In modern industry, hydraulic motors and electric motors are two common driving devices, each having their own unique advantages and applications. This article will introduce the comprehensive comparisons of the two motors, and tell you how to choose the proper one for your projection.
What are Hydraulic Motors
The hydraulic motor is an actuator component that can convert the hydraulic energy into rotational force. Hydraulic motors typically drive the mechanical equipment working with the assistance of hydraulic pumps. They are similar to hydraulic pumps, but have the opposite function.
According to the differences of structure, hydraulic motors include many types such as gear motors, vane motors and piston motors. The gear motor has benefit on cost, and it has perfect durability and a simple structure to maintain. It is easy for vane motors to keep low noise, and it has a stable output process. If you need a hydraulic motor with high efficiency, then the piston motor is a good choice.
What are Electric Motors
Electric motors can convert electrical energy into mechanical energy, it is a type of driving device. The working principle of electric motors is connected with electric current. They can produce a magnetic field through current, making the rotor whirling, and driving the mechanical components to move.
Electric motors mainly include AC motors, DC motors and servo motors. Among them, the structure of AC motors is simple to maintain and it is reliable. The DC motor is more flexible, and its rotation speed can be adjusted according to specific requirements. For high precision control, servo motors have a significant advantage, and they can respond quickly.
Comparison of Hydraulic and Electric Motors Performance
Hydraulic motors and electric motors not only have differences on structure and principle, but also differ about performance. The following may help you deeply understand the comparison between them.
Power Density
Power density is the power that single volume or weight outputting. Due to the liquids are nearly incompressible, the hydraulic motor has a significant advantage on power density. The hydraulic system can produce excessive torque and output power with small volume.
The power density of electric motors is usually lower than hydraulic motors. To reach the same output power, the electric motor typically requires bigger volume and weight, which is a challenge for your space. However, a high performance servo motor may overcome this shortness.
Control Precision
Control precision refers to the performance of motors in controlling speed, position and torque. It is an important indicator to test the motor performances. Hydraulic motors have a lower precision than electric motors. This is because hydraulic fluids may appear fluctuations and leakages when flowing, and the response will become slow. But its control precision can be improved by installing devices such as proportional valves, servo valves.
The electric motors have outstanding speed and position control capabilities. Servo motors can especially achieve high precise motion control, and are ideal to be used in automated production lines, robotics, or other industries that require strict precision. If you want to use motors in high precision situations, electric motors have a big advantage.
Efficiency
The hydraulic system may exhibit energy losses due to leakage, friction or fluid compression when conveying energy. So the overall efficiency of hydraulic motors is lower than electric motors. Moreover, the hydraulic system needs continuous operation to keep proper pressure, it will consume energy even in the no-load condition. This may increase energy consumption and make the device overheat.
While the electric motor commonly has high efficiency, particularly some high performance motors, whose efficiency can reach around 90%. When it experiences intermittent operation or low load condition, the electric motor can start or stop at any time according to your requirements to save energy and costs.
Durability and Maintenance
Durability is also a crucial performance that can reflect the abilities of devices in resisting wear, shock and harsh environment. While maintenance is closely related with late costs and downtime of motors.
Hydraulic motors possess good durability and strength, especially suitable for high impact and harsh conditions. But it is complex to maintain the hydraulic system, which needs to clean or replace hydraulic fluids and check leakage periodically. Once the fluid leaks, it may cause device downtime and environment solution, leading to a high maintenance cost for your project.
The structure of electric motors is relatively simple, routine maintenance is mainly concentrated in bearing lubrication and electrical check. It has low failure rates and short downtime, and is easy to diagnose and repair. So, it is convenient to maintain the electric stable, suitable for uninterrupted production.
Cost
The hydraulic motor is economical, but due to the consumption of fluids, leakages and frequent maintenance, it has a high operating cost for the long term. Additionally, when the hydraulic system is broken, hydraulic motors will be shut down for a long time, significantly impacting normal production.
While the electric motor has higher investments in the initial stage, especially to the servo motor. However, the overall cost of the electric motor is typically lower. Because its service life and efficiency is excessively outstanding, and is easy to maintain. It is a best choice if you pursue long-term investment returns.
Applications of Hydraulic Motors
Construction
The hydraulic motor is widely used in construction industries and large machinery, such as excavators, bulldozers and cranes. These equipment often operate for high shock or load works in harsh outdoor environments. Hydraulic motors provide strong torque in limited space, ensuring the stability and safety of your devices.
Agricultural
Agricultural machines need to operate for continuous time, and the environment is commonly muddy and damp. The hydraulic motor will provide strong driving power for the machines and achieve multiple functional control through the simple hydraulic circuits. Common hydraulic motors driving machines include harvesters, tractors, and sprayers. The hydraulic motor is easy to maintain and replace damaged components quickly, which can decrease the downtime losses during peak farming reasons.
Mining
For the mining industry, hydraulic motors have a significant advantage for the equipment such as mining machines or drilling equipment. The environment of mining mountain and oil fields is very harsh, which means equipment needs to work in the high temperature, high pressure, even high corrosion conditions. While the hydraulic motor can resist these pressures, and stably output power in extreme conditions. If your project is meeting these issues, hydraulic motors are an ideal choice.
Applications of Electric Motors
Automated Producing
The electric motor is commonly used in automotive production lines such as convey devices, upload lines, machinery packages, electrical manufacture, and etc. These producing lines have a strict demand on control functions, and the motors need to achieve precise and fast moving. Electric motors, especially the servo motor, possess high response speed and high precision control, improving production efficiency and consistency.
Smart Manufacturing
The smart manufacturing industry, such as industrial robots and automated sorting systems, requires highly precise controls, and the electric motor can meet these demands. Servo motors control moving precisely, and it can plan complex trajectory. If your projects have a high precision requirement, consider using the electric motor.
Food and Pharmaceuticals
Food and medicine is strict for cleanliness of the devices, any fluids leakage or pollution may cause a serious consequence. While the electric motor is driven by electricity instead of fluids, it avoids pollution risk. And the process of electric motors is silent and clean, and can reach the industry standards.
How to Choose a Suitable Motor
When you selecting the motors, you can consider some factors such as the followings:
Power and precision: Although the precision of hydraulic motors is insufficient, they can output high power and torque continuously. In contrast, electric motors offer high precision but lower power.
Energy efficiency: If your project demands sustainable and green development, electric motors are more suitable. They can minimize the energy consumption with the help of energy-saving control systems. While hydraulic motors may consume more efficiency than electric motors due to the heat loss issues.
Budget and total cost: Hydraulic motors have lower initial investment than electric motors, but the long-term operating costs are higher. Electric motors usually have a long service life and are easy to maintain. You can choose a proper one according to your budget and total cost.
Conclusion
Hydraulic and electric motors are different in many ways, both have their own advantages and shortcomings. Choosing the most suitable one according to your requirement to achieve high efficiency. If you have any other questions, feel free to contact us for a professional solution.
FAQ
If hydraulic motors and electric motors used together?
In some complex industrial situations, the single type of motors is difficult to meet all requirements, so hydraulic and electric motors can be used together. The combinatorial system can strengthen the advantages of two motors, producing a complexion performance that includes precise control of electric motors and powerful output of hydraulic motors. Examples include large injection molding machines and defense equipment testing platforms.
