Abstract: A split-phase starter for an electric motor having a casing made up of a casing body and a lid secured to the casing body, the casing body having a first casing and a second casing, a relay contact mechanism being arranged in the casing body, and a positive temperature coefficient thermistor being arranged in the second casing.

Abstract: Protection for an encased motor driven device is enhanced by utilizing additional sensors with associated resistance heaters to actuate the thermally responsive contacts of the internal line break. The sensors and heaters are powered from an auxiliary winding in the motor coils. When applied to a hermetic scroll compressor, the compressor can be protected against reverse rotation.

Abstract: A multi-speed electric motor (1) has a main electrical winding (3) and an auxiliary electrical winding (5) connected in parallel. One additional electrical winding (21) is connected in series with the parallel connected main and auxiliary windings, and another additional electrical winding (23) is connected in series with this third winding. A temperature sensitive resistive element (25) is connected in parallel with at least one of the additional electrical windings. The resistive element improves the motor's starting torque when one or more additional windings are initially connected in the motor circuit as it is started.

Abstract: A split phase electric motor starter and protector are shown having a housing which receives a PTC starter switch and a motor protector and provides various wiring options for connecting the PTC switch and, if desired, a capacitor to a motor depending upon the particular requirements of an application. The housing optionally accommodates a capacitor support bracket.

Abstract: A method of locating a limit switch (10) on a compressor (12) utilizes thermography for determining the optimum location thereof. A thermograph is produced for normal and abnormal operating modes of the compressor (12). High temperature gradients in the thermograph indicate high rates of temperature increase during compressor failure modes for selecting an optimum location for the limit switch. A bimetal switch (10) is utilized to establish a cut-out temperature for preventing operation of the compressor (12) and a cut-in temperature lower than the cut-out temperature for automatically closing to resume operation of the compressor (12) when returned to normal temperatures.

Abstract: An electric motor incorporates a positive temperature coefficient resistor 18 between a supply terminal and a brush. The resistor can be inserted from outside the motor through an aperture 17 in an end cap 2. A body 19 of heat conducting material, also insertable from outside the end cap, can be provided and held against to resistor 18 to alter its effective thermal mass and so adjust its operating characteristics.

Abstract: A bushing for mounting an overload protector within an opening in a motor shell comprises segments adapted to be coaxially positioned around a portion of the overload protector. Mating features formed on the segments and protector restrict movement of the protector relative to the segments. Grooves formed on the segments secure the segments within the opening and restrict movement of the bushing and protector assembly relative to the structure. The bushing preferably comprises a pair of generally symmetrical segments connected together by an integrally formed hinge. The one-piece bushing is molded from a thermoplastic material, such as nylon. In one embodiment, the features which restrict axial movements of the overload protector relative to the segments are mating threads formed on a portion of the internal surfaces of the segments, and on opposing portions of the external surface of the protector.

Abstract: A direct-current motor that facilitates the assembly and mounting of components of the motor, including a front bracket made of synthetic resin and defining recesses. A plurality of metallic brushholders are located in the recesses. The protection of the motor is improved by the waterproofing construction of the motor, including motor cords, and has a sturdy construction.

Abstract: A low power valve actuator includes a small motor that rotates an Acme drive screw. The rotary motion of the drive screw is translated into linear motion of a drive nut-traveling block, which is guided along and held against rotation by a pair of spaced parallel guide rods. A cantilever pin carried on the traveling block engages in a groove extending longitudinally of, a Scotch yoke lever, which translates the linear motion back into rotary motion at a further mechanical advantage. The Scotch yoke lever is reinforced and strengthened by reason of the fact that the groove is not a through-slot, but extends only partially through the lever arm. The device is made more compact by reason of the fact that the groove in the Scotch yoke lever can actually extend over the top of the valve stem.

Abstract: An arrangement for monitoring temperature of water discharging from a plurality of water-cooled electric coils of an electric generator includes a manifold for collecting the discharging water, a plurality of hollow tubes connected in flow communication between the manifold and the respective electric coils, and a plurality of temperature sensing assemblies interposed in the respective tubes between and in series relation and flow communication with first and second portions of the hollow tubes such that the temperature sensing assemblies are thermally isolated from the manifold by the first portions of the respective tubes and electrically isolated from the respective electric coils by the second portions of the respective tubes. Each temperature sensing assembly includes an annular sleeve clamped about ends of the portions of the flow tube for receiving and connecting in flow communication the flow tube portion ends.

