The DYW400-1200 (BEd121/6) is a heavy-duty explosion-protected electro-hydraulic drum brake from the DYW series, integrated with the BEd121/6 explosion-protected electro-hydraulic thruster as its core drive component. It features a drum diameter of 400 mm, a braking torque range of 1200 N·m, and flameproof protection design, complying with GB 3836/IEC 60079 explosion-proof standards (Ex d IIC T4 Gb/Ex tD A21 IP65 T135°C). Engineered for safe and reliable braking of heavy-load equipment in hazardous environments, it is widely used in flammable, explosive, or dust-laden industrial scenarios. Details of its core parameters, working principle, key features, and typical applications are as follows:
1. Core Parameters
| Parameter Category | Specific Values |
|---|---|
| Product Model | DYW400-1200 (BEd121/6) |
| Brake Type | Explosion-protected electro-hydraulic drum brake (normally closed) |
| Drum Diameter | 400 mm |
| Rated Braking Torque | 1200 N·m |
| Matching Thruster | BEd121/6 explosion-protected electro-hydraulic thruster |
| Thruster Rated Thrust | 1210 N (BEd121/6) |
| Thruster Rated Stroke | 60 mm (BEd121/6) |
| Explosion-Proof Rating | Ex d IIC T4 Gb (gas zone); Ex tD A21 IP65 T135°C (dust zone) |
| Rated Voltage (Thruster) | 380V three-phase AC (optional 220V AC) |
| Thruster Rated Power | 1.1 kW (BEd121/6) |
| Operating Frequency | ≤1200 cycles per hour |
| Braking Response Time | ≤0.5 seconds |
| Release Response Time | ≤0.6 seconds |
| Protection Class | IP65 |
| Operating Temperature Range | -10°C to 60°C |
| Equipment Weight | ≈180 kg |
| Compliance Standards | GB 3836.2-2010, GB/T 18839-2019, IEC 60079 |
2. Working Principle
The brake adopts a "normally closed + explosion-protected electro-hydraulic drive" design, with the BEd121/6 thruster providing power. Its operation relies on the coordination of hydraulic thrust and brake spring force, divided into three core stages:
2.1 Brake Release (Power-On Stage)
When the host equipment needs to operate, the BEd121/6 explosion-protected thruster is energized. Its built-in explosion-proof motor drives the hydraulic pump to generate 12–16 MPa hydraulic pressure, pushing the thruster's push rod to extend linearly.
The push rod transmits force to the brake's lever mechanism, compressing the high-tension brake spring (60Si2MnA alloy steel) and driving the two brake shoes to separate outward from the drum.
A 0.3–0.5 mm uniform clearance is formed between the brake linings (asbestos-free resin-based composite, wear-resistant and high-temperature resistant) and the brake drum, allowing the drum to rotate freely with the equipment's rotating shaft-completing the release action.
2.2 Braking Engagement (Power-Off Stage)
When the equipment stops or an emergency occurs, the thruster is de-energized. The hydraulic system relieves pressure, and the thruster's push rod retracts under the action of its internal return spring.
The brake spring rebounds rapidly, pushing the brake shoes to clamp inward toward the rotating brake drum. The friction between the linings and the drum generates 1200 N·m braking torque, decelerating the equipment until it stops and maintaining a locked state.
In case of sudden power failure or thruster malfunction, the normally closed design ensures the brake automatically engages, preventing equipment runaway in hazardous environments.
2.3 Safety Protection Mechanisms
Overload & Overheat Protection: The BEd121/6 thruster is equipped with a thermal protector (F-class insulation) that cuts off power when the motor temperature exceeds 155°C. The brake's built-in relief valve prevents hydraulic system overpressure, avoiding component damage.
Explosion-Proof Safety: All electrical components (thruster motor, position sensor) adopt flameproof enclosures with minimal explosion gaps (≤0.2 mm), preventing internal sparks from igniting external flammable gases or dust. Explosion-proof cable glands seal electrical connections to block gas/dust intrusion.
Wear Compensation: A built-in automatic wear adjuster compensates for up to 10 mm of lining wear, maintaining consistent braking torque and clearance without manual calibration.
Interlock Control: Explosion-proof position sensors output "released" and "engaged" signals, enabling interlock with the host equipment-ensuring the host can only start when the brake is fully released, and stops immediately when the brake engages.
