Coal Mining Machinery IP67 High Precision Gearbox High Power Density &

Product Specification

The dedicated high-precision gearbox for coal mining machinery Extremely High Power Density & Compactness

1. Introduction

The dedicated high-precision gearbox for coal mining machinery is the core transmission component used in shearers, roadheaders, and other coal mining equipment. It operates in the extremely harsh environment of underground coal mines, facing severe challenges such as confined space, heavy loads, impacts, high temperatures, high humidity, high dust, and the presence of explosive gases (methane). Therefore, this type of gearbox requires not only ultra-high power density and reliability but must also comply with the most stringent safety and explosion-proof standards. It is designed to efficiently and reliably transmit power from the motor to actuators like the cutting unit and traction unit, driving the cutting drum rotation or the machine's movement. It is a critical component ensuring efficient and safe coal mining.

2. Advantages

• Extremely High Power Density & Compactness: Utilizes optimized design and premium materials to achieve high power and torque transmission within an extremely limited space, perfectly adapting to the compact layout of coal machinery.

• Exceptional Reliability & Durability: Gears and shafts are made from high-strength alloy steel and undergo precision processes like carburizing, quenching, and grinding, resulting in very high bending strength and contact fatigue strength for long service life.

• Superior Overload & Impact Resistance: Reinforced design to handle the severe shocks and vibrations generated during coal and rock cutting, with a high service factor to effectively cope with instantaneous overloads.

• Efficient Heat Dissipation & Thermal Balance Design: Addresses the sealed, high-temperature environment with poor ventilation underground through special cooling features (e.g., spiral water cooling channels, external coolers) and thermal balance calculations to prevent excessive oil temperature and ensure stable performance.

• Extreme Sealing Reliability: Employs multiple, multi-type seal combinations (e.g., high-quality lip seals, labyrinth seals, floating face seals) to extremely effectively prevent the ingress of external coal dust and muddy water and prevent internal lubricant leakage, ensuring bearings and gears operate in a clean environment.

• Stringent Explosion-Proof & Safety Design: All electrical components (e.g., sensors) and structural designs comply with explosion-proof requirements for underground coal mines (e.g., GB standards, ATEX, IECEx), eliminating any risk of igniting methane gas.

• Low Noise & High Precision: High gear accuracy (typically reaching ISO Grade 5-6), good housing rigidity, ensuring smooth transmission and low noise.

• Modularity & Maintenance Convenience: Design considers the difficulty of underground maintenance, striving for modularity to facilitate quick replacement of wear parts and reduce downtime.

3. Key Technical Parameters

• Power Range: From tens of kW to over a thousand kW (e.g., shearer cutting motor power can exceed 800kW).

• Output Torque: High torque, with specific values matching the cutting drum diameter and motor power.

• Ratio Range: Varies based on functional requirements (cutting or traction), typically large.

• Transmission Efficiency: >96% (single stage), high efficiency reduces energy consumption and heat generation.

• Design Standards: Complies with GB (Chinese National Standards), MT (Coal Industry Standards), ISO, DIN, etc., and must pass coal mine safety certification (MA Certification).

• Protection Grade: At least IP67 (Dust-tight and protected against immersion), often higher.

• Cooling Methods: Internal water cooling (cooling channels within the housing), forced external oil circulation cooling, natural cooling, etc.

• Duty Cycle: Typically S1 continuous duty, capable of withstanding frequent starts/stops and heavy shock loads.

4. Applications

• Shearer: Serves as the cutting transmission reducer and traction transmission reducer, acting as the core "joints" of the shearer.

• Roadheader: Drives the cutting head rotation for tunnel driving.

• Continuous Miner: Performs both cutting and loading functions.

• Plow System: Drives the plow unit.

• Other Underground Coal Mining Equipment: Such as drive units for head and tail ends of heavy-duty armored face conveyors (AFC).