In a cross sectional plane perpendicular to a center axis line of an annular core, a connection projection and a connection recess have complementary configurations in which the connection projection and the connection recess are narrowed in width with distance from coupling surfaces, the connection projection and the connection recess respectively include a pair of friction surfaces and a pair of friction surfaces extending in a direction separate from the coupling surfaces, the friction surface of the connection projection is inclined relative to a virtual normal line perpendicular to a line connecting bottom portions of the pair of friction surfaces of the connection projection, and the friction surface of the connection recess is inclined relative to a virtual normal line perpendicular to a line connecting bottom portions of the pair of friction surfaces of the connection recess.

The present invention relates to an electric machine, in particular a brushless permanent magnet motor, comprising a stator which comprises a plurality of teeth having at least one needle-wound winding strand, the at least one winding strand having at least two windings on adjacent teeth which are arranged in series, the at least two windings each comprising at least one winding layer, a needle channel being provided which is formed between the at least two windings by a crossing portion of the at least two windings and is filled at least in part. The present invention further relates to a method for winding a coil of an electric machine.

A stator manufacturing apparatus includes: an insert piece having such a stepped structure that a width of the insert piece increases along a winding axis direction of a coil from a side to be fitted into the coil, fitted into the coil, configured to maintain an inside width of the coil; and an insert piece driving unit configured to move the insert piece along the winding axis direction of the coil.

A stator-core-side expansive additive layer and a coil-side expansive additive layer include foam materials foaming by heating. A foam material included in the stator-core-side expansive additive layer has such a foaming characteristic that an increase characteristic of a foaming rate along with a temperature rise is shifted to a cold side relative to the increase characteristic of a foam material included in the coil-side expansive additive layer.

A motor for a surgical instrument includes a rotor and a stator. The rotor includes a shaft and a magnet. The stator includes (i) a cavity in which the rotor is disposed, and (ii) a coil assembly. The coil assembly includes multiple phase sets. The phase sets include multiple sets of wires. Each of the phase sets includes multiple coils and corresponds to a respective one of the sets of wires. The coils in each of the phase sets are at respective positions about the rotor. One of the sets of wires includes at least three wires. The stator causes the rotor to axially rotate a surgical tool of the surgical instrument based on current received at the sets of wires.

A method of fabricating a dynamoelectric machine utilizing multi-turn coils includes manufacturing a multi-turn coil having turn and ground insulation and installation of the coil into the stator core of the machine. The loop regions of the coil have no ground insulation during installation and the ground insulation at the loop regions is completed after installation of the coil.

A motor for a surgical instrument includes a rotor and a stator. The rotor includes a shaft and a magnet. The stator includes (i) a cavity in which the rotor is disposed, and (ii) a coil assembly. The coil assembly includes multiple phase sets. The phase sets include multiple sets of wires. Each of the phase sets includes multiple coils and corresponds to a respective one of the sets of wires. The coils in each of the phase sets are at respective positions about the rotor. One of the sets of wires includes at least three wires. The stator causes the rotor to axially rotate a surgical tool of the surgical instrument based on current received at the sets of wires.

A coil for an electrical machine having a stator with salient poles is disclosed. The coil has first and second coil sides joined by a respective coil end at each end to define a space for accepting a salient pole. Each coil side has an inner side facing the space and an opposed outer side. The coil comprises a plurality of turns of a conductor arranged in layers of turns with a first layer disposed on the inner side of the first coil side and outer side of the second coil side and a second layer disposed on the inner side of the second coil side and outer side of the first coil side. Arrangement of layers of turns of the conductor provides a thermal conduction path for the conductor with reduced thermal impedance, which facilitates transfer of heat into the stator from portions of the conductor oriented away from the stator surface.

A rotating electrical machine includes a supporting member, a stator core, a winding set, a shaft, a rotor, a magnetic generator, and a magnetic detector. The stator core has a ring-shaped yoke held inside the supporting member and tooth portions projecting from the yoke in a radial inward direction of the yoke. The winding set is wound on the tooth portions. The shaft extends through the stator core and is rotatably supported by the supporting member. The rotor is located in the stator core and rotates with the shaft. The magnetic generator is located at an end of the shaft. The magnetic detector outputs a signal indicative of a change in magnetic flux density created by the magnetic generator. The number of the tooth portions for every magnetic pole pair in the rotor is even.

A stator winding includes forty-eight winding bodies 22 that are each produced by winding a jointless continuous conductor wire that is coated with insulation, and that are arranged at a pitch of one slot in a circumferential direction so as to be mounted into a first slot 13.sub.1, a second slot 13.sub.2, and a third slot 13.sub.3 that are circumferentially consecutive at an angular spacing of six slots. The winding bodies 22 are configured into a -shaped coil pattern that is formed by inserting the conductor wire 19 sequentially into the first slot 13.sub.1, the second slot 13.sub.2, the third slot 13.sub.3, and the second slot 13.sub.2, so as to alternate an axial direction of insertion into the first slot 13.sub.1, the second slot 13.sub.2, and the third slot 13.sub.3.