A dynamic loading system for high-speed motorized spindle with magnetorheological fluid

A high-speed dynamic loading test is a key step when testing the dynamic performance and running quality of a high-speed motorized spindle. A loading test is very difficult to perform at high speeds. Based on the rheological behavior of the magnetorheological fluid, a novel high-speed dynamic loading system for a high-speed motorized spindle was designed, fabricated, and tested. The working principles and structure of this loading system are described. The torque model of the loader was derived based on the Herschel–Bulkley model and electromagnetic simulation using the finite element method. In addition, the torque–current relationship under different speeds was analyzed by experiments, and we found non-linear relationships between the viscosity and shear stress of the magnetorheological fluid with the shear rate. The Herschel–Bulkley model was corrected by fitting for the experimental results. The loading torque, calculated by the modified model, complied with the experimental results. This lays the foundation for the design of a high-speed transmission device based on the magnetorheological shear principle. Experiments of torque stability, temperature stability, and reusability verified the feasibility and accuracy of the proposed loading system. It provides a novel method to test the dynamic loading performance of high-speed motorized spindles.