In a vacuum pump, a portion of a lower end portion of a rotating cylindrical body is cut in an axial direction thereof to form an imbalance correction portion (removal portion). Preferably, the removal portion is formed so as to minimize an axial width of the rotating cylindrical body and set a circumferential width of the rotating cylindrical body to a value of not less than a thickness (width in a radial direction) of the rotating cylindrical body. Additionally, a corner formed in the removal portion is formed to have a large. With this configuration, in the rotating cylindrical body, the removal portion is formed to have a shape in which a removal width (depth) in the axial direction of the rotating cylindrical body is small and a removal width in the circumferential direction thereof is large.

A method of balancing a gas turbine engine rotor comprises the step of obtaining a rotor disc with a circumferential array of balance tabs projecting from a peripheral rim of the disc. Stress shielding scallops are defined in the rotor disc between the tabs. The balancing is achieved by removing material from at least one of the tabs.

A rocket engine propulsion system having improved engine performance is described herein. The rocket engine propulsion system includes an axial counterbalance to reduce or eliminate axial thrust exerted on components of a turbopump. The axial counterbalance can allow for a larger range of axial thrust forces while coupling this ability to a rotational speed (e.g., rotations per minute, or RPM) of a shaft. The axial counterbalance includes a protrusion on that extends circumferentially around a shaft that mates with a protrusion on a swing arm. The swing arm is rotatably attached to a bracket which is constrained by a static support.

A vibration isolation holding device includes a body portion and an abutment member. The abutment member is arranged between the body portion and a bearing housing, and has an abutment surface abutting on the bearing housing, when a cartridge is held. A biasing member is disposed between the abutment member and the body portion. An interval between the body portion and the abutment member is regulated by a first regulating portion to be shorter than a natural length of the biasing member.

A machine has: an outer member; an inner member mounted for rotation about an axis relative to the outer member; and a seal system. The seal system has: a seal housing mounted to the outer member; one or more seal rings held by the seal housing and having an inner diameter surface; and a seal runner mounted to the inner member and having a first outer diameter surface portion contacting or facing the inner diameter surface of the one or more seal rings. The seal runner has a circumferential array of mounting features. One or more weights are mounted to one or more of the mounting features.

The invention relates to a method for determining a balancing removal process for a balancing device for balancing a rotationally symmetrical component, particularly a rotor component, particularly of a turbomachine, a combination of machining lengths and depths being calculated, taking into account a pre-defined maximum machining length and minimum machining depth, in such a way that, with reliable combinations for compensating the same unbalance, the machining length of the calculated combination is longer than the machining length of at least one other permissible combination and, at the same time, the machining depth of the calculated combination is shallower than the machining depth of said other combination.

A machine has: an outer member; an inner member mounted for rotation about an axis relative to the outer member; and a seal system. The seal system has: a seal housing mounted to the outer member; one or more seal rings held by the seal housing and having an inner diameter surface; and a seal runner mounted to the inner member and having a first outer diameter surface portion contacting or facing the inner diameter surface of the one or more seal rings. The seal runner has a circumferential array of mounting features. One or more weights are mounted to one or more of the mounting features.

A turbine rotor includes a rotor body and a balancing weight slot defined in an exterior circumference of the body. The balancing weight slot has a first axial width and a first radially outward facing surface at a first radial distance from a rotor axis. The rotor also includes a balancing weight entry port defined in a portion of the exterior circumference of the rotor body and aligned with the balancing weight slot. The balancing weight entry port has a second axial width greater than the first axial width and a second radially outward facing surface at a second radial distance from the axis of the rotor body that is smaller than the first radial distance. A method may include machining the entry port into the rotor with a tool. The method may be applied to a new rotor, or to remove cracks initiating from a previous entry port.

A rotor assembly comprises a rotor having annular flange including a plurality of protrusions axisymmetrically disposed about the annular flange, each protrusion having a mounting aperture for selectively receiving a balancing feature, and a plurality of slots axisymmetrically disposed about the circumference of the annular flange between adjacent protrusions. Each slot has a pair of converging flat portions extending axially inwardly from an adjacent protrusion end, an inner flat portion at an inner end of each slot, and a pair of curved portions respectively joining each converging flat portion to the inner flat portion in each slot. Each slot has a depth at least as great as an adjacent mounting aperture depth extending normally from the adjacent protrusion end to a far end of the corresponding mounting aperture.

A turbine wheel is provided with a groove having a bottom surface and a pair of side wall surfaces. The turbine wheel includes: a balance weight that is arranged in the groove, is insertable from any circumferential position of the opening of the groove, and has a through-hole opened toward one of the pair of side wall surfaces; and a retaining member that contacts the one of the pair of side wall surfaces in a state of being inserted in the through-hole of the balance weight, to thereby cause the balance weight to abut against the other one of the pair of side wall surfaces and be retained in the groove. The groove has engagement recesses provided at intervals in a circumferential direction at the bottom surface or an engagement protrusion fitted to one of fitting recesses provided at intervals in the circumferential direction at the bottom surface and protruding from the bottom surface. The balance weight has an engagement protrusion or an engagement groove that engages with one of the engagement recesses or the engagement protrusion of the groove, to thereby restrict a circumferential shift of the balance weight in the groove.