End cap assembly and shaft box arrangement

Abstract

The invention relates to an end cap assembly for a shaft box device and to a shaft box device. The end cap assembly comprises an end cap (6) and an electrically conductive ring (2), wherein the end cap (6) is intended to be fixed at an axial end side of a drive shaft (3) and has an annular flange portion projecting in the axial direction, the electrically conductive ring (2) is fixed in an electrically conductive manner at an inner peripheral surface of the annular flange portion of the end cap (6), and the electrically conductive ring (2) can be fixed with its inner peripheral surface at an outer peripheral surface of the drive shaft (3) by means of an interference fit. The shaft box device comprises the aforementioned end cap assembly and a rolling bearing intended to be fitted on the drive shaft (3).

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of bogies. The present invention particularly relates to a axle box arrangement for a bogie. BACKGROUND

[0002] A bogie of a train typically comprises components such as a frame, wheelsets and axle box arrangements. The axle box arrangement serves to couple the wheelset and the bogie frame.

[0003] In an axle box arrangement for a bogie of a train, an axle box housing and a rolling bearing are provided, the rolling bearing comprising an outer ring fixed to the axle box housing and an inner ring fixed to the wheel axle. The axle box arrangement further comprises an end cap screwed to the wheel axle, which holds the rolling bearing at its predetermined axial position on the one axial side of the rolling bearing.

[0004] For example, in patent document CN 102859217 B, a bearing arrangement for a wheel axle of a railway vehicle is disclosed, which comprises a rolling bearing and an end cap, wherein the end cap is fixed to the wheel axle by means of a screw member fastened on the front end face of the wheel axle, and an annular flange portion of the end cap surrounds the axial end portion of the wheel axle and is abutted against the inner ring of the rolling bearing by means of an intermediate member. For another example, in patent document CN 102951170 B, an axle box for a railway vehicle is disclosed, which comprises a rolling bearing and an end cap, wherein the end cap has an annular raised portion defined by two cylindrical surfaces, which is inserted into an annular groove formed by the wheel axle and the inner ring of the rolling bearing. In the above-mentioned solutions, the annular flange portion or the annular raised portion of the end cap is in clearance fit with the end portion section of the wheel axle.

[0005] Furthermore, the end cap can be connected with a grounding device for the bogie, so that the electric charge at the grounding device can be transmitted to the wheel axle through the end cap, and then to the track via the wheel. However, in the axle box arrangement according to the prior art, the electric erosion phenomenon occurs in the area of the end portion of the wheel axle, especially in contact with the annular flange portion or the annular raised portion of the end cap. SUMMARY

[0006] Therefore, the purpose of the present invention is to provide an axle box arrangement, especially for a bogie, which can avoid or reduce the electric erosion problem at the end portion of the wheel axle.

[0007] The above-mentioned purpose is achieved in one aspect by an end cap assembly for an axle box arrangement, provided herein. The end cap assembly provided herein can be used in an axle box arrangement, in particular, and comprises an end cap and an electrically conductive ring, wherein the end cap is used to be fixed at the axial end side of the transmission shaft and has an annular flange portion protruding in the axial direction, wherein the electrically conductive ring is fixed in an electrically conductive manner at the inner circumferential surface of the annular flange portion of the end cap, and the electrically conductive ring can be fixed at the outer circumferential surface of the transmission shaft with its inner circumferential surface by means of an interference fit.

[0008] Here, the conductive ring is arranged concentrically with the annular flange of the end cap. When the axle box assembly is installed on the drive shaft, such as a wheel axle, the central axis of the end cap assembly, i.e., the common central axis of the conductive ring and the annular flange of the end cap, coincides with the rotation axis of the drive shaft.

[0009] Within the scope of this document, unless otherwise stated, the terms “axial,” “radial,” and “circumferential” are defined with reference to the central axis of the end cap assembly.

[0010] The conductive ring is constructed as a ring with electrical conductivity. Preferably, the conductive ring has a cylindrical outer circumferential surface. Preferably, the conductive ring has a cylindrical inner circumferential surface. This facilitates the stable radial fixing of the conductive ring between the annular flange of the end cap and the drive shaft. Both the end cap and the drive shaft are made of a conductive material, such as metal.

[0011] In a preferred embodiment, the conductive ring can be fixed to the inner circumferential surface of the annular flange of the end cap by an interference fit with its outer circumferential surface, thereby facilitating the replacement of the conductive ring when disassembling the end cap assembly.

[0012] Alternatively, the conductive ring can be fixed to the inner circumferential surface of the annular flange of the end cap by means of welding or conductive adhesive.

