Choose your hydraulic motor
How to choose your hydraulic motor ?
Considering the hydraulic components, there are different types of hydraulic motors. Of course, each hydraulic equipment has its own peculiarities in the arrangement of internal moving parts. However, no matter which model you choose, the role of a hydraulic motor is always to convert hydraulic energy into mechanical energy. To help you make the right choice for your application, let's focus on hydraulic motors.
What is the hydraulic motor
It is a device which consists in transforming hydraulic power into mechanical energy by means of hydraulic pumps. It is a fluid under high pressure that provides the hydraulic power. In other words, this energy is made by the rotary motion of the output shaft.
In order to stimulate the hydraulic system, the motor has two characteristics, namely the motor torque and the speed of rotation. If the resistive torque is too high, the hydraulic pressure will rise. Once the pressure reaches the setting of the pressure relief valve, the flow is transmitted to the tank. The advantage of the torque motor is that it develops high power with less space requirements.
The hydraulic motor is necessary to guarantee the rotary movements, where the environment has risks of explosion and is in a zone of temperatures not easily associated with the traditional solutions.
What are the different types of hydraulic motors
There are 4 types of hydraulic motors, including
- Vane motors,
- Radial piston engines
- And gear motors.
Each engine has its own characteristics and performance.
The vane motor
It is important to note that all hydraulic motors have their own operating principle that relies on their direction of rotation. The particularity of the hydraulic vane motor is mainly in the elements that compose it and that allow it to make a very powerful starting torque. In fact, the vane motor has integrated springs that provide it with the necessary power to start the rotation movements.
The gear motor
The radial piston engine
The hydraulic radial piston motor comes in 2 types: the radial piston motor and the axial piston motor. The former operates in odd numbers and turns on a cam. On the other hand, the second one rotates through the pressure of a ball joint. Be aware that these engines are slow, but with satisfactory efficiency.
What failures can these engines encounter ?
Hydraulic motors are the same as all hydraulic valves. Indeed, these hydraulic devices can also fail. These malfunctions can be
- Aeration, which is characterized by the presence of air bubbles in the hydraulic fluid.
- Contamination that occurs during the introduction of a foreign body into the fluid.
- Cavitation occurs when the fluid no longer occupies all the space inside the pump.
- The internal leakage of the hydraulic system is due to the difficulties of regulation of the pump.
How a hydraulic motor works
Hydraulic motors work in the same way. The difference is mainly in the pressure between the inlet and the bearing and in the dimensions. It also occurs in the internal moving parts that are mechanically connected to the coupling shaft. The pressure difference causes these internal moving parts to move and cause the motor shaft to move. Regardless of the difference, the hydraulic motor emits a rotational motion to a load. In other words, the hydraulic energy obtained from the pressurized fluid is converted into mechanical energy.
How to choose a hydraulic motor ?
Just like the spare parts, it is also necessary to choose the right hydraulic motor. Of course, you must choose the right one for your hydraulic pump. In any case, here are some points to consider
- Application type;
- The maximum and average power to be awarded;
- Output shaft speed and torque spectra;
- External loads;
- The possibilities of implementation, the weight as well as the expected life span
- The weight/power ratio
- Hydraulic maintenance.
Whether slow or fast, motors have a volumetric efficiency. For production systems that require a fairly high performance, you can opt for different motors such as axial piston or tilt axis motors. These have a power of up to 500 kW, a torque of 160 daN.m and a speed range of 50 to 300 rpm. These motors have a good performance and a better efficiency.
On the other hand, for production lines that do not require high speeds but rather good robustness, axial piston motors and double plates are recommended. These hydraulic systems have a power of up to 250 kW, a torque of 1,000 daN.m with a pressure of 250 bar. They provide a wide range of speeds with a higher efficiency.
For very low speeds, radial piston engines are recommended, especially in rotating barrel technology. This type of engine has a speed range from 5 to 500 rpm. Also, their power can go in the 350 kW with the torque 650 daN.m, as well as a pressure of 450 bars.
Finally, for applications on agricultural machines, public works or sweepers, it is recommended to choose the orbital hydraulic motor. This type requires a lower speed and is available in several types depending on the rotation speed and maximum torque capacity.