JP2020159530A - Buffer member of shaft joint for railroad vehicle, and shaft joint for railroad vehicle - Google Patents

Abstract

To improve durability of a buffer member of a shaft joint for a railroad vehicle, reduce a replacement frequency of the buffer member, and reduce the wear of a central plate.SOLUTION: A buffer member of a shaft joint for a railroad vehicle comprises: a pair of inside members that is provided at the shaft end parts of a drive shaft and a driven shaft facing each other on the same shaft, and faces each other; an outside member that surrounds the pair of inside members and engages with the inside member in a rotation transmission direction; and a center plate that is fixed to the outside member, and arranged between the inside members. The buffer member further comprises an elastic part 2 with elasticity that is attached to the inside member or the center plate, and a sliding part 3 whose surface is in contact with another member where the relative speed difference of the elastic part occurs is covered with a low friction material.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cushioning member used for a shaft joint that transmits the rotation of a motor that is a part of a drive device of a railway vehicle to a gearbox, and a shaft joint for a railway vehicle. More specifically, the present invention relates to a cushioning member that can be used for various shaft joints such as a gear type and a flat plate type, and a shaft joint for a railway vehicle.

A joint is provided between the motor fixed to the bogie and the gear box integrated with the axle to absorb ups and downs of the vehicle body and phase shift during meandering (see, for example, Patent Document 1). ).

In the case of a gear-type deflection shaft joint, it is composed of a pair of inner (external gear) members that mesh with the motor shaft and gear device small gear shaft, and an outer cylinder (internal gear member) that meshes with the external gear and is freely variable. A partition called a center plate is provided so that the inner members do not collide with each other when displaced in the axial direction or the vertical direction. Further, the inner member is provided with a cushioning member made of synthetic rubber at a position facing the center plate in order to reduce the impact at the time of contact with the center plate.

Japanese Unexamined Patent Publication No. 2001-65589

However, in the case of this type of railroad vehicle shaft joint, the cushioning member and the center plate come into contact at different distances from the center (parts with different radii) due to the displacement of the joint. The center plate is rubbed. Moreover, railroad vehicle joints are used under harsh conditions such as rotating at high speeds exceeding 5000 rpm and receiving high loads. For this reason, the cushioning member is strongly struck and rubbed against the center plate for each rotation, so that the surface of the cushioning member may be worn like a pockmark. This wear phenomenon is particularly remarkable in mountainous areas with many curves and high-speed vehicles. If this wear becomes excessive, the inner member and the center plate come into direct contact with each other, and there is a risk that the inner members may collide with each other, resulting in an accident. Therefore, it is necessary to replace the cushioning member frequently.

An object of the present invention is to improve the durability of a cushioning member of a shaft joint for a railway vehicle. Another object of the present invention is to provide a shaft joint for a railway vehicle capable of reducing the frequency of replacement of the cushioning member and also reducing the wear of the central plate.

A cushioning member for a shaft joint for a railroad vehicle that achieves such an object is provided at each shaft end of a drive shaft and a driven shaft facing each other on the same shaft, and surrounds a pair of inner members facing each other and a pair of inner members. In addition, in a cushioning member of a shaft joint for a railway vehicle having an outer member that engages with the inner member in the rotation transmission direction and a center plate that is fixed to the outer member and arranged between the inner members, the inner member or the center plate. It has an elastic portion having elasticity and a sliding portion whose surface in contact with a mating member that causes a relative speed difference of the elastic portion is covered with a low friction material.

Here, the sliding portion is preferably made of a coating material of polytetrafluoroethylene, and more preferably a sheet of polytetrafluoroethylene.

Further, the elastic portion is preferably made of synthetic rubber.

Further, the cushioning member is formed of a synthetic rubber material or a material containing a lubricant in a synthetic resin material, and the lubricant is present at least in a portion in contact with the inner member or the central plate to form a sliding portion. It may be done.

Further, the shaft joint for a railway vehicle of the present invention includes the cushioning member according to any one of claims 1 to 5.

Further, in the shaft joint for a railway vehicle, it is preferable that the contact portion of the center plate with the cushioning member is covered with a low friction material.

According to the cushioning member of the shaft joint for a railway vehicle according to the present invention, the frictional force at the time of contact is reduced, so that the durability of the cushioning member is improved and the frequency of replacement of the cushioning member can be reduced. At the same time, according to the cushioning member of the shaft joint for a railway vehicle according to the present invention, the wear of the center plate can be reduced.

