Development of 3-D simulation for power transmitting analysis of CVT driven by dry hybrid V-belt - PowerPoint PPT Presentation

Development of 3 d simulation for power transmitting analysis of cvt driven by dry hybrid v belt l.jpg
Download
1 / 22

Development of 3-D simulation for power transmitting analysis of CVT driven by dry hybrid V-belt. International Continuously Variable and Hybrid Transmission Congress September 23-25, 2004 San Francisco, CA. Masahide FUJITA Hisayasu MURAKAMI

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Download Presentation

Development of 3-D simulation for power transmitting analysis of CVT driven by dry hybrid V-belt

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Development of 3 d simulation for power transmitting analysis of cvt driven by dry hybrid v belt l.jpg

Development of 3-D simulation for power transmitting analysis of CVT driven by dry hybrid V-belt

International Continuously Variableand Hybrid Transmission Congress

September 23-25, 2004

San Francisco, CA

Masahide FUJITA Hisayasu MURAKAMI

Power Train Research and Development DivisionDaihatsu Motor CO., LTD.

Shigeki OKUNO Mitsuhiko TAKAHASHI

Power Transmission Technical Research Center

Bando Chemical Industries, LTD


Contents l.jpg

Contents

  • Background

  • New CVT

  • 3D-simulation

  • Outcomes

    • Transmitting efficiency

    • Dynamic strain on the belt

  • Conclusions


Background l.jpg

Main products of Daihatsu: Small-sized Cars

Background

Application

New CVT

Commercialized CVT

Metal pushing V-belt

Excessive quality

Dry hybrid V-belt

1L2L

Higher efficiency

Engine displacement


New cvt with dry hybrid v belt l.jpg

New CVT with Dry Hybrid V-belt

Advantage:

Air cooling

No lubricant

=Higher efficiency

High torque capacity with improved wider belt

=Increased belt mass / inertia

Tension bands

Blocks (Resin coated aluminum alloy)

Aramid cord

Rubber


New cvt system l.jpg

Merit

Increase contact angle

Torque capacity rise

Belt tension control

Better efficiency

New CVT system

  • Demerit

    • Reverse bending force

      • Less durability

Tension Pulley

Driven Pulley

Driving Pulley


3 d dynamic simulation l.jpg

3-D dynamic simulation

Belt movement in high speed:

Dynamic measurementsisimpossible

3-D dynamic FEA is needed

Driven Pulley

Driving Pulley

3800rpm

30m/s


Selection of fem code l.jpg

Required features:

Precise inertia force calculation

Advanced contact search

Dynamic belt behavior visualization (stress & others)

Explicit FEM code

ESI Software's PAM-MEDYSA(MEchanical DYnamic Stress Analysis)

Selection of FEM code


Modeling of dry hybrid v belt l.jpg

Building the model as it is

Cord anisotropy

Contacts defined between block & tension band

Modeling of dry hybrid V-belt

Block

Resin

Rubber

Upperbeam

Tension band

Lowerbeam

Cord

Aluminum


Modeling of cvt pulleys l.jpg

All parts: Defined aselastic

Components of pulley shaft

Sliding interface taking account of shaft clearance

Modeling of CVT pulleys

Fixed pulley

Movable pulley

Slide keys

Fixed pulley shaft

w/ clearance

Resin bush


Calculation procedures l.jpg

Initial state (Belt: Tension free)

Move driving pulley (apply tension to the belt)

Rotate driving pulleyApply absorbing torque

Calculation procedures

Driving pulley

Driven pulley


Calculation procedures movie l.jpg

Calculation procedures: movie


Outcome on initial model l.jpg

Outcome on initial model

Transmitting efficiency

At high speed running: lower efficiency

Difference (simulation/experiment): 2%

100

99

98

Efficiency(%)

97

96

95

94

0

10

20

30

40

Belt velocity (m/s)

Ratio: High (0.407) Input torque: 80Nm

Calculated

Measured

All Parts:elastic

2%


Outcome from improved model l.jpg

Matching of simulation with measurement

Solutions:

Take account offriction loss at pulley shaft

Increase friction loss between belt and pulleys

Outcome from improved model

Ratio: High (0.407) Input torque: 80Nm

Calculated

Movable

pulley

Measured

Slide keys

Fixed

pulley

Pulley shaft

w/ clearance

Resin bush


Permanent deformation of tension band l.jpg

Permanent deformation of tension band

From heat aging

Clearancebetween tension band and block

=

At final period of belt lifespan:

  • Decrease transmitting efficiency

  • Belt temperature rise


Effect of permanent deformation l.jpg

Effect of permanent deformation

power loss +18 %

1.45kw

1.72kw

Vehicle speed

60Km/h

with belt speed 30m/s

with belt speed 35m/s

Final period

of lifespan

Calculation result of clearance vs. transmitting efficiency


Effect of permanent deformation16 l.jpg

At high speed range

Increase clearance

Decrease efficiency

Efficiency lowed within 1%

Power loss +18%

Belt temperature rise

Effect of permanent deformation


Dynamic strain analysis l.jpg

At the period of lifespan

Crack at lower sideof tension bands

Dynamic FEA

Calculate lower side strainat higher belt speed

Dynamic strain analysis

crack


Strain peak at tension pulley l.jpg

Strain peak at tension pulley

Period of contact with tension Pulley

Strain Peak in dynamic behavior

Ratio:High (0.407)Low (2.449)

Strain

Bending

Strain

0

Belt speed: 35m/s 9.7m/s


Strain analysis at tension pulley l.jpg

Strain analysis at tension pulley

Strain by dynamic behavior

proportional to Belt Speed squared

12

11

10

9

8

7

6

下コグ表面歪み(%)

5

4

3

2

1

0

0

5

10

15

20

25

30

35

40

ベルト速度(m/s)

Strain in dynamic behavior

calculated strain

Tension band strain(%)

Bending strain

S=0.00177*V2+7.96

Belt speed(m/s)


Crack failure s n curve l.jpg

Crack failure S-N curve

Belt temperature rise

Strain (%)

Belt speed increase

Number of cycles to crack


Prediction of belt life l.jpg

Based on S-N curve and calculated strain

Full agreement

Decrease velocitylonger belt life

Prediction of belt life

Belt temperature :130deg C

Experiment

Calculated

Experiment

Calculated

35m/s

30m/s


Conclusions l.jpg

Factors to affect transmitting efficiency:

Pulley shaft clearance

Permanent deformation of tension band

Friction loss = Lower efficiency at high belt speed

Raise belt temperature

Shorten belt life

Dynamic strain at high belt speed

Shorten belt life

Keys to success

Cooling system

Limit the maximum belt speed

Conclusions


  • Login