Patent Description:
Hybrid and full electric vehicles comprise an electric power accumulator, regularly a battery, and a motor to drive the wheels of the vehicle. An inverter is arranged in between the electric power accumulator and the motor to converge the accumulated power of the electric power accumulator and to supply the electric power to the motor. In recent times these electric drive units became more integrated to reduce costs and packaging of the drive units. However, even in such configurations, the busbars of the inverter need to be connected to electrical connectors of the motor by an electrical conductor to span the offset of the inverter busbar and the electrical connector of the motor.

<CIT> discloses a connector assembly including a connection element having an intermediate bus bar. The connection element is inserted into a connection plate that includes a plurality of positioning pins. The connection plate is screwed to a generator housing such that the connection element is arranged clamped between the connection plate and the generator housing.

<CIT> discloses a terminal block assembly including a housing having a plurality of bus bars attached thereto and having a positioning pin. The bus bars can be connected to a current sensor with their end portion facing away from the motor.

<CIT> discloses a further example of a connector assembly for electrically connecting an inverter busbar to an electrical connector of an electric motor of a drive unit.

<CIT> discloses a device connector comprising a housing main body to which a plurality of terminal fittings are attached and which has a plurality of positioning pins. The terminal fittings have bolt holes at a wire side connecting portion, which merge substantially continuously into nuts <NUM>.

A connector assembly as is initially described is disclosed in <CIT>. An inverter terminal board mounts an electrical conductor which is formed by a busbar integrally including an inverter site connecting terminal and motor site connecting terminal.

In the <CIT> a second embodiment of a connector assembly is disclosed, wherein an inverter terminal board mounts an electrical conductor which connects an inverter site connecting terminal and motor site connecting terminal by braided wire.

Object of the present invention is to provide a connection of an inverter busbar to an electrical connector of a drive unit to span the nominal offset between the inverter busbar and the electrical connector that compensates for position deviations between the inverter busbar and the electrical connector while reducing static loads of the inverter busbar and that is resilient to vibrations.

The object is achieved by a connector assembly for electrically connecting an inverter busbar to an electrical connector of a drive unit comprising: a carrier having a hole, an intermediate busbar comprising a first terminal with a hole, a first fastening element extending through the hole of the first terminal, and a third fastening element, wherein the intermediate busbar is mounted to the carrier and the intermediate busbar is connectable to the inverter busbar by the first fastening element, wherein the carrier comprises a positioning pin defining a longitudinal axis, said positioning pin being adapted to be accommodated in a receptacle of a housing of the drive unit such that the carrier is axially slidable in the direction of the longitudinal axis; the first fastening element is arranged within the hole of the first terminal with a radial clearance relative to the longitudinal axis of the positioning pin, and the carrier is connectable to the housing of the drive unit by the third fastening element extending through the hole of the carrier, wherein the third fastening element is arranged within the hole of the carrier with a clearance in a direction parallel to the longitudinal axis of the positioning pin.

The connector assembly according to the invention has the advantage that the position deviations between the inverter busbar and the electrical connector can be compensated without the use of wires. Wires are vulnerable to vibrations induced for example from the drive unit itself or by vehicle movement limiting the lifetime of the connector assembly. Furthermore, the inventive connector assembly induces no static loads on the inverter busbar after connecting the intermediate busbar to the inverter busbar. Tensioning of the inverter busbar in a direction parallel to the longitudinal axis of the positioning pin is avoided by the slidable arrangement of the positioning pin respectively the carrier. Tensioning of the inverter busbar in a direction radial to the longitudinal axis of the positioning pin is avoided through the radial clearance between the first fastening element and the hole of the first terminal. Furthermore, additional external loads on the connector assembly such as vibrations will be beard by the positioning pin. Further, mounting the carrier onto the housing of the drive unit prevents the connector assembly from oscillating, for example due to the excitation from the motor or from the vehicle body movement. Furthermore, it can be avoided that further external loads acting in a direction parallel to the longitudinal axis of the positioning pin on the inverter busbars via the carrier are induced while mounting the carrier onto the housing of the drive units.

In the context of the present disclosure a radial clearance relative to the longitudinal axis of the positioning pin between first fastening element and the hole of the first terminal shall be understood to include any clearance between the first fastening element and the hole of the first terminal in a plane extending radially to the longitudinal axis of the positioning pin.

