A magnetic coupling, includes a driving rotor sleeved on the driving shaft, a driven rotor sleeved on the driven shaft, external magnets mounted on the driving rotor and internal magnets mounted on the driven rotor and located on the inner sides of the external magnets; a plurality of internal magnets are arranged and uniformly distributed along the circumferential direction of the driven rotor; the external magnets and the internal magnets are aligned one by one along a radial direction; the internal magnets and the external magnets are magnetized along the radial direction; adjacent internal magnets have opposite magnetizing directions, and adjacent external magnets have opposite magnetizing directions; magnetic poles of the internal magnets are opposite to magnetic poles of the corresponding external magnets, and the driving rotor and the driven rotor form a working magnetic circuit through a magnetic field generated by the external magnets and a magnetic field generated by the internal magnets, wherein at least the external magnets are magnet exciting coils that generate a working magnetic field through power supply.

A winding type permanent magnet coupling transmission device includes a permanent magnet rotor and a winding rotor that is coaxial with the permanent magnet rotor and capable of rotating relative to the permanent magnet rotor. An air gap exists between the permanent magnet rotor and the winding rotor. The winding rotor is connected to a control structure capable of regulating the current/voltage of the winding rotor. The control structure is capable of controlling the current or voltage of the winding rotor, so as to regulate the output torque of the transmission device, with no need to configure any corresponding mechanical execution mechanism. Therefore, the transmission device has a simple structure and small energy loss.

A winding type permanent magnet coupling transmission device includes a permanent magnet rotor and a winding rotor that is coaxial with the permanent magnet rotor and capable of rotating relative to the permanent magnet rotor. An air gap exists between the permanent magnet rotor and the winding rotor. The winding rotor is connected to a control structure capable of regulating the current/voltage of the winding rotor. The control structure is capable of controlling the current or voltage of the winding rotor, so as to regulate the output torque of the transmission device, with no need to configure any corresponding mechanical execution mechanism. Therefore, the transmission device has a simple structure and small energy loss.

An example electromagnetic actuator includes a drive shaft, a motor operable to rotate the drive shaft, and a load shaft coupled to an armature body. A clutch is operable to control whether the drive shaft engages the load shaft. A rotatable portion of the clutch corotates with the drive shaft and includes a field winding and a clutch body. A stationary portion of the clutch includes an exciter winding that is inductively coupled to the rotatable portion and is operable to energize the field winding. The field winding is operable, when energized, to provide a magnetic field that causes engagement or disengagement between the clutch body and an armature body. A method of operating an electromagnetic actuator is also disclosed.

An example electromagnetic clutch assembly includes a rotatable portion and a stationary portion. The rotatable portion includes a field winding and a clutch body, and the stationary portion includes an exciter winding that is inductively coupled to the rotatable portion and is operable to energize the field winding. The field winding is operable, when energized, to provide a magnetic field that causes engagement or disengagement between the clutch body and an armature body. A method of operating an electromagnetic clutch assembly is also disclosed.

An example electromagnetic clutch assembly includes a rotatable portion and a stationary portion. The rotatable portion includes a field winding and a clutch body, and the stationary portion includes an exciter winding that is inductively coupled to the rotatable portion and is operable to energize the field winding. The field winding is operable, when energized, to provide a magnetic field that causes engagement or disengagement between the clutch body and an armature body. A method of operating an electromagnetic clutch assembly is also disclosed.

An inner brake motor includes a stator assembly, a rotor assembly connected to the stator assembly, and a magnetic brake assembly connected to the rotor assembly. The rotor assembly has a rotor cover sleeved on the periphery of the stator assembly. The magnetic brake assembly has a movable piece selectively attached to or detached from the rotor assembly. A convex-concave brake structure is formed between the movable piece and the rotor cover. The magnetic brake assembly brakes by frictionally engaging with the rotor assembly through the brake structure, thereby achieving the effect of simplifying the brake structure and reducing the volume of the inner brake motor.

An inner brake motor includes a stator assembly, a rotor assembly connected to the stator assembly, and a magnetic brake assembly connected to the rotor assembly. The rotor assembly has a rotor cover sleeved on the periphery of the stator assembly. The magnetic brake assembly has a movable piece selectively attached to or detached from the rotor assembly. A convex-concave brake structure is formed between the movable piece and the rotor cover. The magnetic brake assembly brakes by frictionally engaging with the rotor assembly through the brake structure, thereby achieving the effect of simplifying the brake structure and reducing the volume of the inner brake motor.

The present invention relates to a power transmission apparatus using a magnetic field, the power transmission apparatus comprising a rotor module, a front driver module and a rear driver module, or comprising a rotor module and any one of a front driver module and a rear driver module. The power transmission apparatus generates, using power received from a power applying driving body or power received from a power receiving driving body, rotational power from a combination of an induced magnetic field which the front driver module generates, a rotating magnetic field which the rotor module generates, and a rotating magnetic field which the rotor module generates together with the front driver module and the rear driver module, and acceleratedly rotates to increase the rotational power, thereby transmitting power to the power receiving driving body and to a target object.

A power tool is provided having a motor and a motor shaft, wherein a fan wheel in the power tool is designed to generate an air flow for cooling the motor. The power tool provides a coupling formed magnetically between the fan wheel and the motor shaft such that the motor shaft drives the fan wheel in a rotary movement with a speed that is less than a speed of the motor shaft. As a result of the magnetic coupling of the fan wheel and motor shaft, the movements of the two components can be decoupled from one another such that an increase in the rotational speed of the motor shaft does not also result in an increased speed at the fan wheel. As a result, fan losses can be considerably reduced and the efficiency of the motor of the power tool can be significantly improved. A method is also provided for cooling a motor of a power tool, wherein there is a magnetic coupling between a fan wheel and a motor shaft of the power tool.