Abstract: A centrifuge overspeed protection and imbalance detection system is structured to provide a method for detecting rotor imbalance and rotor overspeed. The system has a single transducer to provide real-time data necessary to detect rotor imbalance and control motor speed.Motor speed is controlled by synthesis of a drive frequency signal for driving the inverter motor control. The drive frequency signal may be inhibited to provide slow acceleration or deceleration, or to shut the motor off by providing a zero slip frequency. Motor control is responsive to a Rotor Identification circuit and operator programming, as well as a closed loop response to the real time tach signal.Imbalance detection is provided by counting tach pulses in each of a plurality of intervals, detecting deviations in tach pulse rate and sounding an alarm when the irregularity of tach pulse signals exceeds the limits of a predetermined standard deviation.

Abstract: A method of measuring an unbalance value of a wheel wherein a plurality of curves showing the relation between the magnitude of vibration of the wheel when it is rotated and the true value of the unbalance which are preliminarily obtained according to the kinds of wheel or automobile on which the wheel is mounted are memorized and compared with the magnitude of the vibration of the wheel to be tested while it is rotated. A rough value of the unbalance corresponding to the magnitude of the vibration of the wheel to be tested is obtained by using a curve M which shows the largest change of the magnitude of the vibration with respect to the true value of the unbalance. The measuring of an unbalance value is repeated with respect to the wheel on which a counter-weight corresponding to the rough value of the unbalance is attached.

Abstract: A method and apparatus is described for determining the unbalance of wheels mounted on the drive axle of an automobile by transducers detecting the forces and/or vibrations produced by the unbalance present in an automobile wheel which is jacked up for this purpose. Other equipment, in addition to the engine of the automobile, drives or brakes either of the two wheels in order to obtain a speed difference between the wheels. A measuring unit determines the magnitude and direction of unbalance. A device also determines the speeds of the driven wheels.

Abstract: Dynamic unbalance of a rigid rotor is corrected by machining the rotor in a direction parallel to the rotor axis of said rotor by subtracting or adding weights corresponding to a corrective weight in two planes for compensating initial unbalanced vectors corresponding to correction angle directions and corrective weights in the planes. Prior to effecting the machining, center of gravity position of a corrective machining weight is calculated for effecting corrective machining in the axial direction; the corrective machining corresponds to the corrective weight. The initial unbalanced vectors in the two planes are corrected into unbalanced vectors in new planes respectively including the centers of gravities of the corrective machining weights determined during the calculating step. Correction angular positions and corrective machining weights around the respective planes are obtained by repeating the calculating and correcting steps.

Abstract: Asymmetries of rotatable members such as aircraft propellers can be balanced out by the careful addition of counterweights at proper positions on the members. An accelerometer coupled to the mounting of an unbalanced rotating member produces a signal containing a component indicative of the unbalance. This signal would be useful for helping in the balancing process but it may also contain noise components from which the useful component has to be extracted without too much alteration. A fixed frequency band-pass filter could be used but the results then have to be manually corrected if the actual frequency varies from that associated with the filter or a manually turnable filter could be used but then of course the filter has to be tuned for each test.

Abstract: A first processing circuit receives signals from a vibratory acceleration and a speed of rotation and position sensor and comprises integration and filter means for providing a signal (sb) representative of the amplitude of any untrue running. A second processing circuit receives the output signal (sw) from the speed of rotation and position sensor and the signal (sb) and includes means for determining the phase difference between the signals (sw) and (sb). A memory (33) stores information representative, for different revolving systems and/or test conditions, of the difference between the measured phase difference and the angular position of an imbalance causing untrue running with reference to an origin on the revolving system. Appropriate information is read from the memory and combined with the measured phase difference in response to the actuation of selection means to provide an accurate output of the angular position of any imbalance causing untrue running.

Abstract: A device for indexing a rotor (17) of a machine (13) to be balanced utilizes the output signal (A) from a generator (15) connected to the machine rotor (17). The generator (15) produces a continuous sinusoidal output signal (A) proportional to the position and speed of the associated rotor (17). Detector means (37) detect a predetermined output from the generator (15) so that an indicator (41) issues an indication each time the detector means (37) detects the predetermined output. Thus, an operator can physically index the angular position of the rotor (17) with respect to the predetermined output (A) from the generator (15) when an indication is provided so that the position of the rotor (17) is referenced to the output signal (A) of the generator (15).

Abstract: In accordance with the invention, a magnetic field sensor is disposed on a stationary part of a centrifuge near an annular member of a rotor and is adapted to detect those variations in a gap which exists between the annular member and the sensor. The variations in the gap arising from deflection and/or precession of the rotor axis.

Abstract: A chuck is mounted to the hub of an out-of-balance wheel and an indicator stem is connected by means of a ball joint to the chuck. When the wheel is rotated and reaches a velocity such that it tends to oscillate, the indicator stem is moved to an attitude where it extends across the axis of oscillation and is balanced in this position. The rotation of the wheel is then stopped and the position of the indicator stem indicates the location where a weight is needed on the wheel and the approximate amount of weight needed at this position.

Abstract: An electronic balancing system for balancing road vehicle wheels, of the type for balancing mounted wheels, includes a processor driving a light beam projector for projecting directly on the wheel the position where a counterweight is to be attached to eliminate a condition of unbalance the value whereof is indicated on a seven-segment display.