Abstract: A small-sized electric motor is provided with a hole for inserting a circuit breaker in a holder base lying between a motor case and a gear case, and the circuit breaker is fixed to the holder base by inserting its own body in the hole of the holder base together with terminals at the state in which the terminals are in contact with electrical connective plates of the circuit breaker respectively, it is possible to fix up the circuit braker to the holder base of the motor by merely press-fitting and becomes possible to automate the assembly of the motor housing and the built-in circuit breaker.

Abstract: Electrical terminal pins (start, main and common) mounted in a glass header to provide electrical connection to a compressor motor are shown with a motor protector disposed on one of the pins in such a fashion that opposite-direction-oriented right angle female flag quick connectors are required for the start and main terminals, thereby avoiding the possibility of miswiring the terminal pins. The opening temperature of the motor protector is adjustable and the protector has a fail safe mechanism to avoid subjecting the motor to overtemperature conditions.

Abstract: In order to improve the handling of a temperature switch, particularly for the use and contacting thereof on a printed circuit board, the invention provides a temperature switch, such as in particular a thermostat for an electric motor with a bimetallic switch mechanism in a casing, in which the latter is provided with a shoulder having undercuts and that connecting contacts are arranged adjacent to the shoulder.

Abstract: A circuit breaker mounting section is provided for mounting a circuit breaker to a brush holder assembly in an electric motor. The mounting section is partitioned and formed so as to surround three sides of a circuit breaker with a partition wall projecting from the base plate of the brush holder assembly in a direction parallel to the axis of a motor core projecting through the assembly such that the outer surface side of the circuit breaker mounting section is open. The outer surface side opening of the breaker mounting section is surrounded and sealed by an inner side surface of a frame when the brush holder assembly is fitted and mounted in the frame.

Abstract: An electric motor comprising a stator having a plurality of radially inwardly extending circumferentially spaced polar segments. A coil is wound around each stator segment. A unitary motor overload assembly is provided and connected by a standard lead from one of the coils and by a solid uninsulated conductor lead to the other of the coils. The cross-section of the solid conductor is such that the motor will operate satisfactorily during normal running or locked rotor condition but would open by melting in the event of a winding failure of the coils which would normally result in higher than normal operating currents in the winding.

Abstract: A unipolar motor control system includes motor current regulation derived from monitoring battery voltage and motor temperature. The monitored battery voltage and motor temperature are inputs to a microprocessor control which has one or more look-up tables for developing an appropriate scaling factor that adjusts the voltage across the motor coils so that proper current magnitude is delivered to the motor.

Abstract: A miniature motor having a positive-coefficient thermistor in which a first supporting member made of an electrically conductive material and electrically connected to at least any one of a pair of brushes housed in a motor cover plate, and a second supporting member made of an electrically conductive material and electrically connected to an external terminal are provided; a positive-coefficient thermistor being supported between the first and second supporting members.This construction makes the assembly of the motor easy, leading to improved productivity, and allows the motor to have a positive overheat preventing function without adding to the number of parts.

Abstract: A miniature motor having a positive temperature coefficient thermistor comprising a stator having a permanent magnet serving as a field, a rotor formed by winding a plurality of rotor windings on a rotor core, brushes supported by a motor cover plate for feeding current to the rotor windings by making contact with a commutator, positive temperature coefficient thermistor for controlling current to the rotor windings, in which the positive temperature coefficient thermistor has one pole on one pole surface thereof, and a plurality of independent split poles corresponding to the rotor windings on the other pole surface thereof, and is fitted to an end face of the rotor core;the rotor windings being connected to the split poles of the positive-coefficient thermistor in such a manner as to be connected in series with the split poles of the positive-coefficient thermistor.