[0013] In a preferred embodiment, the conductive ring is made of metal. Particularly preferably, the conductive ring is made of a metal that has lower hardness and higher conductivity than the materials of the end cap and the drive shaft. For example, the conductive ring is made of copper.

[0014] Alternatively, the conductive ring can also be made of a conductive polymer material.

[0015] In one advantageous embodiment, the end cap has a connecting portion for connection with the axial end face of the drive shaft.

[0016] Particularly advantageously, the connection is constructed as bolt holes. In this case, the axle box assembly also includes bolts for fastening the end cover to the end face of the drive shaft. This allows for reliable positioning of the end cover, particularly along the axial and radial directions.

[0017] The aforementioned objective is achieved, in another respect, by a shaft housing assembly. The shaft housing assembly includes an end cap assembly according to the above embodiment and a rolling bearing for mounting on the drive shaft.

[0018] Preferably, the axle box assembly includes an axle box housing. An end cap assembly may be a component of the axle box housing. The end cap assembly particularly encloses the drive shaft, preferably an axle, on one axial side.

[0019] The rolling bearing is preferably configured as a bearing suitable for axle box assembly of a bogie, such as a double-row tapered roller bearing or a double-row cylindrical roller bearing. Here, the rolling bearing is preferably housed in an axle box housing. The rolling bearing includes an inner ring fixed to a drive shaft, such as a wheel axle, and an outer ring mounted in a bearing housing, such as the axle box housing. Here, the components of the rolling bearing, especially the inner ring, can be positioned on one axial side by means of an end cap assembly. Furthermore, advantageously, the rolling bearing is provided with a lubricant, wherein the lubricant is, for example, grease or lubricating oil.

[0020] In an alternative embodiment, the axle box assembly further includes a sealing member. The sealing member is preferably constructed at the axial outer end of the rolling bearing to prevent lubricant filling the annular internal space of the rolling bearing from leaking out and to prevent dirt and other contaminants from entering the annular internal space. Advantageously, the sealing member is constructed as an annular sealing cover arranged concentrically with the rolling bearing. The sealing cover is preferably a metal component, particularly steel. The sealing member, such as the sealing cover, is preferably mounted on the outer ring of the rolling bearing by means of an interference fit.

[0021] In one alternative embodiment, the axle box assembly further includes a sensing element. The sensing element is, for example, configured as a sensing ring for measuring rotational speed or rotational angle.

[0022] By utilizing the end cap assembly and axle box assembly provided herein, a tight connection can be established between the annular flange of the end cap and the drive shaft, particularly the wheel axle, using a conductive ring. This creates a reliable current path, facilitating timely discharge of charge and preventing charge accumulation. Furthermore, the method of fixing the conductive ring reduces or even eliminates the formation of a lubricant-based oil film between the end cap and the conductive ring, and between the conductive ring and the drive shaft, thereby minimizing the risk of electrolytic corrosion caused by sparks from the oil film.

[0023] Especially in the preferred embodiment where the conductive ring is made of copper, copper has a higher conductivity than steel, particularly cast steel, used for constructing the end cap and drive shaft. This allows for more timely conduction of charge from the end cap to the drive shaft, facilitating more efficient grounding. Furthermore, due to copper's lower hardness, the conductive ring can be easily clamped between the end cap and drive shaft during installation, for example, through an interference fit. This displaces any lubricant that may be present on the outer circumference of the axial end of the drive shaft, preventing oil film formation and thus avoiding electrolytic corrosion, particularly at the axial end of the drive shaft. Additionally, when maintenance or repair is required, the end cap can be easily removed without causing excessive wear on the drive shaft and end cap. Attached Figure Description

[0024] Preferred embodiments of the present invention will now be illustrated schematically with reference to the accompanying drawings. The drawings are as follows:

[0025] Figure 1This is an axial sectional view of a shaft box assembly according to a preferred embodiment. Detailed Implementation

[0026] Figure 1 An axial sectional view of an axle box assembly according to a preferred embodiment is shown. In this embodiment, the axle box assembly is used for a train bogie and is mounted on the axial end of axle 3.

[0027] like Figure 1 As shown, the axle box assembly includes an end cover assembly, a rolling bearing 1, a sealing component 7, and a sensing component 8 arranged coaxially.

[0028] In this embodiment, the rolling bearing 1 is constructed as a double-row tapered roller bearing. Specifically, the rolling bearing 1 includes an inner ring fixed to the axle 3 and an outer ring installed inside the axle housing (not shown).

