Connecting device for electrically connecting a three-phase motor

A connecting device for electrically connecting a three-phase motor having three windings (U, V, W) to a three-phase network. The connecting device comprises a mains connection unit (18; 68) for connecting the phase lines (L1, L2, L3) of the three-phase network, and a motor connection unit (14; 110) for connecting the six winding ends (U1, U2, V1, V2, W1, W2) of the three-phase motor. An exchangeable coupling module (16; 70, 72; 70, 72′) is furthermore provided, which is arranged between the mains connection unit and the motor connection unit and contains contacts and wiring elements electrically connecting the six winding ends (U1, U2, V1, V2, W1, W2) in a predefined manner to the three phase lines (L1, L2, L3) of the three-phase network.

BACKGROUND OF THE INVENTION

The invention relates to a connecting device for electrically connecting a three-phase motor.

Three-phase motors having at least three windings and being adapted to be connected to a three-phase network which comprises three electrical phase lines having phase-shifted alternating voltages are known. Such three-phase motors are used in a star connection or in a delta connection depending on the application. Depending on the selected connection, the ends of the windings of the three-phase motor have to be connected in different manners known per se to the phase lines of the three-phase network. The way of connecting the windings to the phase lines also determines the direction of rotation of the motor.

In the prior art, the wiring is realized manually in situ in a so-called motor connection box into which the motor winding terminals and the phase lines are guided. This wiring is very time-consuming and in case of a change of the connection or of the direction of rotation of the motor, it requires a re-plugging of the corresponding terminals, which leads frequently to errors. Tests in which plug connectors are used for the coupling are also known. Here, the motor connection box is partially dispensed with. A change of the connection and of the direction of rotation however always requires a rewiring.

Document EP 2 086 066 discloses as a post-published document a connecting device for electrically connecting a multiphase electric motor to a power source, which is made up of a connection box and a substantially cylindrical adapter.

Document DE 20 2006 016 472 U1 discloses a connector plug unit for three-phase motor units having a bridge circuit module within the connector housing. A bridge circuit is realized in the bridge circuit module, which is required for driving the three-phase motor unit by means of a delta connection.

Documents U.S. Pat. No. 3,525,971, FR 2617651 and DE 30 43 538 A1 each disclose plug connectors which can cause a reversal of the direction of rotation of a motor connected to a three-phase network by a rotated mounting or by interposing an adapter.

An object of the invention is to make the motor connection box, also known as motor terminal box, unnecessary. It is also an object of the invention to permit the electrical connection on the cable side using a connecting device by means of which both the direction of rotation of the motor and the type of the connection used can be selected in situ without a manual re-plugging/rewiring of the motor winding ends being necessary in case of a change of the connection or of the direction of rotation of the motor.

SUMMARY OF THE INVENTION

The invention provides a connecting device for electrically connecting a three-phase motor having at least three windings to a three-phase network, which comprises a mains connection unit for connecting the phase lines of the three-phase network, and a motor connection unit for connecting the at least six winding ends of the three-phase motor. An exchangeable coupling module is arranged between the mains connection unit and the motor connection unit and contains contacts and wiring elements electrically connecting the six winding ends in a predefined manner to the three phase lines of the three-phase network. A motor connection box in which re-plugging works are to be performed in order to change the connection is therefore no longer necessary. The desired connecting is realized in situ by means of the exchangeable coupling module without conductors having to be contacted with high expenditure.

In one embodiment of the invention, a first coupling module is provided which connects the three windings of the three-phase motor in a delta connection, and a second coupling module is provided, which connects the three windings in a star connection. In order to switch from a delta connection to a star connection, it is therefore not necessary to detach the terminals of the winding ends on the motor side of the motor connection unit, and the phase terminals on the mains connection unit also remain unaffected. It is merely necessary to exchange the coupling module.

The coupling module, or each of the coupling modules, is adapted to be mounted so as to be rotated through 180° along a coupling direction, i.e. along an axis leading from the mains connection unit to the motor connection unit. Due to this rotation of the coupling module, the direction of rotation of the motor is reversed. The terminals on the mains connection unit and on the motor connection unit thus remain unaffected also in case of a change of the direction of rotation.

Preferably, the mains connection unit has one terminal for each of the three phase lines, the terminal branching in two parallel phase contacts in the direction to the coupling module, the coupling module or each of the coupling modules each electrically contacting only one of the parallel phase contacts.

