US1993825A - Magneto-electric machine - Google Patents

Description

Filed D60. 14, 1932 3 Sheets-Sheet 2 March 12, 1935. J, IBOHLE r 5,,

MAGNETO-ELECTRIC MACHINE Filed Dec. 14, 1932 5 Sheets-Sheet 3 java-afar:

Patented Mar. 12, 1935 PATENT OFFICE MAGNETO-ELEOTRIC MACHINE Jakob Bohli and Gottlieb Steiner, Solothum, Switzerland Application December 14, 1932, Serial No. 647,206

3 Claims.

This invention relates to a magneto-electric machine designed especially for use in connection with internal combustion engines and having a stationary armature coil.

5 In machines of this kind as hitherto known the armature coil is arranged aside of the rotating member of the device; and the planes in which the windings of the coil are disposed are usually parallel to the axis of rotation. This results in an inconvenient assymmetrical arrangement of such devices, rendering the mounting of said device on the internal combustion engine very diflicult. On the other hand, the cross sectionals of iron of the magnetic circuit are considerably limited by the overall dimensions of the device.

The subject of the present invention is a magneto-electric machine, the disadvantages of which are overcome thereby that the axis of the stationary armature coil is provided in the axis of rotation, that the rotary permanent magnet is axially displaced with respect to the armature coil and that the flux is conducted through the coil core by means of magnetic bars which are parallel to the axis of rotation at the outside of the permanent magnet and set apart from each other by an angle corresponding to the pole pitch, these magnetic bars leading alternatively to the adjacent and remote ends of two star-shaped magnetic plates, which are set apart from each other by one pole pitch.

Fig. 1 is a vertical section through the magneto-electric machine with a rotating permanent magnet.

Fig. 2 is a horizontal section on line AA of Figure I viewed in direction of the arrow.

Fig. 3 is a plan view of the automatic spark advance device.

Fig. 4 is a perspective view partly in section of the constructional form shown in Figs. 1 to 3.

Fig. 5 is a vertical section through a magnetoelectric machine with a bell-shaped permanent magnet.

Fig. 6 is a plan view of the device as shown in Fig. 5.

In the constructional form shown in Figs. 1 and 2 a represents the bearing bracket of the device for the driving shaft b of the rotating permanent magnet c. The latter has for instance 6 arms; 50 two adjacent pole arms have opposite polarities. These polarities are indicated on said arms by the letters N, S. d is the armature coil comprising the primary winding e and the secondary winding f. The permanent magnet c is axially displaced with respect to this armature coil 1.

Germany December 19, 1931 The armature coil has a hollow laminated iron core g which is made of sheet iron wound up in spiral or consisting of layers of she t iron. The shaft it extends through this hollow coil core and is firmly fixed to the magnet wheel 0; on' the end 5 of this shaft the contact breaker i for the primary current and the distributor arm for the high-tension current are disposed. Conducting members I and m respectively, both in the form of a star, are mounted on the ends of the coil core g insulated suitably from the coil core, disposed at right angles to the axis of this coil core and displaced 'angularly by one pole pitch to one another. These conducting bars are laminated i. e. they consist of layers of sheet iron and have, in the present example of a magnetic rotor with 6 poles, three arms each. The ends of the three arms of the conducting member I abut upon the three laminated conducting bars n, o, p, which are parallel to the shaft 22 and cast integrally with the magneto-casing q which is made of insulting material or non-magnetic metal. By

casting the conducting bars into insulating material the conditions with respect to eddy-current losses are improved 1. e. they are smaller than they would be in metal; these conducting bars are equally spaced apart on the side of the hearing bracket a by means of a ring u of non-magnetic material which is cast into the insulating material also, in the case that the housing a is made of insulating material. This ring is U- shaped, the shorter limb v of which, remote from the flange of the bearingbracket a has equally spaced openings for guiding the conducting bars. The ring u is at the same time adapted to fix the magneto housing q to the bearing bracket a. In the case that the housing qis made of metal, the ring u is not required, and the housing q is directly fixed to the bearing support a. In the same way as for the conducting member I, the conducting member m of the same shape abuts upon three laminated conducting bars 1, s, t, arranged in parallel to the shaft b and cast into the magneto-housing q. The course of the flux is as follows: At the north poles N of the magnetic wheel 0 themagnetic flux enters for example into the conducting bars n, o, p, from there into the conducting member Z, through the coil core g into the conducting member m, into the three conducting bars 12, s, t, and from thence into the three south poles S of the magnetic rotor and back to the north pole N of thesame. After an angular displacement of the magnetic rotor by one pole pitch, in the present example by one xth of its circumference, the course of the flux tional form of Fig.- 1, particularly the arrangement of' the two conductingmembers m, Z, and

the conducting bars n, o, p, and r, s, t, respec tively, can be seen, the latter being parallel to the axis of rotation.

Fig. 3 is a plan view of the automatic spark advance consisting, as known, of two centrifugal pieces 1/ which are pivotally fixed to the magnetic rotor c. The ends of these centrifugal pieces engage the teeth of a bush 2' firmly fixed to the driving shaft. In proportion to the engine speed these weights tend to move outwards displacing the magnetic rotor and by means of the shaft h the contact breaker cam i and the high tension distributor k with respect to the driving shaft 1). Springs 1/ are provided to return the centrifugal pieces.

