摘要：A new hydraulic system of a novel automatic transmission (AT) was designed. The dimension and structure of valves and cylinders were designed by theoretical calculation. The dynamic simulation model of hydraulic system of AT was established by ITI-SimulationX. Simulation results and theoretical design results were compared to confirm the simulation model. Based on the confirmed simulation model, the simulation results of pressure and flow of the hydraulic system were analyzed. The dynamic simulation method is very helpful for designing and analyzing the performance of hydraulic system and further optimization design. The theoretical design method and dynamic simulation model are feasible for the real industrial applications. The research results can be used in hydraulic system design and optimization.

摘要：As the most significant performance, compliance of hydraulic system is defined as the capacity to accommodate the sudden change of the external load. Due to the different requirements of the compliant tasks, the existing method for mechanical systems cannot be used in the analysis and design of the hydraulic system. In this paper, the definition and expression of compliance of hydraulic system are proposed to evaluate the compliance of the hydraulic system operating under sudden change load. Because the unexpected geological conditions during excavation may exert sudden change load to the shield tunneling machine, the compliance theory has found a right application in the thrust hydraulic system. By analyzing the basic operating principle and the commonly used architectures of the thrust hydraulic system, a compliance based thrust hydraulic system design method is presented. Moreover, a tunneling case is investigated in the paper as an example to expound the validation of design procedure. In conclusion, the compliance of the hydraulic system can be served as an evaluation of the capability in conforming to the load impact, giving supports for the design of the thrust hydraulic system of shield tunneling machines.

摘要：hydraulic systems provide a clean and stable supply of hydraulic fluid for subsea valves and actuators installed on the subsea bed in subsea production *** control systems are used for contemporary subsea fields instead of installing the control system on *** all-electric subsea systems are state-of-the-art with benefits such as health,safety,and environment improvement,as well as efficiency and lower cost,hydraulic systems are still used for the development of many subsea *** of the main questions in the selection of a subsea hydraulic field is whether to choose an open or closed loop hydraulic *** main characteristic of an open loop hydraulic system is that the hydraulic fluid is discharged into the marine environment during the actuation of the subsea ***,the hydraulic fluid is returned to the topside facilities through an umbilical system in a closed loop *** that closed loop systems are more eco-friendly,the main question in this research is to examine the effect of the actuator connection of the closed loop system on actuator *** cases of actuated valves connected to a closed loop system are analyzed in this *** first is a 71/*** slab gate valve in the pressure class of 517 bar with a linear spring return fail-safe close(FSC)actuator located on a manifold *** data indicates that the piston rod and cylinder diameter of the FSC linear actuator should be increased by some millimeters due to the accumulation of hydraulic oil at the bottom of the *** hydraulic oil in the closed loop system helps in closing the actuator and spring force,so the spring constant and torque should be reduced as a *** second case involves a *** ball valve in the pressure class of 517 bar with a double-acting fail-as-is rack and pinion *** conclusion in this case is to avoid making any change in the design of double-acting actuator in connection to the closed loop sy

摘要：The weighing system designed for large structure object is mainly composed of three parts. The part of hydraulic system is made up of hydraulic cylinders, high pressure hydraulic hoses and electric pumps; the part of computer controlling system comprises pressure sensors, displacement sensors, data acquisitions, RS 485 network and the computer controlling model; the part of loading system is composed of the fulcrum structure and the concrete girder. The measurement principle and composition of the weighing system are discussed in this paper. Credibility and security of the weighing system are fully considered during the design phase. The hydraulic system is controlled by pilot operated check valves in case of the sudden loss of system pressure. The states of all gauges and RS485 network are monitored by computer controlling system functioning in different modules. When the system is running incorrectly, it will be switched to manual mode and give alarm. The finite element method is employed to analyze fulcrum structure so that the system has enough intensity to be lifted. Hence the reliability of the whole system is enhanced.

摘要：As a core part of subsea production systems,subsea control modules(SCMs)are costly,difficult,and expensive to install and inconvenient to use in underwater ***,performance and function tests must be carried out before launching *** study developed a testing device and an SCM test by investigating SCMs and their *** testing device includes four parts:a hydraulic station,an SCM test stand,a signal generating device,and an electronic test ***,the basic indices of the testing device were determined from the performance and working parameters of the ***,the design scheme of the testing device for the SCM was tentatively proposed,and each testing device was ***,a practical measurement of the SCM,in combination with the hydraulic station,SCM test stand,signal generator,electronic unit,and highpressure water tank,was carried out according to the test *** measurement mainly involved equipment inspection before testing and an experimental test for the *** validity and feasibility of the testing device and method were simultaneously verified through an association test.