Current research projects

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Image Tribological investigations of oil-refrigerant-material-systems
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Image Refrigerants, lubricants and mixtures
Image Modular storage system for solar cooling
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Image Innovative Manufacturing Technologies for Cryosorption Systems
Image Multifunctional electronic modules for cryogenic applications
Image Development of a Cryogenic Magnetic Air Separation Unit
Image Influenced melting point of water by magnetic field
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Tribological investigations of oil-refrigerant-material-systems

Dr.-Ing. Margrit Junk

+49-351-4081-5419

Modified Almen-Wieland wear testing machine

The modified Almen-Wieland wear testing machine is used for the determination of the tribological properties of oil-refrigerant-bearing-systems under mixed friction conditions. The interaction of lubricants, additives, refrigerants and materials is tested. On the basis of these investigations refrigeration oils and materials could be preselected, but the tests can not substitute field test with refrigeration machines.

Principle

Two half bearings are pressed hydraulically against a test pin rotating horizontally in the lubricant.

The extreme pressure failure, i. e. the load bearing capacity of oil, is determined by increasing continuously or stepwise the test load until seizure of pin and bearing occurs and the pin breaks. The coefficient of friction and the wear are determined with constant (low) load applied during a prescribed test time.

Specialties

  • Hermetic test cell, which allows testing with refrigerant pressures up to 10 bar.
  • Thermostated test cell for a defined lubricant temperature.
  • Continuous record of fest force, turning moment, pressure of refrigerant, temperature and wear.
  • Use of both Almen-Wieland and half bearings with Falex geometry (dimensions of the V-block than the original Falex bearings according to ASTM D 3233).
  • Adaption of the tribological system by choosing materials of test pins and half bearings.

Our services

  • Evaluation of lubricant-refrigerant-material-systems by load bearing capacity of lubricant (extreme pressure failure load), coefficient of friction, wear, changes of lubricant
  • Evaluation of tribological systems after changing lubricants, refrigerants or bearing materials in order to minimize expensive field tests
  • Failure analysis

 


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Further Projects

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Cryostats, Non-Metallic and Metallic

position indenpendent, highest endurance, tiltable for liquid helium and liquid nitrogen

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Calibration of Low Temperature Sensors

According to the comparative measurement method

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High Capacity Pulse Tube Cooler

for Cryogenic High-Power Applications

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Thermal engines

Power Generation from Waste Heat