Triboelectric nanogenerators (TENGs) have emerged as a transformative technology for self-powered sensing and harvesting ubiquitous ambient mechanical energy. However, a critical bottleneck hindering their long-term reliability is the inevitable material wear and performance degradation caused by sustained friction between contacting layers. This work presents a slotted rotor-based TENG (SR-TENG) that fundamentally addresses this wear challenge through an intermittent contact mechanism. The core innovation lies in a unique structural comprising a rotating shaft with precisely machined axial slots and a rotor disk equipped with a spring-loaded pin. As the shaft rotates, the pin engages with the helical slots, converting the uniform rotary motion into a controlled, periodic vertical reciprocating motion of the entire rotor assembly. This mechanical transformation shifts the operational mode from continuous sliding contact to periodic contact-separation cycles between the rotor-mounted electrode and the stationary bottom triboelectric layer, thereby drastically minimizing direct friction time. Systematic experimental characterization demonstrates the efficacy of this design. Quantitative analysis confirms a 90% reduction in contact friction duration per cycle for this design compared with those for the standard rotary TENGs. The SR-TENG consistently delivers a stable open-circuit voltage of 40 V at 200 r/min. More critically, the device exhibits outstanding durability. After undergoing a rigorous accelerated test consisting of 288000 continuous cycles, the SR-TENG retains over 95% of its initial electrical output. Microscopic inspection via scanning electron microscopy reveals that the delicate microstructures on the triboelectric layer surface remain intact, with no observable abrasion, providing the direct physical evidence of the wear-mitigation effect. Beyond energy harvesting, the SR-TENG functions as a self-powered rotational speed sensor. Its output signal frequency shows an excellent linear relationship with rotational speed, and the device features a rapid dynamic response time of less than 10 ms, enabling precise real-time monitoring. In conclusion, this study proposes a highly effective and mechanically elegant structural strategy to solve the wear problem in rotary TENGs. The SR-TENG design not only ensures exceptional long-term operational stability and performance retention but also demonstrates versatile functionality as a sensor. This work provides a viable pathway for developing durable self-powered systems, with significant application potential in industrial equipment condition monitoring, distributed IoT (Internet of Things) sensor networks, and smart infrastructure.