If you want to get the most out of your machinery, you must take into consideration the maximum service life of each component. With ball bearings being one of the most common parts used in most machines with moving parts, it's crucial to know what is the best way of mounting a radial ball or roller bearing.
Installation is important as faulty mounting can lead to a decreased service life. This leads to unexpected costs and stop in production.
When using a hammer or even a torch to mount a ball bearing, you're risk causing a major machine failure that can lead to a serious safety hazard.
To successfully mount and install a ball bearing you'll need to accept the fact that investing in education and time initially, will save you regular maintenance costs on the long haul.
Before you start, you make sure the process has been properly delegated and explained among the team that will conduct the installation. It's crucial that everyone understands the reasons behind each step, so you can avoid the usage of shortcuts and make sure you're using the right set of tools.
THINGS TO NEVER DO!
- Never place aluminum parts on hot plates of any kind. It is next to impossible to heat evenly and even harder to control the temperature. Going to 400 F is the max you can go.
- Don't use a torch if you want to keep the housing and other parts undamaged.
- Don't heat up the bearing. It expands and makes the removal almost impossible.
- Don't cool off the bearing as you'll also shrink the cases.
References and further reading:
- How to clean ball bearings
- How are ball bearings mad
- Ball bearing sizes guide
- Ball bearing types and uses
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Step 1: Removing a Malfunctioning Bearing
Option 1: Pullers and presses
- Time efficient.
- Minimizes damage to the shaft and housing.
- Use two or three jaw mechanical pullers.
Option 2: Separator
- Easy removal if you use a heavy duty separator.
- Be careful when using a high-speed tool as you may damage the shaft or housing. Although necessary in some situations, this can directly affect the dimensional tolerance, which is crucial.
- If you can, avoid making flames and sparks during the process.
- Examine the removed bearing to see what caused the failure, so you can fix other problems and increase the longevity of your machine and its parts.
Step 2: Be Careful When Handling the Bearing While in Storage and During Installation
Make sure you got the following storage conditions:
- Vibration Free
- Unwrap the product just before installation.
- Keep the layer of factory lubricant on or you have tough time mounting the bearing. This amount follows all the necessary requirements.
Step 3: Make Sure You Got the Right Product Variation
To know you're using the right product you can:
- Take measurements
- Check the part number
- Cross reference the product number with the manufacturer catalog, so you can make sure you get the right dimensions and tolerance level.
- Using a slide caliper is usually enough.
- If not, you can use a Vernier micrometer that can measure up to 0.0001 inch.
Step 4: Keep the Shaft and Housing Clean Free of Gouges and Burrs
- Use Scotch-Brite pads to deal with fretting and corrosion.
- Use light machine oil to deal with moisture and acids.
- Avoid using emery paper as its particles may harm the bearing.
Step 5: Measure and Check Whether the Shaft and Housing Bore Fit the Bearing
You should check whether the dimensional tolerance fits with the bearing size.
You can again use your micrometer or slide caliper.
An eight-point measuring method is recommended for both the shaft and housing. This involves four measurements at various locations to determine that the shaft and housing are not elliptical and the sides are parallel.
An oversized shaft or undersized housing will reduce the required internal clearance in the bearing. This clearance is necessary to make for free rotation of the rolling elements, lubrication film and the metal expansion that will occur because of thermal changes.
Fits that are too loose will cause the bearing to walk or creep, pulling metal, which inevitably ends up in the bearing.
Remember, measure prior to mounting.
The three general types of fits are:
- interference or tight,
- line-to-line, and
- clearance or loose.
The fit is determined by:
- The nature of the application,
- type of bearing and
- which ring is rotating.
Step 6: Bearings Less Than 50 Millimeters (mm) in Diameter May Be Mounted by Using a Bearing Driver
This can be done only when the rings are installed with a light interference fit.
The tools used here have three main elements:
- metallic tube,
- polymer impact rings and
- dead blow hammer.
Just make sure you're using the right size.
Step 7: Arbor Press Is a Safe Method
Mount the arbor press to a working table and use the handle for leverage by applying pressure one step at the time. By doing this you'll lover the rack and unmount the bearing.
Don't add a pipe or any other holding element to the handle as you may damage the press and the bearing.
Step 8: Hydraulic Press Is a Fast Method If You Know What You're Doing
Hydraulic press will get the job done, but you must know how to operate one as the pressure of the tools can lead to serious injuries.
If an inexperienced mechanic is performing the operation, a proper installation and removal training should take place.