Safety of hydraulic pumps and motors

Hydraulic systems are used in a variety of industrial applications and they come in many different shapes and sizes. They are used so widely because of their power, control accuracy and relative simplicity when compared to electric or other of mechanical drive systems.

Because hydraulic systems utilise high-pressure hydraulic fluid alongside pumps and motors, if something does go wrong, negative consequences can be severe. As a result, hydraulic systems must have a number of safety measures inbuilt in order to function safely. Anyone using a high-power hydraulic system should also be aware of safe operation procedures and what to do in case of an emergency.

Below we’ll run through some of the safety features commonly found in hydraulic systems, in particular hydraulic pumps and motors.

Hydraulic systems as a whole

Hydraulic systems are used in a number of applications, from heavy duty industrial machinery, such as excavators, to more complex systems such as those found in aircraft. All hydraulic systems are comprised of the same main components. Hydraulic pumps and motors are the components responsible for transferring power throughout the system. The hydraulic fluid itself is the medium through which power is transferred and pipes and chambers are used to channel the fluid to functional areas.

Generally, hydraulic systems tend to fail as a result of a few key components. Seals around pistons, valves and plumbing connections are more prone to deterioration than solid components within the system. If a seal breaks, hydraulic fluid can leak out, causing a pressure drop, thereby reducing the effectiveness of the system to the extent where is becomes inoperable. In some cases, where a microscopic hole or crack appears in a hose, a stream of hydraulic fluid can escape at very high pressure. As small streams of hydraulic fluid can be very hard too see, they can cause serious injury if they come into contact with skin. Not only is hydraulic fluid contained within the system at very high pressures, it can also get very hot. This adds a double risk of cuts or burns from high pressure, heated hydraulic fluid, as well as broken hydraulic lines which can flail violently if broken.

Safety of hydraulic pumps

Hydraulic pumps are the components which take kinetic energy and turn it into hydraulic pressure within a system. As such, they function at the input side of the system, taking energy from an outside source, usually an electric or internal combustion engine, and transfer it as pressure within the hydraulic system.

There are a number of different types of hydraulic pump, the most common utilise interlocking gears to pump hydraulic fluid through the system. Alongside their simplicity, one of the main advantages of gear pumps is their tendency to wear down gradually over time. This means that gear pumps generally don’t fail in the same catastrophic manner as other pump types.

For applications which require very high-pressure hydraulic loads, other pumps, such as rotary vane pumps, are used. Although they are able to withstand higher pressures, failure can be more explosive when it does occur.

As hydraulic pumps function at the input side of the hydraulic system, they are less susceptible to the effects of the load at the output side of the system. This could be the weight of the load being held on the forks of a forklift truck or the resistance of the ground being worked by an excavator.

Safety of hydraulic motors

Hydraulic motors function in much the same way as hydraulic pumps, except they sit on the output side of the hydraulic system. Instead of transferring kinetic energy from an electric or mechanical input to the hydraulic fluid, hydraulic motors take the pressure from the hydraulic fluid and transfer it back into rotational/kinetic energy. This can be achieved using the same mechanisms found in hydraulic pumps, for example gears or rotary vanes.

Unlike hydraulic pumps, most hydraulic motors cannot be back-driven. Hydraulic motors are also susceptible to movement after system pressure and power has been turned off. This is because they usually have a drain reservoir attached to them. If system power is lost, either through a fault or power being turned off, movement of key load bearing components can be a serious safety hazard.

To combat this additional risk, key hydraulic motors have integrated braking systems to stop unwanted movement. Hydraulic pumps are less susceptible to movement because they are attached directly to the primary drive components, i.e. electric motors.

Working with hydraulic systems requires a high level of safety consciousness at all times. Hydraulic systems have many different safety features incorporated into their design. While these features protect against failures during operation, workers should still follow safety procedures at all times when working with hydraulic systems to protect themselves from unexpected failures and accidents.

If you would like to learn more about hydraulic systems, their various operational components, or the range of hydraulic systems we offer, please get in touch today.