Das Problem der Abweichung der Baggerfahrt

Excavators are essential machinery in construction and mining operations. When an excavator experiences traveling issues, it can significantly hinder productivity and efficiency. This blog will delve into the common causes of excavator traveling issues and provide detailed methods for troubleshooting and resolving these problems.

Common Causes of Excavator Traveling Issues

1. Contaminants in the Parking Brake Circuit’s Balance Valve

One frequent cause of traveling issues is the presence of contaminants in the parking brake circuit’s balance valve. When foreign particles block the small orifices in the balance valve, the parking brake cannot be disengaged, leading to traveling deviations. During operation, if hydraulic pressure cannot move the balance valve spool due to blockage, the hydraulic system cannot release the parking brake, causing the travel motor to malfunction.

Solution:

• Clean the Balance Valve: Ensure that the valve is free of contaminants.
• Prevent Contaminant Entry: During disassembly and reassembly, take precautions to avoid introducing dirt.
• Regelmäßige Wartung: Periodically replace hydraulic oil and filters according to specifications.

2. Damaged Center Swivel Joint Seals

The center swivel joint, comprising a housing and spindle, plays a crucial role in maintaining hydraulic fluid flow between the upper and lower parts of the excavator. If the hydraulic oil filter is not replaced timely, contaminants can damage the seals of the swivel joint. This can lead to uneven pressure distribution between the travel motors, causing traveling issues.

Solution:

• Replace Center Swivel Joint Seals: Ensure that the seals are intact and functioning correctly.
• Replace Hydraulic Oil and Filters: This prevents contaminants from entering the system.

3. Contaminants Blocking the Final Drive System‘s Balance Valve

Similar to the parking brake circuit issue, contaminants can also block the small orifices in the final drive system’s balance valve, preventing the release of the parking brake and causing traveling issues.

Solution:

• Clean the Balance Valve: Remove contaminants to ensure proper function.
• Prevent Contaminant Entry: Take care during maintenance to avoid introducing dirt into the system.

4. Leaking Travel Motor Relief Valve

A leaking relief valve in the travel motor can cause low system pressure, resulting in insufficient travel motor speed and traveling issues.

Solution:

• Replace Damaged Relief Valve: If the relief valve is damaged, replace it with a new one.
• Valve Testing: Swap the left and right travel motor relief valves to check if the issue reverses, confirming the valve is the problem.

5. Low Output Pressure of the Travel Proportional Valve

The travel proportional valve controls the speed and direction of the excavator’s travel motors based on joystick input. If the filter is clogged and the bypass valve opens, unfiltered hydraulic oil can cause the proportional valve to malfunction.

Solution:

• Check Proportional Valve Pressure: The ideal pressure should be around 3.3 MPa.
• Clean the Valve and Associated Lines: Ensure that the valve and hydraulic lines are free of contaminants.
• Replace Hydraulic Oil and Filters: Maintain clean hydraulic oil to prevent future issues.

6. Damaged Travel Suction Valve

The travel suction valve, located on the hydraulic cylinder and motor, helps protect the system from external shocks by relieving excessive pressure. If the valve is damaged, it can result in low oil pressure in the travel main valve, causing insufficient travel motor power.

Solution:

• Repair or Replace the Suction Valve: Ensure the valve is functioning correctly to maintain proper hydraulic pressure.

7. Malfunctioning Travel Main Valve Spool

A malfunctioning travel main valve spool, whether due to a weakened or broken spring or a jammed spool, can lead to reduced hydraulic pressure and traveling issues.

Solution:

• Measure the Hydraulic Pressure: The pressure in the travel main valve circuit should be about 32.5 MPa.
• Repair or Replace the Main Valve: If the main valve is damaged, it should be repaired or replaced.

Troubleshooting Steps for Excavator Traveling Issues

Step 1: Initial Diagnosis

Visuelle Inspektion: Start with a thorough visual inspection of the excavator. This step is crucial because many issues can be identified through a simple visual check. Look for any signs of wear, cracks, or leaks in the hydraulic hoses, connectors, and cylinders. Hydraulic oil leaks not only lead to a drop in hydraulic system pressure but also cause environmental contamination and potential equipment damage. Additionally, check the tracks and drive wheels for any visible wear or damage. Ensure that the track tension is appropriate, as tracks that are too loose or too tight can affect the excavator’s traveling performance.

Operational Test: After the visual inspection, start the excavator and observe its actual operation. By operating the excavator, pay attention to which side of the tracks is lagging or malfunctioning. Specifically, you can determine which track has issues by performing basic operations such as moving forward, backward, turning left, and turning right. If one side of the track is sluggish or completely unresponsive, it may indicate problems in the hydraulic system or mechanical components.

Step 2: Hydraulisches System Inspektion

Check Hydraulic Oil and Filters: The normal operation of the hydraulic system depends on clean hydraulic oil and effective filters. First, check the hydraulic oil level to ensure it is within the recommended range; if it is low, add the appropriate type of hydraulic oil. Next, examine the color and condition of the hydraulic oil; it should be clear. If the oil has changed color or contains contaminants, it needs to be replaced. Finally, check the hydraulic filters to ensure they are not clogged. If the filters are blocked, replace them to ensure smooth oil flow.

Inspect Valves: The balance valve, proportional valve, and relief valve are critical to the proper functioning of the hydraulic system. First, inspect the balance valve to ensure it is working correctly, as a faulty balance valve can cause system imbalances, affecting the excavator’s traveling performance. Next, check the proportional valve, as a malfunctioning proportional valve can lead to uneven hydraulic oil flow, impacting the driving force of the tracks. Finally, inspect the relief valve, as a faulty relief valve can cause abnormal system pressure, affecting the overall operation of the hydraulic system.

