VSU250855 Slewing Bearings

VSU250855 Slewing Bearings — INA VSU25 Series Gearless Four-Point Contact Ball Slewing Ring

VSU250855 Slewing Bearings belong to the INA VSU Standard 25 heavy series — a gearless, single-row, four-point contact ball slewing ring with an 855 mm raceway diameter, 955 mm outside diameter, 63 mm section height, and 101 kg weight. Rated at 3,050 kN static axial load, it is designed for heavy excavators, tower cranes, and other equipment where combined axial, radial, and tilting moment loads occur simultaneously under shock conditions. Luoyang Heng Guan Bearing Technology Co., Ltd. manufactures and supplies this model from its Luoyang, China facility.

What Is the VSU250855?

The VSU250855 is a gearless single-row four-point contact ball slewing ring in the INA VSU Standard 25 series. Its raceway diameter is 855 mm, bore is 755 mm, outside diameter is 955 mm, and total height is 63 mm — all within the standard VSU25 series envelope.

The four-point contact ball design allows a single row of GCr15 balls to carry axial, radial, and tilting moment loads simultaneously. This makes the ring well suited for applications where combined loading and shock absorption are both required.

Because neither ring carries gear teeth, it is classified as a gearless slewing ring. Rotation is transferred through an external pinion on a customer-machined OD, a chain or belt drive, a friction wheel, or a hydraulic or electric motor via gearbox, allowing flexible drive options for different machine layouts.

Ring material is 50Mn or 42CrMo4 steel, with raceways induction-hardened to 55–62 HRC for surface fatigue resistance while the core remains ductile to absorb shock. Double-lip NBR seals provide contaminant exclusion, keeping lubricant in and debris out across an operating temperature range of -25 to +80 °C.

VSU250855 Full Specifications

Dimensional and load data sourced from the Schaeffler medias official catalogue.

Key Technical Details

High static capacity in a compact section. The C0a of 3,050 kN at the 855 mm raceway sits within a 63 mm section height. Compared with the VSU250755 (C0a 2,700 kN, 89 kg), the static axial capacity is approximately 13% higher while the section height and bolt pattern remain unchanged.

Series 25 versus Series 20. Series 25 uses a 63 mm section versus 56 mm in Series 20, and 22 mm fixing bores versus 14 mm. Static axial capacity at a comparable outside diameter is roughly double that of the 20 series. When a Series 20 ring is load-limited in a 40–60 tonne class excavator swing system, Series 25 is the direct upgrade path.

Standard series envelope. Each size in the 25 series has its own fixing pattern — 24 holes on 815 / 695 for the 755, 28 on 915 / 795 for the 855, and 30 on 1,015 / 895 for the 955 — so hole counts and both pitch circles change with the diameter. A worn unit of the same designation can be replaced directly; moving up a size requires the mating structure to be re-checked.

Drive flexibility. The absence of gear teeth on the ring reduces ring manufacturing complexity. The drive method — external pinion, chain, friction wheel, or motor gearbox — is determined by the machine designer based on layout requirements.

Material and sealing. 50Mn and 42CrMo4 rings with GCr15 balls and double-lip NBR seals are suited to continuous outdoor exposure and the shock load profiles typical of mining shovels, marine deck cranes, and heavy rotary indexing tables.

Typical Application Areas

· Heavy excavators (40–60 tonne class): Swing systems where Series 20 reaches its load limit. The 3,050 kN static axial rating provides margin against digging shock loads.

· Tower cranes and mobile cranes: Slewing sections stepping up from the 20-series when hook loads increase beyond the lower series capacity.

· Wind turbine yaw systems: Gearless rings with external pinion drives where raceway gear machining is not required; the -25 °C lower temperature limit covers cold-climate installations.

· Mining shovels and aggregate equipment: Four-point contact ball design handles severe shock loads in dusty and wet environments, protected by double-lip NBR seals.

· Heavy rotary indexing tables: Chain or friction-wheel driven gearless rings; the 28-hole bolt pattern is compatible with large turntable mounting flanges.

· Offshore and marine equipment: Marine winches and deck cranes where the sealed design and NBR material suit humid, salt-air environments.

· Utility-scale solar trackers: Large pivot envelopes with high tilt-moment requirements paired with linear-actuator or friction drives.

Manufacturing and Quality

Every VSU250855 Slewing Bearings unit produced at the Luoyang facility goes through coordinate measuring machine inspection, vibration testing, and life testing before shipment. Raw materials carry full traceability from incoming steel to finished ring.

Production equipment includes CNC vertical lathes, CNC quenching machines, CNC gear shapers, machining centers, grinding machines, and large gear hobbing machines. Precision classes P0, P6, and P5 are available as standard; reduced-clearance and preloaded variants are available on request.

OEM and ODM partnerships are supported. MOQ is 1 piece for both standard and non-standard orders. Standard stock models ship within 5–7 days. Engineering confirmation is provided within 24 hours of inquiry. Services include technical consultation, product design, installation guidance, dimensional mapping of worn units, and non-standard customization with 2D drawings.

FAQ

Q: What is VSU250855?

A: VSU250855 is a gearless four-point contact ball slewing ring in the INA VSU Standard 25 series. It has an 855 mm raceway diameter, 755 mm bore, 955 mm outside diameter, and 63 mm section height, weighing 101 kg.

Q: What is the load capacity of VSU250855?

A: Dynamic axial Ca = 355 kN, static axial C0a = 3,050 kN; dynamic radial Cr = 320 kN, static radial C0r = 1,400 kN. Data is from the Schaeffler medias official catalogue.

Q: What is the difference between VSU250855 and VSU250755?

A: Both share the Series 25 envelope and 63 mm section height. VSU250855 has an 855 mm raceway, weighs 101 kg, and is rated at C0a 3,050 kN. VSU250755 has a 755 mm raceway, weighs 89 kg, and is rated at C0a 2,700 kN — approximately a 13% difference in static axial capacity between the two models.

Q: What precision and clearance options are available?

A: Normal radial clearance is 0.03–0.13 mm. Precision classes P0, P6, and P5 are standard. Reduced-clearance and preloaded variants are available on request.

Q: What lubrication practice is recommended?

A: Lubrication intervals depend on the specific application, operating load, and environment. Consult your equipment manufacturer's maintenance manual or contact our technical team for guidance based on your actual operating conditions.

Q: How do I get pricing and availability?

A: MOQ is 1 piece. Standard stock models ship within 5–7 days. Contact our team for current availability, dimensional drawings, and pricing on products.

Contact Us

For pricing, availability, technical drawings, or customization inquiries on VSU250855 Slewing Bearings, contact Luoyang Heng Guan Bearing Technology Co., Ltd. at mia@hgb-bearing.com.