Experimental Wear Analysis on Mechanical Seals for Concrete Mixers

The paper presents an experimental wear analysis of amechanical face seal for twin-shaft concrete mixers. The studied mechanical seals are lubricated through a timed pump which delivers grease progressively and distributes the required amount of lubricant to each seal evenly. Seals aim at preventing the leakage of the dough from the tank of the concrete mixer through the gaps between the fixed and rotating parts. To prevent the dough from spilling out, the flow is contrasted by adding lubricating grease. The seals, after a certain period of operation, exhibit significant wear progress due to an interlayer of concrete/inert material. The experimental wear analysis is carried out with the aid of 3D scanners and from the observation of the results, three different phases are defined during the material removal, considering different wear behaviors. Results are also compared to wear volumes from gravimetric tests. Therefore, this paper lays the groundwork for a future model of the wear behaviour of mechanical face seals in twin-shaft concrete mixers and for proposing solutions to limit and control the wear phenomena.