Milling machine power system fault diagnosis and repair guide

1. Introduction to milling machine power system

     Introduction au système d'alimentation de la fraiseuse**

     Introducción al sistema de potencia de la fresadora** 

The power system of the milling machine is the core of its efficient operation. It is mainly composed of a diesel engine, a hydraulic transmission device, a power distribution module, etc., and realizes functions such as milling, traveling, and feeding through precise coordination.

Its core working principle can be summarized as follows:
- **Power transmission path**: The diesel engine drives the hydraulic pump, which converts mechanical energy into hydraulic energy, and drives the milling rotor, travel device and auxiliary system through the hydraulic motor and hydraulic cylinder.
- **Key component functions**:
- **Diesel engine**: Provides continuous and stable power output, with a common power range of 100-600kW to meet different working conditions.
- **Hydraulic system**: It adopts a multi-pump independent closed design to ensure that the high-speed rotation of the milling rotor (up to 2000rpm) does not interfere with the movement of the whole machine, and has high reliability.
- **Transmission device**: Through the gear box and chain transmission, the power is accurately distributed to the milling rotor and the travel wheel. Some models are equipped with an automatic leveling device to ensure the stability of the milling depth.
2. Common power system failures and maintenance solutions**

     Pannes courantes du système électrique et solutions de maintenance**

     Fallas comunes del sistema eléctrico y soluciones de mantenimiento**
During long-term high-load operation, the power system of the milling machine is prone to failure due to wear, improper operation or environmental factors.
The following are typical problems and solutions:
**2.1 Difficulty starting the engine or insufficient power**Dificultad para arrancar el motor o potencia insuficiente
- **Possible reasons**:
- The fuel filter is clogged or the fuel line is filled with air (common in low-quality diesel environments).
- Turbocharger failure causing insufficient air intake.
- Failure of electronic control system sensors (such as water temperature and oil pressure sensors) causes protective shutdown.
- **Maintenance suggestions**:
- Replace fuel filters regularly and use clean diesel that meets the standards.
- Check the sealing and blade condition of the turbocharger and clean the carbon deposits.
- Read the fault code through the diagnostic tool, replace the damaged sensor or repair the circuit.

**2.2 Abnormal hydraulic system pressure**Presión anormal del sistema hidráulico
- **Failure manifestation**:
- The milling rotor speed is unstable or weak.
- The whole machine moves slowly or even stops moving.
- **Diagnosis and Repair**:
- **Pressure test**: Use a hydraulic gauge to detect the main pump output pressure. If it is lower than the rated value (usually 20-35MPa), check the hydraulic pump for wear or overflow valve sticking.
- **Oil management**: Hydraulic oil contamination is a common cause. Replace the filter element regularly and check the oil cleanliness (NAS level 9 or below is preferred).
- **Replacement of seals**: Excessive oil temperature (over 80°C) may cause seal failure, and the cooler efficiency and pipeline leaks need to be checked.
**2.3 Abnormal vibration or noise of transmission parts**Vibración o ruido anormal en las piezas de la transmisión
- **Typical scenario**:
- During milling operation, the machine body vibrates violently, accompanied by metal friction sounds.
- The chain slips or the gearbox overheats while traveling.
- **Solution**:
- **Milling rotor inspection**: If the cutter head is unevenly worn or the cutter seat is loose, it needs to be retightened and the damaged blade replaced (it is recommended to check the condition of the cutter head every 50 hours).
- **Chain/gear maintenance**: adjust the chain tension and add the specified type of lubricant to the gearbox to avoid tooth surface wear due to poor lubrication.
**2.4 Electrical control system failure**Falla del sistema de control eléctrico
- **FAQ**:
- The control panel does not respond or gives false alarms (e.g. “overload protection” is frequently triggered).
- Loss of sensor signal causes the automatic leveling function to fail.
- **Maintenance Strategy**:
- **Power supply detection**: Check the battery voltage (24V±10%) and line connection to avoid false connection or oxidation.
- **Module replacement method**: Quickly locate the source of the fault by replacing the PLC module or drive controller.

**3. Preventive maintenance - the key to extending the life of the power system**

Maintenance préventive - la clé pour prolonger la durée de vie du système électrique*

Mantenimiento preventivo: la clave para prolongar la vida útil del sistema eléctrico*
- **Daily Check**: Oil level, coolant, belt tightness and visual leaks.
- **Quarterly maintenance**: replace hydraulic oil filter, clean radiator, calibrate sensor.
- **Annual overhaul**: comprehensive disassembly and inspection of hydraulic pump, engine cylinder and transmission gearbox, and replacement of worn parts.

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Through systematic fault diagnosis and standardized maintenance, the service life of the milling machine can be significantly extended, work efficiency can be improved and the risk of downtime can be reduced.

Grâce à un diagnostic systématique des pannes et à une maintenance standardisée, la durée de vie de la fraiseuse peut être considérablement prolongée, l'efficacité du travail peut être améliorée et le risque de temps d'arrêt peut être réduit.

Mediante un diagnóstico sistemático de fallas y un mantenimiento estandarizado, se puede extender significativamente la vida útil de la fresadora, se puede mejorar la eficiencia del trabajo y se puede reducir el riesgo de tiempo de inactividad.