The effect of pressure and temperature is not a problem. Lubrication of the 'skates' is. Mazda partly solved that in the Wankel engine (special oil admixed with petrol). What is even more challenging, in my view, is the complete -- has to be complete for it to work at all -- sealing off of one chamber from another, while at the same time as this whirls round at high speed, it is in constant tight contact with the inside of a somewhat distorted (not a perfect circle in cross section) cylinder. So, here is the equivalent of the piston ring seal in an Otto engine, with all its early problems that implies. The distortion is yet another clever bit of design to augment/enhance the pressure fluctuation in the chambers, but that is another story. :)