As a core component ensuring user safety, wheelchair brakes require comprehensive assessment of wear and tear after long-term use, taking into account structural characteristics and usage scenarios. Wear is primarily concentrated on brake pads, brake cables, brake drums, and connecting parts, directly impacting braking performance and operational stability. Accurate detection necessitates multi-dimensional observation and testing, while repair requires selecting a targeted solution based on the type of damage, while also considering material compatibility and structural strength.
Wear inspection of wheelchair brake pads requires a combination of visual observation and thickness measurement. Normally used brake pads should have a smooth surface. If obvious grooves, cracks, or a reduction in thickness to less than two-thirds of their original size appear, replacement is necessary. During inspection, the brake pads can be removed, and the thickness of key areas measured with calipers, while simultaneously checking the uniformity of the contact area with the brake drum. Uneven wear on the contact surface may indicate improper brake pad installation or brake drum deformation, requiring further investigation. When repairing, brake pads made of the same material as the original manufacturer should be used to avoid braking vibration or noise caused by differences in hardness or coefficient of friction.
Damage inspection of brake cables requires attention to elasticity and connection condition. After prolonged use, brake cables may experience metal fatigue due to repeated stretching, resulting in weakened elasticity or breakage. During inspection, manually operate the brake lever to observe whether the brake cable rebounds smoothly. If the rebound is slow or there is jamming, check if the outer sheath of the brake cable is damaged and if the internal wires are rusted or broken. Repairing this requires replacing the entire brake cable, ensuring the new cable is the same length as the original to avoid excessive or insufficient brake lever travel due to length discrepancies, which would affect operating comfort.
Wear inspection of brake drums requires a combination of dimensional measurement and surface observation. The inner wall of the wheelchair brake drum should be smooth and free of scratches. Deep grooves or localized bulges may indicate hard particles embedded in the brake pads or that the brake drum material is too soft. During inspection, use an inside micrometer to measure the inner diameter of the brake drum. If the size exceeds the tolerance range, the brake drum must be replaced. During repair, pay attention to the coaxiality of the brake drum and wheel to prevent wheelchair deviation during braking due to installation misalignment. For aluminum alloy brake drums, their heat dissipation performance must also be checked. If the heat dissipation holes are clogged due to wear, they need to be cleaned or replaced.
Damage inspection of connecting components should focus on loosening and deformation. Bolts, nuts, and connecting rods in the braking system are subjected to alternating loads over a long period, which may cause loosening or plastic deformation. During inspection, the connecting components can be manually cranked to observe for obvious gaps or abnormal noises. If any are found, the bolts need to be tightened or the deformed components replaced. When repairing, fasteners of the same specifications as the original manufacturer should be used, and thread-locking agent should be applied to prevent loosening again due to vibration. For plastic connecting components, such as the brake handle housing, if cracks or breaks appear, the parts need to be replaced to avoid brake failure due to insufficient strength.
Inspection of hydraulic braking systems should focus on the fluid condition and sealing. If the wheelchair uses hydraulic brakes, the cleanliness of the brake fluid needs to be checked regularly. Contaminated or insufficient fluid can lead to sluggish braking response or failure. During inspection, the brake fluid reservoir level can be observed. If it is below the minimum mark, the same type of brake fluid needs to be added, and the oil lines and joints should be checked for leaks. During repair, aged or damaged hydraulic hoses must be replaced, and the joints must be properly sealed to prevent air from entering the hydraulic system and affecting braking performance.
Post-repair verification requires actual road testing. After reinstalling the repaired brake system, the braking effect must be tested under different inclines and road conditions to observe whether the wheelchair can stop smoothly without abnormal noise. If the braking distance is significantly longer or uneven braking occurs, the brake system must be readjusted to ensure it meets safety standards.
