A method for making contact wires for sliprings comprising the steps of: coating and/or plating a wire with a first metal of the group of nickel, chrome or a combination thereof; coating and/or plating the wire with a second metal of the group of gold, silver, or a combination thereof; delivering laser radiation and generating an interference pattern of the laser radiation to the surface of the wire; heating the surface selectively as defined by the interference pattern, modifying of the crystal structure and/or providing protrusions and/or recesses due to melting and/or evaporation of the surface material.

The invention provides a wind turbine including a nacelle, a rotor having at least one blade attached to a hub, and an electrical supply structure for supplying electrical power from the nacelle to the rotor. The rotor is rotatably connected to the nacelle about an axis of rotation. The supply structure comprises a switch which has a connected mode in which the nacelle and the rotor are electrically connected, and a disconnected mode in which the nacelle and the rotor are electrically disconnected. Furthermore, the switch is adapted to change from the disconnected mode to the connected mode when the rotor does not rotate.

The invention provides a wind turbine including a nacelle, a rotor having at least one blade attached to a hub, and an electrical supply structure for supplying electrical power from the nacelle to the rotor. The rotor is rotatably connected to the nacelle about an axis of rotation. The supply structure comprises a switch which has a connected mode in which the nacelle and the rotor are electrically connected, and a disconnected mode in which the nacelle and the rotor are electrically disconnected. Furthermore, the switch is adapted to change from the disconnected mode to the connected mode when the rotor does not rotate.

A brush for an electric motor has a brush body having a front end surface configured to make sliding electrical contact with a commutator of the motor. First and second side surfaces are connected to the front end surface. The first side surface and the second side surface are positioned on opposite sides of the brush body in a rotational direction of the commutator. The front end surface has a first contact surface and a second contact surface that contact the commutator earlier than other regions of the front end surface, and are respectively positioned on diametrically opposed corners of the front end surface. In an initial state, the width of the contact area between the brush and the commutator is increased to extend the commutation time.

A brush for an electric motor has a brush body having a front end surface configured to make sliding electrical contact with a commutator of the motor. First and second side surfaces are connected to the front end surface. The first side surface and the second side surface are positioned on opposite sides of the brush body in a rotational direction of the commutator. The front end surface has a first contact surface and a second contact surface that contact the commutator earlier than other regions of the front end surface, and are respectively positioned on diametrically opposed corners of the front end surface. In an initial state, the width of the contact area between the brush and the commutator is increased to extend the commutation time.

There is provided a contact type power feeding apparatus in which, even if a brush Br disposed in a space between the axis body and the cylinder body that are disposed concentric with each other wears out as a result of sliding, contact can be surely secured between the brush and the axis body as well as the cylinder body, thereby efficiently causing electric current to flow between the two. A brush Br has first brush pieces each having an inner wall surface to make surface-contact with an outer peripheral surface of the axis body; and second brush pieces each having an outer wall surface to make a surface-contact with an inner peripheral surface of the cylinder body. The brush is constituted by alternately arranging, in the circumferential direction, the first brush pieces and the second brush pieces in a state of keeping them in surface-contact with each other. The side wall surfaces of the first brush pieces and the second brush pieces are respectively formed into a tapered shape which is inclined relative to the radial direction. Coil springs are disposed between the second brush pieces that are adjacent to each other, in order to give a biasing force in a direction to move the second brush pieces away from each other.

A power supply apparatus for a field winding motor. A brush is disposed is a holder. An armature is connected to the brush and disposed in the holder. A slip ring is electrically connected to or disconnected from the brush. A support spring surrounds the brush between the slip ring and the armature. A coil is disposed outside of the holder so as to overlap the support spring and the armature. A first power terminal is connected to the brush and supplies a first driving current. A second power terminal is connected to the coil and supplying a second driving current.

A power supply apparatus for a field winding motor. A brush is disposed is a holder. An armature is connected to the brush and disposed in the holder. A slip ring is electrically connected to or disconnected from the brush. A support spring surrounds the brush between the slip ring and the armature. A coil is disposed outside of the holder so as to overlap the support spring and the armature. A first power terminal is connected to the brush and supplies a first driving current. A second power terminal is connected to the coil and supplying a second driving current.

In order to effect a seal a porous material which comprises one side of two opposing surfaces is used to restrict and evenly distribute externally pressurized gas, liquid, steam, etc. between the two surfaces, exerting a force which is opposite the forces from pressure differences or springs trying to close the two faces together and so may create a non-contact seal that is more stable and reliable than hydrodynamic seals currently in use. A non-contact bearing is also disclosed having opposing surfaces with relative motion and one surface issuing higher than ambient pressure through a porous restriction, wherein the porous restriction is part of a monolithic porous body, or a porous layer, attached to lands containing a labyrinth, the porous restriction and lands configured to not distort more than 10% of a gap created from differential pressure between each side of the porous restriction.

A carbon brush for transferring high currents having a connective piece for connecting an electric conductor and a consumable contact piece having a contact surface formed for abutting against a commutator element. The connective piece has a silver content of approximately 5% by weight to approximately 39% by weight and the contact piece has a silver content of approximately 40% by weight to 100% by weight.