HYDM-DF-044-RTX60-70 Hydraulic Motor | 44 cc Danfoss

HYDM-DF-044-RTX60-70 | 44cc Hydraulic Gear Motor | For RTX60 & RTX70 Direct Drive Pumps

HYDM-DF-044-RTX60-70 is the drive half of the direct-drive equation: a 44cc external gear hydraulic motor with the male 13-tooth splined shaft (SAE B) that slides straight into the hollow spline of Annovi Reverberi’s RTX-class DD pumps. WSHPWR sells the RTX60-DD and RTX70-DD as pump-only units precisely so builders can match the motor to their circuit — and for hydraulic systems in the moderate-flow, higher-pressure band, this 44cc displacement is the match: full 1450 RPM pump speed from roughly 18.8 GPM of oil, with working pressure to drive the pumps toward their ratings.

The 44cc sizing occupies the practical middle of the pairing chart. Where the 90cc gear motor wants a flow-rich 37.5 GPM circuit and the small piston options want pressure headroom most mobile systems lack, the 44cc runs the RTX70.200 at its AR-published operating point — 240 bar (3,481 PSI) of oil at 71 L/min (18.8 GPM) — numbers that strong truck hydraulic systems and dedicated power units deliver every day. One motor, bolted once, completing the pump you already chose.

HYDM-DF-044-RTX60-70 Specifications

• SKU: HYDM-DF-044-RTX60-70
• Configuration: Hydraulic gear motor — companion drive for RTX-class hollow-spline DD pumps
• Type: External gear motor
• Displacement: 44cc (2.69 in³) per revolution
• Output Shaft: Male 13-tooth spline, SAE B (SAE J498 B101) — engages RTX DD hollow shafts directly
• Mounting: SAE B 2-bolt, mates to the pump’s F56-class flange
• Oil Flow for 1450 RPM: Approximately 71 L/min (18.8 GPM)
• Reference Working Pressure: 240 bar (3,481 PSI) per AR’s published RTX 70.200 pairing
• Compatible Pumps: HYD-RTX60-DD, HYD-RTX70-DD, and the RTX 60.300 / 70.200 DD platform family

Sizing: HYDM-DF-044-RTX60-70 Why 44cc Fits These Pumps

Displacement sets the flow-for-speed trade, and the arithmetic is unforgiving: RPM ≈ 231 × hydraulic GPM ÷ displacement (in³). At 2.69 in³, reaching the pumps’ 1450 RPM rated speed takes about 18.8 GPM of oil — while the same shaft turned by a 90cc motor would demand nearly double the flow, and a 34cc piston would need only 14.5 GPM but at pressures above many circuits’ comfort. For the RTX70.200’s 35 HP duty, AR publishes this exact pairing; for the RTX 60.300’s stronger 45 HP appetite, the 44cc runs the pump to the limit of your circuit’s pressure — verify your system delivers the working pressure your target duty point demands, and call WSHPWR with your flow, pressure, and relief numbers for the match before ordering.

Completing the DD Pump — Correctly

The direct-drive architecture only pays off when the motor is right: the male spline engages the pump’s hollow female shaft on one centerline through the flange, with no coupler, no belt, no alignment procedure, and no side load reaching either component’s bearings. Getting there requires three matches this motor is built to make — spline count (13T; the 14T SAE C motors from RTD-class systems will not engage), mount pattern (SAE B 2-bolt to the F56-class flange), and displacement sane for the circuit. Buy the pump and this motor together and the drive arrives matched; retrofit it onto a DD pump already in service and the swap is four bolts and two hoses.

Gear Motor Simplicity

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 — a two-line pressure-and-return hookup that keeps cabinet and deck installations clean. Service demands are essentially clean, filtered oil; protect the motor with a relief set at its rating and it will outlast several sets of pump seals.

HYDM-DF-044-RTX60-70 Installation & Operation Notes

Confirm rotation direction against your pump before plumbing — gear motors are rotation-specific, and reversed pressure and return lines spin the pump backward. Torque the two mounting bolts to spec with the spline fully engaged, keep the relief at or below the motor’s rating, route the return short and filtered to tank, and provide oil cooling sized for continuous washdown or jetting duty. At commissioning, verify 1450 RPM at the pump (flow ÷ displacement math or a phototach) — never overspeed the pump chasing output.

Quality Assurance

Every HYDM-DF-044-RTX60-70 is verified for fitment against the RTX DD spline and flange interface. Pair with the matching pump at order time and WSHPWR confirms the complete drive against your circuit’s numbers — flow, pressure, relief, and cooling — before anything ships.

HYDM-DF-044-RTX60-70 Key Features & Applications

• 44cc gear motor with male 13T SAE B spline — direct engagement with RTX60-DD and RTX70-DD hollow shafts.
• Turns the pumps at their rated 1450 RPM on approximately 18.8 GPM of oil.
• AR-published operating point on the RTX 70.200: 240 bar at 71 L/min.
• Two-line hookup, no case drain, essentially maintenance-free gear architecture.
• Four bolts and two hoses to complete or repower a DD pump already in service.
• Ideal for hydrovac and jetter builds, washdown skids, and OEM systems completing an RTX direct-drive pump purchase.