Static characteristics of active hydrostatic two-row radial bearing with restriction of output lubricant flow

The design of active hydrostatic radial bearing with smooth cylindrical surfaces and lubricant output flow restrictors in the form of movable rings on membrane suspension is presented. The device is several times less power-consuming compared with known devices of flow control. The bearing has a negative and zero compliance (infinite stiffness), and therefore can be used in machine tools to suppress the negative influence of elastic system deformation on the accuracy of processing. On the basis of two-dimensional model of lubricant flow developed a mathematical model, method and procedure for calculating the bearing load capacity and flow rate. It is established, that the calculation of static characteristics of bearing in the entire range of operating loads can be correctly performed only on the base of two-dimensional model. For small eccentricities the characteristic of zero and negative compliance can be calculated with sufficient accuracy by the simplified method, based on one-dimensional motion of lubricant flow. Bearing of zero or negative compliance have load capacity range, which is 20 - 50% more than conventional bearings of the same overall dimensions. The setting of input throttling slits resistance decisive influence on the optimal static characteristics of the bearing. The optimal values of its resistance for conventional and active bearing are practically identical.