Development of Mechanical Seal against Dust for Lunar Exploration

抄録

The various devices used in lunar activities are exposed to a constant hazard-moon dust. Consequently, appropriate measures must be taken to protect anything with moving parts from a large amount of lunar dust particulates, called regolith, so the development of better seals to protect mechanical components from dust particles is very important. Further, there are considerations such temperature that must be taken into account. This study focuses on face seals such as mechanical seal instead of radial seals because face seals can easily get lower torque than the radial seals since rotational torque is hardly affected by temperature. Mechanical seals were evaluated for use with a main shaft with respect to their effectiveness in protecting motors, gears, and bearings from dust particles. First, a ring-on-ring friction test was carried out to find a suitable material and combination to use as sliding materials. SiC against SiC had good tribological properties in various material combinations. Using a SiC/SiC combination as the sliding materials, mechanical seals were evaluated in a vacuum and under heavy-dust conditions. This paper reports the results of testing seal properties and torque.