Kobelco SK45SR Mini Excavator Overview

[MikePhua]

Machine Profile
The Kobelco SK45SR is a compact mini excavator well-regarded for its combination of power, maneuverability, and advanced technology. It is designed with a short-tail swing to maximize work efficiency in confined spaces without sacrificing performance.
Engine and Power

• Equipped with a Yanmar 4TNV88-B water-cooled, 4-cylinder, direct injection diesel engine.
  
• Rated power output is approximately 29.6 kW (about 40 hp) at 2400 rpm.
  
• Engine provides a maximum torque rating of about 131.8 to 133.3 Nm at 1560 rpm.
  
• The fuel tank has a capacity of 75 liters, supporting extended operational times.
  

Hydraulic System

• Features two variable displacement pumps plus one gear pump.
  
• Maximum discharge flow rates: Two pumps deliver approximately 49.9 L/min each, and the gear pump delivers about 33.8 L/min.
  
• Relief valve setting is at 23 MPa providing safe hydraulic pressure limits.
  
• Hydraulic oil tank capacity ranges between 27.9 liters to 57.7 liters for system and reserve.
  

Travel and Mobility

• Uses dual axial-piston, two-step travel motors for efficient movement.
  
• Travel speed varies by track type:
  • Rubber tracks: 4.0 km/h high / 2.3 km/h low
    
  • Steel tracks: 3.7 km/h high / 2.1 km/h low
    
• Oil disc brakes are integrated for secure parking.
  

Dimensions and Weight

• Overall width: 1960 mm (approximately 6.4 feet)
  
• Dozer blade width x height: 1960 mm x 345 mm
  
• Machine mass ranges from 4450 to 4700 kg (approx 9800 to 10360 lbs), depending on track type and configuration.
  
• Ground pressure varies slightly between rubber and steel tracks but remains low enough to minimize surface damage.
  

Performance

• Bucket capacities are offered in multiple sizes, from 0.086 m³ (700 mm wide) to 0.21 m³ (750 mm wide).
  
• The arm and boom have large cross-sectional segments reinforcing attachment strength.
  
• The bucket features cast-iron idler links and the dozer has box construction supports for added durability.
  
• Swing speed is approximately 8.8 rpm driven by axial piston motors.
  

Operator Comfort and Safety

• Run with a rectangular cab providing spacious operation and an unobstructed view.
  
• The integrated noise and dust reduction (iNDr) cooling system ensures quieter operation and easier maintenance.
  
• The machine is designed to be about 9 dB quieter than previous models, enhancing operator comfort.
  
• Safety features include standard multi-color displays, rearview mirrors, arm and bucket cylinder covers, and lighting for canopy operation.
  

Additional Features

• One-touch deceleration allows easy switching to idle to save fuel.
  
• Energy Conservation Mode reduces fuel consumption by about 23% in “S” mode compared to “H” mode.
  
• Standard equipment includes a 2-way dozer blade with float, designed specifically so earth falls forward instead of behind the blade.
  

Terminology

• Variable Displacement Pump: Hydraulic pump whose output volume changes depending on demand for precise control.
  
• Axial-Piston Motor: Type of hydraulic motor used for efficient rotation and torque conversion.
  
• iNDr Cooling System: Integrated noise and dust reduction cooling system enhancing machine reliability and operator comfort.
  
• One-Touch Deceleration: Feature allowing quick transition to idle speed to reduce fuel use.
  
• Short Tail Swing: Configuration reducing rear overhang to improve maneuverability.
  

Summary
The Kobelco SK45SR mini excavator combines compact size and advanced hydraulics to deliver powerful performance suitable for tight and demanding job sites. Its efficient engine, variable displacement hydraulics, and innovative cooling system offer operators comfort and productivity with reduced noise and fuel consumption. The machine’s durability and thoughtful design make it a competitive choice for excavation and multilayered construction work.