Abstract: The powered hand tool for machining includes an enclosed drive motor having a rotor shaft and is provided with at least one interior air duct through which drawn-in cooling air passes to cool the drive motor. To prevent the drive motor from being clogged or damaged by magnetizable dust, which is produced from the machining process among other things, a permanent magnet is nonrotatably attached to the rotor shaft and also located in the air duct or ducts. The invention also resides in an air-cooled drive motor having a cooling-air flow with a permanent magnet located in the vicinity of the cooling-air flow and fixed nonrotatably to the motor shaft.

Abstract: A rotary electric machine including a stator, a rotor journalled for rotation relative to the stator about an axis of rotation and carrying electrical windings. The rotor includes a fluid inlet spaced from a fluid outlet and a cooling liquid flow path is located in the rotor interconnecting the inlet and the outlet. The liquid flow path is in heat relationship to the windings and at least a part thereof is displaced from the axis of rotation. A gas vent passage is disposed in the rotor to interconnect the inlet and the outlet and is located on the axis of rotation to thereby prevent gas bubbles tending to build from air entrained in the coolant on the axis of rotation.

Abstract: A centrifugal filter for a high speed electrical machine of the type having a fluid flow path through its rotor. The centrifugal filter includes an enlargement at the beginning of the flow path through the rotor and which extends radially outwardly of the axis of rotation. As a consequence, contaminants in an incoming fluid stream are subjected to centrifugal force during operation of the machine and moved thereby radially outwardly within the enlargement so as to be out of the fluid stream. Consequently, the fluid stream, after separation of the contaminants therefrom within the enlargement by centrifugal force, may be passed with safety through the rotor for cooling and/or lubricating purposes.

Abstract: A gas filtration system is provided for coolant systems for dynamoelectric machines which utilizes differential pressures within the machine to induce a gas flow through the system. Valves are provided to balance dual inlet flows and the filtration system utilizes an air filter, coalescing filters and gaseous containment filter in its preferred embodiment. The filtration avoids the need for additional pumping by disposing its filtering means between and in fluid communication with two or more zones having different gas pressures.

Abstract: A rotary electric machine including a stator, a rotor separated from the stator by an air gas journalled for rotation relative to the stator about an axis of rotation and electrical windings carried by at least one of the rotor and the stator. A cooling liquid flow path is provided for cooling the windings and a gas vent passage is disposed in the rotor, to open to the air gap and introduce gas into the gap, to prevent the entry of liquid coolant and/or drive accumulated liquid coolant out of the air gap.

Abstract: A filter for a cooling air stream of an electric commutator motor for a household device has a passage into which a cooling air stream flows after passing an electric commutator motor, and a filtering member composed of an electrostatically charged material which coats the passage partially or completely.

Abstract: An alternator filter arrangement which encorporates an alternator having a driven shaft passing through its housing which has an air intake therein and a non-magnetic filter screen mounted for rotation with the driven shaft with the filter screen being in close proximity to and substantially encompassing the air intake.

Abstract: An air filter assembly for a heavy duty motor vehicle generator is disclosed. The assembly includes an adaptor plate and connecting means for rigidly connecting the adaptor plate to one end of the generator. The assembly further includes a housing enclosing a chamber and an air filter element removably disposed in the chamber, the housing having a circular threaded collar threadably engaged to the adaptor plate. Through the air filter element, and apertures provided in the housing and adaptor plate cooling air flow is permitted to flow but particulate foreign matter is excluded.

Abstract: A composition is disclosed of a solution of a resinous carrier and at least two compounds which thermoparticulate at different temperatures between 60.degree. and 200.degree. C. A coating is made by applying the composition to a portion of an electrical apparatus exposed to a gas stream. As the temperature of the coating increases the compound therein thermoparticulate. The time between which the compounds thermoparticulate indicates the rate of rise of the temperature and analysis of the products of thermoparticulation indicates the location of the coating in the electrical apparatus. Alternatively, the coating can consist of several layers with a thermoparticulating compound in each layer which thermoparticulates at different temperatures.

Abstract: Sets of certain halogenated aromatic organic compounds, for example, N-alkyl tetrahalophthalimides, have been found useful as chemical tags when employed in a thermal particulating organic resin. Improved tagging performance has been achieved over extended use periods at temperatures up to 140.degree. C., if the tags are microencapsulated prior to incorporation into the particulating organic resin.

Abstract: A petroleum or synthetic grease is used to protect electrical apparatus from overheating. The grease is applied to a portion of an electrical apparatus which is exposed to a gas stream, particularly to portions subjected to operating temperatures of about 100.degree. C. When the coated portion of the electrical apparatus overheats the grease forms particles in the gas stream which are detected by a monitor. The apparatus can then be shut down or its load reduced.

Abstract: A composition is disclosed of a solution of a resinous carrier and at least two compounds which thermoparticulate at different temperatures between 60.degree. and 200.degree. C. A coating is made by applying the composition to a portion of an electrical apparatus exposed to a gas stream. As the temperature of the coating increases the compounds therein thermoparticulate. The time between which the compounds thermoparticulate indicates the rate of rise of the temperature and analysis of the products of thermoparticulation indicates the location of the coating in the electrical apparatus. Alternatively, the coating can consist of several layers with a thermoparticulating compound in each layer which thermoparticulates at different temperatures.

Abstract: In a dynamoelectric machine of the type wherein cooling air taken from outside of the machine is circulated through the housing of the machine by means of a fan and a casing containing slip rings is mounted on the outside of the housing, a portion of the cooling air pressurized by the fan is circulated through the casing for cooling the slip rings.

Abstract: A composition is disclosed of a urea compound, a resinous carrier, and a solvent. The composition is applied to a portion of an electrical apparatus which is exposed to a gas stream. The solvent in the composition is evaporated to produce a thermoparticulating coating. When the electrical apparatus overheats the urea compound in the coating forms particles in the gas stream which are detected by the monitor.

Abstract: A composition is disclosed of metallic carboxylate, a resinous carrier, and a solvent. The composition is applied to a portion of an electrical apparatus which is exposed to a gas stream. The solvent in the composition is evaporated to produce a thermoparticulating coating. When the electrical apparatus overheats the metallic carboxylate in the coating forms particles in the gas stream which are detected by a monitor.