HYD-RK1520M Hydraulic Motor Pump Package | Marzocchi

HYD-RK1520M | Hydraulic Motor Pump Package | Marzocchi Gear Motor | 4.0 GPM 3000 PSI

HYD-RK1520M Hydraulic Motor Pump Package couples the Annovi Reverberi RK 15.20 H triplex plunger pump with a close-mounted Marzocchi gear motor — rated at 4.0 GPM and up to 3000 PSI (206 bar) at 1450 RPM per AR North America’s published specifications. Marzocchi Pompe of Bologna has built external gear pumps and motors since the 1950s, and pairing that gear motor directly onto AR’s F38 flange produces one of the most compact, mechanically simple hydraulic drive units in the RK line: two hydraulic lines in, high-pressure water out, nothing else to align, tension, or maintain.

The HYD-RK1520M is the Marzocchi-motor alternative to the Sauer Danfoss-equipped HYD-RK1520 — the same proven RK 15.20 H pump and duty point, with a gear-motor drive whose displacement options let you match the package to your machine’s hydraulic character: high-flow/lower-pressure circuits or low-flow/higher-pressure circuits both have a factory pairing.

HYD-RK1520M Specifications

• SKU: HYD-RK1520M
• Configuration: Hydraulic motor + pump package — Marzocchi gear motor close-coupled to the pump
• Pump: Annovi Reverberi RK 15.20 H solid-shaft triplex plunger pump (228-series frame)
• Flow Rate: 4.0 GPM (15.1 L/min)
• Maximum Discharge Pressure: 3000 PSI (206 bar), per AR North America
• Rated Speed: 1450 RPM
• Pump Power Requirement: 7.5 HP (5.6 kW) at full duty, per AR’s published rating
• Hydraulic Motor: Marzocchi external gear motor, direct-mounted via F38 close-couple flange (SAE A 82.55)
• Hydraulic Hookup: Two-line pressure and return connection
• Pump Inlet Ports (2): 1/2″ F
• Pump Discharge Ports (2): 3/8″ F
• Maximum Fluid Temperature: 140°F
• Pump Head: Brass, with one-piece ceramic plungers

Hydraulic Supply Requirements — Match the Gear Motor to Your Circuit

Annovi Reverberi publishes two factory gear-motor pairings for the RK 15.20 H pump, and the right one depends on what your auxiliary circuit delivers. The 19cc gear motor draws 31 L/min (8.2 GPM) of oil at 135 bar (1,958 PSI) — the fit for standard-flow skid steer, tractor, and truck circuits with flow to spare. The 11cc gear motor draws just 17 L/min (4.5 GPM) at 239 bar (3,466 PSI) — the fit for machines with limited auxiliary flow but strong pressure capability, a circuit profile common on cranes, aerial trucks, and smaller power units. Either way the HYD-RK1520M consumes roughly 10 to 11 hydraulic horsepower at the full 3000 PSI water duty point. Confirm your circuit relief protects the fitted motor’s rating, keep the return line short and low-restriction back to tank, specify return filtration, and provide oil cooling for extended continuous-duty washing. If available flow runs slightly below spec, the HYD-RK1520M simply runs proportionally slower — full rated water pressure still requires full supply pressure at the motor. Call WSHPWR with your machine’s auxiliary flow and pressure and we will confirm which gear motor displacement your application needs.

Why a Marzocchi Gear Drive

External gear motors are the simplest rotary drive in hydraulics: two gears, one housing, no internal valving to time and no case drain line to plumb. On the HYD-RK1520M that simplicity shows up as a compact, low-profile package with a straightforward two-line hookup, easy service access, and one less hose run through your cabinet or truck body. The gear motor bolts directly to the F38 flange on the pump centerline — no belts, pulleys, guards, or couplers — so side loading on bearings and seals stays minimal and cleaning performance remains independent of host engine speed. For integrators standardizing on gear-motor hydraulics across their equipment, the HYD-RK1520M keeps the washdown drive consistent with the rest of the machine.

Heavy-Duty RK-Series Construction

The RK 15.20 H pump at the core of the HYD-RK1520M carries a corrosion-resistant brass head with stainless-steel wet-end components, one-piece ceramic plungers for heat dissipation and abrasion resistance, and a pressed high-strength steel crankshaft on oversized bearings. The die-cast aluminum crankcase includes an oil sight glass for quick level checks, and intake and delivery valves sit behind service plugs in the head for inspection or replacement without dismounting the pump.

Installation & Operation Notes

Mount the HYD-RK1520M horizontally and confirm gear motor rotation before commissioning — gear motors are rotation-specific, and reversed pressure and return lines will spin the pump backward. Keep suction plumbing short and unrestricted with flooded suction preferred, pair the discharge with a properly sized unloader set against your working pressure, and choose nozzle orifices for the 4.0 GPM duty point. Check crankcase oil at the sight glass before first start, and winterize before cold-weather storage to protect the head and valves.

Quality Assurance & Maintenance

Every HYD-RK1520M is built around a factory-tested Annovi Reverberi pump verified for flow rate, pressure stability, and vibration before shipment. Routine maintenance follows the standard RK pattern — scheduled pump oil changes, seal inspection, and periodic valve checks with standard AR repair kits — and the gear motor itself is essentially maintenance-free beyond clean, filtered oil. The NPT-port AR26472 replacement pump covers the long-term repair path without repurchasing the drive.

HYD-RK1520M Key Features & Applications

• AR RK 15.20 H pump direct-coupled to a Marzocchi external gear motor — 4.0 GPM at 3000 PSI, 1450 RPM.
• Two published gear-motor displacements match high-flow or low-flow auxiliary circuits.
• Simple two-line hydraulic hookup with no case drain to plumb.
• F38 close-couple direct drive — no belts, pulleys, or couplers to maintain.
• Brass head, stainless wet-end components, and ceramic plungers for continuous duty.
• The HYD-RK1520M suits integrators standardizing on gear-motor hydraulics across their fleet.
• Ideal for crane and aerial trucks, skid steer and tractor washdown, service bodies, and OEM equipment where compact drive packaging matters.