Electromagnetic Couplings and Brakes Quiz

Reduction Gears

• A small gear called a pinion is driven by the incoming engine shaft, directly driving a large gear mounted on the propeller shaft.
• The speed is adjusted by making the ratio of the speed reduction to the diameter of pinion and gear proportional.

Single Reduction Gear

• A single gear assembly has a gear double the size of a pinion.
• The arrangement consists of only one pair of gears.
• The reduction gear box consists of ports through which the propeller shaft and engine shaft enter the assembly.

Double Reduction Gear

• Double reduction gears are used in applications involving very high speeds.
• The pinion is connected to the input shaft using a flexible coupling.
• The pinion is connected to an intermediate gear (first reduction gear) which is then connected to a low-speed pinion with the help of one more shaft.
• This pinion is connected to the second reduction gear mounted directly on the propeller shaft.
• Such an arrangement facilitates the reduction of speed to a ratio as high as 20:1.

Electromagnetic Couplings

• An electrically generated magnetic force ensures connection between the armature and rotor in an electromagnetic coupling.
• If the voltage disappears, the magnetic field is removed, and the pre-stressed spring will separate again the armature and rotor.
• Electromagnetic couplings are used in systems such as electromagnetic brakes, electromagnetic pull/push, electromagnetic clutches, electromagnetic vibrators, and reduction gear drives.

Reduction Drives

• Reduction drives are used in engines of all kinds to increase the amount of torque per revolution of a shaft.
• Examples of reduction drives include the gearbox, differential, and steering boxes of any car.