Abstract: Disclosed is an improvement to the stability of D.C. motor brushes mounted in brush boxes with wings is improved by angling the wings toward the commutator such that the brush spring contacts the brush at one or more points intermediate the ends of the brush. Improved cooling is provided by utilizing an end plate with apertures and a brush plate which in combination with the commutator, provides a brush plate aperture for cooling air flow. In a preferred embodiment, speed variations of the motor can be achieved by selectively disconnecting one or more brushes in a four brush embodiment reducing the torque and rotating speed of the motor. In a preferred embodiment, the use of a diode to interconnect same polarity brushes permits a speed change to be accomplished by selectively connecting one or the other end of the diode.

Abstract: Disclosed is an improvement to the stability of D.C. motor brushes mounted in brush boxes with wings is improved by angling the wings toward the commutator such that the brush spring contacts the brush at one or more points intermediate the ends of the brush. Improved cooling is provided by utilizing an end plate with apertures and a brush plate which in combination with the commutator, provides a brush plate aperture for cooling air flow. In a preferred embodiment, speed variations of the motor can be achieved by selectively disconnecting one or more brushes in a four brush embodiment reducing the torque and rotating speed of the motor. In a preferred embodiment, the use of a diode to interconnect same polarity brushes permits a speed change to be accomplished by selectively connecting one or the other end of the diode.

Abstract: A separately excited DC motor system is arranged to provide operation in a smooth, continuous electrical retarding mode. A series contactor connects the motor armature to a DC power source and is controlled so as to immediately open upon sensing of a need for electrical braking. Concurrently, power to the motor field is reversed so that no additional changes are required to brake to zero speed. Field current is modulated to control armature current so as to control braking effort. When speed falls below a value necessary to maintain armature voltage above battery voltage, the armature is cyclically short-circuited to boost armature current so that when the short-circuit is removed, the armature reactance forces current to continue for regeneration.

Abstract: A system for driving a blower of a heating, ventilating, and/or air conditioning (HVAC) system. The blower discharges heated or cooled air to a space for conditioning the air in the space by changing its temperature. A motor drives the blower at a speed or torque defined by a motor control signal thereby to control air flow rate of the HVAC system. The system includes a temperature sensor generating a temperature signal representative of the temperature of the air discharged to the space by the blower. In response to the temperature signal, a control circuit generates the motor control signal to cause the motor to operate at a minimum speed or torque until the temperature of the discharged air as represented by the temperature signal reaches a reference temperature.

Abstract: A system which drives a component of a heating, ventilating, and/or air conditioning (HVAC) system in response to a system control signal such as a temperature signal provided by a thermostat. The system includes a motor having a stationary assembly and a rotatable assembly. The rotatable assembly is in magnetic coupling relation to the stationary assembly and is in driving relation to the component. The motor drives the component in response to a control signal generated by a microprocessor. The microprocessor is responsive to parameters representative of the system and to the system control signal. The parameters are stored in a memory and are defined in response to a parameter select signal. The control signal provided by the microprocessor controls the speed and torque of the motor. The system further includes an instruction memory for storing instructions controlling the operation of the microprocessor.

Abstract: A skew angle setting tool and method for assisting in orienting the skew pin of an apparatus having a mandrel for stacking rotor laminations for dynamoelectric machines is described. The skew pin is movable to have at least one predetermined angular orientation with respect to the axis of the mandrel. The tool includes a first member configured to be positioned in a generally coextensive relation with the mandrel and has at least one location thereon corresponding to a preselected rotor lamination stack height, and a second member disposed in predetermined relation to the location on the first member corresponding to the preselected rotor lamination stack height. The skew pin is positionable in registration with one or more locations on the second member to orient the skew pin in corresponding angular orientations with respect to the mandrel axis.

Abstract: A condition-responsive electric switch mechanism having a snap-acting bistable spring switch element carrying a movable contact, and an actuator movable in response to a detected condition to operate the bistable spring switch element. The spring switch element is capable of snapping between a circuit open position in which the movable contact is spaced from a fixed contact and a circuit closed position in which the movable contact engages the fixed contact. The spring switch element has a head mounting the movable contact thereon, and a pair of arms extending outwardly from the head being formed free of connection to one another at their distal ends opposite the head. The arms are fixed to a first terminal blade at their distal ends in a configuration deflected from the relaxed position so as to stress the switch element making it capable of snapping between the circuit open and circuit closed positions for a wide variety of preset contact gaps.

Abstract: A method and apparatus for preventing overspeed of an electrically powered golf car having a shunt wound direct current electric motor with an armature winding and a field winding serially connected to respective switching devices and to a source of on-board direct current electric power. The golf car includes a control adapted and connected to regulate the current in each of the armature and field windings for controlling speed in response to an operator's command. The golf car incorporates overspeed detection by sensing the magnitude of current in each of the armature winding and the field winding and detecting when the current in the armature winding reverses direction. The magnitude of the armature winding current upon such reversal is compared to a preselected value and an overspeed signal generated when the reverse current magnitude exceeds the preselected value.

