Research And Development Of Circulating Ball Type Electric Power Steering Gear

With the increase of vehicle equipment weight and load-carrying capacity,the shortcomings of column electric power steering device C-EPS and mechanical cycle ball power steering device used in pickup trucks,light trucks and other models are gradually exposed.Because of the long chain between power source and actuator,C-EPS has many links resulting in low efficiency.The layout will be affected by other components in the cab,and the structure is complex,so the space cannot be used effectively.The bearing capacity and reliability of the mechanical cycle ball power steering device can not meet the needs of the steering system,and the life-cycle of the steering system and driving safety is reduced greatly.Therefore,it is necessary to design a new type of EPS system with large power,long life-cycle and high reliability to satisfy the need of large tonnage vehicles'steering system.This paper design the circulating ball electric power steering B-EPS for Shifeng Juxing? series agricultural trucks.The integrated design of B-EPS that the power source is also the executive component improve the work efficiency and simplify the structure.The assist characteristics of the B-EPS steering gear were studied and designed to obtain the assist characteristic curve.The steering follow of the power system was verified that it could provide the optimal power under various driving conditions.The designed mechanical structure of the steering system improves the load-carrying capacity and service life,and optimizes the space layout of the vehicle.Finally,the key parts of the steering system are analyzed by using finite element method,including strength analysis,life analysis and modal analysis,and the prototype is made.