Train wheelset oil injection dismounting method, device and system

Abstract

A train wheel pair oil injection dismounting method, device and system, relate to railway locomotive equipment field, the method includes: S1 clamping wheel pair and injecting high pressure oil;S2 drive wheel pair rotation with target rotation torque and detect rotation state;S3 if no relative rotation trend is generated, then stepwise increase oil injection pressure until relative rotation trend is detected, determine that oil film is initially formed;S4 stop rotation and keep pressure to establish stable oil film;S5 after releasing clamping, apply lateral dismounting thrust in dynamic loading mode.The device includes base, gantry, support column, dismounting plate, clamping mechanism, hydraulic station and controller, and is provided with oil injection pressure sensor, torque sensor, thrust sensor, angle sensor and displacement sensor.The system includes controller with computer program stored therein.The present application effectively avoids matching surface scratch, reduces axle scrap rate, and realizes full automatic closed loop control of dismounting process by first establishing stable high pressure oil film and then applying dismounting thrust.

Description

Technical Field

[0001] This invention relates to the field of railway locomotive equipment, and in particular to a method, equipment and system for oiling and unloading train wheelsets. Background Technology

[0002] In existing technologies, train wheelsets and axles are typically connected using an interference fit (press fitting). During maintenance, the wheelsets need to be removed from the axles. Traditional methods include non-oil-injected removal and oil-injected removal. Non-oil-injected removal suffers from extremely high radial contact pressure (typically reaching hundreds of megapascals) due to the interference fit. Furthermore, after long-term service, the mating surfaces exhibit microscopic adhesion, oxidation, corrosion, and fretting wear. When directly removing the wheelsets using hydraulic jacking or impact, the mating surfaces are in a state of dry friction or boundary lubrication, resulting in a high and highly unstable coefficient of friction. During removal, the mating surfaces are prone to large-area plough-grooving scratches, metal adhesion transfer, and even localized sintering, causing the axle journal dimensions to deviate or surface crack sources. In contrast, oil-injected removal involves injecting high-pressure oil into the mating interface between the wheelset and the axle. The oil pressure expands the wheelset bore wall and partially offsets the interference stress, thereby significantly reducing the removal resistance.

[0003] Existing Chinese patent CN201510783046.X discloses a wheel retraction device for axle box-integrated elastic wheelset. It uses multiple connecting bolts with diameters matching the mounting holes of the brake disc and gearbox on the axle box-integrated elastic wheelset of a new type of high-speed train as a transmission structure for the tensile retraction reaction force. A hydraulic piston and protective pad are used to apply compressive thrust axially to the end face of the axle of the new high-speed train. This innovatively changes the traditional retraction method, which directly applies retraction pressure to the inner end face of the elastic wheel rim and pushes the elastic wheel towards the outer end of the axle, to an outward pulling method from the wheel core end face. This effectively avoids directly applying retraction stress to the elastic wheel rim and prevents the squeezing and damage of flexible components such as rubber noise reduction rings and buckles. Although this application also discloses a method of injecting oil into the interference contact surface of the axle and wheelset for auxiliary retraction, in practice, due to uneven wear of the mating surfaces, oil circuit blockage, or leakage, reaching the pressure standard does not necessarily mean that the high-pressure oil has been evenly spread and formed a complete oil film on the circumferential contact surface. If a retraction thrust is blindly applied when there are local defects or insufficient thickness in the oil film, the metal substrate will still be in direct contact in the local area, and cutting-type scratches will inevitably occur under the action of the thrust. Summary of the Invention

[0004] To solve the above problems, the present invention adopts the following technical solution: A method for removing oil from train wheelsets includes the following steps: S1: Use a clamping mechanism to clamp any wheelset to be removed, and inject high-pressure oil into the circumferential contact surface between the wheelset and the axle through the oil inlet of the wheelset; S2: Drive the clamping mechanism with a preset target rotational torque to rotate the wheelset relative to the axle, and detect the actual rotation state of the wheelset in real time; S3: If the wheelset does not exhibit a relative rotational tendency under the target rotational torque, the oil injection pressure is increased and the target rotational torque is maintained at the increased oil injection pressure for a first preset duration until a relative rotational tendency of the wheelset is detected, at which point it is determined that an oil film has been initially formed. S4: In response to the initial formation of the oil film, stop the rotation and control the oil injection pressure to maintain, so that the high-pressure oil fully fills the circumferential contact surface and maintains a stable oil film state. S5: Once the stable oil film state is established, release the clamping mechanism from the wheelset, start the second motor to drive the lead screw to rotate, and move the unloading plate along the axial direction of the lead screw, thereby applying a lateral unloading thrust to the wheelset. The lateral unloading thrust is applied in a dynamic loading manner. In the initial stage, the controller dynamically adjusts the speed of the second motor according to the value collected by the thrust sensor, so that the lateral unloading thrust is applied at the first loading slope. When the axial displacement of the wheelset is detected, the current lateral unloading thrust is maintained until the unloading is completed.

[0005] Preferably, in step S5, the axial displacement of the wheelset is also collected simultaneously. When the axial displacement reaches 90% of the total unloading stroke, the loading rate of the lateral unloading thrust is reduced to 20% of the original rate, and the final unloading is completed in constant pressure and speed mode. In constant pressure and speed mode, the controller adjusts the speed of the second motor according to the feedback of the thrust sensor to maintain a constant lateral unloading thrust.

[0006] Preferably, before the oil film is initially formed, it is prohibited to apply the lateral unloading thrust to the wheelset, and it is prohibited to drive the wheelset to rotate continuously with a torque exceeding the target rotational torque.

[0007] Preferably, in S3, the increase in oil injection pressure is a step-by-step increase, with each step increment being 5-15 MPa, and the first preset duration being 1-3 seconds; the threshold for determining the relative rotation trend is: the cumulative angular displacement of the wheelset relative to the axle is greater than 0.3° and the instantaneous angular velocity is greater than 0.01° / s.

