Clutch Selection
for American Marine Z-drive Product
Submitted to:
The Faculty of the MSETM Program
Oklahoma State University
Stillwater, OK
Submitted by:
Phillip Magee
Stillwater, OK
Date Submitted:
July, 2004
Page 1 of 32
EXECUTIVE SUMMARY
The dog clutch has been chosen for use in the new z-drive concept as a primary forward,
neutral, reverse clutch, and gear selector. The value based product will only contain the
dog clutch while the premium product will also have an optional wet disk master clutch
on the engine for decoupling torque during shifting and greatly improving shift
aesthetics.
Clutch type selection and drive-line configuration is necessary early in the new z-drive
project in order to set basic design direction. Using the dog clutch in the base product will
enable American Marine to maintain current costs on value based products while
providing a safe, robust, and reliable clutching mechanism. The ability to add an optional
wet disk master clutch to the dog clutch, for decoupling torque during shifting, will
provide the best shift aesthetics in the industry and give American Marine the ability to
satisfy the desires of the growing market of discriminating boating customers without
sacrificing safety, robustness, or reliability.
Dog, cone, wet disk, dry disk, and band clutches were investigated. Magnetic clutches,
belt clutches, sprag clutches, spring clutches, and torque converters were also
brainstormed as clutch alternatives. These clutches were analyzed in several drive-line
configurations. Single cone and dog clutch systems were discussed along with
synchronized dog clutches. Wet and dry master clutches with dog clutch gear selectors
were also analyzed along with a torque converter and cone clutch combination.
Clutch types and drive-line configurations were analyzed using benchmarking, energy
trance and barrier diagramming, preliminary hazard listing, preliminary hazard analysis,
and decision analysis. The benchmarking simply listed the major clutch alternatives and
their current or past applications. The energy trace and barrier diagramming supported
the need for a focus on design safety in the clutch. The preliminary hazard list presented
the available hazards of a clutch. The preliminary hazard analysis ranked each failure
mode of each clutch type to determine the least hazardous clutch type. The decision
analysis set and weighted criteria for judging overall clutch function and ranked each
clutch according to the criteria. This process also used estimated costing of each clutch
and drive-line configuration to evaluate the value of each alternative. This overall
process highlighted the safe and cost effective design characteristics of the dog clutch.
The process also revealed that the wet disk clutch is needed to achieve the improved shift
aesthetics in the new z-drive project. A modular approach that utilizes the dog clutch for
a base product and an optional master wet disk clutch for refined premium drive systems
was the final outcome of the knowledge gained from the processes in this project.
A prototype of the premium system has been built and is proving to provide undetectable
shift events. The team is working to define proper sizing and control components. A
design concept with working prototype and detailed costing information will be available
by December 17, 2004 with current project funding ($250,000). This will satisfy the
current approved project schedule by preparing for the new z-drive product
implementation process prior to January 1, 2005.
Page 2 of 32
INTRODUCTION
This project was conducted as a set of engineering processes used to provide information
in order to drive a decision on the type of clutch to be used in American Marine’s new zdrive product line.
The project purpose is discussed first in order to establish the need for the project and
how it fits into American Marine’s strategy. Then the project’s approach is described and
the engineering procedures are explained. A listing of the alternative clutch types
considered and their source is also included. The analysis and results make up the
majority of this project report.
Each of the following engineering processes used will be discussed in detail.
First, a benchmarking exercise is used to document clutch types that are readily available.
Next, and energy trace and barriers diagram (ETBD) is explained. Then, a preliminary
hazard list (PHL) clearly lists opportunities for clutch failures. Once the PHL is
complete, a preliminary hazard analysis uses failure modes and effects analysis on a
generic clutch and on selected clutch types. A decision analysis that follows the value
analysis / value (VA / VE) engineering procedure is utilized last.
Finally, conclusions and recommendations generated from the above processes are
clearly stated. Clutch type selections are made and the recommendations for further
development are defined.
Appendixes A through E contain actual data from each engineering process used in
clutch selection.
Appendix
A
Benchmarking Exercise
B
Energy Trace and Barriers Diagram
C
Preliminary Hazard List
D
Preliminary Hazard Analysis (FMEA)
E
Decision Analysis
PROJECT PURPOSE
This project’s purpose was to select a clutch type to be used in a new z-drive design for
American Marine. The new z-drive project is currently in the conceptual phase. The
American Marine research and development team is scheduled to complete concept
development by December 17, 2004. Clutch type selection has been completed and is a
major decision that must be made in z-drive design. The type of clutch selected highly
influences overall safety, manufacturability, reliability, and durability of the z-drive while
dictating noise, vibration, and harshness characteristics.
