Design, installation & Maintenance

QCB offers one of the widest ranges of slewing rings, slew drives and ring gears available from a single supplier. We manufacture slewing rings and slew drives under the brandname of QCB^® and offer equivalents to other brands such as Torriani Gianni, La Leonessa, BRB Technologies, INA-FAG (now the Schaeffler Group), Roballo, Roth Erde, Rollix Defontaine, Avon, Taperex, Kaydon, Rossi MRI, RKS, SKF, RIMA, IMO, Titanus, Silverthin, PSL, Drecon, Jost, and BPW ! Not only do we have an extensive catalogue reference library, but we also have an extensive in-house interchange system.

The QCB range includes:-

• Trailer rings
• Single row ball bearings (Geared or ungeared)
• Double row ball bearings (Geared or ungeared)
• Single row crossed roller bearings (Geared or ungeared)
• Triple row roller bearings (Geared or ungeared)
• Split design slewing rings
• Wire race bearings with stainless steel or aluminium raceways for military applications
• Ring gears
• Pinions and pinion shafts
• Slewing drives

QCB slewing rings have built a solid reputation for quality, reliability and innovation in design. Most of our sales are “off catalogue” units that have been designed in conjunction with customer engineering teams to solve specific problems. This allows us to offer the slew rings, pinions and drive motors & gearboxes so that you’re assured of a technically sound solution.

Some of our recent special projects include:

• Stainless steel slewing rings for a high radiation area in a nuclear power plant
• High precision wire race bearings for an optical turret system
• A 7 ton triple row bearing for use offshore
• Mobile X-ray scanners
• Large diameter ring gears and pinions for a 32m vertical spooler
• Wind turbine blade bearings
• Slew rings for an offshore wind turbine foundation drilling ring (6 drive motors; 1 000 000 Nm torque!)
• Ship mounted radar systems
• Slew rings for an underwater FPSO mooring system
• Split slew rings for easy assembly on-site
• An 11m segmented ring gear with 10 drive motors

There are others… but we cannot tell you about them as we have signed confidentiality agreements with our clients!

Slewing ring design

NBC Technical has full design capabilities for single row, double row, triple row and combined bearings to 6 500mm (single piece) and 10 000mm (segmented).

Raceway calculations follow standard practices which investigate rolling element crush loads and raceway pressures to obtain indications of factors of safety and expected life under a variety of load conditions. This approach is the same as that used by other major manufacturers.

Gear calculations are performed using licensed software purchased specifically for the task and which is based on all current European and American standards for gear calculations. (e.g. ISO 6336; ISO 1328; DIN 8687; DIN 3990 et al).

Bolt calculations follow the guidelines set out by VDI 2230

NBC uses AUTOCAD 2016 LT and SOLIDWORKS 2016

Quality

All factories used for the manufacture of QCB® slewing rings have current ISO certification and have been audited and selected by NBC Technical staff. These factories are obliged to adhere to the QCB Design and Quality Specifications which cover all aspects of design, materials and manufacture to final wrapping and labelling.

Large diameter bearings are delivered with a basic datapack which includes

1. Ring materials chemical analysis and mechanical properties certificates

2. Full final dimensional report

3. Gear hardness tests

As all QCB® slewing rings are numbered we can tie back to original factory QC reports. On request we can also offer the following

4. Additional mechanical tests if requested (e.g. Charpy tests)

5. Heat treatment reports

6. Rolling element inspection reports (chemical analysis and dimensional tests)

7. MPI inspection of large diameter rollers

8. MPI inspection of gear teeth

9. Raceway hardness and hardness depth certificates

Inspection procedures

All inspection procedures are carried out based on the specific standards applicable in the country of manufacture. Many Chinese standards are adapted from a European or American standard. e.g. GB/T229‐2007 Metallic materials: Charpy pendulum impact test method is adapted from ISO 148‐1:2006 MOD)