HYDM282M Hydraulic Motor | 1.72 cid Marzocchi

HYDM282M Marzocchi LSHT Hydraulic Motor

System Role & Intended Use

• Marzocchi external-gear hydraulic motor with 1.72 in³/rev (≈28.2 cc/rev) displacement.
• Sized to deliver strong starting torque and smooth, steady operation for small to mid-frame Annovi Reverberi (AR) triplex plunger pumps.
• Designed for direct hydraulic drive where belt systems are undesirable due to space, maintenance, or alignment concerns.
• Optimized for compact wash skids, service bodies, trailers, and plant carts with existing hydraulic power.

Motor Architecture & Operating Characteristics

• External-gear, low-speed/high-torque (LSHT) motor manufactured by Marzocchi.
• Displacement provides useful torque at moderate pressures without forcing excessive pump RPM.
• Smooth torque delivery supports stable pressure and calm trigger cycling.
• Round-body form factor simplifies packaging in confined equipment compartments.
• Consistent rotational stability reduces vibration compared with belt-driven layouts.

HYDM282M Mounting & Alignment Strategy

• Intended for coaxial mounting with the AR pump on a shared rigid base.
• Shared centerline minimizes side loading on pump bearings and seal packs.
• Alignment-stable geometry helps the assembly run cooler and quieter over long duty cycles.
• Close-coupled layout preserves access to coupling hardware, fasteners, oil sight glass, and vented dipstick.
• Perimeter space remains available for short suction runs and tidy pressure and bypass routing.

Hydraulic Ports & Circuit Requirements

• Typical ports for this motor class are SAE-12 ORB (3/4″) for pressure and return.
• Many builds include an SAE-8 ORB (1/2″) case drain; verify on the supplied motor.
• If present, the case drain must return to the reservoir above oil level and remain unrestricted.
• A/B port orientation must be observed so motor rotation matches pump rotation.
• Hose IDs must be generously sized and bend radii respected to avoid restriction and heat buildup.

HYDM282M Hydraulic Sizing & Shop Math

• Motor speed estimate: rpm ≈ 231 × hydraulic GPM ÷ displacement (in³).
• With 1.72 in³ displacement, speed is approximately 134 × hydraulic GPM.
• At 5 GPM, shaft speed is approximately 670 RPM.
• At 8 GPM, shaft speed is approximately 1,075 RPM.
• Torque estimate: lb-in ≈ displacement (in³) × PSI ÷ 6.283.
• At 2,500 PSI, estimated torque is approximately 685 lb-in.
• At 3,000 PSI, estimated torque is approximately 823 lb-in.
• Hydraulic power: HP ≈ GPM × PSI ÷ 1714; apply realistic system and motor efficiency.

Hydraulic Circuit Protection

• System relief valves must be set correctly for the intended operating pressure.
• 10–25 μm return filtration with an adequate beta rating is required.
• Reservoir volume should follow a practical rule of 2–3× total system flow.
• Oil cooling is recommended for hot climates, prolonged bypass, or continuous-duty operation.
• Hose routing must avoid sharp bends, restrictions, and unnecessary fittings.

Water-Side Plumbing Requirements

• Suction plumbing must be short, straight, and oversized from a flooded source.
• Anti-collapse suction hose and a coarse inlet strainer are required to prevent cavitation.
• An adjustable unloader matched to the AR duty class is required.
• A correctly sized high-pressure relief valve is required for safety.
• A glycerin-filled pressure gauge is required for commissioning and diagnostics.
• A thermal relief valve is required on the bypass loop for extended gun-closed operation.

HYDM282M Compatible AR Pump Classes

• Well suited for small to mid-frame AR triplex pumps in the 3–5.5 GPM range.
• Typical operating pressures range from 1,000–2,900 PSI.
• Applications favor smooth pressure response over extreme flow rates.
• Pump selection must always respect published maximum RPM limits.

HYDM282M Hydraulic Motor | 1.72 cid Marzocchi

Service Access & Reliability

• Close motor-to-pump spacing preserves access to coupling hardware and service points.
• Single-technician maintenance is supported for coupling checks, oil changes, and torque verification.
• Rigid base geometry maintains alignment through transport, temperature changes, and rough service.
• Reduced vibration and side loading extend bearing and seal life.

Typical Applications

• Mobile wash skids on service trucks and trailers.
• Plant carts and conveyor-cell rinse stations.
• Municipal and DOT fleet maintenance facilities.
• Rental turn-back equipment and equipment yards.
• Building services and contractor systems with existing hydraulic power.

HYDM282M Hydraulic Motor | 1.72 cid Marzocchi

System Advantages

• Direct hydraulic drive eliminates belts, belt dust, and retensioning.
• Compact footprint supports clean, repeatable OEM builds.
• Smooth LSHT torque delivers stable pressure and calm trigger cycling.
• Predictable hose routing simplifies documentation and future service.
• Professional, alignment-stable layout improves lifecycle cost and uptime.