Cylindrical elastic connecting device for axle beam

Abstract

[Problem] To provide a cylindrical elastic connecting device for an axle beam, said connecting device having a novel structure in which a cleaning liquid or other liquid does not readily remain in an insertion portion of an attachment bolt in an inner axle member, and an adverse effect on performance resulting from the remaining liquid can be prevented. [Solution] A cylindrical elastic connecting device 10 for an axle beam in which an inner axle member 12 and a pair of outer divided bodies 14a, 14b are elastically connected to each other by a main rubber elastic body 16, and a truck frame 70 and an axle beam 80 are elastically connected to each other, wherein: a stopper member 30 is attached to the inner axle member 12, the stopper member 30 limiting, by contact with a housing part 82, the relative displacement amount between the inner axle member 12 and the pair of outer divided bodies 14a, 14b toward either side in the longitudinal direction of a railway vehicle; a bolt insertion hole 24 is formed through the inner axle member 12 in a direction perpendicular to the axle; and the stopper member 30 and the inner axle member 12 are fixed to each other by an attachment bolt 48 inserted into the bolt insertion hole 24.

Description

Cylindrical Elastic Coupling Device for Axle Bolsters

[0001] The present invention relates to a cylindrical elastic coupling device for an axle bolster that elastically couples one end of an axle bolster to a bogie frame of a railway vehicle.

[0002] Conventionally, in railway vehicles, a structure has been generally adopted in which an axle bolster extends from an axle box portion that supports an axle in the longitudinal direction of the vehicle, and an end portion of the axle bolster is elastically coupled to a bogie frame by a cylindrical elastic coupling device. As disclosed in Japanese Patent No. 7189809 (Patent Document 1) and the like, this cylindrical elastic coupling device for an axle bolster has a structure in which a pair of outer split bodies (outer portions) extending in the circumferential direction are disposed on the outer peripheral side of an inner shaft member (central shaft), and the inner shaft member and the pair of outer split bodies are elastically coupled to each other by a main body rubber elastic body (elastic portion). Then, both axial ends of the inner shaft member are attached to the bogie frame, and the outer split body is attached to a cylindrical housing portion provided at one end of the axle bolster, so that the axle bolster is elastically supported by the bogie frame via the cylindrical elastic coupling device for the axle bolster.

[0003] Japanese Patent No. 71898XXX

[0004] By the way, in the cylindrical elastic coupling device for an axle bolster, a stopper member may be provided to limit the relative displacement amount between the inner shaft member and the pair of outer split bodies in a specific radial direction where a large load input is expected. That is, in the cylindrical elastic coupling device for an axle bolster, since a large load during deceleration is input in the radial direction corresponding to the longitudinal direction of the vehicle, in Patent Document 1, a stopper member (elastic stopper) that protrudes from the inner shaft member toward the outer periphery in the radial direction is provided. Then, when the inner shaft member and the housing portion abut against each other via the stopper member, the relative displacement amount between the inner shaft member and the outer split body is limited in a specific radial direction, and the durability of the main body rubber elastic body and the braking performance of the target railway vehicle are realized.

[0005] Further, the stopper member of Patent Document 1 has a through mounting hole formed therein, and a bolt inserted through the mounting hole is fixed to the inner shaft member by being screwed into a screw hole that opens on the outer peripheral surface of the inner shaft member.

[0006] However, in the mounting structure for the stopper member shown in Patent Document 1, since a bottomed mounting hole is formed in the inner shaft member, there is a problem that cleaning fluid such as water tends to remain in the mounting hole when cleaning the inner shaft member during the manufacturing process of a cylindrical elastic coupling device for shafts and beams. As a result, rust may easily form on the threaded portion of the bolt, or the lubricating effect of the cleaning fluid may be exerted, which could affect the fixing force of the stopper member.

[0007] The problem to be solved by the present invention is to provide a novel cylindrical elastic coupling device for shafts and beams that prevents liquids such as cleaning solutions from remaining in the insertion portion of the mounting bolt in the inner shaft member, thereby preventing adverse effects on performance due to liquid residue.

[0008] The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is illustrative and can be combined with others as appropriate. Furthermore, the multiple components described in each embodiment can be recognized and adopted as independently as possible, and can be combined with any component described in another embodiment as appropriate. Thus, the present invention is not limited to the embodiments described below, and various other embodiments can be realized.

[0009] The first embodiment is a cylindrical elastic coupling device for an axle beam in which a pair of outer segments facing each other perpendicular to the axis are arranged on the outer circumference of an inner axle member, and the inner axle member and the pair of outer segments are elastically connected to each other by a main rubber elastic body, and the inner axle member is attached to the bogie frame of a railway vehicle, and the pair of outer segments are attached to a cylindrical housing portion provided at one end of the axle beam, thereby elastically connecting the bogie frame and the axle beam, wherein a stopper member is attached to the inner axle member which limits the relative displacement between the inner axle member and the pair of outer segments in either the front-rear direction of the railway vehicle by contact with the housing portion, and a bolt insertion hole is formed in the inner axle member which penetrates in the direction perpendicular to the axis, and the stopper member and the inner axle member are fixed to each other by a mounting bolt inserted through the bolt insertion hole.

[0010] In the cylindrical elastic coupling device for shafts and beams constructed according to this embodiment, the mounting bolt that is screwed into the stopper member is inserted through a bolt insertion hole that penetrates the inner shaft member. Therefore, compared to the case where the mounting bolt is screwed into a bottomed threaded hole formed in the inner shaft member, liquids such as cleaning fluid used to clean the inner shaft member are less likely to remain in the mounting bolt insertion portion of the inner shaft member, thus preventing adverse effects on durability and fixing strength caused by residual liquid.

[0011] The second embodiment is a cylindrical elastic coupling device for an axial beam as described in the first embodiment, wherein the tip surface of the stopper member that contacts the housing portion is a smoothly continuous stopper contact surface.

[0012] According to the cylindrical elastic coupling device for shafts and beams constructed in accordance with this embodiment, the mounting bolt inserted through the bolt insertion hole of the inner shaft member is screwed into the stopper member from the base end side, making it easy to create a smooth and continuous stopper contact surface on the tip surface of the stopper member. Because the tip surface of the stopper member is a smooth stopper contact surface without holes or indentations, stress is distributed when the stopper member contacts the housing, thereby improving durability.

[0013] The third embodiment is a cylindrical elastic coupling device for an axial beam as described in the first embodiment, wherein the stopper member has an open tip hole formed on the tip surface that abuts against the housing portion.

[0014] According to the cylindrical elastic coupling device for shafts and beams constructed in accordance with this embodiment, the stopping action caused by the contact between the stopper member and the housing can be adjusted by the opening at the tip surface of the stopper member. Therefore, the impact noise and shock sensation that occur when the stopper member and the housing come into contact can be reduced.

[0015] The fourth aspect is a cylindrical elastic coupling device for a shaft beam as described in the third aspect, wherein the bolt insertion hole of the inner shaft member is a threaded portion in which at least a part of it has threads formed on its inner circumferential surface, and the mounting bolt, which is inserted from the tip opening hole and passes through the stopper member, is screwed into the threaded portion of the bolt insertion hole.

[0016] According to the cylindrical elastic coupling device for shafts and beams constructed in accordance with this embodiment, the stopper member and the inner shaft member can be fixed together without the need for a nut by screwing a mounting bolt that passes through the stopper member from the tip side into the bolt insertion hole of the inner shaft member. Furthermore, since the direction in which the stopper member is superimposed on the inner shaft member and the direction in which the mounting bolt is inserted into the bolt insertion hole are the same, the installation of the stopper member can be easily performed from one direction. In addition, because the bolt insertion hole is a through hole, for example, when forming the threads of the screw portion on the inner circumferential surface of the bolt insertion hole by cutting, it is easier to prevent cutting chips from accumulating inside the bolt insertion hole compared to the case of a bottomed hole, and it is possible to prevent defects in thread formation due to the retention of cutting chips. Furthermore, because the bolt insertion hole is a through hole, defects such as cutting defects in the screw portion can be easily visually confirmed.

[0017] The fifth embodiment is a cylindrical elastic coupling device for an axial beam as described in the fourth embodiment, wherein the threaded portion is provided along the entire length of the bolt insertion hole in the penetrating direction.

