Research On Sliding Shoes Hydrostatic Bearing Of Water Hydraulic Axial Piston Pump

Water hydraulics, as a kind of new technology, is widely cared because of its environment-protections and energy-savings. Solving the difficulties in water hydraulics, such as poor lubrication, serious erosion for common metals, and large leakage, are the requirement to redevelop it, which can also promote hydraulics to a new step. On research of water hydraulics, the development of water hydraulic axial piston pump is extremely vital and is much difficult.As one of the four important parts of water hydraulic axial piston pump, the design of sliding shoes friction matching mainly takes hydrostatic bearing. The principle, the characteristics, the structure design and the supporting performance of sliding shoes hydrostatic bearing of water hydraulic pump are analyzed and investigated in this thesis. After deducing simplified general formula, a method for calculating structure and performance parameter of water hydrostatic bearing is presented, in which the throttle function of short damping hole is employed to decrease water film thickness and to improve the bearing performance. In addition, a kind of sliding shoes structure named step-shallow cavity type is presented and compared with the common one, which give more satisfactory results.In oil lubrication theory, the effect of inertia on flow state of lubrication film is generally ignored because the inertia item is far smaller than the viscous one. In water hydrostatic bearing lubrication, however, more accurate research results can be obtained as long as inertia of water flow is considered, because inertia item almost has the same quantitative level as the viscous one. In this thesis, pressure distribution model of water film in sliding shoes supporting clearance with considering inertia is deduced and according curve is drawn to vividly illustrate the effect of inertia on water film.High water saturated vapour pressure leads to the more possible occurrence of cavitation phenomena in water hydraulic pump, and so as in sliding shoes hydraulic supporting without exception. The concept and the producing mechanism of cavitation are introduced and the cavitation analyzing model is deduced, which makes it easy to explain theapproximate region and .the extent of cavitation occurrence in theory. And the wider and deeper research combining with experimental analysis can present a further perfect and feasible reference for sliding shoes design.Experiment is the powerful measure for developing water hydraulics. Therefore, a water hydraulic experiment platform which is being trial-produced at the New Driving Technology Center in Southwest Jiaotong university is introduced in order to lay the base and present an ensure for forth successive research.