With the invention of the many elements of nature applied to theory, that today define the extremities of engineering wonders, to create energy that gets to work, all the modern machines and systems, hydraulic energy is one name that is a successful force. In the modern world and a machine age, engineering sure takes all the demand in each sector. With the introduction of hydraulic energy, hydraulic pumps have become popular with their efficiency and simple mechanism. So what is a hydraulic pump and how does it work. It can be defined as a device that uses liquid to convert it to hydraulic energy, that can be used effectively to operate and manage many devices. The fluid when enters the pump, has a specific pressure and speed too. Once this fluids get displaced inside, the velocity and pressure increases, by the time the fluid reaches the outlet. These pumps are used on a wide platform in engineering and are available in various types. Most of them will have a slightly different mechanism, but use the same principle of work. So let us check some of the most common and efficient hydraulic pump types.
Types of Hydraulic Pumps
There are various types that rule the market. Some of them have excellent workings and mechanisms. Below are some of the common types of hydraulic pumps, with a little introduction on the work mechanisms of each pump.
These make the most common, easy to maintain and economical type of hydraulic pump. They fall in the positive displacement of fixed displacement category of pumps. They can be further classified in two types - internal gear and external gear. They use meshing of gears built inside the pump that push the fluid inside. Here the fluid gets displaced with the mesh, which builds the pressure, and then the fluid is sent through the outlet. These types of pumps are good for pressures below 200 bar, that is 3000 psi. Most of these pumps are noisy, however there are few varieties in the market that are efficient and less noisy too.
Gerotor pumps are similar to the gear pumps, these can be classified as a type of a variation of gear pumps. They are also a part of positive displacement pumps, and are included in the internal gear pumps. The rotor gear is in the inside of this pump, while the idler gear is on the external. Now, the rotor and the idler, create a suction for the fluid and act like a seal. Once inside the liquid travels through these gears and is then forced out through the outlet of the pump. These pumps are generally useful for applications that require low pressure. They are quite efficient and are moderately noisy.
As the name suggests, these pumps use screws as the main mechanism element. This is also a type of a positive displacement pump. Here the water travels through one or many screws. The fluid travels inside and gets rotated along with the axis of the screw, in between the threads of the screw. The rotor threads and the surrounding casing of the pump make a seal for the fluid from the inlet to the outlet. These pumps are the best for low pressure applications. They do not make much noise, but they may have certain disadvantages, specially in the field where churning of fluid is prohibited.
Bent Axis Pumps
These pumps are a part of both fixed and adjustable types of hydraulic pumps. They come in two designs that support each type. This pump uses a design that contains a rotating cylinder and two pistons that cover the cylinder radially. These pistons are placed at an angle, and are connected to the shaft and thrust plate. The shaft rotates with a specific mechanism and so do the pistols. The shaft rotates in an angle and the pistons are directed to reciprocate depending on the angular relativity of the shaft and the cylinder. It has some of the most efficient mechanisms and outputs.
Axial Piston Pumps
These pumps work very similar to the bent axis pumps. These are designed with a mechanism that helps in variable displacement of the fluid, that eventually helps in better control of pressure. This pump uses pistons, that are rotating and during half the rotation they suck the fluid, the rotation in the chamber of the pump creates the pressure in the fluid, after which in the next half of the rotation they let out the fluid to the outlet. These types of pumps have a smaller design but are very efficient and are more economical too.
Radial Piston Pumps
Radial pistol pumps work under high pressure and produce a smooth flow. They are generally fixed displacement pumps, but most of them also come in variable displacement options. The rate of fluid flow and the output velocity can also be changed with certain adjustment mechanisms. These are excellent for high pressure and have good strength.
Rotary Vane Pumps
These too make the most economical and reliable pumps. They are usually best options for a high flow but a low pressure output. They form the positive displacement pumps group. This pump contains vanes that are fixed and mounted onto a rotor that is on the inside of the cavity in the motor. The internal rotations maintain the pressure of the fluid.
These were the different types of hydraulic pumps, along with a little exposure of the mechanism of each. All these various types of pumps are used greatly in many sectors of industries and engineering. They truly stand as one big remark, as a stepping stone to brilliant engineering!