[0008] Preferably, in step S4, the oil injection pressure is controlled to be maintained at the oil injection pressure value when the oil film is initially formed, and this pressure is maintained within a preset pressure holding time. The preset pressure holding time is determined according to the wheelset model and has a value range of 5-30 seconds. If the oil injection pressure drop value is detected to exceed a preset threshold within the preset pressure holding time, the hydraulic station is activated to replenish the pressure and restore the oil injection pressure to the pressure value when the oil film is initially formed.

[0009] Preferably, in S5, during the application of the lateral unloading thrust, when the actual lateral unloading thrust detected by the thrust sensor exceeds a preset safety threshold, and the displacement sensor detects that the axial displacement of the wheelset has not changed, the controller immediately controls the second motor to stop unloading to prevent the axle from being damaged due to overload.

[0010] Preferably, the present invention also provides a train wheelset oiling and unloading device, including a base and a gantry frame. The gantry frame is fixedly mounted on the base. The inner sidewall of the gantry frame has a push rod, which is used to press against the end of the axle during unloading to limit the axial movement of the axle. A set of support columns for supporting the wheelset assembly to be unloaded is also fixed on the base. An unloading plate for unloading the wheelset is also installed between the two support columns, and the top of the unloading plate is open. A clamping mechanism is slidably arranged below the top of the gantry frame. The clamping mechanism includes an arc-shaped frame. The arc-shaped inner wall of the arc-shaped frame faces the wheelset to be unloaded. An arc-shaped guide groove is opened on the inner wall of the arc-shaped frame, and a transverse guide groove is also opened through the arc-shaped frame on both sides. The arc-shaped frame is connected to the arc-shaped guide groove. An arc-shaped toothed plate is fixedly installed on one side of the arc-shaped frame. A sliding block is movably installed in the arc-shaped guide groove. Two clamping arms are slidably installed at the bottom of the sliding block. The two clamping arms are used to clamp the wheelset to be unloaded. A hydraulic station and controller are also provided on one side of the base. The hydraulic station is connected to the oil filling port of the wheelset through an oil pipe. The clamping mechanism also includes a guide shaft. The guide shaft is movably installed in the transverse guide groove and passes through the sliding block. A drive gear is fixedly installed at one end of the guide shaft and the other end is fixedly connected to the output end of the drive motor. A sliding cavity is also opened at the bottom of the sliding block. A support shaft is transversely arranged in the sliding cavity. Two clamping arms are respectively fitted on the support shaft.

[0011] Preferably, a spring is also provided between the two clamping arms, and the two inner sidewalls of the arc-shaped guide groove are also equipped with expanding plates. When the outer sides of the two clamping arms contact the corresponding expanding plates, the two clamping arms gradually approach each other radially under the guidance of the expanding plates and clamp the wheelset.

[0012] Preferably, the device of the present invention further includes an oil injection pressure sensor, disposed on the oil pipe connecting the hydraulic station and the oil injection port, for real-time acquisition of the oil injection pressure value; a torque sensor, disposed on the output shaft of the drive motor, for real-time acquisition of the actual rotational torque output by the drive motor; a thrust sensor, disposed on the unloading plate, for real-time acquisition of the lateral unloading thrust value applied by the unloading plate to the wheelset; an angle sensor, disposed on the clamping arm or the output shaft of the drive motor, for real-time acquisition of the angular displacement of the wheelset relative to the axle; and a displacement sensor, disposed on the unloading plate, for real-time acquisition of the axial displacement of the wheelset.

[0013] Preferably, the present invention also provides a train wheelset oil injection and unloading system, including a controller, the controller including a memory and a processor, the memory storing a computer program, and the computer program being executed by the processor to implement the unloading method described above.

[0014] Compared with the prior art, the beneficial effects of the present invention are at least as follows: First, this invention establishes a stable high-pressure oil film before applying unloading thrust. It uses a step-by-step pressure increase combined with rotation trend detection to accurately determine the initial formation time of the oil film. By maintaining pressure, the high-pressure oil fully fills the mating surface circumferentially to form a continuous and complete stable oil film. This effectively avoids cutting-type scratches on the mating surface caused by blindly applying unloading thrust when the oil film is partially missing or insufficient in thickness, and significantly reduces the axle scrap rate.

[0015] Secondly, the lateral unloading thrust of the present invention adopts a dynamic loading method, and achieves closed-loop control through the joint real-time feedback of the thrust sensor and the displacement sensor. Before the wheelset generates axial displacement, it is slowly loaded at a set slope. Once displacement is detected, it immediately switches to constant force maintenance mode to complete unloading with the minimum necessary thrust, avoiding impact damage to the mating surface caused by sudden thrust changes, and protecting the integrity of the axle and wheelset mating surface to the maximum extent.

[0016] Third, the clamping mechanism of the present invention utilizes the inclined guide of the expanding plate and the restoring force of the spring to achieve passive clamping and release, eliminating the need for an additional clamping drive source and simplifying the equipment structure; in conjunction with a multi-sensor system and controller, it realizes full-process automation of oil injection, clamping, rotation detection, oil film determination, pressure holding, dynamic loading and unloading, reducing the skill requirements and risk of misoperation for manual operation, and significantly improving unloading efficiency and consistency. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of the method of the present invention; Figure 2 This is a three-dimensional structural schematic diagram of the device of the present invention; Figure 3 This is a front view schematic diagram of the device of the present invention; Figure 4 This is a top view of the device of the present invention; Figure 5 for Figure 3 Schematic diagram of the cross-sectional structure along line AA; Figure 6 for Figure 3 Schematic diagram of the cross-sectional structure along line BB; Figure 7 for Figure 4 A cross-sectional view of the structure along the CC line; Figure 8 for Figure 7 A partially enlarged structural diagram of section D in the middle; Figure 9 This is a partial cross-sectional view of the device of the present invention; Figure 10 This is a schematic diagram of the system composition of the present invention; In the diagram: 1. Base; 2. Gantry frame; 3. Top rod; 4. Axle; 5. Wheelset; 6. Support column; 7. Unloading plate; 8. Clamping mechanism; 80. Arc frame; 81. Arc guide groove; 82. Transverse guide groove; 83. Arc toothed plate; 84. Sliding block; 85. Clamping arm; 86. Guide shaft; 87. Drive gear; 88. Drive motor; 9. Hydraulic station; 10. Controller; 11. Sliding cavity; 12. Support shaft; 13. Spring; 14. Expanding plate; 15. Oil injection pressure sensor; 16. Torque sensor; 17. Thrust sensor; 18. Angle sensor; 19. Displacement sensor; 20. Lead screw; 21. Second motor; 100. Memory; and 101. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0020] Example 1: This embodiment provides a method for oil injection and unloading of train wheelsets. Based on the principle of oil injection and unloading, this method avoids dry friction or boundary friction between the mating surfaces of the wheelset 5 and the axle 4 when the oil film is incomplete, thus preventing damage. Each step of this method is centrally controlled and coordinated by a controller 10. The controller 10 pre-stores process parameter packages corresponding to different wheelset 5 models, including but not limited to target rotational torque, step increment, and preset pressure holding time. The following describes the method in conjunction with the attached... Figure 1 The flowchart shown provides a detailed explanation of the specific implementation process for each step.

