A rotor for rotary electrical machine. The rotor providing a shaft and magnets supported by the shaft. The rotor further provides a protecting sleeve, extending around an outer surface of the magnets and being made at least partially of PEEK or epoxy resin.

Stator assembly for rotary electrical machine including a stator provided with windings. The stator assembly further includes a protecting sleeve extending around an inner surface of the windings and being made of an amagnetic material.

A stator assembly for rotary electrical machine including a stator provided with windings. A sealing and cooling element is overmolded onto the stator.

Rotor for electric machines and methods for fabricating rotors for electric machines are provided. An exemplary method includes assembling a stack of laminations to form a rotor core having an external surface. The rotor core defines one to five layers of internal cavities and an interior permanent magnet is positioned in a selected internal cavity. The method also includes locating a non-magnetic structural element in the selected internal cavity. Further, the method includes applying a compressive force on the external surface of the rotor core with an annular sleeve.

An electric work machine (1) includes: a brushless motor having a stator disposed around a rotor (30); and an output part driven by the rotor. The rotor has a rotor core (31) and first and second magnetic-pole parts (34S, 34N) disposed around a circumferential direction of the rotor core. When the induced voltage of the brushless motor is given as Va, the power-supply voltage of the brushless motor is given as Vb, the rotational speed of the brushless motor is given as ω, a first induced voltage constant, which is expressed by Va/ω, is given as Ea [V/krpm], a pole-pairs count, which is the number of the first magnetic-pole parts or the second magnetic-pole parts, is given as Pi, and a second induced voltage constant, which is expressed as Ea/Pi, is given as Eb [V/krpm pole-pairs count], the motor satisfies the condition: Eb≤0.025×Vb.

An electric work machine (1) includes: a brushless motor having a stator disposed around a rotor (30); and an output part driven by the rotor. The rotor has a rotor core (31) and first and second magnetic-pole parts (34S, 34N) disposed around a circumferential direction of the rotor core. When the induced voltage of the brushless motor is given as Va, the power-supply voltage of the brushless motor is given as Vb, the rotational speed of the brushless motor is given as ω, a first induced voltage constant, which is expressed by Va/ω, is given as Ea [V/krpm], a pole-pairs count, which is the number of the first magnetic-pole parts or the second magnetic-pole parts, is given as Pi, and a second induced voltage constant, which is expressed as Ea/Pi, is given as Eb [V/krpm pole-pairs count], the motor satisfies the condition: Eb≤0.025×Vb.

A high-frequency rotating structure provided by the invention has an annular rotating element with a quincuncial outer periphery, a plurality of radially arranged accommodating grooves respectively disposed in an annular body of the rotating element, a plurality of hole-shaped magnetic barrier spaces respectively disposed in the annular body, and respectively communicated with one of two ends of each of the accommodating grooves, and a plurality of magnetic assemblies respectively embedded in each of the accommodating grooves. A shortest first distance A between a groove wall of each of the two ends of each of the accommodating grooves and an outer annular surface of the body, and a shortest second distance B between a hole wall of each of the magnetic barrier spaces and the outer annular surface of the body are defined by the following formula 1:

[00001]$\begin{array}{cc}\alpha =\frac{A}{B}\times 100\%,122\%\ge \alpha \ge 90\%.& \mathrm{formula}1\end{array}$

A high-frequency rotating structure provided by the invention has an annular rotating element with a quincuncial outer periphery, a plurality of radially arranged accommodating grooves respectively disposed in an annular body of the rotating element, a plurality of hole-shaped magnetic barrier spaces respectively disposed in the annular body, and respectively communicated with one of two ends of each of the accommodating grooves, and a plurality of magnetic assemblies respectively embedded in each of the accommodating grooves. A shortest first distance A between a groove wall of each of the two ends of each of the accommodating grooves and an outer annular surface of the body, and a shortest second distance B between a hole wall of each of the magnetic barrier spaces and the outer annular surface of the body are defined by the following formula 1:

[00001]$\begin{array}{cc}\alpha =\frac{A}{B}\times 100\%,122\%\ge \alpha \ge 90\%.& \mathrm{formula}1\end{array}$

One variation of a system for an electric motor includes a set of coil assemblies defining: an inner radial facet, an outer radial facet, a first axial facet, and a second axial facet opposite the first axial facet. Additionally, each coil assembly in the set of coil assemblies includes a receiving member arranged at the outer radial facet of the coil assembly. Furthermore, the system includes a rotor comprising a set of magnetic elements: encompassing the inner radial facet, the outer radial facet, the first axial facet, and the second axial facet of the set of coil assemblies; and defining a radial magnetic tunnel. The system also includes a housing: engaging the receiving member of each coil assembly, in the set of coil assemblies to couple the housing to the set of coil assemblies; and includes a shaft coupled to the set of magnetic elements.

An embodiment provides a stator comprising a stator core having a plurality of teeth and coils wound around the teeth, wherein the tooth includes a body around which the coil is wound and a shoe connected to the body, the shoe includes a plurality of grooves and a curvature center of the inner peripheral surface of the shoe is the same as the center of the stator core.