Mechanism analysis and optimisation strategy for the impact of gear oil cleanliness on the service life of wind turbine gearboxes

Abstract
The cleanliness of gear oil has a significant impact on the reliability and service life of wind turbine gearboxes, and often, it is the human factor, unsteady maintenance practices, and weak policy support that are responsible for the oil's compromised condition. Traditional approaches to the reliability of gearboxes have mostly concentrated on either enhancing their mechanical design or using sensors for monitoring, thus neglecting the organizational and behavioral systems that lead to the contamination of oil. The present work suggests a non-technical framework for optimization that emphasizes the change of maintenance culture, well-organized training of the staff, keeping of digital records, and integration of policies rather than the redesign of the mechanical aspect. Through the use of primary qualitative data obtained from interviews, field observations and documents analysis, four major themes emerged—maintenance culture, training and awareness, resource and policy issues, and optimization opportunities. The results indicate that the implementation of condition-based maintenance, digital tracking, and standardized SOPs together can lead to a 25–40% reduction in the number of oil-related gearbox failures and a great enhancement of operational reliability. This study claims the integration of human, organizational, and procedural dimensions into the maintenance optimization process as a unique approach as compared to previous sensor-driven or model-based methods. The framework offered is a sustainable pathway for the further development of oil management performance, the reduction of unplanned downtime, and the prolongation of gearbox service life in wind farms that are fitted with modern technology.