Zhang Yanqin

Simulation and experiment of performance characteristics of hydrostatic bearing under different working medium

The hydrostatic bearing has been a mature technical product and gradually applied in a series of light weight and high precision equipment, and the lubrication performance of hydrostatic bearing is particularly important for machines running, it will directly affect the processing efficiency and the processing precision of machine tools. In this paper, we studied the influence of lubrication performance of hydrostatic bearing on velocity field and pressure field by using five kinds of common lubrication medium of lubricating oil HL-15, HL-22, HL-32, HL-46, HL-68 under the hydrostatic bearing running in load 40t, full load 150t and the rotating speed of 0r/min, 10r/min, 20 r/min, 30 r/min, 40 r/min, 50 r/min, 60 r/min. This paper explored the distribution characteristics of velocity field and pressure field, and simulated the state by using FLUENT6.3.26 software. The results show that: The oil cavity pressure increases with the augment of lubricant viscosity, moreover, the lateral flow velocity is greater than the inner velocity, and its speed is directed to the rotating direction and the fluid flow respectively to the outward side, the results accord with the actual operation state of hydrostatic bearing.

Multi-pad hydrostatic bearing oil film temperature characteristics under different working mediums

Multi-pad hydrostatic bearing is widely used in heavy NC equipment, because lubricating oil can reduce friction on the surface of the two movements, so it is very important to choose the correct lubricating oil. The essay records the temperature change statistics of oil slick of HL-15, HL-22, HL-32> HL-46> HL-68 when the external load is 40t and rotation speed is 20r/min, then using GAMBIT2.3.16 meshing and setting boundary conditions. The results of FLUENT6.3.26 simulation are given to explore on the distribution characteristics of temperature field in five kinds of working mediums. It can easily be deduced that using different lubricating oil the temperature rise is different. In other words, the viscosity of the lubricating oil is the decisive factor, the higher viscosity, the higher temperature.

Improvement of hydrostatic bearing workbench structure based on the thermal deformation

The deformation of hydrostatic bearing rotary workbench is the direct factor that affects working accuracy. In this paper, taking the hydrostatic bearing rotary workbench as research object, the improvement model of the hydrostatic bearing workbench structure is established. In different speed conditions, thermal deformation calculation for workbench is conducted by using finite element method and fluid solid coupling technique. By comparison of the results of the model before and after the improvement, it is concluded that the thermal deformation of the workbench can be decreased if we add rib plate appropriately. Conclusion can provide guidance for the production of the hydrostatic bearing workbench, and it also has certain scientific significance to improve the accuracy of CNC machine tools.