Grease for Ballscrew Bearings and Nuts

Ball screws convert rotary motion to linear motion with high efficiency and precision. Proper lubrication of both the ball nut assembly and support bearings is essential for accuracy and longevity.

Ball Nut Lubrication

The ball nut contains recirculating balls that travel between the screw shaft and nut body. Lubrication requirements:

• Continuous lubricant supply to ball contact points
• No particle buildup that could affect accuracy
• Resistance to migration from reciprocating motion

Support Bearing Lubrication

Ball screw support bearings are typically angular contact ball bearings requiring:

• Compatible grease with ball nut lubricant
• Appropriate viscosity for bearing speed
• Long-term stability for sealed applications

Lubrication Methods

Method	Application	Interval
Manual greasing	Grease fittings on ball nut	Per manufacturer schedule
Reservoir system	Lubricant-impregnated felt	Check/replace periodically
Automatic system	Centralized dispensing	Continuous low-volume

Contamination Effects

Ball screw contamination causes:

• Increased friction and heat generation
• Accelerated wear of balls and raceways
• Positioning accuracy degradation
• Premature failure

Bellows or covers help protect ball screws from chips and coolant contamination.

Manufacturer Recommendations

Ball screw manufacturers typically test and approve specific lubricants for their products. Using approved lubricants ensures warranty coverage and documented performance.