1 Clutch Selection for American Marine Z-Drive Product ETM 5131 Project Phillip Magee July, 2004

2 Problem Statement American Marine has approved a project for a new z-drive to replace the current Charlie and Delta products. The new z-drive project is currently in the conceptual phase. The purpose of this project is to select a clutch type to be used in a new z-drive design for American Marine. Clutch type selection has a large impact on the product’s overall design.

3 Objectives Information on available clutch types Information on clutch safety Information on clutch performance attributes and cost Clutch type selection for the new z-drive project

4 Approach Benchmarking Exercise Energy Trace and Barriers Diagram (ETBD) Preliminary Hazard List (PHL) Preliminary Hazard Analysis (PHA) Decision Analysis (VA / VE)

5 Alternatives Considered Twelve clutch types were brainstormed and considered in selection. The following clutch types were analyzed for safety DogConeWet Disk Dry Disk Band The following top 4 clutch type and driveline configurations were analyzed in a decision analysis. 1. Cone Clutch (Bravo Style) in the upper portion of the z-drive 2. Dog Clutch (Alpha Style) in the lower portion of the z-drive 3. Synchronized Toothed / Dog (w/ 2 Stage Engine Coupler) 4. Wet Disk Master Clutch (One Engine) / Dog Selector (In Drive)

6 Analysis & Results Benchmarking Provided a list of current clutches, their applications, and actuation systems This gave the team participants information to begin later processes ETBD Used a Diagram to organize the energy flow in the z-drive system and listed barriers to that flow. Focused the team on the importance of the clutch function for safety PHL Listed the hazards associated with a z-drive clutch Showed the team that a z-drive clutch fails in only 3 ways. To ForwardTo NeutralTo Reverse

7 Analysis & Results PHA Used FMEA to provide a Risk priority number to each failure mode of each clutch. Showed the team that the dog clutch only fails to neutral (Does not transmit power when it should be coupled). This gives the dog clutch a safety advantage.

8 Analysis & Results Decision Analysis Used team exercises and other data to: provide brainstorm clutch and driveline types set criteria weight criteria rank clutch and driveline types based on weighted criteria estimate the value of each clutch and driveline type. This presented the positive attributes of the dog clutch to the team and ultimately led to the modular z-drive configuration utilizing a dog and wet disk clutch.

9 Conclusion The clutch type and modular driveline selected for development Offers flexibility to satisfy low cost needs with a safe, reliable, and durable dog clutch While, giving the option to add a more expensive wet disk master clutch that provides greatly improved shift characteristics along with the safety, reliability, and durability of the dog clutch for premium products

10 Recommendations System models should be created for the modular driveline and shift characteristics should be analyzed based on these models. A prototype should be build and tested in the base product dog configuration and in the premium product dog selector and wet disk master clutch configuration. A detailed cost study should be completed along with more detailed designs. This activity can be completed by 12/17/04 within the current new z-drive engineering budget.

11 Use of MSETM Materials Benchmarking The benchmarking portion of this report used the concepts learned for process benchmarking in a light product benchmarking exercise System Safety The PHL and PHA processes learned in the system safety class were utilized in order to help direct a significant design selection in early design stages Failure Modes and Effects Analysis FMEA processes presented in the FMEA course were used to complete the PHA Problem Solving and Decision Making Decision analysis process attributes presented in the problem solving and decision analysis course were utilized to evaluate the clutch alternatives