[0021] Please see Figures 1-10A method for removing oil from train wheelsets includes the following steps: S1: Use the clamping mechanism 8 to clamp any wheelset 5 to be removed, and inject high-pressure oil into the circumferential contact surface between the wheelset 5 and the axle 4 through the oil injection port of the wheelset 5. S2: Drive the clamping mechanism 8 with a preset target rotational torque to make the wheelset 5 rotate relative to the axle 4, and detect the actual rotation state of the wheelset 5 in real time; S3: If the wheelset 5 does not exhibit a relative rotational tendency under the target rotational torque, the oil injection pressure is increased and the target rotational torque is maintained at the increased oil injection pressure for a first preset duration until the wheelset 5 is detected to exhibit a relative rotational tendency, at which point it is determined that an oil film has been initially formed. S4: In response to the initial formation of the oil film, stop the rotation and control the oil injection pressure to maintain, so that the high-pressure oil fully fills the circumferential contact surface and maintains a stable oil film state. S5: After the stable oil film state is established, the clamping mechanism 8 is released from clamping the wheelset 5, and the second motor 21 is started to drive the lead screw 20 to rotate, so that the unloading plate 7 moves along the axial direction of the lead screw 20, thereby applying a lateral unloading thrust to the wheelset 5. The lateral unloading thrust is applied in a dynamic loading manner. In the initial stage, the controller 10 dynamically adjusts the speed of the second motor 21 according to the value collected by the thrust sensor 17, so that the lateral unloading thrust is applied with the first loading slope. When the axial displacement of the wheelset 5 is detected, the current lateral unloading thrust is maintained until the unloading is completed.

[0022] The specific steps are as follows: S1: Initially, when the outer surfaces of the two clamping arms 85 begin to contact the corresponding expanding plates 14, the gradually changing inclined structure of the expanding plates 14 applies a radially inward guiding force to the outer surfaces of the clamping arms 85, causing the two clamping arms 85 to overcome the elastic force of the springs 13 and slide towards each other along the support shaft 12. That is, the two clamping arms 85 gradually move radially closer from both sides of the wheelset 5. The process controller 10 simultaneously starts the hydraulic station 9 and begins to inject high-pressure oil into the circumferential contact surface between the wheelset 5 and the axle 4 through the oil injection port. The high-pressure oil enters the annular gap of the interference fit surface along the oil injection channel.

[0023] S2: When the outer sides of the two clamping arms 85 pass the gradually inclined surface of the expanding plate 14 and enter the smooth holding surface area of ​​the expanding plate 14, the drive motor 88 continues to output the target rotational torque. Since the clamping arms 85 have firmly clamped the wheelset 5, the rotational torque is transmitted to the wheelset 5 through the clamping arms 85, causing the wheelset 5 to tend to rotate or actually rotate relative to the axle 4.

[0024] S3: The controller 10 makes a judgment based on the feedback signal from the angle sensor 18: If, under the continuous action of the target rotational torque, the wheelset 5 does not exhibit a relative rotational tendency relative to the axle 4, i.e., the cumulative angular displacement does not exceed 0.3° and the instantaneous angular velocity does not exceed 0.01° / s, it indicates that under the current oil injection pressure, the high-pressure oil has not yet formed an effective oil film on the mating surface sufficient to reduce the static friction coefficient, and the frictional resistance between the mating surfaces is still greater than the limit that the rotational torque output by the drive motor 88 can overcome. At this time, the controller 10 controls the hydraulic station 9 to increase the oil injection pressure in a stepwise manner, with each step increment being 5 to 15 MPa. The specific step value is automatically selected by the controller 10 from the pre-stored process parameter package according to the model of the wheelset 5. After each increase in oil injection pressure, the controller 10 maintains the continuous output of the target rotational torque and holds this torque for 1 to 3 seconds (the first preset duration), during which time the feedback data of the angle sensor 18 and the torque sensor 16 are continuously monitored.

[0025] Taking a specific wheelset model 5 as an example, assuming the initial oil injection pressure is 30MPa, the controller 10 first drives the wheelset 5 to rotate at this pressure. If no relative rotation trend is detected, the hydraulic station 9 controls the oil injection pressure to increase by 5MPa to 35MPa in steps, and maintains the target rotational torque for 1 second before detecting again. If no rotation trend is detected, the pressure is further increased to 40MPa and maintained for 1.5 seconds before detecting again. This cycle continues until the cumulative angular displacement of the wheelset 5 is detected to be greater than 0.3° and the instantaneous angular velocity is greater than 0.01° / s at a certain pressure value. At this point, the controller 10 determines that the high-pressure oil has initially established an oil film sufficient to reduce the static friction coefficient in the circumferential direction of the mating surface, that is, the oil film has been initially formed.

