Abstract: The method for correcting the eccentricity of a vehicle wheel in balancing machines or the like, comprises: a reading phase for reading the radial eccentricity deviation of the rim of a wheel to be balanced and the radial eccentricity deviation of the tire of the wheel, read at a plurality of predetermined angular positions along the entire outer perimeter of the rim and of the tire; a processing phase of the total radial eccentricity deviation values of the wheel, starting with the radial eccentricity deviations of the rim and of the tire read and according to the angular coupling positions between the rim and the tire; a definition phase for defining a geometric irregularity index of the wheel, determined according to the total radial eccentricity deviation values of the wheel and according to the angular coupling position between the rim and the tire; a determination phase for determining an optimal coupling angular position between the tire and the rim, selected among all the possible angular coupling pos

Abstract: A rotating machine element is monitored for displacements using co-rotating sensors for acceleration, rotation or the direction of gravitation. In doing so, the sensor data are received by a, likewise, co-rotating electronic unit. The data can also be stored and further processed in this electronic unit.

Abstract: Embodiments described herein generally relate to a method of measuring the vibration of an aircraft engine. One embodiment herein provides an engine monitoring system either connected to and/or positioned in close proximity to an aircraft engine. Also provided is a clearance measuring device within the engine monitoring system. The clearanceometer collects clearance data that is later converted into vibration data.

Abstract: A wheel balancer for balancing a wheel having a rim and tire. The wheel balancer comprises a chassis and a driven shaft extending away from the chassis for rotating the wheel. An A&D arm, pivotal and axially extendible with respect to the chassis, is also provided. A first laser device is operable to produce a laser spot at a desired weight placement location on an inner surface of the rim. The first laser device is manipulable by an operator to move the laser spot to the desired weight placement location. A second laser device is attached to the A&D arm and movable therewith. The second laser device produces a visible marker on the inner surface of the rim for determining when the A&D arm is in a plane of the desired weight placement location.

Abstract: A wheel balancer utilizing a novel calibration technique in which the operator must only measure and enter one dimension of the tire. By requiring the operator to measure only one dimension of the tire, the probability of introducing measurement error into the system is reduced.

Abstract: A method of balancing a disk pack assembly is disclosed. The disk pack assembly comprises a plurality of components including a plurality of disks coupled to a hub of a spindle motor with at least one disk spacer between the disks. The method comprises the steps of rotating a first biasing arm about a pivot to apply a first biasing force to a first component of the disk pack assembly, and moving a second biasing arm linearly to apply a second biasing force to a second component of the disk pack assembly.

Abstract: A device for the dynamic measurement of the imbalance of a turbo rotor, which is rotatably mounted in a housing portion (6), comprises a carrier device (3), with a spring element, on which the housing portion (6) can be fastened in such a way that it has at least two degrees of freedom for oscillating relative to the carrier device, a turbine housing (4) fastened to the carrier device (3) with a channel, which is configured to supply a drive fluid and for loading the turbo rotor with the drive fluid, a free space being provided between the turbine housing (4) and the housing portion (6), a measurement sensor for detecting the oscillations of the housing portion (6), an automatic coupling mechanism (9) with a movable holder, a connection part which is held ready by the holder and can be moved by the latter up to the housing portion (6) and at least one movable coupling element, by means of which the connection part (10) can be coupled to the housing portion (6), the coupling mechanism (9) being movable into a

Abstract: A method and system for relieving forging induced residual stresses in a rotor forging balances a pre-spin machine with the forging mounted thereon at a first rotational speed and then pre-spins the forging with it mounted on the machine at a substantially greater second rotational speed. A one per rev sensor is used for determining a weight placement angle and a vibration sensor is used for determining an amount of weight to add to a spinning assembly including the forging during the balancing. High-density non-metallic balance weights adhesively attached on an inside surface of the forging or spinning assembly may be used. The rotational inertia of the spinning assembly may be checked during a spin up period by determining a rate of rotational acceleration vs. torque applied to the spinning assembly and used to stop the pre-spinning if it is to great.

