Yanqin Zhang, Pengrui Kong, Yanan Feng and Lili Guo
To investigate the effects of hot oil carrying (HOC), the purpose of this paper is to present a new calculation method of oil film temperature which takes the effects into account…
Abstract
Purpose
To investigate the effects of hot oil carrying (HOC), the purpose of this paper is to present a new calculation method of oil film temperature which takes the effects into account and defines the factor of HOC.
Design/methodology/approach
Based on finite volume method, the paper studied the temperature characteristics in high speed and the condition of variable viscosity from the temperature field and flow field of the film, and the thermal rule of HOC is revealed. The theoretical values are in good agreement with the experimental results.
Findings
The results show that, for this structure of hydrostatic bearing, the phenomenon of HOC does not occur until the work speed is more than 10 r/min under any load condition. And it always happens in the total range of load, from 0 to 320 kN, when the speed is over 60 r/min. Moreover, the film temperature increases sharply, when the phenomenon happens in high speed, and the influence of the speed is greater than the effect of load on the temperature rise.
Originality/value
The results would help to increase the speed of CNC machine tools and the design on structure of the bearing in engineering practice.
Details
Keywords
Yanqin Zhang, Jichang Sun, Pengrui Kong, Xiangbin Kong and Xiaodong Yu
The purpose of the paper is to analyze the bearing capacity of hydrostatic bearing during the change of film thickness under different working conditions and to improve the…
Abstract
Purpose
The purpose of the paper is to analyze the bearing capacity of hydrostatic bearing during the change of film thickness under different working conditions and to improve the processing efficiency and precision of equipment.
Design/methodology/approach
In this study, Q1-205 double rectangular cavity hydrostatic thrust bearing is selected as the research object. The dynamic mesh method and ANSYS/FLUENT software are used to simulate the curves of oil film thickness and oil pressure under different operating conditions. Finally, the change of pressure in the oil cavity at different operating speeds under a certain inlet flow rate was tested through design experiments.
Findings
When the film thickness was thick, the maximum pressure in the oil cavity at different inlet velocities showed little difference. With a larger inlet flow, the maximum pressure in the oil cavity was higher. The pressure at the edge of the oil seal was linearly distributed. The oil pressure in the downstream side was greater than that in the counter flow side. When the working pressure was low, the pressure in the oil cavity slightly decreased with the increase of working speed. Moreover, the pressure loss at high speed was considerable.
Originality/value
Based on the lubrication theory, the mathematical model of the bearing oil film was set up. The bearing capacity equation of the hydrostatic cavity was derived. The double-rectangular-annular hydrostatic guides studied in this paper have not been reported in previous research literature and the method of dynamic mesh dynamic simulation of variable viscosity is seldom studied before. The bearing characteristics and the change of oil film thickness under different working conditions have been studied systematically and comprehensively. The theoretical analysis results are basically consistent with the experimental results.