JPS59162754A - Brushless self-excited single-phase synchronous generator - Google Patents

Abstract

PURPOSE:To improve the initial voltage rising characteristic and to improve the generating eficiency of a synchronous generator by annularly forming a rotor to surround a stator, thereby obtaining a large remaining magnetic flux. CONSTITUTION:A housing 1 of a generator is composed by securing a cover 3 to a cylinder integral with a crankcase 2 of an engine. A rotor 6 is annularly formed, and the rotor 6 is secured by a threaded member 21 to an annular unit 17 of a coupling member 14. Field windings 24, 25 are respectively wound on a pair of arcuate units 22, 23 of the rotor 6. A stator 8 is secured to a shaft 7 which is projected to the cover 3 oppositely to the end of a crankshaft 4. The outer surface of the stator 8 is opposed to the inner surface of the rotor 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that a capacitor excitation winding connected to a phase advance capacitor to form a closed circuit and a load winding to which a load is connected are connected to a stator as an unbalanced two-phase winding. The purpose of the brushless self-excited single-phase synchronous generator is to To provide a brushless self-excited single-phase synchronous generator that improves voltage rise characteristics, improves power generation efficiency, and obtains a relatively large inertial mass so that a flywheel of an engine can be omitted.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. First, in FIGS. 1 and 2, the housing 1 of this generator has a cover 3 fixed to a cylindrical portion 2α that is integral with the crankcase 2 of the engine. It consists of On one side of the housing 1, an engine crankshaft 4 whose end extends into the housing 1 is supported via a bearing 5, and a rotor 6 is connected to the end of the crankshaft 4. on the other hand,
A support shaft 7 is protruded from the cover 3 so as to face the end of the crankshaft 4, and a stator 8 is fixedly supported on the support shaft 7.

The end of the crankshaft 4 is formed into a tapered conical shape, and this conical portion 9 has a conical hole 1 corresponding to the conical portion 9.
0 and a flange 11 at one end is a member 12
is inserted. A male threaded portion 13 is provided protruding from the tip of the conical portion 9, and this male threaded portion 13 is inserted into the central hole 15 of the connecting member 14.

The connecting member 14 includes a disk portion 16 in which a central hole 15 is bored, and an annular portion 17 formed in an annular shape and having an inner diameter larger than that of the disk portion 16, which are equally spaced in the circumferential direction. The supporting portion 18 connects the disk portion 16 and the annular portion 17 at a plurality of positions (four in this embodiment). Each support portion 18 is formed in a curved manner so as to expand outward in the radial direction toward the cup <-3 side of the housing 1. Such a connecting member 14 is integrally connected to the crankshaft 4 by screwing and tightening a nut 19 onto the male threaded portion 13 inserted through the central hole 15. In addition, the connecting member 14 is provided with a cooling fan 20 extending radially outward from the disk portion 16 between the respective support portions 18, and this cooling fan 20 prevents overheating within the housing 1.

The rotor 6 is basically formed in a cylindrical shape, and is fixed to the annular portion 17 of the connecting member 14 by a screw member 21. The rotor 6 is therefore substantially integrated with the crankshaft 4. The rotor 6 is provided with a pair of arcuate portions 22.23, which are thinned by a portion having a central angle α, at symmetrical positions with respect to its axis, and these arcuate portions 22.23 are provided with field windings. The wires 24, 25 are each wrapped in a ring. Each field winding 24, 25 is connected to a diode 26, 27 as a rectifier to form a closed circuit.

A small diameter portion 28 is provided at the tip of the support shaft 7, and the cylindrical stator 8 is fitted into the small diameter portion 28. A screw hole 29 is concentrically drilled at the tip of the small diameter portion 28, and a washer 3 that abuts one end of the stator 8 is inserted into the screw hole 29.
A bolt 31 is screwed through the bolt 31. Thereby, the stator 8 is held between the washer 30 and the stepped portion 32 of the support shaft 70 created by providing the small diameter portion 28, and is fixed to the support shaft 7. In this fixed state, the stator 8 is arranged such that its outer surface faces the inner surface of the rotor 6.

Referring also to FIG. 3, the stator 8 includes a capacitor excitation winding 34 that is connected to a phase advance capacitor 33 to form a closed circuit, and a capacitor excitation winding 34 that is provided on the cover 3 or connected to a receptacle 35 to form a closed circuit. The load winding 36 constituting the circuit is wound as an unbalanced two-phase winding so as to have a phase difference of 90 degrees in electrical angle. A lead wire (not shown) for connecting to a load is also drawn out of the housing 1 from the safety safety 35 .

To explain the operation of this embodiment, when the rotor 6 rotates together with the crankshaft 4, the residual magnetic flux of the rotor 6 causes a phase-advanced current to flow through the condenser excitation winding 34, and a positive current having a magnetizing effect corresponds to it. Phase rotating magnetic field and field winding 2
A reverse phase fractional switching magnetic field interlinking with 4 and 25 is generated. The reverse phase fractional magnetic field induces an alternating voltage in the field winding 24.25, and the field current is rectified by the diode 26.27 to become a direct current. Due to the combination of the self-excitation effect due to the field current and the self-excitation effect due to the magnetizing effect of the positive-phase rotating magnetic field, the phase-advanced current of the capacitor excitation winding 34 gradually increases,
Accordingly, the load winding 36 has a capacitor excitation winding 34.
A voltage having a phase difference is induced, and the voltage is applied from the receptacle 35 to the load via the lead wire.

As mentioned above, the rotor is formed into an annular shape surrounding the stator, so the length of the arc portion where the field winding is applied should be made relatively thick to lengthen the magnetic path. Therefore, it becomes possible to secure a large residual magnetic flux, and the initial voltage rise characteristics are improved. In addition, since the rotor rotates around the stator, the inertial mass of the rotating part can be reduced, making it possible to omit the engine's flywheel, which contributes to making the overall engine smaller and lighter. This also reduces costs. moreover,
Since the stator is located within the rotor, it is relatively small, thus reducing the overall length of the capacitor excitation winding and load winding, reducing copper losses and improving power generation efficiency.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a partially cutaway sectional view of the device of the present invention, and FIG.
A line cross-sectional view, FIG. 3 is a diagram showing a circuit configuration of an unbalanced two-phase winding.

Claims (1)

[Claims] The capacitor excitation winding, which is connected to the phase advancing capacitor to form a closed circuit, and the load winding, to which the load is connected, are connected to the stator as an unbalanced two-phase winding, and are connected to the engine crankshaft. In a brushless self-excited single-phase synchronous generator in which a rotor is provided with a field winding forming a closed circuit with a rectifier, the rotor is formed in an annular shape surrounding a stator,
A brushless self-excited single-phase synchronous generator, wherein the field winding is annularly wound around the arc portion of the rotor.