Power tools with conductive couplings used with active injury mitigation technology are disclosed. Conductive couplings are particularly relevant to table saws, hand-held circular saws, track saws, miter saws, and band saws with active injury mitigation technology. Conductive couplings provide a mechanism through which an electrical signal can be coupled or imparted to a blade, and then monitored for changes indicative of human contact with the blade. An exemplary conductive coupling includes a brush that establishes an electrical connection with a moving part of a power tool, and the brush maintains contact with the moving part of the power tool during at least 40 hours of cumulative time when the motor is spinning the arbor and blade without an interruption in the electrical connection sufficient to trigger the reaction system. A conductive coupling may be two-sided compliant. A conductive coupling may connect to a motor shaft to minimize electrical noise.

The invention relates to a carbon brush and a method for producing a carbon brush for electrically contacting a contact structure, in particular a commutator or a collector ring of an electric machine, moved with respect to the carbon brush, a brush body of the carbon brush being obtained by pressing and heat-treating a material blend, the material blend being obtained by blending a graphite powder with a resin and an additive, the resin being pyrolyzed by means of heat treatment after pressing, wherein graphene is used as the additive at a portion of 0.01 to <5% by weight of the material blend.

The invention relates to a carbon brush and a method for producing a carbon brush for electrically contacting a contact structure, in particular a commutator or a collector ring of an electric machine, moved with respect to the carbon brush, a brush body of the carbon brush being obtained by pressing and heat-treating a material blend, the material blend being obtained by blending a graphite powder with a resin and an additive, the resin being pyrolyzed by means of heat treatment after pressing, wherein graphene is used as the additive at a portion of 0.01 to <5% by weight of the material blend.

A slip ring assembly including a plurality conducting disks spaced-apart and stacked mounted along a common rotation axis, each being electrically connectable and fixedly securable to a generator mounted in a rotatable nacelle of a wind turbine so that a rotation of the rotatable nacelle triggers a rotation of the conducting discs; and a plurality of slip ring devices, each being electrically connectable and mechanically securable to a fixed electrical distribution conductor mounted to a fixed pole so as to have a fixed position relative to the fixed pole, and each of the plurality of the slip ring devices having upper and conducting fingers arranged so as to rotatably receive a respective conducting disk therebetween and to provide an electrical connection between the conducting disks and the slip ring device during rotation of the nacelle.

A slip ring assembly including a plurality conducting disks spaced-apart and stacked mounted along a common rotation axis, each being electrically connectable and fixedly securable to a generator mounted in a rotatable nacelle of a wind turbine so that a rotation of the rotatable nacelle triggers a rotation of the conducting discs; and a plurality of slip ring devices, each being electrically connectable and mechanically securable to a fixed electrical distribution conductor mounted to a fixed pole so as to have a fixed position relative to the fixed pole, and each of the plurality of the slip ring devices having upper and conducting fingers arranged so as to rotatably receive a respective conducting disk therebetween and to provide an electrical connection between the conducting disks and the slip ring device during rotation of the nacelle.

A rotor is provided with: a rotor core which rotates integrally with a shaft and has a plurality of radially extending teeth; windings including coil portions wound around the teeth; a commutator that is attached to the rotor core and integrally rotates with the shaft, the commutator including metal commutator segments having contact portions with which precious metal brushes make sliding contact, and a plurality of terminals to which the windings are bonded; elements which include capacitors and respectively electrically connecting terminals to which both ends of the coil portions of the same phase are connected; and a coating layer formed of an oil applied to the contact portions. A motor includes this rotor.

A carbonaceous material is fabricated by kneading of carbon powder and a binder. The carbonaceous material is granulated such that an average particle diameter of the carbonaceous material is 0.3 mm or more. A brush material is fabricated by mixing of the granulated carbonaceous material and metallic powder. A ratio of the metallic powder to a total weight of the brush material is adjusted to 1% by weight or more and 30% by weight or less. Pressure molding is performed on the fabricated brush material, and thermal processing is further performed on the brush material at a temperature at which a resin in the brush material is not carbonized.

A carbonaceous material is fabricated by kneading of carbon powder and a binder. The carbonaceous material is granulated such that an average particle diameter of the carbonaceous material is 0.3 mm or more. A brush material is fabricated by mixing of the granulated carbonaceous material and metallic powder. A ratio of the metallic powder to a total weight of the brush material is adjusted to 1% by weight or more and 30% by weight or less. Pressure molding is performed on the fabricated brush material, and thermal processing is further performed on the brush material at a temperature at which a resin in the brush material is not carbonized.

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.

The invention relates to a carbon brush and a method for producing a carbon brush for electrically contacting a contact structure, in particular a commutator or a collector ring of an electric machine, moved with respect to the carbon brush, a brush body of the carbon brush being realized by pressing and hardening a material blend, the material blend being obtained by blending a graphite powder with a hardenable resin and an additive, wherein graphene is used as the additive.