The load-displacement capabilities of a mechanical press are determined largely by the design of its drive mechanism or, more precisely, the linkage through which the drive motor connects to the slide. This chapter discusses the primary types of linkages used and their effect on force, velocity, and stroke profiles. It begins by describing the simplest drive configuration, a crankshaft that connects directly to the slide, and a variation of it that uses eccentric gears to alter the stroke profile. It then discusses the effect of adding a fixed link, knuckle joint, or toggle to the slider-crank mechanism and how gear ratios, component arrangements, and other design parameters affect slide motion. The chapter also explains how to assess load and energy requirements, time-dependent characteristics, and dimensional accuracy and discusses overload protection, shutheight adjustment, and slide counterbalancing as well.

This chapter discusses the design and operation of electromechanical servo-drive presses. It begins by comparing the operating flexibility of servo-press drives with that of their conventional counterparts. It then explains the difference between direct-drive and belt and screw-driven servo presses and describes some of the innovations and improvements made possible with high-torque servo motors. The chapter provides examples of how servo presses are used in blanking, warm forming, and other applications and compares the operating characteristics of two 1100-ton presses, one driven by servo motors, the other by a mechanical crank.

This chapter discusses the design and operation of forging presses and hammers. It covers the most common types of presses, including hydraulic, mechanical, and screw presses, explaining how they work and comparing and contrasting their load and displacement profiles, stroke lengths, ram velocities, and energy and stiffness requirements. It also includes information on gravity- and power-drop hammers and where and how they are typically used.