In the context of the present disclosure a busbar shall be meant to include as an electrically conductive strip or bar that can be considered as reasonable stiff, in particular as stiff compared to a wire. Furthermore, a hole shall be understood as every opening extending through an element, wherein the opening can have a closed profile such as a bore or an open profile in a radial direction relative to a longitudinal axis of the hole such as a slot or a recess.

Moreover, the locating pin can have every cross-sectional profile that allows the locating pin to slide inside a receptacle along its longitudinal axis. For example the locating pin can have a round, oval or rectangular cross-sectional profile. It is also conceivable, that the cross-sectional profile of the locating pin is crescent-shaped or has a shape of a curved rectangular. The span from one end of the cross-sectional profile to another end can be larger than the extent of the locating pin in the direction of the longitudinal axis.

To compensate analytically determined maximum position deviations between the inverter busbar and the electrical connector of the drive unit, the nominal radial clearance of the first fastening element and the hole of the first terminal can be for example <NUM> and more.

The connector assembly can be configured to connect one or more inverter busbars to one or more electrical connectors. In particular, the connector assembly can be configured to connect three inverter busbars to three electrical connectors via three intermediate busbars.

In case the connector assembly is configured to connect at least two inverter busbars to two electrical connectors the carrier can comprise a rib or ribs configured to separate two adjacent intermediate busbars, respectively two adjacent electrical connectors, and/or two inverter busbars from each other.

The carrier can be made at least partially out of an electrical insulating material to avoid any short-circuits between the intermediate busbars and/or the inverter busbars.

In an embodiment of the invention the connector assembly can comprise a second fastening element and the intermediate busbar can have a second terminal with a hole, wherein the second fastening element extends through the hole of the second terminal for establishing a connection between the intermediate busbar and the electrical connector of the drive unit. In this embodiment the carrier can comprise a threaded bore receiving the second fastening element. For this, the carrier can comprise a threaded insert provided with said threaded bore made of an electrically conductive material. In addition or alternatively, the threaded insert of the carrier can be made of a metallic material to avoid unwanted loosening of the fastening elements.

Furthermore, the second fastening element can be arranged within the hole of the second terminal of the intermediate busbar with a clearance in a direction parallel to the longitudinal axis of the positioning pin. In this way tensioning between the intermediate busbar and the electrical connector of the drive unit in a direction parallel to the longitudinal axis of the positioning pin can be avoided. Moreover, the second fastening element can be arranged within the hole of the second terminal of the intermediate busbar with a clearance at least in a direction perpendicular to the longitudinal axis of the positioning pin.

In a further embodiment of the invention the carrier can comprise an insert with a hole made of an electrically conductive material, wherein the first fastening element is arranged inside the hole of the insert and the insert is in contact with the first fastening element and the intermediate busbar. With this embodiment the current from the inverter busbar can be transmitted to the intermediate busbar with a sufficiently low contact resistance. In addition or alternatively, the insert of the carrier can be made of a metallic material to avoid unwanted loosening of the fastening elements.

To compensate maximum position deviations between the inverter busbar and the electrical connector of the drive unit, the nominal clearance in a direction parallel to the longitudinal axis of the positioning pin between the third fastening element and the hole of the carrier can be for example <NUM> and more. Furthermore, the third fastening element can be arranged within the hole of the carrier with a clearance at least in a direction perpendicular to the longitudinal axis of the positioning pin. Particularly, the clearance can be chosen as to considering standardized clearances for the third fastening element.

For instance, the hole of the carrier can have an elongated shape or it can be a slot open in a direction parallel to the longitudinal axis of the positioning pin.

The object is further achieved by a drive unit comprising: a housing with a receptacle, an inverter busbar for an electrical connection with an inverter, an electrical connector for an electrical connection with an electrical load, and a connector assembly according to any one of the preceding claims, wherein the positioning pin is accommodated within the receptacle of the housing, slidable in an axial direction, and the intermediate busbar is connected to the inverter busbar by the first fastening element.

The drive unit shows the same advantages as the inventive connector assembly alone. Therefore, reference is made here to the related explanation above.

The axial direction in which the positioning pin is slidable accommodated within receptacle of the housing is parallel to the longitudinal axis of the positioning pin.

The receptacle of the housing has a cross-sectional profile that allows the positioning pin to slide inside the receptacle along the longitudinal axis of the positioning pin. In particular, the cross-sectional profile of the receptacle is complementary to the cross-sectional profile of the locating pin. In particular, the cross-sectional profile of the receptacle can be round, oval, rectangular, crescent-shaped or can have a shape of a curved rectangular.