It is a central vertical sectional view which shows one Embodiment of the cushioning member of the deflection shaft joint which concerns on this invention. It is a central vertical sectional view which shows one Embodiment of the shaft joint for railroad vehicles which concerns on this invention. It is a central vertical sectional view which shows the other embodiment of the shaft joint for a railroad vehicle which concerns on this invention. It is a front view which shows the test result of the cushioning member of the flexible shaft joint which concerns on this invention, (A) shows the state before a test, (B) shows the state after a test. It is a front view which shows the deterioration state of the cushioning member of the conventional flexible shaft joint.

Hereinafter, the configuration of the present invention will be described in detail based on the embodiments shown in the drawings.

FIG. 1 shows an example of an embodiment of a cushioning member for a shaft joint for a railway vehicle of the present invention. The cushioning member 1 according to this embodiment comes into contact with an elastic portion 2 having elasticity attached to an inner member or a center plate of a shaft joint for a railway vehicle and a mating member in which a relative speed difference between the elastic portions 2 occurs. A sliding portion 3 whose surface is covered with a low friction material 4 is provided.

The cushioning member 1 of the present embodiment is mounted on, for example, the upper surface of a nut for fastening an inner member facing the center plate of a shaft joint for a railroad vehicle, and has an annular shape and four corners formed in an arc shape. It has an almost rectangular cross section, and the elastic part 2 is fitted into the annular recess around the screw hole on the upper surface of the hexagon nut so that the sliding part 3 side protrudes from the upper surface of the nut toward the center plate. Is to be done. The shape of the cushioning member 1 is not particularly limited to the annular shape shown in the figure, and an appropriate shape can be adopted depending on the structure and shape of the mating member to which the annular member 1 is attached. For example, it may be a cap structure that covers the upper surface of the fastening nut and the shaft end surface of the male screw, or the planar shape may be various shapes such as a polygonal shape, a rectangular shape, or a circular shape. Further, the cushioning member 1 is not limited to a specific shape even when it is mounted on the center plate, and may be formed into various shapes such as a flat disk shape, a polygonal shape, and a rectangular shape. It may be formed as an annular shape or a polygonal annular shape depending on the case. Further, not only the surface in contact with the mating member in which the relative velocity difference occurs, but also the outer region thereof may be formed into a film to cover the entire surface of the central plate.

The elastic portion 2 reduces the impact at the time of contact between the drive shaft side member and the driven shaft side member of the shaft joint for a railway vehicle, and requires an appropriate cushioning property. In this embodiment, a solid ring member made of nitrile rubber is used. As a result, a stable elastic force due to the rubber elasticity of the material itself can be obtained for a long period of time, and the durability of the cushioning member 1 is improved. Of course, the elastic portion 2 may be another synthetic rubber material or a resin material having elasticity. Further, the elastic portion 2 may have structural elasticity by adopting not only the elastic force of the material but also a shape having a cavity inside or a shape having a bellows-shaped wall portion, for example.

As the low friction material 4 constituting the sliding portion 3, various synthetic resins having a lower friction than the synthetic rubber material can be generally used. For example, as a plastic-based sliding material, fluororesins such as polyacetal (POM), polyamide (PA), and polytetrafluoroethylene (PTFE, trade name Teflon (registered trademark) of DuPont) are generally used, but other materials are used. Also, polyphenylene sulfide (PPS), elastomer-based, polyolefin-based, thermosetting resins, and other superempuras can be used. The friction coefficient of polytetrafluoroethylene is about 0.04, which is about 1/20 of the friction coefficient of the synthetic rubber of the elastic portion 2, and sufficient friction characteristics can be obtained. Further, for example, nylon has a friction coefficient of about 0.24, and an effect can be expected as compared with synthetic rubber. On the other hand, in the sliding portion 3, the contact pressure of the used portion is extremely high and a large frictional force is generated, and since the contact pressure is high, minute wrinkles due to stick slip are likely to occur on the surface, and in addition, cushioning as a cushioning member The effect is needed. For this reason, it is preferable that the low friction material 4 constituting the sliding portion 3 has excellent friction characteristics and has appropriate hardness and flexibility. For this reason, it is preferable to use a fluororesin. Examples of the fluororesin include polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroquil vinyl ether copolymer (PFA), tetrafluoroethylene / hexanefluoropropylene copolymer (FEP), and tetrafluoroethylene. Examples thereof include ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and the use of PTFE is preferable.

