强度条件 即 W 1.等截面圆轴：(W为常量) 2.阶梯形圆轴： Me3 620Nm 780N-m 1400Nm Me3 (+) 620Nm 1400Nm Mel [小 W (p)1. 等截面圆轴:(Wt 为常量) 2. 阶梯形圆轴： 强度条件 τ τ max ≤ [ ] max [ ] t T W 即 τ τ = ≤ [ ] max max t T W τ τ = ≤ max ( )max [ ] t T W τ τ = ≤