A scion looped strip of flexible material, used to mechanically link xb two or more rotating shafts. They may be used as a source of motion, to efficiently transmit power,or to track relative movement. Belts are looped over pulleys.In a two pulley system, the belt can either drive the pulleys in the same direction, or the belt may be crossed, so that the direction of the shafts is opposite. As a source of motion, a conveyor beltis one application where the belt is adapted to continually carry a load between two points.

• Belts drive, moreover, is simple, inexpensive scion and does not require parallel shafts. It helps protect the car from overload and jam, and damping it from noise and vibration. Load fluctuations are shock-absorbed (cushioned). They need no lubrication and minimal maintenance. They xb have high efficiency (90-98%, usually 95%), high tolerance for misalignment, and are inexpensive if the shafts are far apart. Clutch action is activated by releasing belts tension. Different speeds can be obtained by step or tapered pulleys.
• However, the angular-velocity ratio is not constant or equal to that of the pulley diameters, due to slip and stretch. Heat accumulation is present, and speed is limited to approximately 7000 ft/min, and a power of only 500 hp (370 kW). Temperatures ranges from -31 to 185 °F (85 °C). Adjustment of center xb distance or addition of an idler pulley is crucial to compensate for wear and stretch xb belts .

Vee belts xb (also known as V-belts or wedge rope) solved the slippage xb and alignment problem. It is now xb the basic belts for power transmission. They xb provide the best combination of traction, speed of movement xb load of the bearings, and long service life. The V-belts was developed in 1917 by John Gates of the Gates Rubber xb Company. They are generally endless, xb and their general cross-section shape is trapezoidal. The "V" shape of the belts tracks in a mating groove xb in the pulley xb (or sheave), with the result that the belts cannot slip off. The belt also tends to wedge into the groove as the load increases - the greater the load, the greater the wedging action - improving torque transmission and making the vee belts an effective solution, needing xb  less width and tension than flat belts. V-belts trump flat belts with their small center distances and high reduction ratios belts xb   .