A wheel and axle machine is an arrangement of a round disc and a cylindrical rod in such a way that the disc covers the rod from the outside. Depending on the nature of the effort or the force applied to the wheel or the axle, the load gets deformed in shape or gets displaced from its position. A wheel and axle simple machine represents a type of lever where the axle acts as the fulcrum or the balance point. The first wheel and axle simple machine was a type of potter’s wheel introduced by the people of Mesopotamia around 3500 B.C.
Types of Wheel and Axle Machine
Depending on the point or the spot where the force is applied, wheel and axle machines can be classified into two broad categories given below:
1. Machines where force is applied to the axle
Here, the effort or the force is applied to the axle that causes the wheel to rotate at a rapid rate. This means that the motion initiated by the axle gets transferred to the wheel. Some of the real-life applications that use this type of wheel and axle simple machines include bicycle, Ferris wheel, etc.
2. Machines where force is applied to the wheel
In these types of machines, the effort or force is applied to the wheel, causing it to rotate. The motion of the simple machine is initiated by the wheel that builds a significant amount of pressure on the axle. Some of the examples of such machines include pizza cutter, windmill, drill machine, etc.
Examples of Wheel and Axle Machine
A bicycle consists of an arrangement of wheel and axle that helps it move forward. Here, the force applied to the axle initiates the motion and causes the wheels of the cycle to move.
2. Car Tires
The tires of a car move forward or turn to either side with the help of an axle. When the engine of the car exerts a force on the axle, the wheels tend to move or rotate accordingly.
3. Ferris Wheel
You must have observed a Ferris wheel in an amusement park. It consists of a giant wheel that rotates in a circular direction. The centre point of the Ferris wheel consists of a cylindrical rod known as the axle. The axle is subjected to a high magnitude electrical force, which supports the rotation of the Ferris wheel.
4. Electric Fan
The blades or the wings of a fan are attached to a hub. The hub is further connected to a motor with the help of an electric circuit. The force generated by the motor reaches the hub and helps the blades of the fan rotate. Here, the hub of the fan acts as the axle, and the blades represent the wheel. Hence, an electric fan is a prominent example of a wheel and axle simple machine.
5. Analog Clock
An analogue clock is yet another example of a wheel and axle simple machine. The minute, hour, and second hands of a clock are attached to the centre to a cylindrical pin. This cylindrical pin acts as the axle, and the hands of the clock represent the wheel. The rotation of the hands takes place when the force is applied to the cylindrical pin. Hence, an analogue clock is an example of a wheel and axle simple machines.
A windmill consists of rotary blades attached to the top of a pole. The top of the pole acts as the centre point or the axle. When the high velocity of winds cause the blades to move, a considerable amount of force gets exerted on the axle, thereby making the windmill a prominent example of wheel and axle machines.
7. Pizza Cutter
A pizza cutter consists of a movable cutter wheel. A handle is attached to the centre of the cutter with the help of an axle pin. When the force is applied to the wheel, it tends to move, thereby creating pressure on the axle. Hence, a pizza cutter is a classic example of a wheel and axle simple machine.
In a drill machine, a metallic drill bit is attached to the spindle. A force is exerted by the internal circuitry of a drill machine to the axle or the spindle that causes the bit to rotate. The rotation of the bit can be further used to groove holes in rigid surfaces. Hence, a drill machine is the example of a wheel and axle simple machines in which the force is exerted on the axle that causes the wheel to move or rotate.
9. Door Knob
A door knob closely resembles the wheel and axle simple machine. Here, the doorknob acts as the wheel, and the shaft present at the centre of the knob functions as the axle. When the knob is turned, a force is built on the shaft or the axle. This force helps retract the latch and open or close the door with ease.
10. Water wheel
A water wheel makes use of the kinetic energy possessed by the flowing water to generate energy. The working of a water wheel is quite similar to that of a windmill. It consists of a huge wheel attached to an axle in the centre. The paddles of the wheel rotate with the help of the flowing water. The motion or rotation of the wheel exerts a force on the axle, which can be used further to produce energy.