In a preferred embodiment, the motor connection unit has on the side facing the coupling module winding contacts to the six winding ends which are arranged in two groups of three winding contacts each, which are point symmetric to each other. This can involve an arrangement on two parallel straight lines, or the winding ends can also be arranged in a respective semicircle, the two semicircles being arranged so as to form a circle, for example.

In the first group, the winding beginning of a first winding, the winding end of a third winding, and the winding beginning of the third winding are arranged side by side, and in the second group, the winding end of the first winding is point symmetric to the winding beginning of the first winding, the winding beginning of the second winding is point symmetric to the winding end of the third winding, and the winding end of the second winding is point symmetric to the winding beginning of the third winding. It is therefore ensured that in case of a rotation of the coupling module through 180°, the direction of rotation of the motor is changed since other winding beginnings or winding ends thus contact the phase lines.

In another embodiment of the invention, the coupling module comprises an exchangeable bridge module which contains the wiring elements. A first bridge module is provided which contains wiring elements such that the three windings of the motor are connected in a delta connection. A second bridge module is further provided which contains wiring elements such that the three motor windings are connected in a star connection. In this embodiment, only part of the coupling module has to be exchanged in order to change the connection. It is however of course also possible to exchange the entire coupling module which is provided with the first bridge module, for example, for a different coupling module which is provided with the second bridge module.

The mains connection unit can be mounted to the coupling module in two positions that are rotated through 180° with respect to each other in order to connect the phase lines of the three-phase network. Due to the rotation of the mains connection unit, a change of the direction of rotation of the motor can be produced.

The connecting device is configured in a parallelepipedal manner for both embodiments.

The phase lines of the three-phase network are preferably firmly connected to the mains connection unit. This is preferably realized by means of clamping spring connections.

The connecting device is furthermore configured such that the six winding ends on the motor connection unit are adapted to be firmly connected, preferably as a crimp connection.

DETAILED DESCRIPTION OF THE DRAWINGS

First Example Embodiment

FIG. 1shows a connecting device10of a first example embodiment in a schematized form. The connecting device10comprises a motor connection unit14, an exchangeable coupling module16,16′ and a mains connection unit18which are connected to each other by means of plug-in connections.

On its side facing the coupling module16,16′, the motor connection unit14has six winding contacts20,22,24,26,28and30. The other side of the motor connection unit14that is not visible is provided with terminals which are electrically connected to the winding contacts20,22,24,26,28and30and to which the winding ends of a three-phase motor can be coupled, preferably via a crimp connection. The motor windings of a three-phase motor are usually designated by U, V and W, each motor winding having two ends. The six winding contacts20,22,24,26,28and30are therefore connected to the motor winding ends U1, U2, V1, V2, W1and W2. The six winding contacts are arranged in two groups each having three contacts.

To explain the connecting device according to the invention, reference is made by way of example to a three-phase motor having three windings. The connecting device can of course also be used in multipolar machines in which two windings respectively belong to one phase.

On its side facing the motor connection unit14, the coupling module16,16′ has six winding connecting contacts which are suitable for electrically contacting the winding contacts20,22,24,26,28and30. Here, the winding connecting contacts on the coupling module and the winding contacts on the motor connection unit are arranged in two groups such that an electrical contact is permitted in two positions rotated through 180° with respect to each other, i.e. the arrangement of the contacts must be point symmetric to an axis of rotation extending from the side facing the motor connection unit14to the side of the coupling module16,16′ facing the mains connection unit18and about which the coupling module can be rotated. The winding connecting contacts are not visible inFIG. 1. On the side facing the mains connection unit18, the coupling module has three phase connecting contacts32,34,36. The phase connecting contacts32,34,36serve to contact the phase lines L1, L2and L3of a three-phase network via the mains connection unit18. Within the coupling module16,16′, the phase connecting contacts are electrically connected to the winding connecting contacts arranged opposite thereto. Here, the two outer winding connecting contacts of one of the groups of winding connecting contacts are connected to the phase connecting contacts32and36, and the centre winding connecting contact of the other group is connected to the phase connecting contact34. The other winding connecting contacts end as blind contacts to the outside on the side facing the mains connection unit18. The outer contacts of the coupling modules16and16′ do not differ from each other. The coupling modules only differ from each other in their inner wiring elements which realize a delta or a star connection. To easily distinguish the various coupling modules from each other, they can be configured in different colors so that a simple optical distinction is possible.

