Traditionally, when we talk about motors, we usually refer to internal combustion engines or electric motors. However, there are other types of motor. Among these types of motor there are the physical power motors.
The so-called physical power motors are motors that take advantage of the kinetic energy or the potential energy of some element.
An example of power motors is found in hydro power plants. In this type of installation the potential energy of the water is used, which, when it falls, becomes kinetic energy and activates a turbine. In this way, a motor, in this case a generator, performs an energy transformation: from kinetic energy to electrical energy.
Another power source of power engines is the use of compressed gases. In this classification we find the pneumatic motors .
The physical power motors are used in multiple applications. These engines are used in some funiculars, cable cars and even in watchmaking. Some watches have a weight that falls under gravity.
The pneumatic motor is a type of power motor that works by means of a compressed gas.
The pneumatic motors deliver a movement with pneumatic energy. This can be either a rotary movement or a linear movement. When it is a rotating movement, it is delivered to an axis.
An example of a linear pneumatic motor is the pneumatic drill , that is, a pneumatic drive chisel that is used to break a road surface when working.
The operation of a pneumatic motor is carried out with compressed air through a compressor.
Pneumatic motors offer an important advantage over electric motors, since they can not cause sparks and, therefore, are suitable for working in areas with risk of explosion.
Air motors are often used in machine shops to ensure bolts and nuts.
A hydraulic motor has the function of converting hydraulic energy into mechanical work. There are a variety of designs of hydraulic motors. These designs are classifiable in terms of their operation in constant and variable engines.
Hydrostatic units have a fixed relationship between volume flow and speed, but they can be changed. They are built as hydraulic pumps (for example, as a gear pump); The energy transported by the flow of oil is converted into rotation energy by the action of the pressure in the gears.
The designs of axial piston engines are available with constant and variable stroke volumes. They are used, for example, as a driving line for excavators; in this context, a hydrostatic transmission is often used.
The torque generated by the hydrodynamic motors is often controllable regardless of the speed.
The maximum torque of a hydraulic motor is determined by the hydraulic fluid pressure. The displacement determines the speed, depends on the volume flow supplied.
Advantages and disadvantages of the hydraulic motor
Hydraulic motors are used in engineering much less frequently than electric motors, but in some cases have significant advantages over the latter. The hydraulic motors have 3 times less volume and weigh 15 times less than the corresponding electric motors.
The range of control of the rotation speed of a hydraulic motor is much wider: for example, it can be from 2500 rpm to 30-40 rpm and, in some cases, for special hydraulic motors, it reaches 1-4 rpm or less.
The start and acceleration time of the hydraulic motor is a fraction of a second, which is unattainable for high-power electric motors (several kilowatts). For the hydraulic motor , there is no danger of frequent stops and reversals. The law of movement of the motor shaft can be easily changed using the means of regulation of the hydraulic drive.
However, the motors have the same disadvantages inherent to the hydraulic drive.