[0026] S4: When the controller 10 determines that the oil film has initially formed based on the feedback from the angle sensor 18, the controller 10 immediately issues a command to stop the rotation of the drive motor 88, and the clamping arm 85 stops the circumferential drive of the wheel set 5. At the same time, the controller 10 controls the hydraulic station 9 to maintain the current oil injection pressure unchanged, that is, to maintain the oil injection pressure value locked when the oil film initially forms, so that the high pressure oil continues to fill and diffuse in the circumferential contact surface.

[0027] S5: After the stable oil film is established, the controller 10 controls the drive motor 88 to reverse, so that the clamping arm 85 retracts from the smooth holding surface of the expanding plate 14 to the gradually inclined area. The two clamping arms 85 automatically open under the elastic force of the spring 13, releasing the clamping of the wheelset 5. At the same time, the controller 10 controls the arc frame 80 at the top of the gantry 2 to move upward, further releasing the displacement restriction of the wheelset 5. Subsequently, the controller 10 starts the second motor 21, which drives the lead screw 20 to rotate. The lead screw 20 drives the unloading plate 7 to move along the axial direction of the axle 4 through the threaded transmission pair, applying a lateral unloading thrust to the wheelset 5.

[0028] The lateral unloading thrust is applied in a dynamic loading manner. In the initial stage, the controller 10 dynamically adjusts the speed of the second motor 21 according to the value collected by the thrust sensor 17, so that the lateral unloading thrust is applied with the first loading slope. When the axial displacement of the wheelset 5 is detected, the current lateral unloading thrust is maintained until the unloading is completed.

[0029] Specifically, the controller 10 reads the first loading slope corresponding to the current wheelset 5 model from the internally stored process parameter package. The first loading slope is pre-calibrated based on parameters such as the interference fit, mating surface width, and material properties of the wheelset 5, and its value ranges from 0.5 to 1.0 KN / s. The thrust sensor 17 is set on the unloading plate 7 and collects the lateral unloading thrust value applied by the unloading plate 7 to the wheelset 5 in real time at a sampling frequency of not less than 100Hz.

[0030] Taking a specific wheelset model 5 as an example, assume that the first loading slope is set to 0.8KN / s.

[0031] The controller 10 executes the following closed-loop control logic: First, it reads the real-time value of the thrust sensor 17 (e.g., 2.3 KN), and then calculates the target thrust value to be achieved at the current moment based on the first loading slope. For example, when the loading time is 3 seconds, the target thrust value = 0 + 0.8 × 3 = 2.4 KN. The controller 10 compares the measured thrust value with the target thrust value. If the measured value is lower than the target value, the speed of the second motor 21 is appropriately increased; if the measured value is higher than the target value, the speed of the second motor 21 is appropriately decreased. This comparison and adjustment process is continuously performed at a frequency of tens of times per second to ensure that the lateral unloading thrust always increases linearly at a slope of 0.8 KN / s. During the thrust loading process, the displacement sensor 19 synchronously monitors the axial displacement of the wheel set 5 relative to the axle 4 and transmits the data to the controller 10 in real time. The controller 10 continuously judges whether the axial displacement fed back by the displacement sensor 19 has changed. When the displacement sensor 19 detects that the axial displacement is greater than the preset displacement threshold (such as 0.5mm), the controller 10 determines that the wheel set 5 has generated axial displacement, indicating that the high-pressure oil film has successfully converted static friction into dynamic friction, and the wheel set 5 begins to slide outward along the axle 4.

[0032] At this point, the controller 10 immediately stops increasing the thrust according to the first loading slope, and instead records the thrust value currently fed back by the thrust sensor 17 (e.g., 40KN) and uses it as the target maintenance value for the subsequent constant force unloading stage. It continuously reads the real-time value of the thrust sensor 17 and compares it with the locked value of 40KN: when the measured value is lower than 40KN, the speed of the second motor 21 is increased; when the measured value is higher than 40KN, the speed of the second motor 21 is decreased, so that the thrust is always maintained within the range of 40KN±0.5KN. The wheelset 5 continues to exit outward under the action of constant thrust until the displacement sensor 19 detects that the displacement has reached the total unloading stroke value. The controller 10 determines that the unloading is completed and stops the second motor 21. This scheme avoids the impact damage to the mating surfaces caused by sudden thrust changes, completes unloading with the minimum necessary thrust, and protects the mating surfaces of axle 4 and wheelset 5 from damage to the maximum extent. The joint real-time feedback of thrust sensor 17 and displacement sensor 19 realizes closed-loop control, enabling controller 10 to capture signals and switch control modes as soon as wheelset 5 begins to move, with fast response speed and high control accuracy.

[0033] In some preferred embodiments, before the oil film initially forms, the lateral unloading thrust is prohibited from being applied to the wheelset 5, and the wheelset 5 is prohibited from being continuously rotated with a torque exceeding the target rotational torque. Through the above technical solutions, this double prohibition further ensures that the axle 4 will not be scratched or worn before the oil film initially forms.

[0034] In some preferred embodiments, in S3, the increase in oil injection pressure is a step-by-step increase, with each step increment being 5-15 MPa, and the first preset duration being 1-3 seconds; the threshold for determining the relative rotation trend is: the cumulative angular displacement of the wheelset 5 relative to the axle 4 is greater than 0.3° and the instantaneous angular velocity is greater than 0.01° / s.

[0035] Specifically: Taking a specific wheelset model 5 as an example, the controller 10 reads the initial oil injection pressure as 30MPa, the step increment as 5MPa, and the first preset duration as 1.5 seconds.