Abstract: The problem of effectively and quickly detecting fault conditions in an electromotive machine (10) is solved using a current transformer assembly (28) having a neutral lead (44). The neutral lead (44) comprises a single piece copper strap (80) having laterally extending strips or posts (81-83) provided for connection to the neutral end conductors (31-33) of armature windings (22 and 24). The strap (80) is punched and bent into shape to include the three neutral posts (81-83). Each neutral post (81-83) carries a current transformer (46-48).

Abstract: A motor-driven fuel pump comprising a pumping unit, a brushless electric motor for driving the pumping unit, a control circuit for controlling power supply to the brushless motor and a pump casing for encasing the pumping unit, the brushless motor and the control circuit. The control circuit comprises a current limiting circuit which inhibits flow to the brushless motor of a current above an amperage which is higher than an amperage of a normal operating current and lower than an amperage of a current which would flow at starting of the brushless motor without the current limiting circuit.

Abstract: A method and device for detecting a partial discharge pulse in a high voltage conductor in the stator of a motor, turbine generator or the like, comprising a conductive plate having an insulated face, an insulated signal conductor spanning the insulated face of the plate, and means for transmitting an electrical pulse produced in the signal conductor to recording means for determining the location and severity of partial discharge activity within the high voltage insulation of the conductor.

Abstract: A retention arrangement for retaining a motor cover and a thermal protection device over one end of a dynamoelectric motor uses connection bolts already available on the motor for mounting the stator and positions the protector in an annulus between the cover side wall and stator end turns and below the upward extension of the stator end turns. The retention arrangement includes a pair of plates being bolted to the motor and encircling the end turns of the stator with first interengageable portions securing the cover to the plates and second interengageable portions securing at least one plate to a holder to which the protector is mounted, such retention assuring that after the air space between the stator and rotor is set a suction duct will be positioned to cool the protection device and the end turns.

Abstract: A motor is disclosed comprising a housing and a plurality of parallel stator laminations mounted on the interior wall of the housing surrounding the rotor. The stator comprises a plurality of coils wound around the stator poles. Each coil or group of coils connected in series with each other are further connected in series with a thermistor network. Preferably, the thermistor is supported on a printed circuit board mounted adjacent to the coils, with the thermistor being inserted in a space directly adjacent to or between adjacent stator coils in order for the thermistor to accurately respond to the actual operating temperature of the coils. With increases in temperature, the resistance of the negative temperature coefficient thermistor will decrease, lowering the resistance of the motor circuit and maintaining the L/R time constant of the system. The opposite effect will occur with decreasing tempreature.

Abstract: An electric motor includes a fan attached to the end of a rotor shaft extending through an opening in an end shield of the motor housing. The fan forces air about the housing to cool the motor components. A motor protector including a temperature sensor is connected to the stator windings and is sensitive to winding temperatures to shut off the motor when the temperatures exceed a predetermined level. A performed strip of material is positioned over the protector in a tent-like form to block flow of cooling air around the protector. Thus, the protector is kept sensitive to the winding temperature, the material block preventing the protector being influenced by the flow of cooling air within the motor.

Abstract: A dc commutator motor can be switched off when the motor rotor is short-circuited by the rotor's coming to a halt, by an operating switch (10). The switch is provided in the line connecting the brushes to a radio suppression network in a compact and simple design. The switch is operated by an ac voltage induced when the motor is running, with a frequency corresponding to the motor speed. A sensing winding connected to the operating switch for inducing the operating ac voltage is wound preferably around a radio interference suppression choke of the radio suppression network.

Abstract: A dynamoelectric machine includes a stator assembly having one or more sets of electrical windings. Apparatus for electrically interconnecting external electrical leads, a thermal protector and ends of each set of windings includes a protector block for commonly connecting one end of at least one winding set with the thermal protector. The thermal protector is housed in the protector block. A terminal block interlocks with the protector block to hold the thermal protector in place. An electrically conductive arm of the thermal protector extends through the terminal block to effect connection of the thermal protector with an external lead. The terminal block also provides for connection of the other end of each winding set with another external lead.

Abstract: An automotive alternator includes a thermal switch located in a rear chamber of the alternator enclosed by the housing rear wall and circumferential intermediate wall and the stator and rotor. The thermal switch is mounted on the heat-sinking collector tab of a power transistor in the regulator. In high power, low idling conditions with poor interior ventilation, the thermal switch senses heat produced from the rectifier diodes, rotor, stator and regulator to cut-off generation in over temperature conditions. Rings are furnished on the rectifier diode posts to conduct more heat from the diode body and the stator is potted with a special double dip and bake procedure with a thin viscosity two-part epoxy material.

