TE 74 TWO ROLLER MACHINE

 





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    General Description

    The TE 74 Two Roller Machine is for the study of traction, wear and rolling contact fatigue under conditions of heavily loaded, lubricated, pure rolling and rolling and sliding. The machine incorporates two motors, one to provide the input power and one to absorb the transmitted power.

    To achieve the necessary high loads with small diameter rollers, hence high contact pressures, the test rollers our mounted on shafts with bearings on either side, in the “fully supported” configuration. As a consequence, spindle bearings are exposed to, and must run in, the test lubricant.

    To achieve satisfactory performance in line contact, the mounting/loading arrangement has adjustable alignment, with the upper specimen shaft carried on a pivoted arm and with a spherical bearing incorporated in the pivot axle. Axial alignment is achieved by indexing the pivot axle. Loading is achieved by means of a servo controlled pneumatic bellows actuator with force transducer feedback.

    The lower specimen shaft is carried in fixed bearings. The drive to the lower roller incorporates an in-line torque transducer for measuring the input torque to the system. It should be noted that the traction measurement is thus subject to parasitic losses associated with the roller spindle bearings. These losses are small but may be quantified by running the unit under conditions of zero slip at different speeds and temperatures.

    A vibration sensor is provided for detecting surface failure. The upper roller housing is electrically insulated and slip rings are provided on the roller shafts for electrical contact resistance measurement.

    A lubricant service module is fitted as standard incorporating a sump tank with immersion heater, delivery pump, scavenge pump and oil to water heat exchangers for cooling.

    The motors are a.c. and powered by conventional vector drives allowing precise control of speed. Power is re-circulated electrically via a common d.c. link between the drives, upstream of the frequency inverter stages. Total power requirement is thus limited to the system losses. For control purposes, one drive is designated as master with the second drive deriving its speed set point, adjusted for the required slip ratio, from the master drive.

    Design Variants

    Two versions of the machine are available. The TE 74S (standard capacity) incorporates two 5.5 kW motors, a shaft centre distance of 40 mm and 12 kN loading system, whereas the TE 74H (high capacity) has two 30 kW motors, a shaft centre distance of 70 mm and 30 kN loading system.

    Drive Configuration:

    The lower roller spindle is connected to an in-line torque transducer via a cardan shaft; the transducer is connected to a lay shaft by a coupling and the lay shaft connected to the motor by pulley and timing belt. The upper roller spindle is connected to a lay shaft by a cardan shaft and the lay shaft connected to its motor by pulley and belt drive.

     

    Control and Data Acquisition

    The TE 74 has PC based sequence programmable control and data acquisition. This is provided by an integrated Serial Link Interface Module and COMPEND 2000 software running on a host PC, operating under Windows. Data is stored to hard disc in standard spread sheet compatible file formats (.csv or .tsv).

    Tests are defined by a sequence of steps, each step containing set-point, data recording rates and alarm level information. Set-points may be adjusted by step change or ramp. The test sequence is followed unless interrupted by the operator or an alarm. Set-points may also be adjusted manually using on screen toggles.

    Operating Envelope – TE 74S

    Characteristic showing motor torque-speed characteristic (available torque) compared with roller generated torque, assuming traction coefficient of 0.1, with corresponding reduction in applied load. Note that the full load can be applied at full speed in pure rolling or under conditions where the traction coefficient is less than 0.07.

    Assuming 40 mm diameter rollers and traction coefficient of 0.1, the maximum permissible load at maximum speed is 8.7 kN.

    Note that as the minimum specimen diameter is 15 mm, a diameter of greater than this is required for a crowned roller sample machined on a 15 mm shaft. The practical minimum diameter for a crowned roller is thus 20 mm.

    Operating Envelope – TE 74H

    Characteristic showing motor torque-speed characteristic (available torque) compared with roller generated torque, assuming traction coefficient of 0.1, with corresponding reduction in applied load. Note that the full load can be applied at full speed in pure rolling or under conditions where the traction coefficient is less than 0.08.

    Assuming 70 mm diameter rollers and traction coefficient of 0.1, the maximum permissible load at maximum speed is 27.3 kN.

    Note that as the minimum specimen diameter is 30 mm, a diameter of greater than this is required for a crowned roller sample machined on a 30 mm shaft. The practical minimum diameter for a crowned roller is thus 40 mm.

     