Page 3 of 32
American Marine designs and produces z-drive engine packages for the recreational and
light commercial marine markets. These engine packages utilize an automotive based
engine with marinized cooling, exhaust, and electrical systems. The powertrain of the zdrive package transmits the rotational power from the engine to the propeller. The z-drive
also steers the propeller for directional control and trims the propeller by changing its
angle to vector the propeller thrust force. Trimming improves vessel acceleration and top
speed. The z-drive power system also provides shifting in forward, neutral, and reverse.
One last major function of the z-drive powertrain is to tilt the propeller up for trailering of
the vessel.
The z-drive product at American Marine currently consists of two lines of z-drive
propulsion systems. The Charlie product is used on four cylinder, V6, and small block V8
engines from 130 horsepower to 300 horsepower. This z-drive is currently offered with a
single propeller in several gear ratios for different engine sizes and boat weights. The
basic Charlie z-drive design has been in production since 1965 with evolutionary
development and feature additions. The second z-drive product line is the Delta z-drive.
This product is used on V6, small block V8, and big block V8 engines from 230
horsepower to 575 horsepower. There is a matrix of product line extensions for the Delta
z-drive. This drive is offered in single propeller sport (Delta I), single propeller low speed
(Delta II), and dual propeller sport (Delta III) versions. These versions are offered in
standard, Diesel X, Performance X, and Racing XR versions. Several gear ratios are
provided for each z-drive to optimize performance in different boats with each engine
option.
The z-drive driveline is very simplistic and robust. In the past, great attention has been
made to ensure that the American Marine z-drives are the most durable and reliable zdrives on the market. Customers have demanded durability and reliability in the
recreational and light commercial marine engine markets. Historically, product esthetics
that deal with NVH (noise, vibration, and harshness) have been on the customer delight
level. The shift systems in the current Charlie and Delta z-drive products do not address
NVH issues well. Recently, customers have become more sensitive to NVH issues. 2002
and 2003 J.D. Power surveys have scored the American Marine z-drive products below
Volvo z-drives in NVH characteristics. Volvo z-drives are currently the only major
competitive z-drive product.
American Marine has approved a program to design and develop new z-drive products to
replace the current Charlie and Delta z-drives. The development of new z-drives allows
consideration of new clutch mechanisms to address customer NVH desires to a level that
the current clutch and gear selection mechanisms can not achieve.
This project is a small, but critical component of the new z-drive program and has
provided the basic building blocks to design the new z-drive. The proper selection of the
clutch component is crucial in the success of the entire new z-drive program and the long
term competitiveness of American Marine in the future z-drive marketplace. This project
has successfully selected a clutch type and configuration to be used in the new z-drive
Page 4 of 32
concept. Modeling, analysis, and prototype construction has started in order to investigate
the z-drive concepts based on the clutch configuration chosen in this project.
APPROACH
Process Flow Chart –
The following five processes were used in the clutch types
and driveline configuration selection.
Benchmarking Exercise
Energy Trace and Barriers
Diagram (ETBD)
Preliminary Hazard List (PHL)
Preliminary Hazard Analysis
(PHA)
Decision Analysis (VA / VE)
Each process builds upon the overall knowledge of the clutch in order to provide data for
the final decision analysis. While the process participants were completing each stage of
the process, they also gained experience with the component and were allowed time to
develop a good understanding of the component and its intricacies.
The benchmarking exercise started the project. Four veteran American Marine employees
with over 85 years of combined marine experience developed a list of clutches
in order to clarify the roles of the z-drive components from a safety view point. This
exercise was used to pool information on the available clutch types and their applications.
Participants in the following processes were introduced to the benchmarking material
prior to each exercise.
Page 5 of 32
An energy trace and barriers diagram was completed in order to graphically represent the
drive line and draw focus to the components and systems that have the ability to impart
energy into a human.
A PHL was developed for the clutch by a cross functional team. This list contains each
basic failure of a generic clutch. This list was made prior to clutch hazard analysis in
order to simply list basic failures and gain clarity of the ways any clutch can fail.
A PHA was then completed, by a cross functional team, in order to gain a better
understanding of clutch failure modes and their effects. The process used for this analysis
was failure modes and effects analysis.
After the benchmarking and safety based processes were completed for input data, a
decision analysis was carried out using a VA / VE process. This process used a cross
functional team from marketing, service engineering, manufacturing, and quality in a
weighted criteria ranking process. During this process, the team realized the clutch type
decision is closely related to the driveline configuration. In order properly rank the clutch
type, the driveline configuration was also brainstormed and analyzed along with the
clutch type. The cross functional team then decided on a clutch type and driveline
configuration for the new z-drive. This decision used the information gathered and
analyzed in the five preceding processes. The VA / VE process was used to organize the
data collected in the above procedures along with data from marketing research,
manufacturing, and quality in order to guide a decision on the clutch type to be used in
the new z-drive.
