Mechanical Motion Transformation Systems Explained

Mechanical Motion Transformation Systems

Rack and Pinion Mechanism

The rack and pinion mechanism has two parts: the rack, which is a straight bar, and the pinion, which is a gear. Both have teeth that interlock. When the pinion rotates, the rack moves. If the mechanism is reversible, the pinion also rotates when the rack moves.

Nut and Bolt Mechanism

This mechanism has two parts: a bolt with a spiral groove and a nut that turns around it.

• When the bolt is stationary, the nut rotates and moves along the bolt. This is used to fasten different parts together.
• When the bolt is mobile, it moves through the nut. We use this to lift loads.

Winch and Crank Mechanism

A winch is a cylinder that rotates around a horizontal axis. We attach a rope to a winch and to a load. Then, we turn the crank to rotate the winch. This crank increases the force, and the rope rolls up around the winch, lifting the load. The increase in force is proportional to the ratio between the radius of the crank and the radius of the winch.

Reciprocating Linear Motion Transformation

These mechanisms are used when motor movement is restricted. Some mechanisms work in the opposite way, transforming rotary motion into reciprocating linear motion.

Crank and Rod Mechanism

The mechanisms that produce movement in the bicycle and train are the same. For example, the train wheels and the pistons of the steam engine move the rods forward and backward. Rods move back and forth (alternating linear movement), while cranks move round and round.

Crankshaft Mechanism

The crankshaft mechanism is composed of multiple rods that are connected to one rotational axis. The rods are connected to cranks, which are connected to the crankshaft. A crankshaft mechanism can synchronize the movements of various parts.

Cam Mechanism

A cam rotates on a shaft and pushes a special bar called a follower. An eccentric cam is a disc with its axis of rotation positioned off-centre. This means the cam has two radii of different lengths. As the cam rotates, it makes the follower rise and fall.

Motion Control Mechanisms

Ratchet

The ratchet mechanism controls the direction of motion. It allows motion in one direction but not in the other. Some ratchets are reversible, so they can tighten or loosen things in two directions.

Speed Reduction

Brakes

Brakes are mechanisms designed to reduce speed. They use a device that presses against the moving wheel to create friction. There are various types of brake systems according to where the friction is produced. All brakes are activated by some type of lever. The lever transmits force to an output receptor, which puts pressure on the wheel. This produces friction, which slows down the wheel.