Used Excavator Komatsu PC78US Gallery, Images, Pictures

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Used Excavator Komatsu PC78US Main Parts Pictures

The Komatsu PC78US is a compact hydraulic excavator designed for work in confined spaces, combining the power and functionality of a full-sized excavator with the compact design and maneuverability required for working in tighter environments. It is commonly used for urban construction, utility work, landscaping, and demolition tasks. Below are the main parts and components of the Komatsu PC78US excavator:

1. Engine

• Engine Type: The PC78US is powered by a Komatsu SAA4D95LE-5 turbocharged, 4-cylinder, direct-injection diesel engine.
• Rated Power: Approximately 55.4 kW (74.2 hp) at 2,200 rpm.
• Cooling System: Includes a radiator, oil cooler, and intercooler to ensure the engine operates at optimal temperatures and to prevent overheating.
• Fuel System: Uses a common rail fuel injection system that improves fuel efficiency, reduces emissions, and ensures smooth engine performance.

2. Hydraulic System

• The hydraulic system is a critical part of the PC78US, powering all of the excavator’s functions, including boom, arm, bucket, and swing.
• Main Hydraulic Pump: The PC78US uses a variable displacement hydraulic pump that provides the necessary flow and pressure to power digging, lifting, and swinging movements.
• Hydraulic Cylinders: These cylinders control the movement of the boom, arm (stick), and bucket, providing precise control for digging, lifting, and dumping materials.
• Pilot Control System: This system provides smooth and easy control of the machine’s functions by using pilot-operated hydraulic valves, which require less effort from the operator.
• Hydraulic Control Valve: Manages the flow of hydraulic fluid to different components such as cylinders and attachments to ensure smooth and efficient operation.

3. Undercarriage

• Track Frame: The undercarriage is compact yet durable, designed to provide maximum stability while maintaining a low center of gravity. This is critical for maintaining balance and safety, particularly when working on uneven terrain or slopes.
• Tracks: The PC78US is equipped with rubber tracks, which provide excellent ground contact while reducing ground pressure. These tracks are ideal for working on asphalt, turf, or delicate surfaces, and they help minimize damage to the environment.
• Track Rollers: These rollers support the weight of the machine and ensure smooth operation by reducing friction between the track and the ground.
• Idlers: Located at the front of the undercarriage, the idlers help guide the track system and maintain track tension.
• Sprockets: The sprockets engage with the track system to propel the excavator forward and backward.
• Track Shoes: These individual track pads provide ground contact, offering traction and stability as the excavator moves.

4. Upper Structure

• Cab: The operator’s compartment is designed for maximum comfort and visibility. The ergonomic design of the cab provides clear sightlines, reducing blind spots, while the controls are arranged to ensure ease of operation.
• Swing Bearing: The swing bearing allows the upper structure, including the boom, arm, and cab, to rotate 360 degrees, enabling continuous rotation for digging, lifting, and swinging.
• Counterweight: Located at the rear of the machine, the counterweight helps to maintain stability and balance, particularly when the machine is lifting heavy loads.
• Engine Hood: The protective cover for the engine and cooling components allows easy access for maintenance and inspection.

5. Boom, Arm (Stick), and Bucket

• Boom: The large vertical arm that provides the machine with its reach and height for digging and lifting tasks.
• Arm (Stick): The extendable arm that connects to the boom and provides the excavator with additional reach for digging and material handling.
• Bucket: The primary attachment used for digging, moving, and loading material. It is replaceable and can be customized based on the type of work (e.g., digging buckets, narrow buckets, and trenching buckets).
• Quick Coupler: The quick coupler system allows for fast and easy attachment changes, making the excavator more versatile and efficient on the job site.

6. Attachment System

• The PC78US can be fitted with a variety of attachments for different tasks, including:
  • Buckets (standard, narrow, trenching, and heavy-duty)
  • Hydraulic Hammers
  • Grapples
  • Augers
  • Rippers
• The quick coupler system allows for quick attachment changes, improving work efficiency and reducing downtime.

7. Cooling System

• Radiator: Removes excess heat from the engine coolant, ensuring that the engine remains within the optimal operating temperature range.
• Oil Cooler: Cools the hydraulic oil to prevent overheating during extended operations, preserving the longevity and efficiency of the hydraulic components.
• Coolant Reservoir: Stores coolant fluid to maintain a steady supply for the engine's cooling system.

8. Electrical System

• Alternator: Provides electrical power to charge the battery and supply energy to the electrical components of the excavator.
• Battery: Supplies the necessary power to start the engine and operate the electrical systems.
• Fuse Box and Wiring Harness: These manage the distribution of electrical power to the lights, sensors, displays, and other electrical components.
• Monitoring System: The PC78US may feature a monitoring system that tracks the health of various components (e.g., engine, hydraulics, fuel, and temperature) and alerts the operator to any potential issues.