HYDM-SF-084W-SAE-RTD80 Hydraulic Motor | 84 cc Sunfab

HYDM-SF-084W-SAE-RTD80 | Sunfab 84cc Piston Motor | SAE C 14T | For RTD80 Hydraulic Pumps

HYDM-SF-084W-SAE-RTD80 is the piston half of the hydrovac equation: a Sunfab SCM 084W bent-axis piston motor in SAE configuration — SAE C mount with the male 14-tooth splined shaft that slides directly into the hollow spline of Annovi Reverberi’s RTD-class direct-drive pumps. This is the drive the RTD80.300 family was engineered around: Annovi Reverberi’s own pairing charts specify a piston 84cc motor for the RTD platform, and this Sunfab is that displacement in the mount and spline the pumps accept.

The brand matters at this power level. Sunfab of Hudiksvall, Sweden, has built bent-axis piston hydraulics for truck crane and mobile equipment duty for decades — precisely the continuous, high-pressure, all-shift service a hydrovac or jetter pump demands. Bent-axis piston architecture holds high efficiency at pressures gear motors cannot sustain, which is not a luxury here: driving 21 GPM of water at 4350 PSI simply requires oil pressure beyond the gear-motor world, and the SCM 084W is built to live there.

HYDM-SF-084W-SAE-RTD80 Specifications

• SKU: HYDM-SF-084W-SAE-RTD80
• Configuration: Bent-axis piston hydraulic motor — companion drive for RTD-class hollow-spline DD pumps
• Manufacturer: Sunfab (Sweden), SCM 084W
• Type: Fixed-displacement bent-axis piston motor
• Displacement: 84cc (5.13 in³) per revolution
• Output Shaft: Male 14-tooth spline, SAE C (SAE J744 C127) — engages RTD DD hollow shafts directly
• Mounting: SAE C flange, mates to the pump’s F57-class interface
• Oil Flow for 1000 RPM: Approximately 24.6 GPM (93 L/min)
• Pressure Capability: Piston-class — continuous ratings in the 350 bar class, per Sunfab SCM specifications
• Compatible Pumps: HYD-RTD80.300HN-DD, HYD-RTD-HW80.300HN-DD, HYD-RTDSS80.300HN-DD, and the RTD DD platform family

Why Piston, Not Gear

The RTD80.300’s full duty — 21 GPM at 4350 PSI of water — consumes roughly 70 hydraulic horsepower, which at this motor’s 24.6 GPM oil appetite means working pressures in the 4,200 to 4,850 PSI band on the oil side. That is beyond gear-motor territory as a matter of physics, not preference: external gear motors surrender efficiency and life rapidly above their pressure class, while bent-axis piston motors are designed for it, converting oil to shaft power at efficiencies gear designs never reach. AR’s published pairing HYDM-SF-084W-SAE-RTD80 for the RTD class runs this displacement at 314 bar (4,554 PSI) and 93 L/min on the adjacent RTD 100.210 — the operating neighborhood this Sunfab calls home. Verify your power unit sustains the flow and pressure continuously, relieve the circuit within the motor’s rating, and call WSHPWR with your system’s numbers for the match before ordering.

Completing the RTD Pump — Correctly

Direct drive at 70 horsepower rewards exactness: the male 14T spline engages the pump’s hollow shaft on one centerline through the SAE C flange — no coupler, no alignment procedure, no side load reaching either component — but only when the three matches hold. Spline count: 14T; the 13T SAE B motors from RTX-class systems will not engage. Mount: SAE C to the RTD’s F57-class interface. Displacement: 84cc lands the pump at its 1000 RPM rating on ~24.6 GPM of oil — never overspeed an RTD, and displacement is what enforces that. Ordered with the pump, the pair ships verified; ordered as a repower, WSHPWR confirms your pump’s interface first.

HYDM-SF-084W-SAE-RTD80 Built for the Duty That Kills Lesser Drives

Hydrovac and jetting duty is the hardest service in mobile hydraulics: full-pressure, trigger-on operation for shifts at a time, hot oil, and a power level where every inefficiency becomes heat the cooler must remove. Bent-axis piston construction earns its price here — high starting torque to spin a loaded pump, sustained high-pressure capability, and service life measured in years of daily duty. Protect it with a correctly set relief and honest return filtration, and this motor typically outlasts multiple pump wet-end services.

Installation & Operation Notes

Confirm rotation direction against your pump before plumbing. Seat the 14T spline fully and torque the SAE C mounting hardware to spec. Set the circuit relief within the motor’s rating, route the return generously and filtered to tank, and size oil cooling for continuous duty at this power level — at 70 hydraulic horsepower, cooling is a design item, not an accessory. At commissioning, verify 1000 RPM at the pump; the RTD platform’s slow-speed durability depends on holding it.

Quality Assurance

Every HYDM-SF-084W-SAE-RTD80 is verified for fitment against the RTD DD spline and flange interface before shipment. Sunfab’s SCM series carries the manufacturer’s own factory testing and documentation, and WSHPWR confirms the complete drive — flow, pressure, relief, and cooling — against your power unit’s numbers when you order the pair.

HYDM-SF-084W-SAE-RTD80 Key Features & Applications

• Sunfab SCM 084W bent-axis piston motor — the piston 84cc displacement AR’s RTD pairing charts specify.
• Male 14T SAE C spline engages RTD80.300-family DD pumps directly; F57-class flange mount.
• Turns the pump at its rated 1000 RPM on approximately 24.6 GPM of oil.
• Piston-class pressure capability for the 4,200+ PSI oil-side duty gear motors cannot sustain.
• The repower path for fielded RTD systems — and the correct first build for new ones.
• Ideal for hydrovac trucks, sewer jetters, and industrial high-pressure systems completing an RTD direct-drive pump.