API Q1 Spiral Bevel Angle Gearbox for Onshore Drilling Drawworks Power Transmission Angle Gearbox The angle gearbox is driven by a pair of vertical bevel gear pairs, and its input end is connected with the output end of the transfer case through the transmission shaft, and then the power is output to the drawworks through the sprocket mounted on the output shaft after changing direction through the bevel gear. The angle gear box is mainly composed of input shaft, output shaft