Research On Measurement Test Of The Pressure Distribution Of Water Lubricated Bearing

Water film pressure distribution which determines properties and carries capacity of water lubricated bearing is one of the important contents must be considered when designing bearing. In order to verify the accuracy and reliability of the theoretical calculation, the direct and effective method is to establish relative test rig in the research of water film pressure. At present, amount of scholars have carried out relative experiment, but most of experiment tested water film pressure by fixing diaphragm or pressure sensor on the outside of bearing. Obviously, it is convenient, but it has its own shortcomings. That’s because the space for installation is finite and the number of testing point is small. Consequently, the points which can be measured are very limited, so it cannot measure continuous contribution of greasiness pressure along circle, which Affect the accuracy of measurement. In order to solve this problem, dynamically and continuously measuring instant pressure distribution in several circles is particularly developed, which has a certain value of reference and basis for the theoretical study and provide experimental support to perfect theory of water lubricated bearings.The main research work and conclusions of paper are as follows:(1) This essay is based on Hydrodynamic lubrication theory, and focuses on water lubricated bearing. This essay also learn from previous research on greasiness and water film measurement referring to the previous research, to come up with a new approach to measure water film pressure under current condition. Namely, connecting axial and radial diversion hole thrilled on shaft and shaft shoulder. In this way, stressed water can move to sensor through diversion hole to measure the pressure. And on this basis, the mechanical structure, the loading system, the lubrication system, the control system are accordingly reformed. In addition, this essay will also improve and design the test experiment system according to pressure test measurement scheme, including:choice of form of pressure sensor and fixing scheme of it, and signal output method, and data processing analysis software.(2) Based on finite-difference method, this essay generates water film pressure distribution of water lubricated bearing curve by making use of two-dimensional Reynold lubrication equation with Matlab. With initial condition of eccentricity ratio and minimum thickness of water film calculated from Matlab, Fluent can emulate water film pressure distribution curve. Comparing the two results earned above, the relative error is within10%, which shows that the two kinds of theoretical calculation model are feasible and have some practical value.(3) After fixing and debugging the whole experiment devises, the bearing water film pressure will be measured under different rotation speed and loading. By this way, the change law of water film pressure will be gained. The experimental results fit the theoretical calculation results well (the average error is in the range from7%to18%), which is very important to improve theory calculation accuracy of the water film pressure.