In an embodiment of the drive unit the intermediate busbar can be connected to the electrical connector by the second fastening element. Thus, a fixed connection between the intermediate busbar and the electrical connector can be established to avoid significant relative motion between these two parts.

In another embodiment of the drive unit the electrical connector can comprise a hole through which the second fastening element extends, wherein the second fastening element is arranged within the hole of the electrical connector with a clearance in a direction parallel to the longitudinal axis of the positioning pin. With this embodiment it can be avoided that a tension force in parallel to the longitudinal axis of the positioning pin resulting from the connection between the electrical connector and the intermediate busbar is acting on the inverter busbar via the carrier. To compensate maximum position deviations between the inverter busbar and the electrical connector of the drive unit, the nominal clearance in a direction parallel to the longitudinal axis of the positioning pin between the third fastening element and the hole of the carrier can be for example <NUM> or more. Furthermore, the second fastening element can be arranged within the hole of the electrical connector with a clearance in a direction perpendicular to the longitudinal axis of the positioning pin.

In an embodiment of the drive unit the carrier can be connected to the housing by a third fastening element extending through a hole of the carrier, wherein a clamping force of the third fastening element is acting in a direction transversely to the longitudinal axis of the positioning pin. In particular, the clamping force can act in a direction so that a self-locking connection between the carrier and the housing is established, i.e. the friction force in the contact between carrier and housing induced by the clamping force exceeds the axial component of the clamping force With this embodiment it can be avoided that while fastening of the carrier to the housing a force parallel to the longitudinal axis of the positioning pin is acting on the inverter busbar via the carrier.

In a further embodiment of the drive unit can comprise a planar contact between the electrical connector and the intermediate busbar and/or a planar contact between the inverter busbar and the intermediate busbar. With this embodiment the current from the inverter busbar can be transmitted to electrical connector via the intermediate busbar with a sufficiently low contact resistance.

In an embodiment of the drive unit the first fastening element can be a first screw received in a threaded bore of the inverter busbar or by a nut. In another embodiment of the drive unit the second fastening element is a second screw received by the threaded bore of the carrier clamping the electrical connector between the intermediate busbar and the carrier.

Beyond that, the object of the invention is achieved by a method for electrically connecting an inverter busbar to an electrical connector of a drive unit by a connector assembly as described above, comprising the following steps: mounting the carrier with the intermediate busbar onto a housing such that the carrier is slidable in a first direction; bringing the intermediate busbar into contact with the inverter busbar by sliding the carrier in the first direction; fastening the intermediate busbar to the inverter busbar; and fastening the intermediate busbar to the electrical connector of the drive unit.

The inventive method has the advantage that the intermediate busbar can be connected to the inverter busbar without applying static loads on the inverter busbar.

An embodiment of the method can comprise the further step of positioning the electrical connector of the drive unit between the carrier and the intermediate busbar while mounting the carrier onto the housing.

Another embodiment of the method can comprise the further step of fastening the carrier to the housing after fastening the intermediate busbar to the electrical connector of the drive unit.

Subsequent, the invention will be described by way of example with reference to the accompanying Figures, wherein:.

<FIG> depict an exemplary embodiment of the inventive connector assembly <NUM> connecting inverter busbars <NUM>, <NUM>', <NUM>" to motor connectors <NUM>, <NUM>', <NUM>" of an electrical drive unit <NUM>.

The electrical drive unit <NUM> comprises an inverter <NUM> transmitting electrical power of a battery that is not represented in the Figures to an electrical motor <NUM>. The inverter <NUM> includes three inverter busbars <NUM>, <NUM>', <NUM>" for connecting the inverter <NUM> to the electrical load, wherein each of the inverter busbars <NUM>, <NUM>', <NUM>" is representing one electrical phase.

The inverter busbars <NUM>, <NUM>', <NUM>" have a flat shape in the present embodiment. However, also shapes divergent from flat can be conceived for the busbars <NUM>, <NUM>', <NUM>". The three inverter busbars <NUM>, <NUM>', <NUM>" are separated and electrically insulated to each other by an insulating cover <NUM>. At a free end, where no insulating cover is present, each of the inverter busbars <NUM>, <NUM>', <NUM>" is provided with a threaded bore <NUM>, <NUM>', <NUM>" to connect the inverter busbars <NUM>, <NUM>', <NUM>" to a connector assembly <NUM>.

The electric motor <NUM> comprises three motor connectors <NUM>, <NUM>', <NUM>" for connecting the electric motor <NUM> to an electric power source, which is in the present embodiment the battery. Each of the motor connectors <NUM>, <NUM>', <NUM>" includes a terminal <NUM>, <NUM>' that has a flat rectangular shape in the present embodiment. However, also shapes divergent from flat or rectangular can be conceived for the terminals <NUM>, <NUM>'. Each of the terminals <NUM>, <NUM>' comprises an elongated through-hole <NUM>, <NUM>'. In the Figures the terminal including the through-hole of the motor connector <NUM>" are concealed. A slot open to an end portion of the motor connectors <NUM>, <NUM>', <NUM>" would also be conceivable. The inverter busbars <NUM>, <NUM>', <NUM>" are connected to the motor connectors <NUM>, <NUM>', <NUM>" by the connector assembly <NUM> including the carrier <NUM> and three intermediate busbars <NUM>, <NUM>', <NUM>".

The carrier <NUM> of the connector assembly <NUM> is made at least partly out of an electrically insulating material and includes a first connecting portion <NUM> and a second connecting portion <NUM> that are arranged perpendicular to each other. Two stiffening ribs <NUM>, <NUM>' extend between the first connecting portion <NUM> and the second connecting portion <NUM> to reinforce the carrier and spatially separate the three intermediate busbars <NUM>, <NUM>', <NUM>" from each other.

The carrier <NUM> further comprises a positioning pin <NUM> defining a longitudinal axis L1. The positioning pin <NUM> is accommodated in a receptacle of the housing <NUM>, which is concealed in the Figures, such that the carrier <NUM> is slidable in a direction parallel to the longitudinal axis L1. External loads acting on the carrier <NUM> transversely to the longitudinal axis L1 will be beard by the positioning pin <NUM>. In the present embodiment the positioning pin <NUM> has a round profile along the longitudinal axis L1. However, all other profiles that allow the positioning pin <NUM> to slide in a receptacle of the housing <NUM> along the longitudinal axis L1 are conceivable, e.g. oval, rectangular, crescent-shaped or curved-rectangular-shaped. In this regard, the receptacle of the housing <NUM> can have a complimentary shape relative to the shape of the positioning pin <NUM>. The positioning pin <NUM> and the receptacle of the housing <NUM> can be formed so that a loose fit or transition fit is established between the positioning pin <NUM> and the receptacle of the housing <NUM>.

The intermediate busbars <NUM>, <NUM>', <NUM>" are mounted to the first connecting portion <NUM> of the carrier <NUM> such that they are fixed in the plane outlined by the first connecting portion <NUM> and slidable perpendicular to said plane. Each of the intermediate busbars <NUM>, <NUM>', <NUM>" comprises a first terminal <NUM>, <NUM>', <NUM>" that has in the present embodiment a flat shape complimentary to the shape of the inverter busbars <NUM>, <NUM>', <NUM>". Hereby, a planar contact between the first terminals <NUM>, <NUM>', <NUM>" of the intermediate busbars <NUM>, <NUM>', <NUM>" and the inverter busbars <NUM>, <NUM>', <NUM>" is ensured reducing the electrical contact resistance. To fix the intermediate busbars <NUM>, <NUM>', <NUM>" to the inverter busbars <NUM>, <NUM>', <NUM>", first fastening elements in the form of first screws <NUM>, <NUM>', <NUM>" extend through holes <NUM>, <NUM>', <NUM>" in inserts <NUM>, <NUM>', <NUM>" of the carrier <NUM>. Further, the first screws <NUM>, <NUM>', <NUM>" extend through holes <NUM>, <NUM>', <NUM>" in the first terminals <NUM>, <NUM>', <NUM>" of the intermediate busbars <NUM>, <NUM>', <NUM>" with a radial clearance relative to the longitudinal axis L1 of the positioning pin <NUM>. The first screws <NUM>, <NUM>', <NUM>" are accommodated in the threaded bores <NUM>, <NUM>', <NUM>" of the inverter busbars <NUM>, <NUM>', <NUM>" clamping the first terminals <NUM>, <NUM>', <NUM>" of the intermediate busbars <NUM>, <NUM>', <NUM>" in between the first connecting portion <NUM> of the carrier <NUM> and the inverter busbars <NUM>, <NUM>', <NUM>". Due to the radial clearance between the holes <NUM>, <NUM>', <NUM>" in the first terminals <NUM>, <NUM>', <NUM>" of the intermediate busbars <NUM>, <NUM>', <NUM>" and the first screws <NUM>, <NUM>', <NUM>" as well as the slidable arrangement of the positioning pin <NUM> within the receptacle of the housing <NUM> position deviations between the inverter busbars <NUM>, <NUM>', <NUM>" and the receptacle of the housing <NUM> can be compensated so that no static loads are applied to the inverter busbars <NUM>, <NUM>', <NUM>" by connecting the intermediate busbar <NUM>, <NUM>', <NUM>" to the inverter busbars <NUM>, <NUM>', <NUM>".

