Root cause analysis:

Aging or wear of seals (such as O-rings and oil seals), decreased elasticity or surface damage after long-term operation.

Loose or improperly installed pipeline connections, such as loose joints or damaged threads.

Excessive filling of oil, exceeding the standard level, resulting in overflow.

Excessive internal clearance of hydraulic components (such as pumps and valves) can cause internal leakage.

Improvement suggestions:

Regularly replace seals: Check and replace aging seals every 6-12 months based on usage frequency and environmental conditions, with priority given to using high temperature resistant and wear-resistant fluororubber or polyurethane materials.

Strengthen pipeline maintenance: Check daily whether the pipeline connections are tight, use a torque wrench to tighten the joints according to the standard torque; Install anti loosening washers or clamps on high-frequency vibration parts.

Control oil level: Install a level gauge on the hydraulic oil tank to ensure that the oil level is within the calibration range (usually 80% -90% of the tank height) and avoid overfilling.

Internal leakage detection: Monitor the system pressure through a pressure tester. If the pressure drops too quickly (such as more than 10% within 10 minutes), disassemble the hydraulic components to check the clearance, and replace worn parts if necessary.

2、 Hydraulic clamping failure

Fault phenomenon: Hydraulic valve core or piston movement is obstructed, manifested as slow movement, jamming, or complete inability to move, accompanied by abnormal noise.

Root cause analysis:

Oil contamination, impurities (such as metal particles, dust) entering the gap between the valve core and valve body, causing increased friction or jamming.

The valve core undergoes deformation due to long-term compression, such as plastic deformation of the cone valve core due to high pressure, which cannot tightly fit with the valve seat.

Hydraulic oil viscosity is too high or temperature is too low, resulting in poor fluidity and insufficient lubrication.

Improvement suggestions:

Oil purification management:

Install high-precision oil filters (filtration accuracy ≤ 10 μ m) and regularly replace the filter element (every 3-6 months or according to the pressure gauge indication).

Before adding new oil, it needs to be filtered to avoid introducing impurities directly into the fuel tank.

Valve core protection and replacement:

Choose hard alloy valve cores (such as cobalt based alloys) or surface plated with hard chromium to improve wear resistance and deformation resistance.

Disassemble and inspect the valve core every 2 years, measure its straightness and roundness, and replace it if the deviation exceeds 0.02mm.

Optimize oil parameters:

Select hydraulic oil of appropriate viscosity grade based on the ambient temperature (such as HV low-temperature hydraulic oil in winter).

Install a heater in the hydraulic system to ensure that the oil temperature is ≥ 15 ℃ in low-temperature environments.

3、 Hydraulic impact fault

Fault phenomenon: The system pressure rises sharply (exceeding the rated pressure by more than 20%), accompanied by severe vibration and noise, which may cause pipeline rupture or component damage.

Root cause analysis:

Execution components (such as hydraulic cylinders) change direction too quickly, causing a sudden change in the direction of oil flow and pressure shock.

The closing speed of the hydraulic valve is too fast, such as the rapid return of the valve core when the electromagnetic directional valve is powered off, resulting in water hammer effect.

Unreasonable pipeline design, such as excessive bends, sudden changes in pipe diameter, or excessively long lengths, leads to increased resistance to oil flow.

Improvement suggestions:

Slow down the commutation speed:

Install a throttle valve or one-way throttle valve in front of the directional valve, and control the movement speed of the valve core by adjusting the flow rate.

Choose electromagnetic directional valves with buffering function (such as wet solenoid valves), and achieve soft landing through oil damping when the valve core returns.

Optimize pipeline layout:

Reduce the number of bends and use large radius bends (bending radius ≥ 3 times the pipe diameter) to reduce local resistance.

Install an accumulator in the long pipeline to absorb pressure fluctuations (such as using an airbag accumulator with an inflation pressure of 60% -80% of the system working pressure).

Install buffer device:

Install hydraulic buffers at the inlet and outlet of the hydraulic cylinder, and control the return oil speed through throttle holes to avoid piston impact on the end cap.

For high-frequency impact conditions, hydraulic cylinders with buffering function (such as composite cylinders with built-in buffering plugs) can be selected.

4、 System overheating fault

Fault phenomenon: The hydraulic oil temperature continues to rise (over 80 ℃), causing a decrease in oil viscosity, accelerated aging of seals, and even system leakage.

Root cause analysis:

The efficiency of hydraulic pumps decreases, such as excessive clearance between gear pump teeth or wear of blade pump blades, leading to increased internal leakage and energy conversion into thermal energy.

Cooling system failure, such as clogged radiator, insufficient fan speed, or low coolant flow.

Excessive system load or frequent start stop can cause the hydraulic pump to remain in a high-pressure state for a long time, resulting in increased heat generation.

Improvement suggestions:

Improve hydraulic pump efficiency:

Regularly check the volumetric efficiency of the pump (by measuring the output flow rate through a flow meter), and repair or replace it if the efficiency drops below 80%.

For gear pumps, check the tooth tip clearance every 2 years (standard value ≤ 0.1mm), and replace the gear or pump body if it exceeds the tolerance.

Enhanced cooling system:

Clean the dust on the surface of the radiator (once every 3 months) to ensure smooth ventilation; For air-cooled radiators, check the tension of the fan belt (deflection ≤ 10mm).

In high temperature environments (such as summer), switch to water-cooled radiators or increase coolant flow (by adjusting the opening of the bypass valve).

Optimize load management:

To avoid long-term idle operation of the hydraulic pump, control the start and stop of the pump through a pressure switch (such as setting a low pressure threshold of 3MPa).

For heavy-duty conditions, variable displacement pumps are used instead of quantitative pumps to reduce system pressure by adjusting displacement (such as using axial piston variable displacement pumps).

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment