mechanical system

Type of system in which mechanisms are joined together to achieve the transfer of motion. There are four basic types of motion that mechanisms carry out: linear motion (motion in one direction only); reciprocating motion (motion along a straight line in both directions alternately); oscillating motion (motion in an arc); and rotary motion (motion in a circle).

Different mechanisms give different types of motion: levers and linkages give linear motion; cams, cranks, and pistons give reciprocating motion; steering wheels, swings, and pendulums give oscillating motion; and wheels, pulleys, and gears give rotary motion.

Mechanical systems can be put together to change the motion from one type to another. They can also be combined to change the speed or direction of motion, and to alter the forces needed to operate the mechanical system. Bevel gears turn rotary motion through 90°. Rack-and-pinion gears, cams, or cranks can turn rotary motion into linear or reciprocating motion. Spur gears can be put together to alter the direction of rotary motion, and can make the system speed up or slow down. Pneumatic and hydraulic systems transfer movement, the former using air, the latter fluid, both of which are controlled by electrically or mechanically opened valves. Other ways of transferring motion include belts with pulleys and chains with gears.