The structural parameters and performance indicators of the imported universal UN seals can meet the design requirements. The UN-type seal has a Y-shaped cross section and belongs to the lip seal. The advantage is that the frictional resistance is small, only 40% of the “0†seal. The frictional resistance of the start is not related to the length of the parking time and the internal pressure. Large, stable operation; good stability, reliable sealing performance; good pressure resistance, long service life, wide application pressure range; simple sealing device structure, sealing can be realized in a single turn, low processing cost; easy installation, no need Special tools.
Safety Precautions Seals and guards are sealed with a built-in “0†seal. Limit piston travel. Since the bolt stretch is much smaller than the piston design stroke, and the structure is limited, it is not suitable to install the limit device. (The limit device functions as a safety protection function, but when the misoperation occurs, the limit device is more destructive. In the Urumqi Locomotive Depot, the dangerous action of the fixed tensioner of the imported tensioner is broken and rushed into the sky due to misoperation. In each stretching operation, only the pull body and the cylinder head and the main bearing The bolt is tightened until the piston is pressed to the bottom dead center position before stretching.
Main measures taken 1 In October 2001, the first prototype was tested at the Hami Railway Locomotive Depot. The high-pressure hose connecting the two hydraulic cylinders is bent forward in close contact with the crankshaft gear adjacent to the ninth main bearing, and there are unsafe factors, such as changing the joint position to make it bend backward, which affects the operation line of sight. The consequence is that the main bearing tensioner is scrapped. After careful research, combined with the opinions of the field operators, the design is modified as follows: increase the height of the lower part of the cylinder, but at the same time reduce the height of the slot on the cylinder; change the high-pressure hose connecting each cylinder to a rigid straight tube, and Install a safety shield.
The four hydraulic cylinders of the cylinder head bolt tensioner prototype are jointed in the hydraulic system design. During the test, the distance of the last cylinder piston in the four hydraulic cylinders is found to be moved downward after the system is unloaded. Less than the other three cylinders, after analysis, it is determined that the cylinder is not well returned.
Therefore, in order to ensure the synchronization of the four cylinders and increase the distance of the downward movement of the piston as much as possible, the workload of the manual compression piston is reduced, the working efficiency is improved, and at the same time, in order to ensure safety, the proper diameter of the oil pipe and the pipe joint is determined. Content of the study. Measures taken: Re-purchase the high-pressure hose with a diameter of 6; under the same test conditions, design and manufacture the diameter-order oil pipes, carry out comparative experiments, observe the effect, and determine the best effect of the rigid oil pipe with a diameter of 5.
In use, it has been found that the lever for dialing the nut in the supplied accessory has a short service life. This is due to oil stains and even sand between the nut and the screw during the disassembly operation. The lever is hard to be used when it is used. The material of the lever is hard and easy to break. The material is soft and easily deformed. Finally, it is scrapped on the diesel engine. The valve stem has improved, but the service life is still not ideal. This problem needs to be solved.
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