The holes <NUM>, <NUM>', <NUM>" of the inserts <NUM>, <NUM>', <NUM>" and the holes <NUM>, <NUM>', <NUM>" in the first terminals <NUM>, <NUM>', <NUM>" have the same diameter in the present embodiment. However, it is conceivable that the diameters of the holes <NUM>, <NUM>', <NUM>" of the inserts <NUM>, <NUM>', <NUM>" and the holes <NUM>, <NUM>', <NUM>" of the terminals <NUM>, <NUM>', <NUM>" differ. In particular, the diameter of the holes <NUM>, <NUM>', <NUM>" of the inserts <NUM>, <NUM>', <NUM>" can be larger than the diameter of the holes <NUM>, <NUM>', <NUM>" of the first terminals <NUM>, <NUM>', <NUM>".

The inserts <NUM>, <NUM>', <NUM>" can be made of an electrically conductive material to reduce the electrical contact resistance of the connection of the inverter busbars <NUM>, <NUM>', <NUM>" and the intermediate busbars <NUM>, <NUM>', <NUM>". In addition or alternatively, the inserts <NUM>, <NUM>', <NUM>" can be made of a metallic material to avoid unwanted loosening of the first fastening elements <NUM>,<NUM>',<NUM>".

The carrier <NUM> further comprises two guiding ribs <NUM>, <NUM>' that also can be called separation ribs. In assembled condition the first guiding rib <NUM> is received in a first gap <NUM> and the second guiding rib <NUM>' is received in a second gap <NUM>', wherein the first gap <NUM> is constituted by the free ends of the inverter busbar <NUM> and the inverter busbar <NUM>' and second gap <NUM>' is constituted inverter busbar <NUM>' and the inverter busbar <NUM>". Therefore, while sliding the positioning pin <NUM> respectively the carrier <NUM> along the longitudinal axis L1 the guiding ribs <NUM>, <NUM>' guide the carrier <NUM> into a dedicated position before connecting the intermediate busbars <NUM>, <NUM>', <NUM>" to the inverter busbar <NUM>, <NUM>', <NUM>". Furthermore, the guiding ribs <NUM>, <NUM>' spatially separate as well as electrically insulate the inverter busbars <NUM>, <NUM>', <NUM>" from each other.

Further, each of the intermediate busbars <NUM>, <NUM>', <NUM>" comprises a second terminal <NUM>, <NUM>', <NUM>" that has in the present embodiment a flat rectangular shape complimentary to the shape of the related terminal <NUM>, <NUM>' of the motor connectors <NUM>, <NUM>', <NUM>". Therefore, a shape of the second terminals <NUM>, <NUM>', <NUM>" that is diverging from flat or rectangular would also be conceivable. The second terminals <NUM>, <NUM>', <NUM>" of the intermediate busbars <NUM>, <NUM>', <NUM>" are arranged perpendicular to the first terminals <NUM>, <NUM>', <NUM>" of the intermediate busbars <NUM>, <NUM>', <NUM>" and parallel to the second connecting portion <NUM> of the carrier <NUM>. The second connecting portion <NUM> of the carrier <NUM> and the second terminals <NUM>, <NUM>', <NUM>" of the intermediate busbars <NUM>, <NUM>', <NUM>" are separated by the distance D1 defining a slot in which the terminals <NUM>, <NUM>' of the motor connectors <NUM>, <NUM>', <NUM>" are arranged.

Second fastening elements in the form of second screws <NUM>, <NUM>', <NUM>" are accommodated in threaded bores <NUM>, <NUM>', <NUM>" of inserts <NUM>, <NUM>', <NUM>" which are included in the carrier <NUM>. The second screws <NUM>, <NUM>', <NUM>" extend through holes <NUM>, <NUM>', <NUM>" in the second terminals <NUM>, <NUM>', <NUM>" of the intermediate busbars <NUM>, <NUM>', <NUM>" and the elongated through-holes <NUM>, <NUM>' of the terminals <NUM>, <NUM>' of the motor connectors <NUM>, <NUM>', <NUM>". The screw force of the second screws <NUM>, <NUM>', <NUM>" is clamping the motor connectors <NUM>, <NUM>', <NUM>" between the second connecting portion <NUM> of the carrier <NUM> and the intermediate busbars <NUM>, <NUM>', <NUM>".

