A new sealing method for the pick arm of a tamping device

Abstract

The present invention relates to the technical field of seals, in particular to a novel sealing method for the pick arm of a tamping device, which includes a box body, a pick arm copper sleeve and a pressure-bearing disc. The pick arm copper sleeve and the pressure-bearing disc are installed on the outer side of the box body, and a skeleton oil seal is installed on the inner side of the pressure-bearing disc. The novel sealing method for the pick arm of a tamping device in the present invention adopts a radial seal with an inner package of a skeleton with a secondary lip, which is installed between relatively rotating mechanical parts and has the function of separating the oil or grease inside from the dirt, dust, water, etc. outside. By utilizing the excellent sealing performance of the skeleton oil seal and its dust-proof lip, the influence of dust on the seal during tamping operations can be prevented, effectively protecting the stability of the lubrication system. The end faces of the two bosses connected to the cross beam of the box body by welding are each machined off by 5 mm compared with the original sealing method. Their thickness is sufficient, and the load-bearing capacity of the cross beam is not affected after machining, ensuring that there is enough installation space for the skeleton oil seal.

Description

Technical Field

[0001] The present invention relates to the technical field of seals, and in particular to a novel sealing method for the pick arm of a tamping device. Background Art

[0002] A tamping car is mainly used to tamp the ballast under the sleepers on both sides of the rail, improve the compactness of the ballast under the sleepers, and cooperate with the lifting and lining device to eliminate the unevenness of the track and enhance the stability of the track. As the main working device of the tamping car - the tamping device, during operation, it transmits vibration to the ballast through the pick arm, and at the same time, the reaction force of the ballast bed acts on the pick arm when the tamping device is inserted downward. When the tamping device is under construction, the vibration frequency reaches 35 Hz and it has to withstand huge impacts. Therefore, thin oil is used for lubrication and cooling at the connection part between the pick arm and the tamping device box body. The sealing form adopted by this structure is axial sealing. Due to reasons such as poor sealing performance and high requirements for the machining accuracy of the sealing surface, oil leakage inevitably occurs during use, affecting the normal use of the tamping device.

[0003] The traditional structural sealing method mainly has the following disadvantages: 1. This structural sealing method has very high requirements for the roughness of the area on the pressure-bearing disc that contacts the sealing ring to play a sealing role. Due to the structural reasons of the pressure-bearing disc, it is very difficult to adopt grinding machining in this area and can only rely on turning machining, so the roughness is difficult to be continuously and effectively guaranteed. Moreover, due to the lack of dust-proof design in this structure, oil leakage of the pick arm has become an inertial quality problem that has long existed during the use of the tamping device; 2. The sealing parts involved in this sealing method are axial sealing rings, which are more complex in structure than general sealing parts, and currently only imported parts are available for use. Seriously restricted by various factors at the supply end, the procurement cycle is long, and the selling price is several times higher than that of general sealing parts; 3. This sealing ring uses a spring piece to generate axial elastic force to press the sealing lip against the pressure-bearing disc. During installation, it is necessary to apply a pressure opposite to this elastic force to press the pressure-bearing disc against the sealing ring to carry out the installation. The process is relatively difficult, and there is a possibility of turning over the sealing surface of the sealing ring, resulting in sealing failure. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: to provide an improved novel sealing method for the pick arm of a tamping device to solve the problems existing in the above-mentioned background art.

[0005] The technical solution adopted by the present invention to solve its technical problems is as follows: A new sealing method for the pick arm of a tamping device, including a pick arm, a box body, a pick arm copper bushing, and a pressure-bearing disc. The pick arm copper bushing and the pressure-bearing disc are installed between the pick arm and the box body. A skeleton oil seal is installed inside the pressure-bearing disc. A spacer ring is added between the pick arm copper bushing and the skeleton oil seal. The outer circle of the spacer ring fits with the lip of the skeleton oil seal, and the inner hole of the spacer ring fits with the pick arm copper bushing installed in the crossbeam hole of the box body. The spacer ring is installed on the pick arm copper bushing through a stepped hole and is press-fitted onto the box body together with the pick arm copper bushing. After applying sealant to the stepped hole of the spacer ring, it is press-fitted onto the pick arm copper bushing to form a combination. After applying sealant to the outer circle of the pick arm copper bushing, the combination is pressed into the crossbeam hole of the tamping device box body by a hydraulic press, and a pick arm pin sleeve is inserted and reserved. The dust-proof lip on the skeleton oil seal is installed outward into the pressure-bearing disc and buckled onto the spacer ring. After positioning the pressure-bearing disc using a tooling sleeve, the subsequent installation of the pick arm and the pick arm pin is completed.

