Gear Pumps - The Rugged Solution for Efficient Conveyance of Lubricants, Fuels, and Abrasive Fluids

The technical starting point is the housing rigidity and the choice of material; at HARTON, we prefer gray cast iron to die-cast aluminum for high-pressure applications. As system pressure increases, the elastic expansion of the housing leads to an increase in the radial clearance, which exponentially increases internal leakage (slip). The result is a significant drop in efficiency, which—once a critical threshold is reached—increases the thermal load on the oil to such an extent that the viscosity falls below the permissible minimum for the bearing bush.

The design is based on movable pressure plates that are pressed axially against the gear faces by the operating pressure. This compensates for thermal expansion and minimizes volumetric short-circuiting. One risk is the abrasion of these compensation areas by particles larger than 10 µm, which drastically reduces the MTBF; our quality assurance team therefore always validates the cleanliness class in accordance with ISO 4406.

The starting point is the suction capacity in relation to the kinematic viscosity, which is often over 1,000 mm²/s during cold starts. The high flow resistance in the suction line causes the static pressure at the tooth engagement point to drop below the vapor pressure, resulting in the formation of vapor bubbles. The implosive recompression on the pressure side tears material from the involute gearing; our technicians therefore always verify the minimum inlet pressure.

Unlike spur gears, helical gears maintain continuous tooth engagement across the entire tooth width, which reduces the pressure amplitude by up to 75%. This smooth operation is essential to prevent measurement results from being distorted by induced pressure vibrations; however, the resulting axial force must be absorbed by reinforced needle roller bearings.

Differences in the coefficients of thermal expansion between steel shafts and housings alter the functional clearance dimensions at operating temperatures above 150 °C. Our manufacturing specialists calculate these tolerances precisely to prevent seizing during startup. An incorrect material pairing can cause jamming during thermal shocks; a temperature difference of 50 K can reduce the radial clearance by as much as 30%.

The pump continuously circulates oil through filters and coolers, ensuring that all friction points are constantly supplied with conditioned lubricant. A pump failure results in the rolling bearings overheating; our technicians therefore often integrate a redundant gear pump that is immediately activated via servo motors in the event of a pressure drop to ensure system availability.

While conventional drives are often controlled via throttle control, servomotor control enables highly dynamic speed control right down to a complete stop. This significantly increases efficiency but requires monitoring of self-cooling during continuous operation at low speeds, as otherwise the hydrodynamic load-carrying capacity of the bearing bush will be insufficient.

After defined operating cycles, we validate the flank clearance of the involute gearing using precision measuring equipment. Excessive backlash leads to load-switching impacts and increases noise emissions by more than 10 dB(A). The inspection is conducted strictly as soon as the wear protection provided by hardened gear pairs is compromised, in order to prevent tooth breakage.

The starting point is the coaxial alignment between the drive shaft and the pump shaft via an SAE or ISO flange. This ensures that a radial misalignment of ＞ 0.05 mm—which would place a one-sided load on the seal lip—is avoided. Otherwise, this would result in premature seal failure; we therefore primarily rely on gear shaft connections without transverse forces.

The most important criterion is the match between flow rate and viscosity. In addition, the mechanical design requires that the safety valve set pressure be matched to the maximum housing pressure. Incorrect design can result in the housing bursting in the event of blockages; therefore, our project engineers always perform a detailed system analysis, including digital pressure monitoring.

The magnetic coupling provides a hermetic seal without dynamic sealing elements, thereby completely eliminating the risk of leakage when handling aggressive media. However, a loss of magnetic coupling due to overload results in an immediate stoppage of flow; we validate the maximum torque to ensure stable, low-pulsation flow even during sudden changes in viscosity.

If the speed is too high, the spaces between the teeth are not completely filled, especially with viscous additives. This leads to cavitation and a non-linear flow rate, resulting in a deviation from the formulation. We therefore often limit the speed of our precision pumps to values below 500 rpm to ensure the highest dosing precision.

At process temperatures up to 250 °C, the expansion of the components leads to significant changes in clearances. Materials such as 1.4404 stainless steel and special alloys must be precisely matched during the engineering phase, as an incorrect estimate will cause the pump to seize. HARTON project engineers validate the cold-run clearances individually based on the thermal load profile.

Manufacturing tolerances in the range of a few micrometers drastically reduce "slip," ensuring that the flow rate remains directly proportional to the rotational speed. Inaccurate manufacturing can lead to an inaccurate mixture; we therefore test every metering pump for volumetric drift under varying back pressure up to 100 bar.

In chemical process engineering, PTFE-based elastomers are often used to prevent the seal from becoming brittle or swelling due to aggressive media. The consequence of an incorrect choice is media leakage; therefore, our design often favors the use of a magnetic coupling to completely eliminate wear on the shaft seal.

