Technical Equipment
More than 80 test rigs are available at FZG to conduct experimental investigations. The workshop is equipped with all necessary tools and equipment to produce and maintain the test facilities and measurements. For gear finishing, there is a state-of-the-art gear grinding machine available. Furthermore the institute has an electro/electronic laboratory with the required control and measurement equipment to develop, construct and maintain test rig controls. An overview of these existing facilities is given in the table below. A detailed description of workshop, test facilities and laboratory is documented on the following pages.
Measuring, Materials and Lubricant Laboratory
The documentation, investigations and surveys are carried out in the laboratory. Test specimens pass through surveys before, during and after the experiment. A main part of the investigation of gearwheels is to control shape and position of gear geometry, measured with the gear measuring center. The surface profiles and structures are captured in 2D and 3D roughness measurements. High-tech scales allow the exact specification of weight and therefore the tracing of the weight loss; e.g. during wear tests. The experimental progress as well as all components and test rigs are documented with digital cameras and recorded in a central image database.
In the materials laboratory the standard metallography methods, like sample preparation, grinding, polishing, microstructural characterisation and, for fracture surface analysis scanning electron microscopy are available. Furthermore the laboratory has equipment for surface hardness and hardness profile tests, measurements with X-ray diffractometers (residual stress, retained austenite), and energy dispersive X-ray analysis in the SEM (determination of the composition of inclusions). Material compositions can be controlled with the radio spectrometer (optical emission spectrometry).
In the lubricant laboratory, the viscosity, water content and neutralisation number of lubricants are determined, as well as the chemical composition of base oils and additives.
Workshop
The workshop area of the institute is equipped with all the necessary tools and work equipment to produce and maintain all of the own test rigs and measurement devices. For gear finishing, there is a gear grinding machine ‘Liebherr LGG 280’ (profile and generating grinding process) available.
Electro/Electronic Laboratory
The institute has an electro/electronic laboratory in which required control and measurement equipment for test rig control are developed, constructed and maintained.
Test Rigs at FZG
The test facilities at FZG provide an efficient infrastructure for the investigation of load-carrying capacity, EHL / tribological contact, efficiency, dynamics / NHV, materials / coatings and fatigue strength. Altogether more than 80 test rigs are used.
Back-to-back Gear Test Rig (a = 91.5 mm)
Preloading: mechanical or hydrostatic
Center distance: a = 91.5 mm
Module: mn = 2 … 5 mm
Face width: b = 10 … 40 mm
Load torque: T = 0 ... 800 Nm
Rotational speed: n = 10 ... 3000 1/min
Research issues:
Wear, pitting and micropitting resistance, scuffing, root breakage, flank fracture, fatigue strength, vibration, power loss
Back-to-back Gear Test Rigs (a=91,5 mm)
Arrangement of test rigs in box with oil aggregate as well as test rig control
Back-to-back Gear Test Rig with Speed Reducer
Back-to-back gear test rig with speed reducer to adjust the speed and torque
Back-to-back Gear Test Rig (a > 91.5 mm)
Center distance: a = 112.5 mm, 140 mm, 200 mm
Module: mn = 2 … 12 mm
Face width: b = 10 … 80 mm
Load torque: T = 0 … 4000 Nm
Rotational speed: n = 100 … 3000 1/min
Dynamic Test Rig (a = 140 mm)
Research issues:
Dynamic forces in spur and helical gears, torsional acceleration in the wheel body, structure borne noise measurement on the transmission housing, transmission error under load
Load Spectra Test Rig
Application of torque with hydrostatic load device for the investigation of operational load-carrying capacity
FZG Test Rig for Small Gears
Center distance: a = 7.5 … 58.8 mm
Module: mn = 0.3 … 1.0 mm
Face width: b = 4.5 … 15 mm
Load torque: T = 0 … 150 Nm
Rotational speed: n = 100 …10000 1/min (stageless)
FZG Internal Gear Test Rig
Center distance: a = -59 mm
Module: mn = 4.5 mm
Face width: b = 14 mm
Load torque: THr = 0 … 6000 Nm
Rotational speed: v = 0.05 …10 m/s
FZG Three-Shaft Test Rig
Center distance: a = 65 ... 85 mm
Module: mn = 1.5 … 4.5 mm
Face width: b = 10 … 30 mm
Load torque: T = 0 … 700 Nm
Rotational speed: n = 100 … 3000 1/min
FZG Efficiency Test Rig
Center distance: a = 91.5 mm
Max. force levels: LSmax = 10, T1max = 372.6 Nm
Speed: v = 0.5 … 20 m/s
Oil temperature: ϑoil = 30 … 120 °C
Research issues:
Dissipation, efficiency, heat balance and frictional behaviour of lubrication and lubricant, tooth geometry and flank surface, no-load behaviour
Hydraulic Pulsator
Frequency range: ca.10 … 60 Hz
Max. dyn. force: ± 60 ... ± 100 kN
Max. sample length: 20 … 100 mm
Research issues:
Static and dynamic strength characteristics by classifying and load spectra tests; e.g. root strength of spur gears
Electromagnetic High-Frequency Pulsator
