DE10156586A1 - Electric motor actuator drive e.g. for vehicle turbocharger, has drive unit that interacts with actuation element and has electronically commutated electric motor(s) in form of modular permanent magnet machine - Google Patents

Abstract

The actuator drive has a drive unit that interacts with an actuation element and contains at least one electronically commutated electric motor (1) in the form of a modular permanent magnet machine. The actuator drive can be connected to a turbocharger, especially to vary its turbine geometry or its flow geometry

Description

The invention relates to an electromotive actuator for driving one, in particular included by an internal combustion engine of a motor vehicle and / or with this in Operatively connected first system component of the motor vehicle, such as a turbocharger or the like, the actuator being operatively connected to an actuator has a stationary drive unit which has at least one electronically commutated electric motor includes.

A generic electromotive actuator is known from DE 196 11 910 A1, which discloses an electromechanical braking device. Be in this braking device in addition to a disc brake with one brake disc and two brake pads two electronically commutated motors are used, whose rotary movements by means of a gear superimposed and converted into a linear movement. The movement so forced causes the two brake pads to be pressed against the brake disc. adversely in this braking device is that the transmission must have a high gear ratio to to be able to achieve sufficient positioning accuracy of the brake pads, since the step size the motors are relatively large. This results in the braking device two Motors must have to ensure sufficient dynamics. Furthermore, the Actuator designed so that if both electric motors fail, the brake pads move compared to the brake disc is not possible.

An electric high torque motor is known from DE 198 56 647 A1. This Electric motor is in the form of a polyphase permanent magnet synchronous machine (PPSM) that is also referred to as a modular permanent magnet machine (MDM), d. H. this Electronically commutated electric motor has an unequal number of poles in the stator and Rotor on. The motor disclosed in this document has a hollow cylindrical rotor made of soft iron, which is covered on both sides with permanent magnets and coaxial between an outer stator and an inner stator arranged and with one in Machine housing mounted shaft is rotatably connected. A disadvantage of this high torque motor however, that it is structurally complex and thus associated with high manufacturing costs.

The object of the present invention is therefore the generic electromotive To further develop the actuator in such a way that the disadvantages of the prior art are overcome are, in particular for use in a motor vehicle with precise drive simultaneous high dynamics.

According to the invention, this object is achieved in that the electronically commutated Electric motor is constructed in the form of a modular permanent magnet machine.

It can be provided according to the invention that the electromotive actuator means of the actuator, which is preferably in the form of an operative connection with a drive lever standing, rotatable drive rod is executable with the turbocharger, in particular for Adjustment of the turbine or flow geometry of the turbocharger using the electromotive actuator, is connectable.

It is further proposed according to the invention that at least one shaft of the drive unit, in particular via a transmission or directly, can be connected to the actuator.

The invention also proposes that the electronically commutated electric motor can be constructed as an inner rotor, preferably a core acting as a rotor with the shaft the drive unit can be connected, and a pot surrounding the core at least partially as Stator works.

An alternative embodiment according to the invention is characterized in that the electronically commutated electric motor can be constructed as an external rotor, preferably one acting as a rotor and at least partially surrounding a core of the electric motor Pot can be connected to at least one shaft of the drive unit and the core as a stator acts.

In the two aforementioned embodiments it can be provided that the pot or the core at least partially comprises or carries a magnetizable material, preferably via an applied to at least one surface of the pot or core including magnetizable material, such as in the form of at least one ferritic filler Carrier material, such as in the form of a plastic, and first poles of the pot or Core can be formed by locally magnetizing this material.

Alternatively, it can be provided according to the invention that the pot or the core Permanent magnet includes or carries, and first poles of the pot or the core by permanent magnets can be formed.

According to the invention it can be provided that the core or the pot with Connected windings that form second poles.

A further development of the actuator according to the invention is characterized by a first control, regulating and / or diagnostic unit with the drive unit, a second with at least a second system component of the motor vehicle, such as the electronics unit the internal combustion engine, a braking device or the like, connectable control, Control and / or diagnostic unit and / or at least one with the actuator in Actively connected sensor can be connected to determine the position of the actuator.

