Lubrication characteristics of the worn slipper in the slipper-swashplate pair

Abstract

Purpose This paper proposes the lubrication characteristics of the worn slipper in the slipper–swashplate pair. The mathematical analysis of lubrication characteristics of slipper with the measured surface roughness distribution is introduced. Based on the results from the test rig, it carries out the result compassion in different operating conditions. Design/methodology/approach This paper introduces the measured surface roughness distribution of new and used slippers and generates the oil film thickness distribution with it. An average flow Reynolds equation of the pressure distribution is introduced too. The experimental results are carried out on a novel adjustable oil film thickness test rig. Findings The surface roughness of the worn slipper enlarges the reacting force and torque only if the oil film thickness is small. When the ratio of oil film thickness to the root mean square of surface roughness is much smaller than 3, the influence of it on torque is obvious. Originality/value Different surface roughness of worn slipper proposed in this paper has an influence on the lubrication characteristics. As the slipper is worn after a period of use, the changed lubrication characteristics should be considered in the slipper design.

A new test method for simulating wear failure of hydraulic pump slipper pair under high-speed and high-pressure conditions

“…At present, scholars attach great importance to the fault diagnosis of high-speed, high-pressure hydraulic pumps, which has become an important research direction in the field of fault diagnosis (Tang et al, 2022a;Zhu et al, 2022). As a moving component with the most complex motion mechanism and the most severe working environments (Chao et al, 2018;Wang and Shi, 2021), the slipper pair easily leads to wear failure (Wu and Yu, 2018;Guo et al, 2020). However, due to the closure of the hydraulic pump structure, the fault concealment is extremely strong, and the fault data are difficult to obtain, especially under high-speed and high-pressure conditions (Tang et al, 2021b;Tang et al, 2022b;Tang et al, 2022c).…”

Impact Analysis of Worn Surface Morphology on Adaptive Friction Characteristics of the Slipper Pair in Hydraulic Pump

“…Under the condition of high-speed and heavy-duty operation of the hydraulic pump, it is often faced with severe conditions such as frequent strong load impact, high contact pressure, and fast start, which lead to inevitable wear failure on the surface of the slipper, which decreases the friction performance of the slipper, seriously affects the reliable bearing capacity and working efficiency of the slipper pair, and threatens the stability and service life of the whole pump [ 4 , 5 ]. Different from ordinary sliding friction pairs, the bearing adaptability of slipper pairs in the working process often makes the slipper pairs in the dynamic and static pressure mixed lubrication state, showing complex friction-adaptive characteristics in the early wear stage, which makes the slipper pairs have better anti-wear performance than ordinary sliding friction pairs, and can play a certain role in repairing the early surface wear of slipper pairs [ 6 ]. The establishment of a friction model of the mixed lubrication state of slipper pairs is the basis for revealing the friction adaptive mechanism [ 7 , 8 ].…”

Study on the Lubricating Characteristics of the Oil Film of the Slipper Pair in a Large Displacement Piston Pump

“…When the axial piston pump is working, there is an oil film formed between two sliding surfaces of the slipper pair to support and lubricate them. The oil film cannot be too thin or too thick; too thin will cause excessive wear and slipper burning damage, and too thick will have a small sealing effect, large leakage, and low volume efficiency [6][7][8][9]. The development of this type of pump is limited by the problem of friction film lubrication.…”