SPOKE TUNER STATUS M. Merio, D. Passarelli, L. Ristori

Spoke Tuning System Requirementsvalueunit Cavity and Mechanical system specs Cavity end-wall spring constant N/mm Cavity elastic sensitivity at end-wall540.00kHz/mm Frequency range necessary for operation135.00kHz Stroke at BP0.25mm Max force at BP N Mech advantage between BP-NUT (RBPN)0.17 Mech advantage between BP-PIEZO (RBPP)0.50 Elastic efficiency between BP-NUT (EBPN)0.25 Elastic efficiency between BP-PIEZO (EBPP)0.25 Transmission coefficient from NUT (RBPNxEBPN)0.04 Transmission coefficient from PIEZO (RBPPxEBPP)0.13 Piezoelectric actuators specs (Fine tuning) Max force N Frequency range1.00kHz Stroke at BP1.85um Stroke cold14.81um Actuator assembly specs (Coarse tuning) Max Force at Nut pushing (safety operation)non-issueN Max Force at Nut pulling (normal operation) N Stroke6.00mm Frequency resolution0.02kHz Axial resolution at Nut888.89nm Lifetime linear travel of Nut mm

MODEL AND ASSUMPTIONS L/2 L S S/3 FULCRUM MAIN ARM PROBES Motor arm Drive nut STEPPER MOTOR PIEZOS Stretch adjustment Squeeze adjustment Assumptions: The Tuner is symmetric, only half model will be considered Material: SS316 L RT analysis Tuner with symmetry boundary conditions imposed

TUNER MAIN ARM Loads and Boundary Conditions:

MOTOR ARM – PIEZO Loads and Boundary Conditions:

MOTOR ARM – MOTOR Loads and Boundary Conditions:

MOTOR SUPPORT Loads and Boundary Conditions:

PLATE Loads and Boundary Conditions: Total Force acting on the bolts: Bolt 1Bolt 2Bolt 3Bolt 4 Force [N]

CONCLUSIONS A first coarse analysis has been done to evaluate the behavior of the main components of the tuner Stiffness and Stresses have been investigated Future work: Verify if the requirements listed before have been satisfied Thermal analysis Analysis of the entire assembly Failure analysis THANKS FOR THE ATTENTION