A method is disclosed for balancing the fan rotor (10) of a turbine engine having a hub (12) with blades (16) extending radially therefrom. In the preferred embodiment the method includes the steps of determining (30) a penalty associated with each possible unique blade arrangement in which a limited number of blades is relocated from their initially assigned locations on the hub to new target locations. A subset of these arrangements is selected (34), the subset members being the arrangements having the lowest penalties. For each member of the subset, the penalty determination (36) is made for each possible unique blade arrangement in which a limited number of blades is relocated from their initial locations in each subset member to new target locations. If these latter penalty determinations identify an arrangement having a penalty less than that of any arrangement in the subset, the subset selection (34) and penalty determination steps (36) are repeated until no further reduction in penalty is observed. Once a blade arrangement having the smallest penalty is identified, the imbalance associated with that arrangement is compared (42) to a predetermined imbalance limit. If the imbalance is no greater than the limit, the blades (16) are deployed (44) on the hub in accordance with that arrangement.

Method of balancing a bladed rotor

A novel system for determining the magnitudes of loads on rotating helicopter components from signals remotely measured on the helicopter fuselage is characterized by a processor which decomposes the measured signals into corresponding Fourier components and extracts selected components therefrom. A programming module performs a multiplication on the respective Fourier components to correlate the measured components with corresponding determinative parameter values. The parameter values are established in a calibration process which is characterized by determination of the independent values of a measured signal set using a Jones orthogonalization process. The signals output from the coefficient programming module are provided to a multiplying resolver which receives synthesized reference sinusoids from a digital processor and generates time dependent signal components therefrom. These signals are ultimately summed in an analog summer circuit whose output signal corresponds to the desired parameter signal.

An automatic load monitoring system with remote sensing

The invention described here provides a method for obtaining the "best" solution to balancing engine vibration where one or more corrective weights are applied to accessible stage of an engine, while other unbalanced stages remain inaccessible, and hence, no balancing weights can be applied there. The method involves placing balancing weights at accessible stages only, but taking into account vibration at such stages which is created by unbalances at the inaccessible stages. The method is practiced by calculating the angular limits for placing a corrective weight onto an engine stage, followed by calculating the minimum and maximum weight magnitude to be placed on the stage so that overall engine vibration remains below a certain desired level (D). Thereafter, the optimum weight and angular position is determined by minimizing D via a procedure of incremental calculations.

Method for balancing rotating machinery

A system and a method for determining an angular position of a rotor and a radial position of the rotor are provided. The rotor has either a slot or a protrusion on the rotor. The rotor is centered about a center point. The method includes generating a first signal utilizing a first sensor disposed proximate the slot or protrusion of the rotor. The method further includes determining a first angular position of the rotor by identifying a first corrupted portion of the first signal. The method further includes removing the first corrupted portion of the first signal to obtain a second non-corrupted position signal. The method further includes determining a first radial coordinate of the center point of the rotor based on the second non-corrupted position signal.

System and method for determining an angular position of a rotor and a radial position of the rotor

This invention provides a method to measure and determine the unbalance of a rotor, by decoupling the unbalance of the balancing machine and the unbalance of the rotor, which includes the following procedures: make the zero angle reference on the rotor or on the balancing machine, select two planes on the rotor, and use a balancing machine to measure the unbalances of the rotor in the two planes, these unbalances are designated as first nominal unbalances. The first nominal unbalance is the vector sum of the balancing machine unbalance and the rotor unbalance at the respective plane. Rotate the rotor with respect to the balancing machine with a certain angle, and remake the zero angle reference point by rotating the same angle but in the direction against the rotor's rotating direction; Use the balancing machine to measure the unbalances of the rotor in the two selected planes, the unbalances measured are designated as second nominal unbalances. The second nominal unbalance is the vector sum of the unbalance of the balancing machine itself and the unbalance of the rotor but being rotated with the certain angle at the respective plane. In the first nominal unbalances and the second nominal unbalance, the unbalance (amount and angle) of the balancing machine itself is the same, while the rotor's unbalance amount keeps the same, but the unbalance angle changes the above rotated degrees.

Method for determining unbalance amounts of rotor

Mechanical vibration of a rotating test body is translated into a periodic signal which represents a combined vector of the unbalance means of the rotating body and the mechanism that rotates it. The periodic signal is divided into two orthogonal vector components. The magnitude of the two vector components are converted into digital signals and applied to a computer. Unknown values of four constants are determined by a preliminary test having three successive stages. In the first and second stages the test body is rotated to register the digital signals; in the second state the angular position of the test body is displaced a predetermined amount with respect to its first stage position. In the third stage of the test, a trial dead weight of a known mass is mounted on the test body and rotated to register the digital signals. The computer operates on the registered digital signals to determine the four constants in accordance with a set of equations. After the preliminary test, the data registered in the first stage of the preliminary test is substituted into another set of equations using the four constants to determine the dynamic unblance mass and its angular location.

Method and apparatus for digitally analyzing dynamic unbalance of a rotating body

PURPOSE:To eliminate personal error for reading and to facilitate for the quantity of unbalance to couple with an automatic corrector by a method wherein the quantity of unbalance and the data of angle are digitally indicated and are output to the outside. CONSTITUTION:A numeric indicator 10 to indicate the quantity of unbalance including floating points and an indicator 11 to digitally indicate the angle of unbalance are installed. Rotating a drive motor 18 causes the rotating shaft 22 to rotate by pulleys 19, 21 and belt 20. The rotating shaft 22 is supported to the machine body by bearing 23, vibration frame 24 and springs 25. The rotating shaft 22 has an adapter to attach a test body 26, an angular scale plate 28, an angular reference signal 29, etc. A vibration detector 30 detects vibration ocurring to the bearing 23 caused by unbalance of the test body 26 and unbalance of the rotating shaft 22 and its attachment, which the drive motor 18 rotation generates.

Akira Ihara

Papers

Method and apparatus for digitally analyzing dynamic unbalance of a rotating body

Digital type dynamic balance measurement device