Some additives are sensitive to mechanical shear. Optimized tooth profiles and relief grooves ensure gentle product handling that does not break molecular chains. Incorrect geometry can cause a change in the medium’s viscosity; we validate the shear rates using CFD simulation.

The analysis is based on the corrosion rate and mechanical wear of the bearing sleeves and uses material data and load profiles to predict maintenance intervals. One risk is crevice corrosion during shutdown; we validate specific flushing cycles for integration into process-critical systems.

We validate the gear tooth geometry at specified operating intervals. The inspection reveals chemical wear on the flanks, which compromises low-pulsation conveyance; a measurable threshold is an increase in backlash of ＞ 0.1 mm. Our quality assurance department documents these wear trends to ensure process quality.

Standardized interfaces, such as the SAE flange, ensure quick interchangeability and precise alignment, which reduces installation errors and ensures proper alignment of the keyed shaft. The result is higher system availability; we deliver our pumps ready for connection to common dosing systems.

The choice of material (e.g., Hastelloy or ceramic) is the primary determining factor. In addition, the design requires a hermetic shaft seal to protect the environment. An incorrect design can result in a housing breach due to corrosion; our project engineers therefore conduct a detailed chemical resistance test on all wetted parts.

A heatable pump with specially hardened gears and increased bearing clearances is required to compensate for pressures up to 350 bar and the high viscosity of the polymer melt. Undersizing leads to gear shaft failure; we validate torque transmission at maximum viscosity to ensure maximum process reliability.

Dead spaces lead to thermal degradation of the plastic, which causes color defects or "speckles" in the final product. That is why we rely on flow-optimized geometries and low-pulsation feeding to ensure a homogeneous melt quality.

In profile extrusion, pressure fluctuations lead to dimensional inaccuracies. The helical gearing ensures an absolutely constant discharge pressure and thus greater profile accuracy; in contrast to spur gearing, we achieve a layer thickness tolerance in the micrometer range.

Fiberglass acts as an abrasive on the gear teeth. A PVD coating protects the gear-displacement units from rapid pressure loss; coated gears increase service life by a factor of 5 compared to standard steel.

The monitoring system dynamically regulates the contact pressure of the bearing plates and prevents metal-to-metal contact at high melt temperatures despite the presence of axial forces. Incorrect control leads to pump seizure; HARTON technicians check the compensation forces during hot testing.

At processing temperatures above 300 °C, the target gap dimensions are not reached until the system is in operation, which ensures optimal internal sealing without the risk of jamming. We provide specific heating profiles to prevent operating errors during startup.

The servo-motor-driven control system allows for precise flow rate control synchronized with the main screw, for example, for the accurate metering of liquid paints. To this end, our technicians integrate high-resolution sensors for monitoring operating pressure and controlling rotational speed.

Thermal consistency is crucial, which is why integrated heating elements and optimized thermal insulation are standard features. We validate the heat distribution within the housing to prevent cold spots and, consequently, the risk of the adhesive solidifying.

We verify the profile accuracy of the teeth under a microscope after each production run. This inspection detects material wear caused by abrasive fillers; one risk is tooth fracture due to a sudden increase in pressure, which is why HARTON continuously documents the wear history.

The molten plastic serves, in part, to self-lubricate the bearing bush. Plain bearings offer a larger bearing surface for high radial forces at high discharge pressure than needle roller bearings; we therefore primarily rely on specially treated plain bearings to ensure maximum service life.

A heatable pump with specially hardened gears and increased bearing clearances is required to compensate for pressures up to 350 bar and the high viscosity of the polymer melt. Undersizing leads to gear shaft failure; we validate torque transmission at maximum viscosity to ensure maximum process reliability.

Dead spaces lead to thermal degradation of the plastic, which causes color defects or "speckles" in the final product. That is why we rely on flow-optimized geometries and low-pulsation feeding to ensure a homogeneous melt quality.

In profile extrusion, pressure fluctuations lead to dimensional inaccuracies. The helical gearing ensures an absolutely constant discharge pressure and thus greater profile accuracy; in contrast to spur gearing, we achieve a layer thickness tolerance in the micrometer range.

Fiberglass acts as an abrasive on the gear teeth. A PVD coating protects the gear-displacement units from rapid pressure loss; coated gears increase service life by a factor of 5 compared to standard steel.

The monitoring system dynamically regulates the contact pressure of the bearing plates and prevents metal-to-metal contact at high melt temperatures despite the presence of axial forces. Incorrect control leads to pump seizure; HARTON technicians check the compensation forces during hot testing.

At processing temperatures above 300 °C, the target gap dimensions are not reached until the system is in operation, which ensures optimal internal sealing without the risk of jamming. We provide specific heating profiles to prevent operating errors during startup.

The servo-motor-driven control system allows for precise flow rate control synchronized with the main screw, for example, for the accurate metering of liquid paints. To this end, our technicians integrate high-resolution sensors for monitoring operating pressure and controlling rotational speed.

