QW250-40 Pneumatic Drum Brake for Conveyor & Crane

Product Overview

QW250-40 pneumatic drum brake is a high-reliability air-driven industrial braking device designed with a classic spring braking, pneumatic release fail-safe structure. Different from electro-hydraulic brakes, this brake takes compressed air as the power source, featuring sensitive action, fast response and strong adaptability to dusty and humid industrial working conditions.

Under normal operating conditions, compressed air pushes the air cylinder to separate the brake shoes from the brake drum, realizing equipment free operation. Once the air supply is cut off, air pressure fails or the system breaks down, the built-in high-strength compression spring will instantly drive the brake shoes to clamp the drum tightly to complete emergency braking, effectively avoiding equipment sliding, runaway and safety accidents.

Equipped with a new high-life pneumatic cylinder and integral clamping brake lining structure, the QW250-40 brake supports high-frequency continuous braking. It adopts automatic gap equalization technology to maintain stable braking clearance for a long time, greatly reducing daily maintenance frequency. It is the standard matching brake for medium and small-tonnage conveying and lifting equipment.

 Core Features & Product Advantages

Strict Fail-Safe Protection: Spring-applied braking and pneumatic release design. Automatic emergency braking when air pressure fails or power is off, which meets international industrial safety standards and ensures zero-risk shutdown of mechanical equipment.

High-Frequency Stable Braking: Matched with high-precision dedicated pneumatic cylinder, featuring sensitive response, fast release and braking speed, uniform braking force, no jitter or impact during frequent start-stop operation, suitable for continuous cyclic working conditions.

Automatic Gap Equalization System: Built-in synchronous gap adjusting mechanism, which automatically compensates the wear of brake lining during long-term operation, keeps consistent braking clearance all the time, avoids single-side friction and drum scratching, and saves manual debugging cost.

Easy Maintenance & Replaceable Lining: Adopts integral clamping non-asbestos brake lining structure. The lining replacement process is simple and fast without disassembling the whole brake, greatly improving maintenance efficiency and reducing operating costs.

Excellent Environmental Adaptability: Optimized sealed structural design, dust-proof and moisture-proof. It can work stably in harsh environments such as mine, port, metallurgy and workshop with large dust and high humidity, with low failure rate.

Adjustable Braking Torque: The braking force can be precisely adjusted by controlling the air pressure (0.4–0.7MPa), which can meet the deceleration and parking braking requirements of different load equipment.

Durable & Long Service Life: Key hinge parts adopt self-lubricating bearings with flexible operation and wear resistance. The spring is protected by anti-rust coating to avoid fatigue damage, ensuring long-term stable operation of the whole machine.

Working Principle

Pneumatic Release (Normal Operation State): When the equipment starts to work, the pneumatic system inputs stable compressed air into the brake cylinder. The air pressure pushes the cylinder piston to drive the mechanical linkage mechanism, overcomes the spring preload, and pushes the brake shoes away from the brake drum. The brake is fully released, and the equipment can operate normally without braking resistance.

Spring Braking (Stop & Emergency State): When the equipment needs to stop, or the air supply is interrupted, air pressure leaks, and the pneumatic system fails, the cylinder pressure disappears instantly. The high-strength reset spring rapidly pushes the brake shoes to tightly fit the 250mm brake drum, generating stable friction braking torque to realize rapid deceleration and safe parking, which completely guarantees the safety of mechanical operation.

Complete Technical Parameters