Abstract: A high-vacuum molecular pump includes at least two coaxial elements (1 and 2) mounted rotatably with respect to each other and at a small distance from each other. A side of one of the elements (1) positioned opposite a side of another element (2) is provided with at least one helical groove (5), and a pump space (6) is present between these two sides of the elements, which pump space (6) is in communication with a gas supply (7) and a gas discharge (10,8). Near an end of a pair of elements (1 and 2) is a substantially annular gas supply chamber (9) which is bounded by these elements (1 and 2), the annular gas supply chamber (9) being in communication with the gas supply (7) and with the pump space (6) between the two elements (1 and 2), the helical groove (5) extending into the annular gas supply chamber (9). The elements (1 and 2) bounding the annular gas supply chamber (9) are so shaped that the annular gas supply chamber (9) is relatively wide near the gas supply (7), but narrows gradually downstream.

Abstract: Gastight seal for a rotary shaft or a cylindrical resp. cylindrical like body, the seal being of the type using a molecular gas, which seal has properties that automatically will stabilize the rotor, if whirl phenomena exited by gasforces have temporarily given rise to a precessional movement.