[0036] The controller 10 first controls the hydraulic station 9 to continuously inject oil into the mating surface at a pressure of 30 MPa. The oil injection pressure sensor 15 monitors the oil injection pressure value in real time at a sampling frequency of 100 Hz to ensure that the pressure is stable within the range of 30 MPa ± 0.5 MPa. At the same time, the controller 10 controls the drive motor 88 to output a target rotational torque. This target rotational torque is a preset value read by the controller 10 from the process parameter package according to the model of the wheelset 5. Its value is pre-calibrated according to parameters such as the interference fit, mating surface diameter, and friction coefficient of the wheelset 5. The controller 10 starts a timer and continuously monitors the feedback signal of the angle sensor 18 within the first preset time period (e.g., 1.5 seconds) after the target rotational torque is applied. The angle sensor 18 is set on the output shaft of the clamping arm 85 or the drive motor 88 and collects the angular displacement and instantaneous angular velocity of the wheelset 5 relative to the axle 4 in real time at a sampling frequency of not less than 100 Hz. If the angle sensor 18 detects that the cumulative angular displacement of the wheelset 5 relative to the axle 4 is greater than 0.3° and the instantaneous angular velocity is greater than 0.01° / s within 1.5 seconds, it is directly determined that the high-pressure oil has initially established an effective oil film sufficient to reduce the static friction coefficient in the circumferential direction of the mating surface, that is, the oil film has initially formed. The controller 10 locks the current oil injection pressure as the oil film initial formation pressure, records it in the memory 100 of the controller 10, and jumps to step S4.

[0037] If the aforementioned angular displacement and angular velocity conditions are not detected within 1.5 seconds, the controller 10 determines that the current injection pressure is insufficient to form an effective oil film on the mating surface, and then controls the hydraulic station 9 to increase the injection pressure stepwise by 5 MPa to 35 MPa. During the pressure increase process, the controller 10 controls the hydraulic station 9 to slowly increase the pressure at a rate not exceeding 2 MPa / s to avoid pressure surges causing impact damage to the seals. After the pressure stabilizes at 35 MPa, the controller 10 resumes maintaining the target rotational torque and starts a timer to monitor the feedback signal from the angle sensor 18 again within the second preset duration (e.g., 1.5 seconds).

[0038] Throughout the step-by-step pressurization process, the controller 10 continuously monitors the feedback from the torque sensor 16 to ensure that the output torque of the drive motor 88 does not exceed the preset safety upper limit, preventing damage to the mating surfaces due to excessive torque. Simultaneously, the controller 10 monitors the feedback from the oil injection pressure sensor 15 to ensure that the oil injection pressure does not exceed the maximum output capacity of the hydraulic station 9 (e.g., 120 MPa) and the upper limit of the seal's withstand pressure.

[0039] When the oil injection pressure rises to a certain value (e.g., 60 MPa), the angle sensor 18 detects that the cumulative angular displacement of the wheelset 5 reaches 0.35° and the instantaneous angular velocity reaches 0.015° / s. Both conditions simultaneously meet the threshold, and the controller 10 determines that the high-pressure oil has initially established an oil film sufficient to reduce the static friction coefficient in the circumferential direction of the mating surfaces, i.e., the oil film has initially formed. The controller 10 immediately locks this pressure value (60 MPa) as the initial oil film formation pressure, stops further pressure increases, stops the timer, records the actual time taken from the application of the target rotational torque at the current pressure level to the detection of a rotational trend, and stores this data in the memory 100 for subsequent analysis.

[0040] It should be noted that the "relative rotational tendency" in step S3 refers to the physical state in which wheelset 5 has not yet produced continuous rotation under the action of the target rotational torque, but has already shown a small accumulation of angular displacement and instantaneous angular velocity. This state indicates that a high-pressure oil film has begun to form in a local area of ​​the mating surface, and the oil film pressure has begun to reduce the static friction coefficient, but has not yet reached a level sufficient to make wheelset 5 rotate continuously.

[0041] The stepped pressurization method avoids sudden stress changes and seal failures on the mating surfaces that may occur when the pressure jumps directly from the initial pressure to the target pressure, thus protecting the equipment and extending its service life. The pressure holding detection method, which maintains the target rotational torque after each pressurization, allows the high-pressure oil sufficient time to flow and diffuse in the gap between the mating surfaces, making the detection results closer to the actual physical state and improving the accuracy of oil film formation determination. Furthermore, the dual judgment threshold effectively eliminates misjudgments caused by non-oil film factors such as equipment vibration and sensor noise, ensuring the reliability of the detection while avoiding insufficient oil film due to premature judgment.

[0042] In some preferred embodiments, in step S4, the oil injection pressure is controlled to be maintained at the oil injection pressure value when the oil film is initially formed, and this pressure is maintained within a preset pressure holding time. The preset pressure holding time is determined according to the wheelset model 5 and ranges from 5 to 30 seconds. If the oil injection pressure drop value is detected to exceed a preset threshold within the preset pressure holding time, the hydraulic station 9 is activated to replenish the pressure and restore the oil injection pressure to the pressure value when the oil film is initially formed.

[0043] Specifically: Controller 10 controls hydraulic station 9 to maintain the current oil injection pressure unchanged, that is, to maintain the oil injection pressure value locked when the oil film is initially formed. Controller 10 reads the preset holding time corresponding to the current wheelset model 5 from the internally stored process parameter table. The process parameter table contains mapping relationships between multiple wheelset models 5 and their corresponding holding times. This mapping relationship is obtained through calibration using previous test data. The specific calibration method is as follows: for each model of wheelset 5, unloading tests with different holding times are conducted under test conditions. The optimal holding time is determined with the goal of minimizing damage to the mating surfaces and minimizing the unloading thrust after unloading.

[0044] In some preferred embodiments, during the process of applying the lateral unloading thrust in S5, when the actual lateral unloading thrust detected by the thrust sensor 17 exceeds a preset safety threshold, and the displacement sensor 19 detects that the axial displacement of the wheelset 5 has not changed, the controller 10 immediately controls the second motor 21 to stop unloading to prevent the axle 4 from being damaged due to overload.

