The invention discloses a structure and a method for improving performance of a
recirculating ball steering gear for a
commercial vehicle, and the structure is characterized in that a gradual change correction structure is arranged in a range of + / -150 degrees in the middle position of a steering screw rod and is divided into three correction intervals, a high
friction torque area is formed through middle
diameter local drum shape correction, and the middle
position control precision is improved; a
pitch line of a tooth groove of a middle tooth of the steering nut is lifted by 0.1-0.3 mm relative to
pitch lines of teeth on the two sides, so that the meshing rigidity is enhanced; the middle tooth area of the
rocker arm shaft is provided with a subarea gradual change correction structure, so that the meso-position meshing characteristic is clear and the
wear resistance is high; according to the method, a
grinding or tooth profile milling process is adopted to achieve accurate correction of a steering screw raceway and a steering nut tooth groove, and through
collaborative design and parameter matching of a steering screw, a steering nut and a
rocker arm shaft, the comprehensive performance of a whole vehicle
steering system in the aspects of
neutral position controllability, aligning performance and durability is optimized; the problems that a traditional
recirculating ball steering gear is fuzzy in
neutral position, stiff in control, large in return residual angle and the like are effectively solved.