Lubricant oil is crucial to the rolling bearings as the main medium of lubricating, cooling, cleaning, and so on. The oil starvation in and around the contacts is harmful to the performance and fatigue life of rolling...Lubricant oil is crucial to the rolling bearings as the main medium of lubricating, cooling, cleaning, and so on. The oil starvation in and around the contacts is harmful to the performance and fatigue life of rolling bearings. Therefore, it is of necessity to understand the behaviors of oil transfer and the patterns of air-oil two-phase flow in bearings, especially with the influence of different capillary properties. This work established a transient air-oil two-phase flow model in a ball bearing based on computational fluid dynamics (CFD). Groups of cases are implemented to investigate the behaviors of oil transfer and air-oil flow under different capillary conditions with speed, surface tension, and viscosity. Flow patterns are classified by the morphological features of the air-oil flow. Staged phenomena are analyzed with flow patterns and reach good agreements with the observations from experiments. It is found that the oil distribution and air-oil flow behaviors in a ball bearing are strongly related to the speed and the ratio of oil viscosity and air-oil surface tension (μ_(oil/σ)). The flow maps imply that the levels of capillary number (Ca) may be the boundaries and the critical points of flow pattern transition between the different flow patterns in bearing.展开更多
Oil transfer pump is the key dynamic equipment in the process of oil and gas gathering and transportation,and its working reliability directly affects the safety of oil and gas storage and transportation.Intelligent d...Oil transfer pump is the key dynamic equipment in the process of oil and gas gathering and transportation,and its working reliability directly affects the safety of oil and gas storage and transportation.Intelligent diagnosis is a key technical method to reduce failure rate of oil transfer pump,ensure the safety of gathering and transportation process,and avoid major safety accidents caused by oil transfer pump failure.Various oil transfer pumps have been emerged in recent decades,and the common fault types and characteristics of oil transfer pump have been brought out in the review.This article highlights on the research of the fault signal and processing methods of oil transfer pump.Firstly,the fault signal of the oil transfer pump is discussed and the advantages and disadvantages of different signal extraction are analyzed.Secondly,the intelligent diagnosis method of oil transfer pump and the shortcomings of the existing methods are pointed out.Finally,the conclusions are given and the future development perspectives of oil transfer pumps are suggested.The main contribution of this review is to give a syn-thetic understanding on oil transfer pumps.展开更多
基金National Key R&D Program of China(2018YFB2000604)the National Natural Science Foundation of China(51805031)and(JSZL2019213B001).
文摘Lubricant oil is crucial to the rolling bearings as the main medium of lubricating, cooling, cleaning, and so on. The oil starvation in and around the contacts is harmful to the performance and fatigue life of rolling bearings. Therefore, it is of necessity to understand the behaviors of oil transfer and the patterns of air-oil two-phase flow in bearings, especially with the influence of different capillary properties. This work established a transient air-oil two-phase flow model in a ball bearing based on computational fluid dynamics (CFD). Groups of cases are implemented to investigate the behaviors of oil transfer and air-oil flow under different capillary conditions with speed, surface tension, and viscosity. Flow patterns are classified by the morphological features of the air-oil flow. Staged phenomena are analyzed with flow patterns and reach good agreements with the observations from experiments. It is found that the oil distribution and air-oil flow behaviors in a ball bearing are strongly related to the speed and the ratio of oil viscosity and air-oil surface tension (μ_(oil/σ)). The flow maps imply that the levels of capillary number (Ca) may be the boundaries and the critical points of flow pattern transition between the different flow patterns in bearing.
基金This study is supported by Sichuan science and technology program(2021ZHCG0013,22ZDYF3009)China National Petroleum Corporation science and technology planning project(2020B-4121)Such supports are greatly appreciated by the authors.
文摘Oil transfer pump is the key dynamic equipment in the process of oil and gas gathering and transportation,and its working reliability directly affects the safety of oil and gas storage and transportation.Intelligent diagnosis is a key technical method to reduce failure rate of oil transfer pump,ensure the safety of gathering and transportation process,and avoid major safety accidents caused by oil transfer pump failure.Various oil transfer pumps have been emerged in recent decades,and the common fault types and characteristics of oil transfer pump have been brought out in the review.This article highlights on the research of the fault signal and processing methods of oil transfer pump.Firstly,the fault signal of the oil transfer pump is discussed and the advantages and disadvantages of different signal extraction are analyzed.Secondly,the intelligent diagnosis method of oil transfer pump and the shortcomings of the existing methods are pointed out.Finally,the conclusions are given and the future development perspectives of oil transfer pumps are suggested.The main contribution of this review is to give a syn-thetic understanding on oil transfer pumps.
