GB2086147A - Slip-ringless electric generator - Google Patents

Abstract

A slip-ringless inductor alternator flywheel generator comprises one or more stator segments (1) with armature windings (7), and a claw poleflux distributing rotor (2) on an internal combustion engine flywheel (4). At least one stationary excitation yoke (5) with an excitation winding (6) is segment-like and associated with the stator segment (1). The generator is suitable for motor vehicles having a confined installation space. <IMAGE>

Description

SPECIFICATION Slip-ringless electric generator The invention relates to slip-ringless generators.

Generators having fixed armatures and fixed field windings and magnetic flux conducting rotors are already known, although these generators are normally used as individual modules of, for example, a battery charger in a motor vehicle. On the other hand, flywheel generators are already known, that is to say, generators whose rotor is integrated with the flywheel of an internal combustion engine and whose stator is secured to, for example, the engine housing. These types of generators when designed with electrical excitation require a large amount of space, and servicing is necessary in the case of models having slip-rings. A new solution had to be sought for the purpose of reducing the spatial requirement of units, particularly in motor vehicles, and for reducing the essential maintenance work.

The present invention consists in a slip-ringless electric generator, having a stator carrying an armature winding, an electrically energised, stationary excitation part and a rotatable magnetic flux conducting rotor which is secured to a flywheel of a drive motor and which co-operates with the excitation part and with the stator.

This has the advantage that it takes up far less space, is maintenance-free and renders it possible to regulate the output by controlling the excitation current.

it is particularly advantageous if the stator and the excitation parts are split up into segments with respective armature and field windings. Various electrical circuits having different voltage requirements can be supplied. Appropriately correlated voltage regulators for the individual field windings are not subjected to mutual interference as a result of changes of load.

The invention is further described by way of example with reference to the drawings, in which Figs. 1 and 2 are respectively a diagrammatic elevation and a cross-section through a slipringless flywheel generator having a magnetic flux conducting rotor.

Referring to Figs. 1 and 2, a single-wire or multi-wire armature winding 7 is disposed in the slots of a stator segment 1. The stator segment is secured to a clutch housing (not illustrated) or an engine housing of an internal combustion engine for a motor vehicle. Furthermore, an excitation yoke 5 having an excitation winding 6 is disposed on the clutch housing or on the engine housing. It will be seen particularly in Fig. 1 that an excitation yoke 5 is located exactly opposite the stator segment 1. A magnetic flux conducting claw-pole rotor 2 is rotatably disposed between the stator segment 1 and the excitation yoke 5. The magnetically conducting rotor 12 is secured to the engine flywheel 4 which can also carry a starter ring gear 3.An air gap 8 on the stator side is located between the magnetically conducting rotor 2 and the stator 1, and an air gap 9 on the exciter side is located between the magnetically conducting rotor 2 and the excitation yoke 5.

Compared with the known electrically excited segment/flywheel generators having claw poles with an excitation part which extends around the entire periphery of the bore, the generator in accordance with the invention has just a segmental excitation yoke. The average turn length of the excitation winding on this excitation yoke is relatively very small, the average turn length being the average of the lengths of the individual turns of the excitation winding. The excitation winding 6 therefore requires only a small amount of expenditure on copper material.

In contrast to permanent magnet energised segment/flywheel generators which require expensive control electronics on the output side, or expensive mechanical variation of the magnetic circuit for regulation, it is possible to regulate the output voltage in a simple manner only at the exciter side in the arrangement in accordance with the invention.

Several circumferentially spaced stator segments 1 can be arranged about the rotor 2, the excitation yoke 5 being circumferentiaily extended to co-operate with all of the stator segments.

Alternatively, a separate excitation yoke 5 with its own excitation winding can be associated with each stator segment. In this latter case an individual voltage regulator can be associated with each excitation winding 6 by known circuitry.

Thus, voltage stages regulated independently of one another can be realised.

1. A slip-ringless electric generator having a stator carrying an armature winding, an electrically energised, stationary excitation part and a rotatable magnetic flux conducting rotor which is secured to a flywheel of a drive motor and which co-operates with the excitation part and with the stator.

2. A generator as claimed in claim 1, in which the stator comprises several stator segments and the excitation part is a segment-like yoke common to the stator segments.

3. A generator as claimed in claim 1, in which the stator comprises several stator segments carrying respective armature windings and the excitation part comprises separate excitation yokes each having an individual excitation winding and each associated with a respective segment of the stator.