It can be provided that the connection or connections between the first Control, regulation and / or diagnostic unit, the second control, regulation and / or Diagnostic unit, the first system component, the second system component and / or the sensor can be produced by means of at least one electronic bus system.

According to the invention, it can further be provided that the sensor is inductive, capacitive, works magnetically, optoelectronic and / or contactless.

With the invention it is also proposed that the electric motor actuator Housing comprises, the housing at least partially made of a heat-resistant material, in particular comprising a ceramic, a metal, a plastic and / or the like, can be produced.

According to the electromotive actuator can be characterized in that the actuator if the drive unit fails by means of a positioning device, preferably automatically, can be moved into an emergency position.

It can be provided that the positioning device at least one first and one spring element having a second end, preferably in the form of a spiral, screw, and / or cylindrical spring.

A preferred embodiment can be characterized in that the first or second end of the spring element relative to the actuator and the second or first end of the Spring element can be fixed relative to the housing, whereby when the actuator moves the emergency position in a first direction of movement one of the first direction of movement opposite first spring force and / or when the actuator moves from the emergency position in a second movement direction that differs from the first movement direction a second spring force opposite to the second direction of movement can be generated.

This is a particularly advantageous embodiment of the invention characterized in that an attack of the first and / or the second end of the, preferably biased, Spring element, in particular by means of one with two housing shells of the housing connected pin, can be generated on the housing.

The invention proposes that the positioning device a first and comprises second driver device connected to the actuator, in particular the first and second driver device are executed in one.

Here is a particularly advantageous embodiment of the electromotive actuator characterized in that when the actuator moves from the emergency position into a first Direction of movement the first driver device to 4 m construction of one of the first Direction of movement opposite, first spring force attack at the first end of the finds at least one spring element, and / or when the actuator moves from the emergency position in a second movement direction that differs from the first movement direction the second driver device for establishing one of the second direction of movement opposite second spring force attack at the second end of at least one Finds spring element.

Alternatively, it can be provided that the first or second end of the at least one Spring element can be fixed in a rigid attack relative to the housing, and when the Actuator from the emergency position in a first direction of movement, the first driver device for building up a first spring force opposite to the first direction of movement Attack on the non-fixable end of the at least one spring element takes place, and / or at least when the actuator moves from the emergency position into one of the first Direction of movement distinguishing, second direction of movement the second Driver device for building a second direction opposite to the second direction of movement Spring force attack takes place on the non-fixable end of the at least one spring element.

This is an advantageous further development of the actuator according to the invention characterized in that the first and / or the second spring force are adjustable, in particular both Spring forces are of different sizes.

Finally, the invention proposes that the actuator, preferably by means of between the actuator and with the spring element at least partially in operative connection standing support disks arranged bearings, such as slide or needle bearings, in is substantially free of friction relative to the spring element.

The invention is therefore based on the surprising finding that an electromotive Actuator for driving a system component of a motor vehicle can be executed in this way can that a precise drive with high dynamics is possible by a Electric motor of a drive unit of the actuator as a modular permanent magnet machine (MDM) is executed, d. H. that the motor has an unequal number of poles in the rotor and stator having. This structure of the electric motor allows a smaller step size when operating the Motor, whereby a gearbox to achieve the same positioning accuracy of the actuator with a lower translation is sufficient. This leads to a lower moment of inertia the actuator, which generally increases quadratically with the gear ratio, and thus to a higher dynamic of the actuator with constant accuracy of the Actuator. Furthermore, there is no longer a compromise between when designing the actuator a small, high-revving engine with a large gear ratio and a large, high torque motor with a small ratio, because the special type of MDMs has the advantage of a very large torque in a small space.

