Product Introduction

231 series are medium‑width double‑row Spherical Roller Bearings for large bore sizes, the most widely‑used main‑stream series for large‑shaft‑diameter applications. Spherical outer‑ring raceway together with double‑row barrel‑shaped rollers provides 1.0‑1.5° self‑aligning capacity to compensate misalignment caused by shaft deflection and housing deformation. 

It delivers high radial load capacity, considerable bidirectional axial load and good shock resistance, with speed performance between 230 and 232 series. Straight‑bore and 1:12 tapered‑bore K types are available; most sizes are fitted with W33 outer‑ring grease groove and holes. Main precision grades are P0 and P6. Balancing mounting dimension, load capacity and speed, it is widely adopted in various large‑scale heavy‑duty machinery.

Brief comparison: 230 narrow‑section with small outer diameter yet lower load; 231 medium‑width with well‑balanced load and dimension; 232 widened‑section for higher load; 239 ultra‑narrow section with limited load capacity. Suitable for large‑shaft‑diameter equipment requiring high load under limited radial installation space.

Specifications

Bore range:110‑720mm (model range 23122‑231/720). Compared with 230 at identical bore, load capacity rises by 20‑30%, outer diameter and width increase while limiting speed drops 9‑16%.

Reference Model:23144CA/W33

‑ Bore d:220mm

‑ Outer diameter D:370mm

‑ Width B:120mm

‑ Basic dynamic load Cr:1120kN

‑ Basic static load Cor:1430kN

‑ Limiting speed(grease):1100r/min

‑ Limiting speed(oil):1400r/min

Withdrawal sleeves are preferred for large‑bore tapered‑bore bearings. Keep monitoring clearance reduction during assembly to avoid over‑preload.

Material, Model & Suffix Explanation

Inner / outer rings and rolling elements adopt vacuum‑degassed GCr15 bearing steel; electroslag‑remelted steel for extra‑large sizes. Quenched‑tempered hardness HRC 58‑62.

Cage types:

‑ CA: solid brass cage, standard for large sizes, suitable for shock and fluctuating‑load conditions;

‑ CC: stamped steel cage, rarely used for large‑bore sizes;

‑ E/E1: optimized roller profile for higher load rating.

Common suffixes

‑ K: 1:12 tapered bore;

‑ W33: outer‑ring grease groove & holes for on‑site re‑lubrication;

‑ C2/C3/C4: radial clearance; C3 for general use, C4 for shock‑vibration.

Typical model: 23144CAK/W33C3: 231 series, solid brass cage, tapered bore, W33 grease groove, C3 clearance.

Manufacturing Process

1. Ultrasonic raw‑material inspection to detect inclusion and porosity defects of large forgings;

2. Hot die forging for continuous metal flow‑lines on raceway;

3. Staged controlled quenching‑tempering to control ovality and warpage of large rings;

4. Turning to strictly control geometric tolerance of ribs and raceways with uniform grinding allowance;

5. Superfinishing for rollers and raceways to optimize contact profile and reduce contact stress;

6. High‑precision clearance grouping‑matching and thorough deburring for W33 grease groove;

7. Finished‑product non‑destructive test, dimension / clearance / vibration inspection, multi‑point‑support cleaning and anti‑rust packaging.

Application Scenarios

Heavy‑duty machinery with large shaft diameter, moderate radial space, heavy load, acceptable shock and moderate speed requirement.

‑ Metallurgy: mill back‑up rolls, table Roller Bearings

‑ Building materials: medium‑large rotary kilns, dryers

‑ Paper‑making: large dryer cylinders

‑ General heavy machinery: large rotary drums, heavy‑duty gearboxes, crushers

 W33 version for equipment requiring periodic on‑site re‑lubrication; upgrade to 232 for higher load capacity; select C4 clearance under shock‑vibration.

Installation Guidelines

1. Max heating temperature for thermal mounting ≤110 ℃. Ensure uniform heating for large rings. Open‑flame heating is forbidden. Strike only bearing end faces.

2. When assembling tapered‑bore bearing with withdrawal sleeve, tighten step‑by‑step in multiple passes and re‑measure radial clearance after each tightening.

3. Select proper interference; avoid excessive assembly stress for large‑size bearings.

4. Precisely align W33 grease groove with housing lubrication channels.

5. Manually rotate shaft after assembly to confirm smooth rotation. Perform no‑load running‑in; full‑load operation is permitted only after normal temperature rise is verified.

After‑sales Maintenance

1. Lubrication: adopt heavy‑duty extreme‑pressure lithium grease, fill 1/3‑2/3 of bearing cavity. Re‑grease periodically to expel aged grease. Over‑filling which causes overheating is prohibited.

2. Inspection: temperature rise shall not exceed 40 ℃ above ambient temperature. Shut‑down for troubleshooting once abnormal noise or sharp temperature rise occurs.

3. Storage: large‑size bearings must be stored horizontally with multi‑point support. Vertical storage is forbidden. Keep moisture‑proof and rust‑proof.

4. Failure diagnosis: raceway spalling induced by overload; rib wear caused by excessive axial force; abrasive wear from seal failure; cage damage resulting from improper mounting.

Selection Notes

231 is the well‑balanced series for large‑bore Spherical Roller Bearings. Choose 230 for smaller outer diameter; choose 232 for higher load rating. Add thrust bearings when axial load is heavy. Enhance sealing under dusty and humid harsh conditions.