Hydrostatic transmission – basic principle. - Hydrostatic transmission – circuit
solutions with additional functions. - Power Split drive technology. - Advanced ...
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
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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
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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
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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
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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
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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
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Design and Modeling of Fluid Power Systems, ME 597/ABE 591
SICFP’05, June 1-3, 2005, Linköping
Hydrostatic transmission
“Automotive” control
Engine
© Dr. Monika Ivantysynova
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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
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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
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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: 1 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
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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
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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
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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
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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
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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 = 0
Negative planetary gear, the standing gear ratio i0AC is negative © Dr. Monika Ivantysynova
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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
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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
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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
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Design and Modeling of Fluid Power Systems, ME 597/ABE 591
SICFP’05,toolbox June 1-3, 2005, Linköping PSDD for Simulink
Best Efficiency ?
POLYMOD allows Precise Loss Models
• 21 PIN
VI
nI
MI
nIN
nC
nA
MIN
MC
MA
nII I
II
VII
nOUT
POUT
MOUT
POLYMOD Model
Losses
MII
Losses
MS
Loss Behaviour
MS
Pump & Motor QS = f(Vi, n, Δp)ν = const. MS = f(Vi, n, Δp)ν = const.
© Dr. Monika Ivantysynova
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Design and Modeling of Fluid Power Systems, ME 597/ABE 591
Power Split Drive
SICFP’05, June 1-3, 2005, Linköping
System Example
Development by Claas © Dr. Monika Ivantysynova
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Design and Modeling of Fluid Power Systems, ME 597/ABE 591