[0045] Example 2: See Figures 2-9 The present invention also provides a train wheelset oiling and unloading device, including a base 1 and a gantry 2. The gantry 2 is fixedly mounted on the base 1. The inner sidewall of the gantry 2 has a push rod 3, which is used to press against the end of the axle 4 during unloading to limit the axial movement of the axle 4. A set of support columns 6 for supporting the wheelset assembly to be unloaded is also fixed on the base 1. An unloading plate 7 for unloading the wheelset is also installed between the two support columns 6, and the top of the unloading plate 7 is open. A clamping mechanism 8 is slidably arranged below the top of the gantry 2. The clamping mechanism 8 includes an arc-shaped frame 80. The arc-shaped inner wall of the arc-shaped frame 80 faces the wheelset 5 to be unloaded. An arc-shaped guide groove 81 is opened on the inner wall of the arc-shaped frame 80, and a transverse guide groove 82 is also opened through the arc-shaped frame 80 on both sides. The transverse guide groove 82 is connected to the arc-shaped guide groove 81. The arc-shaped frame 80 has an arc-shaped toothed plate 83 fixedly installed on one side. A sliding block 84 is movably fitted in the arc-shaped guide groove 81. Two clamping arms 85 are slidably installed at the bottom of the sliding block 84. The two clamping arms 85 are used to clamp the wheelset 5 to be removed. A hydraulic station 9 and a controller 10 are also provided on one side of the base 1. The hydraulic station 9 is connected to the oil inlet of the wheelset 5 through an oil pipe. The clamping mechanism 8 also includes a guide shaft 86. The guide shaft 86 is movably installed in the transverse guide groove 82 and passes through the sliding block 84. A drive gear 87 is fixedly installed at one end of the guide shaft 86, and the other end is fixedly connected to the output end of the drive motor 88. A sliding cavity 11 is also opened at the bottom of the sliding block 84. A support shaft 12 is transversely arranged in the sliding cavity 11. Two clamping arms 85 are respectively fitted on the support shaft 12.

[0046] In some preferred embodiments, see Figures 8-9 A spring 13 is also provided between the two clamping arms 85, and the spring 13 is also located in the sliding cavity 11. The two inner sidewalls of the arc-shaped guide groove 81 are also fitted with expanding plates 14. When the outer sides of the two clamping arms 85 contact the corresponding expanding plates 14, the two clamping arms 85 gradually approach radially under the guidance of the expanding plates 14 and clamp the wheelset 5. The spring 13 can be used for resetting, and the expanding plates 14... Figure 6 and Figure 9As shown, the expanding plate 14 has a gradually tapered slope and a smooth retaining surface.

[0047] In some preferred embodiments, the device of the present invention further includes an oil injection pressure sensor 15, disposed on the oil pipe connecting the hydraulic station 9 and the oil injection port, for real-time acquisition of the oil injection pressure value; a torque sensor 16, disposed on the output shaft of the drive motor 88 or the guide shaft 86, for real-time acquisition of the actual rotational torque output by the drive motor 88; a thrust sensor 17, disposed on the unloading plate 7, for real-time acquisition of the lateral unloading thrust value applied by the unloading plate 7 to the wheelset 5; an angle sensor 18, disposed on the clamping arm 85 or the output shaft of the drive motor 88, for real-time acquisition of the angular displacement of the wheelset 5 relative to the axle 4; and a displacement sensor 19, disposed on the unloading plate 7, for real-time acquisition of the axial displacement of the wheelset 5.

[0048] The principle of the device of this invention is as follows: See Figures 2-9 Before starting work, the controller 10 controls the drive mechanism (such as an electric cylinder) at the top of the gantry 2 to adjust the arc frame 80 in the lateral direction to a position directly opposite the wheel set 5, based on the axial position of the wheel set 5 on the axle 4. Then, the wheel set assembly to be unloaded is placed on the two support columns 6, keeping the axle 4 horizontal. The wheel set 5 is located in the unloading area between the two support columns 6. At this time, the wheel set 5 is located between the two clamping arms 85 but has not yet been clamped. That is, the sliding block 84 is at the starting end of the arc guide groove 81, and the two clamping arms 85 are in the open state under the elastic force of the spring 13.

[0049] Subsequently, the operator connects the oil supply line of the hydraulic station 9 to the oil inlet of the wheelset 5 and completes the sealing. The controller 10 starts the hydraulic station 9 and begins to inject high-pressure oil into the circumferential contact surface between the wheelset 5 and the axle 4 through the oil inlet. At the same time as the oil is injected, the controller 10 controls the drive motor 88 to start. The output shaft of the drive motor 88 drives the guide shaft 86 to rotate. The drive gear 87 fixed at the end of the guide shaft 86 rotates accordingly. Since the drive gear 87 meshes with the arc-shaped toothed plate 83 fixed on one side of the arc-shaped frame 80, and the arc-shaped toothed plate 83 is a fixed part, the rotation of the drive gear 87 will generate relative displacement along the tooth trajectory of the arc-shaped toothed plate 83, thereby driving the guide shaft 86 and the sliding block 84 that it passes through to slide together along the arc-shaped trajectory of the arc-shaped guide groove 81.

[0050] During this process, the drive motor 88, guide shaft 86, sliding block 84, and two clamping arms 85 move synchronously along an arc-shaped trajectory as a whole. The two clamping arms 85 are located on both sides of the wheelset 5. As the sliding block 84 slides along the arc-shaped guide groove 81, the two clamping arms 85 gradually approach the outer peripheral surface of the wheelset 5 from the tangential direction of the wheelset 5. When the outer surfaces of the two clamping arms 85 begin to contact the corresponding expanding plate 14, the gradually changing inclined surface structure of the expanding plate 14 applies a radially inward (i.e., towards the axis of the wheelset 5) guiding force to the outer side of the clamping arms 85, so that the two clamping arms 85 overcome the elastic force of the spring 13 and slide towards each other along the support shaft 12. That is, the two clamping arms 85 gradually approach each other radially from both sides of the wheelset 5, and finally the ends of the clamping arms 85 clamp the spokes or rim root of the wheelset 5.