[0018] According to the cylindrical elastic coupling device for shafts and beams constructed in accordance with this embodiment, the mounting bolt is screwed in along the entire length of the bolt insertion hole, which allows for a large degree of freedom in adjusting the fixing force between the stopper member and the inner shaft member by the mounting bolt.

[0019] The sixth embodiment is a cylindrical elastic coupling device for an axial beam as described in the fourth or fifth embodiment, wherein the threaded portion is partially provided in the direction of passing through the bolt insertion hole.

[0020] According to the cylindrical elastic coupling device for axial beams constructed in accordance with this embodiment, the threaded portion is partially provided in the bolt insertion hole, which prevents the threading length of the mounting bolt from becoming excessively long, thus facilitating the bolt fixing work.

[0021] The seventh aspect is a cylindrical elastic coupling device for an axial beam as described in the third aspect, wherein the entire bolt insertion hole is a non-threaded portion, and the mounting bolt, which is inserted from the open tip hole and passes through the stopper member, passes through the bolt insertion hole and is screwed into a nut located on the radially opposite side of the stopper member.

[0022] According to the cylindrical elastic coupling device for shafts and beams constructed in accordance with this embodiment, for example, the stopper member and the inner shaft member can be bolted together by rotating and screwing a nut onto a mounting bolt inserted into the inner shaft member, without screwing the mounting bolt into the inner shaft member.

[0023] The eighth aspect is a cylindrical elastic coupling device for an axial beam described in any one of the first to seventh aspects, wherein the entire bolt insertion hole is a non-threaded portion, and the mounting bolt inserted through the bolt insertion hole from the radially opposite side of the stopper member is screwed into a threaded hole provided in the stopper member.

[0024] According to the cylindrical elastic coupling device for shafts and beams constructed in accordance with this embodiment, the stopper member functions as a nut, eliminating the need to prepare a separate nut and thus reducing the number of parts. Furthermore, since the stopper member is screwed onto a mounting bolt inserted through the bolt insertion hole of the inner shaft member from the opposite side of the stopper member, it becomes possible, for example, to create a structure in which the tip surface of the stopper member is smooth and continuous without a hole.

[0025] The ninth aspect is a cylindrical elastic coupling device for an axial beam described in any one of the first to eighth aspects, wherein the inner axial member is provided with a bolt seat surface on the radially opposite side of the stopper member, which is a plane that extends perpendicular to the through-direction of the bolt insertion hole, and onto which the head of the mounting bolt is superimposed.

[0026] According to the cylindrical elastic coupling device for shafts and beams constructed in accordance with this embodiment, the inner shaft member is provided with a bolt seating surface that extends perpendicularly to the bolt insertion hole, thereby preventing rattling of the mounting bolt, ensuring stable fixing of the stopper member to the inner shaft member, and preventing abnormal noise caused by contact between the mounting bolt and the inner shaft member.

[0027] The tenth aspect is a cylindrical elastic coupling device for an axial beam described in any one of the first to ninth aspects, wherein the overlapping surface of the stopper member on the inner shaft member is a stopper seat surface formed by a plane that extends perpendicularly to the central axis of the mounting bolt.

[0028] According to the cylindrical elastic coupling device for shafts and beams with a structure conforming to this embodiment, the overlapping surface of the stopper member with the inner shaft member can be made flat, which facilitates the manufacture of the stopper member.

[0029] According to the combination of the ninth and tenth embodiments, the openings on both sides of the bolt insertion hole in the inner shaft member are both planes that extend perpendicular to the bolt insertion hole. This makes it difficult for force components other than those in the tightening direction (axial direction of the mounting bolt) to be generated when the mounting bolt is screwed into the stopper member and tightened, thus efficiently obtaining fixing force. Furthermore, tilted mounting of the stopper member to the inner shaft member is also prevented.

[0030] The eleventh aspect is a cylindrical elastic coupling device for an axial beam described in any one of the first to tenth aspects, wherein the stopper member has a rigid base that is bolted to the inner axial member, and the stopper member has an elastic portion fixed to the tip side of the base and forming the tip surface of the stopper member.

[0031] According to the cylindrical elastic coupling device for shafts and beams constructed in accordance with this embodiment, the stopper member has a rigid base, allowing the stopper member to be fixed stably to the inner shaft member with sufficient strength. Furthermore, since the tip portion of the stopper member is composed of an elastic part, the stopper action exerted by the contact between the stopper member and the housing can be adjusted, and the noise generated during contact can also be reduced.

[0032] The twelfth aspect is a cylindrical elastic coupling device for an axial beam described in the eleventh aspect, wherein the elastic part is made of a material harder than the main rubber elastic body.

[0033] According to the cylindrical elastic coupling device for shafts and beams constructed in accordance with this embodiment, the elastic part is made of a harder material than the main rubber elastic body, thereby ensuring durability in the elastic part of the stopper member that is subjected to a large stopper load. Furthermore, because the elastic part is made of a harder material than the main rubber elastic body, the relative displacement between the inner shaft member and a pair of outer segmented bodies can be effectively limited.

[0034] The thirteenth aspect is a cylindrical elastic coupling device for an axial beam described in the eleventh or twelfth aspect, wherein the elastic portion of the stopper member is a laminated structure comprising a tip elastic body constituting the tip surface of the stopper member, an intermediate elastic body fixed to the tip side of the base, and a rigid intermediate restraining member disposed between the tip elastic body and the intermediate elastic body.

[0035] According to the cylindrical elastic coupling device for axial beams with a structure conforming to this embodiment, when the tip surface of the stopper member is pressed against the housing and a stopper load is applied to the stopper member, the total thickness of the tip elastic body and the intermediate elastic body can be increased while adjusting the spring characteristics of the entire stopper member, compared to a stopper member with a single layer of elastic material, thereby improving the durability of the elastic material.

[0036] The fourteenth aspect is a cylindrical elastic coupling device for an axial beam described in the thirteenth aspect, wherein the tip elastic body and the intermediate elastic body are made of the same elastic material.

[0037] According to the cylindrical elastic coupling device for axial beams with a structure conforming to this embodiment, it becomes easier to form the tip elastic body and the intermediate elastic body simultaneously.

[0038] The fifteenth embodiment is a cylindrical elastic coupling device for an axial beam described in any one of the first to fourteenth embodiments, wherein one of the pair of outer divisions has a radially penetrating window portion, and the stopper member is exposed through the window portion.

[0039] According to the cylindrical elastic coupling device for shafts and beams constructed in accordance with this embodiment, when mounted on a railway vehicle, the stopper member contacts the housing through the window, thereby exhibiting a stopper action that limits the relative displacement between the inner shaft member and the pair of outer split parts. Furthermore, the installation of the stopper member to the inner shaft member can be performed through the window, thus facilitating the installation process.

[0040] The sixteenth aspect is a cylindrical elastic coupling device for an axial beam as described in the fifteenth aspect, wherein the other of the pair of outer segments has a radially penetrating opening, and the pair of outer segments are all the same shape.

[0041] According to the cylindrical elastic coupling device for shaft collars having a structure according to this aspect, a set of outer split members can be configured with common parts. Further, for example, while overlapping the stopper member on the inner shaft member through the window portion of one outer split member, the mounting bolt is inserted into the bolt insertion hole of the inner shaft member through the window portion of the other outer split member, and the mounting bolt can be screwed into the stopper member, improving the workability of attaching the stopper member.

[0042] The seventeenth aspect is the cylindrical elastic coupling device for shaft collars described in any one of the first to third, seventh to sixteenth aspects, wherein the inner peripheral surface of the bolt insertion hole is a smoothly continuous cylindrical surface.

[0043] According to the cylindrical elastic coupling device for shaft collars having a structure according to this aspect, the inner peripheral surface of the bolt insertion hole is a smoothly continuous cylindrical surface without irregularities such as threads, and a liquid such as a cleaning liquid that has entered the bolt insertion hole is efficiently discharged without being held by the irregularities of the inner peripheral surface of the bolt insertion hole. Therefore, problems such as corrosion caused by the remaining liquid in the bolt insertion hole are more advantageously prevented.

[0044] According to the present invention, in the cylindrical elastic coupling device for shaft collars, it is difficult for a liquid such as a cleaning liquid to remain in the insertion portion of the mounting bolt in the inner shaft member, and an adverse effect on performance due to the remaining liquid can be prevented.

