Mechanical Gear Systems: Types and Applications

Gear Mechanisms and Cogwheels Explained

Cogwheels are sets of wheels that have teeth, often called cogs. These teeth fit into the spaces between the teeth of another wheel, allowing one wheel to move the other. They transmit rotary motion between two connected axles, which can be parallel, perpendicular, or oblique. Gears can be cylindrical or conical, and all teeth must be the same shape and size. The two wheels and their corresponding axles rotate in opposite directions.

In this system, N1 and N2 represent the velocities of the corresponding wheels, while Z1 and Z2 are the numbers of teeth. The ratio Z1/Z2 is known as the gear ratio.

Uses:

• Industrial machinery
• Vehicles
• Domestic appliances (e.g., drills, food processors)

Worm Gear Systems: Function and Applications

A worm gear consists of a screw that moves a helical cogwheel, which is set perpendicular to the screw. Each time the screw rotates, the gear advances by as many teeth as there are grooves in the screw, typically a small number (e.g., 1, 2, or 3). This mechanism is primarily used to reduce velocity and also functions effectively as a brake system.

Here, Nwheel and Nscrew denote the velocities of the wheel and the screw, respectively. Zgrooves is the number of grooves on the screw, and Zwheel is the number of teeth on the wheel.

Uses:

• Lap counters
• Gear reduction systems
• Musical tuning keys
• Windscreen wipers

Chain Drive Gear Mechanisms and Their Uses

Chain drive gear mechanisms involve two cogwheels with parallel axles positioned a certain distance apart. They rotate simultaneously by means of a metal chain or a toothed belt stretched over both wheels. The chain transmits the rotary motion from axle 1 to axle 2 via gears 1 and 2, and importantly, both gears rotate in the same direction.

This system efficiently transmits greater forces without losing velocity because the chain is securely attached to the gear teeth, preventing slippage between the chain and the wheel. The formula for calculating the ratio between the rotation velocity of the drive wheel and the driven wheel is the same as for a standard gear mechanism.

N1 and N2 are the velocities of the corresponding wheels, and Z1 and Z2 are the number of teeth.

Uses:

• Industrial machinery
• Engines and motors
• Bicycles
• Motorbikes
• Three-wheeled vehicles

Gear Train Systems: Principles and Applications

A gear train is a system comprising more than two gears connected together. The rotary motion of the first wheel drives the second wheel, and so on, transmitting power through the series. In such a system, the rotary motion of the first axle is transmitted to the second by means of wheels 1 and 2. Wheel 3 rotates with the same velocity as wheel 2 and drives wheel 4, to which it is connected. Each connected gear rotates in the opposite direction to the gear it is attached to.

N1 and N4 represent the velocities of the drive wheel and the driven wheel, respectively. Z1, Z2, Z3, and Z4 are the number of teeth on the respective wheels.

Uses:

• Machine tools
• Robotics
• Vehicle gearboxes
• Some electrical appliances