An unbalance measuring device, includes two spaced-apart workpiece receiving devices for rotatably receiving a workpiece, the unbalance of which is to be measured, and at least one sensor for detecting a vibration of the workpiece during the rotation, wherein the workpiece receiving devices each have a connection device for the positionally fixed fastening, and a workpiece receptacle for the rotational receiving, of a workpiece portion, wherein a spring device is in each case arranged between the connection devices and the workpiece receptacles.

A system dynamically balances a rotating body. The system includes a support that holds the body as it rotates. At least one sensor generates signals indicative of a balance of the body as it rotates and a controller identifies a position on the body where material can be placed to balance the body. The controller operates at least one actuator to move a plurality of ejectors opposite the identified position where the controller operates at least one ejector in the plurality of ejectors to eject material onto the identified position. The system can operate iteratively until the body is balanced within a predetermined range.

A system dynamically balances a rotating body. The system includes a support that holds the body as it rotates. At least one sensor generates signals indicative of a balance of the body as it rotates and a controller identifies a position on the body where material can be placed to balance the body. The controller operates at least one actuator to move a plurality of ejectors opposite the identified position where the controller operates at least one ejector in the plurality of ejectors to eject material onto the identified position. The system can operate iteratively until the body is balanced within a predetermined range.

An arithmetic processing unit of a balance inspection apparatus generates three-dimensional point cloud data based on measurement results of surface shape measuring parts, generates surface data based on the three-dimensional point cloud data that have been aligned with a surface shape model defined in a coordinate system in which a designed rotation center axis of a crankshaft is an X axis, extracts evaluation object data, which are surface data of an evaluation object portion including an arm of the crankshaft, calculates gravitational centers and areas of cross sections orthogonal to the X axis at a plurality of positions along the X axis of the evaluation object data, calculates a gravitational center and a weight of the evaluation object data based on the gravitational centers of the cross sections and predetermined weights set according to the areas of the cross sections, and calculates an imbalance amount of the crankshaft.

An arithmetic processing unit of a balance inspection apparatus generates three-dimensional point cloud data based on measurement results of surface shape measuring parts, generates surface data based on the three-dimensional point cloud data that have been aligned with a surface shape model defined in a coordinate system in which a designed rotation center axis of a crankshaft is an X axis, extracts evaluation object data, which are surface data of an evaluation object portion including an arm of the crankshaft, calculates gravitational centers and areas of cross sections orthogonal to the X axis at a plurality of positions along the X axis of the evaluation object data, calculates a gravitational center and a weight of the evaluation object data based on the gravitational centers of the cross sections and predetermined weights set according to the areas of the cross sections, and calculates an imbalance amount of the crankshaft.

A system dynamically balances a rotating body. The system includes a support that holds the body as it rotates. At least one sensor generates signals indicative of a balance of the body as it rotates and a controller identifies a position on the body where material can be placed to balance the body. The controller operates at least one actuator to move a plurality of ejectors opposite the identified position where the controller operates at least one ejector in the plurality of ejectors to eject material onto the identified position. The system can operate iteratively until the body is balanced within a predetermined range.

A system for converting an input oscillation having an input frequency into an output oscillation having an output frequency is disclosed. The system comprises: a controller configured for receiving the input oscillation and responsively generating a multi-component drive signal. A frequency of at least one component of the drive signal is other than two times the input frequency. In some embodiments, a frequency of another component of the drive signal equals about two times the output frequency. The system also comprises n oscillator for generating pump oscillations responsively to the drive signal and applying parametric excitation to the input oscillation at the pump oscillations.

An engine trigger wheel is disclosed having a central annular portion and a cylindrical rim portion defining a number of trigger teeth, wherein the central annular and cylindrical rim portions are pressed from a single piece of metal. A number of balance apertures are formed in the central annular portion to move a center of mass of the trigger wheel away from an axis of rotation. The engine trigger wheel when fastened to one end of a crankshaft of an engine provides both an indication of the angular position of the crankshaft and a counterweight function.

Disclosed is a technique of achieving weight reduction of a forged rotary body while improving productivity of the forged rotary body. Temporary center holes are set for each of two or more samples extracted from one forging lot of a plurality of forged rotary bodies produced within a time period after a die misalignment adjustment through before a next die misalignment adjustment. Then, a virtual final shape of each of the samples is simulated on an assumption that machining is performed on the basis of the temporary center holes, and a rotational imbalance amount is calculated. Then, an average value of the rotational imbalance amounts in all of the samples in the same forging lot is calculated, and center-hole positions which allow the average value to become zero are set as center hole machining positions for all of the forged rotary bodies in a corresponding forging lot.

A dynamic balance testing device includes a vibrating unit configured to rotatably hold a predetermined rotating body being a specimen, a first spring configured to elastically support the vibrating unit and restrict displacement of the vibrating unit in a direction parallel to a rotation axis of the predetermined rotating body, and at least three second springs configured to elastically support the vibrating unit and restrict displacement of the vibrating unit in a predetermined direction orthogonal to the rotation axis. The at least three second springs are attached to the vibrating unit on a same predetermined plane, and the vibrating unit holds the predetermined rotating body such that a projection of a center of gravity of the predetermined rotating body onto the predetermined plane is substantially at the same position as a position where the first spring is attached to the vibrating unit.