Abstract: A method of and a system for reducing an excessive amplitude of unbalance vibration occurring in a rotor by actually measuring and comparing the unbalance vibration amplitude of the rotor with a desired level for judgement as to whether the desired value is exceeded, selecting a certain correction plane combination in accordance with the measured unbalance vibration amplitude. A correction mass to be added to the rotor is calculated using an influence coefficient corresponding to the selected correction plane combination, assuming that the correction mass is added to the rotor, estimated residual vibration amplitudes and root mean squares thereof are calculated at respective correction plane position combinations each having at least any two of positions of a plurality of correction planes on the rotor.

Abstract: A vibration diagnosis method and apparatus for rotary machines adapted for measuring the vibration of rotor shaft of a rotary machine, extracting the vibration component synchronous with the revolution of the rotor shaft from the measured vibration data, comparing the amplitude of the extracted vibration component with the amplitude of the overall vibration, analyzing the causes of the synchronous vibration component when the result of the comparison meets a predetermined reference, judging, in accordance with the result of the analysis, whether the vibration due to mass unbalance is attributable to an abrupt generation of mass unbalance or to a thermal bow of the rotor shaft, and displaying the result of the judgment. The analysis of the vibration component is made in real time or making use of data stored in the past.

Abstract: A vibration diagnosis method for a rotary machine is disclosed. The presence or absence of a self-excited vibration is determined by checking if a rotating speed is in a rotating speed range which allows the occurrence of the self-excited vibration, if an amplitude of a frequency component corresponding to a first order critical speed is larger than a predetermined level, and if phases at characteristic points of vibration signals change among cycles.

Abstract: A method and apparatus for diagnosing a vibration in a rotor of the rotary machine including detecting the number of rotations and the vibration in the rotor when the rotor is rotating, extracting a vibration component synchronized with the number of rotations, determining whether the vibration component is normal or abnormal, calculating an abnormal vibration component through a vector operation by using the detected vibration component and a previously determined rotor vibration component in a normal state of the rotor, when the detected vibration component is judged to be abnormal, normalizing a vibration pattern of the abnormal vibration component, and determining an unbalance originating position in the rotor, which generates the abnormal vibration, by using a comparison of the normalized abnormal vibration pattern with a normalized vibration pattern of a previously determined unbalanced vibration.

Abstract: A wheel or rotor with a plurality of blades arranged at irregular or unequal pitch angles circumferentially of a disk, a hub or the like, wherein the characteristic level e.sub.k representative of the order-of-harmonic characteristic of blade pitch is defined bye.sub.k =10 log.sub.e d.sub.k +100where ##EQU1## Z=a number of blades k=1,2, . . . and n; n.gtoreq.Z.theta..sub.j =the angular position of the tip or root of each blade defined in terms of a central angle subtended at the center of a circle, which is the axis of said wheel or rotor, by an arc extended from a reference point on said circle to said tip or root of each blade on said circle, j=1,2, . . . and Z; andthe characteristic level e.sub.k satisfies the following conditions ##EQU2## where e=-13.14 log.sub.10 Z+99.70k=2,3, . . . n.

Abstract: Steam introduced into a turbine casing from a steam inlet is longitudinally divided and each divided steam portion flows in respective first stages which are disposed on the shaft adjacent to each other. The shaft and a plurality of disks which are manufactured independently are made integral by a thermal shrink. In order to reduce the thermal distortion effects on the shaft caused by keys interconnecting the disks and shaft, first key grooves formed on an outer surface of the shaft and an inner surface of the disks of one first stage and a first key closely disposed in the first key grooves are arranged in symmetry with respect to the center of the shaft, to second key grooves formed on an inner surface of the disk of the other first stage with a second key closely disposed in the second grooves. Other preferred embodiments include dummy grooves and keys to balance the thermal distortion effects of the keys interconnecting the disks and shaft.

Abstract: A balancing method for use in a multiple-span rotor shaft system for a prime mover, such as a large-capacity, large-sized steam turbine and generator. A balancing influence coefficient representing the relationship between a unit weight and the resultant vibration, when the aforesaid unit weight is attached to a given balance-correcting plane of a multiple span rotor, is first determined, and then a balance-correcting plane, to which is to be attached a balancing weight, is selected, then a balancing weight is determined so as to minimize the value of the residual vibration amplitude, by using the method of least squares, which values are dependent on the value of the vibration amplitude, influence coefficients and balancing weights. Thus, a weight corresponding to the aforesaid balancing weight is attached to the aforesaid balance-correcting plane to reduce vibrations in a shaft.

Abstract: A vane pump comprising a cylindrical pump chamber, vanes adapted to rotate within the pump chamber, and a drive rotor arranged eccentrically with respect to the center of rotation of the vanes, such vane pump being formed with through holes in portions of opposite end walls of the drive rotor which are in spaced juxtaposed relationship with side end faces of each vane, such through holes being connected to a line for supplying therethrough a portion of the fluid discharged by the vane pump. During operation of the vane pump, the portion of the fluid discharged by the pump and supplied through the line is ejected through the through openings against the side end faces of the vanes so as to avoid collision between the end walls of the drive rotor and the side end faces of the vanes whereby the service life of the vane pump can be increased.