[0029] In this embodiment, the sealing member 7 is arranged at the axial end of the rolling bearing 1 on the free end side of the axle 3 to prevent the grease filling the annular internal space of the rolling bearing 1 from leaking out and to prevent dust and other contaminants from entering the annular internal space. The sealing member is constructed as a sealing cover 7 fixed to the outer ring of the rolling bearing 1 by an interference fit. The sealing cover 7 is a steel stamping and is integrally annular.

[0030] In this embodiment, the sensing element 8 is configured as a sensing ring for measuring rotational speed or rotational angle. The sensing ring 8 is also arranged at the axial end of the rolling bearing 1 on the free end side of the axle 3.

[0031] The end cap assembly includes an end cap 6 and a conductive ring 2. The end cap 6 is integrally constructed as a disc-shaped cover and has an axially extending annular flange. The end cap 6 is fixed to the axial end face of the axle 3 by bolts 4. The end cap 6 here axially stops the rolling bearing 1, particularly the inner ring. In this embodiment, the conductive ring 2 is constructed as a copper ring, which is fixed to the inner circumferential surface of the annular flange of the end cap 6 by an interference fit with its cylindrical outer circumferential surface, and is fixed to the outer circumferential surface of the end of the axle 3 by an interference fit with its cylindrical inner circumferential surface.

[0032] Figure 1 A grounding component 5 for the bogie is also shown, which in this embodiment can be mounted on the outer peripheral surface of the end cap 6 via an interference fit. Thus, the charge transferred to the end cap 6 via the grounding component 5 can be... Figure 1 As shown by the arrow, the oil is promptly transmitted to the axle 3 via the copper ring 2, which has high conductivity. Here, in particular, it is difficult for an oil film to form between the copper ring 2 and the axle 3, thus helping to avoid electrolytic corrosion at the end of the axle 3.

[0033] While possible embodiments have been described exemplarily in the foregoing description, it should be understood that numerous variations of embodiments exist through combinations of all known and readily conceived technical features and implementation methods. Furthermore, it should be understood that the exemplary embodiments are merely examples and do not in any way limit the scope, application, or construction of the invention. The foregoing description is more intended to provide those skilled in the art with technical guidance for transforming at least one exemplary embodiment, wherein various changes can be made, particularly regarding the function and structure of the components, without departing from the scope of the claims.

[0034] List of reference signs

[0035] 1 Rolling bearing

[0036] 2. Conductive ring

[0037] 3. Drive shaft, wheel axle

[0038] 4 bolts

[0039] 5. Grounding components

[0040] 6 End Caps

[0041] 7. Sealing components, sealing covers

[0042] 8. Sensing components, sensing ring

Claims

1. An end cap assembly for an axle box assembly, the end cap assembly comprising: End cap (6), which is used to fix to the axial end side of the drive shaft (3) and has an annular flange that protrudes axially. The end cap assembly is characterized in that it further includes: A conductive ring (2) can be constructed between the annular flange of the end cap (6) fixed at the axial end of the drive shaft (3) and the drive shaft (3). The conductive ring (2) is constructed as a ring with conductive capability. The conductive ring (2) has a cylindrical outer circumferential surface and an inner circumferential surface. The conductive ring (2) is fixed in a conductive manner at the inner circumferential surface of the annular flange of the end cap (6). The conductive ring (2) can be fixed at the outer circumferential surface of the drive shaft (3) by interference fit with its inner circumferential surface, so as to establish a reliable current path between the end cap (6) fixed at the axial end of the drive shaft (3) and the drive shaft (3).

2. The end cap assembly according to claim 1, wherein, The conductive ring (2) can be fixed to the inner circumferential surface of the annular flange of the end cap (6) by interference fit with its outer circumferential surface.

3. The end cap assembly according to claim 1 or 2, wherein, The conductive ring (2) is made of metal.

4. The end cap assembly according to claim 3, wherein, The conductive ring (2) is made of copper.

5. The end cap assembly according to claim 1, wherein, The end cap (6) has a connecting portion for connecting with the axial end face of the drive shaft (3).

6. The end cap assembly according to claim 5, wherein, The connecting part is constructed as bolt holes.

7. A shaft box assembly comprising an end cap assembly according to any one of claims 1 to 6 and a rolling bearing for mounting on the drive shaft (3).

8. The axle box device according to claim 7, wherein, The axle box assembly also includes a sealing component (7).

9. The axle box device according to claim 7, wherein, The axle box device also includes a sensing component (8).

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