[0051] During the clamping process of the clamping arms 85 clamping the wheelset 5, oil injection continues, and high-pressure oil continuously enters the annular gap of the mating surface. After the outer sides of the two clamping arms 85 pass the gradually tapered slope of the expanding plate 14, they enter the smooth holding surface area of ​​the expanding plate 14. In this area, the radial pressure of the expanding plate 14 on the clamping arms 85 remains constant, and the two clamping arms 85 maintain a constant clamping force on the wheelset 5. At this time, the drive motor 88 continues to output rotational torque. Since the clamping arms 85 have firmly clamped the wheelset 5, this rotational torque is transmitted to the wheelset 5 through the clamping arms 85, causing the wheelset 5 to tend to rotate or actually rotate relative to the axle 4. During this stage, the controller 10 detects the actual rotational torque output by the drive motor 88 in real time through the torque sensor 16, detects the angular displacement and angular velocity of the wheelset 5 relative to the axle 4 in real time through the angle sensor 18, and detects the oil injection pressure value in real time through the oil injection pressure sensor 15. When the controller 10 determines, based on the feedback signal from the angle sensor 18, that the wheelset 5 has not rotated under the target rotational torque, it is determined that the wheelset 5 has not rotated. When there is a relative rotational trend, i.e., the cumulative angular displacement does not exceed 0.3° and the instantaneous angular velocity does not exceed 0.01° / s, the controller 10 controls the hydraulic station 9 to gradually increase the injection pressure in a stepped increment (5 to 15 MPa), and maintains the target rotational torque for 1 to 3 seconds at each pressure step, until the angle sensor 18 detects that the cumulative angular displacement of the wheelset 5 is greater than 0.3° and the instantaneous angular velocity is greater than 0.01° / s. At this time, the controller 10 determines that the oil film has initially formed. After determining that the oil film has initially formed, the controller 10 immediately stops the drive motor 88, so that the clamping arm 85 stops applying rotational torque to the wheelset 5. At the same time, the controller controls the hydraulic station 9 to maintain the current injection pressure for pressure holding, so that the high-pressure oil fully fills the circumferential direction of the mating surface and forms a continuous and complete stable oil film. During the pressure holding period, the injection pressure sensor 15 continuously monitors the pressure value. If the pressure drops beyond the preset threshold, the controller 10 automatically starts the hydraulic station 9 to replenish the pressure.

[0052] After a stable oil film is established, controller 10 controls drive motor 88 to reverse, causing clamping arms 85 to retract from the smooth holding surface of the expanding plate 14 to the gradually tapered slope area. The two clamping arms 85 automatically open under the elastic force of spring 13, releasing the clamp on wheelset 5 and causing the arc-shaped frame 80 to move upwards, releasing displacement restriction. It should be noted that the arc-shaped frame 80 also extends and retracts vertically (not shown in the attached diagram). This extension and retraction mainly adjusts the vertical distance between the arc-shaped frame 80 and wheelset 5. Subsequently, controller 10 initiates the... The second motor 21 drives the lead screw 20 to rotate. The lead screw 20 drives the unloading plate 7 to move along the axial direction of the axle 4 through the threaded transmission pair. The end face of the unloading plate 7 abuts against the end face of the wheelset 5 and moves in the unloading direction. The thrust sensor 17 monitors the lateral unloading thrust value in real time, and the displacement sensor 19 monitors the axial displacement of the wheelset 5 in real time. The controller 10 performs closed-loop control based on the feedback signals from both, and applies thrust in a dynamic loading manner until the wheelset 5 is completely removed from the axle 4.

[0053] Throughout the unloading process, the push rod 3 is always pressed against the end of the axle 4, restricting the axle 4 from moving axially along with the wheelset 5 during unloading. This ensures that the lateral unloading thrust of the unloading plate 7 during movement is used to overcome the frictional resistance between the mating surfaces of the wheelset 5 and the axle 4, allowing the wheelset 5 to smoothly exit along the axial direction of the axle 4.

[0054] This application utilizes the inclined guide of the expanding plate 14 and the restoring force of the spring 13 to achieve passive clamping and passive release that are automatically completed as the sliding block 84 slides, eliminating the need for additional clamping drive cylinders or electromagnets, simplifying the equipment structure and reducing the failure rate; the drive motor 88 continues to output rotational torque after clamping is completed, so that the oil film detection and clamping action during the oil injection process are completed by the same power source in a time-sharing manner, resulting in a compact and efficient power transmission chain; the smooth holding surface design of the expanding plate 14 ensures that the clamping force remains constant during the application of rotational torque by the clamping arm 85, avoiding loosening or skewing of the wheel set 5 due to fluctuations in clamping force; the entire control process is fully automatically executed by the controller 10 based on feedback signals from multiple sensors, realizing full automation of the oil injection, clamping, rotation detection, oil film determination, pressure holding, and unloading process, significantly reducing the skill requirements and risk of misoperation for manual operation.

[0055] See Figure 10The present invention also provides a train wheelset oil injection and unloading system, including a controller 10. The controller 10 includes a memory 100 and a processor 101. The memory 100 is a non-volatile storage medium used to store computer programs, process parameter tables, wheelset model databases, and historical unloading records, etc. The processor 101 is a central processing unit used to execute the computer program stored in the memory 100. When the computer program is executed by the processor 101, the processor 101 executes each step of the unloading method in Embodiment 1 according to the program instructions. Specifically, it includes: receiving feedback signals from each sensor, performing logical judgment and calculation based on the feedback signals, and issuing control commands to the drive motor 88, the second motor 21, and the hydraulic station 9 to realize fully automated control of oil injection, rotation detection, oil film determination, pressure holding, and unloading thrust loading. It should be understood that the processor 101 also has data recording and communication functions, which can store the process data of each unloading process in the memory 100 and upload it to the upper-level management system through the communication interface.

