Study On Engineering Machinery Rotary Joint Durability Test System

The engineering machinery rotary joint is a critical component in the mechanical, mainlyused for engineering machinery hydraulic crane and excavator. The installation location of rotaryjoint is very special which between rotating platform of main engine and driving cab. Therefore,overall of main engine need to be disassembled when maintaining and replacing the rotary joint,and plenty of human and material resources will be cost in these processes.Series tests ofperformance assessment need to be conducted for guarantying the quality as well as avoidingfrequently maintenance and replacement of engineering machinery rotary joint.Engineeringmachinery rotary joint detection requires specialized test equipment, but the test methods anddetection equipment is not perfect in current domestic.Lathe spindle is commonly used to driverotary joint by most enterprises. The test system uses hydraulic system loaded rotary joint anddisplay data based on meter reading of pressure gauge and tachymeter. However, this test methodcannot get the real-time performance parameters like oil pressure, driving torque, revolving speedand so on. Therefore, the error of these tests results is larger by artificial meter reading andmanual fill in test results.Engineering machinery rotary joint durability test system is aschool-enterprise cooperation projects for rotary joint factory durability performancerequirements, test system design and performance analysis of research and testing, testedproducts to meet the requirements.Based on the related literature at home and abroad, combined with domestic andinternational engineering machinery rotary joint durability test system research, proposed thestructural scheme of the experimental system, the test system of the research content isdetermined.Consist primarily of hydraulic control part of the design and research, data collectionas well as the test system PC software development.The test system uses hydraulic system loaded rotary joint, which can guarantee the highpressure reached42MPa by using two-way pressure cylinder. In order to observe the connectionof oil block directly and prevent channel interference, this test system adopt two-dimensionaldesign of hydraulic manifold block by CAD and3D modeling by PRO/E software. In additional,ANSYS software is used to check the strength of the high-pressure manifold block. The resultsindicate that the design of channel wall thickness by using the design formula of hydraulicpipeline can fully meet the strength requirements.Meanwhile, the changing temperature ofhydraulic pressure system is checked and it is guaranteed less than allowable temperaturerise.The simulation model is established by AMESim simulation software. Through performanceanalysis of the hydraulic system, the curve of pressure variation inside rotary joint is generatedby using this simulation model.The S7-200PLC from Siemens Company is used as the core of this testing system, whichrealizes the signal collection and process of temperature, pressure, rotational speed and torquethrough16channel analog input module. It also realizes the control of the electromagnetic valve and electric, revolving speed, revolving steer as well as revolving corner of servo motor.The design of PC interface is based on virtual instrument software LabWindows/CVI, bywhich PLC can communicate with the upper machine through the RS485with turningRS232.The whole test system can collect data from the computer display in real-time, andautomatically generate pressure curve, speed curve, temperature curve and torque curve alongwith time variation.The design and research of this testing system has improved the accuracy of the rotary jointdurability testing, and realized automatic control of testing system and collection of test data aswell as provided a reference for the research and development of rotary joint test equipment indomestic.