ALTERNATIVES CONSIDERED
The benchmarking exercise delivered 5 basic clutch types used internally, by the marine
industry, or in the automotive and off-highway industries. Hazard analysis was conducted
on these five clutch types in order to provide input in the decision analysis. The decision
analysis utilized brainstorming to list 12 clutch types. These twelve types were condensed
to seven overall clutch and drive line system configurations in a group exercise. Then, the
top five clutch types and drive line configurations were ranked according to weighted
criteria. The top four clutch type and driveline configurations were:
1.
2.
3.
4.
Cone Clutch (Bravo Style) in the upper portion of the z-drive
Dog Clutch (Alpha Style) in the lower portion of the z-drive
Synchronized Toothed / Dog (w/ 2 Stage Engine Coupler)
Wet Disk Master Clutch (One Engine) / Dog Selector (In Drive)
Page 6 of 32
ANALYSIS AND RESULTS
Benchmarking
The clutch type benchmarking document can be viewed in appendix A. Brainstorming
was used in a small group of experts for this activity. Six clutch types were listed. Their
usage was broken into the following three categories.
Internal (Mercury Marine)
Industry (Recreational / Light Commercial Marine)
Functional (Automotive / Off Highway)
Their product name, application in the system, and means of actuation were listed. This
list was generated to provide information to the cross-functional team members in the
PHA and VA / VE processes. This list was composed of six major clutch types used in
similar applications. It provided a great starting point for team conversation and helped
the team members to get familiar with the clutch component prior to starting their own
group activities. Ultimately, this list contained the clutch type selected by the team.
Energy Trace and Barriers Diagram (ETBD)
The deliverable of this process can be found in appendix B. This process was conducted
by Phillip Magee and was also designed to be used as information in the following PHA
and VA / VE group processes. This process basically uses a diagram to represent the
current Charlie and Delta z-drive configurations. A table below the diagram lists the type
of energy present in each component or subsystem and any barriers to this energy. This
process is based on the theory that any injury to humans must be caused by energy being
imparted into them. For this reason, it is critical to trace the energy in the system and be
aware of any place that this energy is not barred from human contact. This process has
shown that the propeller is the only part of the driveline that has energy available to
human contact. The propeller is used to impart energy into the water to propel the boat.
This is similar to a tire on an automobile imparting energy to the ground to propel the
automobile. This diagram also shows that the propeller energy is controlled by the clutch.
The decoupling of the clutch is the action that does not allow the propeller to contain
rotational energy and is of high importance when designing a driveline. The ETBD was
used to document the energy and barriers in the z-drive and focus attention on the areas
critical for imparting energy. The propeller was targeted as the component that imparts
energy. Within the project guidelines, the z-drive and propeller configuration are given
and must be maintained. This drives the focus of the energy to the clutch which acts as a
switch to either transmit power or decouple it from the propeller. This document was
presented to participants in the PHA and VA / VE as support information. The ETBD
was successful in targeting the clutch as an important component and relaying its
function as an energy barrier to the cross-functional team.
Page 7 of 32
Preliminary Hazard List (PHL)
The preliminary hazard list is can be found in appendix C. This list was done prior to the
PHA and decision analysis in order to simply list the hazards associated with clutches of
any type. This list was instrumental in presenting each type of hazard of the clutch. It was
quite evident to the team that the clutch failure to forward or to reverse would mean that
the driveline would be supplying rotating energy to the propeller when the operator
thought the propeller was static. These two hazards were clearly seen as the least
desirable for the design. It was also clearly seen that the clutch failure to neutral was less
critical from a safety viewpoint. This list also allowed the team to discuss the mobility
failures of the clutch when it fails to neutral. At this point the team understood the
hazards of the clutch in a z-drive. Now, a FMEA was needed to better analyze the details
of the clutch hazards.
Preliminary Hazard Analysis (PHA – FMEA)
The generic clutch portion of the PHA can be found in appendix D. PHAs of each clutch
type were also completed, but have not been listed in the appendix. They are very similar
to the PHA for the generic clutch. Differences of each clutch type as compared to the
generic clutch PHA are listed in appendix D. The FMEA process was used to perform a
PHA on a generic clutch and five clutch types (Dog, Cone, Wet Disk, Dry Disk, and
Band). This was a team process. The team was shown the benchmarking study and the
ETBD prior to the FMEA process. In this process, each failure was analyzed by listing
each failure mode along with its cause, effect, and design validation process. Severity,
occurrence, and detection rates were scored and an overall risk priority number was
developed for each failure mode. During this process, it was evident that the dog clutch is
superior to the other clutches because it does not have the ability to fail in a way that
would cause it to transmit torque when it should not transmit torque. This process also
ranked that failure with the highest possible severity number of 10 and a high overall risk
priority number of 120. This data was used in the following decision analysis.
Decision Analysis (VA / VE)
The VA / VE can be viewed in appendix E. The Benchmarking data, ETBD, PHL, and
PHA were used as supporting documentation in the VA / VE. In the VA / VE, the clutch
functions were listed and analyzed. Then a list of twelve clutch types was brainstormed to
insure that all types were considered. At this point, it was evident to the group that the
way a clutch is used in the system is important to its function and the way it would be
ranked. The group then brainstormed a total of seven clutch type and drive-line
configurations.
