Seizure Recovery System For Fuel System Distributor

Final Report Presentation

Sponsored by Cummins Engine Company

Team #11

Michal Brown, Keron Miller,

Sean Edwards, Ben Nuttall

• Cummins has a fuel system distributor in production that seizes during overheating or debris ingestion.

• The warranty cost associated with the repair of the part is significant.

• Down time due to part failure is too long.

Background Information:

Customer Needs:

• Our objective is to design a mechanism that will enable the rotor to break away from the gear pump shaft when the rotor seizes and then re-engage at the same timing.

Specifications:• Target disengagement torque of 30 in-lbs• Drag torque while disengaged should be less than 5

in-lbs• Must have a torsional fatigue life of 10 million

cycles • Must be able to disengage/re-engage for at least 100

seizures without loss of torque• Must be able to re-engage in the same angular

position as disengagement• Shaft alignment must be maintained

Specifications:• Wear resistance must be as good or better than the

current design

• Must be backwards compatible with the existing system with the exception of the existing driveshaft. This implies that the new parts must occupy the same amount of volumetric space as the existing design

• Parts must add less than $21 to the cost of the engine

Photos

Photos

Customer Interim SolutionPart modifications:

Work Breakdown StructureMain Headings

1.0 Identify Customer Needs

2.0 Concept development

3.0 Analysis and Calculations

4.0 Manufacturing Drawings

5.0 Create Prototype(s)

6.0 Reports, Presentations, Meetings

Changes to Schedule

-Concept analysis is extended into next semester

-Final concept selection is delayed

-Start date of manufacturing drawings is delayed

Concept Analysis• Free body diagrams were created for each

concept.

• A summation of forces was conducted.

• The spring constants required to keep the design in equilibrium below the disengagement torque level were determined.

• A search for suitable springs was conducted.

Concept Analysis - Concept #1

Result: Spring constants of 16-250 N/mm were found

Concept Analysis - Concept #2

Suitable springs were found to accommodate the geometry and spring rates ranged from 26-300 N/mm .

Concept Analysis - Concept #3Spring constants of 20-226 N/mm were found. Springs that might fit within the geometry of the design are difficult to find.

Concept Analysis - Concept #4

Springs can be obtained to fit within the geometry. Our analysis yielded a spring constant of 134 N/mm for an angle of 20 deg.

Concept Analysis - Summary

Concept 1 -cannot go in reverse-springs needed are toolarge

Concept 2 -can go in reverse-springs needed can beobtained

Concept 3 -can go in reverse-springs needed are toolarge

Concept 4 -can go in reverse-springs needed areavailable

ProE Drawing - Concept #2

ProE Drawing - Concept #4

Comparison Criteria• Cost

• Ease of fabrication, assembly, installation and repair

• Fatigue life - wear (ball & groove, surfaces)

• Drag torque

• Repeatability (disengagement torque)

• Alignment, negative torque

Spring Semester Milestones:• Upon confirmation from our project

sponsor, we would like to accomplish the following tasks for next semester.

• Add friction to force anaylsis.

• Determine drag torque while disengaged.

• Find fatigue life and wear of components.

• Select suitable materials for prototype.

• Create engineering drawings.

• Build and test prototype.

Spring Semester Milestones:• Depending on the results of our future

analysis, it may be necessary to modify the concepts or develop new ones.

• We continue to update our webpage:

www.eng.fsu.edu/~nuttall/cummins

Questions?