Abstract: This article focuses on the wear problem of the clutch detachment slider of the DC-32 tamping truck's triple hydraulic pump. By installing an adjustable limit device, Z finally solved this problem, extended the service life of the triple hydraulic pump clutch, and ensured that the equipment is in good working condition.
Keywords: DC-32 tamping truck; Hydraulic system; Triple pump; Detaching device; Clutch; Wear and tear; Adjustable limit
1. Preface
The DC-32 tamping truck (as shown in Figure 1) has been widely used in railway line repair, speed increase line renovation, and new line construction nationwide, and is the main model for railway line maintenance in China. The DC-32 tamping truck is a double sleeper tamping truck, with a step-by-step operation mode. It can perform track lifting, track shifting, leveling, ballast tamping under the sleeper on both sides of the steel rail, and ballast tamping at the sleeper end. The operating system of the vehicle adopts open hydraulic transmission. Hydraulic transmission has the advantages of simple structure, compact layout, large output energy, small size, sensitive response, stepless speed regulation, easy automatic control and overload protection, stable transmission, safety and reliability, light weight, long service life, and easy replacement.
The hydraulic system of the DC-32 tamping truck consists of three hydraulic pumps, including one T2SDCB triple vane pump and two T6D double vane pumps. These three hydraulic pumps are installed on the power take-off of the power shift gearbox and are driven by a diesel engine to provide pressure oil to each hydraulic circuit. The three hydraulic pumps provide power for the oil pump and vibrating oil motor, the lifting and clamping of the tamping device, the lateral movement of the tamping device and the lifting of the tamping device, the lifting and shifting device, and the operating oil motor, as well as the brake and support oil cylinder.
Fig.1 DC-32 tamping truck
The DC-32 tamping truck triple pump needs to be manually disengaged during the operation and operation transition process. If operated for a long time, the position of the detachment lever handle will slowly move outward, causing wear on the detachment slider, and ultimately causing difficulty in the detachment of the triple pump, affecting the operation. The good functioning of the decoupling device of the triple hydraulic pump is a determining factor for the normal operation of the DC-32 tamping truck. At present, there are several DC-32 tamping trucks in our section that were manufactured in 2006. After investigation, DC-32 tamping trucks were only equipped with detachment limits for two dual pumps at the factory. Therefore, in recent years of use, the triple hydraulic pump clutch assembly needs to be replaced every year; Otherwise, the clutch disengagement slider of the DC-32 tamping truck's triple hydraulic pump is worn, seriously affecting the normal operation of the equipment and the construction of tamping, lifting and shifting operations. This article extends the service life of the clutch and ensures the good condition of the equipment by installing an adjustable limit device.
2. Analysis and Solutions of Wear in the Application of Triple Hydraulic Pump Clutch
During the operation and operation transition process of the DC-32 tamping truck triple hydraulic pump, manual detachment is required. After prolonged operation, the position of the detachment pull rod handle will slowly move outward, causing wear and tear on the detachment slider. This ultimately leads to difficulty in detachment of the triple hydraulic pump, affecting normal operation and construction. Our unit needs to replace this clutch every year because the value of the triple hydraulic pump is over 300000 RMB. Solving this problem is time-consuming, labor-intensive, and the cost of vehicle maintenance has increased. Additionally, there are significant safety hazards during the operation conversion process.
The actual condition of the triple hydraulic pump decoupling device and the wear of the clutch decoupling slider of the DC-32 tamping truck when it leaves the factory are shown in Figures 2 and 3.
Figure 2 External Detachment Machine
Figure 3 Internal detachment slider
The hydraulic pump is the power source for the hydraulic system of the DC-32 tamping truck. The detachment slider of DC-32 tamping truck is an important component of the hydraulic pump clutch, and the wear of the slider directly determines whether the power of the hydraulic pump can be transmitted to the operating hydraulic system; So reducing the wear of the slider and extending the service life of the clutch is the top priority of equipment maintenance work. After careful analysis and on-site repeated testing, we have made the following improvements to the slider of the pressure pump clutch based on usage.
2.1 Improvement Plan 1
According to the principles of "simple and convenient transformation" and "visual control", before on-site operation of the DC-32 tamping truck, spray "detachment" and "hanging" marks on the detachment handle; And mark the corresponding detachment positions with different colored paint pens on the detachment pull rods of the triple hydraulic pump.
The red mark represents the pump disconnection position, while the yellow mark represents the pump hanging position, making it easier to observe during the detachment process. It is easier to grasp the manual operation force by monitoring whether the triple hydraulic pump is detached and hung in place through markings. The spraying position is shown in Figure 4.
