Abstract: A method of and device for avoiding rotor instability thereby increasing the dynamic power limit of rotary fluid machines such as turbines and compressors which have contact free seals in the gaps between the rotating and nonrotating elements of the machine in which the rotary flow of fluid in the gap is modified as by axial baffles in the gap or by introducing a fluid medium into the gap thereby to decrease, eliminate, or even reverse the force component acting on the rotating element and disposed 90.degree. ahead of the oscillation deflection of the rotating element.

Abstract: A method of and devices for avoiding rotor instability thereby increasing the dynamic power limit of rotary fluid machines such as turbines and compressors which have contact free seals in the gaps between the rotating and nonrotating elements of the machine in which the rotary flow of fluid in the gap is modified as by axial baffles in the gap or by introducing a fluid medium into the gap thereby to decrease, eliminate, or even reverse the force component acting on the rotating element and disposed 90.degree. ahead of the oscillation deflection of the rotating element.

Abstract: An apparatus for raising the dynamic performance limit of steam flow and gas flow turbines and compressors, in which a non-contacting seal is arranged in a clearance between a stationary wall in the form of a ring and a rotatable member while a non-contacting seal is arranged in the clearing and supported by the ring. The seal forms a labyrinth seal and includes throttling elements. The ring is surrounded by a housing arranged in radially spaced relationship to the ring and defining therewith an annular gap. The labyrinth seal includes an active section and at least one throttling element. The ring is provided with radially extending passages located ahead of the active section of the seal and past at least one of the throttling elements. The dimensions of the passages and of at least one of the throttling elements are so selected that the major portion of the leakage flow is passed into the clearance through the passages.