In industrial equipment, hydraulic and electric actuators are the most common types of actuators. The choice of actuator in a real-world project often affects how stable and easy to maintain the equipment is. This article will compare the two types of actuators, think about the load, environment, and how risky it is to use them. This will help you make a good decision when designing or upgrading equipment.
What Really Matters When Selecting an Actuator？
When choosing an actuator, there are a few things to think about:
Force / Torque
How much thrust or torque does the equipment really need? This is the first thing you need to think about when choosing.
Shock Load
Will there be shocks or momentary overloads while the machine is running? This often determines reliability.
Duty Cycle
Does the actuator only operate now and then, or does it need to run for a longer time?
Environment
Is the site hot, dusty, or damp, or does it need a clean environment?
Precision
Do you really need to be very precise, or is accuracy not that important?
Speed & Response
Does the actuator need to move really quickly? Does the system have to respond quickly?
Maintenance Risk
How easy is maintenance? If something goes wrong, will it be very inconvenient?
Total Cost of Ownership
As well as the purchase price, how much will the energy consumption, maintenance, and the whole lifecycle cost?
Failure Consequence
If the actuator stops working, what will happen to the equipment and production?
Hydraulic vs Electric Actuator: What Really Matters in Industrial Applications
I will compare how well these two types of actuators work in industrial equipment.
Force & Load Capacity
The force that a hydraulic actuator can produce depends on the pressure in the system and the size of the piston. Common industrial hydraulic systems typically operate at pressures between 160 and 250 bar, reaching up to 315 bar under heavy load conditions.
Hydraulic actuators can reliably provide forces ranging from tens of kilonewtons to hundreds of kilonewtons, and even megajoules in large equipment, within this pressure range. You can change how much force a hydraulic system can output by changing the pressure and flow rate.
This means that the system can keep working similarly even when the load is close to its rated value. So, it is best to use it for applications that require a lot of power for a long time.
The force that an electric actuator can produce comes from the motor torque (turning force) that is sent to the load end through a reduction mechanism and a lead screw or gears. In engineering, electric actuators are usually used within a range of a few kilonewtons to tens of kilonewtons.
If the thrust requirement is close to or over 100 kilonewtons, the actuator size, how complex the structure is, and the cost will increase a lot. At the same time, the system needs to be more stable.
So, electric actuators are better for use when the load is clear, the variation is small, and the long-term operating conditions are stable.
Shock Load & Overload
In hydraulic systems, when the load suddenly increases, the first thing that usually changes is the system pressure. The pressure increases with the load and is controlled and limited by valves, pipelines, and the system’s own characteristics.
So, problems in how it’s being used are more likely to show up as changes in pressure than as problems in the structure straight away. In real-world uses, valves and other parts can be used to set clear and predictable limits for overload situations. This makes it easier for the hydraulic system to stay in control, even when it is shocked.
When electric actuators are under pressure or overload, how they respond depends a lot on the control and protection strategies in place. If the load is higher than expected, the system usually identifies the problem by checking the motor current, torque, or position.
It then puts protective measures in place, such as limiting the current, setting alarms, or shutting down. This approach works well when the conditions are clear, and you can predict the load variations.
But in situations where there are a lot of impacts or where it’s hard to define what’s different in advance, the system’s safety depends more on whether the original design was strong enough and whether the protection plan thought about all possible situations.
Duty Cycle & Continuous Operation
For hydraulic actuators, the main heat source is not the actuator body itself. The heat created when it is being used is mostly found in parts like the hydraulic fluid, pump and valves. This heat can be removed through the oil tank, piping or a cooler.
Therefore, if hydraulic systems are designed well enough to keep cool, they can usually be used continuously and stably when there is a lot of demand, and they are used for a long time, without the risk of overheating.
Things are different for electric actuators. The motor and driver are both the power source and the main heat source, and the heat they generate is concentrated in a relatively enclosed structure. If the actuator is used for a long time under a lot of pressure and doesn’t get cooled down quickly enough, it will get too hot.
In engineering, electric actuators are usually used for 10% to 30% of the time. If this happens, the system will often reduce its power output or switch off to stop itself from getting damaged.
Precision & Position Control
The best thing about electric actuators is that they are very precise and allow you to control the position. Through encoders, servo motors and control systems, electric actuators can achieve very high repeatable positioning accuracy, commonly reaching ±0.01 mm or even higher in engineering applications.
This accuracy and consistency are very useful in equipment that needs to be positioned or controlled perfectly, and they are also easier to adjust and improve using software.