[0056] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for removing oil from train wheelsets, characterized in that, Includes the following steps: S1: Use a clamping mechanism to clamp any wheelset to be removed, and inject high-pressure oil into the circumferential contact surface between the wheelset and the axle through the oil inlet of the wheelset; S2: Drive the clamping mechanism with a preset target rotational torque to rotate the wheelset relative to the axle, and detect the actual rotation state of the wheelset in real time; S3: If the wheelset does not exhibit a relative rotational tendency under the target rotational torque, the oil injection pressure is increased and the target rotational torque is maintained at the increased oil injection pressure for a first preset duration until a relative rotational tendency of the wheelset is detected, at which point it is determined that an oil film has been initially formed. S4: In response to the initial formation of the oil film, stop the rotation and control the oil injection pressure to maintain, so that the high-pressure oil fully fills the circumferential contact surface and maintains a stable oil film state. S5: Once the stable oil film state is established, release the clamping mechanism from the wheelset, start the second motor to drive the lead screw to rotate, and move the unloading plate along the axial direction of the lead screw, thereby applying a lateral unloading thrust to the wheelset. The lateral unloading thrust is applied in a dynamic loading manner. In the initial stage, the controller dynamically adjusts the speed of the second motor according to the value collected by the thrust sensor, so that the lateral unloading thrust is applied at the first loading slope. When the axial displacement of the wheelset is detected, the current lateral unloading thrust is maintained until the unloading is completed.

2. The method for oiling and unloading train wheelsets according to claim 1, characterized in that, In step S5, the axial displacement of the wheelset is also collected synchronously. When the axial displacement reaches 90% of the total unloading stroke, the loading rate of the lateral unloading thrust is reduced to 20% of the original rate, and the final unloading is completed in constant pressure and speed mode. In constant pressure and speed mode, the controller adjusts the speed of the second motor according to the feedback of the thrust sensor to maintain a constant lateral unloading thrust.

3. The method for oiling and unloading train wheelsets according to claim 1, characterized in that, Before the oil film is initially formed, it is prohibited to apply the lateral unloading thrust to the wheelset, and it is prohibited to drive the wheelset to rotate continuously with a torque exceeding the target rotational torque.

4. The method for oiling and unloading train wheelsets according to claim 1, characterized in that, In S3, the increase in oil injection pressure is a step-by-step increase, with each step increment being 5-15 MPa, and the first preset duration is 1-3 seconds; the threshold for determining the relative rotation trend is: the cumulative angular displacement of the wheelset relative to the axle is greater than 0.3° and the instantaneous angular velocity is greater than 0.01° / s.

5. The method for oiling and unloading train wheelsets according to claim 1, characterized in that, In step S4, the oil injection pressure is controlled to be maintained at the oil injection pressure value when the oil film is initially formed, and this pressure is maintained within a preset pressure holding time. The preset pressure holding time is determined according to the wheelset model and has a value range of 5-30 seconds. If the oil injection pressure drops beyond a preset threshold within the preset pressure holding time, the hydraulic station is activated to replenish the pressure and restore it to the pressure value at which the oil film was initially formed.

6. The method for oiling and unloading train wheelsets according to claim 1, characterized in that, In step S5, during the application of the lateral unloading thrust, when the actual lateral unloading thrust detected by the thrust sensor exceeds a preset safety threshold, and the displacement sensor detects that the axial displacement of the wheelset has not changed, the controller immediately controls the second motor to stop unloading to prevent the axle from being damaged due to overload.

7. A train wheelset oil injection and unloading device, applied to the train wheelset oil injection and unloading method according to any one of claims 1-6, characterized in that, The device includes a base and a gantry frame. The gantry frame is fixedly mounted on the base. The inner wall of the gantry frame has a push rod, which is used to press against the end of the axle during unloading to limit axial movement of the axle. A set of support columns for supporting the wheelset assembly to be unloaded is also fixed on the base. An unloading plate for unloading the wheelset is installed between the two support columns, and the top of the unloading plate is open. A clamping mechanism is slidably mounted below the top of the gantry frame. The clamping mechanism includes an arc-shaped frame, the arc-shaped inner wall of which faces the wheelset to be unloaded. An arc-shaped guide groove is formed on the inner wall of the arc-shaped frame, and transverse guide grooves are formed through the arc-shaped frame on both sides, communicating with the arc-shaped guide grooves. An arc-shaped toothed plate is fixedly installed on one side of the arc-shaped frame. A sliding block is movably fitted in the arc-shaped guide groove. Two clamping arms are slidably installed at the bottom of the sliding block. The two clamping arms are used to clamp the wheelset to be unloaded. A hydraulic station and controller are also provided on one side of the base. The hydraulic station is connected to the oil filling port of the wheelset through an oil pipe. The clamping mechanism also includes a guide shaft. The guide shaft is movably installed in the transverse guide groove and passes through the sliding block. A drive gear is fixedly installed at one end of the guide shaft, and the other end is fixedly connected to the output end of the drive motor. A sliding cavity is also opened at the bottom of the sliding block. A support shaft is transversely arranged in the sliding cavity. Two clamping arms are respectively fitted on the support shaft.

8. The train wheelset oil injection and unloading device according to claim 7, characterized in that, A spring is also provided between the two clamping arms, and the two inner sidewalls of the arc-shaped guide groove are also equipped with expanding plates. When the outer sides of the two clamping arms contact the corresponding expanding plates, the two clamping arms gradually approach each other radially under the guidance of the expanding plates and clamp the wheelset.

9. The train wheelset oil injection and unloading device according to claim 7, characterized in that, The device of this invention also includes an oil injection pressure sensor, which is installed on the oil pipe connecting the hydraulic station and the oil injection port, for real-time acquisition of the oil injection pressure value; a torque sensor, which is installed on the output shaft of the drive motor, for real-time acquisition of the actual rotational torque output by the drive motor; a thrust sensor, which is installed on the unloading plate, for real-time acquisition of the lateral unloading thrust value applied by the unloading plate to the wheelset; and an angle sensor, which is installed on the clamping arm or the output shaft of the drive motor, for real-time acquisition of the angular displacement of the wheelset relative to the axle. A displacement sensor is installed on the unloading plate to collect the axial displacement of the wheelset in real time.

10. A train wheelset oil injection and unloading system, comprising a controller, characterized in that, The controller includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, implements the unloading method described in any one of 1-6 above.

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