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.

 

Overview Test Rigs at FZG

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

 

 Research issues:

Wear, pitting and micropitting resistance

 

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

 

Research issues:

Investigation of cylindrical gears with variable center distance (e.g. automotive)

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

 

Research issues:

Friction and wear behaviour, heat management

 

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

 

Research issues:

Drag losses, groove variants, oil and oil flow

 

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

Research issues:

Friction coefficients, influence of speed ratios/ temperature/material and lubricant on local coefficient of friction

 

Universal Test Rig for Drive Systems (UPA)

 

Dimension of the mounting plate: 2.6 m x 5.9 m

Power of the load machine: 27 … 160 kW

Ratio of the adaption transmission: 5 … 10

Equipment: Exhaust suction system, connection to

process cooling circuit, rapid control prototyping