  • Technical Specifications

    Technical Specifications – TE 74S

    Type: Circulating power
    Fully supported roller
    Spindles adjacent
    Fixed shaft centre distance
    Contact: Line or point contact
    Test Conditions: Pure Rolling
    Sliding/Rolling
    Environment: Lubricated
    Standard Roller Diameters: 40 mm on 40 mm
    Maximum Roller Difference: 65 mm on 15 mm
    Maximum Roller Thickness: 12 mm
    Shaft Centre Distance: 40 mm
    Maximum Load: 12 kN
    Roller Temperature: Ambient to 150°C
    Motor Power: 5.5 kW
    Motor Base Speed: 1500 rpm
    Motor Maximum Speed: 3000 rpm
    Drive Ratio: 1:1
    Maximum Roller Speed: 3000 rpm
    Maximum Torque at 1500 rpm: 35 Nm
    Maximum Torque at 3000 rpm: 17.5 Nm
    Maximum Surface Speed (40 mm Roller): 6.28 ms-1
    Drive Ratio: 2:1
    Maximum Roller Speed: 6000 rpm
    Maximum Torque at 3000 rpm: 17.5 Nm
    Maximum Torque at 6000 rpm: 8.75 Nm
    Maximum Surface Speed (40 mm Roller): 12.56 ms-1
    Drive Ratio: 1:2
    Maximum Roller Speed: 1500 rpm
    Maximum Torque at 750 rpm: 70 Nm
    Maximum Torque at 1500 rpm: 35 Nm
    Maximum Surface Speed (40 mm Roller): 3.14 ms-1
    Controlled Parameters Motor speed
    Motor speed difference
    Applied load
    Test fluid temperature
    Test duration
    Measured Parameters Motor speed
    Motor speed difference
    Applied load
    Transmitted torque
    Lubricant inlet temperature
    Test bath outlet temperature
    Vibration sensor output
    Electrical contact resistance
    Services
    Electricity: 380/415V, three phase plus neutral, 50/60 Hz, 15 kW
    Clean, dry air: 4 cfm at 8 bar (120 psi)
    Mains water and drain: 10 l/min (typical)

    Technical Specifications – TE 74H

    Type: Circulating power
    Fully supported roller
    Spindles adjacent
    Fixed shaft centre distance
    Contact: Line or point contact
    Test Conditions: Pure Rolling
    Sliding/Rolling
    Environment: Lubricated
    Standard Roller Diameters: 70 mm on 70 mm
    Maximum Roller Difference: 110 mm on 30 mm
    Maximum Roller Thickness: 12 mm
    Shaft Centre Distance: 70 mm
    Maximum Load: 30 kN
    Roller Temperature: Ambient to 150°C
    Motor Power: 30 kW
    Motor Base Speed: 1500 rpm
    Motor Maximum Speed: 3000 rpm
    Drive Ratio: 1:1
    Maximum Roller Speed: 3000 rpm
    Maximum Torque at 1500 rpm: 190 Nm
    Maximum Torque at 3000 rpm: 95 Nm
    Maximum Surface Speed (70 mm Roller): 11 ms-1
    Drive Ratio: 2:1
    Maximum Roller Speed: 6000 rpm
    Maximum Torque at 3000 rpm: 95 Nm
    Maximum Torque at 6000 rpm: 47.5 Nm
    Maximum Surface Speed (70 mm Roller): 22 ms-1
    Controlled Parameters Motor speed
    Motor speed difference
    Applied load
    Test fluid temperature
    Test duration
    Measured Parameters Motor speed
    Motor speed difference
    Applied load
    Transmitted torque
    Lubricant inlet temperature
    Test bath outlet temperature
    Vibration sensor output
    Electrical contact resistance
    Services
    Electricity: 380/415V, three phase plus neutral, 50/60 Hz, 75 kW
    Clean, dry air: 4 cfm at 8 bar (120 psi)
    Mains water and drain: 10 l/min (typical)



  • Publications

     

     

    Paper # 400 Determination of Gear Tooth Friction by Disc Machine
    Johnson K L, Spence D I,
    Tribology International Volume 24 No 5 October 1991
    Paper # 722 Contact Fatigue Tests and Contact Fatigue Life Analysis
    Hong Lin, Gregory A Fett, Robert R Binoniemi, Mick Deis
    SAE Paper – 2005-01-0795 – 04/11/2005
    Paper # 891 White structure flaking (WSF) in wind turbine gearbox bearings: effects of ‘butterflies’ and white etching cracks (WECs)
    MH Evans
    Materials Science and Technology, Volume 28, Number 1, January 2012 , pp. 3-22(20)
    Paper # 898 Serial Sectioning, FIB and TEM Investigations of Butterfly and White Etching Crack (WEC) Formation
    M Evans, L Wang and R Wood
    World Tribology Congress 2013 Torino, Italy, September 8 – 13, 2013
    Paper # 928 Rolling Contact Fatigue: Experimental Study of the Influence of Sliding, Load, and Material Properties on the Resistance to Micropitting of Steel Discs
    P Rabaso, T Gauthier, M Diaby, F Ville
    Tribology Transactions Volume 56, Issue 2, 2013
    Paper # 929 A FIB/TEM study of butterfly crack formation and white etching area (WEA) microstructural changes under rolling contact fatigue in 100Cr6 bearing steel
    MH Evans, JC Walker, C Ma, L Wang, RJK Wood
    Materials Science and Engineering: A Volume 570, 15 May 2013, Pages 127–134
    Paper # 930 White Etching Crack (WEC) Investigation by Serial Sectioning, Focused Ion Beam and 3-D Crack Modelling
    MH Evans, L Wang, H Jones, RJK Wood
    Tribology International Volume 65, September 2013, Pages 146–160
    Paper # 931 Effect of hydrogen on butterfly and white etching crack (WEC) formation under rolling contact fatigue (RCF)
    MH Evans, AD Richardson, L Wang, RJK Wood
    Wear Volume 306, Issues 1–2, 30 August 2013, Pages 226–241

     

  • User List

    Launched 2001

    University of Leoben Austria
    PSA France
    SNECMA France
    IST Fraunhoffer Braunschweig Germany
    IIT Patna India
    KSSI Korea
    Busan National University Korea
    Southampton University UK
    DANA Corporation USA
    Timken USA


  • Download the Machine Leaflet