B28-31 Open Extra Wide Small Bore CVT Driven Pulley Heavy Load Deep Groove Bearing

1. Product Overview

B28-31 non-standard single-row open deep groove ball bearing, overall dimension 28mm inner bore × 60mm outer diameter × 31mm ultra-wide width, small inner hole plus extra wide heavy-duty structural design, fully interchangeable with original NSK B28-31, widely matched to multiple passenger car CVT driven pulley large torque transmission system. Open design without rubber sealing lips, equipped with stamped low-carbon steel cage and factory standard C0 internal clearance, C3 clearance customizable as required. It bears heavy radial load and moderate bidirectional axial load, runs smooth and low-noise under long-time high-torque variable rotation and high-temperature CVT oil working environment inside sealed transmission housing. Manufactured with fully quenched high-purity GCr15 chrome bearing steel and strict micron-level dimensional tolerance control, fully compatible with OEM B28-31 assembly standards. Complete formal quotation will be provided within 24 hours upon inquiry.

2. Key Advantages

• Open through-hole structure allows full circulation of CVT transmission oil for continuous efficient heat dissipation, completely avoids rubber seal aging, swelling and oil leakage failures under long-time high-temperature oil immersion
• Super-finished ultra-smooth deep groove raceway greatly reduces rolling friction coefficient, less heat accumulation during high-speed operation, maintains stable continuous rotation under frequent heavy torque impact during pulley speed shifting
• Extra-wide thick-wall integrated inner and outer rings with high-hardness GCr15 material deliver outstanding wear resistance and anti-fatigue performance, effectively extend the whole service cycle of CVT transmission system
• OEM unified overall installation dimensions, direct plug-and-play replacement without modifying pulley housing, driven shaft and matched installation accessories
• Optimized lightweight stamped steel cage reduces rotation inertia, perfectly adapts to long-term continuous heavy-load high-speed working conditions of CVT variable transmission
• Standard P0 precision grade, P6 accuracy and C3 internal clearance can be customized to meet matching requirements of mainstream auto OEM factories
• Stable mass production capacity with sufficient stock supply, high cost performance for auto repair aftermarket and bulk OEM supporting orders

3. Applications

Universal passenger car CVT driven pulley heavy-load assemblies, automatic transmission differential large torque output shafts, light commercial vehicle heavy-duty torque reducers, medium agricultural machinery transmission core load-bearing moving components.

4. Technical Specifications

Dimension drawings and technical spec sheets can be provided on request.

5. Why Choose GQZ Bearing

25+ years professional manufacturer of B series non-standard CVT & gearbox bearings. All finished bearings pass high-speed continuous rotation test, shock load test and long-cycle fatigue durability test before delivery. Support customized anti-rust surface coating and special high-temperature anti-wear CVT lubricant filling service. One-on-one professional pulley installation technical guidance and formal detailed quotation within 24h for all RFQs. Stable mass production capacity supports long-term bulk aftermarket and OEM orders, factory direct selling price, stable consistent quality and punctual batch delivery.

6. Quality Assurance

• Raw GCr15 steel hardness & chemical composition incoming inspection
• High-precision raceway superfinishing roughness detection
• Open bearing CVT oil circulation high-temperature aging durability test
• Continuous vibration load rotation fatigue life cycle test
• Full dimension tolerance sorting inspection
• 100% visual appearance marking check before packaging
• Random sampling high-speed performance test before shipment

All B28-31 bearings pass multi-process strict factory inspection.

7. CTA

Send bulk inquiry for B28-31 open small bore ultra-wide heavy-load CVT driven pulley bearings and obtain the following full support:

1. Complete formal detailed quotation within 24 hours
2. Standard dimension drawings & pulley press-fit installation operation guidance
3. Custom anti-rust surface treatment and special CVT transmission lubricant filling service
4. Exclusive long-term bulk factory wholesale price without intermediate markup

Large-volume OEM cooperation is welcome anytime.

8. FAQ

Q1: What is the difference between open B28-31 and rubber sealed bearings?
A1: Open bearing has no rubber sealing lips, installed inside closed CVT housing relying on circulating transmission oil for lubrication and cooling; rubber sealed bearings are used for external exposed dusty shafts with independent grease lubrication.

Q2: Can B28-31 replace original NSK OEM bearings directly?
A2: Yes, inner bore, outer diameter and ultra-wide width dimensions are fully consistent, no modification to CVT pulley components required during replacement.

Q3: Applicable lubrication mode?
A3: Designed for CVT circulating transmission oil lubrication; high-speed anti-wear gear grease can be filled if used for independent separate assembly.