[0045] A perspective view showing a rubber bushing for a shaft beam as the first embodiment of the present invention. A plan view of the rubber bushing for a shaft beam shown in Figure 1. A left side view of the rubber bushing for a shaft beam shown in Figure 1. A cross-sectional view of the rubber bushing for a shaft beam shown in Figure 1, corresponding to the IV-IV section in Figure 3. A cross-sectional view of the rubber bushing for a shaft beam shown in Figure 1, corresponding to the V-V section in Figure 3. A cross-sectional view of the rubber bushing for a shaft beam shown in Figure 1, corresponding to the VI-VI section in Figure 4. A diagram showing the state in which the rubber bushing for a shaft beam shown in Figure 1 is mounted on a railway vehicle. A cross-sectional view showing a rubber bushing for a shaft beam as the second embodiment of the present invention, corresponding to the VIII-VIII section in Figure 9. A cross-sectional view of the rubber bushing for a shaft beam shown in Figure 8. A cross-sectional view of the bushing, corresponding to the IX-IX section in Figure 8. A cross-sectional view showing a rubber bushing for a shaft beam as a third embodiment of the present invention, corresponding to the X-X section in Figure 11. A cross-sectional view of the rubber bushing for a shaft beam shown in Figure 10, corresponding to the XI-XI section in Figure 10. A cross-sectional view showing a rubber bushing for a shaft beam as a fourth embodiment of the present invention, corresponding to the XII-XII section in Figure 13. A cross-sectional view of the rubber bushing for a shaft beam shown in Figure 12, corresponding to the XIII-XIII section in Figure 12. A cross-sectional view showing a rubber bushing for a shaft beam as another embodiment of the present invention. A cross-sectional view showing a rubber bushing for a shaft beam as yet another embodiment of the present invention.

[0046] Embodiments of the present invention will be described below with reference to the drawings.

[0047] Figures 1 to 6 show a rubber bushing 10 for a shaft beam as a cylindrical elastic coupling device for a shaft beam, as a first embodiment of the present invention. The rubber bushing 10 for a shaft beam has a structure in which an inner shaft member 12 and front and rear outer splits 14a and 14b, which are arranged opposite each other on the outer circumference of the inner shaft member and the outer splits 14a and 14b, are elastically connected to each other by a main rubber elastic body 16. In the following description, as a general rule, the vertical direction refers to the vertical direction in Figure 3, the front and rear direction refers to the left and right direction in Figure 3, and the left and right direction refers to the left and right direction in Figure 2.

[0048] The inner shaft member 12 is generally rod-shaped and linearly extends in the left-right direction as a whole. For example, it is a high-rigidity member formed of a metal such as iron or an aluminum alloy. The inner shaft member 12 has a structure integrally formed with a cylindrical central shaft main body 18, a pair of flange-shaped inner flange portions 20, 20 that project outward from the outer periphery at both axial ends of the central shaft main body 18, and a pair of mounting portions 22, 22 that project further axially outward than the inner flange portions 20, 20.

[0049] The central shaft main body 18 linearly extends in the left-right direction with a substantially constant circular cross-section. A bolt insertion hole 24 penetrating in the radial direction is formed in the central shaft main body 18 of the inner shaft member 12. The bolt insertion hole 24 is a through-hole linearly extending with a substantially circular cross-section, and is provided so as to penetrate in the front-rear direction at the central portion in the axial direction of the central shaft main body 18. The inner peripheral surface of the bolt insertion hole 24 is a smooth and continuous cylindrical surface without irregularities such as threads, and the bolt insertion hole 24 is a non-threaded portion over its entire length. The bolt insertion hole 24 has a larger diameter than the shaft portion 50 of a mounting bolt 48 described later.

[0050] In the inner shaft member 12 of the present embodiment in which the bolt insertion hole 24 penetrating the central shaft main body 18 is formed, for example, when the inner shaft member 12 is washed with a cleaning liquid such as water and then air is blown to remove the cleaning liquid, the cleaning liquid is less likely to remain in the bolt insertion hole 24 compared to an inner shaft member in which a bottomed screw hole is formed. Therefore, it is possible to prevent the generation of rust due to the remaining cleaning liquid. Further, since the inner peripheral surface of the bolt insertion hole 24 is a cylindrical surface without threads, the cleaning liquid is not retained between the pitches of the threads, and it is easier to prevent the remaining of the cleaning liquid.

[0051] A bolt seating surface 26 composed of a plane extending orthogonally to the central axis direction (front-rear direction) of the bolt insertion hole 24 is provided at the opening peripheral edge portion on the rear side of the bolt insertion hole 24 in the central shaft main body 18. The bolt seating surface 26 is larger than the head 52 of the mounting bolt 48 described later, and it is possible to overlap the entire head 52 of the mounting bolt 48 inserted into the bolt insertion hole 24 in a contacting state with the bolt seating surface 26.

[0052] The inner flange portions 20, 20 are annular plate-shaped, with the axial outer surface widening in a direction approximately perpendicular to the axis, and the inner circumference portion of the axial inner surface being tapered, with the inner circumference portion gradually becoming thinner towards the outer circumference, and the outer circumference portion widening to a substantially constant thickness.

[0053] As shown in Figures 1 to 3, the mounting portion 22 has a roughly polygonal prism shape and has bolt holes 28 that pass through it linearly in the vertical direction. The mounting portion 22 is then fixed to the trolley frame 70, which will be described later, by fastening bolts (not shown) that are inserted through the bolt holes 28.

[0054] Furthermore, the shape of the inner shaft member 12 is not limited by the specific description of the embodiment, and the specific shapes of each part constituting the inner shaft member 12 (the central shaft body 18, inner flange portion 20, mounting portion 22, and bolt hole 28 in this embodiment) are not particularly limited.

[0055] As shown in Figures 4 and 6, a stopper member 30 is attached to the central shaft body 18 of the inner shaft member 12. The stopper member 30 is approximately rectangular in shape when viewed in the front-rear direction. The stopper member 30 comprises a rigid base portion 32 fixed to the inner shaft member 12 and an elastic portion 34 provided on the tip side opposite to the inner shaft member 12 relative to the base portion 32.

[0056] The base portion 32 is roughly rectangular in shape and is a highly rigid member made of metal such as iron or aluminum alloy. The tip surface of the base portion 32 that overlaps with the elastic portion 34 is a curved surface that curves in the circumferential direction of the inner shaft member 12. Furthermore, the base end surface of the base portion 32 that overlaps with the central shaft body 18 of the inner shaft member 12 is an inner-side corresponding surface 36 which is a curved surface corresponding to the outer circumferential surface of the inner shaft member 12.

[0057] A screw hole 38 is formed in the base portion 32. The screw hole 38 is a bottomed circular concave shape with screw threads formed on its inner circumferential surface. The screw hole 38 opens on the inner corresponding surface 36 (rear surface) of the base portion 32, but does not open on the tip surface (front surface). Because the screw hole 38 is formed in the base portion 32, it has a female screw structure into which a mounting bolt 48, which will be described later, is screwed.

[0058] The elastic section 34 has a laminated structure in which a rigid intermediate restraining member 44 is positioned between a tip elastic body 40 and an intermediate elastic body 42, both of which are made of elastic material. The entire elastic section 34 is made of a material that is harder than the main rubber elastic body 16. In particular, both the tip elastic body 40 and the intermediate elastic body 42 are made of an elastic material that is harder than the main rubber elastic body 16.

[0059] The tip elastic body 40 is a thin rubber layer that is superimposed on and fixed to the tip surface of the intermediate restraint member 44, and constitutes the tip surface of the stopper member 30. The tip elastic body 40 is made of a rubber material that is harder than the main rubber elastic body 16. The tip surface of the tip elastic body 40, which is the tip surface of the stopper member 30, is a smooth, continuous stopper contact surface 46 without holes. The tip elastic body 40 may also be made of a resin elastomer that exhibits rubber-like elasticity.

[0060] The intermediate elastic body 42 is a thin rubber layer that is superimposed on and fixed to the tip surface of the base portion 32. The intermediate elastic body 42 is made of a rubber material that is harder than the main rubber elastic body 16. In this embodiment, the tip elastic body 40 and the intermediate elastic body 42 are made of the same elastic material, and manufacturing is facilitated by making it easier to mold the tip elastic body 40 and the intermediate elastic body 42 simultaneously. The intermediate elastic body 42 may also be made of a resin elastomer that exhibits rubber-like elasticity.