In assembled condition the elongated through-holes <NUM>, <NUM>' of the terminals <NUM>, <NUM>' extend in a direction parallel to the longitudinal axis L1 of the positioning pin <NUM>. Thus, the second screws <NUM>, <NUM>', <NUM>" are arranged within the elongated through-holes <NUM>, <NUM>' with a clearance in the direction of the longitudinal axis L1 of the positioning pin <NUM>. Therefore, no static loads in the direction of the longitudinal axis L1 are applied to the inverter busbars <NUM>, <NUM>', <NUM>" via the carrier <NUM> by connecting the intermediate busbars <NUM>, <NUM>', <NUM>" with the motor connectors <NUM>, <NUM>', <NUM>".

The carrier <NUM> further includes two fixation portions <NUM>, <NUM>' each including an insert <NUM>, <NUM>'. The inserts <NUM>, <NUM>' comprise holes <NUM>, <NUM>' through which third fastening elements in the form of third screws <NUM>, <NUM>' extend. The third screws <NUM>, <NUM>' are accommodated in threaded bores of the housing <NUM>. Hereby, the carrier <NUM> is secured to the housing <NUM> reducing vibrations induced from any source of the drive unit <NUM>. The threaded bores of the housing <NUM> are located in the part of the housing <NUM> cut out in <FIG> and <FIG>.

The holes <NUM>, <NUM>' have an elongated shape extending parallel to the longitudinal axis L1 of the positioning pin <NUM> in the present embodiment. However, all shapes of the holes <NUM> are conceivable that realise a clearance in a direction parallel to the longitudinal axis L1 of the positioning pin <NUM> between the holes <NUM>, <NUM>' and the third screws <NUM>, <NUM>'.

The connector assembly <NUM> and the motor <NUM> are covered by a housing cover connected to the housing <NUM> to protect the electrical connection from environmental influences. For the sake of transparency the housing cover is not depicted in the <FIG>.

Claim 1:
Connector assembly for electrically connecting an inverter busbar to an electrical connector of an electric motor of a drive unit, comprising:
a carrier (<NUM>) having a hole (<NUM>, <NUM>'),
an intermediate busbar (<NUM>, <NUM>', <NUM>") comprising a first terminal (<NUM>, <NUM>', <NUM>") with a hole (<NUM>, <NUM>', <NUM>"),
a first fastening element (<NUM>, <NUM>', <NUM>") extending through the hole (<NUM>, <NUM>', <NUM>") of the first terminal (<NUM>, <NUM>', <NUM>"), and
a third fastening element (<NUM>, <NUM>'),
wherein the intermediate busbar (<NUM>, <NUM>', <NUM>") is mounted to the carrier (<NUM>) and the intermediate busbar (<NUM>, <NUM>', <NUM>") is connectable to the inverter busbar (<NUM>, <NUM>', <NUM>") by the first fastening element (<NUM>, <NUM>', <NUM>"),
wherein the carrier (<NUM>) is connectable to the housing (<NUM>) of the drive unit (<NUM>) by the third fastening element (<NUM>, <NUM>') extending through the hole (<NUM>, <NUM>') of the carrier (<NUM>),
characterized in
that the carrier (<NUM>) comprises a positioning pin (<NUM>) defining a longitudinal axis (L1), said positioning pin (<NUM>) being adapted to be accommodated in a receptacle of a housing (<NUM>) of the drive unit (<NUM>) such that the carrier (<NUM>) is axially slidable in the direction of the longitudinal axis (L1);
that the first fastening element (<NUM>, <NUM>', <NUM>") is arranged within the hole (<NUM>, <NUM>', <NUM>") of the first terminal (<NUM>, <NUM>', <NUM>") with a radial clearance relative to the longitudinal axis (L1) of the positioning pin (<NUM>) and
that the third fastening element (<NUM>, <NUM>') is arranged within the hole (<NUM>, <NUM>') of the carrier (<NUM>) with a clearance in a direction parallel to the longitudinal axis (L1) of the positioning pin (<NUM>).