Leadscrew taskforce report

L. GentiniFrancois-Xavier Nuiry, Inigo Lamas, Jerome Lendaro, Manuele Narduzzi, Maxime

Bergeret, Mickael Crouvizier, Patrice Francon, Pierre Gander.

HiColDem8th November, 2018

EDMS: 1760258

08-11-2018

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DRY SCREW TESTED

UMBRA: Recirculating ball screws

Screw and nut in St. Steel + ceramic balls

Screw and nut in St. Steel + ceramic / St. Steel balls

KSK: Recirculating ball screws

Screw and nut in St. Steel + St. Steel balls

SKF: Recirculating roller screws

Screw and roller in St. steel with Dicronite coating nut in St. steel

KUGEL MOTION: Recirculating roller screws

Screw and nut in St. steel with Dicronite coating

ROLLVIS: Satellite roller screws

Screw and nut in St. steel with WC/C and Rollers in St. Steel with WC/C + Dicronit coating

Luca Gentini– EN-MME08-11-2018

Supplier Max number of cycles

UMBRA 1050

KSK 150

SKF 3300

Kugel motion 907

ROLLVIS 35000

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SCREW MOVEMENTS

Recirculating ball screws

Recirculating roller screws

Satellite roller screws

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ROLLVIS SCREW TEST PARAMETERS

• Cycle profile: same of the LHC but faster

• Screw assembled on the upper position (1.4 kN max)

• Each 10.000 cycles the screws is dismounted for a visual test

• Check manually the play

• Microscope pictures

• A new servo-type motor drive developed by EN-SMM used:

• Monitoring the current, we calculate the proportional torque.

• Smoother motion due to dumping of the oscillatory open loop dynamics.

• Less vibrations, less noise and less wear.

• Data acquisition every 100 cycles (55 sec)

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ROLLVIS SCREW TEST RESULTS

Typical acquisition

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ROLLVIS SCREW TEST RESULTS

Average current of each acquisition (350) on 35000 cycles

Part 1

Part 2

Part 3

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ROLLVIS SCREW TEST RESULTS

Maximum current of each acquisition (350) on 35000 cycles

The current has reached around 1500 mA, whereas the maximum current that the motor can handle is about 2800 mA. Thus, we are at 50% of the maximum current/torque that the motor can provide.

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ROLLVIS SCREW TEST RESULTS

Digital microscope analysis shows a wearing of the screw threat. But no motor steps lost and the functionality of the screw is still respected.

Rusty sideSafe side

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ROLLVIS SCREW TEST RESULTS

The cycled screws seams totally oxidized

Rusty sideSafe side

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On-going Actions

• ROLLVIS cycled screw has been sent to rollvis to be dismounted and analyzed

• ROLLVIS experts will come at CERN to make conclusion after analysis.

• A second Rollvis is now cycling on the bottom side of the mechanical table (2 kN -~400mA more)

• For the TDIS, because of UMBRA delivery late, a lubricated rollvis screw has been ordered. On this screw a quick lubrication system will be embarked. No coating required whit lubricant. Possibility to modify mechanical table components to use the same system everywhere.

Luca Gentini– EN-MME08-11-2018

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Conclusion / Open points

• The only screw which reached the target is ROLLVIS. The others are far away.

• Can be the difference attribute to the screw system?

• Do we want to test others screws whit the same system?

• Other cycling test are on-going on ROLLVIS for statistic, but even if others screws have same results, are the ROLLVIS screw approved as a dry solution?

• If we want to have a combined solution (lubricated screw with quick lubrication which can works whit-out lubricant for a lap of time) can we test a ROLLVIS dry screw without-out coating?

Luca Gentini– EN-MME08-11-2018

Thanks for your attention

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