Page 8 of 32
Idea # Description
1
2
3
4
5
6
7
Cone Clutch (Bravo Style)
Dog Clutch (Alpha Style)
Synchronized Toothed / Dog (w 2 Stage Engine Coupler)
Wet Disk Master Clutch (On Eng.) / Dog Gear Selector ( In Drive)
Wet Disk Synchronized Dog Master Clutch (On Eng.) / Dog Gear Selector (In Drive)
Dry Disk Master Clutch (On Eng.) / Cone Clutch Gear Selector (In Drive)
Torque Converter (On Eng.) / Cone Clutch Gear Selector (In Drive)
The top four clutch and drive-line configurations were T charted by the team in order to
list pros and cons for each. Each con was discussed to attempt a solution. At this point the
team was familiar with each configuration and was ready for developing weighted criteria
and ranking. Eight criteria were developed for the configuration and given a weight using
a paired comparison matrix. Then the “must” and “want” criteria were separated to draw
a line between criteria that are necessary and criteria that are desirable.
Eval. Criteria
Safety (Must)
Reliability (Must)
Durability Envir./Time/Cycles (Must)
NVH (Want)
Packaging (Want)
Serviceability / Maintenance (Want)
MFG. Mach. / Assy. (Want)
Styling (Want)
Rating %
25.0
21.4
17.9
14.3
10.7
7.1
3.6
0.0
100
Each configuration was ranked in its ability to meet the criteria on a scale of 1 to 10.
These rankings were weighted and added for each criteria to develop an overall score.
That score was then divided by the cost of the clutch and necessary mating components
in the driveline to develop a valued based score. Safety, reliability, and durability were
determined to be “musts” and are highly weighted. This affected the overall score of the
clutch types. The dog clutch ranked the highest based on the weighted criteria and the
value. The wet disk master clutch on the engine and dog gear selector in the drive idea
ranked second based on the criteria but last from a value perspective due to its higher
cost. The cone clutch ranked third from criteria and a distant second in value. The
synchronized toothed / dog clutch ranked last based on the criteria and third in value.
Clearly, the dog clutch was found to be the best overall clutch for satisfying customer
needs and it greatly exceeded the other clutch types from a value perspective.
Page 9 of 32
VA / VE Results
Total Weighted Criteria Rank
Estimated Cost
Value Ratio
Criteria/Cost
Idea 1
Idea 2
Idea 3
Idea 4
671.4
789.3
589.3
725.0
$100.00
$50.00
$120.00
$170.00
6.7
15.8
4.9
4.3
The cross functional team discussed the results of all five of the above processes and their
feelings about the validity of the results. The team agreed that the results were valid. The
dog clutch has always been found to be safe, reliable, durable, and very cost effective.
Several attempts have been made in the past to replace it, but they have all failed at
providing a better yet cost effective clutch alternative.
CONCLUSIONS AND RECOMMENDATIONS
The team used the information developed in this project along with marketing input to
develop a z-drive strategy that would utilize the positive attributes and low cost of a dog
clutch for cost sensitive customers while allowing for design flexibility and satisfying the
needs and wants of more discriminating customers willing to pay more for a more refined
product.
The team proposes a base product utilizing a dog clutch in the upper end of the z-drive.
This upper drive can be fitted with several different lower gearcases to satisfy different
boat applications. Refinements in the drive-line compliance have the opportunity to
slightly improve the noise, vibration, and harshness characteristics of this base model.
This same z-drive will be fitted with a wet disk master clutch on the engine for
decoupling drive torque during shifting in a premium version of this product. This
product retains all of the safety, reliability, and durability attributes of the dog clutch
while providing greatly improved noise, vibration, and harshness characteristics during
shifting. This design strategy molds ideas 2 and 4 of the VA / VE into one modular
approach. This design selection maintains cost competitiveness in the base product while
providing superior aesthetics in the premium product at a higher cost.
Page 10 of 32
It is recommended that system models be created and for the modular z-drive. These
models should then be analyzed for shift characteristics. It is also recommended that a
prototype modular z-drive be built and tested in the dog clutch only configuration and in
the wet disk master clutch and dog gear selector styles. Cost information has been based
on manufacturing engineering, and product engineering estimations to this point. A more
detailed cost study of the shift system is recommended in conjunction with the more
detailed design models and prototype. This will improve the accuracy of the value studies
conducted. This activity can be completed with the current new drive engineering team
and budget before December 17, 2004.
Page 11 of 32
Appendix A
Benchmark Study
Mercury Marine Clutch Type Benchmark
Dog Clutch
3/03/04 – 4/07/04
Participants: Phillip Magee, Tom Yerby
Ken Grainger, Robert Grantham
The objective of this benchmarking exercise is to form a list of clutches that are available
for use and are readily adaptable to the sterndrive system. This benchmarking aids in
providing a list of clutch types, their applications, and means of actuation.
