基于壁面沟槽气流诱导的高速滚动轴承环间喷油润滑穿透机理研究

The speed of airflow between rings is closed to sonic velocity due to the speed of rolling bearings improving constantly. And so it is difficult to control that lubricating oil penetrates the airflow into the bearing chamber by oil jet lubrication. The mathematical model of three-dimensional airflow around rotating components between the rings of bearings is established to analyze several factors including groove in wall, structure size and speed of bearings. And so the flow characteristic and the formation mechanism of induced airflow based on the groove is investigated. According to characteristic parameters of airflow distribution and jetting oil, the simulation method of gas-liquid two-phase flow in the penetration process of liquid flow is developed to study the movement variation of the atomized droplets and the induced airflow. The penetration mechanism of oil jet lubrication in the induced airflow is obtained finally, which can establish the foundation of oil sufficient supply and ensure high-speed equipment operating safely and reliably. The result of this study is significant for oil jet lubrication system design of higher speed rolling bearings, and it can provide the theoretical basis for the intelligent control of oil jet lubrication and efficient use of lubrication.

随着现代工业对高速滚动轴承转速要求的提高，轴承环间气流接近音速，喷油润滑方法难以控制润滑油穿透环间高速气流进入轴承腔内。本项目通过建立轴承环间高速气体三维绕流数学模型，计算分析壁面沟槽、轴承结构尺寸和轴承转速等因素对环间转动元件绕流流动特性的影响规律，探讨有利于润滑油入射的壁面沟槽诱导气流形成机理，从而获得喷射润滑油的最佳入射位置和入射方向。根据诱导气流和润滑油入射的特征参数，建立诱导气流中润滑油穿透过程的液气两相流数值模拟方法，研究分析环间诱导气流对液相射流受力和雾化的影响，以及液流与诱导气流之间运动物理规律的相互影响机制，获得基于环间壁面沟槽气流诱导的高速滚动轴承环间喷油润滑穿透机理，从而为高速轴承润滑油的充分供油奠定基础，保证高速装备安全可靠的运行。项目成果对滚动轴承突破更高转速的环间喷油润滑设计有重要意义，并为环间喷油润滑的智能控制和润滑油的高效利用提供理论基础。

本课题通过建立高速滚动轴承环间高速气体三维绕流数学模型和润滑油穿透过程的液气两相流数值模拟方法，研究了基于壁面沟槽气流诱导的高速滚动轴承环间喷油润滑穿透机理。本研究以高速角接触球轴承为研究对象，首先计算分析了轴承DN值在1×10e6至6×10e6范围内，壁面多种沟槽形式对环间转动元件绕流流动特性的影响规律。通过研究环间诱导气流对液相射流受力和雾化的影响规律，以及液流与诱导气流之间运动物理规律的相互影响机制，根据有利于润滑油入射的壁面沟槽诱导气流形成机理，获得了诱导沟槽开设的最佳方法，以及喷射润滑油的最佳入射位置和入射方向：诱导沟槽开设方向和尺寸与轴承转动的DN值密切相关；喷嘴径向位置在无量纲径向距离诱导沟槽0.2至0.3处，喷射角度与诱导沟槽间夹角约为15°-30°时进入轴承沟道的油液体积分数最佳。本研究结果为高速轴承润滑油的充分供油奠定了基础，保证高速装备安全可靠的运行。同时对于认识高速滚动轴承环间高速气流和喷射润滑油之间的相互影响规律提供了一定的启示性线索。项目成果对滚动轴承突破更高转速的环间喷油润滑设计有重要意义。