Abstract: An electric motor having at least two salient stator poles equipped with windings, covering members inserted into gaps between the poles, and a protector switch associated with the field windings. The protector switch is mounted at a predetermined position on one of the covering members using a clamping element which is configured as an elongated component and which is provided with a receptacle for the housing of the protector switch and a holder for leads extending from the switch. The clamping member snaps into a recess in the cover member extending in the direction of the motor axis. The clamping element orients the protector switch so as to avoid contact chatter due to vibration of the motor.

Abstract: The natural resonant frequency (and phase) of a resonant mechanical system (having an spring structure that includes a material whose elastic properties change with temperature, e.g., by at least 0.05% per .degree.C.) is tuned to a desired value by changing the temperature of at least part of the spring structure. A two-dimensional image is generated on a surface by tunign a resonant driver (having such a temperature sensitive element) to a natural resonant frequency in coordination with modulation of a beam that is raster scanned on the surface by the resonant driver.

Abstract: A temperature activated fan assembly preferably for an electric motor. The assembly includes a fan, a torque transfer means engagable with the fan for transferring torque to the fan and a first member which expands in response to a temperature increase. The expansion of the first member causes the torque transfer means to engage the fan. The first member is situated within the motor such that the first member causes the fan to operate when a critical temperature in the motor is reached. The first member can be fabricated as a rod or coil from a material having a suitably high coefficient of thermal expansion. The first member can also be fabricated from a memory material.

Abstract: A motor protector and starter particularly suited for refrigeration compressor motors are mounted in the recess of a first housing portion with their resilient female sockets disposed in alignment with a pin receiving aperture. Leads are attached to terminals of the motor protector and starter components and directed through lead receiving apertures in the side wall of the first housing portion. A second housing portion is then snapped onto the first housing portion to provide a combination housing which can be installed on a compressor in a one-step on-line operation.

Abstract: A miniature motor having a metallic case with a printed circuit board installed therein. The printed circuit board has an electronic circuit, mounted thereon, for controlling the miniature motor. A lug portion is provided protruding from the edge of an open end of the metallic case. An engaging portion is provided for engaging the lug portion with an earth terminal of the printed circuit board. The earth terminal and the lug portion are electrically joined by means of soldering in a state the printed circuit board is fitted to the metallic case in such a manner as to engage the lug portion with the engaging portion.

Abstract: An electric motor inlcudes a slotted collar on the rotor and a temperature sensitive actuator with an attached pin effective when cold to move into an inserted position in which the pin engages the slotted collar to prevent rotor rotation, and when hot to move to a retracted position in which the pin is withdrawn from the collar to allow rotor rotation. The actuator comprises first and second springs having ends connected together and exerting opposing forces on each other, the second spring being made of a temperature sensitive memory metal so as to shorten and lengthen the actuator with changing temperature. The acutator is electrically conducting and inserted in series with the motor commutator, whereby armature current heats the actuator to move to the retracted position, and cessation of armature current allows it to cool and move to its inserted position.

Abstract: A method for determining overheating in liquid-cooled windings of electric machines includes acoustically monitoring cooling liquid with at least one sound pickup, and detecting noises generated by bubbles in the event of local overheating if the boiling point of the cooling liquid is exceeded. An apparatus is also provided for carrying out the method.

Abstract: An end cap for small electric motors using brushes, the end cap being molded of a synthetic plastic dielectric material. Brush-receiving guides are defined on the end cap by homogeneous cantilevered fingers which are deflectable to grip the brush therein during assembly of the end cap to a motor casing. Electric conductor and connector retainers are homogeneously defined on the end cap to provide conductor strain relief, a circuit breaker retainer is homogeneously included in the cap configuration, and tie bolt ears are of such configuration as to cooperate with the motor casing to resist deflection.

