Optimal design of planetary gearboxes for application in machine tools

Many machine tools are equipped with a motor-gearbox based on Planetary Gear Trains (PGT) to extend the constant power range of the machine tool spindle drive motor at low speeds. Other application of PGT in machine tools is for High Speed Machining (HSM). The use of a PGT transmission to approximate a conventional machine tool to HSM, providing an outstanding and cost-effective opportunity for upgrading an existing lower speed machine tool, can save substantial investment in new capital equipment. One of the cheapest solutions is the use of mechanical spindle speeders, used with proven performance in a variety of machining processes, such as drilling, milling, tapping and even grinding. In this paper the design of these PGT transmissions to extend the constant power range and for HSM are given. Results can be of great interest for manufacturers and engineers involved with the design of spindle drive gearboxes for machine tools.