Pre-Mature failure of bearing in Machine Spindles are due to various reasons:
- Unbalanced Tool Holder, collet, tools.
- Entry of Dust Particles/ contamination.
- Wrong usage.
- Insufficient cooling.
- Overheating because of no rest for the Spindle.
- Insufficient Lubrication.
1 .Unbalanced Tool Holder, collets and Cutting Tool:
MachineSpindles are designed for 6,000 rpm to 60,000 rpm depending upon the application. If the tool holder, collet and cutting toolis not balanced for Spindle rpm, it will generate excess force and causes pre-mature bearing failure. Solution for this problem is to use balanced Tool Holder, collets and cutting Tools.
- Entry of dust particles/ contamination:
If the machine is not having proper chips/dust removal mechanism, they may enter spindle and cause premature spindle bearing failure.Solution for this problem is to use vacuum dust collectors, avoid using pneumatic air for cleaning inside the machine. Also using of air purging, one can avoid dust particles entering inside the spindle.
3. Wrong Usage:
We observed so many customers using wood working spindles for marble carving, steel engraving. Then the spindle bearing fail because of excessive load.
Also most of the wood working spindles are not designed for handling wet cutting. If the water enters the spindle, it damages the collet, rotor shaft and spindle bearings. Before using the spindle discuss with the supplier whether the spindle is designed to handle the wet cutting, cutting loads.
4. Insufficient Cooling and No rest for the Spindle.
See the typical spindle bearing failure because of overheating.
Air cooled wood working spindle require 1-hour rest after 8 hours of continuous running.But most of the customers are not aware of this and they use the spindle more than 20 hours continuously. Then the Spindle becomes very hot and bearings fail pre-maturely. Solution: 1) Give rest to the air-cooledspindle after 8 hours continues running or keep the machine in Air-conditioned room. 2) Switch to water cooled spindle and use chiller for cooling the spindle.
5. Insufficient Lubrication:
Insufficient lubrication leads to excessive wear, over heating and subsequent bearing failure.
If the machine spindle is idle for two months. Bearing will not get proper lubrication. It is advised to rotate the spindle every 15 days, so that the proper lubrication happens.
Do not start the machining process directly when you are starting the machine in cold.Always run the spindle with tool for 2 minutes in idle condition at maximum rpm. This will increasethe bearings life and spindle’s life!
