Calculate the Thermal Range Between Your Shaft and Housing
Our thermal range calculator helps engineers see how the material of the bearing, housing and shaft will grow or shrink when in operation.
The top section is based off installation temperatures and ABEC / DIN / ISO standards. The lower section applies the temperature input and calculates how the materials will attempt to grow or shrink.
Note that this information is provided within the free state of the materials. There will be some variation from the below due to resistance between the materials; this should be under consideration.
For standard applications where accurate specs aren’t known, the ambient room temperature where the spindle is used can be used for the housing temperature field. Add an additional 10°C for the shaft temperature. This 10°C increase for shaft temperature will usually provide a good estimate for the increased running temperatures.
Note: High n*dm applications and high load applications may produce more than a 10°C difference between the shaft and housing temperature.
Make sure to check out our shaft and housing tolerance calculator to ensure you get the right tolerance when machining your shaft and housing.
General Application Notes for Precision Bearings
1. The ID of the Bearing should rarely float on the shaft. A line fit is an ideal minimum for many applications to prevent inner race slipping.
2. The OD of the Bearing should usually have a slight gap during install. This gap will ensure space for heat and centrifugal force expansion.
3. The generic suggested nominal install tolerances are a ~3 micron press fit on the ID and a ~4 micron gap on the OD. This is an “ideal” world and can be expensive/difficult to machine. These values should be adjusted for bearing size, speed, temperature, and other possible application specifics.
4. A positive resultant number above implies a GAP where a negative number implies INTERFERENCE.
5. For standard applications where more accurate specifications are not known, the ambient temperature of the room where the spindle is used can be utilized for the Housing temperature and an additional 10°C increase can be used as the Shaft temperature. This 10°C rise in shaft temperature will generally make up for increased running temperatures. High n*dm applications and high load applications may have a higher temperature delta between the shaft and housing.
6. There are many factors that go into proper tolerancing; bearing size, RPM, temperature, materials, duty cycle, etc. All can play a role in proper tolerancing. This page is designed to be a guide for general applications. GMN Bearing USA Ltd. and its partners make no representations or warranties of any kind regarding the tool and information contained on this page. Any use or reliance upon this tool and information shall be at the sole risk of the user and GMN Bearing USA Ltd. shall have no liability whatsoever with respect to any decisions or actions made by the user based on results obtained from this tool and information.
DISCLAIMER: The data provided on this page is for general information purposes only. While the intention is to provide accurate information, the calculations performed by these tools/calculators are mathematical estimates only and errors may exist in the supplied information. There is NO WARRANTY OR GUARANTY, expressed or implied, regarding the accuracy of this information or its applicability to your engineering situation. Please consult your own engineering consultant before making any technical decisions.