Abstract: The upgraded balancing machine for vehicle wheels comprise a supporting frame for gripping and rotation means for gripping and rotating a wheel to be balanced around a rotation axis, a first sensor for detecting the unbalance of the wheel with respect to the rotation axis suitable for generating a first analog signal, a second sensor for detecting at least one portion of the profile of the wheel suitable for generating a second analog signal, at least one analog to digital converter associated with at least one of the first and the second detection sensors and suitable for converting at least one of the first and the second analog signals into a corresponding digital signal, a processing and control unit associated with the conversion device and suitable for processing the digital signal, and an adjustment unit for adjusting the sampling frequency of at least one of the first and the second analog signals associated with the conversion device.

Abstract: A method of analysing a vehicle wheel with a tyre, comprising rotating the vehicle wheel with a first number of revolutions for a first period of time, wherein a tread surface of the tyre is pressed with a first force against a first rotatable drum, the first force is measured with a first measuring device, and the first force is kept substantially constant; and rotating the vehicle wheel with a second number of revolutions for a second period of time, wherein the tread surface is pressed with a second force against the first drum or a second rotatable drum, and the second force is measured.

Abstract: A method is provided for analyzing vibrations of a variable speed rotating body. The method includes producing a signal that is proportional to an acceleration of the rotating body and producing a plurality of pulses. Each pulse represents a revolution of the rotating body and is indicative of a vibration sample at a rotational position of the rotating body. The signal is converted to a numeric value that is indicative of a vibrational amplitude of the rotating body. The plurality of pulses are converted to revolution time periods indicative of a rotational rate of the rotating body. The method also includes producing a harmonic vibrational amplitude at a harmonic of the rotational rate of the rotating body, and representing a phase of the harmonic vibrational amplitude relative to the rotational position of the rotating body.

Abstract: A method to determine eccentricity of a rotor in a turbine including: collecting sensor data of rotor eccentricity for a plurality of startup operations; establishing a baseline eccentricity value using the sensor data corresponding to a selected startup operation; determining an eccentricity value using the filtered sensor data for each of a plurality of startup operations subsequent to the selected startup operation; determining a rotor eccentricity difference between the baseline eccentricity value and each of the eccentricity values for the plurality of startup operations subsequent to the selected startup operation, and reporting a rotor eccentricity condition based on the rotor eccentricity difference.

Abstract: An inertial navigation system is provided. The system includes a sensor block, an outer shell that substantially surrounds the sensor block and a plurality of gas pads connected to the outer shell that float the sensor block in gas creating a near frictionless environment to allow the sensor block to rotate in all directions. Each of the plurality of gas pads is adapted to receive pressurized gas. The outer shell and the sensor block are separated by a gap created by the pressurized gas at each pad.

Abstract: Dynamically measuring the unbalance of a rotor arranged in a device housing (1) and rotating at high angular velocity, wherein the rotor is supported in a separate bearing housing (14), involves the following steps: fastening the bearing housing (14) on the device housing (1) with interposition of resiliently yielding elements (6) so that the bearing housing (14) can be moved relative to the device housing (1) in at least two spatial dimensions and the rotor is arranged in a working position in the device housing (1) suitable for driving, accelerating the rotor, measuring the vibrations induced by unbalance while the rotor rotates at a substantially normal working speed, determining the phase position of the induced vibrations to the relative position of the rotor at the measuring speeds, and using the measured vibrations and the phase position to determine the unbalance of the rotor to be compensated.