Another constructional form of the device is shown in the Figs. 5 and 6 of the drawings, in which case the permanent magnet is bell-shaped; the automatic spark advance is provided between the drive shaft and the rotating permanent magnet to the arms of which the drive shaft for the contact breaker and high tension distributor is fixed which are enclosed by a top cap; this drive shaft extends right through the hollow coil core. For the rest the arrangement corresponds to that of the preceding example.

In the examples of a permanent magnet with six arms as described above, three times the sectional area for conducting the fiuxthrough the conducting bars and the star shape conducting members is available, as compared with the usual arrangements of this kind. Moreover the concentric arrangement of all the main parts of the magneto allows a completely cylindrical shape of the apparatus, thus rendering the mounting into the internal combustion engine very satisfactory.

We wish it to be understood that we do not deside to be limited to the exact details of construction shown and described, for obvious modification will occur to a person skilled in the art.

What we claim is:

1. In a magneto-electric machine, in combination a rotating permanent magnet, a drive shaft for the latter, magnet arms equally spaced apart and integral with said permanent magnet, a flux conducting member, flux conducting arms equally spaced apart by an angle corresponding to twice the angular spacing of the magnet arms and integral with the conducting member, an armature coil axially displaced with respect to said permanent magnet, and the axis of winding of which is provided in the axis of rotation, a second flux conducting member, flux conducting bars arranged around the said permanent magnet, spaced apart by an angle which corresponds to the angular spacing of the magnet arms and one set of these conducting bars leading from said permanent magnet to the arms of one of the two flux conducting members which are displaced from one another in the direction of rotation as the angular spacing of the magnet arms, the second set of these conducting bars leading to the arms of the second fiux conducting member, a coil core, said flux conducting bars, said two flux conducting members and the coil core being in conducting connection with each other and 75- of fiux conducting bars through said armature coil, a bearing bracket for said drive shaft, a ring of non-magnetic metal, a magneto-housing, a top cap, said ring being adapted to provide an equal spacing'pf said flux conducting bars and adapted to fix said magneto housing to said bearing bracket.

2. In a magneto-electric machine, in combination a rotating permanent magnet, a drive shaft for the latter, magnet arms equally spaced apart and integral with said permanent magnet, a flux conducting member, flux conducting arms equally spaced apart by an angle corresponding to twice the angular spacing of the magnet arms and integral with the conducting member, an armature coil axially displaced with respect to said permanent magnet and the axis of winding of which is provided in the axis of rotation, a second flux conducting member, flux conducting bars arranged around said permanent magnet, spaced apartby an angle which corresponds to the angular spacing of the magnet arms and one set of these conducting bars leading from said permanent magnet to the arms of one of the two flux conducting members which are displaced from one another in the direction of rotation, as the angular spacing of the magnet arms, the second set of these conducting bars leading to the arms of the second flux conducting member, a coil core, said fiux conducting bars, said two flux conducting members and the coil core being in conducting connection with each other and, adapted to conduct the flux furnished by said permanent magnet and distributed to the two sets of flux conducting bars through said armature coil, 9. bearing bracket for said drive shaft, a ring of non-magnetic metal, a magneto housing proper made of non-magnetic material, a contact breaker, a high tension distributor, a top cap, said ring being firmly held in the material of said magneto-housing and being U-shaped in crosssection, having uneven lengths of limb, the shorter limb of which has equally spaced openings for guiding the flux conducting bars, which are firmly held in the material of said magneto-housing, whilst the longer limb of said ring is adapted to fix said magneto-housing proper to said bearing bracket, a drive shaft for said contact breaker and said high tension distributor being fixed to said permanent magnet and extending right through the hollow coil core and the flux conducting member, said top cap enclosing said contact breaker and said high tension distributor.

3. In a magneto-electric machine, in combination a rotating bell-shaped permanent magnet, a drive shaft for the latter, magnet arms equally spaced apart and integral with said permanent magnet, a flux conducting member, flux conducting arms equally spaced apart by an angle corresponding to twice the angular spacing of the magnet arms and integral with the conducting member, an armature coil axially displaced with respect to said permanent magnet and the axis of winding of which is provided in the axis of rotation, a second fiux conducting member, flux conducting bars arranged around said permanent magnet, spaced apart by an angle which corresponds to the angular spacing of the magnet arms, one set of these conducting bars leading from said permanent magnet to the arms of one of the two flux conducting memberswhich are displaced from one another in the direction of rotation as the angular spacing of the magnet arms, a second set of these conducting bars leading to the arms of the second flux conducting member, a coil core, said fiux conducting bars, said two flux conducting members and the coil core being in conducting connection with each other, and adapted to conduct the flux furnished by said permanent magnet and distributed to the two sets of flux conducting bars through said armature coil, 9. magneto-housing proper made of non-magnetic material, a contact breaker, a high tension distributor, a top cap, a drive shaft for the contact breaker and the high tension distributor being fixed to said permanent magnet and extending right through the hollow coil core and the flux conducting member, said top cap tension distributor, a bearing bracket for said drive shaft, a ring of non-magnetic metal firmly heldin the material of said magneto-housing and U-shaped m cross-section, having uneven lengths of limb, the shorter limb of which has equally spaced openings for guiding the flux conducting bars, which are firmly held in the material of said magneto-housing, whilst the longer limb of said ring is adapted to fix said magneto housing proper to said bearing bracket.

JAKOB BOHLI.

e, GOTTLIEB STEINER.

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