[0061] The intermediate restraint member 44 is plate-shaped and curved in correspondence with the tip surface of the base 32, and is positioned at a distance from the tip side of the base 32. An intermediate elastic body 42 is positioned between the opposing surfaces of the base 32 and the intermediate restraint member 44, and the base 32 and the intermediate restraint member 44 are interconnected by the intermediate elastic body 42. The tip surface of the intermediate restraint member 44 is substantially covered by a tip elastic body 40.

[0062] The stopper member 30, having the structure described above, is fixed to the inner shaft member 12 by a mounting bolt 48. The mounting bolt 48 comprises a shaft portion 50 with threads formed on its outer circumference and a head portion 52 integrally formed at the rear end of the shaft portion 50. The outer diameter of the shaft portion 50 is smaller than the inner diameter of the bolt insertion hole 24 of the inner shaft member 12, allowing it to be inserted into the bolt insertion hole 24 without being screwed in. The head portion 52 is cylindrical and has a larger diameter than the shaft portion 50. In this embodiment, the mounting bolt 48 has a hexagonal cross-section recess formed on the rear surface of the head portion 52, and is a socket head cap bolt that can be rotated by inserting a hexagonal wrench into the recess. Note that the mounting bolt is not limited to a socket head cap bolt, and may be a hexagonal bolt with a hexagonal columnar head, etc.

[0063] The shaft portion 50 of the mounting bolt 48 is inserted into the bolt insertion hole 24 of the inner shaft member 12 from the rear, which is opposite to the mounting side of the stopper member 30, and passes through the bolt insertion hole 24. The shaft portion 50 of the mounting bolt 48 is inserted with a gap in the bolt insertion hole 24. The head portion 52 of the mounting bolt 48 is superimposed on the bolt seating surface 26 provided on the outer circumferential surface of the inner shaft member 12. Since the bolt seating surface 26 widens perpendicular to the central axis direction of the bolt insertion hole 24, substantially the entire front end surface of the head portion 52 of the shaft portion 50 inserted into the bolt insertion hole 24 is in contact with and superimposed on the bolt seating surface 26.

[0064] The shaft portion 50 of the mounting bolt 48 protrudes forward from the front opening of the bolt insertion hole 24. The tip of the shaft portion 50 protruding from the bolt insertion hole 24 is screwed into a threaded hole 38 formed in the base portion 32 of the stopper member 30. As a result, the stopper member 30 is bolted to the inner shaft member 12 with its inner corresponding surface 36 overlapping the outer circumferential surface of the central shaft body 18 of the inner shaft member 12, and protrudes forward from the central shaft body 18 of the inner shaft member 12.

[0065] In this embodiment, the outer circumferential surface of the central shaft body 18 in the inner shaft member 12 is a cylindrical surface that curves in the circumferential direction, and the overlapping surface (base end surface) of the base portion 32 of the stopper member 30 with the central shaft body 18 is an inner-side corresponding surface 36 that curves in the circumferential direction with a shape corresponding to the outer circumferential surface of the central shaft body 18. The outer circumferential surface of the central shaft body 18, which is the rotation limiting surface on the inner shaft member 12 side, and the inner-side corresponding surface 36, which is the rotation limiting surface on the stopper member 30 side, are overlapped with each other, thereby forming a rotation limiting mechanism that limits the relative amount of rotation of the stopper member 30 around the mounting bolt 48 with respect to the inner shaft member 12. This rotation limiting mechanism fixes the stopper member 30 to the inner shaft member 12 in an appropriate orientation around the central axis of the mounting bolt 48.

[0066] It is desirable that the stopper member 30 be positioned to some extent before screwing in the mounting bolt 48, so that the orientation of the mounting bolt 48 around the central axis is appropriate with respect to the inner shaft member 12. For example, by pressing the stopper member 30 against the central shaft body 18 of the inner shaft member 12 in the appropriate orientation while tightening the mounting bolt 48, it is possible to prevent the stopper member 30 from rotating integrally with the mounting bolt 48, and to easily screw the mounting bolt 48 into the screw hole 38. In this embodiment, the rear surface of the central shaft body 18 onto which the head 52 of the mounting bolt 48 is superimposed is a bolt seat surface 26 composed of a plane that extends in a direction perpendicular to the mounting bolt 48, and relative rotation of the head 52 with respect to the central shaft body 18 is permitted until the mounting bolt 48 is fully screwed into the stopper member 30. Therefore, the mounting bolt 48 can be screwed all the way into the screw hole 38 of the stopper member 30 while the stopper member 30 is positioned and held relative to the central shaft body 18 by the rotation limiting mechanism.

[0067] Outer segments 14a and 14b are positioned on both the front and rear sides of the inner shaft member 12 to which the stopper member 30 is attached. Both outer segments 14a and 14b have a curved plate shape that extends circumferentially for a length of less than half a circumference. Outer flanges 54, 54 that protrude outward are integrally formed at both axial ends of the outer segments 14a and 14b. The outer flanges 54 protrude outward while inclined axially outward, and are positioned opposite the inner flange 20 at a predetermined distance axially inward. The outer segments 14a and 14b have approximately the same circumferential length.

[0068] One of the outer sections 14a has a window portion 56 formed therein. The window portion 56 penetrates the central part of the outer section 14a in the circumferential and axial directions in the front-to-back direction and has a roughly square opening shape. In the axial beam rubber bush 10, the window portion 56 is larger than the front end surface of the stopper member 30 in the front-to-back projection, and is sized so that the entire front end surface of the stopper member 30 can be exposed through the window portion 56.

[0069] An opening 58 is formed in the other outer segment 14b. The opening 58 penetrates the central part of the outer segment 14b in the front-to-back direction in both the circumferential and axial directions, and has a roughly square shape. In the axial beam rubber bush 10, the opening 58 is approximately the same shape and size as the window portion 56 of the other outer segment 14a. Thus, in this embodiment, one outer segment 14a and the other outer segment 14b have the same shape as each other, enabling the commonality of parts.

[0070] The outer segments 14a and 14b are positioned separately on the outer circumference of the central shaft body 18 of the inner shaft member 12, and the inner shaft member 12 and the outer segments 14a and 14b are elastically connected to each other by the main rubber elastic body 16. The outer segments 14a and 14b are positioned radially opposite each other with the central shaft body 18 in between, and their circumferential ends are separated from each other.

[0071] The main rubber elastic body 16 has a generally thick, substantially cylindrical shape, and rubber flanges 60, 60 projecting outward are integrally formed at both axial ends. The inner circumferential surface of the cylindrical central axial portion of the main rubber elastic body 16 is vulcanized and bonded to the outer circumferential surface of the central shaft body 18 of the inner shaft member 12, while the outer circumferential surface is vulcanized and bonded to the inner circumferential surfaces of the outer segmented bodies 14a, 14b. Each rubber flange 60 is positioned between the opposing surfaces of the inner flange 20 of the inner shaft member 12 and the outer flanges 54, 54 of the outer segmented bodies 14a, 14b, and is vulcanized and bonded to the inner flange 20 and outer flanges 54, 54. In this embodiment, the main rubber elastic body 16 is formed as an integrally vulcanized molded product comprising the inner shaft member 12 and the outer segmented bodies 14a, 14b.

[0072] A pocket portion 62 is formed in the main rubber elastic body 16. The pocket portion 62 is concave, opening to the outer circumferential surface of the main rubber elastic body 16, and is formed in the axial central portion of the main rubber elastic body 16. In this embodiment, a pair of pocket portions 62a and 62b, which are substantially the same shape, are formed to open to both the front and rear sides of the main rubber elastic body 16. The outer circumferential surface of the main rubber elastic body 16 is fixed to the outer split bodies 14a and 14b around the openings of the pocket portions 62a and 62b. The window portion 56 of the outer split body 14a is positioned to coincide with the opening of the front pocket portion 62a, and the pocket portion 62a is open to the outer circumferential surface through the window portion 56. Similarly, the opening 58 of the outer split body 14b is positioned to coincide with the opening of the rear pocket portion 62b, and the pocket portion 62b is open to the outer circumferential surface through the opening 58.

[0073] The stopper member 30 attached to the inner shaft member 12 protrudes into the front pocket portion 62a. The stopper member 30 is positioned in the central part of the pocket portion 62a, and at least the elastic portion 34 is separated from the inner wall surface of the pocket portion 62a. The protruding tip surface of the stopper member 30 located inside the pocket portion 62a is exposed through the opening and window portion 56 of the pocket portion 62a.

