Research On Camshaft Connecting- Rod Type Low Speed High Torque Hydraulic Motors With High- Pressure Rank

Camshaft connecting- rod type low speed high torque hydraulic motor is an important hydraulic actuator that is widely used in many industry fields. At present, making rated pressure rank of hydraulic motors higher has been becoming a stringent problem to be solved, due to the need of vast engineering applications. Because slipper pairs based on traditional design theory could not bear high pressure, all the hydraulic motors whose rated pressure is 25MPa do not adopt hydrostatic bearing structure but rolling bearing structure. There are many kinds of camshaft connecting- rod type low speed high torque hydraulic motors whose pressure rank is 20MPa or below produced by domestic corporations, and they use the hydrostatic bearing slipper pairs. So making pressure rank improved to 25MPa or more based on primary products considering low price and simple technology is of great help to civil corporations.Through experiment and study on CLJM-E3.15 type hydraulic motor, this paper studies on novel camshaft connecting- rod type LSHT hydraulic motors with high- pressure rank: quantificational study the influence of squeezing effect on the formation of hydrostatic bearing slipper pair lubrication films; discuss 3- D dynamic simulating method of virtual prototyping based on multi- software platform making full use of engineering software; bring forward every frictional pairs' countermeasures of novel camshaft connecting- rod type LSHT hydraulic motor with high- pressure rank and hydrostatic bearing slipper pair structure; presenting experiment result to show that expectation of high- pressure rank is realized successfully. The main work is as follows:1. Setting up mathematic model of slipper pair lubrication film formation through squeezing and making quantificational studyPressure-flow analytical formulas of lubrication film of slipper pairs on LSHT hydraulic motors are put forward on the basis of numerical calculation of Reynolds equation of steady state by finite differential method. The bottom surface of slipper pairs is rectangle, and the effect of squeeze flow and pressure differential flow is considered. The dynamic process of lubrication film formation through squeezing is numerical studied by computer simulation. It proves that hydrostatic bearing slipper pairs with large oil cavity is reasonable and effective, and sets up theoretical foundation for the use of slipper pairs structure with large oil cavity. Effects of physical and structural parameters are quantificational studied.2. Carrying out 3- D dynamic simulation on camshaft connecting- rod type low speed high torque hydraulic motor based on multi- software platform3-D modeling, kinematics and dynamitic simulation are carried out on camshaft connecting- rod type low speed high torque hydraulic motor with the help of a virtual simulation method based on multi-software platform. Velocity, displacement etc macroscopic movement characteristics of key components are observed. Influence of working conditions changing and some physical parameters to the performance of hydraulic motors is discussed. FEM study is carried out on connecting- rod working in nearly real conditions. Real working status inside hydraulic motors could be observed through computer simulation of virtual prototyping, and various working process under real conditions could be directly studied. It is provided a new way for optimization or innovation of hydraulic motor design.3. Putting forward a novel camshaft connecting- rod type low speed high torque hydraulic motor with high- pressure rankThe whole strategy and every frictional pairs' countermeasures of novel camshaft connecting- rod type LSHT hydraulic motor with high- pressure rank are put forward: analyzing the holistic study process; formulas should be well chose and temperature compensation of damper should be noticed while designing slipper pairs; working performance of sealing rings should be guaranteed while designing distribution axle. Experiment result validates the whole performance of novel camshaft connecting- rod type LSHT hydraulic motor with high- pressure rank.According to the research on the mentioned problems above, this dissertation expends the high- pressurized problem of camshaft connecting- rod LSHT hydraulic motors. Conclusions summarized here are also helpful to the deep study of other hydraulic motors or pumps with similar structural features.