An unslotted ball bearing disc spring is a conical spring used to apply controlled axial preload to radial ball bearings. Also known as a bearing preload disc spring, it helps reduce axial play, compensate for dimensional tolerances and thermal movement, and maintain stable bearing operation.
Compared with conventional compression springs, disc springs can generate useful axial force within a compact installation space. This makes them particularly suitable for bearing assemblies where installation height is limited and consistent preload is required.
For standard dimensions and load data, see our bearing preload disc springs for ball bearings.
Ball bearings require internal clearance for normal assembly and operation. However, excessive axial clearance can lead to unwanted movement, vibration, running noise and reduced positioning accuracy.
Applying a controlled preload helps maintain contact within the bearing assembly and can:
Reduce axial end play
Improve positioning stability
Minimize vibration and running noise
Compensate for manufacturing tolerances
Accommodate thermal expansion
Maintain more consistent bearing operation
The required preload depends on the bearing design, operating speed, installation space, temperature and application conditions. Too much preload may increase friction and stress, while insufficient preload may fail to control unwanted movement.
A bearing preload disc spring is installed next to the bearing and compressed to a defined working height. As the spring deflects, its conical shape generates an axial force against the bearing race.
In many radial ball bearing arrangements, the spring acts against the outer race. Depending on the shaft, housing and bearing arrangement, some designs may instead apply preload to the inner race.
Because the disc spring can continue to deflect slightly as dimensions change, it can help maintain preload when the assembly is affected by:
Thermal expansion
Manufacturing tolerances
Component wear
Small axial movements
Operating vibration
This combination of controlled force and compact size makes disc springs useful for preload applications in rotating equipment.
Bearing preload disc springs are available in different structural designs. Two common forms are unslotted and slotted springs.
| Design | Unslotted Disc Spring | Slotted Disc Spring |
|---|---|---|
| Structure | Solid conical ring | Conical ring with radial slots |
| Spring behavior | Relatively higher stiffness | Softer spring characteristic |
| Deflection | Generally shorter | Can provide greater deflection |
| Load response | Suitable for stable preload | Suitable where a lower load increase over greater travel is required |
| Typical use | Standard bearing preload arrangements | Bearing assemblies requiring a softer spring response |
An unslotted bearing preload spring is generally selected where compact dimensions, consistent axial force and a simple solid-ring construction are preferred.
A slotted design may be considered when the application requires a larger working deflection with a softer spring characteristic.
Final selection should always be based on the required preload, available installation space and bearing arrangement.
The main purpose of an unslotted ball bearing disc spring is to maintain axial preload in a bearing assembly.
Typical applications can include:
Bearing preload can help control axial movement and maintain stable rotor positioning where compact spring installation is required.
Disc springs can compensate for dimensional variation and maintain axial force on bearings operating under changing loads and temperatures.
Bearing preload springs can help maintain stable positioning while accommodating small dimensional changes during operation.
Controlled preload can support positioning accuracy and reduce unwanted movement in applications where bearing stability is important.
Unslotted disc springs are also used in other radial ball bearing arrangements where axial preload, tolerance compensation and compact installation are required.
The correct spring should be selected according to the actual bearing and machine design rather than the industry alone.
Disc springs can provide axial force within a relatively short installation height, making them suitable for space-limited bearing assemblies.
The spring can maintain an axial force while allowing limited deflection as assembly dimensions change.
Temperature changes can alter shaft, housing and bearing dimensions. A properly selected disc spring can accommodate some of this movement while maintaining preload.
Controlled preload helps reduce unwanted axial movement, which can contribute to improved stability and lower vibration.
The unslotted design provides a continuous conical ring without radial cutouts, making it suitable for many standard bearing preload arrangements.
Selecting a bearing preload spring requires more than matching the outside diameter.
Important parameters include:
Ball bearing model or dimensions
Available spring outside diameter
Required inside diameter
Available installation height
Required axial preload
Working deflection
Operating temperature
Material
Corrosion environment
Expected service cycles
If a standard preload spring is available for the selected bearing size, engineers can compare the dimensional and load data with the required working condition.
HEGONG provides standard bearing preload disc springs with corresponding bearing dimensions and load characteristics. View the ball bearing disc spring size and load table for engineering selection.
A disc spring does not produce the same force throughout its entire travel. Spring force changes as the spring is compressed, so the working position must be considered during selection.
HEGONG's standard ball bearing disc spring data include load values at defined deflection positions, including 50% and 75% of the initial cone height.
These values help engineers compare:
Required bearing preload
Available spring travel
Installed height
Load at the intended working position
The spring should not simply be compressed as far as possible. Excessive deflection can increase stress and reduce fatigue performance.
For applications requiring special load-deflection characteristics, a custom spring may be more appropriate than selecting only by bearing diameter.
If a standard size does not match your bearing assembly, provide the following information for engineering evaluation:
Bearing model or bearing OD/ID
Available spring OD and ID
Free or installed height
Required preload force
Available deflection
Operating temperature
Working environment
Expected cycle life
Quantity
Drawing, if available
Material and surface treatment should also be selected according to the operating environment. You can review our disc spring material selection guide for additional information.
It is a conical spring installed in a ball bearing assembly to apply axial preload and help compensate for clearance, tolerances and dimensional changes.
Their compact conical design allows them to provide axial spring force within limited installation space while accommodating small changes in working height.
An unslotted spring has a continuous solid-ring structure. A slotted spring contains radial slots and can provide a softer spring characteristic and greater deflection for certain bearing arrangements.
In many radial ball bearing assemblies, the spring acts against the outer bearing race. Other arrangements may preload the inner race depending on the shaft and housing design.
Start with the bearing dimensions, required preload, available installation space and working deflection. Temperature, material, environment and service cycles should also be considered.
Yes. Custom disc springs can be developed when standard dimensions or load characteristics do not match the bearing assembly requirements.
If you already know your bearing size and required preload, view HEGONG's bearing preload disc springs for ball bearings for available dimensions and load-deflection data.
For special bearing arrangements, send us your bearing model, available installation dimensions, required preload and operating conditions for engineering evaluation.
Contact HEGONG to discuss your bearing preload requirements.