[0074] The mounting bolt 48 that secures the stopper member 30 to the inner shaft member 12 has its head 52 located within the rear pocket portion 62b. The head 52 of the mounting bolt 48 is exposed towards the rear through the opening and opening 58 of the pocket portion 62b. By rotating the mounting bolt 48 with a hexagonal wrench (not shown) inserted into the pocket portion 62b through the opening 58, the mounting bolt 48 can be tightened or loosened in relation to the screw hole 38 of the stopper member 30.

[0075] As shown in Figures 2, 5, and 6, the main rubber elastic body 16 is exposed between the outer segments 14a and 14b in the circumferential direction, and a free surface is provided in the exposed portion that is not constrained by metal fittings or the like. An annular groove 64 is opened on the outer circumferential surface of the main rubber elastic body 16 that is exposed between the outer segments 14a and 14b in the circumferential direction. The annular groove 64 is composed of a transverse groove that extends axially along the circumferential ends of the outer segments 14a and 14b, and a circumferential groove that extends circumferentially along the base end of the rubber flange portion 60 of the main rubber elastic body 16, and extends continuously in a substantially rectangular annular shape in the exposed portion of the main rubber elastic body 16. As shown in Figures 5 and 6, the region of the main rubber elastic body 16 enclosed by the annular groove 64 is a protruding portion 66 that projects outward.

[0076] As shown in Figure 7, the axle beam rubber bush 10, with this structure, is attached to the bogie 68 of a railway vehicle. The bogie 68 comprises a bogie frame 70 and wheels 72. The axle box portion 76 that supports the axle 74 of the wheel 72 is elastically connected to the bogie frame 70 by an axle spring 78, and the axle beam 80 extends forward from the axle box portion 76. The housing portion 82 provided at the extended end of the axle beam 80 is connected to the bogie frame 70 by the axle beam rubber bush 10. Figure 7 shows the longitudinal and vertical directions of the railway vehicle. As can be seen from Figure 7, the longitudinal and vertical directions of the axle beam rubber bush 10 are approximately the same as the longitudinal and vertical directions of the railway vehicle.

[0077] In Figure 7, the front portion of the bogie 68 is omitted, but on both sides of the bogie frame 70 extending in the vehicle's longitudinal direction, axle box portions 76 are provided, and wheel support structures supporting wheels 72 are provided on each side. The front of the bogie 68 is provided with a wheel support structure that is substantially symmetrical to that in the vehicle's longitudinal direction as shown in Figure 7. In this embodiment, the right side in Figure 7 is considered the front of the vehicle, but the left side in Figure 7 may also be the front of the vehicle. In that case, the stopper member 30 of the axle beam rubber bush 10 protrudes from the inner axle member 12 toward the rear of the vehicle.

[0078] More specifically, the roughly cylindrical housing portion 82 is constructed by fixing together roughly semi-cylindrical semi-tubular members 84a and 84b that face each other in the front-rear direction of the vehicle. The axle beam rubber bush 10 is fitted into the housing portion 82 in an inserted state, with the outer divided parts 14a and 14b sandwiched between the opposing semi-tubular members 84a and 84b.

[0079] The outer splits 14a and 14b are positioned such that the orientation of the axle beam rubber bushings 10 is set so that their opposing directions are approximately the front and rear of the vehicle, and the semi-cylindrical members 84a and 84b are superimposed on the outer splits 14a and 14b from the outside in the opposing direction. In this way, because the housing portion 82 is a split structure composed of a front and rear pair of semi-cylindrical members 84a and 84b, the outer splits 14a and 14b can be attached to the housing portion 82 with simple work. Furthermore, because the circumferential ends of the semi-cylindrical members 84a and 84b are positioned between the circumferential ends of the outer splits 14a and 14b, it is possible to prevent the edges of the circumferential ends of the semi-cylindrical members 84a and 84b from contacting the outer circumferential surfaces of the outer splits 14a and 14b, thereby avoiding damage to the outer splits 14a and 14b due to galling.

[0080] The housing portion 82 is attached to the outer circumferential surfaces of the outer segments 14a and 14b, so that the window portion 56 of the outer segment 14a is covered by the semi-cylindrical member 84a of the housing portion 82. The semi-cylindrical member 84a of the housing portion 82 and the stopper member 30 attached to the inner shaft member 12 face each other in the front-rear direction at a predetermined distance apart. The opening 58 of the outer segment 14b is covered by the semi-cylindrical member 84b of the housing portion 82.

[0081] On the other hand, the inner shaft member 12 of the shaft beam rubber bush 10 is attached to the bogie frame 70 by fastening bolts (not shown) that are inserted through bolt holes 28, with mounting portions 22 provided at both ends in the axial direction.

[0082] In this way, the inner axle member 12 of the axle beam rubber bush 10 is attached to the bogie frame 70, and the outer divided parts 14a and 14b are attached to the axle beam 80 on the axle box portion 76 side, so that the axle box portion 76 is elastically connected to the bogie frame 70 via the axle spring 78 and the axle beam rubber bush 10. Then, vertical vibrations input to the bogie frame 70 due to passengers getting on and off are absorbed by the axle spring 78. Furthermore, when the axle box portion 76 is displaced vertically with deformation of the axle spring 78, the oscillation of the axle beam 80 around the inner axle member 12 is permitted by the elastic deformation of the main rubber elastic body 16.

[0083] Incidentally, the bogie frame 70 is equipped with a brake device 86, which applies a brake shoe 88 to the outer surface of the wheel 72 from either the front or rear using hydraulic pressure or the like, thereby braking the rotation of the wheel 72. Thus, in the bogie 68 of this embodiment, the brake device 86 is a single-sided brake.

[0084] For example, when the brake shoe 88 is pressed against the wheel 72 from the front of the vehicle, a rearward force acts on the axle beam 80, causing the axle beam 80 to be displaced rearward, and the housing portion 82 provided on the axle beam 80 to be displaced rearward relative to the inner axle member 12. Then, the stopper member 30 fixed to the inner axle member 12 comes into contact with the semi-cylindrical member 84a of the housing portion 82 that covers the window portion 56 of the outer split body 14a, thereby limiting the amount of forward relative displacement of the inner axle member 12 with respect to the outer split bodies 14a and 14b fixed to the housing portion 82. This prevents excessive deformation of the main rubber elastic body 16 that connects the inner axle member 12 and the outer split bodies 14a and 14b, thereby improving durability.

[0085] Since the tip portion of the stopper member 30, including the contact surface with the housing portion 82, is an elastic portion 34, the shock sensation when the stopper member 30 and the housing portion 82 come into contact is adjusted by the elasticity of the elastic portion 34. In particular, in this embodiment, since the contact surface of the stopper member 30 with the housing portion 82 is made of an elastic tip 40, the reduction of impact noise and shock caused by the contact between the stopper member 30 and the housing portion 82 can be achieved more advantageously.

[0086] In this embodiment, the stopper member 30 has a laminated structure in which the elastic portion 34 is provided with a tip elastic body 40 and an intermediate elastic body 42 on both the front and rear sides of the intermediate restraint member 44. Therefore, by setting a large total thickness dimension of the tip elastic body 40 and the intermediate elastic body 42, durability can be improved, while adjusting the spring of the elastic portion 34 can achieve appropriate stopper characteristics.

[0087] The tip elastic body 40 and the intermediate elastic body 42 that constitute the elastic portion 34 are both made of a harder material than the main rubber elastic body 16. Therefore, sufficient durability of the tip elastic body 40 and the intermediate elastic body 42 is ensured in the stopper member 30, which is subjected to a large load due to the brake.

[0088] Mounting bolts 48 for fixing the stopper member 30 to the inner shaft member 12 pass through the inner shaft member 12 and are screwed into the base portion 32 of the stopper member 30. The tip surface of the stopper member 30, which is composed of a tip elastic body 40, is a stopper contact surface 46 composed of a smooth, continuous curved surface without holes. Therefore, the contact area between the tip surface of the stopper member 30 and the inner circumferential surface of the housing portion 82 can be efficiently increased, and the durability of the tip elastic body 40 can be improved by distributing stress.

[0089] Figures 8 and 9 show a second embodiment of a cylindrical elastic coupling device for shafts and beams, which has a structure according to the present invention, and a rubber bushing 90 for shafts and beams. The rubber bushing 90 for shafts and beams has a structure in which an inner shaft member 92 and outer divided parts 14a and 14b are connected by a main rubber elastic body 16, and a stopper member 94 is attached to the inner shaft member 92. In the following description, components and parts that are substantially the same as those in other embodiments will be denoted by the same reference numerals in the figures and their description will be omitted.