Other features and advantages of the invention will appear from the following Description, in the preferred embodiments of the invention by way of example with reference to schematic drawings are explained. It shows:

FIG. 1a is a longitudinal sectional view of a usable in an inventive actuator electric motor;

FIG. 1b is a cross-sectional view of another usable in an inventive actuator electric motor;

Fig. 2 is an exploded view of an electromotive actuator according to the invention;

Fig. 3 shows the electric motor driven actuator of Figure 2 in the closed state. and

Fig. 4 is a longitudinal sectional view of the electromotive actuator according to the invention of FIG. 3.

In Fig. 1a, an electric motor 1 is shown , which can be used as a drive for an electromotive actuator according to the invention. The electric motor 1 comprises a core 3 and a pot 5 and is designed as an external rotor. I.e. the core 3 acts as a stator and is fastened via an opening 7 within an actuator according to the invention, while the pot 5 serves as a rotor and is firmly connected to a shaft 9 . The shaft 9 is supported in the core 3 via ball bearings 11 and a sleeve 12 . According to the invention, the electric motor 1 is constructed as a modular permanent magnet machine (MDM), and therefore the number of poles, which are present in the core 3 in the form of windings 13 on supports 14, different to the number of poles of the cup 5, which S in a aufmagnetisierbaren material 1 which is located on the inner wall of the pot 5, is formed. The use of the material 15 instead of permanent magnets fixed in the pot 5 offers the advantage that the desired ratio of stator to rotor poles can be set in a simple manner during the production of the electric motor 1 by magnetizing the material 15 in the desired manner.

In Fig. 1b shows a further embodiment of an electric motor 20 is shown which can be used in the inventive actuator. In contrast to the electric motor 1 shown in Fig. 1a, 21 permanent magnets are arranged in the electric motor 20 on the inside of a pot acting as a rotor such that a total of fourteen poles 22 are formed. For illustration, two poles 22 are identified as S for the south pole and N for the north pole. A star-shaped core 23 is located inside the pot 21 . The core 23 comprises a total of twelve arms 24 . Windings 25 are arranged on each of these arms 24 , only two windings 25 being shown in FIG. 1b for reasons of clarity. Due to this arrangement, the electric motor 20 has twelve stator poles and fourteen rotor poles.

FIG. 2 shows an exploded view of an actuator 30 according to the invention. An electric motor 32 is used as the drive unit in the actuator 30 , which is designed as an MDM, but in contrast to the electric motor 1 shown in FIG. 1a, in the form of an inner rotor.

The actuator 30 comprises two housing shells 34 and 36 , which consist of a heat-resistant ceramic, so that the actuator 30 high temperatures, for. B. up to 150 ° C, can withstand and can therefore be used in high temperature areas of a motor vehicle. The lower housing shell 34 in FIG. 2 has a recess 38 for receiving the electric motor 32 and an opening 40 for passing through a drive rod 42 . The drive rod 42 is also supported via a needle bearing 44 against the housing 34 , 36 . A first disk 46 , which comprises a tooth element 48 and a first driver 50 , is fixedly connected to the drive rod 42 . In Fig. 2 above the first disc 46 , a first support disc 52 is arranged, which is mounted on the drive rod 42 via a further needle bearing 54 . A spring element in the form of a spiral spring 60 is arranged between the first support disk 52 and a second support disk 56 , which is mounted on the drive rod 42 via yet another needle bearing 58 . In Fig. 2 above the second support disc 56 , a second disc 62 , which is fixedly connected to the drive rod 42 , is arranged. The second disk 62 has a second driver 64 . The drive rod 42 passing through the lower housing shell 34 is received in a recess 66 of the upper housing shell 36 in FIG. 2. The drive rod 42 also has a groove 68 , by means of which it is mounted relative to the lower housing shell 34 .

