VSA250955-N Slewing Bearings
Gear: External gear, module m9 / 120 teeth, pitch circle d0 per medias official data
Dimensions: bore 855 mm × OD ? mm × height 80 mm, weight 155 kg (Schaeffler medias official)
Load capacity: dynamic axial Ca = 370 kN, static axial C0a = 3,400 kN, dynamic radial Cr = 335 kN, static radial C0r = 1,560 kN
Tooth force Fz max = 80.2 kN (per medias data)
Max. radial load on fixing screws Fr zul = 363.0 kN (friction-locking mount)
Clearance spec: Normal: 0.03–0.13 mm; precision class P0 / P6 / P5 available
Material: 50Mn / 42CrMo4 rings, GCr15 balls, double-lip NBR seals, -25 to +80 °C operating range
Standard series envelope — mounting-compatible with the whole VSA Standard 25 family across the 414 → 1094 (or 755 → 1055) raceway range
Primary application: Heavy Excavators and Wind Yaw (25-series large)
- Product Description
VSA250955-N Slewing Bearings — INA VSA25 Series External Gear Four-Point Contact Ball Slewing Ring
The VSA250955-N Slewing Bearings belong to the INA VSA Standard 25 series — a single-row, four-point contact ball external gear slewing ring with a 955 mm raceway diameter, 80 mm section height, and 155 kg weight. The external gear runs module 9 with 120 teeth. Static axial load capacity is 3,400 kN. Luoyang Heng Guan Bearing Technology Co., Ltd. manufactures a direct mounting-compatible replacement for this model, covering precision grades P0, P6, and P5.
What Is the VSA250955-N?
The VSA250955-N is an INA VSA Standard 25 series external gear slewing ring designed for heavy-duty rotation systems. It carries axial, radial, and tilting moment loads through a single row of four-point contact balls, which keeps the section compact at 80 mm without requiring a double-row arrangement. Common machine categories include large excavators, wind turbine yaw systems, tower cranes, and solar tracker drives.
The external gear uses a normalized (N) tooth form — module 9, 120 teeth — so a drive pinion meshes from outside the ring OD. That arrangement keeps the pinion accessible for field maintenance, which matters on wind turbine yaw systems installed at height.
Compared to the VSA250855-N (855 mm raceway, C0a 3,050 kN, m9/z109, 145 kg), the VSA250955-N When more load margin is needed, stepping from the 855 to the 955 model raises the static axial capacity by about 11% at the same 80 mm section height — but the larger ring has its own mounting pattern, so the bolt circle must be checked or the flange remade first.
Full Technical Specifications
Parameter | Value |
Model | VSA250955-N |
Raceway Diameter (DL) | 955 mm |
Inner Ring Bore (di) | 855 mm |
Outside Diameter | 1,096 mm |
Total Height (H) | 80 mm |
Weight | 155 kg |
Gear Module (m) | 9 |
Number of Teeth (z) | 120 |
Pitch Circle | 1,080 mm |
Dynamic Axial Load (Ca) | 370 kN |
Static Axial Load (C0a) | 3,400 kN |
Dynamic Radial Load (Cr) | 335 kN |
Static Radial Load (C0r) | 1,560 kN |
Continuous Tooth Force | 55.1 kN |
Peak Tooth Force (Fz peak) | 80.2 kN |
Max. Radial Load on Screws (Fr zul) | 363,000 N |
Outer Bolt Circle / Qty | 1,016 mm / 30 × M20 |
Inner Bolt Circle (Li) / Qty | 895 mm / 30 × 22 mm through-holes |
Radial Clearance (Normal) | 0.03–0.13 mm |
Operating Temperature | -25 to +80 °C |
Ring Material | 50Mn / 42CrMo4 |
Ball Material | GCr15 |
Seal | Double-lip NBR |
Precision Class | P0 / P6 / P5 |
Structure | Single-row four-point contact ball |
Specification data referenced from Schaeffler medias official catalogue.
The rings are made from 50Mn or 42CrMo4 alloy steel with induction-hardened raceways at 55–62 HRC surface hardness. The core remains ductile to absorb shock loads — relevant for excavator swing and mining shovel cycles. GCr15 balls provide fatigue resistance, and the double-lip NBR seals retain grease and block contaminant ingress across the -25 to +80 °C rated range.
Design Features
Single-row four-point contact ball structure
A single ball row handles axial, radial, and tilting moment loads. The 80 mm section height provides that load range without the complexity and weight of a double-row design.