On its side facing away from the coupling module16,16′, the mains connection unit18has three terminals38,40,42for connecting the phase lines L1, L2, L3of the three-phase network. The terminals38,40,42are preferably configured as clamping spring connection terminals to which the phase lines can be coupled in a rapid and reliable manner.

As shown inFIG. 1, the terminals38,40,42each branch in two parallel terminals which are guided to the side of the mains connection unit18facing the coupling module16,16′ and end there as phase contacts44,46,48,50,52and54. In the present example, terminal38is provided for a connection of phase line L1and branches in phase contacts44and46. Terminal40is provided for a connection of phase line L2and branches in phase contacts48and50. Terminal42is provided for a connection of phase line L3and branches in phase contacts52and54. On its side facing the coupling module16,16′, the mains connection unit18thus has six phase contacts44,46,48,50,52and54, two parallel terminals being respectively connected to each other within the mains connection unit18and contacting the same phase of the three-phase network.

The phase connecting contacts32,34,36of the coupling module16,16′ and the phase contacts44,46,48,50,52and54of the mains connection unit18are configured such that one of the phase contacts that are electrically connected in parallel is respectively contacted by the phase connecting contacts32,34,36of the coupling module16,16′, and the respective other phase contact of the phase contacts that are electrically connected in parallel is contacted upon rotation of the coupling module through 180° about a longitudinal axis.

FIG. 2shows the connecting device10from a slightly different perspective. Here, the motor connection unit14which is represented in a strongly schematized manner inFIG. 1, is shown in more detail. Three of the winding contacts20,22,24can be seen inFIG. 2, which are adapted to be electrically connected to the winding ends of the three-phase motor in the motor connection unit14on the side facing the coupling module. The coupling module16,16′ is inserted into the motor connection unit14. A coding piece56can be arranged in the motor connection unit14next to the coupling module16,16′ to thus avoid an undesired rotation of the coupling module during insertion. As will be explained below, the coupling module16,16′ can be mounted in two positions rotated through 180° with respect to each other to thus reverse the direction of rotation of the motor.

The mains connection unit18comprises the terminals38,40,42like inFIG. 1. On the side facing away from the coupling module, the mains connection unit18further has additional schematically outlined terminals. They serve, for example, to apply ground, the protective earth, to realize a motor braking function, and/or the neutral conductor, and are also further guided to the motor connection side. They are however not relevant to the function of the connecting device according to the invention and are therefore not discussed in further detail.

FIG. 3shows the mains connection unit18as viewed from the coupling module side, with the six phase contacts44,46,48,50,52and54. A coding piece56is inserted. It is marked with an “R” for right-hand rotation, and an arrow additionally indicates the direction of rotation of the motor. The coupling module16,16′ can only be inserted in one fitting position when the coding piece56is inserted, as a nose58on the coding piece56cooperates with a recess60on the coupling module16,16′. It is of course also possible to use other coding possibilities known to a person skilled in the art.

On the coupling module16,16′, the winding connecting contacts are visible which can electrically contact the winding contacts20,22,24,26,28and30of the motor connection unit14.

Depending on the application, three-phase motors are operated in a so-called delta connection or a star connection. Invisible wiring elements in the coupling module16,16′ ensure the desired connection between the motor winding ends and the phase lines.

FIG. 4ashows the electrical circuit diagram for a delta connection. The ends of the three windings U, V and W of the three-phase motor are connected in a triangular shape, that means that the winding end U2of the motor winding U is connected to the winding beginning W1of the motor winding W, the winding end W2of the motor winding W is connected to the winding beginning V1of the motor winding V, and the winding end V2of the motor winding V is connected to the winding beginning U1of the motor winding U. The phase lines are connected to the respective winding beginnings, which means that the phase line L1is connected to the winding beginning U1, the phase line L2is connected to the winding beginning V1, and the phase line L3is connected to the winding beginning W1.

