Study on Improving the Reliability of a Domestic Refrigerator Compressor Subjected to Repetitive Loading

Parametric accelerated life testing (ALT) was used to assess the lifetime of a newly designed
compressor of a commercial refrigerator subjected to repetitive pressure loading. It consists of (1)
parametric ALT plan based on product BX lifetime that will be X percent of the accumulated failure, (2)
load analysis for ALT, (3) a tailored series of parametric ALTs with the design modifications, and (4)
evaluation of whether the design(s) of product achieves the target BX lifetime. Based on the basic
refrigeration cycle, a generalized life-stress failure model and new sample size equation with a new
load concept was derived. Using the sample size equation with the acceleration factor also enabled
the parametric accelerated life testing to quickly evaluate the expected lifetime. The design of this
testing should help an engineer uncover the design parameters affecting reliability during the design
process of the compressor system. Consequently, it should help companies improve product lifetime
and avoid recalls due to the product failures in the field. A newly designed compressor in a
commercial refrigerator was used as a test case. Finally, engineers can use parametric ALT to identify
and correct design problems of a mechanical system.