Frequency range: ca.30 … 150 Hz
Max. dyn. force: ± 50 ... ± 250 kN
Max. sample length: 200 … 1000 mm
Research issues:
Static and dynamic strength characteristics by classifying and load spectra tests; e.g. root strength of spur gears
Mechanical Resonance Pulsator
Frequency: ca.35 Hz
Max. dyn. force: ± 200 kN
Max. sample length: 1000 mm
Research issues:
Dynamic strength characteristics through single-step tests, e.g. root strength of large spur gears and gear racks
FZG Bevel and Hypoid Gear Test Rig (mechanically or hydrostatically loaded)
Axial offset: a = -15, 0, 15, 25, 31.75, 44 mm
Max. testing power: Pmax = 300 kW
Outer reference diameter of the gear: de2 = 170 mm
Speed range: n1 = 100 …4800 1/min
Research issues:
Pitting and micropitting, scuffing, tooth flank fracture and tooth root breakage, basic investigations
FZG Worm Gear Test Rig (electrically loaded)
Center distance: a = 40, 65, 100, 160 mm
Input rotational speed: n1max = 3000 1/min
Output torque: T2max = 400 Nm
Research issues:
Wear behaviour and pitting resistance, scuffing, lubricant / material investigations, efficiency, rotational speed / load spectra
FZG Worm Gear Test Rig (hydrostatically loaded)
Center distance: a = 65mm, 100mm, 160 mm
Input rotational speed: n1max = 1500 1/min
Output torque: T2max = 1800 Nm
Research issues: Wear behaviour and pitting resistance, scuffing, lubricant / material investigation, efficiency, rotational speed / load spectra
FZG Worm Gear Test Rig (hydrostatically loaded)
Center distance: a = 315 mm
Input rotational speed: n1max = 1500 1/min
Output torque: T2max = 21000 Nm
Research issues:
Wear behaviour and pitting resistance, scuffing, lubricant / material investigation, efficiency, rotational speed / load spectra
Standard-Synchronizer-Test Rig (ZF / FZG SSP-180)
Max. friction torque: TR = 400 Nm
Max. axial force: Fa = 4000 N
Inertia:
- coupling JK = 0.01 … 0.4 kgm²
- vehicle J0 = 1.75 kgm²
Difference in rotation: Δn = 3000 (5000) 1/min
Research issues:
Friction, wear and fatigue life behaviour of synchronizers, shift operations, load spectra
FZG Drag Torque Test Rig
Resolution of measuring shaft: 0.02 Nm
Rotational speed shaft K: nK = -6000 … 6000 1/min
Rotational speed shaft F: nF = -3000 … 3000 1/min
Research issues:
The drag torque behaviour of synchronizations under variation of operation conditions (e.g. oil temperature ϑoil = -20 … 120 °C).
Multidisc Clutches Test Rig LK-1
Max. friction torque: Tmax = 1500 Nm
Max. rot. speed: ns,max = 5000 1/min
Flywheel inertia: Js = 0.2 … 4 kgm²
Max. outer diameter of frict. surf.: dA,max = 400 mm
Shudder Test Rig LK-2
Max. friction torque: Tmax = 1500 Nm
Max. rot. speed: ns,max = 3000 1/min
Flywheel inertia: Js = 0.2 … 1.6 kgm²
Max. outer diameter of frict. surf.: dA,max = 250 mm
Research issues:
Friction, wear and shudder behaviour, breakaway and slip behaviour, heat management, braking and continuous slipping operation
Multidisc Clutches Test Rig LK-3
Max. friction torque: Tmax = 750 Nm
Max. rot. speed of gyr. mass: ns,max = 5500 1/min
Flywheel inertia: Js = 5 kgm²
Max. outer diameter of frict. surf.: dA,max = 250 mm
Research issues:
Load transfer behaviour, fatigue life, wear, oil aging, heat management, dyn. oil flow capacity
Drag Torque Test Rig - Multidisc Clutches LK-4
Rotational speed: n1,2 = ± 11000 1/min
Max. drag torque : TR,max = 50 Nm
Max. outer diameter of frict. surf.: dA,max = 300 mm
Multidisc Clutches Test Rig KLP-260
Max. friction torque: TR = 2000 Nm
Max. axial torce: Fa = 20 N
Inertia: J1= 1.0; J2 = 0.1 … 0.75 kgm²
Difference in rotational speed: Δn = 7000 1/min
Research issues:
Friction, wear and fatigue life behaviour of multidisc clutches and synchronizer, drag torque, heat management, braking operation, load spectra
Rolling Element Bearings Power Loss Test Rig
Max. engine power: Pmax = 15 kW
Force per bearing:
- radial Fmax,rad = 125 kN
- axial Fmax,ax = 80 kN
Bearing speed: nbearing < 5000 1/min
Research issues: The total and bearing power losses, bearing load.
Type of bearing: Adjusted bearing mounting: angular contact ball, tapered roller bearing Radial bearing: deep groove ball/cylind. roller bearing
Rolling Element Bearings Lubricant Test Rig FE-8
Rotational speed: n = 7.5 … 3000 1/min
Axial load: Fa = 100 … 100000 N
Temperature range: ϑbearing = 20 … 200 °C
Friction conditions: boundary and mixed friction
Research issues:
Friction, temperature and wear behaviour of lubricating oils and greases under lubricant and bearing specific influence
Twin-Disc Test Rigs
Center distance: a = 80 mm
Disc diameter: d = 80 mm
Max. normal force: FN,max = 16 kN
Speed: v1/2 = 0 … ± 25 m/s
Research issues:
EHL basic research (pressure, temperature, lubricant film thickness profile), friction coefficient of lubricants, contact strength analysis
EHD Tribometer
Contact Load: FN = 5 ... 125 N
Entrainment velocity: vm = 0,001 ... 2 m/s
Slide-to-roll ratio: SRR = -199% ... 199%
Oil temperature: ϑOil = ambient to 150 °C
Research Topics:
Tribology basic research
Determination of local lubricant film thickness
Basis for validation of TEHL simulations
Three-Disc Test Rig
Center distance: a = 100 mm
Input rotational speed: n1max = 1500 1/min
Oil injection temperature : ϑ = 25 … 100 °C