FIG. 4bshows in a schematic top view the phase contacts44,46,48,50,52and54of the mains connection unit18as circles, dotted lines64respectively enclosing the two phase contacts which are electrically arranged in parallel and contact the same phase line. The winding contacts20,22,24,26,28and30of the motor connection unit14are arranged so as to coincide with the phase contacts of the mains connection unit18. For a better comprehension, the phase lines L1, L2and L3associated with the phase contacts are directly inserted inFIG. 4bjust as the winding ends U1, U2, V1, V2, W1and W2which are coupled to the winding contacts. The winding contacts20to30of the motor connection unit14are positioned in two groups that are point symmetric to each other, which means that three winding contacts are respectively arranged side by side, and the other three winding contacts are also arranged side by side on a straight line parallel thereto. According toFIG. 4b, in the first group, the winding beginning U1of the motor winding U, the winding end W2of the motor winding W, and the winding beginning of the motor winding W1are arranged side by side. The winding end V2of the winding V, next thereto the winding beginning V1of the winding V and the winding end U2of the winding U are arranged thereabove in a point symmetric arrangement.

In the schematic representation, a coincident representation of the phase contacts and of the winding contacts has been chosen. In the practical realization, the contacts need not be coincident since the electrical contact is realized via the coupling module arranged therebetween.

The three phase connecting contacts32,34,36of the coupling module16are drawn as rectangles. The fitting position shown corresponds to the fitting position shown inFIG. 1. The coupling module16is a coupling module for a coupling in a delta connection. Wiring elements62each connecting opposite contacts to each other are therefore contained in the coupling module.

The phase connecting contact32of the coupling module16establishes an electrical contact to the phase contact44of the mains connection unit18, which for its part is connected to the phase line L1of the three-phase network. The phase connecting contact32is electrically connected to the opposite winding connecting contact within the coupling module16, which is connected to the winding beginning U1via the motor connection unit. U1is thus connected to the phase L1. U1is further connected to V2via a wiring element62.

The phase connecting contact34of the coupling module16establishes an electrical contact to the phase contact50of the mains connection unit18, which for its part is connected to the phase line L2of the three-phase network. The phase connecting contact34is electrically connected to the opposite winding connecting contact within the coupling module16, which is connected to the winding beginning V1via the motor connection unit. V1is thus connected to the phase L2. V1is further connected to W2via a wiring element62.

The phase connecting contact36of the coupling module16establishes an electrical contact to the phase contact52of the mains connection unit18, which for its part is connected to the phase line L3of the three-phase network. The phase connecting contact36is electrically connected to the opposite winding connecting contact within the coupling module16, which is connected to the winding beginning W1via the motor connection unit. W1is thus connected to the phase L3. W1is further connected to U2via a wiring element62.

The contacting according toFIG. 4bthus results in a connection of the motor windings to each other and to the phases of the three-phase network according to the circuit diagram ofFIG. 4a.

FIG. 5aalso shows the connection of the motor windings U, V and W for a delta connection, but with a different direction of rotation. That means that the phase lines L1and L2are exchanged with respect to the representation inFIG. 4a.

FIG. 5bshows the corresponding association of the contacts of the motor connection unit14, of the mains connection unit18and of the coupling module16. As a delta connection is again involved, the same coupling module16as in the connection according toFIG. 4ais used. This means that the wiring elements62each connect opposite contacts. In comparison withFIG. 4b, the coupling module16has been mounted so as to be rotated through 180° about an axis extending between the motor connection unit14and the mains connection18along the coupling direction. Therefore, the phase connecting contact36of the coupling module16now contacts the phase line L2via the phase contact48, the phase connecting contact34of the coupling module16contacts the phase contact46connected to the phase line L1, and the phase connecting contact32of the coupling module contacts the phase contact54of the mains connection unit18which is connected to the phase line L3. The position of the winding contacts is unchanged, i.e. the phase L2is connected to V2and to U1via a wiring element62, the phase L1is connected to W2and to V1via a wiring element62, and the phase L3is connected to U2and to W1via a wiring element62. The direction of rotation of the motor is therefore reversed as desired. The fitting position of the coupling module desired for this direction of rotation can for its part be fixed by means of a corresponding coding piece56.

FIG. 6ashows the electrical circuit diagram for a star connection of the motor windings U, V and W. For this purpose, the motor winding ends U2, V2and W2are electrically connected, whereas the phase line L1is connected to the winding beginning U1, the phase line L2is connected to the winding beginning V1, and the phase line L3is connected to the winding beginning W1.

