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 wire brush for a slipring includes a contact section, from which a stabilizer arm is extending backwards towards the brush block of the slipring. The stabilizer arm holds a friction section, which is in friction contact with the contact section at a friction contact area. Such contact, in operation, generates internal friction within the brush when the brush is moved and, therefore, suppresses oscillations of the brush.

A driving device includes a motor and a control unit for controlling of the motor. The motor includes a motor body and an end cap assembly disposed at one end of the motor body. The motor body comprises a stator, a rotor rotatable relative to the stator, and a motor shaft fixed to and rotated with the rotor. The end cap assembly is provided with two brushes. The control unit includes two connectors for connecting with an external power source. The two brushes are respectively electrically connected to the connectors through the control unit. Lengths of connecting routes of the two brushes to the corresponding connectors are substantially equal to each other.

A motor includes a commutator having segments, and feeding brushes which successively come into sliding contact with the segments. One of the plurality of feeding brushes is a first feeding brush with an electric resistance value that varies in a rotation direction of the commutator. The rest of the feeding brushes are second feeding brushes with a constant electric resistance value in the rotation direction. The first feeding brush includes a high resistance portion disposed in a part including a forward end portion of the first feeding brush in the rotation direction, and a low resistance portion arranged side-by-side with the high resistance portion in the rotation direction. The electric resistance value of the second feeding brushes is higher than that of the low resistance portion.

A motor includes a commutator having segments, and feeding brushes which successively come into sliding contact with the segments. One of the plurality of feeding brushes is a first feeding brush with an electric resistance value that varies in a rotation direction of the commutator. The rest of the feeding brushes are second feeding brushes with a constant electric resistance value in the rotation direction. The first feeding brush includes a high resistance portion disposed in a part including a forward end portion of the first feeding brush in the rotation direction, and a low resistance portion arranged side-by-side with the high resistance portion in the rotation direction. The electric resistance value of the second feeding brushes is higher than that of the low resistance portion.

Provided is a structure for a slip ring and a brush of a WRSM capable of reducing an axial length of a motor by increasing a contact area between the slip ring and the brush and improving reliability for smoothly implementing performance of the motor by stably supporting a shaft of the motor, the structure including: an inner slip ring combined with a rotation shaft of a motor; a brush disposed at a circumference of the inner slip ring and having a plurality of wrinkles contacting an outer circumferential surface of the inner slip ring formed therein; an outer slip ring disposed at a circumference of the brush and making in contact with the plurality of wrinkles of the brush; and a holder that supports the outer slip ring.

Provided is a structure for a slip ring and a brush of a WRSM capable of reducing an axial length of a motor by increasing a contact area between the slip ring and the brush and improving reliability for smoothly implementing performance of the motor by stably supporting a shaft of the motor, the structure including: an inner slip ring combined with a rotation shaft of a motor; a brush disposed at a circumference of the inner slip ring and having a plurality of wrinkles contacting an outer circumferential surface of the inner slip ring formed therein; an outer slip ring disposed at a circumference of the brush and making in contact with the plurality of wrinkles of the brush; and a holder that supports the outer slip ring.

A slip ring assembly is used with a surgical shaft assembly. The slip ring assembly includes a slip ring, a first conductor mounted on the slip ring, a commutator rotatable relative to the slip ring, and a second conductor mounted on the commutator. The slip ring assembly further includes a flexible member disposed between the slip ring and the commutator. The flexible member comprises a body and flexible protrusions extending from the body, wherein the flexible protrusions are elastically deformed against the first slip ring.

A slip ring assembly is used with a surgical shaft assembly. The slip ring assembly includes a slip ring, a first conductor mounted on the slip ring, a commutator rotatable relative to the slip ring, and a second conductor mounted on the commutator. The slip ring assembly further includes a flexible member disposed between the slip ring and the commutator. The flexible member comprises a body and flexible protrusions extending from the body, wherein the flexible protrusions are elastically deformed against the first slip ring.

The present invention provides a stator including magnets having six poles; a rotor disposed inside the stator and including thirteen slots; a coil wound around the slot; a rotary shaft coupled to the rotor; a commutator coupled to the rotary shaft and connected to the coil; and a plurality of brushes disposed to be pressed against the commutator and located to have an angular interval of 63 to 66 in the circumferential direction of the rotary shaft, thereby providing advantageous effects in that a current ripple is minimized and a torque is maximized.