Abstract: An electric motor includes a stator and a rotor rotatable relative to the stator. The rotor includes an axial shaft, a disc projecting radially from the shaft, and a ring magnet affixed to the disc. The shaft and the disc are integrally formed as a unitary body.

Abstract: An electric motor includes a stator assembly and a rotor assembly. The rotor assembly includes a rotor shaft that is rotatable relative to the stator assembly about a rotation axis. The motor also includes an endshield, a bearing assembly rotatably supporting the rotor shaft on the endshield, a shaft ground assembly electrically coupled to the rotor shaft, and a bearing lockplate. The bearing lockplate is fixedly coupled to the endshield. The shaft ground assembly is supported by the bearing lockplate on the endshield.

Abstract: A method and apparatus serve to mount a calibrated encoder assembly to an electric motor so that a sensor output signal waveform produced by the calibrated encoder assembly is aligned with a back electromotive force (BEMF) waveform of the electric motor. The calibrated encoder assembly is fixed to an alignment plate, which is attached to the electric motor. The electric motor is rotated using a servo driven functional tester and the BEMF waveform of the electric motor is measured. The sensor output signal waveform is measured, and the alignment plate is adjusted relative to the electric motor to align the sensor output signal waveform to the BEMF waveform. The alignment plate is secured to the electric motor in the adjusted orientation.

Abstract: A static auto-tuning system and method for controlling operation of a motor in a system. A speed reference signal is generated resulting in a speed response of the motor. Closed-loop feedback magnifies the rotating friction effect to an observable level. Inertia and rotating friction coefficient values of the system are estimated based on the speed frequency response and a virtual damping coefficient. A fixed low frequency speed signal may result in a first frequency response function for determining virtual damping, and a variable frequency excitation signal may result in a second frequency response function for determining the inertia and rotating friction characteristics. Closed-loop gains are determined based on these characteristics. The excitation signal may be sampled and a peak value in each interval may be identified and stored to produce an envelope of peak values for determining the gain response. Operation of the motor is controlled using the determined gains.

Abstract: A rotor assembly for an electric machine includes a rotor core that is fabricated from a plurality of laminations stacked along a rotational axis of the electric machine. The rotor core has a plurality of arcuately arranged, axially extending magnet-receiving slots. The rotor core includes a plurality of magnets received in respective ones of the magnet-receiving slots. Each of the laminations includes opposed deflectable magnet-retaining prongs that extend into a corresponding one of the magnet-receiving slots. The magnet-retaining prongs are deflected by and engage the magnets to exert a reactive force against the magnets and hold them in place. Each of the laminations also includes respective support posts axially adjacent the magnet-retaining prongs. The support posts extend alongside and thereby limit the deflection of the magnet-retaining prongs when engaged with the corresponding one of the magnets.

Abstract: A rotor includes magnets and a core including arcuately arranged pole segments. Each pole segment includes first and second prongs that extend away from the rotor axis and are at least in part arcuately spaced apart to define a cutout therebetween. Each pair of arcuately adjacent pole segments defines therebetween a respective magnet-receiving slot, with the first prong of one of the pole segments and the second prong of the other of the pole segments defining the slot. The magnets are received in slots, such that each of the magnets is at least in part interposed between one of the pairs of adjacent pole segments. The magnets and the pole segments are dimensioned and configured so that at least one of the first and second prongs is deflected by the magnet received in the respective slot, such that the prongs cooperatively apply a clamping force on the magnet.

Abstract: A spacing-assured gas discharge tube assembly is installed on a printed circuit board, which may be part of a motor controller. The discharge tube assembly includes a tube body and an electrostatic spacing shield disposed at least partially around the tube body. The shield is configured to prevent close physical proximity of adjacent structures having electrostatic fields that may alter the breakdown voltage of the tube body.

Abstract: A motor assembly includes a motor, a controller controlling at least one aspect of operation of the motor, and a control housing defining a control chamber. The controller is in part received within the control chamber. The controller includes a main electronics board and a modular connector assembly. The modular connector assembly includes a secondary electronics board and a connector at least in part supporting the secondary electronics board. The connector includes an inner connector portion and an outer connector portion. The connector extends through the control housing such that the inner connector portion is disposed inside the control chamber and the outer connector portion is disposed outside the control chamber. The outer connector portion defines a first access portal facilitating access to a first component of the secondary electronics board.

Abstract: A conveyor assembly is provided for use with a mobile vehicle. The conveyor assembly includes a conveyor module. The conveyor module includes a first roller assembly. The first roller assembly includes a first rotatable roller body and a second rotatable roller body. The first and second roller bodies are interconnected to each other in such a manner as to share a first rotational axis yet be at least substantially rotationally independent of each other, such that each of the first and second roller bodies can rotate without causing or interfering with rotation of the other of the first and second roller bodies.

