基于空气轴承支撑技术的高准确度大扭矩标准装置研究

介绍了新研制的基于空气轴承支撑技术的20kN·m高准确度扭矩标准装置的工作原理、机械结构、性能试验,评定了该装置的不确定度。该标准装置采用静压空气轴承作为力臂杠杆的支撑部件,力臂系统采用了多部件框架结构,力臂材料采用了低热膨胀系数的因瓦合金材料,砝码加载系统采用了多个砝码组、旋转托盘和升降机构结合的方式,实现了不同量程范围扭矩值测量时加卸荷中不出现逆程。理论分析和性能试验表明:20kN·m扭矩标准装置在100N·m～24kN·m范围内的重复性优于2×10^-5,不确定度优于2×10^-5(k=2)。

Research on High Accuracy Large Torque Standard Machine Based on Air Bearing Technology

A set of high accuracy 20 kN·m torque standard machine based on air bearing technology was newly developed at National Institute of Metrology( NIM). The static air bearing is adopted to support the arm lever at the fulcrum,a multi-part frame structure is used in the arm system,the arm is made of Invar alloy material with a low thermal expansion coefficient. A combination of multiple weight groups,rotating platform and lifting mechanisms is adopted in the weight loading system which can realize the measurement of torque values in different ranges without reverse loading. The working principle and mechanical structure of the machine are introduced,the results of performance test and uncertainty assessment are described. The theoretical analysis and performance tests show that the repeatability is smaller than 2 ×10^-5,the uncertainty is less than 2 × 10^-5( k = 2) in the range from 100 N·m to 24 kN·m.