A coil with a distributed winding formed from hairpins that each have two straight-line conductor portions arranged in different slots of a coil body. Contact regions shaped in circumferential direction adjoin the conductor portions at one axial end and are connected at the other axial end through a turning region. The contact regions have at the end remote of the coil body a connection portion that are aligned in radially extending rows. The contact regions of a layer are shaped in the same circumferential direction. A portion of the contact regions of an outer layer is deformed in radial direction to form an additional, and these contact regions are shaped in a circumferential direction opposite to the contact regions of the outer layer.

A widening apparatus for a hairpin-type stator coil is provided to extend a distance between welding portions of hairpin-type stator coils inserted into slots of a stator core, and the widening apparatus includes, a coil support unit installed on a base frame, a tool driving unit installed on the base frame to be vertically movable below the coil support unit, and including a first gear operation part and a second gear operation part, a plurality of lower widening tools operably connected to the first gear operation part, and reciprocally movable along a layer direction of the stator coils, and a plurality of upper widening tools operably connected to the second gear operation part, and configured to be reciprocally movable above the plurality of lower widening tools.

An arm of a coil segment having an approximate U shape is placed in a slot of a stator core, and a portion protruding from the slot is bent in a circumferential direction. An arm is bent in a direction of an arrow A, and another arm positioned at an inner side in the radial direction in relation to this arm is bent in a direction of an arrow B. The arm positioned at the outer side has at least a part of a bending inner side surface of a bent portion hardened by pressurization.

First receiving recesses for receiving distal end portions of slot insertion portions of normal coil segments, and second receiving recesses for receiving distal end portions of long slot insertion portions of variant coil segments are formed at circumferential intervals on outer peripheral surface of an inner twisting jig corresponding to the innermost layer. In a state where the distal end portions of the long slot insertion portions before being twisted are inserted into the second receiving recesses, the first receiving recesses are at positions displaced in the circumferential direction with respect to the distal end portions to be housed therein. Primary twisting is performed by rotating the inner twisting jig in this state, and then the distal end portions of the normal coil segments are inserted into the first receiving recesses and the secondary twisting is performed with a rotational amount larger than that of the primary twisting.

According to one embodiment, in a method, while supporting as end of an extension part of a coil segment by a flange of a forming jig from the radially outside and pressing an inclined, surface toward the other end surface in an axial direction of the stator core by a pressing part of the forming jig, rotating the stator core in a circumferential direction relative to the forming jig, in order to bend the extension part in the circumferential direction of the stator core such that the inclined surface is positioned to be substantially parallel to the other end surface. Thereafter, joining the inclined surfaces adjacent to each other is the radial direction of the stator core.

Provided is a twisting device of a hair pin-type stator coil. The twisting device of a hair pin-type stator coil, which is to twist-form a plurality of hair pin-type stator coils inserted as a plurality of layers in a stator core, includes i) a base frame, ii) a coil fixing unit installed on the base frame through a plurality of support rods, iii) a twisting tool unit allowing a plurality of stator coils of two adjacent layers, among the plurality of layers, to be inserted thereinto, the two layers being rotated in different directions, and installed to be movable up and down in the base frame on a lower side of the coil fixing unit, iv) a tool driving unit installed on the base frame and operatively connected to the twisting tool unit.

The present invention relates to a device (100) and a method for widening ends of legs of hairpin conductors arranged in slots of a stator core, and to a device (200) and a method for twisting ends of legs of hairpin conductors arranged in slots of a stator core. The device (100) for widening comprises at least one finger (111), preferably a plurality of fingers (111), for radially moving the ends of legs of hairpin conductors-said at least one finger (111) is arranged moveably in a radial inward and in a radial outward direction. Said at least one finger (111) is arranged moveably in an axial upward and in an axial downward direction. Said at least one finger (111) comprises at least one radially extending arm (101) and a separation member (102) being arranged adjacent to an, preferably radially inner, end of the arm (101). Said separation member (102) is designed for being positioned between two ends (5a, 5b) of radially neighbouring legs of pairs (6, 6′) of hairpin conductors. Said finger (111) has a first, preferably radially inner, section (104) adjacent to the separation member (102). Said first section (104) has a first radial width (114) dimensioned to receive at least one pair (6) of ends of legs and is adapted for moving said pair (6) of end of legs when the finger (111) is radially moved. Said finger (111) has a second, preferably radially outer, section (105), which does not overlap with the first section (104). Said second section (105) has a second radial width (116). Said first radial width (114) is smaller than the second radial width (116), and wherein said second section (105) is dimensioned to receive at least one pair (6) of legs without moving, when the finger (111) is radially moved.

A production method for manufacturing a hairpin coil includes positioning a plurality of hairpin-like conductor elements on a coil support such that conductor end portions of conductor elements to be connected, which protrude from the coil support, are arranged adjacent to one another as conductor end portion pairs, securing the relative position of the conductor end portions of a conductor end portion pair, and simultaneously welding the respective conductor end portions of a plurality of conductor end portion pairs by friction welding, by a friction surface of a welding tool being simultaneously moved in a frictional manner along the plurality of conductor end portion pairs.

An apparatus for twisting welding portions of a segment type stator coils is provided. The welding portions are in a number of layers and inserted into slots of a stator core. The apparatus includes a frame, a number of twisting jigs, and a partition member detachably provided at one of a pair of neighboring twisting jigs, and blocking the coil receiving recesses facing each other of the twisting jigs forming the pair. Each of the twisting jigs is provided for each layer of the stator coils, along a radial direction of the stator core, forming coil receiving recesses along a circumferential direction facing another twisting jig forming a pair, installed on the frame to be rotatable in different directions depending on layers of the stator coils, and is generally ring-shaped.

An apparatus (200) for deforming conductors of at least one winding assembly (100), protruding from a side of a stator or of a rotor (114) of an electric machine. The at least one winding assembly (100) comprises a plurality of basic conductors (102) comprising at least one leg inserted into cavities (115) of stator or rotor (114), each having at least one respective free or terminal end (108, 110). The apparatus (200) comprises at least one twisting matrix (202, 203) adapted to rotate about an axis (X), comprising at least one gripping element (204) adapted to grip at least one free end (108, 110) and adapted to be moved in radial direction with respect to said axis (X). The apparatus comprises at least one guide (206, 207) adapted to guide the at least one gripping element (204) along the radial direction with respect to the axis (X); and a radial actuator (208), adapted to put in motion the at least one gripping element (204) along the radial direction with respect to the axis (X).