Abstract: A motor comprising a small case having at the center thereof a cylindrical bearing housing for housing a bearing, and at the edges thereof holes through which brush holders receiving and supporting motor terminals connected to brushes extend. A large case forming a motor housing, a earth plate comprising a base having at the central part thereof a contacting and mounting hole into which the bearing housing is inserted and press-fitted, a neck extending from the base flush therewith, an arm extending from the tip of the neck at right angles to the plane of the neck and being inserted into a motor terminal hole on one of the brush holders and a contacting curved portion for making electrical contact with the motor terminal. The earth plate is installed onto the small case by press-fitting the base from the outside to the bearing housing, and press-fitting the arm into the motor terminal hole so as to make electrical contact with the motor terminal.

Abstract: Snap action thermostat has a housing molded onto two flat terminals to form a cavity wherein inner portions of the terminals are exposed. A contact arm is welded to the inner portion of one terminal, a dished bistable bimetal element is placed loosely in the cavity, and a fulcrum plate is provided thereover to bias the bimetal element against the contact arm in one of the stable positions to close the circuit. A mounting plate fixed to the housing provides a heat sink to ensure prompt temperature response.

Abstract: A structure for mounting a motor protector substantially as a thermally responsive switch in an enclosed electric compressor including an electric motor and a compressing means provided in a closed housing. The structure includes a terminal support provided air-tightly through an upper wall of the compressor housing, a plurality of conductive pins for connecting an external power-supply circuit to the motor, the conductive pins projecting inside and outside the terminal support. One of the inner conductive pins is conductively connected to a terminal pin provided in the motor protector or to an equivalent thereof. Thus, the motor protector is disposed and held within the compressor housing so that heat is exchanged between the motor protector and a coolant gas. A motor winding is connected to the other terminals and the other conductive pins provided in the terminal support.

Abstract: The invention is directed to a fuse (1), in particular for electric motors (3), which includes a sensor (13) taking support upon the stator winding (14) of the electric motor (3), the sensor being made of a fusible material the melting of which on undue heating of the stator winding (14) causes opening of a switching device (18) connected in the supply circuit of the motor.

Abstract: A reversible connector for applying selectively different power levels to a three phase electrical motor. Lead wires from the motor are brought out to a terminal block having an array of female terminals arranged for mating engagement with arrays of pins on opposite sides of the reversible connector. The pin arrays are setwise interconnected so that engagement with the terminal block produces appropriate connections for the selected power level. Three phase power leads are connected to the connector, and the connector is engaged with the terminal block in that facing direction which is appropriate for the power level being applied to the power leads.

Abstract: An electromagnetic assembly including an electromagnetic coil wound on a core of ferromagnetically conductive material. A temperature protection circuit includes a fuse which breaks when the electromagnetic assembly becomes overheated. The fuse is thermally coupled to pole pieces of the assembly and is in electrical circuit with the coil.

Abstract: A hydraulic circuit branch of a cooling system in thermal contact with the stator winding of a hydraulic power generator is provided with a feed tube divided into two separate input tube sections. The downstream ends of the input tube sections are connected to respective multiplicities of subsidiary hydraulic circuit branches in the form of winding bars via a pair of semicircular manifolds. The current throughput through the winding bars is monitored by determining the difference between the rates of coolant flow through the approximately identical input tube sections. If the rates of coolant flow or throughputs in the input tube sections differ from one another by an amount which itself differs from a predetermined reference value by more than a preselected threshold, a warning signal is generated indicating that heat removal from the hydraulic power generator is being impaired.

Abstract: A device for mounting a thermal overload protector to the motor of a hermetic refrigeration compressor. The overload protector is temperature responsive and is operative to protectively interrupt the current to the motor when the stator windings, rotor, or other heat source in the compressor overheats due to a compressor overload. The protector's mounting device is a plastic receptacle having a shield connected by an integral hinge. The hinge not only facilitates manufacturing the receptacle as a unitary part by an injection molding process, but also enables the shield to be opened for inserting the overload protector into the receptacle. The overload protector is held firmly in place by a U-shaped bracket integrally disposed inside the receptacle. A U-shaped groove runs along the inner edge of the bracket and is designed to slidingly engage protectors of various shapes. The receptacle includes an opening on one side of the protector opposite the heat retaining shield.

