What Information Is Needed to Order the Right Orbital Hydraulic Motor?
Feb 22, 2026| As a professional manufacturer of orbital hydraulic motors, we often receive inquiries that start with a simple question:
"We need a motor. What information do you need from us?"
Compared with many standard mechanical parts, an orbital hydraulic motor is a relatively complex component in a hydraulic system. If some key parameters are missing, it is very easy to select an incorrect model, which may lead to poor performance, installation problems, or even system failure.
To help you communicate more efficiently with the factory and select the correct motor from the beginning, we would like to briefly introduce the main parameters that should be confirmed when ordering an orbital hydraulic motor.
1. Displacement – the most important parameter
Displacement is the first and most critical parameter when selecting an orbital hydraulic motor.
In simple terms, displacement directly affects:
the output torque,
the operating speed,
and how the motor matches your hydraulic system.
When discussing displacement with the manufacturer, you should be clear about the following system requirements:
What output torque does your application need?
What is the available working pressure of your hydraulic system?
What speed range do you require at the motor shaft?
These three points are closely related to displacement.
Only after understanding your pressure and speed requirements can the factory help you select a suitable displacement that can deliver the required torque in real working conditions.
For most applications, displacement is the starting point of the entire selection process.
2. Mounting and connection type
Orbital hydraulic motors are available in many different mounting and connection forms.
This includes, for example:
different output shaft types,
and different flange standards.
Even if two motors have the same displacement and performance, their mounting interface may be completely different.
Therefore, before ordering, you should clearly confirm:
the required output shaft type and size,
the flange type,
and how the motor will be installed on your machine.
3. Port type and size (inlet and outlet ports)
The inlet and outlet ports of a hydraulic motor also have several possible configurations.
Different hydraulic systems may use different:
port thread standards,
port sizes,
and port connection forms.
When placing an order, you should confirm with the factory:
the required port size,
the thread type,
and the connection standard used in your system.
This helps avoid mismatches with your existing hoses and fittings, and reduces unnecessary rework during installation.
4. Drain port requirement
Another important point is whether a drain port is required.
Some applications, especially those with higher back pressure or specific sealing requirements, need a case drain connection. In such cases, you should clearly specify:
whether a drain port is needed,
and what the drain port size and thread should be.
This detail is sometimes overlooked, but it can have a significant impact on the service life and reliability of the motor in real operation.
5. Overall dimensions and installation space
One commonly ignored factor is the overall size of the motor and the available installation space in your machine.
Different:
mounting types,
output shafts,
and port positions
will change the external dimensions of the motor.
Before finalizing the order, it is very important to confirm that:
the motor fits into your installation space,
there is no interference with surrounding components,
and the port directions are suitable for hose routing.
Even if the motor meets all performance requirements, an unsuitable external layout can cause serious installation difficulties or force changes to the machine structure.
Final note
In practice, a correct motor selection is not based on one single parameter. It is the result of combining:
system performance requirements,
mechanical connection details,
hydraulic interface specifications,
and installation constraints.
If you can provide the factory with clear information on displacement requirements, mounting and shaft type, port specifications, drain port needs, and installation space, the selection process will become much faster and more accurate.
As a manufacturer of orbital hydraulic motors, we recommend discussing these key parameters with your supplier at an early stage. This helps avoid repeated revisions, reduces project risk, and ensures that the motor you receive truly matches your application.