Slewing bearings from BigWings
Day after day, BW® slewing bearings prove themselves as reliable rotational connection elements in a wide range of application areas. Worldwide, we always offer solutions that are unique in terms of design, quality, material selection and performance. The design and production are exactly carried out according to the individual customer requirements.
The diversity of applications and the function of the large diameter bearings is also reflected in the range of dimensions in which they are supplied:
Single-piece forging: diameters of up to 8,000 mm
Segmented bearing: diameters of up to 18,000 mm
Our Products
The production process - how a ring is turned into a slewing bearing
Turning
Initially, the seamless rolled ring undergoes machining.
The ring is centrally positioned on the horizontal table of a CNC vertical lathe. After one side is completed, the ring is rotated to allow for machining on the opposite side.
During this phase, the CNC program precisely controls the turning of various contours. These contours include surfaces, pilots, steps, seal grooves, chamfers, and raceways designed for the bearing’s rollers or balls.
Gear Cutting
Gears can be machined on either the outer or inner ring. The designated tools make multiple passes to cut the gears. The gear cutting process can be carried out using one of the following methods:
- Gear hobbing
- Gear shaping”
Hardening
Hardening enhances the wear resistance and extends the service life of the raceways and gear teeth. Surfaces subjected to high stress are hardened through an induction process. This typically includes the raceways and, when necessary, the gear teeth.
The specific hardening technique applied depends on the product’s intended use, such as:
- Gear hardening
- Raceway hardening
BigWing Tech has developed a globally unique and patented process for full-surface hardening without any soft spots. This technique is especially used for high-speed bearings, like rotor bearings in wind turbines.
Drilling
Drilling is the initial step, followed by the creation of chamfers at both the top and bottom of the hole’s entrance. If necessary, threads can be added to the bore.
Multiple bores are aligned in rows along the axial direction to facilitate mounting the bearing and supporting the load. Threaded holes are also included between them to accommodate stop screws, allowing the bearing to be lifted by crane.
Raceway Finishing
Depending on the design and the required tolerances, the final finishing of the product is achieved through either hard turning or grinding, or sometimes a combination of both.
To ensure optimal surface quality, the raceways and contact surfaces are machined with a hard ceramic cutting tool before assembly.
Assembly
For assembly, the rings are placed on a rotating table, where the designated number of balls or rollers is inserted into the raceway.
Next, seals are installed between the outer and inner rings on both the top and bottom sides, and the gap between the rings is carefully inspected for uniformity.
Afterward, the slewing ring undergoes lubrication, cleaning, and the application of a surface coating.
Quality Assurance and shipping of a slewing bearing
The final inspection of the completed product is conducted internally by our certified quality assurance department, or in collaboration with the customer and/or a designated third party. During this inspection, the functionality and geometry of the product are thoroughly examined. The inspection is based on the specifications agreed upon during the design phase or those outlined in the contract. The results are documented in a written test report and included in the QA documentation, the scope of which is determined in advance with the customer.
Once the final inspection is completed, the slewing ring is prepared for packaging by our logistics department and made ready for shipment. The transport may be arranged directly to the construction site or initially to a seaport or airport. If standard transportation methods are not feasible, special trucks, ships, or aircraft are utilized.
