Angular Contact Bearings

Ball cages are used in machine tool spindles to allow the shaft to grow toward the rear of the spindle during thermal expansion. The rear bearing compliment rides inside the ball cage which enables them to move in an axial direction while capturing them in a radial direction.

Common causes of failure are:

• Worn surfaces of the ball paths causing looseness
• Divots in the ball paths restricting movement
• Worn rolling elements
• Improper installation causing ball cage damage

Results from ball cage failure:

• Bearing preload increases as thermal expansion occurs leading to overload and failure
• Vibration from looseness
• Poor part finish
• Premature spindle failure

Solutions:

• Grind plate grind ball cage housings to meet specifications
• Replace ball cage rolling elements
• Replace entire ball cage