English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Based on the model of gas liquid two-phase flow of lubrication oil in bearing chamber, the paper calculates the flow characteristics of the lubricating oil in the simplified model of the high-speed angular contact ball bearing chamber by VOF method and MRF model, obtains the pressure and distribution of lubricant oil. The cause of the influence of the lubricating oil into the chamber and the influence of the rotational speed of the bearing and lubricating oil inlet flow parameters such as the impact on the oil volume fraction are analyzed. The results show that bearing high-speed rotating stage, the two phase flow field in the bearing chamber between the bearing rings has the characteristics of periodic pressure. The volume fraction of the oil in the chamber decreases with the increase of the bearing speed, and is increased with speeding up the lubrication flow rate nonlinearly, which provides a theoretical basis for the design of high DN bearing lubrication. Introduction Angular contact ball bearings can withstand radial and axial load at the same time, and have excellent speed performance, widely used in aviation engine spindle, high-speed spinning spindle, and other mechanical parts. Its stable working condition is very important to the whole system. Due to the structure of oil injection lubrication is easier to achieve, and has good lubrication effect [1]. Therefore, it is widely used in high speed angular contact ball bearings. Because of bearing high speed rotating, lubricating oil into the bearing chamber by the rolling element, cage stirring and centrifugal force, the formation of the flow state of gas-liquid coexistence with the chamber air, namely the gas liquid two phase flow. Gas-liquid two phase flow in the flow and distribution of bearing cavity for bearing lubrication performance and service life has an important influence. In recent years, domestic and foreign scholars in the field of bearing chamber two-phase flow launched a series of research work. Glahn and Wittig[2] were used to study the effects of interfacial shear stress, gravity and heat transfer on the oil film motion in the bearing chamber. Coe, etc.[3] found that the bearing oil chamber volume fraction from 2% to 3%, the bearing temperature rise calculation results are comparatively consistent with the experiment. Hadden[4], such as through a lot of experimental research is recommended to use the oil volume fraction below 5% for the bearing lubrication and cooling effect is better. Chen, etc.[5] studied the aircraft engine bearing chamber gas liquid two phase flow field in the deformation and movement of the droplet. The numerical simulation of gas liquid two phase flow in the oil lubricated rolling bearing was carried out by Hu, et al[6], which provided the basis for optimizing the jet lubrication device and enhancing the cooling effect. These results are of great significance for understanding the gas-liquid two-phase flow in the bearing chamber. However, for high speed rolling bearing ring oil lubrication between 2017 2nd International Conference on Mechatronics and Information Technology (ICMIT 2017) Copyright © (2017) Francis Academic Press , UK 176 research rarely seen reports that the present study focused on the determination of lubrication parameters, the formation and distribution of oil film, production and the movement of the droplet. There is a lack of understanding the gas-liquid two-phase flow in the internal bearings. Based on the angular contact ball bearing 7306 as the research object, the VOF method was used to track gas-liquid interface and description bearing parts movement of MRF multiple coordinate system. Analyze the pressure distribution in the bearing chamber, the oil volume fraction with bearing rotational speed and the inlet flow rate of lubricating oil. To improve rolling bearings under high DN value provides the theory basis for oil lubrication. Mathematical Model and Control Equation VOF Method and MRF Model While the high-speed angular contact ball bearing in the gas-liquid two phase flow state, but the chamber flow approximation think there are two incompatible and incompressible fluid flow system, consisting of each phase is still meet the basic control equation of fluid. This paper uses the VOF method to introduce a variable φ, namely the calculation of the volume fraction of unit (the air for the first phase, the second phase of lubricating oil). If φl=0, the unit all the air; if φl=1, the unit all occupied by oil liquid; if 0<φl<1, the unit is at the gas-liquid interface, unit for gas-liquid two-phase fluid; in each control volume, the volume fraction of two phase and 1. High-speed angular contact ball bearing in high speed, bearing inner ring, cage and rolling element with their respective speed of revolution, the position of the nozzle is fixed, in order to accurately simulate the bearing chamber form of exercise, two sets of coordinate system is adopted to improve the movement description, namely the method of multiple reference frame (MRF)[7]. When the rotation basin is rotated with angular velocity ω, the relationship between the relative velocity vr of the point of the vector at r and the absolute velocity v in the fixed coordinate system can be expressed as: r ω ν ν × + = r (1) Rotating coordinates of fluid mass, momentum and energy conservation equation can be described as[8]: 0 = • ∇ + ∂ ∂ r t ρν ρ (2)

Numerical Investigation of Two-Phase Air/Oil Flow in High-speed Angular-contact Ball Bearing Chamber