H31 Series Adapter Sleeves

H31 series adapter sleeves are used to mount large rolling bearings with tapered bores onto cylindrical shafts. The slotted sleeve is driven axially into the bearing bore to produce the required interference fit between the sleeve and shaft. A complete mounting arrangement typically consists of an adapter sleeve, a matching locknut, and a locking device.
The H31 series is mainly used with large spherical roller bearings and other tapered-bore bearings in heavy-duty rotating equipment. Selection should be based on the bearing designation, shaft diameter, bearing bore and required mounting arrangement, rather than shaft diameter alone. 

The H31 sleeve has a longitudinal slot that allows controlled radial contraction as the sleeve is driven into the tapered bearing bore. This produces an interference fit between the sleeve and cylindrical shaft while providing axial positioning of the bearing.
The 1:12 external taper is intended for compatible metric tapered-bore bearings. The exact bearing series and size must be checked against the dimensional specifications for the selected H31 sleeve.
H31 sleeves are available in multiple sizes for large shaft diameters. Common designations include H3120, H3122, H3124, H3126, H3128, H3130, H3134 and larger sizes. The actual available range depends on the applicable dimensional standard and product series. 

The following dimensions illustrate the H31 size range. They are not a substitute for the dimensional drawing of the specific sleeve. 

Exact dimensions, threads and associated locking components should be confirmed from the drawing or dimensional table for the required H31 designation. 

H31 adapter sleeves are designed for bearings with a matching tapered bore. They are commonly used with large spherical roller bearings and may also be suitable for other tapered-bore bearing types when the dimensions and mounting requirements correspond.
The shaft seating surface should be cylindrical and meet the dimensional and surface requirements specified for the bearing arrangement. h9 is commonly used for adapter-sleeve shaft seats, but the appropriate tolerance depends on the bearing, load, speed and operating conditions.
The bearing's internal radial clearance is an important mounting control parameter. During installation, clearance reduction or the specified axial drive-up should be measured according to the bearing manufacturer's mounting procedure. Excessive drive-up can reduce internal clearance too far and affect bearing operating conditions. 

The locking components must match the selected H31 sleeve. Depending on size and design, H31 assemblies may use KM-type or HM-type locknuts together with the appropriate locking washer or locking device.
For purchasing, specify the complete sleeve designation and bearing designation rather than selecting a locknut only from the nominal shaft diameter. This reduces the risk of mismatched threads or locking components. 

For small and medium H31 sizes, installation is generally carried out by tightening the matching locknut and driving the sleeve axially into the bearing bore with suitable mounting tools.

For larger bearings, hydraulic mounting may be used when the sleeve incorporates the required oil-injection ducts and distribution grooves. Hydraulic provisions are size- and design-dependent and should not be assumed to be standard across the complete H31 range.

During mounting:

Clean the shaft, sleeve and bearing mating surfaces.

Position the bearing and adapter sleeve correctly.

Tighten the locknut to drive the sleeve axially into the bearing bore.

Measure bearing internal clearance or axial drive-up as specified by the bearing manufacturer.

Stop mounting when the specified mounting condition is reached.

Secure the locknut with the specified locking device.

The original specification does not provide sufficient product-specific evidence to assign one steel grade, hardness range or surface roughness value to every H31 sleeve. These values should therefore be controlled according to the applicable manufacturing drawing, material specification and customer requirements.
For procurement involving demanding operating environments, the material grade, heat treatment, surface protection and dimensional tolerances should be specified before production. 

Critical inspection items for H31 adapter sleeves include:

• Shaft and bearing interface dimensions
• External taper geometry
• Sleeve length and critical diameters
• Thread dimensions and compatibility
• Slot condition
• Surface condition
• Locknut and locking-device fit

Inspection methods may include calibrated dimensional gauges and other appropriate measuring equipment. Non-destructive testing should only be stated when it is part of the applicable inspection plan or customer specification.

H31 adapter sleeves are used where large tapered-bore bearings must be mounted onto cylindrical shafts. Typical applications include:

• Industrial gearboxes and reducers
• Mining and cement equipment
• Conveyor and material-handling systems
• Paper-making machinery
• Heavy-duty rotating equipment
• Large shaft and bearing assemblies

Application suitability depends on the bearing designation, shaft dimensions, load, rotational speed, mounting method and operating conditions. 

A standard H31 mounting set may include:

• H31 adapter sleeve
• Matching locknut
• Matching locking washer or locking device

The sleeve should be protected against corrosion and mechanical damage during storage and transportation. Packaging requirements can be specified according to shipment conditions and customer requirements.

For quotation and technical confirmation, provide the H31 sleeve designation, bearing designation, shaft diameter, required quantity and any specified material, surface-treatment or inspection requirements.