1. The Challenge of Long Tubular and Large-Diameter Turning
Manufacturing oil and gas drill collars, API casing pipe couplings, long hydraulic cylinder barrels, and mining rollers presents unique mechanical challenges:
- Workpiece length often exceeds standard lathe center distances.
- Large outer diameters require oversized spindle through-bores so the tube can pass through the headstock.
- Interrupted cuts on cast steel flanges exert heavy cyclical shocks on the spindle bearings and cross-slide guideways.
2. Luzhong Large-Bore Machine Architecture
To meet these demanding industrial applications, Luzhong Machine Tool produces three dedicated large-bore turning solutions:
| Model | Bed Architecture | Spindle Bore | Max Swing | Max Length |
|---|---|---|---|---|
| Luzhong CK6150 | Flat Bed (400mm width) | Ø82 mm | Ø500 mm | Up to 1,500 mm |
| Luzhong CK6160 | Heavy Flat Bed (550mm) | Ø105 mm | Ø630 mm | Up to 3,000 mm |
| Luzhong TCK56 | 45° Slant Bed | Ø86 / Ø105 mm | Ø560 mm | Up to 1,000 mm |
3. Critical Engineering Considerations for Large-Bore Turning
A. Dual-Chuck Spindle Mounting
When turning long drill pipes that pass completely through the headstock, a single front chuck creates cantilever whip at the rear. The Luzhong CK6160 and TCK56 can be factory-equipped with a rear spindle nose adapter to mount a secondary 3-jaw or 4-jaw chuck, stabilizing both ends of the pipe.
B. Induction-Hardened Flat Bedways (CK Series)
For massive workpieces weighing 1,000 to 2,500 kg, the wide 550mm induction-hardened guideways on the CK6160 distribute gravity loading across a broad surface area, ensuring high rigidity and preventing stick-slip during slow-speed threading passes.
C. High Spindle Torque at Low RPM
Cutting coarse API trapezoidal or buttress threads in high-tensile 4145H alloy steel requires massive torque at low speeds (50 to 200 RPM). Luzhong large-bore lathes utilize high-torque AC spindle motors paired with heavy dual-step gearboxes delivering up to 800+ Nm of continuous turning torque.
4. Application Engineering Consultation
Whether you are machining OCTG pipe connections, hydraulic excavator cylinders, or high-pressure ASME flanges, Luzhong application engineers can configure the ideal spindle bore, chuck package, and steady rest capacity for your workshop.
Submit your workpiece specifications to xiuc32860@gmail.com for a tailored tooling and machine quotation.