A helical gear pump replaces the straight spur teeth of a standard external gear pump with helical tooth profiles — the progressive tooth engagement across the full gear face width reduces pressure pulsation by 60–80% and airborne noise by 10–15 dB(A) vs. equivalent spur gear pumps. Processing 0.5–600 m³/h at 1–500,000 cP and pressures up to 150 bar, it is the preferred tooth wheel pump for continuous precision metering, noise-sensitive environments, and applications where pulsation causes downstream process quality issues.
Challenges
Axial Thrust Load from Helical Tooth Geometry (Single-Helical)
Single-helical gears generate net axial thrust on the shaft — requires thrust bearings; increases bearing load.
More Complex Manufacturing than Spur Gears (Higher Unit Cost):
Helical hob cutting and accurate helix angle control is more complex — manufacturing cost 30–50% above equivalent spur pump.
Gear Contact Length Sensitivity to Misalignment
Helical gear tooth contact is sensitive to shaft deflection and misalignment — edge loading reduces tooth and bearing life.
Suction Performance at Very High Viscosity (>100,000 cP)
At extreme viscosity, fluid cannot fill the helical tooth space fast enough at rated speed — cavitation and suction starvation.
Seal Complexity at High Axial Thrust (Thrust Bearing + Mechanical Seal Interaction)
Thrust bearing reaction changes mechanical seal face loading — seal must be designed for combined radial and axial loading.
Solutions
- Double-Helical (Herringbone) Gear Design (Cancels Axial Thrust): Opposed helix halves cancel axial thrust — eliminates thrust bearing requirement; simplified seal design.
- Near-Net-Shape Gear Hobbing with CNC Grinding (±0.005 mm Tooth Profile): CNC ground helical profile achieves tight tooth accuracy — reduces noise below spur gear level at equivalent speed.
- Flexible Coupling + Rigid Shaft Alignment Protocol (±0.05 mm TIR): Flexible coupling and precision alignment reduce misalignment below 0.05 mm TIR — protects tooth contact pattern.
- Reduced Speed at High Viscosity (VFD, Speed Proportional to Fill-Rate Limit): VFD reduces speed to match fluid fill-rate at extreme viscosity — prevents cavitation while maintaining flow.
- Cartridge Mechanical Seal (Axial + Radial Compensation, Pre-Set Compression): Cartridge seal pre-sets compression — compensates combined axial and radial load without field adjustment.
Applications
- Pharmaceutical: Precision API metering, infusion pump priming, filling line precision dosing — low pulsation critical.
- Chemical: Polymer melt precision metering in extrusion lines — pulsation causes gauge variation in extrudate.
- Printing & Inks: Ink and varnish metering to print heads — pulsation directly affects print density and colour.
- Hydraulics: Hydraulic power unit supply pump — low noise and pulsation required in precision motion control.
- Food & Beverage: Precision liquid food metering and portion control — flow accuracy ±0.5% for dosing applications.
Models & Capacities
Type 1C — Helical Gear Pump (Low-Noise, Low-Pulsation): Models & Capacities | ||||||||||||
Model | Type | Flow Rate [L/min] | Flow Rate [m³/h] | Gear Ø [mm] | Helix Angle [°] | Speed [RPM] | Max Pressure [bar] | Max Viscosity [cP] | Noise at 1 m [dB(A)] | Motor [kW] | Inlet/Outlet Ø [mm] |  |
HGP-025-SH | Single-Helical | 1–10 | 0.06–0.6 | Ø25 | 15° | 50–1,450 VFD | 80 | 500,000 | <60 | 0.18 | DN 10 |  |
HGP-040-SH | Single-Helical | 3–30 | 0.18–1.8 | Ø40 | 15° | 50–1,450 VFD | 100 | 500,000 | <62 | 0.37 | DN 20 |  |
HGP-063-SH | Single-Helical | 8–80 | 0.5–4.8 | Ø63 | 15° | 50–1,450 VFD | 120 | 500,000 | <65 | 0.75 | DN 25 |  |
HGP-100-SH | Single-Helical | 20–200 | 1.2–12 | Ø100 | 15° | 50–1,450 VFD | 150 | 500,000 | <68 | 1.5 | DN 40 |  |
HGP-125-DH | Double-Helical | 40–350 | 2.4–21 | Ø125 | 20° | 50–1,200 VFD | 150 | 500,000 | <65 | 2.2 | DN 50 |  |
HGP-160-DH | Double-Helical | 70–600 | 4.2–36 | Ø160 | 20° | 50–1,000 VFD | 150 | 500,000 | <65 | 3.0 | DN 65 |  |
HGP-200-DH | Double-Helical | 120–1,000 | 7.2–60 | Ø200 | 20° | 50–900 VFD | 150 | 500,000 | <68 | 5.5 | DN 80 |  |
HGP-250-DH | Double-Helical | 200–1,800 | 12–108 | Ø250 | 20° | 50–750 VFD | 150 | 500,000 | <68 | 7.5 | DN 100 |  |
HGP-315-DH | Double-Helical | 400–3,500 | 24–210 | Ø315 | 20° | 30–600 VFD | 150 | 500,000 | <70 | 11 | DN 125 |  |
HGP-400-DH | Double-Helical | 700–6,000 | 42–360 | Ø400 | 20° | 20–500 VFD | 150 | 500,000 | <70 | 18.5 | DN 150 |  |