205-70-73130 Product: Komatsu PC200-6 bucket H connecting rod / I-beam frame
Basic Introduction | Application Devices
Compatible model
Part 205-70-73130 is specifically designed for the Komatsu PC200-6 excavator. It belongs to the core load-bearing structure component of the bucket mechanism (commonly known as the H-link, the I-beam frame).
Installation location: At the front end of the excavator's small arm and above the bucket, connecting the bucket oil cylinder, the small arm, and the bucket. Function: Transmits the excavation thrust and pull force, transferring the oil cylinder power to the bucket to complete excavation, material removal, and lifting actions. It is a key component in the bucket assembly that withstands alternating impact loads.
Applicable scenarios (application conditions)
1. Landscaping projects: Site leveling, foundation pit excavation, river dredging
2. Mining and quarrying: Rock stripping, stone loading (heavy impact conditions)
3. Infrastructure construction: Road construction, bridge foundation excavation
4. Demolition projects: Construction waste crushing, demolition operations
Product structure and industry knowledge
1. Material: High alloy cast steel, cast as one piece, not a welded steel plate. The cast part has stronger impact toughness and is suitable for continuous vibration operation of excavators; welded connecting rods are more prone to cracking under heavy load.
2. Process: Quenching and tempering (quenching + tempering), enhancing overall strength and reducing brittleness; CNC precision boring of holes to ensure the clearance between the pin shaft, bushing and the connecting rod.
3. Common failure forms (frequently consulted by customers)
Cracking of the connecting rod body: Long-term overloading, digging hard rocks, impact load exceeding the material's endurance limit
Enlarged inner hole and loss of roundness: The bushing wears out but is not replaced in time, and the pin shaft directly rubs against the connecting rod hole
Deformation and twisting: Forced levering of huge rocks, rough operation, causing permanent plastic deformation
Rusting: Long-term outdoor and maritime storage, lack of rust protection
Industry knowledge: The H connecting rod itself rarely wears out alone; most damage origins are the failure of the bushing and pin shaft. Many customers only replace the connecting rod but not the bushing, and the new connecting rod soon wears out again.
Usage Guidelines
1. Strictly prohibit rough excavation: Do not use the side of the bucket to forcefully pry rocks or heavy objects. The lateral impact force is very likely to cause the H-link rod to break or deform; the force applied during excavation should be as much as possible to be distributed on the front side of the bucket.
2. Do not operate beyond the rated load capacity: The PC200-6 has a rated excavation load. Long-term operation beyond the load limit will accelerate the fatigue of the link rod and shorten its service life.
3. Prohibit continuing construction when the gap between the link rod holes is too large: If the pin bushing shakes significantly, the machine must be stopped for maintenance. After the gap increases, the impact load will be multiplied, and the link rod holes will be rapidly worn out.
4. Assembly requirements: When installing, the pin and bushing must be replaced together; the surface of the pin should be coated with lubricating grease to ensure coaxiality. Do not force assembly by hammering to avoid damage to the hole positions.
5. Working environment: When operating in a strongly corrosive site (salt-alkali land, chemical waste soil), it will accelerate rusting. Frequent inspections are required.
Maintenance and Repair Manual
Daily Maintenance (Daily Inspection)
1. Lubrication: Add high-temperature resistant lithium-based lubricating grease to the pin shaft lubrication nozzle every day to ensure an oil film is formed between the pin shaft and the bushing, reducing friction. Lack of lubrication is the primary cause of rapid wear of the bushing and connecting rod hole.
2. Visual Inspection: Daily check the main body of the H connecting rod, checking for cracks, chips, and deformation; pay special attention to the casting fillets and the surrounding areas of the holes (the most prone to cracking locations).
3. Clearance Check: Observe the wobble of the pin shaft. Obvious wobble indicates wear of the bushing and should stop the machine for replacement immediately.
Regular Maintenance (200 hours / 500-hour maintenance cycle)
1. Every 200 hours: Carefully inspect the wear condition of the inner wall of the connecting rod hole and measure the diameter. If the diameter exceeds the standard, the connecting rod must be repaired or replaced.
2. Every 500 hours: Overall flaw detection (if possible), check for subtle hidden cracks; inspect the paint anti-rust layer, reapply anti-rust paint at the areas where the paint has peeled off to prevent rust and corrosion.
3. Storage Maintenance: For equipment that is idle for a long time, clean the dirt and debris on the surface of the connecting rod, repaint, apply thick lubricating grease to the pin shaft area; for outdoor storage, it is recommended to cover it to prevent rain.