FIG. 6bcorrespondingly shows the configuration of the connecting contacts on the motor connection unit14, the coupling module16′ and the mains connection unit18. The coupling module16has been replaced with a coupling module16′ for a star connection, which externally corresponds to the coupling module16. The coupling module16′ contains wiring elements66which connect the winding connecting contacts to each other, which are not connected to phase connecting contacts32,34,36.

The arrangement of the winding ends U1, U2, V1, V2, W1and W2on the motor connection unit14, and of the phase lines on the mains connection unit18remains unchanged with respect toFIGS. 4band5b. In the fitting position illustrated inFIG. 6b, a rectangularly represented phase connecting contact32′ of the coupling module16′ contacts the phase contact44of the mains connection unit18and thus the phase line L1and the winding beginning U1via the motor connection unit, a phase connecting contact34′ of the coupling module16′ contacts the phase contact50of the mains connection unit18and thus the phase line L2and the winding beginning V1, and a phase connecting contact36′ of the coupling module16′ contacts the phase contact52of the mains connection unit18and thus the phase line L3and the winding beginning W1. The winding ends V2, W2and U2are not connected to a phase line, they are however connected to each other via wiring elements66. The electrical connection represented inFIG. 6ais therefore obtained.

FIG. 7ashows the electrical circuit diagram for connecting the motor windings U, V and W for a star connection with a reversed direction of rotation with respect to the connection ofFIG. 6a. The winding beginnings U1, V1and W1are electrically connected to each other, whereas the winding end U2is connected to the phase line L3, the winding end V2to the phase line L2, and the winding end W2to the phase line L1.

FIG. 7bshows the contact with the coupling module16′ which has been rotated through 180° along an axis in the coupling direction. Therefore, the wiring elements66now electrically connect the winding beginnings U1, V1and W1to each other. In the fitting position illustrated inFIG. 7b, the rectangularly represented phase connecting contact32′ of the coupling module16′ contacts the phase contact54of the mains connection unit18and thus the phase line L3and the winding end U2via the motor connection unit, the phase connecting contact34′ of the coupling module16′ contacts the phase contact46of the mains connection unit18and thus the phase line L1and the winding end W2, and the phase connecting contact36′ of the coupling module16′ contacts the phase contact48of the mains connection unit18and thus the phase line L2and the winding end V2.

In the present case, the orientation of the coupling module can also be fixed by means of a coding piece56.

It is therefore possible in a simple manner to realize a connection of the three-phase motor to a three-phase network without having to re-plug the connecting lines. The distinction between the delta connection and the star connection is realized by the selection of the appropriate coupling module16,16′, and the reversal of the direction of rotation is realized by the fitting position of the coupling module. To rotate the coupling module, the motor connection lines and the mains connection lines need not be detached, and it is merely necessary to extend the connecting device and to rotate the coupling module, after which the connecting device can be reassembled. The entire connecting device can be realized within the cable in the form of a plug-in connection, so that a change of the connection and/or of the direction of rotation in situ is possible without using a tool.

Second Example Embodiment

FIG. 8shows in a schematized three-dimensional representation a second embodiment of the connecting device according to the invention having a mains connection unit68, a coupling module70and two bridge modules72,72′ and a motor connection unit (not shown).

On a side facing the coupling module, the mains connection unit68has three phase contacts74,76and78. Within the mains connection unit68, the phase contacts74,76and78are electrically connected to three terminals (not shown) on the side facing away from the coupling module, to which the three phase lines L1, L2and L3of a three-phase network can be coupled. The terminal of the phase lines L1, L2and L3can preferably be realized via clamping spring connections. The mains connection unit can be fitted into the coupling module70in two fitting positions rotated through 180° with respect to each other in the direction of insertion.

The coupling module70has an exchangeable bridge module,FIG. 8showing a first bridge module72and a second bridge module72′ which can be used alternatively. Externally, the two bridge modules have the same structure. They differ from each other in wiring elements that are not illustrated such that a delta connection is obtained by means of the bridge module72, whereas by means of the second bridge module72′, due to the wiring elements contained therein, the three motor windings can be connected to each other and to the phase lines so as to obtain a star connection.