Abstract: Apparatus for measuring forces which are produced by an unbalance of a rotary member, comprising a measuring shaft (2) which is supported in a rotary mounting (26) rotatably about its axis (23) and to which the rotary member (19) is fixed for the measurement operation, and a support means (3) having force measuring sensors (4, 5) for supporting the measuring shaft (2) on a stationary frame (6), wherein the support means (3) has an intermediate frame (7) on which the measuring shaft (29) is supported in a mounting plane having a force measuring sensor (4), the intermediate frame (7) is supported on the stationary frame (6) by way of a further force measuring sensor (5) and by way of a first pair (11, 12) of support levers and pivots (15 to 18), the rotary mounting (26) is fixedly connected to a stiff holding device (29) at an axial spacing with respect to the mounting plane (8) in which the force measuring sensors (5, 6) are disposed, the holding device (29) is supported on the intermediate frame (8) by way

Abstract: A method and system for a wheel assembly service system are provided. The system includes a rotatable spindle configured to receive a wheel assembly wherein the wheel assembly includes at least a rim and a tire. The system further includes a load device configured to apply a load to the tire during a rotation of the wheel assembly on the spindle, and a controller configured to determine a first force variation vector of the wheel assembly, initiating rotation of the tire with respect to the rim, determine a second force variation vector of the wheel assembly with the tire rotated with respect to the rim, and determine a force variation of at least one of the tire and the wheel using the first and second force variation vectors. The system also outputs at least one of the determined force variation vector values.

Abstract: A method of operation of a vehicle wheel balancer system for identifying an imbalance correction weight mode which an operator desires to utilize during an imbalance correction procedure without requiring the operator to manually input or select an imbalance correction weight mode prior to beginning the placement of the imbalance correction weights. The imbalance correction weight mode is determined from operator guided movements of one or more dataset arms which identify if an operator-selected imbalance correction weight placement plane is associated with a clip-on imbalance correction weight, an adhesive imbalance correction weight, or a patch-type imbalance correction weight.

Abstract: A method for balancing motor vehicle wheels, comprising mounting the wheel onto the rotating spindle of a balancing machine, using a probe of known type, selecting balancing planes and diameters, providing the data to the balancing machine, spinning the wheel, calculating the value of imbalance, calculating an entity and angular position for balancing weights to be applied in the balancing planes and diameters previously selected by the operator; during the spinning of the wheel, measuring an acceleration time between two predetermined speeds of the wheel; calculating an imbalance threshold value and applying the balancing weight only if it is above the calculated threshold value.

Abstract: The balancing machine for balancing vehicle wheels comprises a base frame supporting a balancing spindle for balancing a vehicle wheel, a lifting device associable with the base frame and suitable for fitting and removing the wheel onto and off the balancing spindle, and a protection guard associable with the base frame and suitable for covering the wheel fitted on the balancing spindle, the lifting device and the protection guard being integrated together in a multifunctional device.

Abstract: Provided is a dynamic balancing apparatus using a simple harmonic angular motion, including a rotational shaft on which a rotational body having an unbalanced mass is installed; a simple angular motion generator for periodically vibrating the rotational shaft; a support for supporting both sides of the rotational shaft; an angular vibration measuring sensor for measuring the simple harmonic angular motion of the rotational shaft; and force or vibration transducers for measuring applied force acting on or vibration transferred to the support by means of the simple harmonic motion of the unbalance mass.

Abstract: An imaging tomography apparatus, in particular an x-ray tomography apparatus or an ultrasound tomography apparatus, has a stationary unit with a sensor for measurement of an out-of-balance condition of an annular data acquisition device rotatable around a patient opening in the stationary device. Compensation weights for compensation of the out-of-balance condition are provided on the data acquisition device. To simplify the balancing procedure, the compensation weights are disposed in two parallel planes axially separated from one another, and in each plane at least three compensation weights are fashioned as chambers that can be filled with a fluid. At least two of the chambers are connected with one another via at least one conduit for fluid transfer therebetween exchange.

Abstract: A machine for balancing vehicle wheels, such wheels including a rim with a pair of axially spaced, ring-shaped or annular, flanges, and a tire seated up on the rim. The machine includes a frame with motor driven devices for gripping the vehicle wheel to be balanced and rotating same about a horizontal axis. A mechanical feeler, or probe, determines the position of the first of the pair of , flanges on the rim. A contact-less, or remotely spaced, sensor, such as a laser, ascertains the profile of the tire by taking a series of discrete measurements without touching the tire. The mechanical feeler, or probe, and the contact-less sensor, are connected to a control unit in the machine. The control unit interpolates the values provided by the mechanical feeler and the contact-less sensor, and determines the location of the second flange on the wheel rim.

