Theoretical Model of Metal V-Belt Drives During Rapid Ratio Changing

1999 ◽  
Vol 123 (1) ◽  
pp. 111-117 ◽  
Author(s):  
G. Carbone ◽  
L. Mangialardi ◽  
G. Mantriota

Today the use of metal V-belt (MVB) on C.V.T. (continuously variable transmission) based systems is the rule in automotive applications. The great advantage of this kind of belt is the capability to resist the moving half-pulley’s high axial thrust necessary to transmit the large torque involved. This paper suggest a theoretical model of belt’s behavior during rapid ratio speed changes with the aim to represent the dynamical response of the system during the transient condition. The paper proposes a relation which correlates some easily measurable macroscopic quantities: axial thrust, torque transmitted and belt’s tensions on the slack and tight side. The metal V-belt consists of wedge-shaped plates that are supported by a flexible band, of which there are two types: the metal V-belt without clearance and the metal V-belt with clearance between plates. Our investigation is carried out for the first type of belt and under the hypothesis that there is a rapid variation of speed ratio. The result, that has been reached, allows to predict the behavior of the system and simplifies the planning of continuously variable transmission with metal V-belt.

2019 ◽  
Vol 9 (10) ◽  
pp. 2074 ◽  
Author(s):  
Hangyang Li ◽  
Yunshan Zhou ◽  
Huanjian Xiong ◽  
Bing Fu ◽  
Zhiliang Huang

The energy management strategy has a great influence on the fuel economy of hybrid electric vehicles, and the equivalent consumption minimization strategy (ECMS) has proved to be a useful tool for the real-time optimal control of Hybrid Electric Vehicles (HEVs). However, the adaptation of the equivalent factor poses a major challenge in order to obtain optimal fuel consumption as well as robustness to varying driving cycles. In this paper, an adaptive-ECMS based on driving pattern recognition (DPR) is established for hybrid electric vehicles with continuously variable transmission. The learning vector quantization (LVQ) neural network model was adopted for the on-line DPR algorithm. The influence of the battery state of charge (SOC) on the optimal equivalent factor was studied under different driving patterns. On this basis, a method of adaptation of the equivalent factor was proposed by considering the type of driving pattern and the battery SOC. Besides that, in order to enhance drivability, penalty terms were introduced to constrain frequent engine on/off events and large variations of the continuously variable transmission (CVT) speed ratio. Simulation results showed that the proposed method efficiently improved the equivalent fuel consumption with charge-sustaining operations and also took into account driving comfort.


2011 ◽  
Vol 291-294 ◽  
pp. 2861-2865 ◽  
Author(s):  
Qiang Jiang ◽  
Hong Yi Liu ◽  
Jian Jun Hao ◽  
Yue Cheng

Electromechanical control CVT (EM-CVT) is a new type of continuously variable transmission, and its ratio quality is an important parameter validated the performance of vehicle. In order to study the dynamical coupling technology between EM-CVT and engine under the running state of vehicle, the special character of two working models is obtained by engine experiment; according to the principle of the EM-CVT, the relation between vehicle speed and ration is theoretically analyzed. Based on the basic theory of PID control, the improved PID control algorithm is proposed for the speed ratio control of the EM-CVT, and experimental verification is made. The experimental results show that there is a significant effect on the system with this algorithm.


Tribologia ◽  
2017 ◽  
pp. 93-100 ◽  
Author(s):  
Wojciech SZCZYPIŃSKI-SALA ◽  
Krzysztof DOBAJ ◽  
Adam KOT

The article describes the results of the research carried out on the evaluation of the influence of friction pairs (rubber belt – belt pulley in belt drive) on the ability to transmit power. In order to determine the characteristics of the belt drive operation, measurements were made on a real belt drive from the drive train of a light two-wheeled vehicle. The measurement was carried out in conditions of changes in the dynamic load. The measurements of the belt slip on the belt pulley within the whole range of the changes of gear ratios and angular speed of the engine were made. During the tests, belts made from various rubber mixtures were compared. The values of the friction coefficients between the surface of belts and the belt pulley were measured. Model analyses of the impact of belt slip on the wheel related to the temperature of Belt drive elements were also made. Generally, one can ascertain that, in belt drive systems, power losses are a combination of speed losses and torque losses. The increase in the efficiency of belt drives is possible by decreasing power losses. It is possible to obtain the high performance of continuously variable transmission belt drives with a V- belt solely with the proper choice of the design parameters, which is possible only after the exact recognition of the operational characteristics unique to this class of belt drive systems.


2014 ◽  
Vol 2014 ◽  
pp. 1-17
Author(s):  
Zhengchao Xie ◽  
Pak Kin Wong ◽  
Yueqiao Chen ◽  
Ka In Wong

Van Doorne’s continuously variable transmission (CVT) is the most popular CVT design for automotive transmission, but it is only applicable to low-power passenger cars because of its low torque capacity. To overcome this limitation of traditional single-belt CVT, a novel dual-belt Van Doorne’s CVT (DBVCVT) system, which is applicable to heavy-duty vehicles, has been previously proposed by the authors. This paper, based on the published analytical model and test rig of DBVCVT, further proposes an intelligent multiobjective fuzzy controller for slip and speed ratio control of DBVCVT. The controller aims to safely control the clamping forces of both the primary and the secondary pulleys in order to improve the transmission efficiency, achieve the accurate speed ratio, and avoid the belt slip under different engine loads and vehicle speeds. The slip, speed ratio, and transmission efficiency dynamics of DBVCVT are firstly analyzed and modeled in this paper. With the aid of a flexible objective function, the analytical model, and fuzzy logic, a Pareto rule base for fuzzy controller is developed for multiobjective DBVCVT control. Experimental results show that the proposed controller for slip and speed ratio regulation of DBVCVT is effective and performs well under different user-defined weights.


Author(s):  
Aditya Dhand ◽  
Keith Pullen

Energy storage devices are an essential part of hybrid and electric vehicles. The most commonly used ones are batteries, ultra capacitors and high speed flywheels. Among these, the flywheel is the only device that keeps the energy stored in the same form as the moving vehicle, i.e. mechanical energy. In order to connect the flywheel with the vehicle drive line, a suitable means is needed which would allow the flywheel to vary its speed continuously, in other words a continuously variable transmission (CVT) is needed. To improve the efficiency and speed ratio range of the variators, a power spilt CVT (PSCVT) can be employed. This paper discusses the kinematics of PSCVT used to connect the flywheel to the driveline. A methodology describing the characteristic equations of speed ratio, power flow and efficiency of the PSCVT for various types including power recirculating and multi regime in both directions of power flow has been presented. An example of a PSCVT for a flywheel energy storage system (FESS) is computed using the derived equations and the results compared.


Author(s):  
PRASAD VINAYAK MARULKAR ◽  
S.G. JOSHI

In this paper, a typical Parallel Disk Continuously Variable Transmission System (PDCVT) is developed in the spirit and approach of Kazerounian and Furu-Szekely. In situations where a speed ratio is required to be changed frequently, continuously variable transmission is one of the desirable solutions. The PDCVT system is one such solution which offers the advantages such as high power to weight ratio and reliability in operation. First of all, the development and manufacturing details of the developed PDCVT system are discussed and experimental and theoretical values of transmission ratios have been determined with different ball diameters and materials. Also, the theoretical and experimental evaluation of transmission torque has been carried out. Experiments have been carried out to determine the system parameters: the stiffness of the spring for preloading mechanism of the system and the area of contact between the balls and rotating disks to determine the coefficient of friction.


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