Search results for "Power split"
showing 4 items of 4 documents
Power losses in power-split CVTs: A fast black-box approximate method
2018
Abstract This paper addresses the mechanical losses of planetary transmissions, with particular attention to power-split CVTs in their hybrid electric versions. It provides unified layout-independent analytical relationships, which can be used for both analysis, design and control purposes, and a simplified approach; the latter overcomes the necessity to segment the operating range of the power-split CVT in order to keep its loss model physically consistent. An example of application to a real hybrid electric PS-CVT is performed to show the simplicity, accuracy and generality of the proposed method.
Parametrical design of Split-Way CVTs
2016
La presente attività di ricerca si svolge presso l’Università degli Studi di Palermo nell’ambito di un corso di dottorato in Ingegneria dell’Innovazione Tecnologica, il quale si pone l’obiettivo di delineare una procedura semplice, generale e modulare per la progettazione, la modellistica ed il dimensionamento di trasmissioni meccaniche innovative, eventualmente coadiuvate da dispositivi di accumulo d’energia. In particolare, una crescente sensibilità verso le problematiche connesse all’efficienza energetica, e la conseguente ascesa dell’auto ibrida, ha fatto sì che negli ultimi anni le trasmissioni di tipo Split-way suscitassero, specie in virtù della loro capacità di consentire un certo s…
Efficiency of Split-Way CVT's. A simplified model
2007
ABSTRACT In this paper, a general formula is obtained for the efficiency of all types of Split-Way CVT, consisting of one or two epicyclic trains, a number of fixed ratio gears and one variable speed unit (CVU). It is based on the application of the principle of virtual works and on the simplifying hypothesis that all the dissipation is lumped inside the CVU. The comparison with some experimental results from the literature shows a surprisingly good fit, also in the neighbourhoods of zero speed ratio. INTRODUCTION The possibility of changing the speed ratio continuously between the primary and the secondary shaft of a mechanical transmission is a very interesting topic, mainly in the automo…
Direct analysis of power-split CVTs: A unified method
2018
Abstract This paper provides a fast kinematic analysis method for compound power-split CVTs, which consents to identify their functional parameters. Such parameters permit the assessment of power flows, torques and efficiency, and the design of equivalent transmissions by the use of a recently published mathematical model. The same method can easily address either simpler or more complex transmissions by mean of kinematic equivalent parameters, without the need to arrange separate systems of equations. As a case study, we performed the kinematic analysis of the “Voltec” multi-mode GM transmission.