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.

A DC motor is provided that can suppress a commutator from wearing. A DC motor including a commutator formed of copper or a copper alloy of 99% or more copper, and a brush pressed against and in contact with the commutator, wherein the brush is composed of a sintered compact including graphite and copper powder, hard compound particles higher in hardness than any of the copper or the copper alloy and the graphite or the copper powder are contained in at least one of the commutator and the brush and are scattered on or near a contact surface of the commutator with the brush at least during use.

The invention relates to a discharge device (10) for discharging electric currents from a rotor part of a machine, in particular a rotor part realized with a shaft, into a stator part of the machine, the discharge device comprising a contact element (12), a support (13) and a spring mechanism (14), the support being connectable to a stator part in an electrically conductive manner, the contact element being predominantly made of carbon, the contact element being accommodated on the support in an axially movable manner and being connected to it in an electrically conductive manner, a contact force being applicable to the contact element by means of the spring mechanism so as to establish an electrically conductive sliding contact (17) between a sliding contact surface (15) of the contact element, said sliding contact surface serving to establish the sliding contact, and an axial shaft contact surface (16) of the shaft, wherein the contact element is disk-shaped, the sliding contact surface being at least annular and disposable coaxially relative to the shaft contact surface.

The invention relates to a discharge device (10) for discharging electric currents from a rotor part of a machine, in particular a rotor part realized with a shaft, into a stator part of the machine, the discharge device comprising a contact element (12), a support (13) and a spring mechanism (14), the support being connectable to a stator part in an electrically conductive manner, the contact element being predominantly made of carbon, the contact element being accommodated on the support in an axially movable manner and being connected to it in an electrically conductive manner, a contact force being applicable to the contact element by means of the spring mechanism so as to establish an electrically conductive sliding contact (17) between a sliding contact surface (15) of the contact element, said sliding contact surface serving to establish the sliding contact, and an axial shaft contact surface (16) of the shaft, wherein the contact element is disk-shaped, the sliding contact surface being at least annular and disposable coaxially relative to the shaft contact surface.

The present disclosure relates to a conductive slip ring for logging while drilling (LWD) instrument. The present disclosure utilizes a mechanical conductive slip ring to solve the problems of transmission of electric power and signals between two structures that have relative rotation, and the conductive slip ring has a simple structure, doesn't involve any complex circuit, and has low cost and high reliability. With the conductive slip ring in the present disclosure, there is no power transmission efficiency problem or signal transmission error rate problem. The conductive slip ring has high temperature-resistant, pressure-proof, and vibration-roof abilities, and can be applied widely.

The present disclosure relates to a conductive slip ring for logging while drilling (LWD) instrument. The present disclosure utilizes a mechanical conductive slip ring to solve the problems of transmission of electric power and signals between two structures that have relative rotation, and the conductive slip ring has a simple structure, doesn't involve any complex circuit, and has low cost and high reliability. With the conductive slip ring in the present disclosure, there is no power transmission efficiency problem or signal transmission error rate problem. The conductive slip ring has high temperature-resistant, pressure-proof, and vibration-roof abilities, and can be applied widely.

A method for manufacture of a gold-plated slipring contact, comprising steps of galvanic deposition of a copper layer on the electrically-conductive substrate; of a nickel and/or nickel phosphor layer on the copper layer; and of a gold layer on the nickel and/or nickel phosphor layer. While galvanically applying the copper layer on the substrate, the used galvanic bath explicitly does not include at least one of 3-carboxy-1-(phenylmethyl)pyridinium chloride sodium salt, cationic polymers with urea groups, 1-(3-sulfopropyl)pyridinium betaine, 1-(2-hydroxy-3-sulfopropyl)-pyridinium betaine, propargyl(3-sulfopropyl)ether sodium salt, sodium saccharin, sodium allylsulfonate, N,N-dimethyl-N-(3-cocoamidopropyl)-N-(2-hydroxy-3-sulfopropyl)ammonium betaine, polyamines, 1H-imidazole-polymer with (chloromethyl)oxiran, 3-carboxy-1-(phenylmethyl)pyridinium chloride sodium salt, 1-benzyl-3-sodium carboxy-pyridinium chloride, arsenic trioxide, potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tellerite, potassium seleno cyanate, alkali antimonyl tartrate, sodium selenite, thallium sulfate, and carbon disulfide, to create the outer surface of the contact that is at least an order of magnitude rougher than a surface of a conventionally-fabricated contact.

A method for manufacture of a gold-plated slipring contact, comprising steps of galvanic deposition of a copper layer on the electrically-conductive substrate; of a nickel and/or nickel phosphor layer on the copper layer; and of a gold layer on the nickel and/or nickel phosphor layer. While galvanically applying the copper layer on the substrate, the used galvanic bath explicitly does not include at least one of 3-carboxy-1-(phenylmethyl)pyridinium chloride sodium salt, cationic polymers with urea groups, 1-(3-sulfopropyl)pyridinium betaine, 1-(2-hydroxy-3-sulfopropyl)-pyridinium betaine, propargyl(3-sulfopropyl)ether sodium salt, sodium saccharin, sodium allylsulfonate, N,N-dimethyl-N-(3-cocoamidopropyl)-N-(2-hydroxy-3-sulfopropyl)ammonium betaine, polyamines, 1H-imidazole-polymer with (chloromethyl)oxiran, 3-carboxy-1-(phenylmethyl)pyridinium chloride sodium salt, 1-benzyl-3-sodium carboxy-pyridinium chloride, arsenic trioxide, potassium antimony tartrate, potassium tellurate, alkali arsenite, potassium tellerite, potassium seleno cyanate, alkali antimonyl tartrate, sodium selenite, thallium sulfate, and carbon disulfide, to create the outer surface of the contact that is at least an order of magnitude rougher than a surface of a conventionally-fabricated contact.

A device {i.e., a slip-ring or a homopolar motor/generator) (40, 50, 80) is adapted to provide electrical contact between a stator and a rotor (41, 83), and includes: a current-carrying brush-spring (31, 84) mounted on the stator, and having two opposite surfaces; a fibrous brush assembly (35, 69) mounted on the conductor, the brush assembly having a bundle of fibers (36, 71) arranged such that the tips of the fibers will engage the rotor for transferring electrical current between the stator and rotor; a ribbon (33, 85) of superconducting material mounted on each opposite surface of the current-carrying brush-spring and communicating with the stator and the brush assembly; and another ribbon (29, 86) of superconducting material mounted on the rotor. The device is submerged in a cryogenic fluid at a temperature below the transition temperatures of the superconducting materials such that the electrical resistivity of the device will be reduced and the current-transfer capability of the device will be increased.

A device {i.e., a slip-ring or a homopolar motor/generator) (40, 50, 80) is adapted to provide electrical contact between a stator and a rotor (41, 83), and includes: a current-carrying brush-spring (31, 84) mounted on the stator, and having two opposite surfaces; a fibrous brush assembly (35, 69) mounted on the conductor, the brush assembly having a bundle of fibers (36, 71) arranged such that the tips of the fibers will engage the rotor for transferring electrical current between the stator and rotor; a ribbon (33, 85) of superconducting material mounted on each opposite surface of the current-carrying brush-spring and communicating with the stator and the brush assembly; and another ribbon (29, 86) of superconducting material mounted on the rotor. The device is submerged in a cryogenic fluid at a temperature below the transition temperatures of the superconducting materials such that the electrical resistivity of the device will be reduced and the current-transfer capability of the device will be increased.