Gears

Gear is a mechanical device which transmits power. A small motor spins at a faster speed with enough of power. However gears are not with enough of torque. For instance more torque is required for turning a screw driver. A small motor give adequate power at high speed to turn the screw. The torque increases with decreased output speed. Gears are capable of adjusting rotation direction. Gear coupling major application is gear reduction. In general small gear is coupled with large gear to increase the torque. It happens at the expense of speed. Gear reducers are of two types namely larger gears are converted to smaller gears and the other slows velocity of input shaft. They are used according to function.

Basics

Gear ratio is the distance measured from the gear center and contact point when gear rotates. Ratio of gear changes with change in gear rotation. This ultimately changes the speed of gear. The acceleration and deceleration takes place as it is impossible to maintain the constant speed. Most of the modern gears utilize the tooth profile referred as involute. This involute helps in proper maintenance of constant profile of speed ratio that exists between two gears.

Types of gears

• Spur gears: Spur gears, common gear type has teeth mounted over the shaft.
• Helical gears: Helical gears device operation is smooth and quiet.
• Bevel gears: Bevel gears detect rotational direction of shaft.
• Worm gears: Worm gears find its own application in large gear production.
• Rack & Pinion gears: Rack and Pinion gear converts rotational movement in to linear movement. For instance steering system of car.

Questions:

• What are major forms of gear reducers?
• What are the types of gears?
• What is fixed gear bicycle?
• What are the advantages of gears?