C50 Cryomodule Cavity Tuner Study Evaluation of Planetary Gear Box Installed on Tuner Mechanism

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JLAB-TN-08-056 C50 Cryomodule Cavity Tuner Study Evaluation of Planetary Gear Box Installed on Tuner Mechanism Hrishikesh Phadke, Ed Daly 1.

1 JLAB-TN C50 Cryomodule Cavity Tuner Study Evaluation of Planetary Gear Box Installed on Tuner Mechanism Hrishikesh Phadke, Ed Daly 1. INTRODUCTION As part of NL-12 decommissioning, tuner testing was conducted on cavities 1 and 2 to determine the tuning sensitivity and backlash with planetary gear box added to the original CEBAF tuner system. The necessity of high torque output made the installation of the gear box necessary into the system. With 3:1 gear ratio the gear box facilitated three times higher torque output. The disadvantage of using the gear box is the increased number of rotations to achieve the same frequency change. An alternative solution to increasing torque would be installation of higher torque motor. A higher torque motor would require changing the input connections to the motor and thus would be a costly alternative. Hence it was decided to use a gear box with higher torque output. Figure 1: Lab view GUI showing Frequency Settings and Sensitivity Curve 1

2. INITIAL DATA FOR THE TESTS Number of steps of motor= 6000 Full Range Span on Network Analyzer= 4 KHz Velocity = 25 rpm Acceleration = 10 rps/s High Frequency Limit= MHz Low Frequency Limit= MHz 3.

2 2. INITIAL DATA FOR THE TESTS Number of steps of motor= 6000 Full Range Span on Network Analyzer= 4 KHz Velocity = 25 rpm Acceleration = 10 rps/s High Frequency Limit= MHz Low Frequency Limit= MHz 3. TEST SETUP Description of Gear Box Company: Neugart USA, LP 3047 Industrial Blvd. Bethel Park, PA Specifications of Motor: PLE60 i=3/opx/nema 23 Stepper Ratio: 3 (1 Stage) OPX= NEMA 23 Output Flange Adapter Flange 60X60- PLE60 NEMA23 23/38.1/66.7/B5/M Bushing /Sleeve-d= 14/ Output Adapter Flange 60X60- PLE60-NEMA 23 With motor mounting screws (M4X12) S/N: Figure 2: Gear Box Installed on Cavity 2

3 4. TEST RESULTS AND DISCUSSION The difference between the frequency values from the experiment and the pressure compensated frequency is negligible. Hence the frequency values from the experiment have been taken to plot the graphs. a. First Test on Cavity 1 Table 1: First Set of Frequency Readings for Experiment on Cavity 1 with Gear Box Figure 3: Frequency Sensitivity for Test 1 on Cavity 1 The backlash at the beginning of the experiment is approximately steps. The frequency decreases until MHz, then the direction is reversed and again a backlash of steps is observed. This is a very high backlash for 3:1 ratio stepper motor. The coupling between the motor and gear box was suspected to be loose, causing slippage. The coupling was 3

4 tightened and the test was conducted again. To avoid this problem in production, a keyed coupling or stepper motor with a flat on the shaft is recommended. b. Second Test on Cavity 1 Table 2: Second Set of Frequency Readings for Experiment on Cavity 1 with Gear Box Figure 4: Frequency Sensitivity for Test 2 on Cavity 1 The backlash at the beginning of the experiment is steps. The frequency decreases until MHz. After the direction is reversed, a backlash of steps is observed. Tightening the coupling eliminated the slippage. The backlash did not change, remaining steps. Tuner hysteresis data for cavity 1 without the gear box is unavailable because testing was not conducted on this production cavity. Data for all other cavities is available. 4

5 c. First Test on Cavity 2 Without Gear Box Table 3: First Set of Frequency Readings for Experiment on Cavity 2 with Gear Box and Without Gear Box Without GearBox Figure 5: Frequency Sensitivity for Test1 on Cavity 2 Backlash at the beginning of the experiment is steps. Backlash at direction reversal is steps. The cavity frequency sensitivity with the gear box is Hz/µstep, while the cavity frequency without the gear box is Hz/µstep. The gear box reduction (3:1) changes the cavity frequency as expected. 5

6 d. Second Test on Cavity 2 Without Gear Box Table 4: Second Set of Frequency Readings for Experiment on Cavity 2 with Gear Box and Without Gear Box At the start and at direction reversal, an equal backlash of steps is observed. The program is again terminated as the frequency reaches upper limiting frequency of.003 MHz. The cavity frequency sensitivity with the gear box is Hz/µstep, while the cavity frequency without the gear box is Hz/µstep. The gear box reduction (3:1) changes the cavity frequency as expected Without GearBox Figure 6: Frequency Sensitivity for Test 2 on Cavity 2 6

7 5. CONCLUSION The 3:1 ratio stepper motor reduces the cavity frequency sensitivity by a factor of three. Throughout the experiments a consistent backlash of approximately steps has been observed and is consistent with CEBAF tuner performance. Slippage between couplings can be reduced by adding keys or flats on motor shaft. The controls and data acquisition program should be improved to run more stably. 6. FURTHER WORK This test was conducted on a cryomodule that is scheduled for disassembly. The tuner mechanisms possesses large backlash because of original hardware limitations. The refurbishment effort includes adding an improved tuner transmission which reduces the backlash. More tests should be done on refurbished cryomodule, such as C50-CM7, to evaluate the gearbox performance on an improved tuner mechanism. 7

C100- Cryomodule Waveguide Temperature Profile and Heat Loads for Applied Heat Stations and RF Power

C100- Cryomodule Waveguide Temperature Profile and Heat Loads for Applied Heat Stations and RF Power JLAB-TN-9-1 March 5,29 C1- Cryomodule Waveguide Temperature Profile and Heat Loads for Applied Heat Stations and RF Power 1. INTRODUCTION Hrishikesh Phadke, Edward Daly A thermal analysis was performed