[0006] The overall spacer ring adopts a carburizing and quenching process and is machined by outer circle grinding.

[0007] Two bosses are fixed on the crossbeam of the box body, and the end faces of the bosses are each machined off by 5 mm compared with the original sealing method.

[0008] The boss is fixedly assembled with the crossbeam of the box body by welding.

[0009] The requirement for the roughness of the mating surface between the pressure-bearing disc and the skeleton oil seal only needs to reach Ra3.2.

[0010] The skeleton oil seal is composed of a sealing body with a metal skeleton inside, an arc-shaped spring groove opened on the bottom surface inside the sealing body, a hoop spring inserted inside the arc-shaped spring groove, a diaphragm fixed at the lower end of the sealing body, a sealing lip located on one side of the lower end of the diaphragm, a dust-proof lip located on the other side of the lower end of the diaphragm, and a spring retaining lip fixed on one side of the opening of the arc-shaped spring groove.

[0011] The beneficial effects of the present invention are as follows:

[0012] (1) The new sealing method for the pick arm of the tamping device of the present invention adopts a radial seal with an inner-packed skeleton and a secondary lip, which is installed between relatively rotating mechanical parts and has the function of separating the oil or grease inside from the dirt, dust, water, etc. outside. Utilizing the excellent sealing performance of the skeleton oil seal and its dust-proof lip can prevent the influence of dust on the seal during tamping operations, effectively protecting the stability of the lubrication system.

[0013] (2) The end faces of the two bosses of the box body are each machined off by 5 mm and are connected to the box body crossbeam by welding. Its thickness is sufficient, and there is no influence on the load-bearing capacity of the crossbeam after machining, ensuring that there is enough installation space for the skeleton oil seal.

[0014] (3) The pressure-bearing disc has been optimized in overall dimensions according to the relevant dimensions of the newly selected skeleton oil seal. This pressure-bearing disc only serves to install and support the skeleton oil seal, and the roughness of the mating surface with the skeleton oil seal only needs to reach Ra3.2, resulting in a significant reduction in processing difficulty and an improvement in processing economy.

[0015] (4) Since there is no relative movement between the skeleton oil seal and the pressure-bearing disc and no wear will occur, theoretically, the pressure-bearing disc does not need to be replaced during the subsequent major overhaul of the tamping device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below in conjunction with the drawings and embodiments.

[0017] Figure 1 It is a schematic structural diagram of a new sealing method for the pick arm provided by an embodiment of the present invention.

[0018] Figure 2 It is a schematic diagram of the existing structural sealing method.

[0019] Figure 3 It is a schematic diagram of the skeleton oil seal provided by an embodiment of the present invention.

[0020] Figure 4 It is a schematic design diagram of the box body provided by an embodiment of the present invention.

[0021] Figure 5 It is a schematic diagram of the spacer ring provided by an embodiment of the present invention.

[0022] Figure 6 It is a schematic diagram of the pick arm copper bushing provided by an embodiment of the present invention.

[0023] Figure 7 It is a schematic diagram of the pressure-bearing disc provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The present invention will now be further described in detail with reference to the drawings. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present invention in a schematic manner, and therefore only showing the components related to the present invention.

