Abstract: A microcontroller with external memory interacts with a host computer or terminal via a fully isolated RS232 serial interface. An eight-bit D/A converter transforms signals generated digitally in the microcontroller. The low level analog signal at the D/A output is further amplified in a power amplifier which supplies a signal to the motor terminals of the motor to be programmed via solid state relays. The solid state relays form an array of switches which are selectively closed by a low level digit signal generated by the microcontroller and processed by digital circuits. Four signals may be modulated with a signal representing the line frequency and are used specifically in an emulation mode. The interface receives multi-function feedback signals (RPM) from the motor such as speed, memory, content, and diagnostic information. Comparators provide an integrity check of the connections (cable) and the input section of the motor (optocouplers).

Abstract: A method for assembling a condition-responsive electric switch mechanism having a snap-acting bistable spring switch element. The switch mechanism is assembled substantially in its entirety except for the capillary tube. The switch mechanism is then calibrated without the capillary tube using air pressure. Following calibration, the capillary tube is sealingly connected to the bellows, the capillary tube and bellows are filled with the operating fluid, typically a refrigerant, and the capillary tube is sealed to capture the operating fluid within the bellows and capillary tube.

Abstract: A reversible switched reluctance motor and methods therefor. The motor includes a current sensor for sensing the current supplied by a DC link and for producing a current signal having a parameter representative of the current. A controller provides a control signal having a parameter representative of the desired speed and direction of rotation of a rotatable assembly of the motor. A dwell generator provides firing pulses to a converter for driving the motor and varies the duration of each of the firing pulses as a function of the speed and direction parameter and the current parameter. Further, a timing generator, responsive to the speed and direction parameter, generates a timing signal defining a rate dependent on the parameter. The dwell generator varies the pulse rate of the firing pulses as a function of the defined rate of the timing signal and the converter commutates each of the windings for a period of time and at a rate dependent on the duration and pulse rate of the firing pulses.

Abstract: A two compartment motor has a frame, a pair of end shields disposed adjacent opposing ends of the frame to define a first compartment, a stator winding supported by the frame within the first compartment, an armature rotatably supported by the end shields and disposed within the first compartment adjacent the stator winding, a cover mounted to the motor adjacent one of the end shields to define a second compartment between the cover and the end shield, and a control plate mounted within the second compartment. The control plate serves as a mounting surface for securing a plurality of electrical components used in the control and operation of the motor in position within the second compartment. The control plate is a molded plastic component having integrally formed mounting mechanisms for at least one of the electrical components. The electrical components may include a starting capacitor, voltage and/or speed control switches, an overload device and electrical terminals.

Abstract: A system which drives a compressor of a refrigeration system at one or more preset speeds. The system includes a motor having a stationary assembly and a rotatable assembly. The stationary assembly includes windings adapted to be commutated in at least one preselected sequence. The rotatable assembly is in magnetic coupling relation to the stationary assembly and in driving relation to the compressor. The motor drives the compressor at a desired speed corresponding to a speed select signal representative of one of the preset speeds. The system further includes an application specific integrated circuit (ASIC) connected to the motor. The ASIC receives the speed select signal and is responsive to it for generating a commutation reference signal. The commutation reference signal in combination with the commutation signal generates a peak current demand signal and thereby cause the motor to operate at the desired speed.

Abstract: A control circuit for a motor driving a fan for inducing a draft in the exhaust of a heating, ventilating and air conditioning (HVAC) system. The control circuit may be used in conjunction with either a variable pressure sensor or one or two discrete pressure sensors. A controller receives information defining the pressure set point. The information may be from a switched register or low or high pressure input signals. The motor speed/torque is increased until the pressure set point is reached.

Abstract: An electric motor assembly has a motor housing, a stator mounted in the housing, a rotor rotatably mounted in the housing and disposed adjacent the stator, a pair of end shields mounted adjacent opposing ends of the motor housing having bearings disposed therein for rotatably supporting the rotor, a mounting bracket disposed in the housing, and a motor control component mounted in the bracket. The bracket has a one-piece, resilient body that is elastically deformable from a relaxed position to an expanded position, an engaging structure mounted on opposing portions of the body to secure the motor control component to the body, and a mounting structure that mounts the body in the housing. The bracket is mounted in the housing so that a surface thereof is disposed adjacent and interacts with an inner surface of the housing to prevent deformation of the bracket, thereby locking the component to the bracket.

