The ED121/6Ex is an Exd I flameproof electro-hydraulic thruster (often marketed as BEd121/6Ex in China) with 1250 N rated thrust, 60 mm stroke, and a fail-safe design, designed for explosive atmospheres like coal mines to drive drum/disc brakes on conveyors, hoists, and underground mining equipment, compliant with GB3836.1/2-2010.
Core Specifications
| Parameter | Value |
|---|---|
| Rated thrust | 1250 N |
| Rated stroke | 60 mm |
| Power consumption | 330 W |
| Rated current (400 V/50 Hz) | 1.2 A |
| Duty cycle (S3-60%) | 2000 cycles/hour |
| Explosion-proof mark | Exd I (GB3836.1/2-2010) |
| Insulation class | F |
| Protection class | IP65 |
| Ambient temperature | -20 °C to +40 °C |
| Weight | ~39 kg |
| Hydraulic oil | ISO VG 32/46 |
| Voltage options | 380 V/660 V/1140 V (3-phase, 50 Hz) |
Structure & Working Principle
Structure: Integrates a flameproof motor, centrifugal pump, sealed oil cylinder, piston pushrod, and balanced air chamber; cast aluminum alloy housing for light weight and corrosion resistance.
Fail-Safe Operation:
Power-on: Motor drives the pump to generate hydraulic pressure, extending the pushrod to release the brake.
Power-off: Pressure drops; internal springs retract the pushrod, engaging the brake.
Balanced air chamber allows 0–180° installation for flexible mounting.
Key Advantages
Flameproof safety: Exd I certification for underground coal mines; sealed flameproof joints prevent ignition sources.
Compact & durable: Integrated design reduces installation space; F-class insulation motor ensures long life.
Stable performance: Non-oil-immersed motor; special surface treatment on the pushrod extends seal life.
Flexible installation: Balanced air chamber enables any orientation mounting.
Applications
Primary: Drive for explosion-proof drum/disc brakes on coal mine belt conveyors, hoists, and underground transport vehicles.
Secondary: Suitable for metallurgy, ports, and heavy material handling with explosive risks; replaces non-explosive ED thrusters in hazardous areas.
Installation & Maintenance
Installation:
Mount on a rigid base; ensure pushrod alignment with the brake actuator.
Use certified explosion-proof cables and proper grounding; keep flameproof surfaces clean and undamaged.
Fill with ISO VG 32/46 hydraulic oil to the level mark; bleed air before commissioning.
Maintenance:
Daily: Check oil level, leaks, and abnormal noise; clean the air breather and surface.
6 months: Inspect oil quality; replace if degraded or contaminated.
12 months: Overhaul seals; check motor insulation (≥2 MΩ); verify flameproof joint gaps (≤0.2 mm).
Never modify flameproof components; use only original spare parts.