[0025] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] Figure 1 、 Figure 3 、 Figure 4 、Figure 5 and Figure 6 A new sealing method for the pick arm of a tamping device shown as follows, including pick arm 1, box body 7, pick arm copper sleeve 2 and pressure-bearing disc 3. The pick arm copper sleeve 2 and the pressure-bearing disc 3 are installed between the pick arm 1 and the box body 7. A skeleton oil seal 4 is installed inside the pressure-bearing disc 3. A spacer ring 5 is added between the pick arm copper sleeve 2 and the skeleton oil seal 4. The outer circle of the spacer ring 5 fits with the lip of the skeleton oil seal 4, and the inner hole of the spacer ring 5 fits with the pick arm copper sleeve 2 installed in the crossbeam hole of the box body 1. The spacer ring 5 is installed on the pick arm copper sleeve 2 through a stepped hole and is pressed onto the box body 1 together with the pick arm copper sleeve 2. After applying sealant in the stepped hole of the spacer ring 5, it is pressed onto the pick arm copper sleeve 2 to form a combination. After applying sealant on the outer circle of the pick arm copper sleeve 2, the combination is pressed into the crossbeam hole of the tamping device box body through a hydraulic press, and a pick arm pin sleeve is inserted for standby. The dust-proof lip on the skeleton oil seal 4 is installed outward into the pressure-bearing disc 3 and buckled onto the spacer ring 5. After positioning the pressure-bearing disc 3 with a tooling sleeve, the subsequent installation of the pick arm and the pick arm pin is completed.

[0027] The skeleton oil seal 4 is composed of a sealing body 41 with a metal skeleton 6 inside, an arc-shaped spring groove 42 opened on the inner bottom surface of the sealing body 41, a hoop spring 43 inserted inside the arc-shaped spring groove 42, a diaphragm 44 fixed at the lower end of the sealing body 41, a sealing lip 45 located on one side of the lower end of the diaphragm 44, a dust-proof lip 46 located on the other side of the lower end of the diaphragm 44, and a spring retaining lip 47 fixed on one side of the opening of the arc-shaped spring groove 42.

[0028] In order to improve the wear resistance and surface roughness of the sealing surface, the whole spacer ring 5 adopts a carburizing and quenching process and is processed by outer circle grinding.

[0029] Two bosses are welded and fixed on the crossbeam of the box body 7. Compared with the original sealing scheme, 5 mm is machined off each end face of the bosses. Since the two bosses are connected to the crossbeam of the box body 7 by welding, their thickness is sufficient and the load-bearing capacity of the crossbeam is not affected after machining. The processing difficulty of the box body 7 involved in the new scheme remains unchanged.

[0030] The surfaces of the housing 7 were initially all rough surfaces. In the original sealing method, machining was required at all mating locations. Now, the 5 mm to be machined means that, based on the fact that the bosses in the original sealing structure have been machined to the correct position, an additional 5 mm is removed. In the original rough housing 7, it was impossible to accurately determine the machining allowance for the sealing bosses because the dimensions of the rough surfaces were inaccurate, and due to factors such as material borrowing, the machining allowance was uncertain. Only after machining was completed was it ensured that the distance between the end faces of the two bosses was a fixed value L0. Now, based on this, the new sealing method involves modifying the original sealing structure by machining 5 mm inward from each of the end faces of the two bosses (since at this time, the end faces of the two bosses have been machined by mechanical means and are surfaces with precise positions and dimensions, so the machining allowance can be accurately determined to be 5 mm). After machining 5 mm from each of the end faces of the two bosses, the distance between the end faces of the two bosses becomes L1 = L0 - 10 mm. At this time, the space at this location can exactly accommodate the skeleton oil seal.

[0031] The case is a modification based on the original sealing method. Therefore, the distance between the set end faces of the bosses has already been machined to L0 according to the requirements of the original sealing method. The new sealing method only requires machining 5 mm from each of the end faces of the two bosses on this basis.

[0032] If the designed housing in the case is a newly fabricated rough housing, then the description of machining a certain number of millimeters from each side of the end face of the boss cannot be used. Instead, it is necessary to ensure that the final distance between the end faces of the two bosses is L1, and they are symmetrically arranged with respect to the central position at this location.

[0033] As Figure 2 shown, the surface roughness at the mating location between the pressure-bearing mechanism 31 and the seal 32 in the existing sealing structure needs to reach Ra0.8. This roughness directly affects the sealing effect, and this surface is machined using a precision turning process, which is relatively difficult. In the new solution, the pressure-bearing plate 3 has been optimized in terms of its overall dimensions according to the relevant dimensions of the newly selected skeleton oil seal 4. This pressure-bearing plate 3 only serves to install and support the skeleton oil seal 4, and the surface roughness of its mating surface with the skeleton oil seal 4 only needs to reach Ra3.2, resulting in a significant reduction in machining difficulty and an improvement in machining economy. Moreover, since there is no relative movement between the skeleton oil seal 4 and the pressure-bearing plate 3, no wear will occur. Therefore, in the subsequent major overhaul process of the ramming device using the new sealing solution, the pressure-bearing plate theoretically does not need to be replaced.

