Long ironncoreless stator linear motor

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The present invention relates to a linear motor comprising a stator disposed on a track and equipped with fastening devices on the track, the conductors of the sliding field winding of said stator being embedded in a non-magnetic winding support.

A linear motor of this type is known from patent application DE 23 37 930. In the case of this motor, the vehicle carries two inductor windings whose coils are with horizontal axis and with which is associated, on the track, a winding with sliding field constituted by electrical conductors with rectangular section. The space between the electrical conductors and which surrounds them is filled with an electrically insulating material, namely an epoxy resin, a polyester resin, or the like, so that the assembly constitutes a rail. The conductors exit at both ends of the rail, which allows them to connect aligned rails. The rails thus aligned one after the other are fixed song on the track, using an intermediate support, and penetrate between the two windings of the inductor magnet housed on the vehicle. A particularly important drawback of this embodiment is that the elements protruding on the track create difficulties, in particular at crossings and branches.

A simple embodiment of the track and the switches is obtained by using, for the propulsion of the vehicle, a unilateral linear motor comprising an inductive winding with vertical coil axis, disposed on the vehicle, and a polyphase sliding field winding, produced in the form of a corrugated winding laid flat on the track (brochure AEG-BBC-SIEMEUS, Elektrodynamisches Schweben - Erlangen - Erprobungsstrecke ”,

E® control E 4lPM / l393, page 15) · In the case of this embodiment, the channel or line is subdivided into different supply sections and comprises a three-phase winding mounted in a star, supplied by a substation with mutator. The three-phase winding housed in the track interacts with an inductor winding produced on the vehicle in the form of a superconductive winding.

The object of the present invention is to fix the conductors of the sliding field winding on the track in such a way that with mounting means reduced to a minimum, these conductors are located as close as possible to the air gap side of the linear motor. , and that a permanent fixing, keeping the conductors in place, is ensured.

From a linear motor of the type defined above, the present invention makes it possible to solve this problem by the fact that the stator is mounted flat on the track and that the conductors of the sliding field winding are conductors under sheath. , insulated and at least approximately circular, which are fixed individually in a formwork, using fixing means, in such a way that after introduction of a curable non-magnetic material into the formwork they are at least approximately flush with the external face of the stator, which faces the inductor magnet of the linear motor.

the sheathed conductors, at least approximately circular, can be bent without special tools to take the shape necessary for producing the sliding field winding, and they can be securely fixed in the curable material, to the upper face of the stator. It suffices that said curable material has good mechanical strength characteristics without having an electrical insulating power. In contrast to the known embodiment, no intermediate support is required for fixing the stator to the track, which results in a reduction in manufacturing costs.

It is particularly advantageous that plates serving as winding supports, and which can be aligned end to end, are used at least for the lower part of the formwork, and remain on the track as lost formwork. A track support, for example made of concrete, having a recess, for receiving the rolling field winding made up of continuous conductors in a sheath, can also serve as lost formwork. This makes it possible to considerably simplify the production of a linear motor with a long stator, and to facilitate assembly work at the place of installation, since prefabricated track elements can be used for the construction of the stator. Therefore, conductor junctions are practically necessary only at the beginning and at the end of a supply section.

According to an additional characteristic of the present invention, the means for fixing the sheathed conductors are constituted by transverse ribs arranged one beside the other and made in particular of a non-magnetic material, which form grooves between them intended for the fixing of the conductors under sheath in the formwork.

According to another characteristic of the present invention, the transverse ribs have prominences at given intervals, thereby narrowing the grooves.

According to another characteristic of the present invention, the sheathed conductors are constituted by multi-stranded conductors coated with a common insulating sheath.

According to another characteristic of the present invention, the means for fixing the sheathed conductors can be produced in the form of bars, hooks, or equivalent devices.

According to another characteristic of the present invention, the means for fixing the sheathed conductors in the formwork can be constituted by an adhesive, in particular by a contact adhesive.

According to an additional characteristic of the present invention, the curable material is added with a material having good thermal conductivity.

According to another characteristic of the present invention, the sliding field winding can be produced in the form of a single layer winding.

the present invention is better understood with the aid of the detailed description of several embodiments taken as nonlimiting examples and illustrated by the appended drawing, in which:

FIG. 1 is a cross section of a long stator of a linear motor, which is produced in a formwork,

FIG. 2 is a plan view of a long stator provided with fixing means for a rolling field winding,

- Figure 3 is a partial section along III-III of Figure 2>

FIG. 4 is a cross section of a stator produced using a lost lower formwork,

- Figure 5 is a view. plan of the stator shown in FIG. 4, the upper formwork being removed, and

- Figure 6 is a cross section of a stator whose formwork is constituted by a hollow track support ·

