外文原文: Mechanism and Machines A system that transmits forces in a predetermined manner to plish specific objectives may be considered a machine. A mechanism may be defined in a similar manner, but the term mechanism is usually applied to a system where the principal function is to transmit motion. Kinematics is the study of motion in mechanism, while the analysis of force and torques in machined is called dynamics. Once the need for a machine or mechanism with given characteristics is identified, the design process begins. Detailed analysis of displacements, velocities, and accelerations is usually required. This part of the design process is then followed by analysis of force and torques. The design process may continue long after first model have been produce and include redesigns ponent that affect velocities, accelerations, force, and torques. In order to pete form year to year, most manufacturers must continuously modify their product and their methods of production. Increases in production rate, upgrading of product performance, redesign for cost and weight reduction, and motion analysis of new product lines are frequently required. ess may hinge on the correct kinematic and dynamic analysis of the problem. Many of the basic linkage configurations have been incorporate into machines designed centuries ago, and the term we use to describe then have change over the year.