Dog Clutch
Internal (Mercury Marine)
Product
Alpha Sterndrive
MC II Drive
215 E Drive
0-Drive
All Outboards
Application
Primary Clutch
Primary Clutch
Gear Selector
Primary Clutch
Primary Clutch
Actuation
Mechanical
Mechanical
Electric
Mechanical
Mechanical
Industry (Recreational / Light Commercial Marine)
Product
Application
OMC Drive
Primary Clutch
All Outboards
Primary Clutch
Konrad Drive
Primary Clutch
GLM Drive
Primary Clutch
Actuation
Mechanical
Mechanical
Mechanical
Mechanical
Functional (Automotive / Off Highway)
Product
Agricultural
Oil Well Pulling Unit Safety Brake
Auto. Performance Transmissions
Application
Various – low speed
Secondary Brake
Gear Selector
Actuation
Mechanical
Mechanical
Mech. / Elec.
Application
Primary Clutch
Actuation
Mechanical
Industry (Recreational / Light Commercial Marine)
Product
Application
Volvo Sterndrives
Primary Clutch
Yamaha Sterndrives
Primary Clutch
OMC Cobra
Primary Clutch
Actuation
Mechanical
Mechanical
Mechanica
Cone Clutch
Internal (Mercury Marine)
Product
Bravo Sterndrive
Functional (Automotive / Off Highway)
None
Page 12 of 32
Wet Disk
Internal (Mercury Marine)
Product
TR Sterndrive
Inboard Trans.
Six Drive Trans.
Application
Primary Clutch
Primary Clutch
Primary Clutch
Actuation
Hydraulic
Hydraulic
Hydraulic
Industry (Recreational / Light Commercial Marine)
Product
Application
Yamaha Sterndrive
Primary Clutch
BMW Sterndrive
Primary Clutch
All Inboard Trans.
Primary Clutch
Actuation
Hydraulic
Mechanical
Hydraulic
Functional (Automotive / Off Highway)
Product
Automated Planetary
Lay Shaft Transmissions.
Application
Primary Clutch
Primary Clutch
Actuation
Hydraulic
Hydraulic
Application
Primary Clutch
Actuation
Electric
Dry Disk
Internal (Mercury Marine)
Product
215 E Sterndrive
Industry (Recreational / Light Commercial Marine)
None
Functional (Automotive / Off Highway)
Product
Manual
Automated Manual Transmissions
Application
Primary Clutch
Primary Clutch
Actuation
Mech. / Hyd.
Hydraulic
Internal (Mercury Marine)
Product
TR Sterndrive
Application
Reverse Clutch
Actuation
Hydraulic
Industry (Recreational / Light Commercial Marine)
Product
Application
Chris Craft Inboard Trans.
Reverse Clutch
Actuation
Hydraulic
Functional (Automotive / Off Highway)
Product
Automated Planetary
Constant Velocity Transmissions
Actuation
Hydraulic
Hydraulic
Band
Application
Primary Clutch
Primary Clutch
Page 13 of 32
Centrifugal Clutch
Internal (Mercury Marine)
Product
None
Application
Actuation
Industry (Recreational / Light Commercial Marine)
Product
Application
None
Actuation
Functional (Automotive / Off Highway)
Product
Go Cart / Snowmobile
Application
Primary Clutch
Actuation
Mechanical
Page 14 of 32
Appendix B
Energy Trace and Barriers Diagram
Charlie
Item #
1
2
3
4
5
6
7
8
9
Desc.
Accessory Drive System
Flywheel
Universal Joint
Upper Gearset
Clutch
Vertical Drive Sahfts
Lower Gearset
Propeller Shaft
Propeller
Energy
Mechanical -Rotational
Mechanical -Rotational
Mechanical -Rotational
Mechanical -Rotational
Mechanical -Rotational
Mechanical -Rotational
Mechanical -Rotational
Mechanical -Rotational
Mechanical -Rotational
Delta
When Engine is Running
When Engine is Running
When Engine is Running
When Engine is Running
When Activated F/R
When Activated F/R
When Activated F/R
When Activated F/R
When Activated F/R
Barrier
Hatch
Hatch - Flywheel Housing
Hatch - Bellows
Drive Shaft Housing
Drive Shaft Housing
Drive Shaft Housing - Gearcase
Gearcase
Gearcase - Propeller
None
Page 15 of 32
Appendix C
Preliminary Hazard List
Preliminary Hazard List - Clutch Activation
Item #
1
Failure
Clutch Failure
a
To Forward
b
To Neutral
c
To Reverse
Page 16 of 32
Appendix D
Preliminary Hazard Analysis
Performed
Before/After
Design Made? (underline
POTENTIAL FAILURE MODE AND EFFECTS ANALYSIS (System)
one)
TITLE: Generic Clutch
MODEL: Sterndrive
CORE TEAM: Phillip Magee, Dennsi Gunderson, Paul Govek, Woody Smith, Ken Grainger, Rich
Todhunter, Manish Kulkarni, Kieth Schmidt, John Behara
PROJECT: New Sterndrive
ITEM/
POTENTIAL
POTENTIAL
S
POTENTIAL CAUSE(S) O
FUNCTION
FAILURE
EFFECT(S)
E
MECHANISM(S) OF C
MODE
OF FAILURE
V
FAILURE
C
CLUTCH
FMEA DATE:
TEAM LEADER:
FACILITATOR:
03/18/2004
Tom Yerby
Paul Govek
Full Attendance?