Abstract: A system for conditioning air in a space by heating or cooling the air to change its temperature. A thermostat located within the space generates a two state temperature signal having a cyclic parameter which corresponds to the temperature of the air in the space as it rises and falls. A compressor supplies refrigerant to a heat exchanger by means of which changes are made in the temperature of the air. A variable speed motor drives the compressor in response to a motor control signal. A controller responds to the temperature signal and senses the cyclic parameter of the temperature signal. The controller generates the motor control signal as a function of the sensed cyclic parameter whereby the motor control signal is provided to the motor to control the torque or speed of the motor.

Abstract: A covered conduit box includes a cover which maintains screws, used to fix the cover to a base member of the box, captive, when the cover is disengaged. The cover includes stepped screw bores therein which allow the screws to cock slightly relative to the cover, to engage in mating channels provided in flanges on the base member, the flanges being angled away from the cover to provide a torque upon the screws, maintaining engagement between the cover and the body. The stepped screw bore maintains the screw captured within the bore unless pressure is applied against the end of the screw to cause a thread thereof to interact with sidewalls of the bore, at which point the screw can be disengaged from capture therein.

Abstract: A motor assembly has a lead guard detachably disposed within a housing adjacent a conductor receiving opening formed therein. The lead guard defines a space within the motor housing into which a conductor may be routed. The guard has a generally flat portion and an upstanding portion connected at an angle thereto that extends around three of four perimetral edges of the flat portion. A mounting mechanism is provided to position the lead guard within the housing of the motor. A guide mechanism for guiding conductors fed through the conductor receiving opening into the space defined by the lead guard may also be provided. This guide mechanism may be attached to or integrally molded with the generally flat portion of the lead guard and may include an angled/ramped portion, the edge of which abuts the inner surface of the housing below the conductor receiving opening to prevent conductors from entering the motor housing and coming in contact with rotating components disposed therein.

Abstract: A method of operating a brushless motor having a stationary assembly with at least two different energizable windings for producing spaced apart magnetic fields in time sequence, and a rotor adapted to rotate in response to the magnetic fields. The method includes the steps of simulating rotor position in accordance with the back emf condition of at least one winding, energizing a selected one of the windings in accordance with the simulated rotor position, sensing an underspeed condition when the motor speed is less than a minimum value for a length of time, and preventing energization of any of the windings when the motor speed is less than the minimum value for the length of time. An electrically commutated motor controller apparatus controls and speed of a variable speed motor compressor driven by an electrically commutated motor. A controller circuit includes a circuit for producing feedback signals representative of a back emf of the motor.

Abstract: A terminal board assembly for a dynamoelectric machine, adapted for supporting an overload device, comprises a body and an overload device support integral with the body and extending therefrom for cradling the overload device when the overload device is supported on the terminal board assembly. The body and the overload device support each include apparatus releasably secured in engagement with the overload device for retaining the overload device against displacement from the overload device support.

Abstract: An improved cooling arrangement for a dynamoelectric machine of the type having a plurality of stacked laminations forming a stator core. The stacked laminations have a central bore for passage of a rotor therethrough and a plurality of uniformly spaced winding slots extending radially outward from the bore and terminating at an end at least partially through the laminations. Adjacent ones of the slots define pole pieces extending from the bore into a radially outer portion of the laminations. The improvement comprises a plurality of cooling air passages extending axially through the stacked laminations generally parallel to the central bore with each of the air passages being positioned adjacent the terminating end of a corresponding one of the winding slots. Each air passage has a radially outer shape corresponding generally to a radially outer shape of the winding slots and preferably have a crescent shape when viewed axially.

Abstract: An operator sequentially inserts into an automated system for making armatures for electrodynamic machines loaded magazines containing a required number of hairpin conductors for an armature to be made, an armature core comprising a plurality of substantially aligned laminations preassembled to form the core and a commutator, and removes armatures completed by assembling these components. All the insertion and removal steps are performed from an operator's position such that operation of the system embodying the present invention is easily and conveniently performed even though the components and completed armatures can be of substantial weight. The use of a hairpin magazine, including the hairpin conductors required for an armature, permits simultaneous transfer of all the hairpin conductors into upper twist tooling wherein upper ends of the hairpin conductors adjacent end turn portions of the conductors are moved apart relative to one another.

