HDS 64 D OMFB Bent Axis Piston Motor 63.56cc 350 bar

Product Overview

The HDS 64 D is the 64 cc-class core model within the OMFB HDS series of bent-axis fixed displacement axial piston pumps/motors, product code 60100110643 (old code 108-015-06035). The OMFB HDS series features a bent-axis tapered piston rotary group design with fixed displacement, for use as either pump or motor in open hydrostatic drive circuits. The series spans displacements from 12 to 130 cm³/rev, with maximum continuous working pressure of 350 bar and peak pressure of 400 bar.

About OMFB and the HDS Series: OMFB is a renowned Italian hydraulic manufacturer. Its HDS series bent-axis piston pumps/motors are specifically designed for truck PTO (Power Take-Off) drives and high-load mobile hydraulic systems, widely deployed in tipper trucks, cranes, and construction machinery. The HDS series features a seven-piston design combined with a new internal gear machining method that significantly reduces operating noise. The compact ductile iron body delivers excellent resistance to pressure peaks (up to 400 bar), matching the ever-increasing working pressures of modern machines.

Model Code Breakdown (for procurement and engineering reference):

• HDS: OMFB bent-axis fixed displacement piston pump/motor series

• 64: Nominal size, geometric displacement 63.56 cm³/rev

• D: Right-hand rotation (clockwise, viewed from shaft end, Destra)

• ISO: Mounting flange per ISO 7653 standard, 4-hole, Ø80 mm

• 60100110643: Current OMFB product code

• 108-015-06035: Previous OMFB product code

Drop-in Interchangeability: The HDS 64 D can be directly installed as a replacement for Parker F1-61, Rexroth A17FO, Sunfab SCP, and similar bent-axis piston pumps, with fully matching mounting flange (ISO 7653 4-hole Ø80 mm) and shaft (DIN 5462 8x32x36). Every pump undergoes 100% simulated load testing prior to shipment, validating 350 bar pressure loading, volumetric efficiency, and thermal stability under conditions replicating real-world duty cycles.

Technical Specifications 

Model HDS 64 D ISO 60100110643:

• Model Code: HDS 64 D ISO 60100110643 (old code 108-015-06035)

• Series: OMFB HDS Series (Bent-Axis Fixed Displacement Pump/Motor)

• Nominal Size: 64

• Geometric Displacement: 63.56 cm³/rev

• Number of Pistons: 7

• Maximum Continuous Pressure: 350 bar (P1)

• Maximum Peak Pressure: 400 bar (P3)

• Maximum Speed (No Load): 2700 rpm

• Maximum Speed (With Load): 1900 rpm

• Maximum Intermittent Speed: 2500 rpm

• Minimum Speed: 300 rpm

• Maximum Output Torque (Δp = 350 bar): Approx. 354 N·m

• Mounting Flange: ISO 7653 standard, 4-hole, Ø80 mm

• Shaft: DIN 5462 standard, 8x32x36 (ISO 14 involute spline)

• Rotation: Right-hand (clockwise, viewed from shaft end)

• Port Connections: BSP threaded, pressure port G 3/4″, suction port G 1-1/4″

• Housing Material: Ductile Iron (Ghisa Sferoidale)

• Seal Material: FKM (fluororubber), capable of withstanding back pressures

• Operating Temperature: -40°C to +140°C

• Weight: Approx. 12.01 kg

HDS Series Displacement Size Reference:

• HDS 12: 12.62 cm³/rev, max speed 3000 rpm

• HDS 17: 17.00 cm³/rev, max speed 3000 rpm

• HDS 25: 25.00 cm³/rev, max speed 2700 rpm

• HDS 34: 33.80 cm³/rev, max speed 2300 rpm

• HDS 40: 40.00 cm³/rev, max speed 2300 rpm

• HDS 47: 47.13 cm³/rev, max speed 2700 rpm

• HDS 55: 56.70 cm³/rev, max speed 2700 rpm

• HDS 64: 63.56 cm³/rev, max speed 2700 rpm (no load) / 1900 rpm (with load)

• HDS 84: 84.00 cm³/rev, max speed 2300 rpm

• HDS 108: 107.00 cm³/rev, max speed 1800 rpm

• HDS 130: 130.00 cm³/rev, max speed 1500 rpm

Key Technical Advantages

1. Bent-Axis Design with Low Noise Operation
The HDS series employs a bent-axis tapered piston rotary group design where the piston axis is angled relative to the drive axis. The lateral force exerted by pistons on the cylinder block is minimal, and combined with a new internal gear machining method, the mechanical coupling between the cylinder block and driving gear is significantly improved, achieving maximum performance at an extremely low noise level. The seven-piston structure ensures balanced bearing load distribution, delivering smoother output flow with less pulsation.

