VSI250755-N Slewing Bearings
Gear: Internal gear, module m10 / 63 teeth, pitch circle d0 per medias official data
Dimensions: bore 610 mm × OD 855 mm × height 80 mm, weight 119 kg (Schaeffler medias official)
Load capacity: dynamic axial Ca = 340 kN, static axial C0a = 2,700 kN, dynamic radial Cr = 305 kN, static radial C0r = 1,230 kN
Tooth force Fz max = 98.9 kN (per medias data)
Max. radial load on fixing screws Fr zul = 290.4 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 VSI Standard 25 family across the 414 → 1094 (or 755 → 1055) raceway range
Primary application: Heavy Excavators and Cranes (25-series mid-size)
- Product Description
VSI250755-N Slewing Bearings — INA VSI Standard 25 Internal Gear Four-Point Contact Ball Slewing Ring
The VSI250755-N Slewing Bearings is a single row four point contact ball slewing ring from the INA VSI Standard 25 series with a raceway diameter of 755 mm, a m10/z63 internal gear and a static axial load capability of 2,700 kN. The bearing is intended for big excavator swing systems and crane slewing sections where combined axial, radial and tilting moment loads have to be borne concurrently. It has a bore of 610 mm, an outer diameter of 855 mm and a height of 80 mm with a weight of 119 kg.
What Is the VSI250755-N?
The VSI250755-N is an internal-gear slewing ring in which the gear teeth are cut inside the ring bore. This configuration allows the drive pinion to mesh from within the ring, keeping the swing drive assembly compact and positioned away from external debris — a standard layout for excavator swing drives and crane pivot systems.
The four-point contact ball structure enables a single ball row to carry axial, radial, and tilting moment loads at the same time, reducing the number of bearing rows required in the assembly.
The ring operates from −25 °C to +80 °C. Double-lip NBR seals on both faces limit ingress of dust and moisture in outdoor and construction environments.
Full Technical Specifications
Parameter | Value |
Model | VSI250755-N |
Raceway Diameter (DL) | 755 mm |
Inner Ring Bore (di) | 610 mm |
Outside Diameter (Da) | 855 mm |
Total Height (H) | 80 mm |
Weight | 119 kg |
Gear Module (m) | 10 mm |
Number of Teeth (z) | 63 |
Gear Pitch Circle (d0) | 630 mm |
Dynamic Axial Load (Ca) | 340 kN |
Static Axial Load (C0a) | 2,700 kN |
Dynamic Radial Load (Cr) | 305 kN |
Static Radial Load (C0r) | 1,230 kN |
Max. Tooth Force (Fz peak) | 98.9 kN |
Max. Radial Load on Fixing Screws (Fr zul) | 290,400 N |
Outer Bolt Circle (La) / Qty | 815 mm / 24 holes |
Inner Bolt Circle (Li) / Qty | 694 mm / 24 × M20 |
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 |
Source: Schaeffler medias official catalogue (retrieved 2026-08-17)
Design and Construction Details
Geometry of four point contact ball.A single row ball bearing may carry the axial, radial and tilting moment loads in one package. This is especially the case for low-speed, combined-load applications, such as excavator swing systems and crane slewing sections, which are difficult to equip with many rows of bearings.
Internal gear with standard (N) profile.The m10/z63 gear has a max tooth force up to 98.9 kN per Schaeffler medias catalogue data. The pinion engages with the inner ring bore, thus the driving mechanism is contained inside the footprint of the machine.
High static load capacity.A 2,700 kN C0a on a 755 mm racetrack in an 80 mm section height can withstand permanent raceway deformation under strong digging and lifting stress loads.
Series compatible with envelop.The VSI Standard 25 mounting interface is size specific over the 755 to 1055 mm raceway range, therefore ensuring bolt patterns and connection dimensions are consistent whether replacing or upgrading within the series.
Choice of materials.The ring steel is 50Mn or 42CrMo4 (quenched and tempered). Induction hardened raceways (55-62 HRC) withstand fatigue while the core is ductile to absorb shock loads. Balls are bearing steel GCr15.
Application Areas
This bearing is used where a mid-size 25-series internal-gear slewing ring is required:
· Heavy excavators — swing system connecting the upper carriage to the undercarriage; handles shock loads and debris ingress during continuous operation
· Mobile and overhead cranes — slewing section and gantry pivot with inside pinion meshing
· Wind turbine yaw systems — sealed four-point design rated for outdoor operation across the full −25 to +80 °C temperature range
· Mining shovels and drill rigs — high-shock turntable applications with internal pinion drives
· Large rotary indexers and test platforms — positions the drive inside the table footprint
· Radar and antenna platforms — large-diameter tracking with central pinion drive
· Offshore and marine deck equipment — NBR-sealed construction for salt-spray environments
About Heng Guan Bearing
Luoyang Heng Guan Bearing Technology Co., Ltd. is a manufacturer specializing in the research, development, and production of slewing bearings ranging from 50 mm to 10,000 mm in diameter. The production floor includes CNC vertical lathes, CNC quenching machines, CNC gear shapers, large gear hobbing machines, grinding machines, and machining centers.
Dimensional and functional inspection is carried out using coordinate measuring machines, vibration testers, and life testing machines. All processes are documented for traceability from raw material to finished product. Products are manufactured to ISO 9001 quality management standards and comply with DIN, ISO, and GB dimensional standards.
For VSI250755-N Slewing Bearings orders, the following terms apply:
· MOQ: 1 pc
· OEM/ODM support available for non-standard configurations
· Installation guidance provided with each order
· Stock units are available; Contact Us to confirm current availability and lead time
FAQ
Q: What is the VSI250755-N?
A: It is an internal-gear, four-point contact ball slewing ring from the INA VSI Standard 25 series. The ring measures 610 mm bore × 855 mm OD × 80 mm height and weighs 119 kg.
Q: What are the gear specifications?
A: Internal gear, module 10, 63 teeth, 630 mm pitch circle diameter, normalized (N) tooth profile. Peak tooth force is 98.9 kN per Schaeffler medias catalogue data.
Q: How does VSI250755-N differ from VSU250755?
A: Both use a 755 mm raceway in the Standard 25 series. VSI250755-N has an internal gear (610 × 855 × 80 mm, 119 kg, m10/z63). VSU250755 is gearless (655 × 855 × 63 mm, 89.1 kg). The appropriate choice depends on the drive configuration of the machine.
Q: What bolt grade is required for mounting?
A: High-strength bolts of grade 10.9 or 12.9 (ISO) are required. The unthreaded shank must sit in the shear plane; fully threaded bolts must not be used. The inner bolt circle uses 24 × M20 threaded holes on a 694 mm bolt circle diameter.
Q: How often should the bearing be re-lubricated?
A: For heavy equipment such as excavators, re-lubricating the raceway every 100 operating hours is a standard interval. In high-humidity environments, increasing the frequency helps flush out moisture and contaminants.
Q: Is the VSI250755-N available from stock?
A: Stock units are available. Contact us at mia@hgb-bearing.com to confirm current availability and pricing.
Contact Us
For inquiries about VSI250755-N Slewing Bearings, pricing, availability, or technical specifications, contact Heng Guan Bearing directly: mia@hgb-bearing.com
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