The role of hydraulic oil filtration system

The hydraulic oil filtration system is a core component of the hydraulic system. Its main function is to maintain the cleanliness of the hydraulic oil, thereby ensuring the hydraulic system's stable operation, extending the equipment's life and improving efficiency. The following is a detailed description of its role from multiple dimensions:

Core role: remove pollutants

Hydraulic oil will be mixed with a variety of pollutants during use, such as:

- Solid particles: metal debris, dust, rubber seal wear particles.

- Water: condensed or external water (causing oil emulsification and oxidation).

- Air: bubbles mixed in the oil (causing cavitation and reducing oil stiffness).

- Gel and sludge: products of oil oxidation and deterioration.

The filtration system intercepts these pollutants through filter elements (such as paper, metal mesh, polymer materials) to prevent them from entering precision components such as hydraulic pumps, valves, and cylinders.

Protect hydraulic components

- Reduce wear

Particles can scratch the pump, valve core, and cylinder body wall, causing leakage or valve jamming. For example, particles >10μm can cause servo valves to clog.

Example: If the valve plate of a plunger pump is worn due to contamination, it will cause pressure fluctuations or even failure.

- Preventing sticking

Contaminants can clog the tiny oil passages or throttle ports of hydraulic valves, causing slow movement or failure (such as the slow movement of excavators).

Maintaining oil performance

- Delaying oil oxidation

Water and metal particles will catalyze oil oxidation to generate acidic substances and colloids. The filtration system removes these catalysts and extends the service life of the oil.

- Maintaining viscosity stability

Contaminants (such as colloids) will change the fluidity of the oil. After filtering, system overheating or insufficient power caused by abnormal viscosity can be avoided.

Improving system reliability

- Reducing failure rate

According to statistics, more than 70% of hydraulic system failures are caused by oil contamination. Efficient filtration can significantly reduce the frequency of downtime and maintenance.

- Adapt to high-precision requirements

Precision machine tools, aviation hydraulic systems, etc., require oil cleanliness to reach ISO 15/13/10 level (NAS level 6 or below), and the filtration system is the key guarantee.

Economic benefits

- Extend the oil change cycle

Clean oil oxidizes slowly, which can reduce the frequency of oil changes and save costs (the cost of industrial hydraulic oil replacement can reach thousands of yuan per time).

- Reduce component replacement

Avoid damage to pumps and valves caused by pollution and reduce spare parts procurement costs.

Environmental protection and safety

- Reduce waste oil emissions

Extending the life of the oil means less waste oil treatment and reduced environmental pollution.

- Prevent accidents caused by oil deterioration

Contaminated oil may cause a sudden ｄｒｏｐ in system pressure or valve failure, causing equipment to lose control (such as an accidental ｄｒｏｐ of an engineering robot arm).

Classification and selection of filtration systems

Based on the installation location and function, common types include:

| Type | Location | Features |

|----------------|--------------------|--------------------------------------|

| Suction filter | Pump suction port | Coarse filtration (80-150μm), protect pump inlet |

| Pressure filter | Pump outlet or before valve group | High precision (5-25μm), protect precision components |

| Return filter | Return oil pipeline | Intercept wear particles in system return oil |

| Offline circulation filtration | Independent bypass | 24-hour circulation filtration, suitable for systems with high cleanliness requirements |

Maintenance recommendations

1. Regularly ｒｅｐｌａｃｅ the filter element

ｒｅｐｌａｃｅ according to the pressure difference alarm or period (such as every 2000 hours) to avoid clogging of the filter element and causing the bypass valve to open (pollutants directly enter the system).

2. Monitor contamination

Use a particle counter to regularly detect oil cleanliness (such as ISO 4406 standard).

3. Control the source of pollution

- Use filtering equipment when refueling.

- Keep the oil tank sealed to prevent dust and moisture from entering.

The hydraulic oil filtration system is like the "kidney" of the hydraulic system. It continuously removes pollutants to ensure the efficient, stable and long-life operation of the system. Reasonable design of filtration solutions (such as multi-stage filtration, precision matching) and strict maintenance are the key to its role.