4. A generator as claimed in claim 3, in which an individual voltage regulator is associated with

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Slip-ringless electric generator The invention relates to slip-ringless generators. Generators having fixed armatures and fixed field windings and magnetic flux conducting rotors are already known, although these generators are normally used as individual modules of, for example, a battery charger in a motor vehicle. On the other hand, flywheel generators are already known, that is to say, generators whose rotor is integrated with the flywheel of an internal combustion engine and whose stator is secured to, for example, the engine housing. These types of generators when designed with electrical excitation require a large amount of space, and servicing is necessary in the case of models having slip-rings. A new solution had to be sought for the purpose of reducing the spatial requirement of units, particularly in motor vehicles, and for reducing the essential maintenance work. The present invention consists in a slip-ringless electric generator, having a stator carrying an armature winding, an electrically energised, stationary excitation part and a rotatable magnetic flux conducting rotor which is secured to a flywheel of a drive motor and which co-operates with the excitation part and with the stator. This has the advantage that it takes up far less space, is maintenance-free and renders it possible to regulate the output by controlling the excitation current. it is particularly advantageous if the stator and the excitation parts are split up into segments with respective armature and field windings. Various electrical circuits having different voltage requirements can be supplied. Appropriately correlated voltage regulators for the individual field windings are not subjected to mutual interference as a result of changes of load. The invention is further described by way of example with reference to the drawings, in which Figs. 1 and 2 are respectively a diagrammatic elevation and a cross-section through a slipringless flywheel generator having a magnetic flux conducting rotor. Referring to Figs. 1 and 2, a single-wire or multi-wire armature winding 7 is disposed in the slots of a stator segment 1. The stator segment is secured to a clutch housing (not illustrated) or an engine housing of an internal combustion engine for a motor vehicle. Furthermore, an excitation yoke 5 having an excitation winding 6 is disposed on the clutch housing or on the engine housing. It will be seen particularly in Fig. 1 that an excitation yoke 5 is located exactly opposite the stator segment 1. A magnetic flux conducting claw-pole rotor 2 is rotatably disposed between the stator segment 1 and the excitation yoke 5. The magnetically conducting rotor 12 is secured to the engine flywheel 4 which can also carry a starter ring gear 3.An air gap 8 on the stator side is located between the magnetically conducting rotor 2 and the stator 1, and an air gap 9 on the exciter side is located between the magnetically conducting rotor 2 and the excitation yoke 5. Compared with the known electrically excited segment/flywheel generators having claw poles with an excitation part which extends around the entire periphery of the bore, the generator in accordance with the invention has just a segmental excitation yoke. The average turn length of the excitation winding on this excitation yoke is relatively very small, the average turn length being the average of the lengths of the individual turns of the excitation winding. The excitation winding 6 therefore requires only a small amount of expenditure on copper material. In contrast to permanent magnet energised segment/flywheel generators which require expensive control electronics on the output side, or expensive mechanical variation of the magnetic circuit for regulation, it is possible to regulate the output voltage in a simple manner only at the exciter side in the arrangement in accordance with the invention. Several circumferentially spaced stator segments 1 can be arranged about the rotor 2, the excitation yoke 5 being circumferentiaily extended to co-operate with all of the stator segments. Alternatively, a separate excitation yoke 5 with its own excitation winding can be associated with each stator segment. In this latter case an individual voltage regulator can be associated with each excitation winding 6 by known circuitry. Thus, voltage stages regulated independently of one another can be realised. CLAIMS

1. A slip-ringless electric generator having a stator carrying an armature winding, an electrically energised, stationary excitation part and a rotatable magnetic flux conducting rotor which is secured to a flywheel of a drive motor and which co-operates with the excitation part and with the stator.

2. A generator as claimed in claim 1, in which the stator comprises several stator segments and the excitation part is a segment-like yoke common to the stator segments.

3. A generator as claimed in claim 1, in which the stator comprises several stator segments carrying respective armature windings and the excitation part comprises separate excitation yokes each having an individual excitation winding and each associated with a respective segment of the stator.

4. A generator as claimed in claim 3, in which an individual voltage regulator is associated with each generator stator segment.

5. A slip-ringless electric generator constructed and adapted to operate substantially as herein described with reference to and as illustrated in the drawings.