Abstract: The invention set forth herein is a three phase current sensor for providing a signal indicative to the three phase current and phase imbalance. The sensor comprises an electrically insulated current carrying conductor for each phase with one end of the conductor forming a line side connection and the other end of the conductor forming a load side connection. Each conductor is substantially U-shaped in configuration having leg portions and a bight portion. The conductors are positioned proximate one another and have their bight portions overlapping forming a cylinder-like cup. The cup has a bottom portion and a wall portion, the bottom portion formed by the bight portions of the conductors and the wall portion formed by the leg portions of the conductors. The leg portions of each conductor is substantially parallel to the longitudinal axis of the cup and radially positioned approximately 60 from the leg portions of the other conductors forming the cup.

Abstract: A by-pass vacuum motor assembly wherein the motor cooling fan is positioned in an opening at the bottom of the motor band and immediately above a flat plate portion of the fan housing bracket. The flat plate portion functions as a plate diffuser, redirecting air drawn through the commutator end bracket and across the motor internals into a radial exhaust between a bottom portion of the band and a top portion of the fan end bracket. The invention also includes a brush holder clip passing through a vertical opening in the commutator end bracket and engaging a collar on the brush mechanism. The brush mechanism passes through a horizontal opening in the commutator end bracket which intersects with the vertical opening. Armature grounding is achieved by a disk maintained in a recess in the commutator end bracket and urged by a spring against the bearing receiving the motor shaft.

Abstract: Method of operating an electronically commutated motor, controlled by a board mounted electronic circuit, wherein current surges in such circuit are suppressed while dissipating heat associated with such suppression from motor structure as opposed to the control circuit. The heat associated with control circuit current surge suppression is dissipated into the bowels of the motor as opposed to being dissipated from a heat generating resistor mounted on the control circuit board as has been done heretofore. Illustrated structure includes current surge suppressing special winding turns on the motor core. Such special winding turns are connected with a known electronic control circuit so that power supplied to such circuit is transmitted through the special winding on the motor. Current surges associated with operation of the motor control circuit are then suppressed, during operation, by the special winding inside the motor.

Abstract: An engine starter has a plunger electromagnetically actuated by holding and attracting coils to move a pinion toward a ring gear on the engine and also to move a first movable contact on the plunger towards first and second stationary contacts to be electrically connected together by the first movable contact to electrically energize a starter motor. A relay is provided and has normally open contacts electrically connected in series to a power source and the connection between the holding and attracting coils. The relay coil is connected in series to a starter switch and a temperature sensor. The temperature sensor is formed by a normally closed switch having a third stationary contact connected to the relay coil, and a bimetallic element carrying a second movable contact grounded through the bimetallic element.

Abstract: A thermally released switching mechanism which in a simple fashion and at a precisely defined switching point clearly interrupts the current to the motor when a preset, highest admissible temperature is exceeded, at least until the actual temperature has once against fallen below the highest admissible temperature. The thermally released switching mechanism is comprised of a lever element made of a memory element which, upon exceeding the highest permissible temperature set value, lifts the brush from a commutator or a slipring. This mechanism preferrably employs a memory element with a two-way effect. This thermal switching mechanism is suitable both for commutator motors with hammer or tubular brush holder systems as well as for slipring motors.

Abstract: Motor stator comprises a stator core having coil windings thereon which are connected to lead wires. A motor protector is connected to at least one of the windings and to one lead wire. The electrical connections between the lead wires, the windings and the protector are made by means of a stator connector mounted on the stator core and which has a pocket which receives the protector. Adjacent to the pocket, a cavity is provided which receives a terminal which connects one of the windings to a first terminal extending from the protector. The windings extend to terminals in the connector which have terminal tabs. The tabs are matable with receptacles in a complementary connector which can be coupled to the stator connector. The second protector terminal extends into the connector housing and is received in a terminal therein which also has a tab for mating with a receptacle in the complementary connector.

Abstract: Described is a control circuit or energizing circuit for a series field mr. To limit the surge of inrush startup current to no greater than the steady-state running current, a series string of three thermistors is inserted in series with the motor. The thermisters have negative temperature coefficient, and have nominally equal ratings and values. The circuit has application in motor/blower systems.