A dual motor actuator according to an embodiment includes a main motor actuator outputting torque to a main output shaft by including a main motor and a main reduction gear, an auxiliary motor actuator outputting torque to an auxiliary output shaft by including an auxiliary motor and an auxiliary reduction gear, and a clutch connecting the main output shaft and the auxiliary output shaft to each other, wherein the clutch includes a fixed clutch connected to the main output shaft and a movable clutch coupled to or released from the fixed clutch and connected to the auxiliary output shaft, and the dual motor actuator further includes an output unit connected to the movable clutch and transmitting an output from the main motor actuator or the auxiliary motor actuator.

A motor device includes motors, detector in the respective motors to detect motor rotational speeds, and an output controller configured or programmed to output a single output rotational speed based on the motor rotational speeds input from the detectors. The output controller multiplies at least one of the input motor rotational speeds by a coefficient derived based on target rotational speeds of the motors to calculate a conversion value, and determines the output rotational speed.

A motor device includes motors, detector in the respective motors to detect motor rotational speeds, and an output controller configured or programmed to output a single output rotational speed based on the motor rotational speeds input from the detectors. The output controller multiplies at least one of the input motor rotational speeds by a coefficient derived based on target rotational speeds of the motors to calculate a conversion value, and determines the output rotational speed.

A rear-wheel drive device 1 includes a first electric motor 102A and a second electric motor 102B, each of which includes an electric motor main body and a rotational-state-quantity detection device. The relative positions between the reference position MS1 of a stator 14A of the first electric motor 102A and the reference position RS1 of a resolver stator 93 of the first electric motor 102A and the relative positions between the reference position MS2 of a stator 14B of the second electric motor 102B and the reference position RS2 of a resolver stator 93 of the second electric motor 102B coincide with each other based on a rotational direction of the first electric motor 102A and the second electric motor 102B which is either the rotational direction during forward movement of a vehicle 3 or the rotational direction during backward movement.

A method of load characteristic identification and acceleration adjustment for a machine tool is provided. A first acceleration of a transmission system is set according to the weight of a workpiece, and the working platform and the workpiece are driven at the first acceleration. A first elastic deformation of the transmission system and an amount of first position error of the transmission system are calculated when transmission system is moved at the first acceleration. A dynamic error is calculated according to the first elastic deformation and the first position error. When the dynamic error is less than or greater than a target error, a second acceleration is set to the transmission system, and a second elastic deformation and a second position error are calculated when the transmission system moves at the second acceleration unit the dynamic error is converged to the target error.

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.

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.

A force control method and system for multi-motor synchronization is provided. The force control method includes: acquiring a total desired force of a plurality of motors; calculating the desired force of each of the plurality of motors according to a characteristic of each of the plurality of motors; setting an external feedback loop for controlling each of the plurality of motors to operate according to the desired force, and taking a synchronization error of each of the plurality of motors as a feedback item of the external feedback loop; and setting an internal feedback loop for controlling each of the plurality of motors to operate according to the desired force, and taking an output force error of each of the plurality of motors as a feedback item of the internal feedback loop. The force control method and system ensures multi-motor synchronization under the premise of accurate force control.

A force control method and system for multi-motor synchronization is provided. The force control method includes: acquiring a total desired force of a plurality of motors; calculating the desired force of each of the plurality of motors according to a characteristic of each of the plurality of motors; setting an external feedback loop for controlling each of the plurality of motors to operate according to the desired force, and taking a synchronization error of each of the plurality of motors as a feedback item of the external feedback loop; and setting an internal feedback loop for controlling each of the plurality of motors to operate according to the desired force, and taking an output force error of each of the plurality of motors as a feedback item of the internal feedback loop. The force control method and system ensures multi-motor synchronization under the premise of accurate force control.

A fan assembly comprising a plurality of nested components comprising a first stator; a first rotor that is radially spaced from the first stator, wherein the first rotor is magnetically driven by the first stator, the first rotor includes a second stator whereby the second stator rotates with the first rotor; a second rotor that is radially spaced from the second stator, wherein the second rotor is magnetically driven by the second stator; and, a fan blade drivenly connected to the second rotor.