Figure 4 Marking effect at the detachment handle
After one year of improved use of the decoupling rod of the DC-32 tamping truck's triple hydraulic pump, it was found through inspection that for vehicles with newly replaced clutch assemblies, this measure effectively solved the wear of the slider; However, due to different operators, it is necessary to constantly observe whether the detachment has reached the corresponding mark, which has a certain impact on the equipment operation conversion and shortens the pure operation time. This improvement plan requires high personnel requirements, affects the pure operation time, and cannot adapt to the actual application on site.
2.2 Improvement Plan 2
Install an adjustable limit device on the decoupling mechanism of the DC-32 tamping truck.
In order to increase the on-site operation time of the tamping truck, reduce the duration of the detachment process, reduce human factors, expand the adaptability of the adjustable limit device, and ensure the transformation effect, two DC-32 tamping trucks are selected to install the adjustable limit device.
The above two DC-32 tampering vehicles are vehicles that have been in use for 6 months with the disengaged clutch and those that have been newly replaced with the disengaged clutch.
Joint bearing at the end of the uncoupling rod of the triple hydraulic pump? Install an adjustable limit device, use mechanical positioning, and secure with self-locking nuts. The limit device of the triple pump plays a fixed role in position after being detached and hung in place, and the installation plan is shown in Figure 5.
Figure 5: Installing an adjustable limit device on the decoupling mechanism of DC-32 tamping truck
After installing an adjustable limit device on the decoupling mechanism of the DC-32 tamping truck's triple hydraulic pump for one year, it was found through inspection that this measure effectively solved the wear of the sliding block for vehicles with newly replaced clutch assemblies. By mechanical positioning, the requirements for operators in the detachment process have been reduced. Adopting an adjustable limit device to adapt to the current situation of vehicles at different times on site, extending the service life of the clutch assembly, reducing work power, eliminating hidden dangers, and ensuring on-site flow operation.
2.3 Analysis and Summary of the Wear Problem of the Clutch Detaching and Sliding Block of the Triple Hydraulic Pump on the DC-32 Tamping Truck
(1) Equipment design defects. The DC-32 tamping truck (D08-32 automatic leveling tamping truck) is a large-scale road maintenance machinery that has been domestically produced using the technology of Palsser&Theurer Company in Austria. This machine is a double pillow tamping truck, with a step-by-step operation. Capable of carrying out track lifting, track shifting, leveling, tamping of ballast under the sleeper on both sides of the steel rail, and tamping of ballast at the sleeper end. The power of the above operation performance is the hydraulic system, and the detachment pump process is an important link in the process of operation and operation conversion. When the equipment leaves the factory, only limit devices are installed on the two double pump decoupling devices. There is no status monitoring and limit device for the detachment of the triple pump, which can easily cause wear on the detachment paddles of the triple pump and cause abnormalities in the hydraulic system, which cannot meet the operational requirements.
(2) Differences in the quality of operators. The personnel of the operation team update frequently and have insufficient understanding of the importance of the DC-32 tamping truck detachment pump process. The newly hired personnel simply believe that the detachment pump is only a mechanical action without any precautions. Actually, the wear and tear of mechanical components is a major factor in the failure of large-scale road maintenance machinery. Improving the quality and awareness of operators is urgent.
(3) The hydraulic system repair items in daily inspection and maintenance, regular inspection and maintenance, annual maintenance, and comprehensive maintenance in the "Maintenance Rules for DC-32k Tamping Cars" (TZY [2014] No. 167) do not specify the inspection items and standards for the decoupling clutch of the DC-32 Tamping Car triple pump.
Therefore, the fundamental reason for the wear of the clutch disengagement slider of the DC-32 tamping truck's triple hydraulic pump is that the disengagement device of the triple pump is not equipped with a limiter.
3. Solutions
(1) Add regular inspection and maintenance items: Check the wear of the clutch disengagement slider of the DC-32 tamping truck triple hydraulic pump every 2 years.
(2) Install an adjustable limit device at the end joint bearing of the decoupling pull rod of the DC-32 tamping truck triple pump, and use mechanical positioning to limit the decoupling device.
4 Conclusion
Through the analysis of the wear and solution of the DC-32 tamping vehicle's triple hydraulic pump clutch during use, it can be seen that the wear reason of the DC-32 tamping vehicle's triple hydraulic pump clutch during use is a design defect. Now, adjustable limit devices have been installed on the decoupling devices of four DC-32 tamping trucks' triple pump in our section. After a period of on-site operation verification, this improvement plan effectively solves the wear of the decoupling slider of the DC-32 tamping truck's triple hydraulic pump clutch, ensuring normal operation and construction on site.
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2023-08-28