In the interior of the housing 34 , 36 of the actuator 30 there is also an intermediate wheel 70 which is mounted on a pin 72 which is arranged in an opening 74 in the lower housing shell 34 . A first tooth element 76 located on the edge of the intermediate wheel 70 engages in a pinion 78 which is arranged on a shaft 80 of the electric motor 32 . Furthermore, a second tooth element 82 arranged on the intermediate wheel 70 engages in the tooth element 48 of the disk 46 . A pin 84 is fastened at its first end in a recess (not shown) of the lower housing shell 34 in FIG. 2 and at its second end in a recess 86 in the upper housing shell 36 in FIG. 2.

As can be easily recognized by the person skilled in the art, the needle bearings 44 , 54 , 58 can be replaced by other slide bearings which enable an essentially frictionless bearing.

FIG. 3 shows the electromotive actuator 30 of FIG. 2 in the closed form of its two housing shells 34 and 36 . The reference numerals correspond to those in FIG. 2.

Fig. 4 shows a longitudinal sectional view of the electromotive actuator 30 of Fig. 3. The reference numerals of Fig. 4 correspond to those in Figs. 2 and 3. As can be seen from Fig. 4, the first and second disks 46 and 62 are fixed to the drive rod 42 is connected, while the first and second support plate 52 are mounted 56 via the needle bearings 54 and 58 on the drive rod 42nd Furthermore, the two support disks 52 and 56 are shaped such that the two outer turns of the coil spring 60 rest on first surface areas 52 a and 56 a of the support disks 52 and 56, respectively. The contour of the two support disks 52 and 56 also has a shape such that the outer radius of the support disks 52 and 56 in second surface areas 52 b and 56 b is smaller than the outer radius in the first surface areas 52 a and 56 a. It is thereby achieved that the turns in the second surface areas 52 b and 56 b of the support disks 52 and 56 do not rest in the emergency position of the drive rod 42 shown in FIG. 4. Only when the drive rod 42 moves from the emergency position does the radius of the central windings of the spiral spring 60 decrease and finally the central windings (not shown) also rest on the second surface regions 52 b and 56 b.

As can also be seen from FIG. 4, the drive rod 42 is mounted at its upper end in FIG. 4 in the region of the recess 66 of the upper housing shell 36 and against a displacement along its longitudinal axis via a cylindrical pin 92 , which is in the groove 68 of the drive rod 42 engages, secured. A drive lever 94 is arranged at the lower end of the drive rod 42 in FIG. 4. This drive lever 94 makes it possible to connect the electromotive actuator 30 in particular to a turbocharger (not shown) of an internal combustion engine of a motor vehicle. By rotating the drive lever 94 by means of the electromotive actuator 30 , it is thus possible to adjust the turbine or flow geometry of this turbocharger. Especially in this application, the provision of an emergency position leads to increased operational safety of the internal combustion engine. This ensures that the turbine geometry of the turbocharger is moved into a position in the event of failure of the drive unit of the electromotive actuator 30 , in particular the electric motor 32 , which enables trouble-free, safe and environmentally friendly operation of the internal combustion engine in a wide power range. If the turbocharger were to remain in a different position regardless of the load situation of the internal combustion engine, continued operation of the internal combustion engine could be hindered or even impossible or the internal combustion engine would have an increased emission output.

The electromotive actuator 30 of FIGS. 2 to 4 can be operated as follows:
The electromotive actuator 30 can be mounted in a motor vehicle and comprises a first control or diagnostic unit, not shown, which is preferably connected to further components of the motor vehicle. This connection between the actuator 30 and the motor vehicle is made via an electronic bus system, not shown, which enables the actuator 30 commands to drive a component of the motor vehicle to which the actuator 30 is connected, such as. B. the turbocharger. Furthermore, the first control or diagnostic unit enables the actuator 30 to output data about its operating state. This data can in particular be transmitted to a second control or diagnostic unit (not shown) within the motor vehicle and can be used in a known manner during maintenance of the motor vehicle to query operating states or to enable error detection of components of the motor vehicle. Furthermore, the first control or diagnostic unit is connected to a sensor, not shown, which enables the position of the drive rod 42 to be determined.

