The wheel and axle, pulley, inclined plane, screw, wedge, and lever are all examples of simple machines that are commonly utilized. While basic machines can amplify or diminish the forces that can be applied to them, they have no effect on the overall amount of effort required to complete the activity. Examples include the water-powered mill where the force of water moving through the mill goes into driving the drum which in turn drives the shaft attached to the drum, or the windmill where the force of the wind acting on the blades of the windmill is used to drive a shaft which in turn drives a machine such as a hand mill or pump.
Simple machines can be used to reduce energy costs for more complex machines. For example, a motor/generator runs on electricity which is produced by either fossil fuels (brought up from the ground) or nuclear power (produced by splitting atoms). The motor/generator takes the mechanical energy from the rotating shaft and turns it into electrical energy which can then be used by other devices. This reduction of energy cost can be very significant for large systems such as those found in power plants.
Also, simple machines can be used to create force multiplication effects. For example, if you connect several wheels together with axles then you have created a polygonal chain structure.
Simple machines are beneficial because they decrease effort or allow individuals to execute activities that are beyond their typical skills.
Even though they are simple, simple machines can do a lot of work for us. They are used in many applications including construction, manufacturing, farming, mining, and transportation. Understanding how these machines function is important for us to use them effectively in our daily lives as well as in engineering projects.
Simple machines have been very useful since ancient times. The ancients discovered ways to utilize certain natural objects that we now know are simple machines. For example, the lever was first used by man around 3000 B.C. at the Great Wall of China to lift heavy stones for building his shelters.
In modern times, scientists have also invented new simple machines. In 1799, Thomas Jefferson invented the parallel bar which functions based on the principle of levers. In 1811, Sir Hugh Myddleton developed the centrifugal pump which uses force applied to a fluid by rotating parts to produce a flow.
Simple machines will be discussed in more detail in future posts.
Machines can be basic, consisting of only one or a few pieces. Simple machines include the inclined plane, wedge, screw, lever, wheel and axle, gear, and pulley. Many machines are made up of multiple basic machines. These complicated devices assist humans in performing activities that are tough, repetitive, dangerous, or simply dull. Examples include cranes, bulldozers, and earthmovers. Other machines use alternative methods for providing power without using motors; these include electricity, compressed air, and hydraulic pressure.
Screws are mechanical devices used to transform rotary motion into linear motion. They can be used to lift heavy objects or to produce an extremely strong force along with some degree of directional control. Screws are often used in machinery because they allow easy transmission of power from a motor to the load. However, screws can also be hand operated by someone using a tool called a screwdriver. This section covers the basics of how screws work, including their types, functions, applications, and advantages/disadvantages.
Screws are usually designed as either straight or helical. A straight screw has a smooth, even thread while a helix has a series of peaks and valleys. Most common screws are straight. Helical screws are used mostly for fine, precise work where even small amounts of movement between the screw and its hole are not acceptable. Some examples of helical screws include toilet bowl brushes and sewing machine feet.
A machine with minimal or no moving components that is used to facilitate work (and provides a mechanical advantage). A wedge, wheel and axle, lever, inclined plane, screw, or pulley, for example. Machines are useful because they can do work that humans cannot. With a machine, the hard job is done by the machine while you sit around doing nothing. Humans are good at doing nothing, so this is how most machines have evolved over time.
All machines consist of two parts: 1 a mechanism that produces the effect you want, and 2 a device that uses energy to operate the mechanism. For example, a wheel and axle system operates on the principle of inertia. That is, any object in motion will stay in motion unless an external force acts upon it. The force needed to stop this movement is called "drift" and is defined as the weight of the vehicle divided by its diameter. As long as this ratio is less than one, the vehicle will keep rolling. If it is greater than one, the vehicle will come to a halt after some distance has been covered.
Simple machines can be further divided into two main types: hydraulic and mechanical. Hydraulic machines use fluid pressure to actuate their mechanisms whereas mechanical machines use the interaction of rigid bodies for this purpose. For example, a crane is a mechanical machine since it uses steel beams and wheels to move objects about.
They are the most basic systems known for increasing force by leverage (or mechanical advantage). The inclined plane, lever, wedge, wheel and axle, pulley, and screw are examples of basic machines. Six straightforward devices for converting energy into work. And four ways of making work easier.
Inventors have been improving on these basic designs since they were first proposed in the 17th century. Some modern inventions include: hydraulic presses; electric motors; and gearboxes and axles. All help make work easier to perform.
How has technology improved machinery? Technology has provided inventors with a large selection of high-quality materials that are essential for creating more efficient machines. For example, engineers use steel instead of iron because it is stronger and lighter than its counterpart. The same goes for other common machine components such as aluminum, copper, and plastic. Modern technology also allows for precision parts that used to be impossible to make. A computer controlled milling machine can carve nearly any shape out of metal, while a human operator could only do a few at a time with a hand drill.
Has technology made work harder to do? Yes. Computers are great for calculating large amounts of data quickly, but they can't replace people who do things manually. Even after years of development, robots cannot match the dexterity of humans.