DFM Oil Pump Project Stanford

03/13/2012previous next

GM of MexicoRamos Arizpe Complex

June 2000

ME217 Design for Manufacturability

Stanford University

1

Improved Oil Pump System for the 4L60-E Transmission

Final Presentation - ME217B

Paulino Rivera Carlos B. Ramirez Fernando J. Valdes

The Pumpkins

Tuesday, March 13, 2012



June 2000


Stanford University

2

Project Advertisement

BackgroundProduct Definition

Design Recommendation

Competitive Analysis

Concept Development

Introduction




June 2000


Stanford University

3

Market & Competition

• GM’s transmissions have a rich tradition of excellence

• GM Powertrain dominates the Automatic Transmisison business, with 43% share, Ford 29%, DC 28%

• 4L60-E Automatic Transmission Produced in Ramos Arizpe since 1999

• Applications: Suburban, Tahoe, Yukon, C/K (domestic and export)




Concept Development

Introduction




June 2000


Stanford University

4

Problem Statement

• The oil pump system is critical for the performance of the transmission

• A large number of transmission failures are associated with the oil pump

• Goal of this project:

Improve the Reliability of the 4L60-E Oil Pump System, while reducing its cost




Concept Development

Introduction




June 2000


Stanford University

5

Product Definition - ME217A

• Edith Wilson’s Checklist Improved• 4L60-E Pump Benchmarked vs. Ford and DaimlerChrysler Transmissions

• CVCA showed multiple customers

Background

Product Definition



Concept Development

Introduction

35 4 2




June 2000


Stanford University

6

Key Relationships• Value Graph: showed importance of two key internal components: Rotor and Slide

• QFD Phase I: showed DPTV’s and End Clearance as highest relative E.M.’s

• QFD Phase II: Rotor, Pump Body & Slide most important

• Cost-Worth identified candidates for:• Cost Reduction: Cover & Shaft, Pump

Body• Enhancement: Rotor, Slide, Slide

Springs




Concept Development

Introduction




June 2000


Stanford University

7

Function-Structure Tree• Revealed Product Complexity: functions

not related to the Pump Oil main function

1. Displace fluid 2. Regulate fluid 3. Provide structure

• Seal• Support

• Most Important Discovery in ME217A




Concept Development

Introduction




June 2000


Stanford University

8

Pareto was right...

• Fishbone Diagram and DFA showed redundancy in Rotor/Slide selection process

• FMEA revealed Rotor/Slide Stucked as main cause of oil

pump failure

• SMA: easier to replace entire oil pump than to service

0

125

250

375

500

Rot

or/S

lide

Stu

cked

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arts

Pum

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ody

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on

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ility

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ks

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over

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re

Eng

ine

Inpu

t Spe

ed H

igh

0

0.250

0.500

0.750

1.000

CAUSE

70%




Concept Development

Introduction




June 2000


Stanford University

9

Concept Development

• Design Criteria expanded from QFD:

• Morphological Analysis generated 3 concepts: Single Slide/Rotor, Pump-in-a Box and Three-in-One Pump




Concept Development

Introduction




June 2000


Stanford University

10

Three-In-One Pump• Pugh Analysis revealed as better concept

• Improved: Reliability, FTY, DPTV, Robust Design, Performance

• Use of a Single Slide/Rotor (5 to 1)




Concept Development

Introduction

COVER & SHAFT

PUMPSUPPORT

CASE COVER

SUPPORT COMPONENTS

PUMP OIL

SEAL TRANSMISSION




June 2000


Stanford University

11

Current vs Proposed

CURRENT

COVER & SHAFT

PUMP BODY

3 in 1 Concept

COVER & SHAFT

PUMPSUPPORT

CASE COVER




Concept Development

Introduction




June 2000


Stanford University

12

Product Specification• Same size than current oil pump• Weight assumed unchanged • Case Cover error proofed for alignment• Case Cover made of Aluminum SAE 390

Process Specification• Sub-Assembly: one machine less (Rotor/Slide),

one worker reduced, fixtures error proofed• Machining: Pump Support line from existing

PumpBody cell, addition of Case Cover cell, lean manufacturing, error proofing devices, no impact in labor





Concept Development

Introduction




June 2000


Stanford University

13


• Business Case• Payback: 1 Year• ROI: 94.6%• Investment: $ 2.12 MUSD• NPV: $ 2.22 MUDS

• Development Time• 18 months from project approval

• Risks• Envisioning: limited product life• Design: packaging within envelope, same weight• Execution: material cost increase, validation fails




Concept Development

Introduction




June 2000


Stanford University

14

Quality Scorecarding

• Project Objective (Biggest Y)Improve the Net Present Value (NPV)

• Objective Measures (Y)Improve the Reliability measured in Defects per Thousand Vehicles (DPTV’s) and First Time Yield (FTY) in the assembly line.

• Control Factors (vital X’s)End clearance between the Rotor/Slide and Pump Support face, Pump Main Line Pressure.

• Noise Factors (V’s)Oil Pump Support distortion, manufacturing variation of Slide/Rotor/Pump Face.

• Transfer FunctionCashflow Analysis Spreadsheet




Concept Development

Introduction




June 2000


Stanford University

15

Conclusions and Recommendations

Conclusions • Robust Product Definition• Strong Business Case• Higher Risk: limited product life• Still profitable! (trucks)

Recommendations• Obtain management commitment• Form project team• Enhance communication• Keep focus on customer• Revisit dfM tools to measure results




Concept Development

Introduction




June 2000


Stanford University

16

QUESTIONS&

ANSWERS

Paulino Rivera Carlos B. Ramirez Fernando J. Valdes

The Pumpkins


DFM Oil Pump Project Stanford

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