The sliding portion 3 is preferably a coating of a low friction material 4 that covers the elastic portion 2. For example, among the fluororesins, it is preferably made of a coating of polytetrafluoroethylene (PTFE). The PTFE coating is formed, for example, by coating the elastic portion 2 to form a thin film (Teflon coating), or by attaching a sheet (Teflon sheet) in which molding powder is hardened by adhesion or the like, but it can be formed by coating. Since the thickness of the thin film is limited and the durability is slightly inferior, it is preferable to attach a sheet capable of ensuring a sufficient thickness. Furthermore, since PTFE is easily worn and easily creeps, when used as a sliding material, a filler such as glass fiber, graphite, bronze, carbon fiber, molybdenum disulfide, or a special filler is mixed and used. Is preferable. The wear resistance can be further improved by using a solid lubricant, an oxide, or the like in combination.

Here, the thicker the Teflon sheet, the more advantageous it is for wear, but if it is too thick, the elasticity as a cushioning member cannot be obtained and the cushioning effect becomes small. Therefore, it is preferable to set an appropriate thickness, for example, 1 mm or less.

The sliding portion 3 is the entire circumference of the surface in contact with the mating member in which the relative speed difference of the elastic portion 2 occurs (that is, the surface facing the center plate in the case of the present embodiment in which the cushioning member 1 is attached to the inner member). It is preferable to form them continuously, but in some cases, they may be formed discontinuously in the circumferential direction. For example, a plurality of sliding portions 3 may be arranged at equal intervals discontinuously in the circumferential direction on the surface of the annular elastic portion 2, that is, the surface in contact with the mating member in which the relative speed difference occurs. Further, the cushioning member 1 itself may be formed in a discontinuous shape, for example, in a block shape and arranged in an annular shape on a surface that may come into contact with a mating member that causes a relative speed difference.

In the cushioning member 1 configured as described above, the frictional force when the sliding portion 3 comes into contact with the mating member in which a relative speed difference occurs is reduced, and therefore, in the case of a coated material made of fluororesin, the frictional force is reduced. Since a high friction reducing effect can be obtained, a long-term friction reducing effect can be obtained. Therefore, if the cushioning member of the present embodiment is applied to, for example, a gear-shaped flexible shaft joint for a railway vehicle, the frequency of replacement of the cushioning member 1 can be reduced.

FIG. 2 shows an embodiment of a flexible shaft joint to which the cushioning member of the present embodiment is applied. The deflection shaft joint 11 according to this embodiment is a gear-type deflection shaft joint for a railway vehicle, and is a drive shaft (for example, a motor shaft) 12 and a driven shaft (for example, a motor shaft) 12 arranged so as to face each other on the same shaft. A pair of inner members 18 and 19 provided at the respective shaft ends of the gear shaft) 13 and an outer side surrounding the pair of inner members 18 and 19 and engaging with the inner members 18 and 19 in the rotation transmission direction, respectively. It includes members 20 and 21 and a center plate 6 fixed to the outer members 20 and 21 and arranged between the inner members 18 and 19.

In the case of the present embodiment, the inner member is an inner cylinder 18 and 19 having crowned immediate tooth external gears 14 and 15, and the outer member meshes with the external gears 14 and 15 of the inner cylinders 18 and 19, respectively. The outer cylinders 20 and 21 provided with the internal gears 16 and 17 of the immediate teeth, and the lubricating oil sealed in the space 22 inside the outer cylinders 20 and 21 by the oil drains 23 provided at both ends of the outer cylinders 20 and 21. It has a structure that prevents the outflow (not shown).

The inner cylinders 18 and 19 are attached to the drive shaft 12 and the driven shaft 13 by taper shrink fitting, and are further attached to the fastening bolts 27 and 29 formed at the respective shaft ends of the drive shaft 12 and the driven shaft 13, respectively. The fastening nuts 28 and 30 are screwed together and fixed. As a result, the inner cylinders 18 and 19 and the outer cylinders 20 and 21 have a connecting structure in which the outer gears 14 and 15 and the inner gears 16 and 17 are meshed so that each axis can be tilted with respect to the inner cylinders 18 and 19. It is said that. Further, oil drains 23 are fastened to both ends of the outer cylinders 20 and 21 by fastening bolts 33. Further, the outer cylinders 20 and 21 divided into two in the axial direction are fastened by the fastening bolt 34 with the central plate 6 interposed between them.

The cushioning member 1 is provided in an annular groove 5 provided around a screw hole on the upper surface of a fastening nut 28, 30 for fixing the inner cylinders 18 and 19, for example, a hexagon nut, to the drive shaft 12 and the driven shaft 13, respectively. The elastic portion 2 is fitted and fixed.

