Laboratory simulation to select oil seal and surface treatment

Reliability of rotary oil seals depends on many parameters related to seal design and material, shaft material, hardness and surface texture, medium; operating conditions, etc. This presentation will describe the accelerated testing methodology development as well as the results of shaft surface rou ghness and hardness analyses to decrease wear in rotary oil seal lips. Seal s went through 200 h of accelerated testing which not only reproduced opera ting conditions but duplicated field service mode or seal lip and shaft wea r mechanisms during accelerated testing. Dana's new oil seal accelerated te ster has many unique features: (1) reproduction of several extreme operatin g conditions including oil temperature cycling and superposition of recipro cal motion; (2) devices to easily change shaft-to-bare misalignment and sha ft eccentricity, and (3) measurement equipment for torque evaluation and ph oto-optical oil leak detection. The methodology consists of establishing si mple engineering parameters including the number of tested cycles before th e leak, oil seal lip wear path, shaft surface groove depth under oil lip, v arieties of shaft surface roughness, and friction forces between seal Lip a nd shaft surface. An important part of this methodology is detailed metallu rgical and metrological examination of the field and lab test usage of the oil seal lips and shaft surfaces including SEM and EDX analysis. The shaft surface hardness and roughness characteristics, including core roughness de pth, reduced peak height and valley depth, their ratios, and their influenc e on seal lip wear will be presented. (C) 1999 Elsevier Science S.A. All ri ghts reserved.