Abstract: The method for correcting the eccentricity of a vehicle wheel in balancing machines or the like, comprises: a reading phase for reading the radial eccentricity deviation of the rim of a wheel to be balanced and the radial eccentricity deviation of the tire of the wheel, read at a plurality of predetermined angular positions along the entire outer perimeter of the rim and of the tire; a processing phase of the total radial eccentricity deviation values of the wheel, starting with the radial eccentricity deviations of the rim and of the tire read and according to the angular coupling positions between the rim and the tire; a definition phase for defining a geometric irregularity index of the wheel, determined according to the total radial eccentricity deviation values of the wheel and according to the angular coupling position between the rim and the tire; a determination phase for determining an optimal coupling angular position between the tire and the rim, selected among all the possible angular coupling pos

Abstract: A midlength balanced rotor comprises a rotor assembly for rotation about an axis of rotation defining at least one of an axially extended, radially concentric, centerline borehole; an array of radially or tangentially distributed, axially extended pockets; and a series of radially or tangentially distributed, axially extended slots. At least one balance weight is positioned within at least one of the axially extended, radially concentric, centerline borehole, the array of radially or tangentially distributed, axially extended pockets, or the radially or tangentially distributed, axially extended slots to balance the rotor assembly. Alternatively, at least one balance correcting mass is removed from at least one of the axially extended, radially concentric, centerline borehole, the array of radially or tangentially distributed, axially extended pockets, or the radially or tangentially distributed, axially extended slots to balance the rotor assembly.

Abstract: A device according to the invention for performing vibration measurements on a test part that has a rotor, especially a transmission, includes a base structure, on which a fastening device for the test part is arranged, and a vibration measuring device for measuring vibrations caused by a rotation of the rotor of the test part. According to the invention, a balancing device is provided, arranged on the base structure or at least partially integrated into the base structure, for identifying and/or eliminating an imbalance in the rotor. The device of the invention thus enables both a balancing of the rotor and the performance of vibration measurements on the rotor, using a single device.

Abstract: Certain exemplary embodiments provide a rotating machine assembly comprising a rotor machine assembly including a shaft, a plurality of laminations shrink fit around the circumference of the shaft, and weights affixed therebetween the laminations for balancing the rotating machine assembly.

Abstract: Methods and systems for a computer implemented method of analyzing a vehicle wheel assembly including a tire and a rim is provided. The method includes removably mounting a wheel assembly on a shaft having a longitudinal axis and being rotatable about the longitudinal axis to rotate the wheel assembly, applying a substantially radial force to the wheel assembly during rotation thereof, and measuring variations in the radial force from at least one of radial runout, tire uniformity, and tire flatspotting. The method also includes determining a condition of the wheel assembly based on a spectral density analysis of the measured variations.

Abstract: Provided herein is an apparatus for detecting vibrations in a machine tool having a rotor portion (2) which is provided with tool members (5) and defines an axis of rotation (2a), the apparatus comprising a sensor assembly (3) which is able to rotate together with the rotor portion (2) and is designed to issue signals correlated to the vibrations, and a supporting and amplification device (6) for supporting the sensor assembly (3) and for amplifying the vibrations, which is set between the sensor assembly (3) and the rotor portion (2) and has a rotational asymmetry about the axis of rotation (2a) for any angle smaller than a full circle.

Abstract: In a method and apparatus for balancing a vehicle wheel, the wheel when fixed to a main shaft of a balancing machine, after the implementation of a wheel unbalance measuring run, is stopped at a given rotational angular position for a balancing operation to be carried out on the wheel, by braking of the rotary movement of the wheel. When the wheel is in the stopped condition, a braking moment derived from the unbalance measurement result and applied by a holding brake is caused to act on the wheel so that the wheel is prevented from rotating of its own accord by virtue of its static unbalance.