Here, when the cushioning member 1 is mounted on the inner member side, a low-friction covering (hereinafter referred to as a low-friction coating 7) is formed on at least a portion of the center plate 6 in contact with the cushioning member 1. Is preferable. In this case, as compared with the case where the cushioning member 1 is used alone, a higher friction reducing effect of the cushioning member 1 can be obtained, and an effect of further reducing the wear of the center plate 6 can be obtained. Here, as the low friction material forming the low friction coating 7 on the center plate 6, a Teflon sheet may be attached or a Teflon coating may be used as in the sliding portion 3 of the cushioning member 1, for example, disulfide. It may be coated with a low friction material such as molybdenum. In the case of this example, molybdenum disulfide coating is carried out for ease of processing, but the present invention is not particularly limited to this. The coating thickness of the low friction coating 7 is not limited to a specific value because the optimum value differs depending on the material, but for example, in the case of molybdenum disulfide, it is about 5 μm to 100 μm, preferably about 10 μm, and PTFE. In the case of, it is not suitable for coating a thick film, so about 10 μm is preferable. PFA, ETFE, and modified PTFE, which can be coated with a thick film, are excellent in abrasion resistance, and among them, FEP and modified PTFE exhibit good abrasion resistance.

In the above-mentioned gear-shaped flexible shaft joint for railway vehicles, the amount of protrusion of the cushioning member 1, that is, the amount of protrusion from the upper surface or the center plate 6 of the fastening nuts 28 and 30, is, for example, 10 to 30 mm, more preferably 10 to. It should be about 20 mm. If it is smaller than 10 mm, the cushioning effect is insufficient, and if it exceeds 30 mm, there is a risk of hindering the movement of the shaft joint.

According to the above-mentioned gear-type flexible shaft joint for railroad vehicles, even if a radial or axial displacement occurs between the drive shaft 12 and the driven shaft 13 of the flexible shaft joint, the center plate 6 and the cushioning member 1 The impact is mitigated by contact with the sliding portion 3.

In the gear-shaped flexible shaft joint for railway vehicles illustrated in FIG. 2, a test was conducted on the deterioration state of the contact surface of the cushioning member with the center plate. In this test, the cushioning member 1 is attached to the upper surfaces of the hexagon nuts 28 and 30, and molybdenum disulfide (low friction coating 7) is applied to the center of the center plate 6 of the flexible shaft joint, and six types are not applied. (Examples 1 to 4 and Comparative Examples 1 and 2) were tested.
(Example 1)
A combination of a cushioning member in which a Teflon sheet is attached to a sliding portion of an elastic portion made of synthetic rubber and a central plate not coated with molybdenum diversion (Example 2).
A combination of a cushioning member in which a Teflon sheet is attached to a sliding portion of an elastic portion made of synthetic rubber and a central plate coated with difluent molybdenum coating (Example 3).
A combination of a cushioning member having a Teflon coating on the sliding portion of the elastic part made of synthetic rubber and a central plate not having a diversion molybdenum coating (Example 4).
A combination of a cushioning member having a Teflon coating on the sliding part of an elastic part made of synthetic rubber and a central plate having a diversion molybdenum coating (Comparative Example 1).
A combination of a cushioning member (conventional product) consisting only of synthetic rubber elastic parts and a center plate not coated with diversion molybdenum (Comparative Example 2).
A combination of a cushioning member (conventional product) consisting only of synthetic rubber elastic parts and a central plate coated with diversion molybdenum.

(Test results)
The test results are shown in Table 1.

From this test result, no particular abnormality was found in the contact surface of the cushioning member to which the Teflon sheet was attached, regardless of the presence or absence of the diversion molybdenum coating on the center plate (Examples 1 and 2). It became clear that the condition was maintained in good condition (see FIG. 4). Further, in the combination with the central plate coated with molybdenum disulfide (that is, Example 2), as compared with the combination with the central plate not coated with molybdenum disulfide (that is, Example 1), the cushioning member, The amount of wear on both the center plate was small.

Further, when the Teflon-coated buffer member was combined with the molybdenum disulfide-coated center plate (that is, Example 4), the contact surface after the test was considerably worn, but it was practically used. No problematic anomalies were found. On the other hand, in the combination with the center plate not coated with molybdenum (Example 3), although the Teflon coating is worn on the contact surface after the test and hardly remains, the function as a cushioning member is secured. It had been. That is, it turned out that there was no problem in practical use.

