Why Choose a Hydraulic Motor over an Electric Motor?

In summary: Electrical motors can be attached directly to the prime mover without the need for an actuator. Hydraulic motors are also quieter due to the fact that they do not make the typical 'crunch' noise electric motors do. They are also easier to start as the prime mover does not require any type of electric current.
  • #1
Ronnin
168
1
I'm a store manager for an industial distributor here in Houston. I have several lines for electric motors but don't get into any hydraulics. I had a customer ask me to quote him on a Vickers hydraulic motor and it made me curious as to why someone would choose to go with a hydraulic motor vs an electric. Are there any cut and dry reasons why one would spec one versus the other? Just curious.
 
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  • #2
You get a lot of power and torque in a small package.
Also handy if you have compressed air/hydraulic power available anyway - like in an excavator or you want to avoid any sparks or electric shock risk with water - like in tunnelling
 
  • #3
You get a lot of power and torque in a small package.

Indeed. A hydraulic motor about the size of your fist can easily put out around 7kw of power. You can commonly find hydraulic motors on cooling fans of equipment that already have hydraulic systems. For example a front end loader or excavator. Also, the Jeep Commander and Jeep Grand Cherokee 05-09 (I think) models have hydraulic motors powering their cooling fans.
 
  • #4
Good info. I appreciate the responses. I can't stand when I'm asked about product I don't know enough about.
 
  • #5
I don't know whether this is universal or not, but I've found hydraulic motors to be much quieter than electric ones. That is assuming, of course, that the pump is in a remote location.
 
  • #6
I built tracks for crashtest before. Both hydraulic and electric motors were possible to pull the car (...or the truck) to be crashed.

Hydraulic motors are indeed smaller at identical power and especially torque. Their speed and position can be regulated very well, though not as precisely as for electric motors. Price also was a bit lower because of the inverter.

A very distinct advantage for us was the ability to store energy in 300b nitrogen and release 1MW power or more to the hydraulic engine. Electric motors were only possible where the mains allowed such powers. Batteries can't compete.

As for actuators - that is, cylinder as compared to electric motor+spindle, the advantage was even clearer. The spindle could give a high force and even power in an acceptable volume, but by no way could it react as quickly as a valve +hydraulic cylinder does. We regulated 3MN (the weight of 2 locomotives) within 10ms with a few % precision: don't even dream of it with electric motors, alas.

The dark side of hydraulics is the fluid, so this is quite hopeless. It does leak often. It does require maintenance. It does fail. And it's dirty.
 
  • #7
Hello Everyone, please bare with me, I'm new at this. Ron, the question of Hydraulic vs. electrical in the motor realm is a no brainer if you could compare the two. As stated by the posts, hydraulic motors the way to go once the prime mover has been decided on. Your customer was probably buying that motor to be attached to an electric motor to move fluid for whatever reason or attached to an internal combustion engine to activate accessories i.e. power steering, front end loader bucket or engine starting unit. That Hydraulic will need a prime mover to actuate.
 

What is the difference between an electric motor and a hydraulic motor?

An electric motor uses electricity to convert electrical energy into mechanical energy, while a hydraulic motor uses pressurized fluid to create rotational motion. In other words, an electric motor produces movement through the use of electricity, while a hydraulic motor uses fluid pressure.

Which type of motor is more efficient?

Electric motors are generally considered to be more efficient than hydraulic motors. This is because they have a higher power-to-weight ratio, meaning they can deliver more power for their size. Additionally, electric motors do not have any fluid losses, unlike hydraulic motors which can experience leakage and friction losses.

What are the advantages of using an electric motor?

There are several advantages to using an electric motor. They are generally more compact and lighter than hydraulic motors, making them easier to install and use in a variety of applications. They also have a higher operating speed and can provide more precise control over the speed and torque of the motor.

In what situations would a hydraulic motor be the better choice?

Hydraulic motors are often preferred in applications where high torque and low speeds are needed, such as in heavy machinery or equipment. They also have a higher power density, meaning they can deliver more power in a smaller size. Hydraulic motors are also well-suited for use in harsh environments, as they are less affected by temperature and contamination.

Can an electric motor be converted into a hydraulic motor?

No, an electric motor cannot be directly converted into a hydraulic motor. They operate on different principles and require different components. However, there are hybrid systems that combine both electric and hydraulic components to provide the benefits of both types of motors.

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