Simple mechanisms. Lifting mechanism. Simple mechanisms in everyday life

From the very antiquity a person tries to facilitate his work. To do this, he uses various devices. What are the simplest mechanisms? What are the varieties of these adaptations? What is the difference between simple and complex mechanisms? About this and much more - later in the article.

general information

Simple mechanisms (from the Greek "machine, gun") - devices that give a gain in strength. Some of these devices appeared in ancient times. Simple mechanisms can be independent devices or be elements of more complex aggregates. Depending on the type of construction is determined and the scope of a particular device. The use of simple mechanisms greatly facilitates human activity. Such devices give a gain in strength. For example, the wedge, which is driven into a log, has more power than the impact on the device itself. Therefore, the tree quickly bursts in different directions. Along with this, the impact on the wedge falls from the top down, and parts of the log are moved apart. That is, in this case, there is also a transformation in the direction of motion.

Simple mechanisms. Examples

There are several types of devices:

Inclined plane

A) the screw is used in screws, like a drill in jackhammers, drills; Can serve as a lifting mechanism (Archimedov screw) ;

B) the wedge helps increase pressure by concentrating the mass in a small area. It is used in a pool, shovel, spear.

Lever - the device described by Archimedes. Can act as a trigger, switch.

A) the gate is used for belt transmission and raising water from the well.

The wheel (invented in 3 thousand BC by the Sumerians) is an integral part of the gear system used in transport.

The piston facilitates the use of the energy of heated expanding gases or steam. This device is used in steam engines and firearms.

Gate

This device is a drum (cylinder), to which the handle is attached. As a rule, it was used as a lifting mechanism for lifting water from a well. The winning in the force that is obtained when using the gate is determined by the ratio of the radius of the circumference on which the handle moves, to the radius of the cylinder (drum) on which the rope is wound. The winch belongs to the modern type of the gate. This device is a system comprising a cylinder and two gears of different radii. The win in force, which in general gives the winch, is determined by the combined action of the two gates. Modern devices give a gain of forty-one hundred times.

Inclined plane

This simple mechanism is also often used when lifting heavy bodies. The gain in force is determined by the ratio of the length of the device itself to its height under the condition of low friction. Often, to create a large force (for example, for the operation of an icebreaker or for chopping firewood) use the form of an inclined plane - a wedge. Its action is based on the fact that, with a large force in the direction of the shoe, large forces perpendicular to the lateral surfaces of the device are formed. Another type of inclined plane is the screw. Just like the wedge, this device is able to change the direction or numerical value of the applied force.

Simple mechanisms. Lever arm

It is a solid body that can rotate around a support (fixed). The smallest distance that separates the fulcrum and the straight line along which the force acts on the lever is called the shoulder of force. To find it, it is necessary to drop the perpendicular from the fulcrum to the force action line. The length of this perpendicular will be the shoulder. F1 and F2 - acting on the lever force. The shoulders acting on the device are L1 and L2. The lever then is in equilibrium, when the forces acting on it are inversely proportional to the shoulders. This rule can be represented as a formula: F1 / F2 = L1 / L2. This principle was established by Archimedes. This rule shows that a greater force with a lever can be counterbalanced by a smaller one. The force applied to one shoulder is so many times greater than that applied to the other, as much as one shoulder is greater than the second.

How does a person apply today?

Very common simple mechanisms in everyday life. So, it would be difficult to open a water tap if it did not have a small handle that is a fairly effective lever. The same can be said about the spanner, by means of which the nuts or bolts are untwisted or twisted. The longer the handle, the easier it will be to perform the action. So, when working with heavy or large nuts and bolts for repairing complex machinery, machines, cars, use keys with handles up to one meter in length. The most common door is also one of the types of devices considered. If you try to open the door near its fastening, it will be very difficult. However, the farther from the hinges the handle is, the easier it is to open the door. A vivid example is a pole vault. Its length is about five meters. With this lever and properly applied effort, the athlete manages to fly to a height of up to six meters. The long shoulder is about three meters. Leverages are also found in different parts of the human body and animal body. This, in particular, jaws, limbs. Household examples of the lever are nippers, scissors for cutting metal or paper. Machines of various types have in their design also devices that allow you to obtain a gain in strength. For example, pedals or handbrake on a bicycle, handles sewing machines, keys in the piano.

Complex application of tools

Simple mechanisms are found in a variety of combinations. Combined devices include two or more parts. Not necessarily this will be a complex mechanism - many simple devices can be considered complex. So, in the meat grinder there is a handle (gate), meat pushing screw and knife-cutter (wedge). In the wristwatch, the arrows are rotated by means of a system of gears having different diameters and located with each other in the clutch. One of the known combined simple mechanisms is the jack. It uses a combination of a gate and a screw.

Conclusion

As it became clear, simple mechanisms greatly facilitate human labor. They can consist of one or more parts. In this case, even if there are two or more elements, they can remain simple, but they can be quite complicated. Various aggregates, printing presses, engines include several parts. Among the elements there are levers, blocks, screws, wheels on the axes, inclined planes, a wedge. All these devices work in a complex. Thanks to them, a person makes work much easier. The transfer of mechanical energy from one part of the device to another can be carried out in different ways. Chains, belts, gears or cogwheels are considered to be the most common devices contributing to the transmission of force and causing individual elements to move more slowly or faster in one direction or another. Complex and high-speed devices are controlled, as a rule, by electronic devices. Due to the special configuration, the electric sensors show when it is necessary to turn on this or that mechanism, also follow the correct and stable operation of the system. Many devices have come to modern life from ancient times. People are constantly improving complex mechanisms, thus expanding the scope of their application. Undoubtedly, in the everyday life of a person, various devices occupy a very important place. Much can not be imagined without the use of simple and complex mechanisms. Adaptations are widely used in construction, agriculture, mining and other areas of human activity.