Large Gearbox Housings

Large Custom Gearbox Housing Manufacturing

In heavy industries such as wind energy, marine propulsion, and mining, large gearboxes endure immense torque and extreme operational stresses. The housing itself must provide absolute structural rigidity to ensure perfect shaft and bearing alignment over decades of continuous use.

Openex specializes in the turnkey fabrication and high-precision CNC machining of massive, custom gearbox housings. Whether your design calls for a heavy plate steel weldment or the precision machining of a massive iron casting, our 180-acre facility has the heavy lifting capacity, stress-relieving furnaces, and large-scale boring mills to execute your blueprints flawlessly.

Gearbox Housing Specifications & Capabilities

We routinely manufacture split-case and single-piece housings for planetary, helical, and bevel gear systems. Below are our general facility capacities:

Maximum Dimensions Up to 15,000 mm (Length/Width)
Maximum Weight Up to 250 Tons
Materials Handled Carbon Steel (A36, Q345), Alloy Steel Plate Weldments, Ductile/Nodular Iron Castings.
Machining Tolerances Strict dimensional and geometric tolerances (GD&T) for bearing journals and dowel pin alignments.
Key Applications Wind Turbine Nacelles, Marine Gearboxes, Mining Crushers, Steel Mill Drives.

Our Work: Large Gearbox Housings

Machined Large Flange on Shop Floor
Heavy VTL Machining of Bearing Housing
heavy machining housings
CNC Machining Heavy Housing Components

The Manufacturing Lifecycle

Building a housing that won't warp under torque requires a strict, metallurgically sound process. Here is how we ensure perfect dimensional stability:

1
Heavy Plate Weldments

For fabricated housings, our AWS-certified welders utilize deep-penetration SAW and FCAW processes to assemble the heavy plates and internal ribbing, ensuring maximum rigidity and zero weld defects.

2
Thermal Stress Relief (PWHT)

This is the most critical step. We place the massive welded assembly into our on-site heat treatment furnaces. By carefully raising and lowering the temperature, we relieve internal residual stresses, preventing the housing from warping during machining or operation.

3
5-Axis Machining & Boring

The stress-relieved housing is moved to our massive floor-type horizontal boring mills and gantry CNCs. We simultaneously bore perfectly concentric bearing journals on opposite sides of the housing to guarantee flawless gear alignment.

4
CMM Dimensional Inspection

Using large-scale Coordinate Measuring Machines (CMM) and laser trackers, we verify that every bore diameter, surface flatness, and dowel pin location meets your exact GD&T blueprint callouts.