CURRENT
DESIGN
VALIDATION
Y N (underline one)
D R RECOMMENDED
E P
ACTION(S)
T N
TRANSMIT
TORQUE/
ROTATION
CLUTCH DESIGN
2
SPECIFICATION - TORQUE
CAPACITY REQUIREMENT
-HISTORY
2
-BOATING & NONBOATING INDUSTRY
STDS
-MODELING
-DESIGN ANALYSIS
-COMPONENT TESTING
-SYSTEM LEVEL TESTING
32
CLUTCH DESIGN
SPECIFICATION
4
-HISTORY
3
-BOATING & NONBOATING INDUSTRY
STDS
-MODELING
-DESIGN ANALYSIS
-COMPONENT TESTING
-SYSTEM LEVEL TESTING
120 EVALUATE
CONCEPTS
CONNECTION,
ACTUATION, & CLUTCH
DESIGN SPECIFICATIONS
4
-HISTORY
3
-BOATING & NONBOATING INDUSTRY
STDS
-MODELING
-DESIGN ANALYSIS
-COMPONENT TESTING
-SYSTEM LEVEL TESTING
120 EVALUATE
CONCEPTS
ACTUATION & CLUTCH
DESIGN SPECIFICATIONS
4
-HISTORY
3
-BOATING & NONBOATING INDUSTRY
STDS
-MODELING
-DESIGN ANALYSIS
-COMPONENT TESTING
-SYSTEM LEVEL TESTING
120 EVALUATE
CONCEPTS
INADEQUATE OR
NO BOAT MOVEMENT
DECREASING ABILITY
TO TRANSMIT
TORQUE/ ROTATION
ENGINE OVERREV
EXCESS HEAT IN CLUTCH
SYSTEM
NOT TRANSMIT
TORQUE/
ROTATION
RECEIVE/
TOLERATE
SIGNAL LOAD
TOLERATE
ACTUATION
THRUST FORCE
TRANSMITS TORQUE/ CONTINUOUS BOAT
ROTATION
MOVEMENT
DOES NOT RECEIVE/
TOLERATE SIGNAL
LOAD
8
7
6
10
ENGINE NO START
8
CONTINUOUS BOAT
MOVEMENT
10
NO SHIFT
ENGINE NO START
ENGINE OVERREV
9
8
7
DOES NOT TOLERATE CONTINUOUS BOAT
ACTUATION THRUST MOVEMENT
FORCE
NO SHIFT
ENGINE NO START
ENGINE OVERREV
NA
10
9
8
7
Page 17 of 32
Performed
Before/After
Design Made? (underline
POTENTIAL FAILURE MODE AND EFFECTS ANALYSIS (System)
one)
TITLE: Generic Clutch
MODEL: Sterndrive
CORE TEAM: Phillip Magee, Dennsi Gunderson, Paul Govek, Woody Smith, Ken Grainger, Rich
Todhunter, Manish Kulkarni, Kieth Schmidt, John Behara
PROJECT: New Sterndrive
ITEM/
POTENTIAL
POTENTIAL
S
POTENTIAL CAUSE(S) O
FUNCTION
FAILURE
EFFECT(S)
E
MECHANISM(S) OF C
MODE
OF FAILURE
V
FAILURE
C
CLUTCH
FMEA DATE:
TEAM LEADER:
FACILITATOR:
03/18/2004
Tom Yerby
Paul Govek
Full Attendance?
