## 5 Conclusions  
This work focuses on the experimental evaluation of the impact of lubricant filtration and tribological parameters on the reliability, longevity, and functional characteristics of gear mechanisms used in robotics. The results were evaluated using the ISO 4406 standard, which is used to determine the contamination class of lubricating fluids. Based on knowledge from the field of gear reducer and robotic system design, a mobile filtration system was proposed and implemented to test the impact of filtration on the operational characteristics of gearboxes, including the introduction of online monitoring of tribological parameters. As part of the research, a test station was developed, consisting of load benches simulating cyclic loading of gear units. Thanks to precisely defined measurement parameters, it was possible to analyze and quantify the effect of filtration on the kinematic and performance characteristics of gear mechanisms, creating space for maintenance optimization and the design of effective technical solutions in industrial robotics. The novelty of the presented research lies in the combination of a custom-designed mobile filtration unit with an online diagnostic system for real-time monitoring of lubricant condition and gear performance under dynamic load. Unlike conventional approaches, which rely on offline oil sampling and visual inspection, the method enables early detection of critical wear-related trends and real-time response to contamination spikes. After the implementation of the filtration system and the removal of contaminant particles from the lubricant, a decrease in the required torque values was observed. In contrast, the unfiltered gear module showed a continuous increase in torque due to progressive wear and contamination. Comparative analysis of lubricant samples revealed that after 10 h of operation without filtration, the contamination level was significantly higher than after 32 weeks of operation with 32 h of cumulative filtration. For the smallest contaminant particles, the concentration was reduced to approximately 7% of its original value. Significant sliding and micro-slip wear were also detected, particularly affecting the rolling elements, where improper rolling led to local sliding behavior. This condition contributed to higher torque values and the occurrence of wear particles typical for fatigue and abrasive wear. The filtration system succeeded in reducing the occurrence of these particles by approximately 50%, indicating a partial but meaningful mitigation of the underlying wear mechanisms. The benefits can be summarized through the following points:  
* The research highlights a sharp rise in contamination during initial operation hours, stressing the need for timely intervention to avoid reduced gear module reliability. * The study confirms that efficient filtration reduces failures, extends gearbox life, and lowers maintenance costs. * A specialized test station was developed for assessing lubrication strategies, and online monitoring of tribological parameters was introduced to support predictive maintenance. * The approach promotes environmental responsibility by minimizing waste and offers strong practical value in industries demanding high robotic system reliability. * The study emphasizes the importance of addressing tribological components from the design phase to operation, supporting system reliability in robotics. * The conclusions are supported by experimental data reflecting the reduction of contaminant particle levels and torque stabilization, providing a clear correlation between lubrication cleanliness and system performance. * Although the study is focused on robotic gear mechanisms, the methodology and results offer a transferable framework for condition monitoring and maintenance optimization in other high-precision, cyclically loaded gear systems. * An advantage of the proposed method is its modularity and applicability in real-time conditions without interrupting system operation.