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Due to the higher speed requirements and changes in environmental concerns, demands for lowered ball screw noise are on an increase. Quieter ball screws are needed especially in the areas of Factory Automation and Office Automation.
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| There are three possible sources of ball screw noises: from the ball screw itself, errors in mounting accuracy, and from the entire machinery as a whole. |
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Ball screw itself
Since the ball screws contain rolling elements that make contacts with other components, recirculating noises and rolling noises are unavoidable. Based on the researches on this subject, it is now known that small waviness on the screw shaft's groove surfaces have large effects on the ball screw noise. |
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Errors in mounting accuracy
Mounting inaccuracies in parallelism and perpendicularity during the installation can create uneven loads on the ball screw system, causing abnormal noises. This can be examined by temporarily loosening the mounting bolts and test-run the system to look for any reductions in the noise. |
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Machine as a whole
Some resonance may occur within the machine as a whole, including the ball screw. The possible causes may be the drive motors, feedback systems, and inadequate machine rigidity. |
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| Kuroda has long been focused on the ball screw generated noise issues, and continues to challenge in ball screw noise reduction efforts in the following areas. |
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Improvements in geometrical accuracies of ball rolling grooves |
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Reductions in surface waviness of ball rolling grooves |
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Improvements in surface finish smoothness |
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Optimizations in ball recirculating circuit designs. |
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| Our efforts in these improvements have contributed in large reductions in ball screw noises not only for the equipment for office uses such as plotters but for the industrial machinery such as machine tool and industrial robots as well. |
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| Application examples (Noise levels at 3000 rpm) |
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Ball Screw O.D.
mm
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Lead
mm
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Ball Screw Overall length
mm
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Sound Pressure
dB
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15
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10
15
20
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≤ (500 or less)
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58
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≤ (800 or less)
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62
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20
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20
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≤ (600 or less)
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62
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≤ (1200 or less)
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65
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| * Distance measured at |
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