An a.c. generator for a vehicle includes: a rotor rotatably supported within a case; and a stator having a cylindrical stator core in which a plurality of slots are formed at given intervals circumferentially so as to open toward the inner peripheral side thereof and a stator winding constructed by connecting three single-phase windings wound on the stator core into Y connection, the stator being fitted onto the case so as to surround the rotor, wherein each of the single-phase windings comprises a first winding which is connected into the Y connection and a second winding which is connected in series to the first winding and has a given phase difference in electrical angle with respect to the first winding, and wherein a connecting portion of the first winding and the second winding constituting each of the single-phase windings is connected to a pair of three-phase diode bridges, and an end portion of the second winding constituting each of the single-phase windings is connected to another pair of three-phase diode bridges.
A generator in which connections among winding sets are changed to produce diverse powers different in voltage. Windings are grouped circumferentially in slots into winding sets, which are wound spaced circumferentially 120 electrical degrees apart to provide a three-phase system of windings. Any one winding set produces a low voltage applied to an automotive electrical system. A controller unit connects windings in other winding sets in series and/or in parallel thereby producing powers different in voltage. As an alternative, the stator is comprised of an inside cylinder forming one surface of an air gap, a circular toothed member having teeth arranged circumferentially on the inside cylinder to form sequential slots opened radially outwardly of the stator, and an outside cylinder prepared separately from the toothed member then fit over the toothed member.
A neutral point diode having three connecting terminals electrically commonly connected to each other is used in a type for connecting each generating coil of a three-phase alternating current electric generator for a vehicle in a Y-shape connection. The coil terminal of a neutral point side of each generating coil is connected to each of the three connecting terminals of this neutral point diode. A diode having two connecting terminals electrically commonly connected to each other is used in a type for connecting each generating coil in a .DELTA.-shape connection. The coil terminals of two adjacent generating coils are connected to the respective two connecting terminals of this diode. In both the types, one coil terminal is connected to one connecting terminal and a connecting work is simplified.
A capacitor-input type three-phase rectification circuit comprises a three-phase AC power supply (1), a diode rectifier circuit (4), and a low-frequency filter connected between the three-phase AC power supply (1) and the diode rectification circuitry (4), the low frequency filter consisting of AC reactors (2u)(2v)(2w) and .DELTA.-connection or Y-connection capacitors (8u)(8v)(8w), so that higher harmonic currents are reduced to be equal to or less than standard values, and that lowering in input power factor and lowering in DC voltage are prevented from occurrence.
There are proposed a manufacturing method of a winding assembly of a rotating electrical machine using a rotation block and a fixed block and a manufacturing apparatus used for the same. The rotation block includes a rotation surface rotatable around a rotation axis, and the fixed block includes a first surface and a second surface opposite to each other and a shaping surface. The shaping surface is formed between end parts of the first and the second surfaces, is made to have an almost semicircular shape with the rotation axis as the center, and extends along the rotation axis. Plural wire rods are simultaneously fed from the first surface of the fixed block to the rotation surface of the rotation block, and the wire rods positioned on the rotation surface are bent by rotation of the rotation block.
A stator includes a cylindrical stator core and a stator winding composed of a three-phase stator winding portion constructed by connecting three winding phase portions into a three-phase star connection, a neutral point of the stator winding being electrically connected to a rectifier for rectifying alternating-current output, wherein each of strands of wire constituting the three winding phase portions is led out from a coil end group of the stator winding to an outer side to constitute a neutral-point terminal, each of the neutral-point terminals has a flat side surface portion, and a neutral-point joint portion of aid stator winding is constructed by abutting and electrically joining the flat side portions of the neutral-point terminals.