To solve the test mass misalignment problem in NIM-2 joule balance, a new suspension system with an overlapped-flexure hinge is proposed. The overlapped structure of this flexure hinge can guarantee the forces to act on the same pivot point, so the first type error torque caused by deviation of the weighing pan can be eliminated without any adjusting process. In addition, to eliminate the transmission of the second type error torque caused by tilt of the weighing pan, a mathematic model is established to analyze the stiffness requirement of the overlapped-flexure hinge. The overlapped-flexure hinge is designed based on the above calculated stiffness, and new suspension system have been assembled. Finite element simulations and experiments are used to prove the effectiveness of this new suspension system. The results show that by meeting the stiffness requirement of the overlapped-flexure hinge, the test mass alignment error can be eliminated effectively.

为了解决NIM-2焦耳平衡中的测试质量偏差问题，提出了一种新的带有重叠挠性铰链的悬架系统。该挠性铰链的重叠结构可确保力作用在同一枢轴点上，因此无需任何调整过程即可消除由秤盘偏移引起的第一类误差扭矩。另外，为消除由秤盘倾斜引起的第二类误差扭矩的传递，建立了数学模型来分析重叠挠曲铰链的刚度要求。重叠挠曲铰链是根据上述计算的刚度设计的，并且已经组装了新的悬架系统。有限元模拟和实验被用来证明这种新型悬挂系统的有效性。