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Tribodynamics of a new declutch mechanism aimed for engine downsizing in off-road heavy-duty vehicles

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journal contribution
posted on 19.05.2017, 10:38 by Nader DolatabadiNader Dolatabadi, Ramin RahmaniRamin Rahmani, Stephanos TheodossiadesStephanos Theodossiades, Homer Rahnejat, Guy Blundell, Guillaume Bernard
Clutches are commonly utilised in passenger type and off-road heavy-duty vehicles to disconnect the engine from the driveline and other parasitic loads. In off-road heavy-duty vehicles, along with fuel efficiency start-up functionality at extended ambient conditions, such as low temperature and intake absolute pressure are crucial. Off-road vehicle manufacturers can overcome the parasitic loads in these conditions by oversizing the engine. Caterpillar Inc. as the pioneer in off-road technology has developed a novel clutch design to allow for engine downsizing while vehicle’s performance is not affected. The tribological behaviour of the clutch will be crucial to start engagement promptly and reach the maximum clutch capacity in the shortest possible time and smoothest way in terms of dynamics. A multi-body dynamics model of the clutch system is developed in MSC ADAMS. The flywheel is introducing the same speed and torque as the engine (represents the engine input to the clutch). The hydraulic pressure is applied behind the piston to initiate the engagement. The angular motion of the plates is supported by friction torque between the plates and friction linings. The conjunctions between paper-based linings and steel plates are designed to be dry. Friction (the most significant tribological feature of the linings in torque transmission) is measured in a pin-on-disc tribometer and mapped into the dynamics model in MSC ADAMS. The pin-on-disc tribometer is able to capture the variation of friction coefficient with contact pressure and sliding velocity. The surface topography is obtained experimentally to examine the consistency of surface properties. The normal pressure and tribology of the contacting components determines the engagement time, clutch capacity and dynamic behaviour of the clutch.

Funding

The authors wish to express their gratitude to the Innovate UK for the financial support extended to (EBD3) Declutch program Grant (TSB reference: 102249), under which this research was carried out. Thanks are also due to the consortium of industrial partners of the EBD3 project, particularly to Turner Powertrain and Perkins Engines Co Ltd (Subsidiaries of Caterpillar) in this instance.

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

SAE Technical Papers

Volume

2017-01-1835

Citation

DOLATABADI, N. ... et al, 2017. Tribodynamics of a new declutch mechanism aimed for engine downsizing in off-road heavy-duty vehicles. SAE Technical Paper 2017-01-1835.

Publisher

© SAE International

Version

AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Acceptance date

06/04/2017

Publication date

2017-06-05

Notes

This paper was accepted for publication in the SAE Technical Papers and the definitive published version is available at https://doi.org/10.4271/2017-01-1835

ISSN

0148-7191

Book series

SAE Technical Paper;2017-01-1835

Language

en

Location

Grand Rapids, Michigan, USA