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DYNAMIC SIMULATION OF AN INNOVATIVE

PERMANENTLY ENGAGED MECHANISM FOR

STARTING SYSTEMS

Authors:

Alvaro Canto MichelottiZEN S.A. Indústria Metalúrgica, Brusque (SC), Brazil.

Alvaro.michelotti@zensa.com.br

Jonny Carlos da SilvaUniversidade Federal de Santa Catarina (UFSC),

Florianópolis (SC), Brazil.

jonny.silva@ufsc.br

23rd ABCM International Congress of Mechanical Engineering

December 6-11, 2015, Rio de Janeiro, RJ, Brazil

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1. Introduction

2. Stop-Start Vehicles

3. Mechanical Interface for Starting Systems

4. Innovative DCS concept

5. Simulation Model

6. Results

7. Conclusions & Next Steps

Summary

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Alvaro Michelotti, M.Eng. – R&D Technical Specialist

Master degree in Mechanical Engineering – Univ. Federal de Santa Catarina (UFSC)

Doctorate (on-going) in Mechanical Engineering - UFSC

Research focus in Mechanical Systems, Lumped parameter Modeling & Simulation

Since 2003 works for ZEN S.A., in R&D area since 2012

+16 years of professional experience in the automotive market

Introduction - About the Author

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Annual carbon emissions from passenger vehicles are projected to climb +54% by 2030

Ref. Eichlseder & Wimmer (2005)

Upcoming technologies to replace current ICE (Fuel-Cell, Plug-in Electric and Hybrid)

New Technologies - infrastructure, fuel availability and cost level – Ref. Christidis (2003)

Continuity of ICE as the main propulsion system (Improved):

HCCI (Homogeneous Charge Compression Ignition), Carney (2008).

Engine Downsizing - DeCicco, et al. (2001)

Fuel Direct Injection - Leduc (2003)

IntroductionAutomotive Market Challenge

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Starting system remains basically the same for over a century

New Concepts => permanent connection by means of gear set or belt system

New requirements for SSV (Stop-Start Vehicles)

Potential SSV market share: 37 Mi in 2020 Ref. Pike Research (2012)

Objective:

propose and develop a new concept in Dynamic Coupling System (DCS), based on a permanently engaged connection between ICE and Starter Motor

IntroductionStarting Systems Evolution

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Stop Start Vehicles (SSV)Concept Overview

- Electronic Management SystemControls automatic stop and start of the ICE

- SSV 1st Generation:

To Shutdown engine:Vehicle is stationaryGear in neutralBattery has enough power for next engine start up... Any additional strategy

To turn engine back on:First gear engagedTemp inside vehicle...

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GR Starter PLGR Starter PMOSGR Starter

OSGR Starter

DD Starter

Main structure:

• Electric Starter Motor• Control systems (solenoid, relay, ...)• Battery• Wiring (control circuit, battery poles +/- )

Product design evolution / Application Specific

Stop Start Vehicles (SSV)Starting System Overview

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Starting failure (milling)Starting Engagement

Stop Start Vehicles (SSV)Starting System Overview

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Stop Start Vehicles (SSV)Dynamic Coupling System (DCS)

• Mechanical components

• Connecting Electric motor armatureto ICE crankshaft

• Power transmission

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Conventional Starter Improved Starter with Tamdem Solenoid

Permanently Engaged Starter

Belt Starter/Alternator (BAS)

Stop Start Vehicles (SSV)DCS Generic Types

PES – wet sprag clutch inside engine block PES – dry sprag clutch in

flywheel

Patent search

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New DCS Concept

Ring gear with internal or external gear teeth profile (1)

ICE flywheel (2)

Pinion gear (3) fixed in the armature shaft of the electric starter motor (4)

Permanently Engaged System between internal gear (5) and pinion (3)

Ring gear (1) has also na external ratchet or wedge profile (6)

Ratchet profile to engage to one or more pawls or mechanical diodes (7)

Pawl mounted in the flywheel subsystem (2) of the ICE crankshaft (8)

Damping system – CRITICAL DESIGN VARIABLE

Patent pending design in 2012 (INPI BR102012029979-8)

Patent Application

sketch

Innovative DCS Concept

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Subsystems

Assembly View

1) OWC Carrier System ( carrier / pawl / spring / pin)

2) Damping System ( arc springs / endstops / retainer / fasteners)

3) Flywheel System (Flywheel / Ring gear / Ratchet Profile / Bearing or Bushing)

4) Starter Motor Interface (armature shaft end / pinion)

Exploded View

Innovative DCS Concept - Subsystems / Components

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Innovative DCS Concept – Damping System

• Pawl-Ratchet OWC carrier (1) inside the flywheel (High Torque Capacity)

• Damping System for noise/vibration attenuation => arc springs (1) and carrier friction (2)

• Overrunning noise reduced by adjusted centrifugal effect and damping surface in pawl (3)

25

24

232122

20

1211

13

16

14

50

171840

(3)

(1)

(2)

Damping System for the Pawl-Ratchet OWC

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Simulation Model: Block Diagram

Fig 3 – Schematic of the Simulation Model for OWC damping performance

• Input / Output

• One-Way Clutch Model (simplified)

• Damping system effect in OWC

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Simulation Model: 1-D System

• 1st step: Lumped Parameter Sketch

• 2nd step: Mathmatical Models

• Model 1: OWC w/o damping system

• Model 2: OWC with damping system

(1)

(2)

Impulse = variation in quantity of movement

Pawl – Force (F) from torque TS;

TS => applied during t

Maximum distance X

Te to rotate flywheel (ICE crankshaft)

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• 3rd step: Parameter configuration

• 4th step: Simulation

• Simulation Results:

Simulation Results

CONCLUSION:with adjusted

damping system: 90% less impact

force!

12 kN peakimpact force

1.5 kN peakimpact force

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Proposed configuration

Current configuration

starter motor proposed changes:

lever – removed

solenoid plunger - removed

New positioning frame

Flywheel modification

Integrated OWC

Integrated damping system

Ring gear modification

Bearing support

External ratchet/wedge profile

Internal spur gear profile

Engine Test Bench VW EA111 – 1.6l/gasoline/4 cylValeo starter motor D7ES6

Current starter

Pinion - ModifiedModified Flywheel w/ ring gear

Experimental Results – Prototype Construction

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• DCS Prototype installed in ICE test bench

• Instrumentation (engine RPM)

• Succesful engine startup:

+100 starts during preliminary testing

• Noise evaluation:

DCS : 89 dB(A) max.

Conventional: 94 dB(A) max.

Experimental Results – Performance

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• Reduced starting cycle

DCS

~ 0.3s~ 0.8s

Conventional

Experimental Results – Cycle Time

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Aid of 1-D simulation to develop innovative products

Impact during engagement solved by a damping system => innovative DCS design

Experimental prototype confirmed system potential

NEXT STEPS:

Further refinement of the system – Durability targets

Both technical & economical validation of the system

Further research as a potential contribution to SSV emissions reduction

Conclusions & Further Research

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Thank you!

Alvaro Michelotti, M.Eng.R&D Technical Specialist

ZEN S.A.Alvaro.michelotti@zensa.com.br

Tel +55-47-3255-2899www.zensa.com.br