On their side facing the coupling module70, the bridge modules72,72′ each have three phase connecting contacts via which they directly electrically contact the three phase contacts74,76and78of the mains connection unit68. On the side facing away from the coupling module70, the bridge modules72,72′ each have 6 winding connecting contacts80to90or92to102, respectively, which are suitable for electrically contacting winding contacts on the motor connection unit that is not illustrated. The winding connecting contacts80,82and84, or92,94and96, respectively, which are arranged on the top inFIG. 8, are each electrically connected to the phase connecting contacts opposite thereto, whereas the winding connecting contacts86,88and90or98,100and102, respectively, which are arranged at the bottom, are connected to the winding connecting contacts on the top in different manners depending on the bridge module. In practice, the terminals92,94and96can however be dispensed with.

In the case of the bridge module72, for example, the winding beginning U1can be connected to the winding connecting contact80, the winding beginning V1can be connected to the winding connecting contact82, and the winding beginning VV1can be connected to the winding connecting contact84via the motor connection unit, whereas the winding connecting contact86contacts the winding end W2, the winding connecting contact88contacts the winding end U2, and the winding connecting contact90contacts the winding end V2via the motor connection unit.

For a delta connection, the bridge module72then has a plurality of wiring elements which connect the winding connecting contacts80and86, the winding connecting contacts82and88, and the winding connecting contacts84and90, respectively, to each other to thus obtain a contact U1-W2, V1-U2and W1-V2.

Correspondingly, for a star connection, the bridge module72′ has the winding connecting contacts92,94and96in an upper row, which as in the bridge module72are associated with the winding beginnings U1, V1and W1, and the winding connecting contacts98,100and102in a lower row which are correspondingly associated with the terminals W2, U2and V2. The bridge module72′ contains wiring elements which connect the lower three winding connecting contacts98,100and102, i.e. W2-U2-V2to each other so that a star connection is obtained.

The connection of the motor winding ends on the motor connection unit thus always remains the same, a crimp connection being preferably provided for the connection. In this embodiment, it is also possible to switch between the delta connection and the star connection in a simple manner by exchanging the bridge module without a re-plugging of the terminals being necessary.

For a change of the direction of rotation of the motor irrespective of the bridge module used, it is provided in the second embodiment that the mains connection unit68can be fitted in two positions rotated through 180° with respect to each other such that the reversal of the direction of rotation of the connected three-phase motor is thereby obtained. By way of example, the phase contact74is connected to the phase line L1via the mains connection unit68, the phase contact76is connected to the phase line L2, and the phase contact78is connected to the phase line L3. In the fitted position shown inFIG. 8, using the bridge module72, the phase line L1is then connected to the winding connecting contact80and thus to the winding beginning U1, the phase line L2is connected to the winding connecting contact82and thus to the winding beginning V1, and the phase line L3is connected to the winding connecting contact84and thus to the winding beginning W1. Upon rotation of the mains connection unit through 180°, the phase line L1contacts the winding beginning W1, and the phase line L3contacts the winding beginning U1, that means that the direction of rotation of the motor is reversed.

The same applies to the use of the bridge module72′.

FIG. 9shows the connecting device according toFIG. 8in the assembled state with a mounted bridge module72′. The second embodiment also provides more than the six winding terminals on the motor side, the protective earth, the neutral conductor and a further ground line of the three-phase network being for example adapted to be connected to the motor via the terminals104,106and108. These lines are not relevant to the present invention and are thus not discussed in more detail.

FIG. 10schematically shows in a three-dimensional representation a connecting device as represented inFIGS. 8 and 9, which is partially cut open and has a separated motor connection unit110.FIG. 10shows the coupling module70with a mains connection unit68inserted and a bridge module72or72′. The motor connection unit110is connected to the coupling module and encloses the bridge module72,72′. On the right-hand side ofFIG. 10, the motor connection lines can thus be firmly connected to the mains connection unit, whereas on the left-hand side, the phase line of the three-phase network can be firmly connected to the mains connection unit68.

A person skilled in the art knows different ways of connecting mains cables and motor connection lines via plug-in connections. In both embodiments, the phase lines are preferably connected to the mains connection unit via clamp spring connections.

For connecting the motor lines to the motor connection unit, a crimp connection is preferred.

Both embodiments also have in common to present a substantially parallelepipedal structure. The invention is however not restricted to an external parallelepipedal shape, a cylindrical shape is for example also conceivable. In the first embodiment, it is in particular only decisive for the connecting structure of the winding ends that the terminals are arranged in two groups of three terminals each, the terminals being point symmetric to each other such that the rotation of the coupling module through 180° leads to the desired reversal of the direction of rotation of the motor.