On the other hand, in the conventional cushioning member made of only synthetic rubber, the surface after the test is greatly worn and pockmarked regardless of the presence or absence of the diversion molybdenum coating on the center plate (Comparative Example 1 and Comparative Example 2). A crack was generated (see FIG. 5).

For this reason, a coating of a low friction material having a friction coefficient lower than that of the elastic part 2 is applied to the surface of the cushioning member 1 in contact with the mating member where a relative speed difference occurs, that is, the low friction material is attached. When the sliding portion 3 to be used or coated is provided, the function as the cushioning member 1 is ensured to some extent, and further, molybdenum disulfide is provided at the portion of the central plate 6 in contact with the cushioning member 1. It has been clarified that the sliding effect becomes effective by forming the low friction coating 7 such as a coating.

The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the cushioning member 1 is fitted and mounted on the upper surfaces of the fastening nuts (hexagon nuts) 28 and 30 for fixing the inner cylinders 18 and 19 which are inner members to the shafts 12 and 13. Although the description has been mainly given with an example, the present invention is not particularly limited to this, and in some cases, as shown in FIG. 4, the central plate 6 may be provided. In this case, the elastic portion 2 of the cushioning member 1 is fixed to the center of the center plate 6 by, for example, adhesion, while the sliding portion 3 is formed on the surface of the fastening nuts 28, 30 facing the upper surface.

Further, in the above-described embodiment, examples of applying a diversion molybdenum coating to the center of the ring-shaped cushioning member 1 and the center plate 6 to the fastening nuts 28 and 30 have been described, but the present invention is particularly limited. Instead, for example, the cushioning member 1 may be attached to both the fastening nuts 28 and 30 and the center plate 6, or the cushioning member 1 may be attached to only one of the fastening nuts 28 and 30, and the low friction material covering 8 to the other may be attached. It may be omitted.

Further, in the above-described embodiment, the elastic portion 2 and the sliding portion 3 are made of different materials, but the present invention is not particularly limited to this, and the elastic portion 2 can be formed by using the same material. The sliding portions 3 may be integrally formed at the same time. For example, if the buffer member 1 is molded using a material containing a lubricant such as oil, grease, wax, or a solid lubricant mixed in a synthetic rubber material or a synthetic resin material, the relative velocity difference of the elastic portion 2 is different. The sliding portion 3 is formed by seeping out the lubricant on the surface in contact with the mating member. In this case, since the elastic portion 2 and the sliding portion 3 can be integrally formed at the same time, manufacturing becomes easy.

Further, in the above-described embodiment, the cushioning member has been mainly described with reference to an example in which the cushioning member is applied to a gear-type flexible shaft joint for a railway vehicle, but the present invention is not particularly limited to this, and is not particularly limited to the flat plate type shaft joint and other uses. It is also possible to apply it to gear-shaped deflection shaft joints and the like.

1 Cushioning member 2 Elastic part 3 Sliding part 4 Low friction material 5 Recessed part 6 Center plate 7 Low friction coating that comes into contact with the sliding part of the cushioning member

Claims (7)

A pair of inner members facing each other at the shaft ends of the drive shaft and the driven shaft facing each other on the same shaft, surrounding the pair of inner members and engaging with the inner members in the rotation transmission direction, respectively. In a cushioning member of a shaft joint for a railroad vehicle including an outer member and a center plate fixed to the outer member and arranged between the inner members.
It has an elastic portion having elasticity attached to the inner member or the center plate, and a sliding portion whose surface in contact with a mating member that causes a relative speed difference between the elastic portions is covered with a low friction material. A cushioning member for a shaft joint for a railway vehicle, which is characterized in that. The cushioning member for a shaft joint for a railway vehicle according to claim 1, wherein the sliding portion is made of a coating material of polytetrafluoroethylene. The cushioning member for a shaft joint for a railway vehicle according to claim 2, wherein the covering is a sheet of polytetrafluoroethylene. The cushioning member for a shaft joint for a railway vehicle according to any one of claims 1 to 3, wherein the elastic portion is made of synthetic rubber. The cushioning member is formed of a synthetic rubber material or a material containing a lubricant in a synthetic resin material, and the lubricant is present at least in a portion of contact with the inner member or the central plate and a sliding portion. The cushioning member for a shaft joint for a railroad vehicle according to claim 1, wherein is formed. A shaft joint for a railway vehicle provided with the cushioning member according to any one of claims 1 to 5. The shaft joint for a railway vehicle according to claim 6, further comprising covering a contact portion of the center plate with the cushioning member with a low friction material.