OMR & OMS Series Radial Plunger Hydraulic Motors
(For Excavators, Drilling Rigs, Conveyors, and Other Heavy-Duty Equipment)
I. Product Overview
TheOMR and OMS Seriesareradial plunger hydraulic motorsdesigned forhigh-load, low-speed, high-torqueapplications. Featuring a multi-plunger radial distribution structure, they offer the following core advantages:
• High starting torque: Plunger design ensures smooth torque output, with starting torque up to120% of rated torque.
• Wide speed range: Operates from50–1500 rpm, adapting to low-speed crawling and high-speed rotation.
• Strong impact resistance: Rolling bearings support plungers, withstanding frequent shock loads (e.g., drilling, excavator slewing).
• Long service life: Key components (plungers, valve plates) usehigh-strength alloy steel, heat-treated to HRC55-60, with a lifespan exceeding10,000 hours.
Typical Applications:
• Excavator slewing mechanisms, travel drives
• Drilling rig spindle rotation, mud pump drives
• Conveyor roller drives, heavy-equipment steering
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II. Technical Specifications
【表格】
Parameter OMR Series OMS Series
Displacement (cc/rev) 50–500 (selectable) 80–800 (selectable)
Rated Pressure (MPa) 25 30
Peak Pressure (MPa) 35 40
Rated Speed (rpm) 50–1200 80–1500
Max Torque (N·m) 1200 (@50 rpm) 2000 (@80 rpm)
Weight (kg) 45–120 (by displacement) 60–180 (by displacement)
Port Size Input: SAE B 2-bolt/4-bolt Input: SAE C 4-bolt/6-bolt
Operating Temp Range -20°C to +80°C -20°C to +100°C
Key Performance Metrics:
• Volumetric Efficiency: ≥92% (rated conditions)
• Mechanical Efficiency: ≥90% (rated conditions)
• Total Efficiency: ≥83% (rated conditions)
• Backpressure Tolerance: Max10 MPa(requires drain line)
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III. Structural Features
1. Radial Plunger Distribution:
• Plungers are evenly distributed radially around the cylinder block, connected to a crankshaft via connecting rods forlow-speed, high-torque output.
• Plunger count:7–9 (OMR),9–11 (OMS). More plungers reduce per-plunger load, extending lifespan.
2. Optimized Valve Plate Design:
• Axial valve platewith hydrostatic balancing minimizes leakage. Adjustable valve angle (±15°) adapts to varying speeds.
• Valve plate material: Copper-based alloy (hard chrome-plated), 3× wear resistance.
3. Bearing System:
• Main Bearing: Double-row tapered roller bearings handle radial/axial loads (rated dynamic load:500 kN).
• Plunger Bearings: Needle roller + plain bearing combination reduces friction, cutting starting resistance by 40%.
4. Sealing Design:
• Shaft Seal: Dual-lip fluororubber seals withstand 120°C oil temps, IP67 rating.
• Housing Seal: O-ring + backup ring prevents high-pressure leakage.
5. Cooling Options:
• Natural cooling (standard) or forced air cooling (high-power models for continuous operation).
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IV. Performance Advantages
1. Low-Speed Stability:
• Minimum stable speed50 rpm, torque fluctuation ≤3%, ideal for slow drilling and conveyor starts.
2. Overload Capacity:
• Short-term overload (10 sec) handles150% rated pressure, suitable for excavator digging and drill jamming.
3. Bidirectional Rotation:
• Reversible by changing port connections, with equal torque in both directions (no need for directional valves).
4. Contamination Resistance:
• Valve clearance0.03–0.05 mm, tolerates NAS 8 (ISO 20/17) oil cleanliness for harsh environments.
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V. Typical Applications
1. Excavator Slewing Drives:
• Replaces planetary reducer + hydraulic motor combinations, directly driving slewing bearings.Response time reduced by 30%.
• Case Study: A 22-ton excavator with OMR-200 motor achieved slewing start time of0.8 sec(vs. 1.2 sec previously).
2. Drilling Rig Spindles:
• Provides0–300 rpm adjustable speedfor top-drive rigs, with stable torque for varying geology.
• Case Study: A 3000m drill rig with OMS-500 motor ran200 hourscontinuously without failure.
3. Conveyor Drives:
• Directly drives long-distance conveyor rollers, reducing intermediate transmissions by 15% efficiency.
• Case Study: A coal mine conveyor with OMR-150 motor saved120,000 kWh/year.
4. Marine Steering:
• High-torque steering for large vessels, withstanding waves and achieving±0.5° accuracy.
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VI. Selection & Installation Guidelines
1. Sizing Steps:
• Step 1: Calculate required torque (T = 9550 × P / n, where P = power in kW, n = speed in rpm).
• Step 2: Determine system pressure (reserve 20% margin).
• Step 3: Match port size (SAE B/C to pipe flange).
2. Installation Requirements:
• Horizontal Mounting: Motor axis horizontal deviation ≤0.5° to prevent plunger eccentric wear.
• Alignment Tolerance: Coupling misalignment ≤0.1 mm to avoid vibration.
• Oil Management: Use L-HM 46# anti-wear hydraulic oil, maintain 50–70°C oil temp.
3. Commissioning Tips:
• Jog 3 times before full-speed operation to confirm no abnormal noise.
• Replace oil and clean filters after50 hoursof initial operation.
