A mechanical approach of overload protection mechanism for a heavy truck wheel force transducer

The wheel force transducer (WFT), which measures the force or torque applied to the wheel, is an important instrument in vehicle testing field and has been extremely promoted by researchers. Since the high cost and technical secret of the commercial products may slow down the development of WFT to some extent, Southeast University has devoted to the WFT research with some prototypes. Essentially, the WFT is a multi-axis force sensor (MFS) in which an elastic-body will deform under the applied forces. However, when applying a MFS into vehicle wheel and making it to be a WFT, it may be subjected to forces/moments which exceed the measuring range under the over rated load, especially on a heavy truck WFT under loads of X or Z direction. Plastic deformation and damage may occur on the elastic-body of WFT. This paper presents a mechanical approach of the overload protection mechanism which can prevent the overload damage and guarantee the sensor performance. An intermediate flange, which is elaborately designed using Computer Aided Engineering (CAE) tools, is installed between wheel hub and the elastic body to meet the overload protection. Experiment and prototyping test are conducted on the hydraulic platform. Results show that the proposed overload protection mechanism performs well. In particular, the applied loads over ±120 kN and ±30 kNm are prevented from damage for the heavy truck WFT.   Key words: Wheel force transducer, overload protection mechanism, vehicle wheels/typres, heavy duty trucks.