In the case of the long stator linear motor, the stator is arranged on the track, FIG. 1 represents a cross section of a stator 1 which is produced in a formwork 2, laid flat or on edge, and which is designed to so as to be able to be laid flat on the track, the conductors of the sliding field winding 3 provided in the stator are conductors in sheath 4, insulated and at least approximately circular, and which are fixed individually in the formwork 2 using fixing means 5 · the sheathed conductors 4 of the sliding field winding are fixed to the wall of the formwork 2 in the form of a bundle of cables, using of wires detachable from the outside, so that after introduction of a non-magnetic curable material 6, they are at least approximately flush with the outside face of the stator 1, which is opposite the inducting magnet 7 of the linear motor, the axis a of the winding of the inducting magnet 7 is perpendicular to the track, the hardenable material is concrete or another mass capable of hardening.

the stators 1 thus prefabricated in the factory are stripped after hardening and transported to the place of installation, the stators 1 are aligned end to end one after the other, flat on the track, to form a rail, and the different sections of the sliding field winding 3 are electrically connected to each other, at the ends 8 of the conductors, exited on the two longitudinal sides of the stators 1.

As shown in Figure 2, prefabricated winding supports 13 can advantageously serve as formwork for the long stator of the linear motor, and remain on the track as cGffrage lost. Transverse ribs 9, located next to each other, and in particular made of a non-magnetic material, form between them grooves 10 for fixing the sheathed conductors 4 in the formwork, and then advantageously serving as fixing means 5 for said conductors in sheath 4. Transverse ribs 9 facilitate the shaping of these conductors in sheath 4 of the sliding field windings. Transverse ribs 9 intended for fixing the various conductors in the sheath 4 of the sliding field windings advantageously occupy, for example, the width b of the active stator. The winding heads comprising, as fixing means, preferably bars 12 between which the conductors in the sheath 4 are clamped. To obtain a tight fit of the sheath conductors 4 located between the transverse ribs 9, it is intended that the latter have, at given intervals, protrusions 11 which make the grooves narrower. The sheath conductors 4 of the sliding field winding 3 preferably include, inside an insulating sheath 4a, a large number of individual conductors 4b (FIG. 3) · This facilitates installation in the formwork and placing in shape during assembly. In addition, the multi-strand conductors wrapped in a common insulating sheath allow a substantial reduction in braking losses (Poueault currents). The sheathed conductors can be unwound, from a cable drum, on the winding supports 13, in the form of continuous conductors, and be fixed there (FIG. 2). It is thus possible to dispense with junction points between the supply points.

After an electrical check, the winding supports 13 are provided with a side formwork 2 and a curable material is introduced therein, in particular a mass of curable synthetic resin, to permanently fix the winding. A separating joint 14a is provided between the winding supports 13 aligned end to end one after the other, and a wider separating joint 14b is placed in the zone of the winding head · An elastic mass ensuring compensation thermal expansion phenomena which occur in the winding supports 13 is introduced into these separation joints.

The bars 12, arranged in the winding support 13, serve as more reinforcements for the mass of synthetic resin and give the desired resistance to assembly with the winding support 13, which may be made of concrete. The transverse ribs 9 serve not only to fix the conductors in the sheath 4, but also to ensure a good junction with the winding support 13, since the mass of synthetic resin introduced is mainly subjected to compression and shearing forces when the linear motor works, and a stress by tensile forces is almost entirely removed (figure 3) · In addition, the use of transverse ribs 9 makes it possible to use a lesser quantity of curable synthetic resin for fixing the conductors under sheath 4, compared to the quantity of resin required in an arrangement without transverse ribs.

when a synthetic resin is used to fix the conductors in the sheath of the sliding field winding 3 with a single layer, the arrangement according to the present invention also makes it possible to subsequently remove the various conductors in the sheath, by heating the conductor concerned. If mechanical deterioration occurs, it is not essential to renew the entire section of track, the use of a sliding field winding with a single layer makes it possible to minimize the average interval between this winding and the inductor magnet 7, which improves the. efficiency and increases the power factor.

As fixing means for the conductors with round sheath 4 in the formwork 2, they can also use an adhesive, in particular a contact adhesive.

the transverse ribs or bars 9 used as fixing means for the sliding-field winding 3 can also occupy only small parts of the active width of the stator h as shown in FIGS. 4 and 5. This is particularly advantageous when is poured, around the rolling field winding 3, the same material as that used for the lost formwork serving as winding support 13, for example mortar or concrete. Hooks 15 serve as means for fixing the sliding-field winding 3 to the winding head of the stator 1. Bars 16 are used as reinforcement, which also improve the junction between the winding support 13 and the mass filling.

FIG. 6 represents a stator 1, in which a track support 17, having a recess 18 „serves as formwork. Transversal bars, studs or hooks, intended to fix the conductors under the sheath 4, penetrate into the recess 18. It is advantageous to add d⁸a material having good thermal conductivity the curable material 6 which is used to fix the conductors in sheath 4 ·