[0090] The inner shaft member 92 of the shaft beam rubber bush 90 has a bolt insertion hole 96 that penetrates radially. In this embodiment, the bolt insertion hole 96 is a threaded portion with screw threads formed on the inner circumferential surface along the entire length in the penetrating direction, and a mounting bolt 108, which will be described later, can be screwed into it.

[0091] The stopper member 94 has a structure in which an elastic portion 100 is fixed to the front surface of the base portion 98. The base portion 98 is plate-shaped and curves in the circumferential direction of the inner shaft member 92. The base portion 98 has a bolt hole 102 that penetrates through the central part in the front-to-back direction, which is the thickness direction of the plate. The bolt hole 102 has a larger diameter at the tip end, thereby forming a stepped surface 104 around its entire circumference.

[0092] The elastic portion 100, like the elastic portion 34 of the first embodiment, is a laminated structure in which a rigid intermediate restraining member 44 is fixed between a tip elastic body 40 and an intermediate elastic body 42, both made of an elastic material. The elastic portion 100 of this embodiment is provided with a tip open hole 106 that penetrates in the lamination direction. The tip open hole 106 is connected in series with a bolt hole 102 of the base portion 98, and the bolt hole 102 is open to the tip side through the tip open hole 106.

[0093] The stopper member 94 has a base 98 that is fixed to the inner shaft member 92 by a separate mounting bolt 108. The mounting bolt 108 has a shaft portion 110 with threads formed on its outer circumference and a head portion 112 which is larger in diameter than the shaft portion 110. The shaft portion 110 is insertable into the bolt hole 102 of the stopper member 94 and can be screwed into the bolt insertion hole 96 of the inner shaft member 92. The length of the shaft portion 110 is shorter than the bolt insertion hole 96 of the inner shaft member 92. The head portion 112 is insertable into the open tip hole 106 of the stopper member 94 and is sized so that it cannot be inserted beyond the stepped surface 104 of the bolt hole 102 on the base end side (rear side).

[0094] With the stopper member 94 superimposed on the outer circumferential surface of the inner shaft member 92 from the front, a mounting bolt 108, inserted through the open-end hole 106, is threaded through the bolt hole 102 of the base portion 98 of the stopper member 94, protruding rearward from the base portion 98, and screwed into the bolt insertion hole 96 of the inner shaft member 92. In this way, the stopper member 94 is fixed to the inner shaft member 92 by the mounting bolt 108. The mounting bolt 108 may be inserted in a threaded state along the entire length of the bolt insertion hole 96, but it is preferable that it be partially inserted and screwed in for a predetermined length from the open end on the stopper member 94 side. Preferably, the mounting bolt 108 is threaded in a range of 1 / 8 or more and 1 / 2 or less of the entire length of the bolt insertion hole 96.

[0095] The head 112 of the mounting bolt 108 is housed in the large-diameter portion of the bolt hole 102 and the open tip hole 106, and does not protrude forward beyond the tip surface of the stopper member 94. Furthermore, since the head 112 of the mounting bolt 108 is housed in the bolt hole 102 and the open tip hole 106, it is possible to apply rotational torque, for example, through grooves or recesses opening on the end face.

[0096] As with the rubber bushing 90 for the shaft beam having a structure according to this embodiment, a screw thread can also be formed on the inner circumferential surface of a bolt insertion hole 96 that penetrates the inner shaft member 92 radially, and the stopper member 94 can be attached to the inner shaft member 92 by a mounting bolt 108 that is screwed into the screw thread. This allows the stopper member 94 to be fixed to the inner shaft member 92 without requiring a separate nut.

[0097] As shown in this embodiment, the mounting bolt for attaching the stopper member to the inner shaft member is not necessarily limited to being inserted from the opposite side of the stopper member into the bolt insertion hole of the inner shaft member, which is a through hole, but may also be inserted from the stopper member side. If the mounting bolt is inserted into the bolt insertion hole from the tip side of the stopper member, the direction in which the stopper member is superimposed on the inner shaft member and the direction in which the mounting bolt is inserted into the bolt insertion hole are the same, so the stopper member can be easily attached from one direction. In particular, if the process of attaching the stopper member to the inner shaft member is an automated process, for example by a robot, there is no need to change the orientation of the shaft beam rubber bush, and the stopper member can be attached with simpler control.

[0098] Since the bolt insertion hole 96 is a through hole that penetrates the inner shaft member 92 in a direction perpendicular to the axis, it is possible to prevent cleaning fluid, for example, when cleaning the inner shaft member 92 from remaining in the bolt insertion hole 96. Furthermore, in this embodiment, the bolt hole 102 and the tip opening hole 106 formed in the stopper member 94 are also through holes, so it is difficult for cleaning fluid, for example, when cleaning the stopper member 94 to remain in the bolt hole 102 and the tip opening hole 106. In particular, in this embodiment, since the bolt hole 102 and the tip opening hole 106 of the stopper member 94 have a smooth cylindrical inner surface without threads, the retention of liquid is more advantageously prevented.

[0099] Figures 10 and 11 show a third embodiment of a cylindrical elastic coupling device for shafts and beams, which has a structure according to the present invention, and is a rubber bushing 120 for shafts and beams. The rubber bushing 120 for shafts and beams has a structure in which a stopper member 94 is attached to an inner shaft member 122.

[0100] A bolt insertion hole 124 is formed in the inner shaft member 122. The bolt insertion hole 124 comprises a threaded portion 126 with screw threads formed on its inner circumferential surface, and a connecting portion 128 provided in series with the threaded portion 126 and without screw threads on its inner circumferential surface. The threaded portion 126 is partially provided in the direction of penetration of the bolt insertion hole 124 and constitutes the end of the bolt insertion hole 124 on the side to which the stopper member 94 is attached, and opens at the front on the outer circumferential surface of the inner shaft member 122. The connecting portion 128 extends from the threaded portion 126 toward the opposite side of the stopper member 94 and opens at the rear on the outer circumferential surface of the inner shaft member 122. The connecting portion 128 may have approximately the same diameter as the threaded portion 126, or it may have a different diameter. Furthermore, the cross-sectional shape of the hole in the connecting portion 128 is not particularly limited and may be a circular cross-section similar to that of the threaded portion 126, or it may be a different cross-sectional shape from that of the threaded portion 126, such as a polygon. Preferably, the connecting portion 128 has the same diameter as the threaded portion 126 or a smaller diameter than the threaded portion 126.

[0101] Similar to the second embodiment, the stopper member 94 is fixed to the inner shaft member 122 by screwing a mounting bolt 108, which is inserted from the front through the open tip hole 106 and bolt hole 102 of the stopper member 94, into the threaded portion 126 of the bolt insertion hole 124 in the inner shaft member 122. In this embodiment, the threaded portion 126 is longer than the portion into which the shaft portion 110 of the mounting bolt 108 is screwed, so that the shaft portion 110 is screwed into the front end portion of the threaded portion 126 without protruding rearward.

[0102] According to the shaft beam rubber bush 120 of this embodiment, similar to the first and second embodiments, the residue of cleaning fluid, etc., in the bolt insertion hole 124 of the inner shaft member 122 is prevented, thereby avoiding problems such as corrosion. Furthermore, the residue of cleaning fluid, etc., in the tip opening hole 106 and bolt hole 102 of the stopper member 94 is also prevented.

[0103] In this embodiment, the bolt insertion hole 124 has a threaded portion (threaded portion 126) for the mounting bolt 108 provided only in a part of its length, and the portion into which the mounting bolt 108 is not inserted is a non-threaded communication portion 128, thus avoiding irregularities on the inner circumferential surface. Therefore, liquid residue is less likely to occur, especially in the communication portion 128, and the liquid can be efficiently discharged from the bolt insertion hole 124 by blowing air from the threaded portion 126 side, where liquid residue is relatively more likely to occur, using a blower.