If the first control or diagnostic unit receives a command to change the steep position of the actuator 30 , the electric motor 32 is actuated to drive the shaft 80 and the pinion 78 located thereon. A corresponding rotation of the shaft 80 and the pinion 78 is transmitted to the idler gear 70 via the tooth element 76 . The rotation of the intermediate wheel 70 is then transmitted via the tooth element 82 to the tooth element 48 and thus to the disk 46 . Since the disk 46 is fixedly connected to the drive rod 42 , the rotation of the shaft 80 of the electric motor 32 finally leads to a rotation of the drive rod 42 .

The electric motor 32 is designed according to the invention as an MDM, and therefore the transmission ratio between the rotation of the pinion 78 and the rotation of the disk 46 and thus the drive rod 42 can be selected to be relatively small. The reason for this is that the step size of an MDM is smaller than that of a conventional electric motor. The gear ratio can thus be selected to be relatively small in order to achieve a specific step size when the drive rod 42 rotates. This transmission ratio is also positive for the dynamic behavior of the electromotive actuator 30 , since the moment of inertia generally increases quadratically with the transmission ratio of a transmission.

The electromotive actuator 30 also has a positioning device which, if the electric motor 32 fails, ensures that the drive rod 42 moves into a predefined emergency position. This positioning device is formed by the support disks 52 , 56 , the spring element in the form of the spiral spring 60 , the pin 84 and the drivers 50 , 64 .

The coil spring 60 is designed such that a first end 88 of the coil spring 60 bears against a first side of the pin 84 , while a second end 90 of the coil spring 60 bears against the second side of the pin 84 when the electromotive actuator 30 is in the emergency position located. If the drive rod 42 rotates in a first direction of rotation a, counterclockwise in FIG. 2, the first driver 50 engages the first end 88 of the spiral spring 60 . Due to the rigid connection of the drive rod 42 to the disk 46 , a further rotation of the drive rod 42 , that is to say after the first driver 50 engages the spiral spring 60 , leads to a deflection of the first end 88 of the spiral spring 60 , so that the drive rod rotates by one 42 a spring force opposite to the direction of rotation a is generated. On the other hand, when the drive rod 42 is rotated in a second direction of rotation b, clockwise in FIG. 2, the second driver 64 arranged on the disk 62 is engaged at the second end 90 of the coil spring 60 and finally leads to the drive rod 42 when the drive rod 42 is rotated further Direction of rotation b, also to build up a spring force opposite to direction of rotation b.

If the electric motor 32 fails , the spring force stored in the spiral spring 60 causes a restoring torque. This restoring moment causes the disks 46 and 62 to move via the drivers 50 and 64 and thus the drive rod 42 into the emergency position. This movement is transmitted to the shaft 80 of the electric motor 32 via the tooth element 48 , the intermediate gear 70 and the pinion 78 . With this reset, the use of an MDM as an electric motor 32 also has a positive effect. Due to the lower required gear ratio and the associated lower moment of inertia, the return movement is countered by a lower counterforce. It also has a positive effect that an MDM has a lower cogging torque than a comparable normal electric motor. Thus, the use of an electric motor 32 in the form of an MDM makes it easier to return the drive rod 42 to the emergency position.

By using an MDM, the electromotive actuator 30 combines two opposing requirements, namely that on the one hand a high dynamic should be present when the actuator 30 is actively moving and on the other hand there should be a small counter torque when the actuator 30 is moving passively. Furthermore, by using an MDM, the electromotive actuator offers the advantages that it can meet the service life requirements in the commercial vehicle sector (> 20,000 hours) and can be made very compact, so that a highly dynamic actuator can be realized in the smallest of spaces.