Abstract: A structured product family of dynamoelectric machines for use in a plurality of applications has a frame with a closed end, and a set of permanent magnets is adhesively secured within the frame. An armature disposed in the frame for interaction with the permanent magnets includes a shaft, a core having a set of winding receiving slots therein, and a commutator. During manufacturing and assembly, stress on the motor shaft and commutator is minimized. A brush plate is associated with the frame for locating a set of brushes relative to the commutator, and an end shield is secured to the frame opposite its closed end. At least one freely aligning bearing assembly disposed in the end shield for freely aligning the shaft and including a bearing and a retainer having predetermined conditions preset with the retainer being adhesively secured to the end shield. A bracket is adhesively secured to the frame for connecting the dynamoelectric machine in anyone of the applications; and a novel brush assembly is provided.

Abstract: A permanent magnet rotor includes a rotor core having an axis of rotation and longitudinally extending radially projecting ribs. A plurality of arcuate magnetic elements are retained against an outer surface of the rotor by a cylindrical shell such that each magnet is disposed between a pair of the ribs. A hardenable adhesive is interposed between the outer surface of the core and the magnets and cooperates with the ribs and magnets to prevent rotational slippage of the magnets relative to the core during rotation of the rotor. Various embodiments utilize different techniques for retaining the components in assembled relation.

Abstract: A permanent magnet rotor includes a core and a plurality of magnetizable elements adhesively secured to the outer surface of the core. The core and adhered magnetizable elements are cold-pressed into a deep drawn cup-shaped outer metallic shell having a substantially closed end wall and an opposite open end defined by a peripheral edge which is rolled over the periphery of an end plate to encapsulate the core and magnetizable elements within the shell with an insulator disk disposed between each end of the core and the adjacent shell end wall and end plate. A method and apparatus for cold pressing the core and magnetizable elements into the cup-shaped shell and forming the peripheral edge of the shell over the end plate to effect encapsulation are also disclosed.

Abstract: A motor assembly has a stator and rotor housed within a frame. An end shield is attached to one end of the frame for rotatably supporting a shaft extending therethrough. A fan is mounted to the shaft adjacent the end shield. A fan cover is mounted to the end shield and about the fan in a snap-fit manner. The end shield includes a front face and an annular side face, and has a plurality of slots formed in the annular face. The end shield also includes a boss adjacent each slot, which is formed to include at least one bearing surface and a ramp thereon. The fan cover includes a plurality of mounting brackets spaced about its inner periphery and extending outwardly toward the end shield. Each mounting bracket has a projection thereon, which is receivable within the slot on the annular face of the end shield. Each bracket also includes a backstop with a crushable rib thereon.

Abstract: A dynamo-electric machine includes a stator core fixed in a casing and formed of stator lamination plates, and a rotor supported in a bore of the stator core and formed of a stack of rotor lamination plates. Each stator lamination plate has a tooth portion extending radially outward from the bore to an intermediate circumference, and a yoke portion defined between the intermediate circumference and the outer periphery of the stator lamination plate. Each of the rotor lamination plates has a number of equally circumferentially spaced closed slots, wherein each slot is defined by a curvilinear edge at an upper slot region adjacent the periphery of the plate. The curvilinear edge together with a pair of spaced parallel sides together define a top part of each slot, the top part opening into a bottom part of the slot which is substantially triangularly-shaped.

Abstract: A control system and method for an electronically commutated motor having a stationary assembly with a plurality of winding stages for carrying a motor current in response to application of a voltage having a magnitude subject to variations, the motor further having a rotatable assembly. The control system is adapted to receive control pulses having a duty cycle which is a function of a desired operating torque or speed for the motor. The control system and method are responsive to the motor current for generating a pluse width modulated (PWM) series of pulses having a pulse repetition rate having a duty cycle which is a function of the duty cycle of the control pulses. The PWM series of pulses are supplied to the commutating circuit as a pulsed signal whereby the operating torque or speed of the motor is a function of the duty cycle of the control pulses and is substantially independent of variations in the magnitude of the applied voltage.