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lager size slewing bearing wholesale

Large-Diameter Slewing Bearings for OEM and Replacement Projects

SWBTEC supplies slewing bearings for batch purchasing, equipment production, and replacement projects. Select from ball and roller raceway designs with internal gear, external gear, or gearless configurations, then define the final bearing by its load case, mounting interface, motion cycle, and operating environment.

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Cutaway view of a double-row ball slewing bearing with internal gear teeth

Define the Bearing by Dimensions, Not by “Large”

“Large” has no universal diameter threshold across slewing bearing manufacturers. Define the required bearing with the inner diameter, outer diameter, overall height, raceway center diameter, mass, mounting envelope, and transport limits. For an externally geared bearing, use the gear tip diameter when checking the maximum equipment envelope.

SWBTEC product data covers internally geared QN series with nominal catalog designations from 315 to 2000, and externally geared QW and gearless QU series from 315 to 2500. Three-row roller catalog designations run from 500 to 2500. These designation ranges help identify a starting family; the approved drawing controls the finished dimensions, holes, gear geometry, rotating ring, lubrication points, and acceptance values.

Diameter alone does not determine capacity. Ring section, rolling elements, raceway geometry, material, bolt connection, gear load, and the stiffness of the supporting structure all affect the usable load range. Large thin-section rings also require suitable support during shipping, lifting, and installation to limit distortion.

Compare Bearing Families

Choose the Raceway and Gear Arrangement

The raceway structure determines how axial load, radial load, overturning moment, stiffness, precision, and available space are balanced.

Structure When it moves ahead Selection effect and tradeoff
Single-row four-point contact ball A compact combined-load arrangement is the main constraint and the application load point remains inside the selected model’s allowable region Keeps the section compact; a higher radial-load share or overturning demand can move the application toward a roller or multi-row design
Double-row ball A single-row ball design lacks capacity at the available diameter and the machine can accept more axial height and mass Adds load-carrying capability at the cost of a larger section and more demanding load distribution between the rows
Crossed roller Overturning stiffness, rotational accuracy, or a compact roller section controls the decision Alternating rollers support combined loads and stiffness; tighter clearance or preload increases sensitivity to mounting error, friction, and temperature
Three-row roller Combined loads are high and the surrounding structure can keep a large ring sufficiently rigid and flat Separate roller rows can carry different load directions; the larger structure raises mass, transport, installation, and support-stiffness demands

Choose the drive interface separately. An external gear favors outside pinion access when the machine has room for the larger gear-tip envelope. An internal gear can reduce the outer envelope and place the mesh inside the ring, but it consumes center space and changes service access. A gearless bearing fits equipment that provides another drive or positioning method, which shifts gear design and torque-transfer responsibility to that external system.

Discuss the Bearing Structure

Slewing Bearing Options for Wholesale Projects

Review the specified product options by structure, application, and available product-page information. Final selection remains tied to the approved drawing and application load case.

High precision crossed roller slewing bearing with mounting holes

High Precision Cross Roller Slewing Bearing

Crossed rollers provide a compact load path for axial, radial, and moment loads. Listed CRB/CRBC models cover 40–800 mm inner diameters, 65–1,030 mm outer diameters, and 10–150 mm widths. The high-precision offering lists axial/radial runout down to ≤0.005 mm; confirm the series, mounting condition, and inspection method on the approved drawing.

  • StructureCrossed roller
  • Roller materialGCr15SiMn
  • Listed bore range40–800 mm
  • Listed OD range65–1,030 mm
  • Listed width range10–150 mm
  • PrecisionPer model and approved drawing
Request a High Precision Cross Roller Slewing Bearing QuoteProduct details
Forest equipment slewing bearing for a log loader or harvester rotation joint

Forest Equipment Slewing Bearing

This replacement-focused range serves log loaders, harvesters, and related forestry equipment operating with impact, contamination, and outdoor exposure. The product page specifies tempered 42CrMo material, precision heat treatment and grinding, and controlled axial/radial clearance. Match the machine model, serial number, original part number, and interface drawing.

  • Ring materialTempered 42CrMo
  • ClearanceControlled axial/radial clearance
  • UseForestry equipment replacement
  • Matching basisMachine model, serial and part number
Request a Forest Equipment Slewing Bearing QuoteProduct details
Large crane slewing bearing with external gear and mounting holes

Crane Slewing Bearing

Crane slewing bearings connect the rotating upper structure to the supporting structure while carrying combined axial force, radial force, and overturning moment. The product page specifies tempered 40CrMo material, precision grinding, and controlled axial/radial clearance. Final selection uses bearing-interface load combinations and machine identification, not crane lifting capacity alone.

  • Ring materialTempered 40CrMo
  • InterfacesPrecision-ground
  • ClearanceControlled axial/radial clearance
  • Matching basisCrawler- or tower-crane model and loads
Request a Crane Slewing Bearing QuoteProduct details

How Operating Conditions Change the Bearing Choice

The load mix determines which structure carries the application efficiently. Rising overturning moment increases the load difference around the raceway and the demand on the bolt circle. A larger radial-load share changes rolling-element contact and can rule out a compact ball design that otherwise passes an axial-load check. Shock, reversal, and emergency-stop loads also raise local raceway, bolt, and gear demand beyond the normal operating case.

