Design of a Power Press (Machine Element Exercise: Only Calculations)

Problem: Design a power transmission system for a power press capable of forming/punching sheet metal for small industrial applications. The machine should be driven by an electric motor which supplies power to a crank shaft through an appropriately designed transmission system. The crank shaft should rotate at a speed of 65 rpm, and be able to deliver a maximum torque of 583 Nm. The power transmission system should include a V‐belt connected to a flywheel (to increase the operational stability of the machine), as well as a reduction gearbox of smallest possible size. The transmission system should be designed for a lifetime of 16585 operating hours. Requirements: 1. Determine the required power supply and select an appropriate induction motor from the manufacturer’s data sheet. 2. Select appropriate reduction ratios for the gear box and the belt drive. 3. Calculate the required rotary inertia of the flywheel to guarantee variations in rotational speed of less than 5% during operation. 4. Calculate the time required for the motor to reach the maximum rotational speed assuming zero torque on the shredder shaft. You may assume that the torque‐speed curve of the motor is bilinear. 5. Gearbox: a) Estimate the shaft diameters b) Calculate the major gear dimensions. c) Select appropriate materials for the shafts and the gear drive. d) Verify that the gears are safe against gear tooth bending and surface fatigue. e) Determine the size of appropriate keys and keyways. f) Verify that both shafts are safe against fatigue failure. g) Select rolling element bearings according to the required minimum lifetime. h) Provide a 2D drawing of the assembled gearbox (either by hand or CAD), including a bill of materials (BOM). One section through the center of the shafts is sufficient 6. Belt drive: a) Determine the size of pulley and flywheel. Provide a sketch of the flywheel with all major dimensions included. b) Calculate the required belt size and select an appropriate belt from the catalog.