CURRENT
DESIGN
VALIDATION
Y N (underline one)
D R RECOMMENDED
E P
ACTION(S)
T N
TOLERATE
TORSIONAL
SHOCK &
VIBRATION
2
-HISTORY
2
-BOATING & NONBOATING INDUSTRY
STDS
-MODELING
-DESIGN ANALYSIS
-COMPONENT TESTING
-SYSTEM LEVEL TESTING
32
NA
NA
ABSORB/
DAMPEN
TORSIONAL
SHOCK LOAD
DOES NOT TOLERATE NO BOAT MOVEMENT
TORSIONAL SHOCK &
VIBRATION
INADEQUATELY
ABSORB/ DAMPEN
TORSIONAL SHOCK
LOAD
DISSIPATE HEAT INADEQUATELY
DISSIPATES HEAT
8
CLUTCH DESIGN
SPECIFICATION - NVH &
TORSIONAL SHOCK
CAPACITY & LIFE
REQUIREMENT
ENGINE OVERREV
EXCESS HEAT IN CLUTCH
SYSTEM
7
6
EXCESS NOISE &
VIBRATION
4
CLUTCH DESIGN
2
SPECIFICATION - NVH &
TORSIONAL SHOCK
CAPACITY REQUIREMENT
-HISTORY
2
-BOATING & NONBOATING INDUSTRY
STDS
-MODELING
-DESIGN ANALYSIS
-COMPONENT TESTING
-SYSTEM LEVEL TESTING
16
CONTINUOUS BOAT
MOVEMENT
10
CLUTCH DESIGN
SPECIFICATIONS
-HISTORY
3
-BOATING & NONBOATING INDUSTRY
STDS
-MODELING
-DESIGN ANALYSIS
-COMPONENT TESTING
-SYSTEM LEVEL TESTING
120 EVALUATE
CONCEPTS
NO SHIFT
ENGINE NO START
ENGINE OVERREV
9
8
7
4
Page 18 of 32
FMEA – Dog, Cone, Wet Disk, Dry Disk, Band Clutch
Dog
Same as generic clutch except (“Not
Transmit Torque / Rotation” failure
mode is scored as low potential)
Cone
Same as generic clutch
Wet Disk
Same as generic clutch
Dry Disk
Same as generic clutch
Band
Same as generic clutch
Page 19 of 32
Appendix E
Decision Analysis
New Drive Shift System VA / VE
1
4/7/2004
Value Analysis / Value Engineering
Process:
Project Definition
Function Worksheet
Function Analysis
Brainstorming Designs
Brainstorming Designs
T - Chart
Paired Comparison Matrix
Idea Selection Worksheet
Attendance:
Invited
Tom Yerby
Dennis Gunderson
PhillIp Magee
Lawrence Robinson
Rod Caldwell
Manish Kulkarni
Keith Schmidt
Darrin Doty
Bob Burrell
John Behara
Chad Martin
Rich Todhunter
Craig Armstrong
Woody Smith
Larry Miller
Ken Grainger
Paul Govek
Robert Grantham
Dept.
Eng.
Eng.
Eng.
Eng.
Eng.
Eng.
Eng.
Eng.
Eng.
Eng.
Integration
Integration
Mfg. Eng.
Mfg. Eng.
Quality
Service
Eng.
Marketing
Go Over Product Plan
Verb - Noun Function List
Organize Function List
Let Creativity Flow (not Flood)
Sort Out Top 3 or 4 Designs
Pro's and Con's of Top 3 or 4
Pick Rating Criteria
Score Top 3 or 4 Designs.
Participants
Dennis Gunderson
Phillip Magee
Mark McCartor
Rod Caldwell
Manish Kulkarni
Keith Schmidt
Bob Burrell
John Behara
Randy Stokes
Robert Grantham
Page 20 of 32
Rules
2
Decisions
Type
Command - Quick , Based on Judgment and Intelligence of Decision Maker
Consensus - Teamwork, Requires Cooperation, Based on Judgment and Intelligence of the Team
We plan to consider all input during this VA / VE session but will quickly move through decisions based
on MAJORITY RULES consensus decisions.
Brainstorming
No ideas are evaluated during the brainstorming session. No criticism.
Say It - Write It - Toss It
Get Creative
Page 21 of 32
PROJECT:
3
New sterndrive
PROJECT TYPE:
Design
OBJECTIVES:
Select shift system type or types and configuration
SCOPE:
New sterndrive or drives will replace current Alpha and Bravo sterndrives
Design primarily between engine and propeller
New design may effect engine controls (electronics)
New design may effect shift actuation system (control handle and linkages)
SCOPE DOES NOT INCLUDE:
Engine
Propellers
COST:
Targets not officially set
Known:
Alpha replacement product is cost sensitive
Bravo replacement product is less cost sensitive and more aesthetically sensitive
Page 22 of 32
Function Worksheet
4
Verb
Noun
Type
Transmit
Transmit
Decouple
Decouple
Receive
Tolerate
Dissipate
Absorb
Engage
Tolerate
Torque
Rotation
Torque
Rotation
Signal
Signal
Heat
Torsional Shock
Mating Face
Engagement
B
B
B
B
B
R
R
R
B
R
Types of Functions
B - Basic
HO - Higher Order
Specifications / Comment
vibration / impact
R - Required Secondary
A - Asthetic Secondary
U - Unwanted Secondary
Page 23 of 32
Function Analysis System Technique Diagram
Verb
Noun
Verb
5
Noun
How
Why
H.O Func.
Assumed Func.