Abstract: A method for balancing motor vehicle wheels, comprising mounting the wheel onto the rotating spindle of a balancing machine, using a probe of known type, selecting balancing planes and diameters, providing the data to the balancing machine, spinning the wheel, calculating the value of imbalance, calculating an entity and angular position for balancing weights to be applied in the balancing planes and diameters previously selected by the operator; during the spinning of the wheel, measuring an acceleration time between two predetermined speeds of the wheel; calculating an imbalance threshold value and applying the balancing weight only if it is above the calculated threshold value.

Abstract: A three-dimensional balance assembly is provided. The assembly includes a center shaft, two or more eccentric weighted shafts encompassing the center shaft and a first and a second locking mechanism that lock each weighted shaft into any rotational location. Each eccentric weighted shaft includes at least one eccentric weight. The two or more eccentric weighted shafts are independently rotatable around the center shaft to balance the assembly in two dimensions. The center shaft includes a first and a second bore extending inwardly from each end of the center shaft or a single bore all the way through the shaft. The first and second bores are adapted to receive and secure one or more axial weights and balance the assembly in a third dimension.

Abstract: A device for holding a constructional unit (40) of a double clutch in a balancing machine, wherein the constructional unit (40) comprises a clutch cage (41) to be balanced, with a pivot bearing (45) and driving disks (46, 47), and contains a bearing mandrel (1), which has a first clamping device (24) for clamping the pivot bearing (45) rotatably bearing the clutch cage (41) to be balanced and a second clamping device (11) for clamping the driving disk (47). One of the clamping devices (11) is adjustable in respect of the bearing mandrel (1) in the axial direction by means of an operating device (22). The bearing mandrel (1) additionally has a third clamping device (29, 57) for clamping the driving disk (46), which is stationary or adjustable in respect of the bearing mandrel (1) in the axial direction by means of an operating device (34).

Abstract: A method of reducing vibration in equipment having first and second mechanically connected subassemblies is disclosed. A sensor is disposed on the first subassembly. A vibration from the sensor is recorded. The vibration is attributable to a composite mechanical operation of the first and second subassemblies of the equipment. The vibration data representative of the vibration is provided to a remote system for vibration analysis. A system for performing vibration analysis of equipment having first and second mechanically connected subassemblies is disclosed. A sensor is adapted for mounting to the first subassembly. The sensor is capable of recording a vibration attributed to a composite mechanical operation of the first and second subassemblies of the equipment. A recorder is coupled to the sensor. A vibration analyzer receives the vibration data and performs vibration analysis of the equipment from the vibration data.

Abstract: In a method for testing the thermally induced unbalance of a rotating machine part, in particular the rotor of a turbogenerator, the rotating machine part or the rotor balanced at normal temperature is brought in the demounted state first to nominal rotational speed and held at this, while its temperature is varied and, at the same time, the transient variations in oscillations of the rotating machine part or rotor which are caused are measured. During the test, the rotating machine part or the rotor is surrounded at least partially by a closed heating cell, a cooling medium flows around and/or flows through the rotating machine part or the rotor in the heating cell, and the heating of the rotating machine part or of the rotor takes place essentially due to the flow-dynamic losses arising from the interaction of the rotating machine part or of the rotor with the circulating cooling medium.

Abstract: A mounting structure of a shaft to be tested (the propeller shaft) to a balancer discloses: a centering shaft provided on a center axis of the mounting surface plate which can be fitted to a bearing provided on a center axis of the flexible coupling, wherein the flexible coupling and the mounting surface plate can be faucet connected by one of a plurality of bolt mounting portions provided at a plurality of positions in a peripheral direction of the flexible coupling.

Abstract: A method and an apparatus for determining geometrical data of a motor vehicle wheel 2 mounted rotatably about an axis of rotation 1, in which in at least two planes 19, 20 which are perpendicular to the axis of rotation 1, the distances of a plurality of measurement points on a respective periphery of the corresponding part of the wheel (wheel rim 9) from a reference location 5 and the rotary angle positions of the respective measurement points are measured and the position of the motor vehicle wheel 2 with respect to the axis of rotation 1 is determined from the measurement values.

