SPOKE TUNER STATUS

M. Merio, D. Passarelli , L. Ristori

Spoke Tuning System Requirements value unit

Cavity and Mechanical system specsCavity end-wall spring constant 30000.00 N/mmCavity elastic sensitivity at end-wall 540.00 kHz/mmFrequency range necessary for operation 135.00 kHzStroke at BP 0.25 mmMax force at BP 7500.00 NMech advantage between BP-NUT (RBPN) 0.17Mech advantage between BP-PIEZO (RBPP) 0.50Elastic efficiency between BP-NUT (EBPN) 0.25Elastic efficiency between BP-PIEZO (EBPP) 0.25Transmission coefficient from NUT (RBPNxEBPN) 0.04Transmission coefficient from PIEZO (RBPPxEBPP) 0.13

Piezoelectric actuators specs (Fine tuning)Max force 3750.00 NFrequency range 1.00 kHzStroke at BP 1.85 umStroke cold 14.81 um

Actuator assembly specs (Coarse tuning)Max Force at Nut pushing (safety operation) non-issue NMax Force at Nut pulling (normal operation) 1250.00 NStroke 6.00 mmFrequency resolution 0.02 kHzAxial resolution at Nut 888.89 nmLifetime linear travel of Nut 1500.00 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:

Stiffness

𝝈𝒆𝒒𝑴𝑨𝑿=𝟒𝟖𝑴𝑷𝒂

MOTOR ARM – Load @ PIEZOLoads and Boundary Conditions:

Stiffness

MOTOR ARM – Load @ MOTORLoads and Boundary Conditions:

Stiffness

𝝈𝒆𝒒𝑴𝑨𝑿=𝟖𝟑𝑴𝑷𝒂

MOTOR SUPPORTLoads and Boundary Conditions:

Stiffness

𝝈𝒆𝒒𝑴𝑨𝑿=𝟑𝟑𝑴𝑷𝒂

PLATELoads and Boundary Conditions:

Total Force acting on the bolts:

Bolt 1 Bolt 2 Bolt 3 Bolt 4

Force [N] 925.94 645.41 422.08 262.85

𝝈𝒆𝒒𝑴𝑨𝑿=𝟏𝟓𝑴𝑷𝒂

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