Abstract: A balancing device for one wheel of a vehicle is disclosed which comprises a support frame, a pair of support arms pivotally mounted for horizontally and vertically pivoting on the support frame and stress sensing devices connected to the support arms for sensing a stress applied thereto. A driving unit is connected to the support frame and adapted to engage the wheel to be balanced for rotating the wheel. An apparatus for raising the support arms is provided for pivoting the support arms vertically. The support arms include vehicle engagement ends adapted to engage the vehicle and lift the wheel to be balanced.

Abstract: A process and apparatus for measurement of nonuniformity of mass of a gyro rotor having a single bearing. The gyro rotor, which is mounted in a radially fixed and spherically yielding pivot, is rotated to a predetermined speed. The static imbalance of the rotating rotor is then determined by measuring the magnitude and angular position of excursion of the rotating rotor. A force couple acting on the gyro rotor and drift of mass of the gyro rotor are determined by sensing movement of a surface of the rotating rotor at two different times. Preferably, the determination of static imbalance, force couple, and drift are obtained in a single course of measurement. After the preceding have been measured, the components of a mass balancing operation for correcting the measured nonuniformities are determined.

Abstract: A method for measuring unbalanced wheel of an automotive vehicle according to so-called "on the car" system which does not require detaching a wheel from car body for the measurement but providing car-carrying type detector under a car on the spot. In order to provide a novel method of measuring the complete dynamic balance, two detectors respectively support the car body from under an imaginary line connecting both centers of left and right wheels. Then co-related factors, l.sub.1, l.sub.2 and l.sub.3 which are distance between said two detectors, distance between one of said detectors and an inside surface of a rotating wheel and distance between said inside surface of the wheel and the outside surface thereof respectively are taken into a calculation to provide detected values of unbalance acting on said inside and outside surfaces of said left and right wheels.

Abstract: A device for measuring out-of-balance forces comprising a frame mounted on wheels, a load receiver mounted on the frame, an elongated pointer arm having one end securely fastened to the frame and a relative type pick-up mounted on the frame in communication with the free second end of the pointer. When a load is applied to the load receiver, the pick-up senses the deflection of the pointer and converts that mechanical movement into an electrical signal for measurement.

Abstract: An apparatus for determining the amount and location of unbalance in a rotating wheel of a vehicle, of the type effecting the determination of balancing with the wheels mounted on the vehicle comprising a mechanical pulse detecting means effective, when suitably positioned close to a rotating unbalanced wheel, to receive a mechanical pulse at each revolution thereof and effective to convert said mechanical pulse into a corresponding unbalance electrical pulse, an unbalance indicating means circuit connected to the detector means to receive therefrom, at each revolution of the wheel, the unbalance electrical pulse. The indicating means is effective to store the electrical pulse from the detector means corresponding to the maximum unbalance of the wheel.

Abstract: A method for remotely determining the dynamic imbalance of and for changing the spin rate and center of gravity of a spinning spacecraft which utilizes the communications channel between the spacecraft and the receiving terminal, the master index pulse generator on the spacecraft, and the spacecraft axial thrusters. To measure the dynamic imbalance, the variation in the received signal strength is plotted relative to the master index pulse. The peak-to-peak variation in the received signal strength is proportional to twice the magnitude of the wobble angle of the spacecraft created by the dynamic imbalance. The phase of the wobble angle relative to the master index pulse (MIP) is proportional to the time interval between the occurrence of an MIP and either a peak or a trough in the received signal strength. To be able to change the spin rate, the spinning body must also include a means for dynamically balancing the spinning body.

Abstract: A device for balancing a wheel mounted on a vehicle wherein the device is put in contact with the wheel by means of an adaptor cap which replaces the dust cap on the end of the wheel spindle. The wheel is driven at a high rate of speed with a probe centered relative to the end of said wheel spindle. When the heavy portion of the out-of-balance wheel moves up past true center, the probe actuates an electric switch by means of a rotor shaft, axially aligned with said probe, to complete an electric circuit to at least one indicator light of a first set of lights by means of a brush contact, fixed to the rotor shaft, for sequential engagement with a plurality of annularly disposed rotor plates. The last light to be illuminated of said first set indicates the exact location of the heavy portion.

Abstract: Rotor balancing apparatus and a system comprising balance probes for measuring unbalance at the ends of a magnetically suspended rotor are disclosed. Each balance probe comprises a photocell which is located in relationship to the magnetically suspended rotor such that unbalance of the rotor changes the amount of light recorded by each photocell. The signal from each photocell is electrically amplified and displayed by a suitable device, such as an oscilloscope.

Abstract: A jack structure is provided and includes an elevatable portion spaced centrally between a pair of stationary anchor points relative to which the elevatable portion may be elevated. The elevatable portion includes a lift member elevatable therewith and engageable with, to lift, undersurface portions of a motorcycle frame which passes beneath the engine of the motorcycle. With the front of the motorcycle frame elevated and the rear portion of the motorcycle frame supported by the retractable stand with which most motorcycles are equipped, the front wheel of the motorcycle is spaced above the ground and the jack structure further includes adjustable length bracing rods which may be anchored between the aforementioned anchor points and the handgrip portions of the handle bar of the motorcycle in order to firmly lock the handle bar and front fork assembly of the motorcycle against oscillation relative to the frame while the front wheel of the motorcycle is being spun during a wheel balancing operation.