NTN cylindrical roller bearings NUPK307NR 35x80x21mm
The NTN NUPK307NR is a precision-engineered single-row cylindrical roller bearing, optimized for heavy radial load applications and precise axial positioning. Designed with NTN’s advanced manufacturing technology and premium materials, this bearing delivers exceptional durability, low vibration, and stable performance in industrial scenarios such as gearboxes, motors, and heavy-duty machinery.
The NTN NUPK307NR is a precision-engineered single-row cylindrical roller bearing, optimized for heavy radial load applications and precise axial positioning. Designed with NTN’s advanced manufacturing technology and premium materials, this bearing delivers exceptional durability, low vibration, and stable performance in industrial scenarios such as gearboxes, motors, and heavy-duty machinery.
Core Attributes & Designation Breakdown
| Code | Meaning |
|---|---|
| NUP | Single-row cylindrical roller bearing with double ribs on inner ring, no rib on outer ring; accommodates heavy radial loads and unidirectional axial loads |
| K | Pressed steel cage, featuring high rigidity, excellent roller guidance, and adaptability to high-temperature working conditions |
| 307 | Size series (30) + bore diameter code (07 = 35 mm, calculated as 07×5) |
| NR | Outer ring with integrated snap ring groove and snap ring; enables quick axial fixing in housing, saving installation space |
Key Specifications
| Parameter | Value |
|---|---|
| Bore diameter (d) | 35 mm |
| Outer diameter (D) | 80 mm |
| Width (B) | 21 mm |
| Minimum chamfer (r₁) | 1 mm |
| Basic dynamic load rating (Cr) | 63.0 kN |
| Basic static load rating (C0r) | 61.5 kN |
| Limiting speed (grease lubrication) | 7,500 min⁻¹ |
| Limiting speed (oil lubrication) | 10,000 min⁻¹ |
| Clearance class (typical) | C3 (increased radial internal clearance for thermal expansion compensation) |
| Material | Chrome steel (SUJ2/GCr15) - high wear resistance and fatigue strength |
| Weight | Approximately 0.42 kg |
Performance Advantages
- Dual Load Bearing Capacity: The NUP structure supports heavy radial loads and unidirectional axial loads, making it suitable for equipment with combined load requirements (e.g., gearbox input shafts).
- Simplified Installation: The NR snap ring design eliminates the need for additional retaining components, enabling fast axial fixing in the housing and reducing assembly time and labor costs.
- Stable High-Speed Operation: The K-type pressed steel cage ensures uniform roller spacing, minimizes friction and heat generation during high-speed rotation, and maintains smooth operation even under variable load conditions.
- Strong Environmental Adaptability: The standard C3 internal clearance compensates for thermal expansion of shafts and housings in high-temperature environments, preventing bearing seizure and extending service life.
- Premium Durability: Made of high-grade chrome steel with precision-ground raceways, the bearing exhibits excellent wear resistance and fatigue performance, suitable for long-term continuous operation in harsh industrial settings.
Application Scenarios
This bearing is widely used in:
- Industrial gearboxes and reducers
- Electric motors and generators
- Centrifugal pumps and compressors
- Agricultural machinery and construction equipment
- Textile machinery and printing equipment
Installation & Maintenance Guidelines
- Mounting: Press-fit the bearing onto the shaft; use the outer ring snap ring to fix it axially in the housing. Avoid direct hammering on the bearing to prevent raceway damage.
- Lubrication: Select lubricants based on operating speed and temperature. Grease lubrication is recommended for general applications, while oil lubrication is preferred for high-speed or high-temperature working conditions.
- Alignment: Ensure precise alignment between the shaft and housing to avoid edge loading, which can cause premature bearing failure.
- Contamination Prevention: Keep the installation environment clean and use sealing components to block dust, debris, and corrosive media from entering the bearing interior.
