Hydraulic drive systems are the areas where Hydraulic Pump is widely used. It can be hydrodynamic or hydrostatic. These pumps are mechanical sources of power that will convert the mechanical power into the available hydraulic energy. It generates enough flow to overcome pressure otherwise induced by load at the pump outlet.

The hydraulic pump helps in creating a vacuum at the pump inlet, which will force liquid from the reservoir into the inlet line to the pump. The mechanical action in here helps in delivering liquid to pump outlet and into the hydraulic system.

These pumps are positive displacement options, while the hydrodynamic ones are fixed displacement pumps. It will have a more complicated construction to allow displacement to be properly adjusted. These pumps are frequent in daily use. These pumps mainly work on Pascal’s law.

Classification of the pumps

The pumps are mainly divided under two major belts, which are non-positive displacement and positive displacement. The pumps used in the hydraulic systems fall under positive-displacement.

Pump typesDescription
Non-positive displacementIt helps in producing continuous flow. But, it will not provide a positive internal seal, otherwise placed against slippage. So, the output varies considerably with varying pressure. Propeller pumps and centrifugal ones are some examples.
Positive displacement pumpsHere, the slippage remains negligible when compared to the volumetric output flow of the pump. In case, the ports are plugged, the pressure will get to increase to such a point where the pumping element might fail, or the prime mover of the pump would stall.

Stages and types of hydraulic pumps and their designs

There are mainly three major types of hydraulic pumps. The first one is the gear pump, then you have a vane pump and the last one is a piston pump. Learning about these pumps will help in determining the basics of its designs.

The first one is a gear pump

It is a basic example that you will see on a mobile machine. You can see it in PTO or can use it on a log splitter. Log splitter will have a two-stage pump. The design is quite basic. Some might have steel housing and some smaller ones will have aluminium hosting and steel ends. The prime mover can be either motor, electric or gas engine to rotate the primary inlet shaft.

  • Within the pump, spur gears will mesh together whenever you are rotating inlet shaft. It will rotate the secondary gear sets.
  • Fluid gets sucked in by increasing displacement inside the cavity. Then, the fluid gets trapped between housing walls and spur gears.
  • Later, the fluid gets carried outside and hits the pressure side of the pump, where it might get fed into the system.
  • These gears are capable of higher speed. It is important as most of the major movers in the mobile industry are gas engines with little horsepower.

Next is the vane pump

Here, the suction ports of such pumps are larger. It is designed to reduce restriction and then reduce vacuum and gravitation. With this pump design, the pressure ports and suctions can be properly rotated. It helps you to have ideal pressure and suction configurations.·

  • The pump is always trying to put one particular pressure. If you resist it more, the flow will get reduce. There are some advantages to such a controlling flow. But for that, you have to maintain the flow control or through the valve.
  • This mechanism is quite efficient too. Other than providing you with full flow and pressure, it will provide the exact pressure you need and cut the flow to compensate for higher pressure.

Piston pumps are the last ones

These piston type hydraulic pumps are familiar to closed-loop type. There are three types of piston pumps available. Those are bent axis piston pump, axial one, and radial piston pump. These three are nice designs and common, each to this pump family.

  • The bias piston always works hard to have full displacement and the displacement will decrease with control piston now. Similar to this mechanism is the vane pump.

Go through all the versions of hydraulic pumps are important before making the final call. The hydraulic pump designs will vary based on the selection made, but these items are known to last for a long time. Checking out with the experts will help you in big ways possible.


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