1 Model Information & Technical Parameters

Model：BC1B 320811 (Equivalent Specification NJ 203 ECP)

Dimensions

Bore d：17 mm

Outer diameter D：37 mm

Width B：14 mm

Performance Data

Basic dynamic load rating C：19 kN

Basic static load rating C₀：16.6 kN

Reference speed：20000 r/min

Limiting speed：24000 r/min

Equivalent performance grade：SKF Explorer

Technical Attributes

Supply form: Complete bearing

Number of rows: Single row

Bore type: Cylindrical bore

Outer ring flanges: 2

Inner ring flanges: 1

Inner ring feature: Inner ring loose flange

Outer ring locating flange: None

Axial displacement capacity: None (one-way axial locating, no floating allowance)

Cage: Glass fiber reinforced polyamide non-metallic cage

Radial clearance: CN standard clearance

Tolerance class: Normal standard tolerance

Coating: None

Seals: None

Pre-grease: None

Relubrication facility: None

Logistics & Industry Codes

Net weight：0.068 kg

Indicative carbon footprint：0.25 kg CO₂e

eClass code：23-05-09-01

UNSPSC code：31171505

Model Description

BC1B 320811 is a reference part number with internal structure equivalent to NJ203ECP single row cylindrical roller bearing. Double flanges on outer ring and single flange on inner ring realize one-way axial locating, limiting shaft displacement in single direction only, allowing minor axial movement in reverse direction. EC optimized rollers improve load distribution and reduce edge stress. Polyamide cage features low self-weight and low friction, suitable for continuous medium-high speed operation.

Important reminder: This bearing only supports one-way axial positioning and cannot bear bidirectional axial loads. In shaft design, use this bearing as fixed end and match NU series floating bearing to absorb thermal elongation of shaft. Continuous operating temperature limit for polyamide cage ≤120℃. Heating by open flame is forbidden; mounting temperature shall not exceed 120℃. Assembly force must not transfer through rollers and cage to avoid cage fracture. Open bearing design relies on housing sealing to prevent dust and moisture entering raceway.

2 Structure & Operating Characteristics

Japan NMT BC1B 320811 single row cylindrical roller bearing adopts classic NJ structure with double outer ring flanges and single inner ring flange, fitted with EC optimized roller assembly. Equipped with loose flange on inner ring and no integrated flange on outer ring. No axial floating capacity; capable of supporting radial loads and unidirectional axial loads.

EC optimized roller geometry disperses contact stress and restrains premature pitting at raceway edges, delivering Explorer grade load capacity and fatigue life. Glass fiber reinforced polyamide cage offers low friction, minor vibration and good temperature control under high speed. Separable inner and outer rings facilitate disassembly and maintenance. Without built-in seals, external housing sealing system is required to maintain clean and lubricated raceway environment.

Standard transmission layout: BC1B 320811 (fixed end, one-way locating) + NU cylindrical roller bearing (floating end for thermal expansion compensation) to form mature two-point main shaft support. Not suitable for operating conditions with frequent bidirectional axial impact loads.

3 Core Performance Advantages

1. EC optimized roller profile balances raceway load distribution, delays fatigue spalling induced by edge stress and realizes Explorer-level load performance.

2. Glass fiber reinforced non-metallic polyamide cage reduces operational friction, achieving lower vibration and noise under medium-high speed.

3. NJ one-way locating structure reliably withstands radial loads and unidirectional axial loads, acting as fixed support to restrict single-side axial shaft movement.

4. CN standard radial clearance with wide universality for most normal-temperature general machinery transmission systems.

5. Separable inner and outer rings simplify disassembly, inspection and assembly inside reducer and motor housings.

6. Full dimensional interchangeability with original BC1B 320811 bearing, cutting spare part procurement cost for equipment.

4 Typical Application Fields

4.1 Industrial Motor Equipment

Fixed main shaft support for small variable frequency motors and asynchronous motors

4.2 Gear Transmission Equipment

Fixed side bearing for small gear reducers and servo reducers

4.3 Fluid Power Equipment

Main shaft support of centrifugal fans, blowers and small air compressors

4.4 Light Industry General Machinery

Transmission shafts of textile machinery, packaging equipment and light belt conveyors

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

Keep assembly workshop clean, free of metal chips and dust. Apply pressing force directly on inner ring end surface; avoid external force on roller and cage assembly. Max heating temperature for mounting is limited to 120℃ to prevent softening and deformation of polyamide cage. Verify axial locating direction after assembly to comply with drawing requirements.

5.2 Selection Guidance

Single-side axial restriction and unidirectional axial force required → BC1B 320811 (equivalent to NJ203ECP)

Bidirectional axial positioning needed on both shaft ends → adopt NH bearing or two sets of NJ bearings arranged opposite

Obvious thermal elongation requiring axial compensation → pair with NU series floating bearing

Continuous operating temperature above 120℃ → select version with solid brass cage

5.3 Lubrication Maintenance Instruction

Compatible with lithium grease and circulating oil lubrication. Conduct low-speed no-load running-in for 2~4 hours before formal operation. Replenish lubricant periodically according to load and rotating speed. Long-term dry friction of rolling surfaces is prohibited. No pre-filled grease supplied; sufficient lubricant must be injected during assembly.

5.4 Environmental Application Notes

Polyamide cage has poor resistance against acid and alkali corrosion. Without factory fitted seals, enhance housing oil seal and end cover sealing under dusty and humid conditions. This model is not recommended if continuous bidirectional axial impact exists.

6 Daily Maintenance & Fault Troubleshooting

Monitor temperature rise, vibration and abnormal noise during running-in. Common failure modes: raceway fatigue spalling, roller edge pitting, cage abrasion & fracture, surface scuffing caused by insufficient lubrication.

Typical failure causes: cage damage from improper assembly force, overheating during mounting, inadequate lubrication, hard foreign particles invading raceway, wrong axial installation direction. Bearings with broken cage or extensive raceway spalling cannot be repaired and need immediate replacement.