Current research projects

Image In-situ investigation concerning the swelling behaviour of polymer materials under elevated pressures and temperatures
Image Behavior of multiphase cryogenic fluids
Image Investigation according to DIN EN ISO 14903
Image Performance tests of refrigerant compressors
Image Influenced melting point of water by magnetic field
Image Low temperature – test facilities
Image Software for technical building equipment
Image Calibration of Low Temperature Sensors
Image Innovative Parahydrogen Generator Based on Magnets
Image Investigation of material-dependent parameters
Image Certification of efficient air conditioning and ventilation systems through the new "indoor air quality seal" for non-residential buildings
Image Computational fluid dynamics CFD
Image Energy efficiency consulting - cogeneration systems
Image Thermal engines
Image State of system and failure analyses
Image Multifunctional electronic modules for cryogenic applications

You are here:   /  Home


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

 


Your Request

Further Projects

Image

Low noise and non metallic liquid-helium cryostat

Low-noise Magnetic Field Cryostat for SQUID-Applications

Image

Cryostats, Non-Metallic and Metallic

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

Image

Calibration of Low Temperature Sensors

According to the comparative measurement method

Image

High Capacity Pulse Tube Cooler

for Cryogenic High-Power Applications