Gear Design

A 17-tooth 20° pressure angle spur pinion rotates at 1800 rev/min and transmits 3 kW to a 52 tooth disk gear. The module of the gear is 2.54 mm, the face width 40 mm, and assume the suitable quality standard for the gear. The gears are straddle-mounted with bearings immediately adjacent. The pinion is a grade 1 steel with a hardness of 240 Brinell tooth surface and a through-hardened core. The gear is steel, through-hardened also, grade 1 material, with a Brinell hardness of 200, tooth surface and core. Poisson's ratio is 0.30 and Young's modulus is 205 MPa. The loading is smooth because of motor and load. Assume a pinion life of \(10^8\) cycles and a reliability of 0.90, and use \(Y_N=1.3558N^{-0.0178}\), \(Z_N=1.4488N^{-0.023}\). The tooth profile is uncrowned. This is a commercial enclosed gear unit. Find the factors of safety of the gears in bending. Find the factors of safety of the gears in wear. By examining the factors of safety identify the threat to each gear and to the mesh.

A 15-tooth spur pinion has a module of 3 mm and runs at a speed of 1600 rev/min. The driven gear has 60 teeth. Find the speed of the driven gear, the circular pitch, and the theoretical center to center distance.

A commercial enclosed gear drive consists of a 20° spur pinion having 16 teeth driving a 48 tooth gear. The pinion speed is 300 rev/min, the face width 50 mm, and the module 4 mm. The gears are grade 1 steel, through hardened at 200 Brinell, made to No. 6 quality standards, uncrowned, and are to be accurately and rigidly mounted. Assume a pinion life of \(10^8\) cycles and a reliability of 0.95. Determine the AGMA bending stress and the corresponding bending factors of safety if 4 kW is to be transmitted.