04 Feb

Different Types of Hydraulic Pumps

If you’ve been following our blog or even if you just happen to know quite a bit about hydraulics, you’ll already be aware that hydraulics are one of the most efficient methods of transferring energy. In today’s post we’re going to be exploring the various hydraulic pumps that enable this amazing form of energy engineering to happen.

Hydraulic energy is very powerful and efficient. It’s something that experienced engineers still marvel at for its ability to literally move mountains. In today’s world, a lot is asked of machinery and it’s the hydraulic pump that enables awe inspiring hydraulic energy to be delivered where it’s needed.


What is a hydraulic pump?

The purpose of the hydraulic pump is to convert from mechanical power to hydraulic energy. This energy can then be used to operate a variety of different devices. The pump works by generating flow with enough power to overcome pressure induced by the load.

First it will create a vacuum at the pump inlet. This will force liquid into the pump’s inlet line from the reservoir. The mechanical action of the pump will then move the liquid or fluid to the pump outlet and then force it into the hydraulic system.

Pumps move or create flow of liquid. They do not generate pressure, although they do facilitate the creation of the pressure by producing the required flow.


Types of Hydraulic Pumps

There are a variety of different hydraulic pumps on the market. Let’s take a look at the different types:

Hand pumps

Hand pumps are manually operated and will usually work in a suction type way.

Gear Pumps

These are the most commonplace type of pumps, probably because they are recognised as being low cost, simple and durable by engineers and system designers.  They are pretty easy to maintain and are considered to be the most economical when it comes to hydraulics. They are also considered to be suitable for pressures below the 3000 psi mark because they work with a constant displacement they may be less efficient in some situations. This makes them best suited to simple hydraulic systems.

Vane Pumps

Another low cost option that is also of simple design and therefore more reliable. This is particularly true of the gerotor form. They are suitable for low-pressure but higher flow output. They offer higher efficiencies than can be found in gear pumps and are most often used for mid-range pressures up to 180 bars.

Axial Piston Pumps

These type of pumps are a little more complicated than those we’ve looked at so far. Most of them come with a variable displacement mechanism. This will make it possible for you to vary the flow for automatic control of pressure. Some design types include swash plate (also known as valve plate) and check ball. The latter is sometimes known as a wobble plate pump. These types of pumps can take up to 350 bars. Some types are more sensitive to oil contamination, so do your homework first.

Gerotor Pumps

Similar to the gear pump, the gerotor pump is in effect a version of the gear pump. A rotor gear and idler gear work together to create a suction and act like a seal for fluid. Once the liquid is inside, it will pass through the gears and then be pushed out through the pump’s outlet. These types of pumps are known to be good for medium pressure and have a good efficiency and level of sound considering this.

We’ve explored just a handful of pump types that can be used in a hydraulic system. Watch this space for more posts.