Motion determines whether static capacity or repeated-cycle behavior controls the design. Continuous rotation increases the importance of dynamic life, friction heat, and lubricant behavior. Frequent starts and reversals increase gear and connection loads. Small-angle oscillation repeatedly loads a limited raceway zone, so wear protection and lubricant distribution can become more important than nominal speed.

The supporting structure changes how the calculated loads reach the bearing. A flexible or uneven mounting surface can distort a large ring, concentrate rolling-element load, alter gear contact, and reduce the value of tighter bearing tolerances. A high-stiffness bearing therefore needs a mounting structure and bolt connection capable of preserving its geometry under load.

The operating environment changes both configuration and maintenance. Dust, mud, and water increase sealing and relubrication demands; more aggressive sealing can also increase drag. Temperature differences change lubricant viscosity, seal behavior, and internal clearance. Corrosive exposure can require material or surface-protection changes and shorter inspection intervals.

Review Selection Effects

Manufacturing and Inspection for Large Rings

SWBTEC checks incoming forgings for appearance and dimensions, then rough-machines the rings and uses ultrasonic inspection after rough turning to identify internal discontinuities such as pores, inclusions, and laminations. When specified for the product, quench-and-temper treatment is followed by an overall hardness check.

Raceways are finish-turned with allowance for machining and heat-treatment distortion, induction hardened to a specified HRC 55–62 range, and tempered for stability. Hardness, hardened-layer depth, and cracks are checked after raceway heat treatment. Gear teeth are produced by shaping, hobbing, or milling according to the geometry; high-precision teeth can be ground. Holes, wall thickness, chord dimensions, and precision threads are checked during machining.

Precision grinding controls ring ovality, wall thickness, and flatness before assembly. After the rolling elements, separators or cage, seals, and accessories are installed, the bearing is rotated to check smooth movement and abnormal noise. Finished-bearing inspection can record overall height, axial and radial clearance, axial and radial runout of both rings, mounting-hole geometry, raceway hardness, and applicable gear measurements.

Place the required report fields in the purchase specification. Each inspection record should identify the model, serial number or batch, drawing revision, measured characteristic, acceptance limit, and result so the delivered evidence matches the ordered configuration.

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Build a Comparable Wholesale Quote

Two unit prices are comparable only when they cover the same product boundary. A bearing alone, a bearing with pinion and bolts, and a drive assembly with motor or brake are different deliverables even when the descriptions use the same nominal size. Engineering, tooling, or sample costs may also appear as one-time charges or be distributed across the unit price.

The technical state must also match. Changes in ring structure, material, heat treatment, gear geometry, clearance or preload, seals, precision, and drawing revision can change both manufacturing cost and application behavior. A quotation for a similar catalog designation is not equivalent to a quotation against the approved project drawing.

Inspection and document scope create another boundary. Routine final inspection, recorded measured values, material documents, additional performance testing, and third-party witness points require different work. The purchase specification should identify which evidence is included so a low price is not created by removing required verification.

Commercial and logistics terms complete the comparison. Quantity breaks, one-time charges, warranty scope, Incoterm, packaging, freight, and taxes can shift cost between line items or between buyer and seller. Packaging is selected according to transport distance, storage duration, and destination conditions; large rings may also need orientation and support controls to limit distortion.

SWBTEC accepts small trial orders, with MOQ negotiated by product type. For planning, SWBTEC lists 15–30 days as a typical lead time for standard models; custom-product timing varies with the specification. The current quotation should identify the exact revision, quantity, and committed ship date.

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Frequently Asked Questions

Are two slewing bearings interchangeable if they have the same outside diameter?

Not necessarily. Hole pattern, locating surfaces, mounting height, rotating ring, gear position and geometry, clearance or preload, seals, soft-zone position, and load capacity can differ at the same outside diameter. Interchangeability requires the complete product number, drawing revision, and application requirements to match.

Does reducing clearance always improve rotational precision?

No. Lower clearance or added preload can improve stiffness under the intended mounting condition, but it also raises friction torque and heat and leaves less tolerance for mounting error, structural deformation, and temperature change. Precision, preload, mounting geometry, and operating temperature must be evaluated together.

Can a 3D CAD model control manufacturing and acceptance?

A 3D model is useful for envelope and interference checks. The approved 2D drawing and technical specification should control dimensions, datums, material, heat treatment, gear data, inspection methods, and acceptance limits. SWBTEC can provide 2D drawings, 3D CAD models, and technical documents for design and selection work.

Can a large slewing ring be split into segments for transport?

A segmented design can be evaluated when an integral ring exceeds manufacturing or transport limits. The segment joints, on-site assembly, restored geometry, load path, sealing, and post-assembly inspection then become part of a dedicated design rather than a packaging change.

Which changes require a new review after a sample is approved?

Changes to material, heat treatment, rolling elements, cage or separators, seals, gear geometry, clearance or preload, key dimensions, or controlled processes can affect the approved result. The order should define change notification and identify which changes require recalculation, retesting, or a new first-article approval.

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