Abstract: The device for detection of an oil unbalanced mass inside the rotor of a machine includes a device configured to entrain oil present in the rotor in rotation, such that the oil rotation speed is practically the same as the rotation speed of said rotor.

Abstract: A method of balancing a rotary device (12,14) for balanced rotational operation when connected to a drive shaft (24) by a flexible coupling (26,28). The method comprises the steps of connecting a drive shaft simulator (32,34) to a rotary device (12,14) and, rotating the said device (12,14) to simulate drive shaft unbalance due to misalignment of the rotary device (12,14) and the drive shaft (24) being simulated when the drive shaft (24) and rotary device (12,14) are connected together.

Abstract: A tire uniformity machine having a framework for receiving a tire to be tested, a rotatable chuck located within the framework and having a spindle driven by a motor directly coupled to the spindle to selectively cause rotation thereof, whereby the tire is chucked within the chuck assembly and caused to rotate by the motor. The motor is disposed in axial alignment with the spindle.

Abstract: Apparatus and method for measurement of any unbalance of a motorcycle wheel, having a rotatable main shaft of a wheel balancing machine having an electrical drive, a clamping shaft fixed coaxially with the main shaft and on which the motorcycle wheel is rotatably mounted on its bearings, a driver device which is connected in a non-rotational manner to the main shaft to transmit a torque, produced by the electrical drive, from the main shaft to the motorcycle wheel which is rotatably mounted on the clamping shaft, and a measurement device which, in one measurement run, measures forces from any imbalance of the motorcycle wheel at the measurement rotation speed, where the non-rotational connection between the driver device and the motorcycle wheel can be detached by means of an inertial force, which acts on the driver device and is formed by a torque impulse that is transmitted via the main shall.

Abstract: The present invention provides a method and apparatus for balancing vehicle driveshafts. One embodiment of a method according to the present invention comprises analyzing a driveshaft and determining a balancing vector to counter any imbalance in the driveshaft. A determination is then made of the appropriate location on the driveshaft for mounting a weight to counter said imbalance and the weight is mounted to the driveshaft. An apparatus for balancing a driveshaft according to the present invention comprises one or more primary balancing weights capable of being mounted to pinion flange holes in a vehicle driveshaft. One or more secondary balancing weights are also included, each of which is capable of being mounted to, or held by, one of the primary weights. The primary weights and secondary weights are mounted to the pinion flange to provide a weight to counter any imbalance in the driveshaft.

Abstract: A drive location compensation system determines a deviation between an actual and nominal position of a drive location on a rotor relative to an attachment location on the rotor. The compensation system uses a balancing machine and a sensor that detects when one of the attachment locations passes a known position. Based on the output of the sensor and a known position of a drive spindle of the balancing machine that is coupled to the drive location on the rotor, a relation between the drive spindle and the attachment location is determined. This relationship is compared to a nominal relationship that is based on a calibration standard. The deviation is compensated for during the balancing or the rotor.

Abstract: A method and apparatus accurately measuring the amount of unbalance of a disc, based on the time to reach a target RPM (Rotation Per Minute) regardless of an assembly condition of a disc drive. The method includes: storing a plurality of reference disc unbalance values; measuring an RPM (Rotation Per Minute) of the disc; comparing the measured RPM with a target RPM; and when the measured RPM reaches the target RPM, detecting a reference disc unbalance value among the plurality of reference disc unbalance values based on an elapsed time to reach the target RPM. Accordingly, the amount of disc imbalance of the disc can be constantly measured regardless of an assembly condition of the disc drive and the computer.