The features of the invention disclosed in the above description, in the drawings and in the claims can be essential both individually and in any combination for realizing the invention in its various embodiments. Reference Signs List 1 electric motor
3 core
5 pot
7 opening
9 wave
11 ball bearings
12 sleeve
13 winding
14 brackets
15 magnetizable material
20 electric motor
21 pot
22 pin
23 core
24 arm
25 winding
30 actuator
32 electric motor
34 housing shell
36 housing shell
38 recess
40 opening
42 drive rod
44 needle bearings
46 disc
48 tooth element
50 first driver
52 support disc
52 a, 52 b surface area
54 needle bearings
56 support disc
56 a, 56 b surface area
58 needle bearings
60 coil spring
62 disc
64 second driver
66 recess
68 groove
70 idler gear
72 pen
74 opening
76 tooth element
78 sprockets
80 wave
82 tooth element
84 pen
86 recess
88 first end
90 second end
92 cylinder pin
94 drive lever
a first direction of rotation
b second direction of rotation
N north pole
S South Pole

Claims (21)

1. Electromotive actuator ( 30 ) for driving a first system component of the motor vehicle, which is particularly comprised by an internal combustion engine of a motor vehicle and / or is operatively connected thereto, such as a turbocharger or the like, the actuator ( 30 ) having an actuator ( 42 ) has an operatively connected drive unit which comprises at least one electronically commutated electric motor ( 1 , 20 , 32 ), characterized in that the electronically commutated electric motor ( 1 , 20 , 32 ) is constructed in the form of a modular permanent magnet machine. 2. Electromotive actuator according to claim 1, characterized in that the electromotive actuator ( 30 ) by means of the actuator, which is preferably in the form of a with a drive lever ( 94 ) in operative connection, rotatable drive rod ( 42 ) with the turbocharger, in particular to adjust the turbine or flow geometry of the turbocharger by means of the electromotive actuator ( 30 ). 3. Electromotive actuator according to claim 1 or 2, characterized in that at least one shaft ( 9 , 80 ) of the drive unit, in particular via a gear (46, 48, 70, 76, 78, 82) or directly with the actuator ( 42 ) is connectable. 4. Electromotive actuator according to one of the preceding claims, characterized in that the electronically commutated electric motor ( 32 ) can be constructed as an internal rotor, preferably a core acting as a rotor can be connected to the shaft ( 80 ) of the drive unit, and at least partially the core surrounding pot acts as a stator. 5. Electromotive actuator according to one of claims 1 to 3, characterized in that the electronically commutated electric motor ( 1 , 20 ) can be constructed as an external rotor, preferably one acting as a rotor and a core ( 3 , 23 ) of the electric motor ( 1 , 20th ) at least partially surrounding pot ( 5 , 21 ) can be connected to at least one shaft ( 9 ) of the drive unit and the core ( 3 , 23 ) acts as a stator. 6. Electromotive actuator according to claim 4 or 5, characterized in that the pot ( 5 ) or the core at least partially comprises or carries a magnetizable material ( 15 ), preferably applied to at least one surface of the pot ( 21 ) or core , which comprises magnetizable material ( 15 ), such as in the form of at least one ferritic filler, containing carrier material, such as in the form of a plastic, and first poles of the pot or the core can be formed by local magnetization of this material ( 15 ). 7. Electromotive actuator according to claim 4 or 5, characterized in that the pot ( 21 ) or the core comprises or carries permanent magnets, and first poles of the pot ( 21 ) or the core can be formed by the permanent magnets. 8. Electromotive actuator according to one of claims 4 to 7, characterized in that the core ( 3 , 23 ) or the pot is firmly connected to windings ( 13 , 25 ) which form the second poles. 9. Electromotive actuator according to one of the preceding claims, characterized by a first control, regulating and / or diagnostic unit, with the drive unit, ( 1 , 20 , 32 ) a second with at least a second system component of the motor vehicle, such as the electronics unit Internal combustion engine, a braking device or the like, connectable control, regulating and / or diagnostic unit and / or at least one sensor operatively connected to the actuator ( 42 ) for determining the position of the actuator ( 42 ). 10. Electromotive actuator according to claim 9, characterized in that at least the connection or connections between the first control, rule and / or diagnostic unit, the second control, regulation and / or diagnostic unit, the first system component, the second system component and / or the sensor at least one electronic bus system can be produced. 