A method of forming a balancing scallop within a rotating part, including inspecting the rotating part for imbalance, calculating dimensions of the balancing scallop to be formed within the rotating part, positioning the rotating part relative to a material removal machine, starting the tool removal machine, bringing the rotating part and a tool of the material removal machine into engagement, forming a first section of the balancing scallop, forming a second section of the balancing scallop, forming a third section of the balancing scallop, and dis-engaging the rotating part and the tool of the material removal machine.

A test apparatus determines the state of torsional balance of an elongate device about its longitudinal axis. It has a base plate, supporting two sets of longitudinally spaced-apart low-friction roller bearings. The second bearings are mounted on the base at a higher location than the first bearings. A support for the second bearings has a side opening to allow lateral movement of the device under test into engagement with the underside of the second bearings which resting on the upper side of the first bearings. The device under test may be a rifle or a golf putter, the barrel or shaft respectively of which is supported on the roller bearings of the first set and in contact with the underside of the second bearings. The device will rotate about the longitudinal axis if not balanced about the axis. It is very easy and convenient for the user to place the tube in the guide to check for balance whenever checking balance of the item. The side opening allows use with a variety of devices having irregular shapes along its length.

A rotor for a fluid machine includes a wheel that is supported for rotation about an axis of rotation. The wheel includes a back wall with an outer rim edge. The rotor also includes a plurality of blades that are attached to the back wall and that are spaced apart about the axis of rotation. Moreover, the rotor includes an inter-blade area on the back wall between neighboring ones of the plurality of blades. Furthermore, the rotor includes a balancing feature that is included in the inter-blade area on the back wall. The balancing feature intersects and defines part of the outer rim edge.

A rotor for a fluid machine includes a wheel that is supported for rotation about an axis of rotation. The wheel includes a back wall with an outer rim edge. The rotor also includes a plurality of blades that are attached to the back wall and that are spaced apart about the axis of rotation. Moreover, the rotor includes an inter-blade area on the back wall between neighboring ones of the plurality of blades. Furthermore, the rotor includes a balancing feature that is included in the inter-blade area on the back wall. The balancing feature intersects and defines part of the outer rim edge.

A dynamic balancing test and correction apparatus capable of shortening the time required for correcting imbalance in a correction part and improving the entire workflow of the apparatus.

A dynamic balancing test and correction apparatus capable of shortening the time required for correcting imbalance in a correction part and improving the entire workflow of the apparatus.

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 an oscillator for generating pump oscillations responsively to the drive signal and applying parametric excitation to the input oscillation at the pump oscillations.

A rotor disk for an exhaust turbocharger is mounted in a housing of the exhaust turbocharger able to rotate about an axis of rotation. The rotor disk has a disk hub comprising a disk back and a disk front remote from the disk back. A plurality of rotor disk blades are formed on the disk hub in a manner extending between the disk back and the disk front. A balancing mark is arranged in a blade channel formed between a first blade of the plurality of rotor disk blades and a second blade, arranged adjacent to the first blade, of the plurality of rotor disk blades. A width of the balancing mark is less than a length of the balancing mark. The disclosure also relates to an exhaust turbocharger comprising such a rotor disk and to a method for balancing a rotor assembly for such an exhaust turbocharger.

A rotor disk for an exhaust turbocharger is mounted in a housing of the exhaust turbocharger able to rotate about an axis of rotation. The rotor disk has a disk hub comprising a disk back and a disk front remote from the disk back. A plurality of rotor disk blades are formed on the disk hub in a manner extending between the disk back and the disk front. A balancing mark is arranged in a blade channel formed between a first blade of the plurality of rotor disk blades and a second blade, arranged adjacent to the first blade, of the plurality of rotor disk blades. A width of the balancing mark is less than a length of the balancing mark. The disclosure also relates to an exhaust turbocharger comprising such a rotor disk and to a method for balancing a rotor assembly for such an exhaust turbocharger.

A rotor for a fluid machine includes a wheel that is supported for rotation about an axis of rotation. The wheel includes a back wall with an outer rim edge. The rotor also includes a plurality of blades that are attached to the back wall and that are spaced apart about the axis of rotation. Moreover, the rotor includes an inter-blade area on the back wall between neighboring ones of the plurality of blades. Furthermore, the rotor includes a balancing feature that is included in the inter-blade area on the back wall. The balancing feature intersects and defines part of the outer rim edge.