Abstract: Balancing machine comprising a shell or frame (3) suspension-mounted on a bed (2) via elastic supports, a shaft (8) rotatably supported by said frame at two points spaced a predetermined distance apart and having that end emerging from the bed provided with means (80) for locking a wheel (11), drive means for rotating said shaft, and force transducer means (33) applied between the bed and the shaft, characterised in that the drive means are rigid with the suspension-mounted frame, between the bed (2) and frame (3) there being interposed an elastic support comprising at least two coplanar leaf springs (4, 5) symmetrical about the shaft axis and positioned in a plane perpendicular to the plane containing the axes of said drive means, of said shaft and of said transducer means.

Abstract: A method and system for balancing a rotating machinery that operates at or near resonance during its normal operating speed, and which has three separate shafts whose axes of rotations are not aligned along a common axis of rotation and counterweights connected near the ends of each of the shafts. The method includes obtaining speed and vibration data, by mounting velocity transducers on the machine's inner frame and outer casing. A data acquisition system is used to collect and analyze the speed and vibration data for steady state and transient operations. The method further includes adjusting the counterweights using a predetermined rotor influence coefficient determined experimentally using the same setup of transducers, to reduce vibrations below an acceptable level. The data is collected from measurement locations where the number and positions of the measurement locations are less than and different from the number and locations of the correction planes.

Abstract: A vehicle wheel balancer obtains data relative to the imbalance of a vehicle wheel. The wheel balancer includes a rotatable shaft having a free end adapted for extending through a center hole of the wheel, and a proximal end opposite the free end. A locating hub is carried on the shaft, and is adapted for engaging a first side of the wheel to locate the wheel on the balancer. A centering sleeve is carried on the shaft adjacent the locating hub, and is adapted for extending through the center hole of the wheel to center the wheel relative to the shaft. The centering sleeve is releasably locked onto the wheel balancer, such that the centering sleeve remains secured to the wheel balancer upon removal of the wheel from the shaft.

Abstract: A high-accuracy wheel spacer is used in an off-vehicle wheel servicing machine. The servicing machine includes an elongated mounting shaft operatively connected to a drive motor and extending outwardly from a motor housing. A face plate is fixed to the mounting shaft proximate the motor housing and cooperates with a clamping assembly to sandwich and dynamically center the vehicle wheel on the shaft. The wheel spacer includes a base having first and second opposing major surfaces. A plurality of outwardly-projecting spacer pins depend from the first major surface of the base, and are adapted for engaging a limited surface area of the face plate.

Abstract: A method of balancing a rotary device (12, 14) for balanced rotational operation when connected to a drive shaft (24) by a flexible coupling (26,28). The method comprises the steps of connecting a drive shaft simulator (32,34) to a rotary device (12, 14) and, rotating the said device (12, 14) to simulate drive shaft unbalance due to misalignment of the rotary device (12, 14) and the drive shaft (24) being simulated when the drive shaft (24) and rotary device (12, 14) are connected together.

Abstract: A method and apparatus accurately measuring the amount of unbalance of a disc, based on the time to reach a target RPM (Rotation Per Minute) regardless of an assembly condition of a disc drive. The method includes: storing a plurality of reference disc unbalance values; measuring an RPM (Rotation Per Minute) of the disc; comparing the measured RPM with a target RPM; and when the measured RPM reaches the target RPM, detecting a reference disc unbalance value among the plurality of reference disc unbalance values based on an elapsed time to reach the target RPM. Accordingly, the amount of disc imbalance of the disc can be constantly measured regardless of an assembly condition of the disc drive and the computer.

Abstract: Method and apparatus for determining the rotational direction of a rotatable article, such as a spindle motor used in a data storage device to rotate a data recording disc. The article includes an index mark which is detected by an index sensor to identify an index reference position on the article. The index sensor and index mark are further used to detect the direction of rotation of the article. In some embodiments, a second sensor is provided so that first and second timing pulses are generated from the index mark by the index sensor and the second sensor. In other embodiments, a second (detection) mark is added to the article so that first and second timing pulses are generated by the index sensor. In either case, a rotational direction detection circuit determines the rotational direction of the article in relation to the first and second timing pulses.