11. Electromotive actuator according to claim 9 or 10, characterized in that the sensor is inductive, capacitive, magnetic, optoelectronic and / or contactless is working. 12. Electromotive actuator according to one of the preceding claims, characterized in that the electromotive actuator ( 30 ) comprises a housing ( 34 , 36 ), the housing at least partially made of a heat-resistant material, in particular comprising a ceramic, a metal, a plastic and / or the like, can be produced. 13. Electromotive actuator according to one of the preceding claims, characterized in that the actuator ( 42 ) in the event of failure of the drive unit ( 1 , 20 , 32 ) by means of a positioning device ( 50 , 52 , 56 , 60 , 64 ), preferably automatically, in one Emergency position is movable. 14. Electromotive actuator according to claim 13, characterized in that the positioning device has at least a first ( 88 ) and a second end ( 90 ) having spring element, preferably in the form of a spiral ( 60 ), helical, and / or cylindrical spring , 15. Electromotive actuator according to claim 14, characterized in that the first ( 88 ) or second end ( 90 ) of the spring element ( 60 ) relative to the actuator ( 42 ) and the second ( 90 ) or first end ( 88 ) of the spring element ( 60 ) can be fixed relative to the housing ( 34 , 36 ), with a first spring force opposite the first direction of movement (a) when the actuator ( 42 ) moves from the emergency position in a first direction of movement (a) and / or when the actuator ( 42 ) a second spring force opposite to the second movement direction (b) can be generated from the emergency position in a second movement direction (b) which differs from the first movement direction (a). 16. Electromotive actuator according to claim 14 or 15, characterized in that an attack of the first ( 88 ) and / or the second end ( 90 ) of the, preferably biased, spring element ( 60 ), in particular by means of one with two housing shells ( 34 , 36th ) of the housing connected pin ( 84 ) on the housing ( 34 , 36 ) can be generated. 17. Electromotive actuator according to one of claims 14 to 16, characterized in that the positioning device comprises a first and second driver device ( 50 , 64 ) connected to the actuator, in particular the first ( 50 ) and second driver device ( 64 ) executed in one are. 18. Electromotive actuator according to claim 17, characterized in that when moving the actuator ( 42 ) from the emergency position in a direction of movement (a), the first driver device ( 50 ) to build up a first direction of movement (a) opposite, first spring force attack on the finds the first end ( 88 ) of the at least one spring element ( 60 ), and / or when the actuator ( 42 ) moves from the emergency position in a second movement direction (b) that differs from the first movement direction (a), the second driver device ( 64 ) for Structure of a second spring force opposite to the second direction of movement (b) engages the second end ( 90 ) of the at least one spring element ( 60 ). 19. Electromotive actuator according to claim 17, characterized in that the first ( 88 ) or second end ( 90 ) of the at least one spring element ( 60 ) can be fixed in a rigid attack relative to the housing ( 34 , 36 ), and upon movement of the actuator ( 42 ) from the emergency position in a first direction of movement (a) the first driver device ( 50 ) for building up a first spring force opposite to the first direction of movement (a) engages the non-fixable end ( 90 , 88 ) of the at least one spring element ( 60 ), and / or at least when the actuator ( 42 ) moves from the emergency position in a second movement direction (b) that differs from the first movement direction (a), the second driver device ( 64 ) for building up a second spring force attack opposite to the second movement direction (b) at the non-fixable end ( 90 , 88 ) of the at least one spring element ( 60 ). 20. Electromotive actuator according to one of claims 15 to 19, characterized characterized in that the first and / or the second spring force are adjustable, in particular both spring forces are of different sizes. 21. Electromotive actuator according to one of claims 14 to 20, characterized in that the actuator ( 42 ), preferably by means of between the actuator ( 42 ) and with the spring element ( 60 ) at least partially operatively connected support disks ( 52 , 56 ) arranged bearings , such as sliding or needle bearings ( 54 , 58 ), can be moved essentially without friction relative to the spring element ( 60 ).