Thermal consistency is crucial, which is why integrated heating elements and optimized thermal insulation are standard features. We validate the heat distribution within the housing to prevent cold spots and, consequently, the risk of the adhesive solidifying.

We verify the profile accuracy of the teeth under a microscope after each production run. This inspection detects material wear caused by abrasive fillers; one risk is tooth fracture due to a sudden increase in pressure, which is why HARTON continuously documents the wear history.

The molten plastic serves, in part, to self-lubricate the bearing bush. Plain bearings offer a larger bearing surface for high radial forces at high discharge pressure than needle roller bearings; we therefore primarily rely on specially treated plain bearings to ensure maximum service life.

For high-precision fortification of animal feed or food products, we use precision pumps made of electropolished stainless steel, which enable exact dosing through defined volumes per revolution. We validate the dosing accuracy to within less than 0.3% deviation.

Emulsions such as dressings often must not be subjected to shear. Low rotational speeds and optimized profiles ensure gentle product handling without separation; choosing the wrong design can result in an unstable product, which is why we validate the shear rates during the design phase.

Liquid fertilizers often contain aggressive salts or acids, against which only 1.4404 stainless steel offers lasting resistance to pitting corrosion. Standard steel would lead to rapid deterioration of the shaft seal, which is why we use only certified materials.

In high-speed packaging machines, helical teeth prevent tears in the adhesive film caused by pressure fluctuations and ensure a secure bond at high cycle rates. This reduces waste and ensures a perfectly consistent application profile.

This monitoring system maintains a stable internal pressure while minimizing dead spaces where food residue could accumulate. This improves cleanability; HARTON technicians check for leaks as part of the certification process, taking hygiene considerations into account.

Although fats are often pumped at temperatures as low as 60 °C, the heating phase is critical. The material combination (e.g., stainless steel vs. bronze) must be selected so that the pump does not seize up even if the temperature limit is exceeded; for this purpose, we supply units with an integrated heating jacket.

A common drive shaft allows different active ingredients to be dispensed in proportion to the travel speed and reduces the space required on the agricultural machine. We validate the synchronization of the stages to ensure a precise mixture.

"Cleaning in Place" requires dead-space-free screw connections and durable O-rings that allow for residue-free disinfection. We validate cleanability through wetting tests to rule out microbiological risks.

We assess signs of wear using mineral additives. The test reveals abrasive wear on the tooth flanks; one risk is that the dosing rate may drop below the required minimum, which is why HARTON documents the loss of performance to aid in maintenance planning.

Precise control of even the smallest angular increments of the toothed shaft enables pinpoint-accurate injection and adjusts the amount of flavoring to fluctuating main flows. This ensures high product consistency; to achieve this, our technicians integrate fast control algorithms into the overall system.

To handle oils with an unknown particle content, we use robust pumps with hardened shafts. A reduced speed minimizes wear caused by abrasion; we validate their resistance to solids up to 0.2 mm to ensure continuous operation.

The gentle, volumetric conveyance of the oil-water mixture prevents emulsification of the phases due to low turbulence. Unlike centrifugal pumps, this method of transport preserves the droplet structure, which significantly improves separation efficiency.

Chemical decomposition products in used oils have a corrosive effect on bearing materials, leading to shaft deflection and one-sided flank wear. HARTON engineers therefore primarily rely on plain bearings made of chemical-resistant engineering plastics.

When feeding filter presses under increasing pressure, the helical teeth prevent vibrations in the flexible hoses, thereby protecting the filter cloths from mechanical overload. This extends the service life of the wear parts while ensuring a steady pressure build-up.

Sensors measure the axial position of the bearing plates and provide data on wear on the end faces of the gears. This enables predictive maintenance before a failure occurs and optimizes plant availability.

Since waste management facilities often handle unknown mixtures, the use of high-performance plastics such as Kalrez is necessary. To ensure maximum protection against leaks, our design for these pumps often also incorporates a magnetic coupling.

The integration of coarse and fine filtration into a single unit via a common drive shaft enables both stages to operate synchronously. This results in a compact design for the filtration system; we validate the power consumption of each stage accordingly.

During energy recovery, oils are often heated to high temperatures. Gray cast iron housings and stainless steel shafts must be designed so that the clearance dimensions are minimal at 200 °C, which maximizes efficiency. We provide specific material certificates for this purpose.

We test the surface condition of the teeth for pitting caused by acid exposure. The test reveals chemical and mechanical wear; one risk is the failure of the gear-displacer unit during sudden load changes, which is why HARTON documents the wear curves.

The precise dosing of acids or alkalis based on the pH value requires extremely small strokes for fine-tuning. To achieve this, our technicians integrate high-frequency control interfaces into the environmental control system to ensure pinpoint neutralization.