N-profile external gear
A pinion outside the ring OD meshes with the m9 / 120-tooth external gear. The outside-mesh design exposes the pinion, simplifying gear maintenance and replacement.
Capacity static
C0a 3,400 kN at a 955 mm raceway covers 50–70 tonne excavators' digging cycles and utility-scale solar tracker rows' continuous tilt loads.
VSA Standard 25 envelope compatibility
The VSA25 series offers raceway diameters from 755 mm to 1,055 mm, but each size has its unique fixing-hole pattern. The VSA250955-N utilises La 1,016 mm / 30 holes and Li 895 mm / 30 holes, whereas the 0755, 0855, and 1055 sizes have distinct bolt circles and hole Before changing sizes, check the bolt pattern against your mounting flange.
A temperature range
The 42CrMo4 ring and NBR seals allow -25 °C operation. Before commissioning, check grease specifications with engineering for usage below -20 °C.
Application Areas
VSA250955-N Slewing Bearings suits numerous machine types with wide slewing widths and heavy loads:
For heavy excavators (50-70 tonnes), the m9 external gear couples with the swing pinion outside the ring. Sharp tilting moments during digging cycles are covered by the 3,400 kN static margin.
Wind turbine yaw systems: Direct mesh between external gear and outside-mounted driving pinions. Height-mounted devices need less maintenance with the sealed ring.
For tower and mobile cranes, the 955 mm raceway with 3,400 kN static axial load meets the slewing section needs of heavy lifting equipment.
For solar tracker slew drives, worm drives mesh with the external gear. Utility-scale tracker rows' peak tilt moments are handled by the series-25 bearing.
The sealed four-point contact structure of mining shovels and heavy conveyors withstands shock loads, dust, and abrasion in open-pit conditions.
The NBR-sealed construction of maritime and offshore deck equipment allows for salt-spray service on winches and deck cranes.
About Heng Guan Bearing
Precision bearing manufacturer Luoyang Heng Guan Bearing Technology Co., Ltd. has been in business for over 30 years. The firm produces precise grades P0, P6, P5, and P4 slewing bearings from 50 to 10,000 mm. CNC vertical lathes, quenching, gear shapers, grinding, and huge gear hobbing machines are manufacturing equipment. Full material-to-shipment traceability is achieved using coordinate measurement, vibration, and life testing devices.
Products are shipped to over 50 countries, including the US, Germany, UK, Italy, Turkey, Russia, Norway, Australia, and the Middle East. DIN, ISO, GB, and RoHS standards apply to all items. The firm is ISO 9001-certified.
We provide OEM and ODM technical consultancy, installation help, legacy product mapping, and non-standard customisation for unusual operating situations. Standard stock versions are available for single-unit purchases.
FAQ
Q: What are the outer dimensions of the VSA250955-N?
A: Outside diameter 1,096 mm, bore 855 mm, height 80 mm, weight 155 kg. The outer bolt circle has 30 × M20 threaded holes on a 1,016 mm circle; the inner bolt circle has 30 × 22 mm through-holes on an 895 mm circle.
Q: What are the gear specifications?
A: External gear, module 9, 120 teeth, pitch circle 1,080 mm, normalized (N) profile. Continuous tooth force limit is 55.1 kN; peak tooth force limit is 80.2 kN per Schaeffler medias catalogue data.
Q: How does VSA series 25 differ from series 20?
A: Series 25 uses an 80 mm section height versus 56 mm for series 20, module-9 gear versus m5–m8, and M20 fixing threads versus M12. Static axial and tooth force capacities are approximately twice those of comparable series-20 models at similar outside diameters.
Q: Can this bearing operate in sub-zero temperatures?
A: The standard rated range is -25 to +80 °C. For applications consistently below -20 °C, specify a low-temperature synthetic grease and confirm the ring material grade with the engineering team before ordering.
Q: What relubrication intervals apply?
A: For heavy equipment such as excavators, relubrication of the raceway every 100 operating hours is standard practice. For open gearing, every 50 operating hours is recommended. In high-humidity or continuous-rotation environments, automatic lubrication systems help flush out degraded grease and moisture.
Q: Is this a compatible replacement for the OEM INA VSA250955-N?
A: Heng Guan Bearing produces a direct mounting-compatible replacement for the INA products. Bolt patterns, section height, and gear specification are maintained to match the original.
Contact Us
For pricing, stock availability, CAD drawings, or technical enquiries about the VSA250955-N Slewing Bearings, reach our team at mia@hgb-bearing.com.
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