Structure Design And Optimization Of In-wheel-motor Housing Of Knuckle Type

The in-wheel-motor vehicle has the characteristics of compact structure,high transmission efficiency,flexible layout of the entire vehicle,and independent drive control.It is an inevitable trend for the development of electric vehicles,and it has begun to enter the stage of industrialization.However,it is still faced with problems such as in-wheel space limitations,difficulties in integration of in-wheel-motor and suspensions,and increased unsprung masses.In this paper,the in-wheel-motor and the knuckle are designed in a fusion design and the key component,the in-wheel-motor housing of knuckle type is designed.It solves the problem of component connection in a limited wheel space and realizes the lightweight of in-wheel-motor.The specific work of the full text is as follows:(1)The characteristics of the in-wheel-motor and suspension were fully analyzed,and the integrated design of the in-wheel-motor and the steering knuckle was completed.The structural design of the key component,the in-wheel-motor housing of knuckle type,was completed.(2)The in-wheel-motor suspension performance optimization was completed.The McPherson suspension's motion analysis model based on the instantaneous screw axis method was established to analyze the suspension performance and determine the optimization goals.Apply the Adams/Insight module to determine the optimal design variables.A multi-objective optimization model based on NSGA-II algorithm was established to optimize the suspension performance.The optimized suspension performance meets the design criteria and a reasonable in-wheel-motor housing of knuckle type's structure parameters were obtained.(3)Six typical driving conditions of the in-wheel-motor vehicle were determined,and the tire ground force calculation was completed.A coordinate transformation model was established to complete the transformation of the hard point position to the hard point position in the local coordinate system under the vehicle coordinate system.The load analysis model of the in-wheel-motor housing of knuckle type was established and the calculation of the load of the in-wheel-motor housing of knuckle type was completed.(4)It was determined that the material of the knuckle type hub motor housing is ZL101 aluminum alloy.The strength analysis and modal analysis of the in-wheel-motor housing of knuckle type under six typical driving conditions were completed.The results showed that the structure has obvious stress concentration under various driving conditions,but the average stress level was low,and the material was wasted;the first-order free modal frequency of the structure was 969 Hz,which was greater than the excitation frequency.(5)A topology-optimized SIMP material interpolation model was established and the optimization strategy was deduced.The topology optimization of the in-wheel-motor housing of knuckle type was completed and the verification of the reconstruction model was completed.The results show that the optimized structure eliminates the stress concentration phenomenon,the maximum stress difference under various driving conditions was reduced,and material waste was effectively avoided;the first-order natural frequency increased by 22.6%,the structural weight reduced by 30.9%,and the optimization effect was obvious.