In this work the remote actuation hydraulic circuit of a mid-size agricultural tractor has been studied and modelled in order to identify and evaluate the most relevant energy dissipation contributions. The standard architecture of the remote actuation hydraulic circuit is a hydraulic load sensing system (HLSS) with proportional valves which manage the flow; this system proves to be reliable, robust and characterized by relatively low energy dissipations. However, different critical features characterize it, as the high energy dissipation introduced by the meter out section when the proportional valve is partially open to meet the flow demand of the user, the inability to manage overrunning loads, the pressure saturation of the system when an actuator has reached its end stop and the other actuators are forced to work at the maximum pressure of the system, activating the local pressure compensators. In this work, in order to identify a circuit architecture characterized by lower energy consumption, an independent metering configuration realized with two independent proportional valves, has been applied introducing a control algorithm to adjust the opening and closing of the proportional valves on the basis of the flow demand of the user. The flow demand is satisfied adjusting the proportional valve at the inlet of the actuator, while the proportional valve at the outlet is completely open in case of resistant load. When overrunning loads occur during the operating of the system, a control strategy operates in order to adjust also the proportional valve at the outlet of the actuator in a way that a certain back pressure is set to control the actuator and avoid cavitation. The energy consumptions of the HLSS and of the Independent Metering System have been compared on the basis of two different duty cycles involving resistant and overrunning loads and the new system proved to be less energy consuming. Moreover, using a front loader on a tractor, a duty cycle was experimentally replicated according to which the tractor charges/discharges a load. The pressures, from which the loads on the actuators were derived, and flow demands measured during the cycle were used as input variables on the two virtual models realized and finally the energy consumption at the pump in the two cases was compared obtaining a percentage energy saving of 17% for the new system.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Energy consumption of the hydraulic circuit of a mid-size power tractor


    Additional title:

    Energieverbrauch der Hydroschaltung eines Mittelklasse-Ackerschleppers


    Contributors:


    Publication date :

    2010


    Size :

    14 Seiten, 9 Bilder, 10 Quellen



    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Agricultural tractor hydraulic power use

    Burk, P. | Tema Archive | 1981


    Agricultural Tractor Hydraulic Power Use

    Burk, Ron | SAE Technical Papers | 1981


    Hydraulic steering tractor

    WANG XINGHONG / PAN DEYONG | European Patent Office | 2015

    Free access

    Hydraulic power output system of tractor

    QIN HUANNAN / ZHANG XIN / JIANG FULAI et al. | European Patent Office | 2023

    Free access

    Tractor hitches and hydraulic systems -- Tractor designer's viewpoint

    Brock, H.L. | Engineering Index Backfile | 1953