1 Complete Model & Code Explanation

Model：HJ 205 EC

Code Definition

HJ：Angle ring (L-shaped thrust collar) series for cylindrical roller bearings

205：Size segment matching NU/NJ 205 series cylindrical roller bearings

EC：Compatible with EC optimized roller bearing design

Structure：L-shaped stepped locating thrust collar, independent component, not a complete rolling bearing

Supply form：Separate single component, pre-assembled bearing not included; to be combined with NU205EC / NJ205EC on demand

Important reminder: HJ 205 EC is bearing accessory locating angle ring instead of complete bearing, cannot bear independent radial rolling load. It must be installed matched with corresponding cylindrical roller bearing for axial limitation. Ensure flat contact of end faces during assembly; avoid striking the edge to prevent impact damage. High hardness with relative brittleness; violent heating or forced pressing is prohibited. Only compatible with NU205EC and NJ205EC; mixing with other bearing series is forbidden.

Basic Parameters

Bore d：25 mm

Outer diameter d₁：34.7 mm

Width contacting inner ring B₁：3 mm

Overall width B₂：6 mm

Minimum radial chamfer r₃,₄：0.6 mm

Material：High carbon chromium bearing steel

Surface finish：Hardened precision ground, uncoated

Net weight：0.015 kg

Indicative carbon footprint：0.05 kg CO₂e

eClass code：23-05-09-01

UNSPSC code：31171505

Combination Matching

HJ205EC + NU205EC = NH205EC (cylindrical roller bearing with bidirectional axial locating function)

HJ205EC + NJ205EC: Reinforce bidirectional axial load limitation

2 Structure & Operating Characteristics

Japan NMT HJ 205 EC adopts L-shaped stepped profile with overall quenching and double-sided precision grinding, strictly controlled flatness and dimensional tolerance in accordance with international standards. Mounted inside NU-type unflanged cylindrical roller bearing to provide unidirectional axial support for shaft system; two sets arranged oppositely achieve bidirectional positioning and restrict axial shaft movement during operation.

This component only undertakes axial limiting load, while radial load is fully borne by matched cylindrical roller bearing. Suitable for medium-high speed and moderate shock conditions with low friction loss and stable temperature rise. The shaft shoulder, angle ring and bearing inner ring must fit tightly after installation; excessive clearance leads to concentrated local stress and end surface abrasion. Not recommended for compact structures suffering severe alternating axial impact without sufficient installation space.

3 Core Performance Advantages

1. Integrally quenched high carbon chromium bearing steel with uniform hardness, excellent resistance to end crushing and abrasion.

2. Double-sided precision grinding ensures superior end face parallelism, tight assembly contact and avoids uneven load wear.

3. Standard universal dimension, perfectly compatible with NU205EC and NJ205EC, direct replacement for imported equivalent angle rings.

4. Reliable positioning by L-step design, quickly convert free-floating NU bearing into axially fixed NH bearing unit.

5. Stable dimensional consistency and good interchangeability for mass automatic assembly production lines.

6. Supplied as independent spare part, flexible bearing scheme matching and lower machine design & spare part procurement cost.

4 Typical Application Fields

4.1 Industrial Drive Motors

Main shafts of large & medium three-phase asynchronous motors, rotor supporting structures of variable frequency motors.

4.2 Gear Reduction Drives

Axial positioning components inside industrial gearboxes and planetary reducers.

4.3 Machine Tool Equipment

Auxiliary support for spindle of lathes and machining centers, feed transmission mechanisms.

4.4 Construction Machinery & General Equipment

Air compressors, internal combustion engines, vibratory conveying equipment, transmission systems of light lifting machinery.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

Keep assembly surface clean and burr-free. Apply pressing force evenly on flat end surface of angle ring. Impact on L-shaped step corner is forbidden to prevent edge chipping and surface indentation. Shaft shoulder roughness and perpendicularity must meet specification; check no warping or clearance after mounting. No sealing structure on angle ring; equip machine housing protection for dusty working conditions.

5.2 Selection Guidance

Axial positioning required, using floating NU205EC bearing → match with HJ 205 EC to form NH locating bearing

NJ205EC in service, need strengthened bidirectional axial limitation → install HJ 205 EC on single or double sides

Bearing model outside 205EC series → cross-series mixing prohibited

5.3 Maintenance Instruction

No independent lubrication required for angle ring; friction protection relies on grease inside matched bearing. Regularly inspect shaft end axial play. Obvious increase of axial clearance indicates end surface abrasion of angle ring, disassembly inspection and replacement recommended.

5.4 Environmental Application Notes

No anti-rust coating on angle ring; complete machine sealing and rust prevention required for long-term outdoor and high humidity service. Auxiliary shaft lock nut is suggested under continuous heavy axial shock to avoid instantaneous overload on angle ring.

6 Daily Maintenance & Fault Troubleshooting

Carry out no-load low-speed running-in after assembly, monitor axial play and abnormal noise. Common failure modes: end indentation, local abrasion and edge chipping.

Typical failure causes: uneven assembly force, insufficient machining precision of shaft shoulder, instantaneous axial impact overload, foreign debris trapped on fitting surface causing abrasive wear. Angle rings with chipping or heavy indentation cannot be repaired, replace directly.