Grinding apparatus and a method for finishing face-type commutator are shown for producing a cycloidal like grinding pattern which has a controlled depth of surface roughness established by the grain size of abrasive grit and a pitch which is controlled by relative rotational speeds of the tool and the workpiece.

Apparatus and method for finishing radial commutator

Commutators (30) of armatures (10) for electric motors or other dynamo-electric machines are finished by subjecting them to inspection (70) and turning operations (116,118). The first inspection operation determines the minimum amount of material that can be cut while producing a high quality armature. This determination may indicate that no formal turning is required, only finishing. The turning operation, if applicable, cuts the commutator (30) to a substantially cylindrical shape which is substantially concentric with the axis of rotation (12) of the armature (10). The finishing operation, which may be performed by the same mechanism as the turning operation, imparts a desired axial roughness to the cylindrical commutator surface. The commutators may be inspected after the turning and finishing operations to generate data useful for such purposes as automatically modifying the turning and finishing operations performed on subsequent commutators.

Commutator finishing methods and apparatus

A method and apparatus for creating a groove in the surface of a collector ring for use in an electrical device The method and apparatus can be used to create a new groove in the surface of a collector ring having none, or can be used to enhance or re-form an existing groove in the surface of a collector ring In some embodiments, the groove in the surface of the collector ring is created using a cutting tool that has a cutting action that functions independently from the motion of the collector ring In other embodiments, a masking material is positioned over a portion of the surface of the collector ring to create a masked portion and an exposed portion of the surface of the collector ring A groove is then created in the exposed portion of the surface of the collector ring The masking material is then removed from the surface of the collector ring

Method and apparatus for creating a groove in a collector ring of an electrical device

A portable turning tool for removing material from a worn component of a device such as a motor generator. The portable turning tool has a support member which is fixedly secured to the device in such a position so as to have a centrally located opening therein aligned with an opening formed in the support structure of the device. A rod having a cutter bit at one end and an actuator at the other end is passed through the pair of openings thereby positioning the cutter bit adjacent the worn component. By providing means on the support member for permitting the rod to slide but not rotate with respect thereto, sliding movement of the rod and thereby the cutter bit across the worn component while simultaneously rotating the component allows material to be removed from the component without disassembling the device during the turning operation.

Portable turning tool

A machine for truing the collectors or other rotating contact members of a motor, comprises a tool-holder carriage adapted to be fixed either against a brush-holder support associated with the collector or rotor, or against the face of the lower access opening of the casing of the motor, the engagement being provided by a connector coupled to the frame. Truing is effected by an abrasive stone driven in reciprocating motion along the collector. A double blowing and suction nozzle eliminates the dust. A brush and a sensor may be mounted on the carriage to eliminate the adherent dust and monitor eccentricity. The carriage is borne by a pivotable fork, by a parallelogram and by a double carriage rolling in a pit beneath the railway track.

Machine for truing electrical collectors and the like

Trueing of commutators and slip rings of large industrial motors, generators, convertors and the like without dragover of copper into insulating spaces between commutator segments or loading of surface of the trueing tool is afforded by employing an ultra-high speed grinding wheel mounted on the shaft of a precision portable electric motor mounted for traversing across the width of the contact surface. A grinding wheel in a grit range of 150 to 180 is operated at a peripheral surface speed at the grinding point of at least 7,000 feet per minute (2100 meters per minute). This speed corresponds to a 4,500 rpm rotational speed for a 6-inch. (0.1524 meter) diameter wheel. The motor and wheel are of a size and weight enabling manual mounting on a traversing compound adjacent the surface to be ground.

Thaddeus Robert Grutza

Papers

Method for trueing commutators and slip rings