VSI251055-N Slewing Bearings

VSI251055-N Slewing Bearings — INA VSI25 Internal Gear Four-Point Contact Ball Slewing Ring

VSI251055-N Slewing Bearings sit at the top of the INA VSI Standard 25 internal-gear family — a single-row four-point contact ball slewing ring with a 910 mm bore, 80 mm section height, and 165 kg weight. Its static axial load capacity of 3,750 kN makes it the heaviest-rated ring in the series, suited to heavy crane slewing sections, wind turbine yaw drives, and other large rotating platforms where combined axial, radial, and tilting moment loads must be carried simultaneously.

What Is the VSI251055-N?

The VSI251055-N is a single-row four-point contact ball slewing ring in the INA VSI Standard 25 series. Its four-point contact ball geometry allows one ball row to carry axial, radial, and tilting moment loads at the same time — a structural advantage over standard radial or thrust bearings in applications where combined loading is the primary design constraint.

The internal gear uses module 10 with 93 teeth, a pitch circle diameter of 930 mm, and a normalized (N) tooth profile. A pinion meshes inside the ring bore, keeping the drive geometry compact and reducing exposure of the gear teeth to external debris. Compared to external-gear designs of similar capacity, this internal-gear layout reduces the total radial envelope — relevant for large rotating platforms and crane slewing sections where radial space is limited.

At C0a = 3,750 kN, this is the highest static axial rating within the INA VSI Standard 25 internal-gear family. Raceways are induction-hardened to 55–62 HRC for surface fatigue resistance, while the ring core retains ductility to absorb shock loads typical in heavy equipment duty cycles.

Full Technical Specifications

Data source: Schaeffler medias official catalogue.

Materials & Construction

The ring body is made of 50Mn or 42CrMo4 alloy steel, both of which are well proven materials in heavy slewing ring manufacturing and have the best combination of core toughness and surface wear resistance. The rolling elements employ GCr15 bearing steel ball. The double-lip NBR seals keep oil in and dust and moisture out across the complete -25 to +80 °C working range.

The VSI251055-N Slewing Bearings has the same footprint as the rest of the VSI Standard 25 series. The standard series layout with 30 × M20 threaded holes on a 994 mm inner bolt circle allows the ring to be replaced or updated on the same machine platform with the same structure for installation.

Precision class alternatives — P0, P6 and P5 — may be selected depending on whether the application demands the normal industrial precision or finer positional control as in antenna mounts or indexing table applications.

Where Is the VSI251055-N Used?

This bearing is designed for applications with high combined loads in a large diameter rotating joint. Common uses are:

· Tower cranes and large mobile cranes – the 1,055 mm raceway and C0a 3,750 kN capacity handling the tilting moments created during big lifts.

· Wind turbine yaw systems — the module 10 internal gear transfers strong yaw drive torques across the whole operating temperature range. The inside-pinion structure fits within nacelle space limits.

· Large excavators (60 to 90 tonne class) – four-point contact geometry maintains clearance stability against recurrent digging shock loads.

· Offshore drilling turntables and deck cranes – the sealed NBR design minimises grease loss and moisture infiltration in damp or humid circumstances.

· Heavy rotary indexing tables and mining shovels – the inside-drive design maintains the pinion in the ring hole, minimising exposure to contamination in abrasive situations.

· Radar dishes and satellite antenna platforms – the regulated radial clearance of 0.03 to 0.13 mm and clearance managed internal gear satisfy positional precision requirements.

Why Source from Heng Guan Bearing?

Luoyang Heng Guan Bearing Technology Co., Ltd. produces slewing rings with diameters from 50 mm to 10,000 mm in the precision grades of P0, P6, P5 and P4. Luoyang has its own manufacturing equipment, such as CNC vertical lathes, CNC quenching machines, CNC gear shapers, grinding machines and big gear hobbing machines. The quality inspection is done using coordinate measuring equipment, vibration testers and life testing devices.

The products are conform to DIN, ISO and GB standards. Heng Guan sells to more than 50 countries including Germany, United States, Norway, Australia and the Middle East markets. The firm is ISO 9001 certified and built to RoHS regulations.

Heng Guan provides this bearing:

·Factory provide direct replacement for INA VSI251055-N OEM/ODM

• MOQ 1 piece, stock models 2-3 business days to ship

· Engineering confirmation within 24 hours of request

• Installation advice, technical consulting and cross reference mapping to current equipment

· Customisation according to 2D designs for unique operating circumstances, non-standard

FAQ

Q: What is the products?

A: It is the largest internal-gear four-point contact ball slewing ring in the INA VSI25 Standard 25 series. The ring has a 910 mm bore, 80 mm section height, and weighs 165 kg, with a static axial capacity of 3,750 kN and a module 10 internal gear with 93 teeth.

Q: How does the VSI25 series differ from the VSI20 series?

A: The VSI25 series uses an 80 mm section height versus 56 mm in VSI20, a module 10 gear versus m5–m8, and M20 fixing threads versus M12. Static axial and tooth force capacity is roughly double at a comparable outer diameter.

Q: What is the difference between VSI251055-N and VSI250955-N?

A: Both use the 80 mm VSI25 section. The VSI251055-N has a 930 mm pitch circle, 93 teeth, and C0a 3,750 kN. The VSI250955-N has 83 teeth and C0a 3,400 kN — approximately 10% lower static axial capacity at the same module 10.

Q: How is the internal gear driven?

A: A pinion meshes inside the ring bore. This arrangement keeps the drive compact, limits tooth exposure to external debris, and reduces the overall radial envelope compared to external-gear designs of similar capacity.

Q: What re-lubrication interval is recommended?

A: For heavy equipment such as cranes and excavators, every 100 operating hours is a common raceway re-lubrication interval. In high-humidity or continuous-rotation conditions, more frequent lubrication is advisable to displace moisture and aged grease.

Q: Is the VSI251055-N available for direct purchase?

A: Yes. Stock units ship in 2–3 business days. MOQ is 1 pc. Contact mia@hgb-bearing.com for availability, pricing, and technical documentation.

Contact Us

For inquiries about VSI251055-N Slewing Bearings, pricing, stock availability, or technical support, contact Heng Guan Bearing at mia@hgb-bearing.com. We respond within 24 hours.