| 【文章摘要】 This study investigates the strength of plastic helical wheels meshed with enveloping and cylindrical worms whose tooth profiles mesh in line contact with helical wheels.R unning fatigue tests of plastic helical wheels together with a conventional cylindrical involute worm,a line contact enveloping worm,and a line contact cylindrical worm were conducted.T he tooth bearings,tooth temperatures,and fatigue lives of plastic helical wheels meshed with the different worms were examined at various center distances.Main results obtained are as follows:T he lives of both line and point contact wheels depended upon backlash,but the lives of line contact wheels are more sensitive to backlash than those of point contact wheels.At the backlash that maximizes the wheel life,the line contact wheels last longer than point contact wheels at smaller applied torques,but the influence of worm type on wheel life reduced at higher applied torque. |