极端工况静压支承转速与承载力的耦合与协同

Coupling and collaboration of rotational speed and load capacity of hydrostatic bearing under extreme working conditions

为了解决极端工况下静压支承高精度稳定运行问题,建立静压支承旋转速度和承载能力耦合关系数学模型,研究静压支承微间隙油膜综合润滑性能的载荷特性和速度特性,实现旋转速度和承载能力的合理匹配与协同。本文搭建了静压支承旋转速度与承载能力匹配关系测试平台,验证了理论分析和数值模拟的正确性。研究表明:极端工况时,随旋转速度增加,油膜温升增大和油腔平均压力减小,其承载能力逐渐下降,旋转速度和承载能力呈非线性关系;随承载增加,油膜温升和油腔平均压力增大,其旋转速度相应降低,承载能力与旋转速度仍然保持非线性关系,旋转速度和承载能力具有确定合理匹配值。建议通过减少油腔摩擦面积、采用低粘度润滑油、适当加大油膜厚度等方法,增加高速重载极端工况静压支承的承载能力或提高旋转速度。

To achieve high precision and stable operation of hydrostatic bearings under extreme working conditions, a mathematical model of the coupling relationship between the rotational speed and load capacity of the hydrostatic bearing under extreme working conditions and at high speed and heavy load is established to simulate the load and speed characteristics of the comprehensive lubrication performance of micro clearance oil film in the hydrostatic bearing, and reasonable matching and coordination of rotational speed and load capacity are achieved. A test rig for the matching relationship between hydrostatic bearing rotational speed and load capacity is built to verify the correctness of the theoretical analysis and numerical simulation. Results show that the temperature rise of oil film increases, the average pressure of oil recess decreases, and the load capacity decreases gradually with the increase in the rotational speed. Moreover, the relationship between the rotational speed and the bearing capacity is nonlinear under extreme conditions. With the increase in the load, both the temperature rise of the oil film and the average pressure in the oil recess increase, the rotational speed decreases accordingly, and the load capacity and rotational speed maintain a nonlinear relationship. The rotational speed and the bearing capacity have a reasonable matching value. Findings suggest that the bearing capacity or rotation speed of hydrostatic bearing under high speed and heavy load extreme conditions should be increased by reducing the friction area of the oil cavity, using low-viscosity lubricating oil, and appropriately increasing the thickness of the oil film.