Product Introduction

239 Series Spherical Roller Bearings are ultra‑large‑bore ultra‑narrow‑section double‑row spherical Roller Bearings, mainly for applications with very large shaft diameter and strict radial‑size constraints. Spherical outer‑ring raceway and double‑row barrel‑shaped rollers provide 1.0‑1.5° self‑aligning ability to compensate shaft deflection and assembly misalignment. This series features very small section height, medium radial load capacity, limited axial load and average shock resistance, yet achieves smallest outer‑diameter and good speed rating under identical bore. 

Straight‑bore and 1:12 tapered‑bore K types are available; most large sizes are equipped with W33 grease groove and holes. Precision grades P0 and P6. Widely used in large rotary machinery with extremely limited housing radial space and non‑extreme heavy‑load conditions.

Brief comparison: 239 ultra‑narrow‑section with smallest outer diameter and lowest load capacity; 230 narrow‑section; 231 medium‑width; 232 widened heavy‑duty. Preferred for large‑shaft‑diameter equipment requiring minimized bearing outer diameter under moderate load.

Specifications

Bore range:220‑850mm (model range 23944‑239/850). Compared with 230 of same bore, outer diameter is smaller, basic load rating drops by 22‑35%, limiting speed rises 12‑22%.

Reference Model:23952CA/W33

‑ Bore d:260mm

‑ Outer diameter D:360mm

‑ Width B:75mm

‑ Basic dynamic load Cr:465kN

‑ Basic static load Cor:662kN

‑ Limiting speed(grease):1200r/min

‑ Limiting speed(oil):1500r/min

Withdrawal sleeves are generally adopted for ultra‑large‑bore tapered‑bore bearings. Strictly control clearance to avoid over‑preload overheating.

Material, Model & Suffix Explanation

Inner / outer rings and rolling elements: electroslag‑remelted or vacuum‑degassed GCr15 bearing steel, quenched‑tempered hardness HRC 58‑62.

Cage:

‑ CA solid brass cage, standard for ultra‑large sizes;

‑ CC stamped‑steel cage is barely applicable for this series;

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

Suffixes

‑ K:1:12 tapered bore;

‑ W33: outer‑ring grease groove & holes;

‑ C2/C3/C4 radial clearance; C3 general‑purpose, C4 for shock‑load.

Typical model: 23952CAK/W33C3:239 series, solid brass cage, tapered bore, W33 grease groove, C3 clearance.

Manufacturing Process

1. Ultrasonic raw‑material inspection for internal defects of ultra‑large forgings;

2. Hot die forging, ensure complete raceway metal flow‑lines for ultra‑narrow section;

3. Controlled quenching‑tempering to restrain heat‑treatment distortion of thin rings;

4. Turning with strict geometric‑tolerance control;

5. Superfinishing of rollers and raceways for optimized contact profile;

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

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

Application Scenarios

Large rotary equipment with ultra‑large shaft diameter, extremely limited housing radial space, moderate load and certain speed requirement.

‑ Metallurgy: large furnace rotary supports

‑ Construction machinery: auxiliary bearings for large slewing structures

‑ Building‑material: light‑duty large rotary drums

‑ General heavy machinery: large low‑speed rotary mechanisms

W33 for re‑lubrication maintenance; upgrade to 230 for higher load capacity; select C4 clearance under shock‑vibration.

Installation Guidelines

1. Max thermal‑mount heating ≤110 ℃, ensure uniform ring temperature. Open‑flame forbidden. Strike only bearing end faces.

2. Tighten withdrawal sleeve step‑by‑step in multiple passes for tapered‑bore bearings, re‑measure clearance after each pass.

3. Select reasonable interference; ultra‑narrow‑section rings have relatively weak rigidity, avoid excessive assembly stress.

4. Align W33 grease groove with housing lubrication passages.

5. Manually rotate shaft after assembly, perform no‑load running‑in and confirm normal temperature rise before full‑load operation.

After‑sales Maintenance

1. Lubrication: extreme‑pressure lithium grease, fill cavity 1/3‑2/3. Periodically re‑grease to expel aged grease, over‑filling is not allowed.

2. Inspection: temperature rise ≤+40 ℃ above ambient. Shut‑down immediately upon abnormal noise or sharp temperature rise.

3. Storage: ultra‑large bearings stored horizontally with multi‑point support, vertical storage strictly forbidden. Keep moisture‑proof and rust‑proof.

4. Failure modes: raceway spalling caused by overload; rib wear under excessive axial force; abrasive wear due to seal failure; ring deformation from excessive assembly stress.

Selection Notes

Core advantage of 239: minimum outer‑diameter at given bore for radial‑space saving. Load capacity is relatively weak; do not select for heavy‑duty conditions. Upgrade to 230 / 231 for higher load. Install additional thrust bearings for heavy axial load. Apply reliable sealing protection.