvulcanized reinforcing cord layer, a plurality of bead wires 7 covered with unvulcanized rubber may be arranged at predetermined positions on the unvulcanized reinforcing cord layer before laminating the unvulcanized rubber sheet that constitutes the outer rubber layer 4. As described above, the joint body 1 of the present invention has a simple structure, so production defects are unlikely to occur, and it is possible to maintain productivity equivalent to that of conventional joint bodies.

[0045] In this embodiment, the bead core 6 has a substantially rectangular cross section and is made of a total of 18 bead wires 7, which are formed by laminating three layers of flat cord-like bodies, each of which is made of six bead wires 7 topped with unvulcanized rubber. The cross section of the bead core 6 is not particularly limited, but considering the function as a stopper, it is preferable that the bead core 6 has an angular shape that makes it difficult for the bead core 6 to pass through the space between the tip portion 25a and the flange 23 or 24.

[0046] The reinforcing cord layer 2 is composed of a rubber-topped reed woven fabric (reinforcing cord). Examples of fibers used for the reinforcing cord include organic fibers such as rayon, nylon, polyester, aramid, and carbon, and inorganic and metallic fibers such as glass and steel. The number of layers of the reinforcing cord layer 8 is determined appropriately according to the rigidity required for the joint body 1. In general, a layer of 2 to 10 layers is preferably used. In this embodiment, the reinforcing cord layer 2 is made up of 8 layers.

[0047] There is no particular limitation on the base compounding of the rubber used in the inner rubber layer 3, the reinforcing cord layer 2, and the outer rubber layer 4, and any compounding that has been conventionally known in this field can be used. For example, natural rubber (NR), which is excellent in abrasion resistance, water resistance, and processability, or a blend compounding composition of NR with cis-1,4-polybutadiene rubber (BR) and / or SBR can be mentioned. The base compounding of the rubber of each layer may be the same or different.

[0048] In the above embodiment, the joint body 1 is described as a type having a cutout portion 5, but the present invention is not limited to this, and may be a type having no cutout portion. Specifically, in Figs. 1 and 2, the cutout portion 5 may not be formed (hereinafter, for convenience, the same reference numerals are used to denote the same members as in the above embodiment). Fig. 6 shows a plan view of the joint body 1 having no cutout portion. The enlarged cross-sectional view of the joint body 1 shown in Fig. 6 is the same as Fig. 2. That is, the joint body 1 is made of a rubber-like elastic body having a reinforcing cord layer 2 embedded therein, and is formed into a cylindrical shape. The joint body 1 includes a curved portion 11 curved in an arch shape radially outward, side wall portions 12 connected to both sides of the curved portion 11 in the direction of the central axis C and extending in the radial direction, and an edge portion 13 extending outward from the side wall portion 12 in the direction of the central axis C. The bead core 6 is embedded radially inward of the radial center 12a of the side wall portion 12 and outside the reinforcing cord layer 2.

[0049] When using a joint body 1 that does not have a cutout portion 5, the joint body 1 is fixed by a bolt-mounted annular fitting and a flange as described in Patent Document 1 (JP Patent Publication 2000-220656 A). The shape of this flange may be formed to be similar to that of the compression ring 25 used in the elastic shaft joint of the present invention. In other words, the flange may be shaped so that the front end closest to the bolt-mounted annular fitting is formed in the portion of the abutment surface where the flange abuts against the side wall portion 12 of the joint body 1 that abuts radially outward from the radial center portion 12b of the side wall portion 12.

[0050] In the above elastic shaft coupling, even if the surface pressure that the joint body 1 receives from the bolt mounting annular fitting and the flange decreases due to aging or the like of the joint body 1, the central axis C of the joint body 1 is prevented from shifting from the central axis of the elastic shaft coupling, thereby suppressing vibration. This makes it possible to provide a joint body 1 and an elastic shaft coupling using the same that can be used under higher speed rotation while maintaining safety.

[0051] The bead core 6 may be arranged in a corner portion between the side wall portion 12 and the edge portion 13. By arranging the bead core 6 in this position, the bead core 6 can be easily positioned and can stably function as a stopper, and it is possible to effectively prevent the central axis C of the joint body 1 from shifting without affecting the elastic deformation of the outer rubber layer 4 when the joint body 1 is tightened by the flange.

[0052] The bead core 6 may also be configured to have a plurality of twisted cords each made of a plurality of steel filaments twisted together. This can prevent the central axis C of the joint body 1 from shifting, and allows the bolt attachment ring to be inserted into or removed from the joint body 1 smoothly. Furthermore, it is preferable that the filament diameter is 0.15 mm to 0.20 mm, and the twisted cord diameter is 1.0 mm to 1.3 mm. This can allow the bolt attachment ring to be inserted into or removed from the joint body 1 more smoothly.

[0053] Although the embodiment of the present invention has been described above, the scope of the present invention is not limited thereto, and various modifications can be made without departing from the spirit of the invention. Specifically, in this embodiment, the joint body 1 is formed so that the edge portion 13 extends only outward in the direction of the central axis C, but it is also possible to form it so that it extends both outward and inward in the direction of the central axis C, as shown in FIG.

[0054] The constituent elements disclosed in the present embodiment can be combined with each other, and by combining them, new technical features can be formed. [Explanation of symbols]

[0055] 1 Fitting body 11 Curved section 12 Side wall 12a Radial center 12b Radial center of side wall 13 Edge 13a: Radial outer periphery at the central axial outer end of the edge 2 Reinforcing cord layer 3 Inner rubber layer 4 Outer rubber layer 5 Excision part 6 Bead Core 7 Bead wire 8 Filaments 9 core strand 10 Side Strands 15 Wrapping Wire 21 Drive shaft 22 Driven axis 23 Flange 24 Flange 25 Pressure Ring 26 Fastening members

Claims

1. A joint body made of a rubber-like elastic body in which a reinforcing cord layer is embedded and formed into a cylindrical shape, The joint body includes a curved portion curved in an arch shape radially outward, a side wall portion connected to both sides of the curved portion in a central axial direction and extending in the radial direction, and an edge portion extending outward in the central axial direction from the side wall portion, a joint body, the joint body having a bead core embedded radially inward from a radial center of the side wall portion and outside the reinforcing cord layer;

2. The joint body according to claim 1 , wherein the bead core is disposed at a corner portion between the side wall portion and the edge portion.

3. 2. The joint body according to claim 1, wherein the bead core is formed by arranging a plurality of twisted cords each having a plurality of steel filaments twisted together.

4. 4. The coupling body of claim 3, wherein the filament diameter is between 0.15 mm and 0.20 mm, and the twisted cord diameter is between 1.0 mm and 1.3 mm.

5. The joint body according to any one of claims 1 to 4, wherein a cutout portion is provided in one circumferential location of the joint body by cutting out the joint body in a radial direction.

6. A pair of flanges attached to the ends of the drive shaft and the driven shaft in opposing relation to each other; A joint body according to claim 5 that is stretched across the pair of flanges; a pressure ring that holds the side wall portion and the edge portion between the pressure ring and the flange, The compression ring is an elastic coupling formed so that the front end portion of the contact surface that contacts the side wall portion, closest to the flange, is located in the portion that contacts radially outward from the radial center of the side wall portion.

7. 7. The elastic coupling according to claim 6, wherein the bead core is positioned so that the front end portion radially overlaps at least a portion of the bead core when the side wall portion and the edge portion are sandwiched between the flange and the compression ring.

8. 7. The elastic shaft coupling according to claim 6, wherein the contact surface is formed in a radially convex shape, and the tip end portion is an apex of the convex shape.

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