Overview

The document provides detailed technical specifications, installation guidelines, operational parameters, and maintenance recommendations for the Sunfab SCM series axial piston hydraulic motors, covering models SCM 012 to SCM 130.

1. Technical Specifications

• Displacement Range: 12 to 130 cm³ per revolution.
• Maximum Operating Pressure: 400 bar service pressure; intermittent pressure up to 350 bar.
• Speed Limits: Maximum continuous speeds vary by model, with intermittent speeds higher; minimum speeds also specified.
• Power Output: Maximum intermittent and continuous power ratings provided, based on speed and pressure.
• Starting Torque: High starting torque characteristic due to spherical pistons and bent axis design.
• Mass and Inertia: Moment of inertia and mass values given for each model.

2. Design and Construction

The SCM motors are axial piston type with bent axis and spherical pistons, resulting in a compact design with few moving parts, high starting torque, and excellent reliability. The shaft is supported by double tapered roller bearings allowing high load capacity and speed.

3. Performance Data

Tables provide detailed data on displacement, pressure, speed, power, torque, and mass for each motor size. Power ratings distinguish between continuous and intermittent operation, with intermittent defined as maximum 6 seconds per minute (e.g., peak load during acceleration or unloading).

4. Operating Conditions and Limits

• Temperature Limits: Maximum oil temperature in the drain line is 75°C with nitrile seals and 90°C with Viton seals; system temperature should not exceed 60°C.
• Pressure Limits: Maximum service pressure 400 bar; intermittent pressure up to 350 bar.
• Oil Viscosity: Minimum 10 cSt for lubrication safety; ideal range 20-40 cSt.
• Filtration: Cleanliness level per ISO 4406 code 16/13 recommended.
• Oil Flow Velocity: Recommended maximum velocity in pressure lines is 7 m/s.

5. Installation Guidelines

• The motor housing must be filled at least 50% with oil before startup.
• The drain line must be connected to the highest purge port and routed back to the oil reservoir below oil level.
• Drainage can be via a drain valve or direct return line; a backpressure valve may be required if return pressure is too low.
• Recommended flow rates and continuous speeds are specified for different motor sizes to ensure proper cooling and lubrication.

6. Shaft and Mounting Details

• Shafts are available in splined or keyed versions according to DIN standards.
• Dimensions and tolerances for shafts and mounting holes are provided, including thread sizes and keyway details.
• Mounting flange and bolt patterns are standardized for each motor size.

7. Seal Selection

• Seal choice depends on hydraulic pressure and drain oil temperature.
• Nitrile seals suitable up to 75°C; Viton seals recommended for higher temperatures up to 90°C.

8. Bearing Load and Longevity

• The motor’s bearing life is influenced by operating speed, pressure, oil viscosity, filtration, and external radial loads on the shaft.
• Proper load direction and magnitude are critical for bearing longevity.
• For specific application longevity data, contact Sunfab Hydraulics.

9. Safety and Operational Recommendations

• Do not touch pressurized lines during operation.
• Beware of moving parts and high surface temperatures on motor and pipes.

10. Useful Formulas

The document includes formulas for calculating required flow rate, speed, torque, and power based on displacement, pressure difference, and efficiencies (volumetric, hydro-mechanical, and total).

Summary

The Sunfab SCM series hydraulic motors are robust, compact axial piston motors designed for mobile hydraulic systems with high reliability and performance. The document provides comprehensive data on mechanical dimensions, operating parameters, installation, and maintenance to ensure optimal use and longevity. Key considerations include adherence to pressure and temperature limits, proper oil viscosity and cleanliness, correct seal selection, and careful installation of drain and return lines.