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International Journal of Automotive Technology

, Volume 20, Issue 1, pp 147–156 | Cite as

Novel Self-Clamping Clutch Mechanism for Micro Electric Vehicle Transmission

  • Seung-uk Park
  • Kyung-woong KimEmail author
  • Byung-chul Na
  • Jin-yong Kim
Article
  • 2 Downloads

Abstract

This paper deals with a novel clutch mechanism for transmission applications, which aims at easy application of the transmission as the micro-electric vehicle models expand in variety. The new mechanism actuated by the torque and rotational inertia of the traction motor instead of the conventional hydraulic or electronic actuator and features a simple structure compared to the conventional mechanism. The operating principle, structure and mathematical modeling of the new clutch mechanism are presented, and verification of mathematical modeling was done through comparison of experimrntal and analytical results. To investigate the automotive suitability of the new clutch mechanism, the shift characteristics are analyzed by longitudinal directional vehicle dynamic model applying new clutch mechanism. As a result of the analysis, it was confirmed that the shift shock absorbing ability and required time for shifting are applicable to the vehicle transmission.

Key words

Self clamping Clutch mechanism Electric vehicle Transmission Shift shock absorbing 

Nomenclature

Av

front projected area of the vehicle

CD

damping coefficient of the clutch shock absorber

CR

rolling resistance coefficient

CT

damping coefficient of the tire

F

force acting perpendicular to the tooth surface of the worm

Fn

worm lead angular component of the axial component of F

Fa

Axial component of force acting on tooth surface.

Ft

pitch circle tangential component of force acting on tooth surface

Ji

moment of inertia of the power input part

Jo

moment of inertia of the power output part

Jm

moment of inertia of traction motor

Jgm

moment of inertia of gear gm

JL1

moment of inertia of gear L1

JH1

moment of inertia of gear H1

Jgf

moment of inertia of gear gf

JL2

moment of inertia of gear L2

JH2

moment of inertia of gear H2

JD

moment of inertia of differential gear case

JW

moment of inertia of the rim, half drive shaft and half tire

Jv

moment of inertia of vehicle equivalent rotational mass

KC

torsional stiffness of the clutch mechanism

KR

coefficient of virtual rotation spring

Kl

coefficient of clutch disk clamping spring

KD

stiffness of the clutch shock absorber

KH

stiffness of the drive shaft

Km

stiffness of the motor shaft

KT

stiffness of the tire

KRH

virtual torsion spring coefficient of clutch mechanism CH

KRL

virtual torsion spring coefficient of clutch mechanism CL

SD

air resistence coefficient

Ti

torque acting on the power input part

To

torque acting on the power output part

Tc

transmitted torque by clutch mechanism

Tcc

transmitted torque by friction clutch disk

Tcw

transmitted torque by worm tooth contact

Tm

input torque of traction motor

TCL

transmitted torque through clutch mechanism CL

TCH

transmitted torque through clutch mechanism CH

Tv

running resistance torque applied to the vehicle wheel

a

road slope angle

mv

vehicle mass

p

relative angular displacement of the clutch mechanism at stick condition

rc

effective radius of friction clutch

rw

pitch circle radius of worm

rt

tire radius

α

worm lead angle

β

torsional damping coefficient of the clutch mechanism

ϕi

angular displacement of power input part

ϕo

angular displacement of power output part

ϕR

relative angular displacement of power input/output part

ϕT

maximum elastic deformation angle in the rotational direction of the clutch mechanism

ψ

pressure angle of worm tooth

μc

friction coefficient of clutch disk multiplied by contact surface number

μw

friction coefficient of worm & worm gear contact surface

γL1

ratio of radius of gear gm and gear L1

γH1

ratio of radius of gear gm and gear H1

γL2

ratio of radius of gear gf and gear L2

γH2

ratio of radius of gear gf and gear H2

ϕm

angular displacement of traction motor

ϕgm

angular displacement of gear gm

ϕgf

angular displacement of gear gf

ϕD

angular displacement of differential gear case

ϕW

angular displacement of rim

ϕv

angular displacement of tire

ϕrL

relative angular displacement of power input/output part of clutch mechanism CL

ϕrH

relative angular displacement of power input/output part of clutch mechanism CH

ρair

air density

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References

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Copyright information

© The Korean Society of Automotive Engineers and Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Seung-uk Park
    • 1
    • 2
  • Kyung-woong Kim
    • 1
    Email author
  • Byung-chul Na
    • 2
  • Jin-yong Kim
    • 2
  1. 1.School of Mechanical, Aerospace & System EngineeringKAISTDaejeonKorea
  2. 2.Energy System R&D CenterKorea Automotive Technology InstituteChungnamKorea

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