[0104] The bolt insertion hole 124 is a through hole that penetrates the inner shaft member 122 in the direction perpendicular to the axis, and is equipped not only with a partially threaded portion 126 provided in the direction perpendicular to the axis, but also with a connecting portion 128 that extends in series from the threaded portion 126. This makes it easier to prevent cutting chips from accumulating in the bolt insertion hole 124 when forming the threads of the threaded portion 126 by cutting, compared to the case of a bottomed hole, and prevents defects in thread formation due to residual cutting chips. In addition, because the bolt insertion hole 124 is a through hole, defects such as cutting defects in the threaded portion 126 can be easily visually checked.

[0105] Figures 12 and 13 show a fourth embodiment of a cylindrical elastic coupling device for shafts and beams, which has a structure according to the present invention, and is a rubber bushing 130 for shafts and beams. The rubber bushing 130 for shafts and beams has a structure in which a stopper member 94 is attached to an inner shaft member 132.

[0106] The inner shaft member 132 has a bolt insertion hole 134 with a circular cross-section. In this embodiment, the bolt insertion hole 134 is a non-threaded portion in which no threads are formed on the inner circumferential surface along the entire length in the through direction, and the inner circumferential surface is a smooth cylindrical surface without irregularities.

[0107] The stopper member 94 is attached to the inner shaft member 132 by a mounting bolt 136 that passes through the bolt insertion hole 134 of the inner shaft member 132. Similar to the mounting bolt 108 in the second embodiment, the mounting bolt 136 integrally comprises a shaft portion 110 with threads formed on its outer circumference and a head 112 with a larger diameter than the shaft portion 110. The length of the shaft portion 110 of the mounting bolt 136 is longer than that of the mounting bolt 108 and is longer than the length of the bolt insertion hole 134 of the inner shaft member 132. The shaft portion 110 of the mounting bolt 136, which is inserted from the tip side (front side) into the tip open hole 106 and bolt hole 102 of the stopper member 94, passes through the bolt insertion hole 134 of the inner shaft member 132 and protrudes rearward from the inner shaft member 132. The stopper member 94 is bolted to the inner shaft member 132 by screwing a nut 138 onto the rearward protruding portion of the shaft portion 110 of the mounting bolt 136. In this embodiment, the mounting bolt 136 has threads formed along the entire length of the shaft portion 110, but the shaft portion 110 may also have threads formed only on the tip portion (the end opposite to the head 112) where the nut 138 is screwed on. In short, the shaft portion of the mounting bolt may have threads only partially provided.

[0108] Since the bolt insertion hole 134 penetrates the inner shaft member 132, cleaning fluid and the like can be easily discharged to the outside by blowing air or other means. Moreover, since the bolt insertion hole 134 in this embodiment has a smooth inner circumferential surface shape without threads, cleaning fluid and the like are less likely to remain inside the hole.

[0109] For example, the nut 138 can be inserted into the open hole 106 at the tip of the stopper member 94 from the tip side, and the mounting bolt 136, which is inserted from the rear into the bolt insertion hole 134 of the inner shaft member 132, can be screwed onto the nut 138 to fix the stopper member 94 and the inner shaft member 132.

[0110] Although embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, the mounting bolt may be a hexagonal bolt with a hexagonal prism-shaped head. Furthermore, the tool for tightening the mounting bolt is selected according to the structure of the mounting bolt and is not limited to a hexagonal wrench. For example, if the mounting bolt is a hexagonal bolt, a socket wrench that holds and rotates the outer surface of the head may be used.

[0111] The stopper member may be fixed to the inner shaft member by multiple mounting bolts. This prevents relative rotation of the stopper member around the mounting bolts relative to the inner shaft member. The mounting bolts may be fixed to the bolt insertion holes with adhesive, adhesive may be used to reinforce the screw-fitting, or the inner shaft member and the stopper member may be connected solely by adhesive without being screwed into the bolt insertion holes, the stopper member, or a separate nut.

[0112] The head of the mounting bolt does not necessarily have to be superimposed on a flat seating surface; it may be superimposed on the outer circumferential surface of the cylindrical inner shaft member. Alternatively, a separate seating surface component can be interposed between the head of the mounting bolt and the inner shaft member, with one surface corresponding to the outer circumferential surface of the inner shaft member and the other surface corresponding to the front end surface of the mounting bolt head.

[0113] As shown in Figure 14, the shaft beam rubber bush 140 is a cylindrical elastic coupling device for shaft beams. In this structure, the overlapping surface of the inner shaft member 142 with the base 146 of the stopper member 144 is a first rotation-permissible surface 148, which is a stopper seat surface formed by a plane that extends perpendicular to the central axis of the bolt insertion hole. The overlapping surface of the base 146 of the stopper member 144 with the inner shaft member 142 is a second rotation-permissible surface 150, which is a plane that corresponds to the first rotation-permissible surface 148. In this configuration, the rotation of the inner shaft member 142 and the stopper member 144 around the central axis of the bolt insertion hole 24 (mounting bolt 48) is permitted by the first and second rotation-permissible surfaces 148 and 150. Thus, a rotation limiting mechanism that positions the stopper member and the inner shaft member around the central axis of the bolt insertion hole (mounting bolt) is not essential. Furthermore, if a rotation limiting mechanism is not provided as shown in Figure 14, for example, if the tip surface of the stopper member is made to have a rotationally symmetrical shape with respect to the central axis of the mounting bolt, such as a spherical crown shape, then even if the stopper member is mounted in any orientation around the mounting bolt, changes in the contact manner between the stopper member and the housing can be suppressed, thereby ensuring stabilization of the stopper action and durability.

[0114] In the shaft beam rubber bushing 140 shown in Figure 14, the overlapping surface between the inner shaft member 142 and the stopper member 144 is a plane that extends perpendicular to the central axis of the mounting bolt 48, and the overlapping surface between the head 52 of the mounting bolt 48 and the inner shaft member 142 is also a plane that extends perpendicular to the central axis of the mounting bolt 48. Therefore, the fastening force of the mounting bolt 48 is less likely to generate a component force other than the central axis direction of the mounting bolt 48, and the fixing force of the stopper member 144 to the inner shaft member 142 can be efficiently obtained. In addition, it becomes easier to mount the mounting bolt 48 and the stopper member 144 in the correct orientation without tilting relative to the inner shaft member 142.

[0115] As shown in Figure 15, the rubber bush 160 for shaft beams, which is a cylindrical elastic coupling device for shaft beams, can also have an open tip hole 164 that opens to the tip surface of the stopper member 162. The stopper member 162 has a screw hole 166 that penetrates the base portion 32 in the front-rear direction and opens to the base end surface. The stopper member 162 also has an open tip hole 164 that penetrates the elastic portion 34 and opens to the tip surface. The screw hole 166 of the base portion 32 and the open tip hole 164 of the elastic portion 34 are in series communication in the front-rear direction, and the screw hole 166 and the open tip hole 164 constitute a stopper through-hole 168 that penetrates the entire stopper member 162 in the front-rear direction. In the rubber bush 160 for shaft beams shown in Figure 15, screw threads are formed on the inner circumferential surface of the screw hole 166, while the inner circumferential surface of the open tip hole 164 is a smooth cylindrical surface without screw threads.

[0116] According to the shaft beam rubber bush 160 shown in Figure 15, since the tip opening hole 164 is provided on the tip surface of the stopper member 162, it is possible to adjust the stopper characteristics by using the tip opening hole 164 on the tip surface of the stopper member 162 to adjust, for example, the size, depth, and shape of the tip opening hole 164.

[0117] Furthermore, because the screw hole 166 penetrates the base 32 of the stopper member 162, when the metal base 32 is cleaned with a liquid such as water, for example, liquid is less likely to remain in the screw hole 166, thus preventing problems such as corrosion of the base 32 due to liquid residue. Also, because the tip opening hole 164 penetrates the intermediate restraint member 44, when the metal intermediate restraint member 44 is cleaned with a liquid such as water, for example, liquid is less likely to remain in the tip opening hole 164, thus preventing problems such as corrosion due to liquid residue. In particular, since the inner circumferential surface of the tip opening hole 164 formed in the intermediate restraint member 44 is a smooth cylindrical surface without screw threads, liquid residue is prevented more effectively. Note that the inner circumferential surface of the tip opening hole 164 formed in the intermediate restraint member 44 may have screw threads similar to those on the inner circumferential surface of the screw hole 166.

