Withdrawal Sleeves
Product Overview
Withdrawal sleeves are tapered steel sleeves used to mount bearings with a tapered bore onto cylindrical shafts without requiring seating shoulders. The sleeve is split axially along one side and features an external taper matching the bearing bore.
Mechanical and hydraulic mounting methods push the bearing onto the sleeve or draw the sleeve into the bearing bore. This radial interference fit secures the bearing reliably under high axial and radial loads, preventing relative movement (creeping) between the shaft and the inner ring.
Product Range
The AH series covers metric dimensions designed to ISO standards, categorized by dimension series and thread pitches:
AH2 Series
Standard profile for general industrial gearboxes and heavy machinery; suitable for standard shaft diameters.
AH22 Series
Narrower profile designed for compact spaces and shorter shaft seating lengths.
AH23 Series
Heavier cross-section series capable of higher radial preloads for severe-duty applications.
AH30 Series
Thin-walled, large-diameter series utilized in rolling mills, wind energy main shafts, and large industrial fans.
AH31 Series
Moderate-width, large-bore series optimized for heavy conveyor drives and paper machinery.
AH32 Series
Extra-wide series engineered for maximum load distribution in high-vibration environments.
Material Composition: Forged carbon-chromium steel (equivalent to SAE 52100 or DIN 100Cr6) or high-grade structural alloy steel, heat-treated to achieve a core hardness of 35-45 HRC with a hardened thread zone.
Dimensional Tolerances: Manufactured to ISO 2982-1 specifications. Taper angle tolerance restricted to AT5; thread pitch diameter tolerance restricted to class 6g.
Surface Finish: External taper ground to Ra <= 0.8 um to minimize friction during mounting and dismounting. Anti-corrosion protective oil coating applied.
Hydraulic Assist Integration: Sleeves sized >= 200 mm bore diameter feature oil supply ducts and distribution grooves on both the tapered outer surface and the bore to facilitate hydraulic oil injection, reducing mounting force by up to 80%.
Key Specifications
|
Series |
Bore Range (mm) |
Thread Size Range |
Typical Application Industry |
Hydraulic Channels |
|
AH2 |
20 - 1000 |
M25x1.5 - TR200x4 |
Gearboxes, Electric Motors |
Available >= size 40 |
|
AH22 |
45 - 1000 |
M55x2 - TR200x4 |
Compact Drives, Pumps |
Available >= size 40 |
|
AH23 |
35 - 1000 |
M45x1.5 - TR200x4 |
Crushers, Mining Equipment |
Available >= size 40 |
|
AH30 |
100 - 1250 |
TR100x2 - TR1000x8 |
Rolling Mills, Wind Turbines |
Standard on all sizes |
|
AH31 |
100 - 1000 |
TR100x2 - TR800x7 |
Paper Machinery, Marine Drives |
Standard on all sizes |
|
AH32 |
100 - 1000 |
TR100x2 - TR800x7 |
Heavy Industrial Fans, Pulverizers |
Standard on all sizes |
How to Select Withdrawal Sleeves
Match Bearing Bore and Series: Identify the exact bearing designation (e.g., 22220EK) to determine the required sleeve series (AH220) and shaft size.
Verify Shaft Diameter Tolerance: Standard sleeves require h9 to h11 shaft tolerances. High-precision or high-speed applications require h8 tolerances to prevent shaft fretting.
Determine Mounting Method: Specify standard locknut tightening for bores < 200 mm; specify hydraulic nut (HM series) or oil injection ports for bores >= 200 mm.
Assess Load and Thermal Conditions: Review application load ratings. High shock loads require checking the residual radial internal clearance after mounting to prevent bearing binding.
Applications
Mining & Mineral Processing
Jaw crushers, vibrating screens, and conveyor pulley drives subject to heavy shock loads.
01
Pulp & Paper
Dryer section rolls, refiners, and calendar stacks operating under continuous moisture and thermal gradients.
02
Power Generation
Wind turbine generator gearboxes and coal pulverizer drives requiring high fatigue resistance.
03
Marine & Offshore
Thruster gearboxes, steering gear assemblies, and stern tube bearings.