[0034] The beneficial effects of the present invention are as follows: A new sealing method for the pick arm of a tamping device in the present invention adopts a radial seal with an inner skeleton and an auxiliary lip, which is installed between relatively rotating mechanical parts and has the function of separating the oil or grease inside from the dirt, dust, water, etc. outside. By utilizing the excellent sealing performance of the skeleton oil seal 4 and its dust-proof lip, it can prevent the influence of dust on the seal during tamping operations, effectively protecting the stability of the lubrication system. The two boss end faces of the box body 1 are each machined by 5 mm and connected to the box beam by welding. Its thickness is sufficient and has no impact on the load-bearing capacity of the beam after machining, ensuring that there is enough installation space for the skeleton oil seal 4. The pressure-bearing plate 3 is optimized in its overall dimensions according to the relevant dimensions of the newly selected skeleton oil seal 4. The pressure-bearing plate 3 only serves to install and support the skeleton oil seal 4, and the surface roughness of the mating surface with the skeleton oil seal 4 reaching Ra3.2 is sufficient, greatly reducing the processing difficulty and improving the processing economy. Since there is no relative movement between the skeleton oil seal 4 and the pressure-bearing plate 3 and no wear will occur, theoretically, the pressure-bearing plate 3 does not need to be replaced during the subsequent major overhaul of the tamping device.

[0035] Enlightened by the ideal embodiments of the present invention described above, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A new sealing method for the pick arm of a tamping device, comprising a pick arm (1), a box body (7), a pick arm copper sleeve (2), and a pressure-bearing disc (3), characterized in that: The pick arm copper bushing (2) and the pressure bearing disc (3) are installed between the pick arm (1) and the box body (7). A skeleton oil seal (4) is installed inside the pressure bearing disc (3). A spacer ring (5) is added between the pick arm copper bushing (2) and the skeleton oil seal (4). The outer circle of the spacer ring (5) is fitted with the lip of the skeleton oil seal (4), and the inner hole of the spacer ring (5) is fitted with the pick arm copper bushing (2) installed in the crossbeam hole of the box body (7). The spacer ring (5) is installed on the pick arm copper bushing (2) through a stepped hole and is press-fitted onto the box body (7) together with the pick arm copper bushing (2). After applying sealant to the stepped hole of the spacer ring (5), it is press-fitted onto the pick arm copper bushing (2) to form an assembly. After applying sealant to the outer circle of the pick arm copper bushing (2), the assembly is pressed into the crossbeam hole of the tamping device box body (7) by a hydraulic press, and a pick arm pin sleeve is inserted for standby. The dust-proof lip on the skeleton oil seal (4) is installed outward into the pressure bearing disc (3) and is clamped onto the spacer ring (5). After positioning the pressure bearing disc (3) using a tooling sleeve, the subsequent installation of the pick arm and the pick arm pin is completed; Two bosses are fixed on the crossbeam of the box body (7), and 5 mm is machined off the end face of each boss compared with the original sealing method; The requirement for the surface roughness of the mating surface between the pressure bearing disc (3) and the skeleton oil seal (4) only needs to reach Ra3.

2.

2. A novel sealing method for the pick arm of a tamping device according to claim 1, characterized in that: The whole of the spacer ring (5) adopts a carburizing and quenching process and is machined by outer circle grinding.

3. A novel sealing method for the pick arm of a tamping device according to claim 1, characterized in that: The boss is fixedly assembled with the crossbeam of the box body (7) by welding.

4. A novel sealing method for the pick arm of a tamping device according to claim 1, characterized in that: The skeleton oil seal (4) consists of a sealing body (41) with a metal skeleton (6) inside, an arc-shaped spring groove (42) opened on the inner bottom surface of the sealing body (41), a hoop spring (43) inserted inside the arc-shaped spring groove (42), a diaphragm (44) fixed at the lower end of the sealing body (41), a sealing lip (45) located on one side of the lower end of the diaphragm (44), a dust-proof lip (46) located on the other side of the lower end of the diaphragm (44), and a spring retaining lip (47) fixed on one side of the opening of the arc-shaped spring groove (42).

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