Basic Function
Transmit Rotation Engage
Decouple Rotation
Mating Face
Receive
Signal Transmit Torque
Decouple Torque
Req'd Secondary Function
Tolerate Engagement
Tolerate Signal
Dissipate Heat
Absorb
Torsional Shock
Page 24 of 32
New Sterndrive
6
Brainstorming
Idea # Description
1 Cone Clutch
2 Dog Clutch
3 Synchronized Toothed / Dog
4 Wet Disk Clutch
5 Dry Disk Clutch
6 Magnetic Clutch
7 Band Clutch
8 Belt (w Slip for Neutral)
9 Centrifugal
10 Sprag
11 Spring Clutch
12 Lock -Up Torque Converter with Disk Brake for Neutral
Page 25 of 32
New Sterndrive
7
Brainstorming
Idea # Description
1
2
3
4
5
6
7
Cone Clutch (Bravo Style)
Dog Clutch (Alpha Style)
Synchronized Toothed / Dog (w 2 Stage Engine Coupler)
Wet Disk Master Clutch (On Eng.) / Dog Gear Selector ( In Drive)
Wet Disk Synchronized Dog Master Clutch (On Eng.) / Dog Gear Selector (In Drive)
Dry Disk Master Clutch (On Eng.) / Cone Clutch Gear Selector (In Drive)
Torque Converter (On Eng.) / Cone Clutch Gear Selector (In Drive)
Page 26 of 32
VAVE: New Sterndrive
8
Cone Clutch (Bravo Style)
+
Proven technology
Compact
High capacity
Limp Home
Moderate cost
Durable
Moderate NVH
-
High actuation force
Sensitive to actuation force
Sensitive to tolerances
Difficult to measure
Sensitive to finish
Moderate NVH
Fails in closed position
Temperature sensitive
Sensitive to contamination
What Can Be Done
Self actuate
Monitor finish
Page 27 of 32
VAVE: New Sterndrive
9
Dog Clutch (Alpha Style)
+
Durable
Robust
Compact
Clutch and selector
Low cost
Simplistic
Proven technology
Ratchetablity
Fails open
Tolerable to contamination
-
Loud
Harsh
Abrupt
Actuation time sensitive
Old technology
No limp home
What Can Be Done
2 stage eng. coupler
2 stage eng. coupler
2 stage eng. coupler
Use with newer tech.
sychronizeres,
couplings, clutches
Page 28 of 32
VAVE: New Sterndrive
10
Synchronized Toothed / Dog (w 2 Stage Engine Coupler)
+
Simple
Proven technology
Automotive
application
-
What Can Be Done
No ratchetability
Not proven in
marine Appl.
Complex assy.
More components
Moderately compact than dog / cone
NVH better than dog
/ cone
Temp. sensitive
No limp home
Less reliable than
dog
Page 29 of 32
VAVE: New Sterndrive
11
Wet Disk Master Clutch (On Eng.) / Dog Gear Selector ( In Drive)
+
Perfect NVH
Temperature tolerant
Limp home
Dog fails open
-
What Can Be Done
Increased
complexity
Increased cost
Lower reliability
No water pump in
drive
Requires hydraulic
pump
Page 30 of 32
Eval. Criteria
A
Decision
New Sterndrive
Reliability (Must)
Durability Envir./Time/Cycles (Must)
Serviceability / Maintenance (Want)
MFG. Mach. / Assy. (Want)
Safety (Must)
Packaging (Want)
NVH (Want)
Styling (Want)
A
B
A
B
C
A
B
C
D
E
E
E
E
E
A
B
F
F
E
F
A
B
G
G
E
G
G
A
B
C
D
E
F
G
H
I
6
5
2
1
7
3
4
0
0
100
21.4
17.9
7.1
3.6
25.0
10.7
14.3
0.0
0.0
12
Total Rating %
28
Page 31 of 32
13
#
Evaluation Criteria
Weight
1 Reliability (Must)
21.43
2 Durability Envir./Time/Cycles (Must)
17.86
3 Serviceability / Maintenance (Want)
7.14
4 MFG. Mach. / Assy. (Want)
3.57
5 Safety (Must)
25.00
6 Packaging (Want)
10.71
7 NVH (Want)
14.29
8 Styling (Want)
9
0.00
0
Total Weighted Criteria
Estimated Cost
Value Ratio
Criteria/Cost
Idea 1
6
128.6
7
125.0
9
64.3
6
21.4
6
150
9
96.4
6
85.7
0
0
Idea 2
Idea 3
9
192.9
9
160.7
9
64.3
9
32.1
8
200
9
96.4
3
42.9
0
0
4
85.7
6
107.1
8
57.1
4
14.3
6
150
7
75.0
7
100.0
0
0
Idea 4
5
107.1
9
160.7
6
42.9
5
17.9
8
200
5
53.6
10
142.9
0
0
0.00
100
0
671.4
$100.00
6.7
0
0
0
789.3
589.3
725.0
$50.00 $120.00 $170.00
15.8
4.9
4.3
Page 32 of 32