04
Cleanliness: Remove all preservative oils from the shaft seating and sleeve bore using a residue-free solvent. Apply a thin layer of light mounting oil to the sleeve taper and bearing bore. Do not use anti-seize compounds containing molybdenum disulfide (MoS2), as they reduce friction too significantly and risk over-expansion of the inner ring.
Axial Drive-Up Measurement: Measure the exact initial clearance of the bearing before mounting. Use feeler gauges or dial indicators to track the axial drive-up distance specified in engineering data sheets.
Hydraulic Injection Pressure: Connect the hydraulic pump to the sleeve nipple. Inject oil until a stable oil film forms between the mating surfaces before applying axial drive-up force via a hydraulic nut. Release oil pressure only after the locknut is fully torqued.
Inspection & Quality Control
Raw Material Testing
Spectrometric chemical composition analysis and ultrasonic testing of forged steel bars to detect internal inclusions or micro-cracks.
Dimensional Metrology
100% inspection of thread pitch diameter, wall thickness, and axial slot parallelism using air gauges and coordinate measuring machines (CMM).
Taper Angle Verification
Air-gauge master ring inspection to verify 1:12 or 1:30 taper accuracy against ISO reference standards.
Traceability
Laser-etched heat code and batch number on the face of each sleeve linked to raw material mill test certificates (EN 10204 3.1).
Supply & Customization Options
Standard Inventory: Comprehensive stock of metric dimensions (AH2 through AH32 series) in carbon-chromium steel, ready for immediate dispatch.
Custom Engineering:
Special thread pitches (UN/UNF threads or custom metric leads).
Non-standard sleeve lengths to fit customized bearing housings or adapter geometries.
Specialized corrosion-resistant coatings (phosphate coating, zinc-nickel plating, or stainless steel alloys for marine environments).
Packaging: Industrial bulk packaging or individual rust-inhibitor poly bags packed in reinforced wooden crates to prevent transit damage.
What Buyers Should Provide
To generate an accurate technical proposal and commercial quotation, please provide:
Complete Part Designation: Exact withdrawal sleeve part number (e.g., AH3130) or matching bearing model number.
Quantity Required: Annual volume or per-shipment batch size.
Material Specifications: Standard carbon steel or specific corrosion-resistant requirements.
Target Destination: Delivery port or warehouse zip code for freight calculation.
Documentation Requirements: Certificate of Origin, Material Test Certificates (EN 10204 3.1), or third-party inspection reports.
FAQ
Q: Can withdrawal sleeves be reused during bearing replacement?
A: As a general rule, withdrawal sleeves should be replaced whenever a bearing is changed. Disassembly often induces minor elastic deformation, scoring, or thread wear, which compromises the interference fit and seating accuracy of a new bearing.
Q: What is the difference between an adapter sleeve and a withdrawal sleeve?
A: Adapter sleeves feature an external taper and are used to mount bearings with a tapered bore onto cylindrical shafts using a locknut. Withdrawal sleeves feature an external taper matching a tapered-bore bearing, but they are pushed into place or removed using axial extraction threads and hydraulic assist.
Q: How do I select between an AH series and an AHX series sleeve?
A: The designation difference typically denotes thread pitch or specific regional standard variations (e.g., metric vs. inch dimensions or specific thread leads). Check the exact shaft thread specification of your existing assembly to ensure thread engagement compatibility.
Q: Why is oil injection necessary for sleeves over 200 mm bore?
A: Large-bore sleeves require substantial frictional force to mount. Hydraulic oil injected between the mating surfaces separates the steel interfaces, reducing friction by up to 80% and preventing galling or scoring of the shaft and bearing bore.
Q: What shaft tolerance is recommended for heavy radial loads?
A: For heavy loads and high vibration, an ISO h8 or h9 shaft tolerance is recommended. Softer tolerances (h10/h11) may be acceptable for light, constant loads where axial positioning slip is not a risk.
Q: What standard certificates are provided with shipments?
A: Standard shipments include an inspection report and EN 10204 3.1 Material Test Certificates. Third-party inspections (SGS, TÜV) can be arranged prior to dispatch upon request.
RFQ
Submit Technical Inquiries: Send drawings, part lists, or annual demand forecasts to our engineering sales desk.
Response Commitment: Technical review and commercial quotation provided within 24 business hours.
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