Hydraulic Gear Pumps
- External, Internal and Helical -
Reliability, robustness and versatility for industrial and mobile applications.
Hydraulic gear pumps are the most widely used pump type in industrial hydraulics. Characterised by a simple and robust design, they offer an effective and cost-effective solution for most applications requiring fixed displacement. They guarantee excellent reliability and a long service life, even in harsh environments.
Fluid System, as an authorised distributor of leading brands such as Marzocchi Pompe and Bosch Rexroth, offers the full range of gear pumps for industrial hydraulic applications covering every requirement in terms of pressure, flow rate and noise level: from standard external gear pumps to internal gear pumps and helical technology for maximum low-noise performance.
Gear Pumps:
the main types
The three main gear technologies offer distinctive advantages in terms of efficiency, pressure and acoustic impact.
EXTERNAL GEAR PUMPS
Characterised by two identical external gears (one driving and one driven). They are the simplest and most versatile type, offering an excellent compromise between cost and performance.
INTERNAL GEAR PUMPS
A variant of external gear pumps that uses helical teeth to significantly reduce flow pulsation and noise. They are the ideal option when noise is a critical factor.
HELICAL PUMPS (ELIKA)
A variant of external gear pumps that uses helical teeth to significantly reduce flow pulsation and noise. They are the ideal option when noise is a critical factor.
Comparison of Gear Pumps
| Characteristic | External Gear Pumps | Internal Gear Pumps | Helical Pumps (Elika) |
|---|---|---|---|
| Operating pressure | Up to 290 bar (peak) | Up to 315 bar (peak) | Up to 310 bar |
| Flow control | Fixed displacement | Fixed displacement | Fixed displacement |
| Noise level | Standard | Low (thanks to internal compensation) | Extremely low (up to -15 dBA) |
| Volumetric efficiency | Good | Very good (thanks to clearance compensation) | High even at low speeds (axial compensation) |
| Application flexibility | Wide: auxiliary circuits - mobile machinery | Industrial systems requiring low noise | Noise-sensitive environments (e.g. lifting systems - low-noise machinery) |
| Distinctive feature | Simple design - wide size range | High pressure - low noise | Exceptionally low noise - minimal flow pulsation |
| Main brands | Marzocchi Pompe | Bosch Rexroth | Marzocchi Pompe |
When to choose which
Choose Gear Pumps if...
- you need simplicity and robustness in fixed-displacement systems.
- the application does not require variable flow control.
- cost is a key consideration and the application is not as dynamic as one based on piston pumps.
Choose External Gear pumps if...
- you are looking for the most versatile, compact and cost-effective solution (Groups 1-4).
- the application falls within the medium-pressure range (up to 200/250 bar continuous).
Choose Internal Gear pumps if...
- you need high pressures (up to 315 bar) with significantly reduced noise.
- the application requires higher volumetric efficiency than external gear pumps can offer.
Choose Helical pumps (Elika) if...
- quiet operation is a key requirement (e.g. indoor machinery, lifts).
- the application requires high pressure and extremely low flow pulsation.
Explore the available solutions
Fluid System offers gear pumps from the best international brands, selected to ensure high performance, efficiency and long service life. Select a pump type to explore features, available series and application advantages.
Request technical consultancy
Every hydraulic application has specific requirements. Contact us for support in selecting the pump best suited to your requirements in terms of flow rate, pressure, duty cycle and control logic.
Hydraulic Gear Pumps - Frequently Asked Questions
External gear pumps are the most common and cost-effective solution. Thanks to their design, internal gear pumps offer better high-pressure performance and much lower noise levels, making them more suitable for precision industrial applications.
A helical pump (Elika) is chosen when noise reduction is a critical factor. Thanks to its special tooth profile, it reduces noise by up to 15 dBA and is ideal for noise-sensitive systems such as those used in the marine or lifting sectors.
Yes. Both Marzocchi and Bosch Rexroth offer gear pumps that can be coupled, using dedicated kits, in double or triple configurations, combining pumps from different groups or even coupling them with pumps based on other technologies (e.g. piston pumps).
In general, gear pumps are fixed-displacement pumps and do not offer the energy savings of variable-displacement systems, such as piston or vane pumps. However, they can be integrated into energy-saving systems when used with variable-speed motors or servo pumps.
They are widely used in almost every sector, from standard machine tools to mobile vehicles (on-board power units), right through to auxiliary systems such as cooling and filtration, thanks to their robustness and simplicity.
