Design of a novel pressurized chamber to assess in-use durability performance of rolling contact elements using refrigerant lubrication
This source preferred by Mark Hadfield
Authors: Khan, Z.A., Hadfield, M. and Wang, Y.
Start date: 5 September 2004
Due to environmental impact legislation, refrigerants have evolved to include Hydro fluorocarbon’s (HFC) such as R134a and Hydrocarbon’s (HC) such as R600a. Obtaining material wear properties of these refrigerants used in mechanical applications is difficult due to high saturation pressure of the refrigerants. It is important to assess the in-use durability performance of these products from a sustainable development viewpoint. This paper responds to the need for bench testing of rolling contacts using the new generation refrigerants as lubricants. A novel pressurised chamber was designed to achieve a liquid state of the refrigerant as fluid for the rolling contact fatigue experiments. Design parameters such as mass properties, material selection criteria, three-dimensional stress finite element analysis and detailed design of the pressurised chamber are presented. A cooling system used to control the temperature and pressure of the pressurised chamber is described. A high-speed rotary tribometer was used for rolling contact fatigue tests. This paper also presents preliminary experimental study of the influence of the liquid refrigerant lubrication on rolling contact wear of the silicon nitride/steel elements. Preliminary investigations of the lubricated contact of silicon nitride rolling elements using the pressurised chamber reveal that wear rate is affected by the nature and geometry of the induced defect.