Hydraulic actuators are not usually known for being very precise. Traditional open-loop hydraulic systems are not very accurate, but stable and repeatable position control can be achieved through displacement sensors and closed-loop control.
In real-world engineering situations, hydraulic systems usually have a positioning accuracy of about ±0.1 mm. This is usually enough for a lot of heavy-duty industrial equipment. Hydraulic systems are better at staying stable when there are different loads.
Installation & System Complexity
For hydraulic actuators, installation usually means setting up a complete hydraulic system. This includes a reservoir, pump, valve manifold, and piping. You need to think more about space planning and pipe routing at the start, but once the system is built, most of it works on mechanical and hydraulic systems, with less reliance on control software and communication.
In multi-actuator applications, hydraulic systems can also achieve a certain degree of system balance through pressure and flow distribution, making the overall structure easier to understand and maintain.
Electric actuators, on the other hand, are usually easier to install. You don’t need to add any extra piping or power units. You just need to connect them to a power supply and control signals. This is one reason why they are so popular in automated equipment.
But electric actuators need more control systems, communication, power supply and electromagnetic compatibility. If you have more actuators, or if you need to control multiple axes at the same time, it can be harder to understand the control logic, debug the system, and solve any problems that might come up.
This is because the system is more complex, and it can be more difficult to figure out what’s going on.
Installation & System Complexity
The way hydraulic actuators are maintained is usually quite simple. Common problems include seal ageing, leaks, oil contamination, or performance degradation, which tend to develop gradually rather than suddenly.
A basic inspection and maintenance plan can spot and fix a lot of problems early on. In engineering, we can see what problems hydraulic systems can cause, and maintenance staff can easily work out what is wrong by looking at the symptoms. So, although the maintenance may be more often, it is easier to predict.
Electric actuators are less likely to cause problems when used every day. They don’t require hydraulic fluid to be handled and are less likely to have visible issues. But when something does fail, the situation is often more complicated.
Problems can come from the motor, driver, sensors, or control system. Sometimes, the problem is not easy to see, so you need special tools or people who know how to fix it. In some cases, electric actuators fail suddenly and are only discovered after downtime.
This could cause problems, so it’s important to think about this in advance, especially for equipment that needs to be kept running or for which there is not much time for maintenance.
Energy Efficiency
Electric actuators are usually more energy efficient when they are used less or only sometimes. The actuator uses electricity only when it needs to move, and almost no energy when stopped.
This makes it very efficient in applications where it is switched on and off a lot, and for short periods of time. This means that electric actuators often use much less energy when equipment has lighter loads and is operating in clear cycles.
The energy efficiency of hydraulic actuators depends more on how they are designed and how they are used. When they are used for a long time or under a lot of pressure, hydraulic systems can usually be relied on to work well and will not become less efficient.
Although hydraulic systems can still lose energy when they are not being used or in standby mode, they are often more controllable and better suited to how they are actually used in applications where they are used continuously under high loads.
Total Cost of Ownership
The first setup of hydraulic actuators is usually more complicated. You will need a hydraulic power unit, piping and related accessories, which can seem like a lot of money to spend at first.
But in the long run, the costs and risks of hydraulic systems are relatively easy to predict. Maintenance mostly focuses on fluids, seals and standard parts, and the maintenance procedures are well-known.
This makes it easier to plan for the cost of maintenance. This is often better for equipment that has a high workload, or which needs to be used all the time, because it stops the cost from going up when it is not being used.
Electric actuators, on the other hand, are usually simpler to buy and install, with a simpler system and clearer initial costs. For applications that don’t have much weight and have regular operating cycles, the energy costs and maintenance costs over time are often lower.
But if it breaks, the problem might be in the motor, driver, or control system. This means you’ll need more skilled workers and time to figure out what’s wrong and fix it. In situations where downtime is very important, this risk of downtime can greatly increase the total cost of owning the system.
The table below shows the features of electric and hydraulic actuators in different ways.
