Mounting and dismounting bearings, bushings and plain bearings is an axial pressing operation in which interference, alignment, support and controlled force build-up determine whether the operation can be carried out reproducibly and without structural damage.
Both bearings and bushings and plain bearings react directly to point loading, misalignment and local deformation. The press stroke must therefore proceed fully linearly, with constant geometric control. A hydraulic workshop press is suitable when the technical boundary conditions demonstrably fall within the working area of the press.
This page defines when mounting and dismounting fall within this application range – and when they do not.
When is a hydraulic workshop press suitable?
A hydraulic workshop press is suitable when:
- the operation proceeds axially without rotation or impact loading
- the pressing force can be built up in a controlled, gradual and reproducible manner
- force introduction takes place via the correct mounting surface:
- inner ring when mounting on a shaft
- outer ring when mounting in a housing
- full circumferential support for plain bearings and thin-walled bushings
- shaft, housing or seat can be flat, stiff and fully supported
- the interference fit is predictable and falls within a controlled force band
When these conditions are not met, there is an immediate risk of raceway damage, deformation, ovalisation or instability in the initial phase of the press stroke.
Technical considerations
Pressing force & force build-up
The required pressing force is determined by:
- interference (Δd)
- material combination
- contact length
- surface roughness
- tolerance conditioning
Force build-up must:
- proceed step by step to avoid peak loading
- be followed continuously for unexpected increase in resistance (indication of misalignment)
- be transmitted with full surface contact to avoid peak stresses
A misalignment of 0.1–0.2 mm generates an asymmetrical pressure profile that causes permanent raceway damage or deformation — even when the total pressing force lies within normal values.
Interference, alignment & support
Correct interference and support determine the stability of the stroke:
- alignment must be established before force build-up
- loading must be introduced via the correct ring to prevent ring deformation
- plain bearings and bushings require full circumferential support
- housing parts must be carried flat and torsionally stiff
- any lateral load component must be excluded
Ovalisation in thin-walled plain bearings arises in the first millimetres of the press stroke when only part of the edge is supported. The deviation often becomes visible only after mounting.
Structural requirements for the press
A suitable hydraulic workshop press has:
- a welded steel frame with minimal lateral deflection
- linear stroke guidance with constant geometry
- pressing tools that follow the load-bearing surface exactly
- a flat, stable and massive working table
- sufficient mass to dampen impact loading and micro-deformation
Even limited frame flex (<0.5 mm) can tilt components in the initial phase of the stroke. The degree of structural stiffness directly determines the failure probability of the assembly.
What is often underestimated in practice
- loading via the wrong ring
- minimal misalignment that damages raceways
- deformation of thin-walled bushings due to point loading
- housing parts that are insufficiently flat or insufficiently stiff
- force peaks due to overly rapid operation
- variation in interference due to preceding thermal condition
- increased resistance due to corrosion or micro-deformation
These factors determine whether the component remains within functional tolerances and dynamic load capacity after assembly.
Typical operations within this application
- mounting and dismounting of ball bearings and roller bearings
- mounting of bronze, steel and plastic plain bearings
- press-fitting thin-walled bushings into shafts and housings
- press-out operations on worn bearing seats
- rework on bearing seats and housing structures
- series mounting in maintenance and assembly environments
This list describes the operation type; not which specific press is suitable.
Relation to press classes (HD programme)
Classification within the HD programme is determined by diameter, interference, seat stiffness and force profile.
Light-duty press class (20–60 tonnes)
Suitable for:
- smaller components
- low interference
- short contact length
- stable, thick-walled housings
- limited edge loading
Medium-duty press class (80–160 tonnes)
Suitable for:
- typical industrial dimensions
- normal to increased interference
- longer seats
- need for reproducible force build-up
- stable support
Heavy-duty press class (180–500 tonnes)
Suitable for:
- large bearings or bushings
- high interference
- large diameters
- massive housings
- risk of force peaks due to tolerances
The correct press class is determined by assembly condition and force profile — not by pressing force alone.
When is a workshop press not suitable?
A workshop press is not suitable when:
- support of housing or shaft cannot be guaranteed
- loading via the wrong ring is unavoidable
- thermal mounting is necessary
- interference is unknown or highly variable
- rotation or impact loading is part of the operation
- structural damage cannot be ruled out
Further navigation within the site
Based on this application, reference can be made to:
- the relevant press classes within the HD programme
- the available standard models
For operations that fall outside these boundary conditions, reference is made to the engineering and custom-built hydraulic press trajectory, where non-standard geometries, complex interferences and deviating mounting conditions are assessed technically.
Request technical evaluation
When the operation falls within the described technical boundary conditions, a technical evaluation can be requested to position the application within the correct press class of the HD programme.