The dedicated extrusion gearbox for brick and tile machinery Optimized Sealing Structure

1. Introduction

The dedicated extrusion gearbox for brick and tile machinery is the core power transmission component of both vacuum and non-vacuum brick machines, commonly known as the "extruder reducer" or "brick machine main shaft." Positioned between the motor and the extrusion screw, its primary function is to convert the high-speed rotation of the motor into the low-speed, ultra-high torque rotational movement required by the extrusion screw. It operates under conditions of continuously enduring immense back pressure (from the compressed clay) and severe shock loads, in a typically dusty and humid environment. Its performance and reliability directly determine the quality of green bricks, production output, and the overall machine's operational stability.

2. Advantages

• Exceptional Load Capacity & Torque Output: Features a heavy-duty design. Gears and shafts are made from high-strength alloy steel, undergo carburizing quenching, and are precision ground, resulting in extremely high bending and contact fatigue strength. This enables continuous output of massive torque to extrude high-hardness clay.

• Superior Shock Resistance: Designed to handle instantaneous severe shocks caused by hard objects (e.g., stones) jamming or uneven clay consistency. It boasts a high service factor and overload capacity, with a rigid housing that effectively absorbs and dampens impacts.

• Optimized Sealing Structure: Utilizes multiple sealing combinations (e.g., labyrinth seals, lip seals, sometimes air purge seals) to effectively prevent the ingress of contaminants in humid, dusty environments and prevent lubricant leakage, protecting bearings and gears.

• High Transmission Efficiency & Thermal Balance Design: Precision gear machining and optimized bearing arrangements ensure high transmission efficiency, reducing energy loss and heat generation. Larger models often incorporate cooling devices (e.g., fans, water-cooling coils) to ensure temperature rise remains within allowable limits during continuous heavy-duty operation.

• Compact Structure & Reliable Connection: Often designed for integration with the host machine. The output end connects to the extrusion screw via a heavy-duty coupling (e.g., gear coupling) or direct flange connection, ensuring reliable alignment and efficient power transmission.

• Ease of Maintenance: Designed with accessible inspection covers, drain plugs, and lifting points for easy daily oil level checks and routine maintenance.

3. Key Technical Parameters

• Power Range: Very wide, from 30kW to over 400kW, depending on the brick machine model and output.

• Output Torque: Extremely high, a core parameter, reaching tens of thousands to hundreds of thousands of Newton-meters (N.m).

• Output Speed: Very low, typically between 10-25 rpm, to match the extrusion speed of the clay.

• Reduction Ratio: Very large, typically between 20:1 and 50:1 or higher.

• Center Height / Output Shaft Specification: Matches the extrusion screw diameter; a critical installation dimension.

• Service Factor: High (typically ≥ 2.0), ensuring sufficient strength reserve for shock loads.

• Lubrication Method: Splash lubrication or forced circulation lubrication (for large models).

4. Applications

This type of gearbox is dedicated to the extrusion section of various brick-making machines:

• Vacuum Brick Machines: Core equipment for producing high-quality products like hollow bricks, perforated bricks, and insulating blocks.

• Non-Vacuum Brick Machines: For producing solid standard bricks, paving bricks, etc.

• Double-Stage Vacuum Extruders: Both the first stage (upper stage) for mixing/extrusion and the second stage (lower stage) for vacuum extrusion are driven by heavy-duty gearboxes.

• Other Similar Extrusion Equipment: Also used in analogous clay extrusion processes in industries like pottery, refractories, and ceramics.