Gearbox Bearings: Precision Under Load
Industrial gearboxes transmit high torque through precisely meshed gears. The bearings supporting those gears should be reviewed by shaft position, load direction, speed, lubrication, failed model, suffix, quantity, destination, and document needs before quotation.
Typical Operating Conditions
- Load: High torque, combined radial + axial
- Speed: 100–3600 RPM (varies by stage)
- Lubrication: Oil bath or circulating oil
- Temperature: 60–100°C normal operation
- Precision: Shaft positioning critical for gear mesh
Recommended Bearing Solutions
High-Speed Input Shafts
Cylindrical Roller Bearings (NU series) for the non-locating (floating) position combined with angular contact ball bearings or NJ/NUP cylindrical for the locating position. This arrangement handles high speeds while maintaining precise axial positioning.
Intermediate and Low-Speed Shafts
Spherical Roller Bearings (22200, 22300 series) in locating/non-locating pairs. The self-aligning capability compensates for housing bore misalignment and shaft deflection under load—a common issue in large gearboxes with long shaft spans.
Crane and Hoist Gearboxes
E1 Series Spherical Roller Bearings for the output shaft where shock loads from lifting operations may require high-capacity review. Tapered bore and adapter sleeve details should be included when mounting data is available.
Conveyor Drive Gearboxes
Standard Spherical Roller Bearings (22300 series) for the output shaft where high radial loads from belt tension combine with moderate thrust from helical gearing. Sealed configurations available for dusty conveyor environments.
Bearing Arrangement Best Practices
- Locating/Non-locating: Fix one bearing axially; allow the other to float for thermal expansion
- Clearance: C3 standard for gearbox applications; C4 for high-temperature
- Lubrication: Oil-lubricated bearings must have adequate oil flow for cooling
- Mounting: Tapered bore with hydraulic assist for large bore bearings
RFQ Details Buyers Should Send
Send the equipment type, bearing position, failed model, suffix, load condition, contamination level, lubrication method, quantity, destination, downtime target, and document needs for application-specific review.
| RFQ detail | Example | Why it matters |
|---|---|---|
| application equipment | crusher, vibrating screen, fan, gearbox, conveyor pulley, paper machine, or steel mill position | Application context affects load, shock, speed, contamination, lubrication, and document review. |
| bearing position | drive side, non-drive side, screen exciter, crusher pitman, fan shaft, gearbox input shaft | Bearing position helps review load direction, vibration exposure, access for lubrication, and failure risk. |
| failed model | Photo of old bearing marking, OEM manual reference, or removed bearing code | The failed model helps compare original specification, suffix, and possible replacement route. |
| full suffix / marking | K, K30, C3, C4, W33, CA, CC, MB, 2RS, or full ring marking photo | Suffixes can change bore type, clearance, cage design, lubrication groove, sealing, and replacement risk. |
| load condition | Heavy radial load, shock load, axial load, reversing load, or unknown with equipment details | Load condition affects series selection, cage preference, and whether high-capacity options should be reviewed. |
| environment | Dust, water, slurry, outdoor exposure, high humidity, cement dust, paper mill moisture | Environment affects sealing, grease, corrosion risk, packing, and maintenance interval review. |
| lubrication method | Grease gun, centralized lubrication, oil bath, oil circulation, W33 groove, or sealed bearing | Lubrication method affects suffix review, housing compatibility, contamination control, and relubrication planning. |
| quantity | 1 large bearing, 2 pcs for maintenance, 50 pcs distributor stock, or annual demand | Quantity affects quote route, packing, production planning, inspection scope, and freight review. |
| destination | Destination country, port, warehouse, distributor address, or project site region | Destination affects export documents, packing method, shipping route, and trade-term review. |
| target timing | Maintenance shutdown date, urgent repair, trial order timing, or normal replenishment schedule | Timing helps separate availability review, production planning, sample validation, and consolidated shipment options. |
| required documents | Inspection report, material certificate, COO, RoHS / REACH statement, packing photos, buyer template | Document requirements must be confirmed before quotation because scope depends on order route and buyer template. |
Request Gearboxes & Reducers Bearing RFQ Review
Send us your equipment specifications and operating conditions. TFL Bearing can review application fit, model risk, current availability, production routes, replacement review boundaries, and document needs before quotation.