Step 3: Component Testing

Pressure Testing: To further pinpoint the issue, conduct pressure testing on different parts of the hydraulic system. Use a pressure gauge to measure the pressure in the hydraulic system and compare the test results with the manufacturer’s standard pressure values to identify any discrepancies. Pressure testing helps determine if there are faults in the hydraulic pump, hydraulic motor, or hydraulic lines.

Valve Swapping: To identify if the valves are faulty, try swapping the valves between the left and right sides. If the problem moves to the other side along with the valve, it indicates a faulty valve that needs replacement or repair. If the problem does not move with the valve, further inspection of other hydraulic system components or mechanical parts is necessary.

Step 4: Cleaning and Replacement

Clean Contaminated Parts: If any parts are found to be contaminated during the previous checks, they need to be thoroughly cleaned. Use professional cleaning agents and tools to remove contaminants from valves, pipelines, and other hydraulic system components, ensuring smooth hydraulic oil flow.

Replace Damaged Components: For components that are damaged or severely worn, replacement is necessary. When replacing hydraulic seals, valves, or other damaged parts, ensure you use original or qualified substitutes to guarantee the system’s proper functioning. Avoid using low-quality parts to prevent further damage.

Step 5: Reassembly and Testing

Reassemble Components: After cleaning and replacement, carefully reassemble all parts. Make sure no new contaminants are introduced during reassembly, and secure all connections tightly to prevent looseness and leaks.

Operational Test: Finally, start the excavator and perform a comprehensive operational test. By moving forward, backward, turning left, and turning right, confirm the issue has been resolved. If the excavator travels normally, the problem has been fixed. If the issue persists, further inspection of the hydraulic system or other mechanical components may be required.

Schlussfolgerung

Traveling issues in excavators can arise from a variety of causes, including contaminants in the hydraulic system, damaged seals, and malfunctioning valves. By understanding these common issues and following a systematic troubleshooting approach, operators can effectively diagnose and resolve traveling problems, ensuring that their excavators operate smoothly and efficiently.

Regular maintenance, including timely replacement of hydraulic oil and filters, is crucial in preventing many of these issues. By staying vigilant and proactive, operators can minimize downtime and keep their excavators running at peak performance.

FRAGEN UND ANTWORTEN

Question 1: What are the common symptoms of a failing hydraulic pump in an excavator?

Answer: Common symptoms of a failing Hydraulikpumpe include:

• Reduced hydraulic power: The excavator may struggle to lift loads or move as efficiently as it used to.
• Unusual noises: A failing pump might produce whining, grinding, or knocking noises.
• Überhitzung: The hydraulic system may overheat due to excessive friction or lack of proper lubrication.
• Lecks: Hydraulic fluid leaks around the pump or other system components.
• Erratic movements: The excavator may exhibit jerky or inconsistent movements due to irregular hydraulic pressure.

Question 2: How can you diagnose a hydraulic pump issue in an excavator?

Answer: To diagnose a hydraulic pump issue, you can:

• Check hydraulic fluid levels and condition: Ensure the fluid is at the correct level and not contaminated.
• Inspect for leaks: Look for any visible signs of hydraulic fluid leaks around the pump and hydraulic lines.
• Listen for unusual noises: Start the excavator and listen for any abnormal sounds coming from the hydraulic pump.
• Conduct a pressure test: Use a pressure gauge to measure the hydraulic pressure and compare it to the manufacturer’s specifications.
• Examine pump performance: Observe the excavator’s operations for any signs of reduced power or erratic movements.

Question 3: What are the potential causes of hydraulic pump failure in an excavator?

Answer: Potential causes of hydraulic pump failure include:

• Contaminated hydraulic fluid: Dirt, debris, or water in the hydraulic fluid can cause wear and damage to the pump.
• Lack of maintenance: Neglecting regular maintenance, such as changing filters and hydraulic fluid, can lead to pump failure.
• Überhitzung: Excessive heat can cause the pump components to expand and seize.
• Improper fluid levels: Running the hydraulic system with low or excessive fluid levels can damage the pump.
• Wear and tear: Normal wear and tear over time can lead to pump component failure.

Question 4: How can you prevent hydraulic pump failure in an excavator?

Answer: To prevent hydraulic pump failure, you can:

• Perform regular maintenance: Regularly check and change hydraulic fluid and filters according to the manufacturer’s recommendations.
• Monitor fluid levels: Ensure hydraulic fluid levels are within the recommended range.
• Use quality hydraulic fluid: Use the appropriate type and quality of hydraulic fluid specified by the manufacturer.
• Inspect for leaks: Regularly check for and repair any hydraulic fluid leaks.
• Avoid excessive loads: Operate the excavator within its designed load limits to prevent overworking the hydraulic pump.

Question 5: What should you do if you suspect a hydraulic pump failure in your excavator?

Answer: If you suspect a hydraulic pump failure, you should:

• Stop the excavator: Immediately stop using the excavator to prevent further damage.
• Perform a thorough inspection: Check for any visible signs of damage, leaks, or contamination in the hydraulic system.
• Conduct diagnostic tests: Perform pressure tests and listen for unusual noises to identify the issue.
• Consult the manual: Refer to the excavator’s maintenance manual for troubleshooting steps and specifications.
• Seek professional help: If you are unable to identify or fix the issue, contact a professional technician to inspect and repair the hydraulic pump.