Abstract: A dual motor system includes a first motor providing a lower speed range and a second motor providing a higher speed range, wherein the motors are coaxially arranged and aligned on and drive a common shaft, and a motor control system controlling the speed of the first motor and engaging the second motor as needed. The first motor provides a lower two-thirds of a full speed range, and the second motor provides the upper one-third in the form of one or more discrete fixed speeds. The system may also include a flow control system for automatically controlling the speed of the motors for particular applications, such as flow control in a pool.

Abstract: A method and apparatus serve to mount a calibrated encoder assembly to an electric motor so that a sensor output signal waveform produced by the calibrated encoder assembly is aligned with a back electromotive force (BEMF) waveform of the electric motor. The calibrated encoder assembly is fixed to an alignment plate, which is attached to the electric motor. The electric motor is rotated using a servo driven functional tester and the BEMF waveform of the electric motor is measured. The sensor output signal waveform is measured, and the alignment plate is adjusted relative to the electric motor to align the sensor output signal waveform to the BEMF waveform. The alignment plate is secured to the electric motor in the adjusted orientation.

Abstract: A system for braking an electric motor. For each motor winding, a first switch is connected between the winding and electrical ground and in series with a resistor and is closeable to connect the winding to ground through the resistor, and a second switch is connected between the winding and ground and is closeable to bypass the resistor. A controller receives feedback regarding the speed and sends to the second switch a pulse width modulated signal which selectively opens and closes the second switch to connect and disconnect the resistor to achieve an optimal equivalent average stator resistance for the motor speed which results in a power transfer to the resistor and increases a braking torque as the motor slows. The pulse width modulated signal opens the second switch for a longer time when the motor speed is higher and for a shorter time when the motor speed is lower.

Abstract: A spacing-assured gas discharge tube assembly is installed on a printed circuit board, which may be part of a motor controller. The discharge tube assembly includes a tube body and an electrostatic spacing shield disposed at least partially around the tube body. The shield is configured to prevent close physical proximity of adjacent structures having electrostatic fields that may alter the breakdown voltage of the tube body.

Abstract: A conveyor assembly is provided for use with a mobile vehicle. The conveyor assembly includes a conveyor module. The conveyor module includes a first roller assembly. The first roller assembly includes a first rotatable roller body and a second rotatable roller body. The first and second roller bodies are interconnected to each other in such a manner as to share a first rotational axis yet be at least substantially rotationally independent of each other, such that each of the first and second roller bodies can rotate without causing or interfering with rotation of the other of the first and second roller bodies.

Abstract: An electric motor includes a controller. The controller includes a controller housing presenting a heat sink surface. The controller further includes a printed circuit board and a power module. The printed circuit board is at least substantially disposed within the housing. The power module thermally engages the heat sink surface and is mounted transverse to the printed circuit board.

Abstract: A rotor includes magnets and a core including arcuately arranged pole segments. Each pole segment includes first and second prongs that extend away from the rotor axis and are at least in part arcuately spaced apart to define a cutout therebetween. Each pair of arcuately adjacent pole segments defines therebetween a respective magnet-receiving slot, with the first prong of one of the pole segments and the second prong of the other of the pole segments defining the slot. The magnets are received in slots, such that each of the magnets is at least in part interposed between one of the pairs of adjacent pole segments. The magnets and the pole segments are dimensioned and configured so that at least one of the first and second prongs is deflected by the magnet received in the respective slot, such that the prongs cooperatively apply a clamping force on the magnet.

Abstract: A dual motor system includes a first motor providing a lower speed range and a second motor providing a higher speed range, wherein the motors are coaxially arranged and aligned on and drive a common shaft, and a motor control system controlling the speed of the first motor and engaging the second motor as needed. The first motor is a variable speed motor providing a lower two-thirds of a full speed range, and the second motor is an induction motor providing the upper one-third in the form of one or more discrete fixed speeds. The system may include a transformer including a first winding tap which provides a first higher speed, and a second winding tap which provides a second higher speed. The system may also include a flow control system for automatically controlling the speed of the motors for particular applications, such as flow control in a pool.

Abstract: A safety switching system and method for braking an electric motor in a mobile device. A multi-phase shorting system brakes the motor by diverting power from the motor windings. Multiple independent switching units each include a switch control unit controlling multiple normally-closed switches which, in response to a safety controller, close to connect a respective motor winding to electrical ground. An electromechanical brake system mechanically brakes the motor. An independent switching unit includes two normally-open switches which, in response to the safety controller, opens to activate an electromechanical brake. A feedback system communicates to the safety controller a switch failure of any of the switches either as a short circuit fault or an open circuit fault. The feedback system may include an analog and/or a digital feedback system. If a switch failure is detected, the safety controller may activate the multi-phase shorting system and the electromechanical brake system.