Design and Modeling of Fluid Power Systems ME 597/ABE 591 - Lecture 15 Dr Monika Ivantysynova MAHA Professor Fluid Power Systems MAHA Fluid Power Research Center Purdue University SICFP’05, June 1-3, 2005, Linköping Hydrostatic transmissions - Hydrostatic transmission – basic principle - Hydrostatic transmission – circuit solutions with additional functions - Advanced transmission concepts - Power Split drive technology © Dr Monika Ivantysynova 2 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Hydrostatic transmission Basic Circuit Design © Dr Monika Ivantysynova Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Hydrostatic transmission Two variable units –controlled in sequence M… torque P… power © Dr Monika Ivantysynova V… displacement Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Hydrostatic transmission Two variable units – simultaneously controlled © Dr Monika Ivantysynova Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Hydrostatic transmission Pump control – manually, with mechanical feedback © Dr Monika Ivantysynova Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Hydrostatic transmission Pressure limiter Engine © Dr Monika Ivantysynova Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linkưping Hydrostatic transmission “Automotive” control Engine © Dr Monika Ivantysynova Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Hydrostatic transmission With electrohydraulic controlled displacement units © Dr Monika Ivantysynova Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Example Wheel loader Lifting/Tilting Steering 17.4:1 1:1 or 1.4:1 17.4:1 © Dr Monika Ivantysynova 10 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Wheel loader Transmission Design Example Design the hydrostatic transmission for a given wheel loader and calculate the traction force- speed characteristic for the entire speed range The following parameters and requirements are given: Engine speed: 2200 rpm Engine power: 90 kW Vehicle mass: 10 t Bucket volume: m3 Density soil: 2kg/dm3 Dynamic roll radius: 0.617 m Coefficient of rolling resistance (soil): 0.08 Coefficient of rolling resistance (asphalt): 0.015 Max vehicle speed (on road): 40 km/h Max traction force: 25 kN © Dr Monika Ivantysynova 11 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 © Dr Monika Ivantysynova 12 Mass variable motor Max Speed @ ß=7° Displacement Volume ß=7° Mass fixed displ motor Torque @ 350 bar Fixed displ motor Mass variable pump Displacement charge pump Power @ 100 bar, 1000 rpm Theoretical flow rate @1000 rpm Max Pressure Max Pressure (contin.) Max Speed Max Displacement Volume SICFP’05, June 1-3, 2005, Linköping Axial piston machines Selected pump and motor sizes Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Trends & New Requirements • High traction force & high max speed • Continuously variable transmission (CVT) • Reduction of fuel consumption • Cost effective 25 mph and more FZ 100,0 kN and more ve © Dr Monika Ivantysynova 13 vmax v Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Transmissions - today Power Shift Gearbox with hydro dynamic torque converter • state of the art solution • complex, multi-stage gear system • high number of clutches • low starting efficiency K1 • interrupted power flow K2 C/E © Dr Monika Ivantysynova 14 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, JuneMotor 1-3, 2005, Concept Linköping Multiple Zero-adjustable Hydraulic Motor F, β βVM βPump I II III © Dr Monika Ivantysynova unlock v 15 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Power Split Drive Basic structure Ring wheel Satellite carrier Sun wheel additive mode © Dr Monika Ivantysynova recirculating mode 16 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 Planetary Gear SICFP’05, June 1-3, 2005, Linköping Three wheel planetary gear train Willis equation: When satellite carrier B is block nB = Negative planetary gear, the standing gear ratio i0AC is negative © Dr Monika Ivantysynova 17 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3, 2005, Linköping Planetary Gear negative standing gear ratio i0AC Speed of individual wheels: Directions of rotation of sun wheel A and ring wheel C are different, when the satellite carrier B is blocked! © Dr Monika Ivantysynova 18 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 Power Split Drive SICFP’05, June 1-3, 2005, Linköping Output coupled System Fendt, Germany, developed a transmission system for agricultural tractors, which is in series production since 1996 © Dr Monika Ivantysynova 19 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 Power Split Drive SICFP’05, June 1-3, 2005, Linköping Input coupled System Sundstrand Corporation - Responder transmission New development by John Deere © Dr Monika Ivantysynova 20 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 ... Ivantysynova Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3 , 2005, Linköping Hydrostatic transmission Pressure limiter Engine © Dr Monika Ivantysynova Design and Modeling of. .. Reduction of fuel consumption • Cost effective 25 mph and more FZ 100,0 kN and more ve © Dr Monika Ivantysynova 13 vmax v Design and Modeling of Fluid Power Systems, ME 597/ABE 591 SICFP’05, June 1-3 ,... Monika Ivantysynova 19 Design and Modeling of Fluid Power Systems, ME 597/ABE 591 Power Split Drive SICFP’05, June 1-3 , 2005, Linköping Input coupled System Sundstrand Corporation - Responder transmission