2. Compact Ductile Iron Body with High Pressure Resistance
The pump body is precision-cast from ductile iron (spheroidal graphite cast iron). The compact design reduces overall dimensions while enhancing the body’s resistance to pressure peaks (up to 400 bar). The nodular graphite structure of ductile iron provides higher tensile strength and fatigue limit compared to flake graphite cast iron, while maintaining excellent damping characteristics.

3. Hardened Shaft with Reinforced Sealing System
The output shaft features hardened spline treatment, providing enhanced resistance to the torque transmitted by the PTO. The sealing system utilizes FKM (fluororubber) material with reinforced design, allowing the pump to withstand back pressures. Special gaskets enable the pump to operate over a wide temperature range from -40°C to +140°C.

4. Long-Life Bearing System with 3-Piece Body Construction
The drive shaft employs tapered roller bearings, which offer greater load capacity compared to ball bearings, capable of withstanding high loads under 350 bar continuous working pressure. The 3-piece body construction ensures constant bearing lubrication, effectively extending maintenance intervals and service life.

5. Contamination-Resistant Sliding Surfaces with Tapered Gear Drive
The sliding surfaces use aluminum and nitrated cast iron pairing, ensuring longer service life even in contaminated hydraulic fluid conditions. The cylinder block is driven by the shaft through a proven tapered toothing, freeing pistons from any radial load during operation for improved fatigue resistance.

6. Drop-in Interchangeability with By-Pass Valve Option
The HDS 64 D can be directly installed as a replacement for Parker F1-61, Rexroth A17FO63, Sunfab SCP, and similar mainstream bent-axis piston pumps, with fully matching mounting flange and shaft dimensions requiring no adaptation. The by-pass valve option is primarily used in applications where the pump is permanently driven (e.g., mounted directly on the engine or PTO without clutch disengagement), enabling unloaded circulation without stopping pump rotation.

Application Areas

• Truck PTO Drives: Tipper truck hydraulic tipping systems, truck-mounted cranes, refuse compactors (the core application of the HDS series)

• Construction Equipment: Excavators (Komatsu PC450-8, CAT 336E, Hitachi ZX470, Volvo EC950F), loaders (JCB 3CX, Manitou MLT 841), bulldozers

• Agricultural Machinery: High-horsepower tractors (John Deere 8430, Fendt 718 Vario, Massey Ferguson 7622), combine harvesters

• Lifting Equipment: Mobile cranes (Liebherr LTM 1050-3.1, Terex Demag AC 100-4L), lorry loaders

• Forestry Machinery: Forestry harvesters and forwarders (Caterpillar 577G, Tigercat 726E)

• Marine & Offshore: Deck machinery hydraulic drives, marine winches

• Material Handling: Forklift hydraulic systems, lift platform hydraulic drives

Expert Maintenance Tips

1. Hydraulic Fluid Cleanliness
OMFB recommends maintaining hydraulic fluid cleanliness at NAS Grade 8 (ISO 4406 18/15/12) or better, with contaminant particle size not exceeding 10 μm. While the HDS series employs aluminum/nitrated cast iron sliding surfaces for enhanced contamination tolerance, long-term operation in highly contaminated fluid will accelerate valve plate wear. Replace filter elements at 500 hours after first commissioning, then every 1,000 operating hours or 6 months, whichever comes first.

2. Rotation Direction Adjustment
The rotation direction of the HDS 64 D can be adjusted by rotating the rear cover 180°, without replacing the pump body or internal components, adapting to different PTO output shaft rotation directions. After adjustment, reconfirm that port positions and drain port orientation are correct.

3. Installation Alignment and Coupling Requirements
Ensure drive shaft alignment during installation, employing a flexible coupling to avoid bending or thrust stress. Maximum permissible misalignment is less than 0.1 mm TIR and maximum permissible misangularity is less than 0.2°. Apply appropriate grease to the spline connection to prevent fretting wear.

4. Pre-Start Priming and Air Bleeding
Before first start, fill the pump housing with clean hydraulic fluid through the case drain port. After installation, turn the drive shaft by hand several revolutions to confirm free rotation without binding. Start at low speed with zero load and run for 5–10 minutes. Verify continuous bubble-free flow from the case drain. Only then apply load.

5. Operating Temperature and Viscosity Control
The HDS series operating temperature range is -40°C to +140°C, accommodating extreme environments. Recommended fluids are ISO VG32 or VG46 anti-wear hydraulic oils with an optimum viscosity range of 17–180 cSt. The case drain line must return directly to the reservoir with back pressure not exceeding 2 bar.