What are the common faults of single-tire compartment semi-trailers?

Single-tire compartment semi-trailers are gradually becoming popular in long-distance logistics due to their lightweight design and flexible loading capacity. However, its single-tire structure and cage characteristics also bring specific fault risks, which require targeted inspection and maintenance from the four core modules of the braking system, axle assembly, suspension structure and electrical system.

I. Braking System: Airway Failure and Drag Brake Risk

Single-tire vehicles have higher requirements for braking response accuracy, and airway problems are prone to cause safety hazards. Common faults include:

1. Insufficient air pressure or air leakage: If the air pressure remains below 0.7MPa for a long time, it is necessary to check the air supply capacity of the tractor, the sealing of the handshake connection, and whether the pipeline joints are loose. For instance, a vehicle of a certain logistics company was dragged to the brakes due to a leak in the emergency relay valve. The problem was repaired after applying soapy water to locate the source of the leak and replacing the valve body.

2. Dragging brake or locking up: If there is no dragging brake when reversing but the movement is abnormal, it may be due to the failure of the reset spring or the wear of the camshaft copper sleeve. After parking, if the braking cannot be released, it is necessary to check the air pressure of the manual control valve, the connection of the ABS helical line and mechanical faults of the axle. A certain fleet once experienced a blockage at the main valve air intake due to improper modification of the airway. Eventually, the problem was solved by restoring the original factory design.

Ii. Axle Assembly: Increased load and wear on a single tire

The pressure carried by a single tire is concentrated, which imposes strict requirements on the reliability of the axle system.

1. Uneven tire wear or wobbling: The main causes are uneven tire pressure, deformed rims or worn axle bearings. Due to the failure to adjust the tire pressure as required, the single-tire wear rate of a certain enterprise's vehicle was 40% higher than that of a two-tire model. After the adjustment, the tire life was extended by 30%.

2. Hub overheating: Poor return of brake shoes or overly tight bearing lock nuts can cause high temperatures. For instance, a long-distance transport vehicle nearly caused a fire due to a broken brake shoe spring, with the hub temperature reaching 120℃.

3. Axle bending or bearing sintering: Overloading or long-term eccentric loading may cause axle deformation. It is necessary to regularly check the wheelbase error and the condition of the connecting rod rubber sleeve. A certain fleet has reduced the axle failure rate by 50% by installing an axle load monitoring system.

Iii. Suspension Structure: A Balance between Lightweight and Load-bearing Capacity

1. Single-tire models are equipped with high-strength lightweight suspensions, but they are prone to malfunction due to overloading or improper maintenance.

Leaf spring breakage: Overloading or loosening of U-bolts can cause the spring to break. Due to long-term over-limit transportation, the lifespan of the leaf springs in a certain enterprise's vehicles was shortened by 60%. After switching to reinforced springs, the design standard was restored.

2. Abnormal suspension noise: Wear of the copper sleeve of the balance shaft or damage to the tensile rubber can cause noise. Regular lubrication of the balance beam joint and replacement of worn parts can effectively solve the problem.

Iv. Electrical System: Circuit Hazards and Functional Failures

The structure of the warehouse fence needs to be opened and closed frequently, which can easily cause the electrical circuits to loosen.

1. If the car lights do not work or the signal is abnormal: A damaged bulb, a loose plug or an oxidized seven-core power connector are common causes. A certain fleet reduced the electrical failure rate by 75% by installing waterproof connectors.

2. False alarm of ABS system: Dirty sensors or short circuits in the circuit will trigger the fault light. Regular cleaning of sensors and checking of circuit insulation can prevent false alarms.

V. Structural Characteristic Associated Faults: Synergistic Risks between sidewalls and Single Tires

1. Overturning caused by uneven loading: Single-tire models have relatively weak anti-roll capabilities and must be loaded strictly according to the axle load distribution. A certain enterprise has reduced the rate of rollover accidents by 80% by installing a dynamic weighing system.

2. Malfunction of the cage lock: Deformation of the main beam or rusting of the lock top can affect the fixation of the container. Regular inspection of the lubrication status of the lock and the straightness of the beam can prevent risks.

Conclusion

The fault management of single-tire compartment semi-trailers needs to take into account both lightweight design and safety redundancy. By establishing a "preventive maintenance + intelligent monitoring" system, such as installing tire pressure monitoring, axle load sensors and airway drying devices, the vehicle availability rate can be significantly improved. In the future, with the application of carbon fiber composite material axles and self-healing tire technology, the reliability of single-tire vehicles will be further enhanced, providing more efficient solutions for long-distance logistics.