Piston Hydraulic Motor Research Articles

Water hydraulic axial piston motor cavitation characteristics based on CFD technology

PurposeThe purpose of this paper is to analyze the cavitation characteristics of a water hydraulic axial piston motor (WHAPM) to improve the water motor performance, to reduce the vibration and noise and to prolong the service life of the motor.Design/methodology/approachThe computational fluid dynamics (CFD) software PumpLinx is chosen to do cavitation analysis of the WHAPM. In this case, first, cavitation mechanism of the water piston motor is analyzed in depth. Then, considering the effects of bubble dynamics, the rate of phase transition, turbulence effects and non-condensable gas, the full cavitation model is selected, the dynamic CFD numerical model of internal flow field on the water hydraulic piston motor is established based on PumpLinx software and the fluid cavitation inside is numerically studied. Finally, the influence of the valve plate and pistons on motor cavitation is analyzed.FindingsResearch results show that there are two serious cavitation regions: one is the pressure transition region of the valve plate that is near the top dead center, and the other is the low-pressure region of the piston that is near the low-pressure transition area. Moreover, the more serious cavitation area is on the valve plate region.Originality/valueThe simulation results show that the proposed algorithm is able to detect the cavitation characteristics of the water piston motor. Besides, it is deduced that valve-plate structure optimization is more important than pistons to reduce cavitation influence.

Speed characteristics analysis and simulation of the water hydraulic axial piston motor

Purpose The purpose of this study is to analyze the speed characteristics of the water hydraulic axial piston motor. The speed performance of water hydraulic piston motor which uses water as medium is different from that mineral oil one. Design/methodology/approach To analyze the speed characteristics of the water hydraulic motor, the speed model of a swash plate water hydraulic piston motor is developed theoretically and a simulation model with AMESim is built. Findings The effects of clearance between friction pairs and input pressure on the speed are analyzed and compared between the theoretical and numerical models. Originality/value The results of the theoretical and simulation models both verify that the clearance of friction pairs is the key factor in the hydraulic piston motor’s speed.

Non-probabilistic wear reliability analysis of swash-plate/slipper of water hydraulic piston motor based on convex model

Water hydraulic piston motor is one of the important transmission components in a water hydraulic system. For lack of enough experimental information to analyze the reliability in water hydraulic motor design, the convex model is chosen as wear reliability model for hydraulic friction pairs, which is more economical and reasonable than the interval model. The non-probabilistic reliability index based on the convex model is established using first-order Taylor series expansion, and the non-probabilistic reliability model of wear reliability analysis for the friction pair of swash-plate/slipper in water hydraulic piston motor is introduced based on the convex model. For the non-probabilistic reliability model, only the bounds on uncertain parameters are needed, instead of probabilistic density distribution or statistical quantities. Numerical examples are used to illustrate the validity and feasibility of the presented method.

Dynamic vibration analysis of a swash-plate type water hydraulic motor

This paper presents the study of the dynamic analysis of a swash-plate water hydraulic motor in a modern water hydraulic system. A swash-plate mechanism is modeled as a system with three masses and 14 degrees of freedom (DOF). In order to evaluate the applicability of the dynamic model, the numerical simulation analysis of the dynamic response of the model due to pressure pulsation is presented and compared with experimental results. A series of the dynamic vibration characteristics of the water hydraulic piston motor are studied by the numerical simulation. It is effective for the model to simulate the vibration signal of the casing in the hydraulic motor. The waveform and frequency of the simulated signal is similar to the experimental signal. The simulated signals in other directions show that the vibration signals in all the directions mainly consist of the hydraulic pump and hydraulic motor rotational frequencies.

EXPERI_VIENTAL STUDY OIL THE PERFORMANCE ESTIVIATION EFFICIENCY MODEL OF A HYDRAULIC AXIAL PISTON MOTORS

Performance of a hydraulic piston motor is very difficult to estimate in advance before experiment. But it is highly required because, if an efficiency model for performance estimation is already in hands, the model enables one to design a hydraulic motor with good efficiency at a designated operating point. Recently such a performance estimation model is developed by H.S. Jeong. In this paper, validity and accuracy of the performance model is studied by comparison with experimental efficiency test data.