[0118] Furthermore, the tip opening that opens to the tip surface of the stopper member does not necessarily have to penetrate the elastic part; it may be a non-penetrating concave shape that opens to the tip surface. Also, for example, if the elastic part has a laminated structure having a tip elastic body, an intermediate restraining member, and an intermediate elastic body, the concave tip opening may be formed only in the tip elastic body, or it may be formed to a depth that reaches the intermediate restraining member, or it may be formed to a depth that reaches the intermediate elastic body. Moreover, the tip opening is not limited to being formed only in the elastic part; it may also be formed to a depth that reaches the base.

[0119] The mounting bolt may be fixedly attached to the stopper member by being integrally molded or otherwise. Alternatively, the mounting bolt provided on the stopper member may be passed through the bolt insertion hole to the inner shaft member, and the stopper member may be tightened and fixed to the inner shaft member with a nut member screwed onto the tip, or a female thread may be formed on the inner circumferential surface of the bolt insertion hole, and the mounting bolt provided on the stopper member may be screwed into the female thread of the bolt insertion hole to fix it in place.

[0120] Alternatively, a separate mounting bolt may be inserted from the tip side through a stopper through-hole that penetrates the stopper member, and the mounting bolt may be screwed into the bolt insertion hole of the inner shaft member, which has a female thread structure, as shown in the second and third embodiments in Figures 8 to 11, or it may be tightened and fixed with a nut member screwed onto the mounting bolt that penetrates the inner shaft member, as shown in the fourth embodiment in Figures 12 and 13. In this case, the stopper through-hole that penetrates the stopper member may have threads formed on at least a part of its inner circumferential surface for screwing with the mounting bolt, or the entire inner circumferential surface may be a smooth cylindrical surface without threads.

[0121] For example, a separate intermediate member can be interposed between the inner shaft member and the stopper member, with one side corresponding to the outer circumferential surface of the inner shaft member and the other side corresponding to the base end surface (rear end surface) of the stopper member.

[0122] The elastic portion of the stopper member is not necessarily limited to a laminated structure as in the first embodiment, but may be a single-layer structure formed entirely of an elastic material. Furthermore, when a laminated elastic portion is used, the number of layers is not particularly limited.

[0123] 10 Rubber bushing for shaft beam (First embodiment of cylindrical elastic coupling device for shaft beam) 12 Inner shaft member 14a, 14b Outer split body 16 Main rubber elastic body 18 Central shaft body 20 Inner flange 22 Mounting part 24 Bolt insertion hole 26 Bolt seating surface 28 Bolt hole 30 Stopper member 32 Base 34 Elastic part 36 Inner side corresponding surface 38 Screw hole 40 Tip elastic body 42 Intermediate elastic body 44 Intermediate restraining member 46 Stopper contact surface 48 Mounting bolt 50 Shaft part 52 Head 54 Outer flange 56 Window part 58 Opening 60 Rubber flange 62 (62a, 62b) Pocket part 64 Annular groove 66 Protruding part 68 Trolley 70 Trolley frame 72 Wheel 74 Axle 76 Axle box 78 Axle spring 80 Axle beam 82 Housing 84a, 84b Semi-cylindrical member 86 Brake device 88 Brake shoe 90 Rubber bushing for axle beam (Second embodiment of cylindrical elastic coupling device for axle beam) 92 Inner axle member 94 Stopper member 96 Bolt insertion hole 98 Base 100 Elastic part 102 Bolt hole 104 Stepped surface 106 Open tip hole 108 Mounting bolt 110 Axle part 112 Head 120 Rubber bushing for axle beam (Third embodiment of cylindrical elastic coupling device for axle beam) 122 Inner axle member 124 Bolt insertion hole 126 Threaded part 128 Communicating part 130 Rubber bushing for axle beam (Fourth embodiment of cylindrical elastic coupling device for axle beam) 132 Inner axle member 134 Bolt insertion hole 136 Mounting bolt 138 Nut 140 Rubber bushing for shaft beam (another embodiment of cylindrical elastic coupling device for shaft beam) 142 Inner shaft member 144 Stopper member 146 Base 148 First rotation-permissible surface (stopper seating surface) 150 Second rotation-permissible surface 160 Rubber bushing for shaft beam (another embodiment of cylindrical elastic coupling device for shaft beam) 162 Stopper member 164 Open tip hole 166 Screw hole 168 Stopper through hole

Claims

1. A cylindrical elastic coupling device for an axle beam, wherein a pair of outer segments facing each other perpendicular to the axis are arranged on the outer circumference of an inner axle member, and the inner axle member and the pair of outer segments are elastically connected to each other by a main rubber elastic body, the inner axle member is attached to the bogie frame of a railway vehicle, and the pair of outer segments are attached to a cylindrical housing portion provided at one end of the axle beam, thereby elastically connecting the bogie frame and the axle beam, wherein a stopper member is attached to the inner axle member to limit the relative displacement between the inner axle member and the pair of outer segments in either the front-rear direction of the railway vehicle by contact with the housing portion, a bolt insertion hole is formed in the inner axle member that penetrates in the direction perpendicular to the axis, and the stopper member and the inner axle member are fixed to each other by a mounting bolt inserted through the bolt insertion hole.

2. The tip surface of the stopper member that contacts the housing portion is a smoothly continuous stopper contact surface, as described in claim 1.

3. The cylindrical elastic coupling device for an axial beam according to claim 1, wherein the stopper member has an open tip hole formed on the tip surface that contacts the housing portion.

4. The cylindrical elastic coupling device for a shaft beam according to claim 3, wherein at least a portion of the bolt insertion hole of the inner shaft member is a threaded portion with screw threads formed on its inner circumferential surface, and the mounting bolt inserted from the tip open hole and passing through the stopper member is screwed into the threaded portion of the bolt insertion hole.

5. The cylindrical elastic coupling device for an axial beam according to claim 4, wherein the threaded portion is provided along the entire length of the bolt insertion hole in the through direction.

6. The cylindrical elastic coupling device for an axial beam according to claim 4, wherein the threaded portion is partially provided in the direction of passing through the bolt insertion hole.

7. The cylindrical elastic coupling device for an axial beam according to claim 3, wherein the entire bolt insertion hole is a non-threaded portion, and the mounting bolt inserted from the open tip hole and passing through the stopper member passes through the bolt insertion hole and is screwed into a nut located on the radially opposite side of the stopper member.

8. The cylindrical elastic coupling device for an axial beam according to any one of claims 1 to 3, wherein the entire bolt insertion hole is a non-threaded portion, and the mounting bolt inserted into the bolt insertion hole from the radially opposite side of the stopper member is screwed into a threaded hole provided in the stopper member.

9. The cylindrical elastic coupling device for a shaft beam according to any one of claims 1 to 3, wherein the inner shaft member is provided with a bolt seat surface on the radially opposite side of the stopper member, which is composed of a plane extending perpendicular to the through-direction of the bolt insertion hole, and onto which the head of the mounting bolt is superimposed.

10. The cylindrical elastic coupling device for a shaft beam according to any one of claims 1 to 7, wherein the overlapping surface of the stopper member on the inner shaft member is a stopper seat surface formed by a plane that extends perpendicularly to the central axis of the mounting bolt.

11. The cylindrical elastic coupling device for a shaft beam according to any one of claims 1 to 7, wherein the stopper member comprises a rigid base that is bolted to the inner shaft member, and the stopper member comprises an elastic portion fixed to the tip side of the base and constituting the tip surface of the stopper member.

12. The cylindrical elastic coupling device for a axial beam according to claim 11, wherein the elastic part is made of a material harder than the main body rubber elastic body.

13. The cylindrical elastic coupling device for an axial beam according to claim 11, wherein the elastic portion of the stopper member is a laminated structure comprising a tip elastic body constituting the tip surface of the stopper member, an intermediate elastic body fixed to the tip side of the base, and a rigid intermediate restraining member disposed between the tip elastic body and the intermediate elastic body.

14. The cylindrical elastic coupling device for an axial beam according to claim 13, wherein the tip elastic body and the intermediate elastic body are formed of the same elastic material.

15. The cylindrical elastic coupling device for an axial beam according to any one of claims 1 to 7, wherein one of the pair of outer divided bodies has a window portion that penetrates radially, and the stopper member is exposed through the window portion.

16. The cylindrical elastic coupling device for an axial beam according to claim 15, wherein the other of the pair of outer divisions has a radially penetrating opening, and the pair of outer divisions are all the same shape.

17. The cylindrical elastic coupling device for an axial beam according to any one of claims 1 to 3, 7, wherein the inner circumferential surface of the bolt insertion hole is a smoothly continuous cylindrical surface.

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