| Comparison Dimensions | Hydraulic Actuator | Electric Actuator |
| Force & Load Capacity | It can bear a lot of weight, making it good for heavy-duty work. | It is better for working conditions where the workload is low to medium. |
| Shock Load & Overload | It can handle impact and sudden changes better. | It is more sensitive to shocks and overloads, so it needs extra protection. |
| Duty Cycle & Continuous Operation | It is more stable under high loads and when it is used for a longer time. | If you keep the system under a high load for a long time, it will be very stressed. |
| Precision & Position Control | The accuracy can be controlled, but that’s not its main benefit. | The movement is more precise and consistent. |
| Installation & System Complexity | The system is complicated and needs a hydraulic system to work. | It has a compact structure, which makes it easy to install and integrate. |
| Maintenance & Failure Risk | It is important to regularly check the fluids and seals, and maintaining these parts is a long-term task. | It doesn’t need much maintenance, but if there is a problem, you’ll have to check the electronic control systems. |
| Energy Efficiency | It works well even when it is under heavy load and is used for a long time. | It uses less energy when there is a light load, and it is running on and off. |
| Total Cost of Ownership | The initial costs are not too high, but you have to think about maintenance and energy consumption. | Initial costs are higher, but over time, the total cost of ownership is lower if the machine is used in the right way. |
When a Hydraulic Actuator Is the Better Choice？
These are the best uses for hydraulic actuators:
Equipment that needs a lot of power, like heavy machinery, moulding, and pressing equipment.
It can be used in situations where there are shocks or occasional overloads.
These are tough conditions for machines to work in. For example, they can be very hot or cold, dusty or wet.
It is used in situations where the actuator needs to work for a long time with big changes in load.
Equipment that would cause big losses if it stopped working.
When an Electric Actuator Makes More Sense？
Electric actuators are usually better for the following uses and situations:
Equipment with light loads and movements that are not too fast or too slow.
Equipment needs to be very precise and consistent.
Applications that need to be clean and quiet, like indoor equipment or automated production lines
The equipment is easy to install and can be used with other systems, so you don’t need extra pipes or power units.
Equipment that only needs to be switched on for a short time.
Common Actuator Selection Mistakes in Industrial Projects
In industrial projects, problems with actuators are often not due to poor equipment quality. Instead, they are caused by problems that happened when the equipment was chosen. Here are some common mistakes:
Focusing too much on accuracy and not enough on safety margins can make the equipment unstable when it’s under a lot of pressure.
It is easy to underestimate how shocks and occasional overloads can lead to safety accidents during operation.
Only think about the rated parameters and don’t worry about the heat that is produced when it is used for a long time. This heat affects how long the actuator will last.
Trying to replace hydraulic systems with electric ones, but not changing the system design and protection measures at the same time.
Making decisions based only on how much something costs, without thinking about the risks of it being out of action and how much it will cost to run it.
How to Choose the Right Actuator: A Practical Checklist
To choose the right actuator, follow these steps:
First, you need to know exactly which conditions are critical and cannot fail. These include things like load, safety, or downtime risks.
Next, work out how the equipment is going to be used. Does it work all the time or just when it’s needed?
Check how well the site is used and how it is maintained, including things like the environment and how easy it is to maintain in the future.
Think about whether you really need to be so precise, as this can make things more complicated than they need to be.
Think about what would happen if something went wrong, what the problems with the equipment might be, and how much it would cost to fix them.
Finally, match the specific model and parameters, rather than being misled by the parameter specifications.
It’s important to note that some risks to the actuator only appear after months of real operation, not on datasheets.
FAQ
What are the differences between hydraulic and electric actuators in the event of a power outage or emergency shutdown?
When the power is cut off, hydraulic actuators are more likely to stop and hold their position or release slowly, while electric actuators rely more on brakes and control systems.
If the equipment is likely to be upgraded or expanded in the future, how will the choice of actuators affect later modifications?
Once you’ve chosen an actuator, you can’t upgrade it in the future. The better the first choice, the less you’ll need to change later.
Does the choice of actuators affect whether the whole system can pass customer or industry certifications?
Yes, the choice of actuators has a big effect on the safety design and failure modes, and these are often key parts of the certification process.
For existing equipment, how long does it usually take before problems with selecting the actuator become clear?
Most problems with choosing equipment don’t become obvious straight away. These problems appear after the equipment has been used for several months.
What are the differences between hydraulic and electric solutions in multi-actuator systems?
Hydraulic systems rely more on the balance of the system itself, while electric systems depend more on the control system. The more actuators there are, the harder it is to coordinate them.
Does the choice of actuators affect how long it takes to deliver the equipment and how hard it is to provide technical support afterwards?
If the selection process is clear and well-defined, the delivery will be faster and easier to support. However, more problems will likely occur.
Final Thoughts
If you are comparing hydraulic and electric actuators, it shows that your project is at a stage where it is very important to manage risk. Choosing the right actuator is important. It’s not just about picking one part. It’s about making sure your equipment works well for a long time. Target Hydraulics has been making hydraulic power units for over 10 years. We can assess your system by looking at how it actually functions in real-world conditions. This means we can give you more reliable advice about how to design your actuators and systems. This will help to reduce the time when they are not working and the risks of needing maintenance in the future. If you want to think about all the options in more detail, just contact us.