Abstract: A permanent magnet rotor for an electronically commutated motor (ECM) has a core, a plurality of magnetizable elements spaced around the core, and a thin-walled retaining shell which has been stretched around the core and magnetizable elements to hold the elements in position. The rotor is made by an inventive method which involves axially aligning the core and surrounding magnetizable elements with the retaining shell, and cold-pressing the retaining shell over the core and elements to sandwich the elements between the shell and core. The core and magnetizable elements serve as a mandrel about which the shell is reformed in a cold working operation. Other aspects of the invention include the fixturing apparatus used to align the core and magnetizable elements with the retaining shell, and apparatus which is used to evenly space the magnetizable elements around the core and hold the elements in position during at least a portion of the cold-pressing operation.

Abstract: A system and methods to provide a desired operating area for a motor driving a fan for inducing a draft in a vent of a heating, ventilating and air conditioning system. The motor includes a stationary assembly and a rotatable assembly. The stationary assembly includes windings adapted to be energized in at least one preselected sequence. The rotatable assembly is in magnetic coupling relation to the stationary assembly and in driving relation to the fan. The system includes a commutating circuit responsive to a pressure signal representative of a minimum air pressure in the vent and a tachometer signal representative of the speed of the motor for controlling power switching devices. The power switching devices selectively connect a power supply to the windings to provide a motor current to the windings in the preselected sequence to produce an electromagnetic field for rotating the rotatable assembly at a motor operating speed.

Abstract: A pressure sensitive control device having a housing made up of a plurality of housing members, a diaphragm, a bistable snap-disc, a switch and an actuator. The snap-disc moves from one configuration to another upon application of pressure over a predetermined amount to drive the actuator which moves the switch from its normal operating position, which can be either closed or open, to a tripped position, which is opposite its normal operating position. Two adjacent housing members, which support the snap-disc and switch, respectively, are formed with cooperating spacers which allow the spacing of these housing members to be continuously varied over a small range of adjustment to allow the switch point of the control device to be adjusted after partial assembly of the control device. The diaphragm and some of the housing members may be subassembled for testing the components of the control device prior to complete assembly.

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: The present invention relates to an assembly for protecting motor leads extending between an electric motor shell and an external control unit or power source. The present invention in one form includes a fitting configured for insertion into a notch formed in a motor shell and for coupling to a plastic conduit or sheath which protects the motor leads. The fitting includes a boss and a notch interfitting portion. An opening formed in the boss and interfitting portion is sized to have motor leads extend therethrough. A groove formed in the interfitting portion is sized to have inserted therein the walls forming the notch in the motor shell. The outer diameter of the fitting boss is sized to be inserted into a flexible plastic conduit. Protuberances, such as partial threads, on the exterior surface of the boss provide that when the boss in inserted into the flexible conduit, the boss is not easily separated from the conduit, even at elevated operating temperatures.

Abstract: A protective DC link circuit connecting a motor to a power supply. The motor has a stationary assembly and a rotatable assembly in magnetic coupling relation thereto and includes windings adapted to be commutated in at least one preselected sequence. The motor also has power switches for selectively providing power to the windings in the preselected sequence by switching the power supply in connection with the windings whereby an electromagnetic field is produced for rotating the rotatable assembly. The DC link circuit connects the power supply to the power switches. The DC link circuit includes a link capacitor connected in parallel with the power supply wherein a voltage across the link capacitor defines a DC link voltage.

Abstract: A system which drives a compressor of a refrigeration system. The system includes a motor having a stationary assembly and a rotatable assembly. The stationary assembly includes windings adapted to be energized 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 system further includes a circuit for sensing a back electromotive force (EMF) voltage in the windings and for generating a BEMF signal representative thereof. The BEMF signal has first and second polarities representative of position of the rotatable assembly relative to a zero crossing of the sensed back EMF voltage. The first polarity is representative of the position of the rotatable assembly past a position corresponding to the zero crossing and the second polarity is opposite the first polarity.

Abstract: A contactor control system for a DC electric power system for reducing contactor tip contamination from dry-switching includes a first switch connected in circuit between a power source and a controller for enabling the controller upon closure of the first switch. A PTC resistor is connected between the first switch and a filter capacitor whereby charging current is supplied to the capacitor upon closure of the first switch. A solid-state switch is connected in series circuit with an electromagnetic actuator of a contactor having power contact tips in circuit between the power source and a load. The series combination of the actuator and solid-state switch is connected in parallel circuit with the filter capacitor.

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 system which drives a compressor of a refrigeration system at one or more 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 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 system which drives an indoor blower of a heating, ventilating, and/or air conditioning (HVAC) system in response to a system control signal. The system control signal has a BLOWER DEMAND state and a BLOWER END DEMAND state. The system comprises a motor having a stationary assembly and a rotatable assembly. The rotatable assembly is in magnetic coupling relation to the stationary assembly and in driving relation to the indoor blower. The system controls in response to the system control signal the rate of air flow of the HVAC system. The system operates at a first air flow rate in response to the BLOWER DEMAND state of the system control signal and operates at a second air flow rate greater than the first air flow rate when the BLOWER DEMAND state has been present for a first period of time. Alternately, the motor operates at a third air flow rate less than the first air flow rate for a second period of time in response to the BLOWER END DEMAND state of the system control signal.

Abstract: An electrical contact comprises a body formed of a precious metal in which the precious metal defines a contact surface of the body. At least one projection of the precious metal is formed generally centrally of the contact surface so as to extend therebeyond by successive discrete extrusions of the precious metal into a preselected configuration comprising the projection. A free end portion on the projection is spaced from the contact surface and comprises a chordal section of a sphere.