Switchable bearing

Abstract

Switchable bearing (2), in particular a switchable, hydraulically damping bearing (2), especially as an engine mount (2) for a motor vehicle, with a closing element (20) which is designed to at least partially close and open a channel (18), and a switching actuator (30) which is controllably connected to the closing element (20), wherein the switching actuator (30) comprises the following components: - at least one permanent magnet (38), - at least one first ferromagnetic element (40), - at least one second ferromagnetic element (42), and - at least one electrically conductive coil (44) through which a current flows in the current-carrying state of the switching actuator (30), wherein the aforementioned components of the switching actuator (30) are arranged to be movable relative to each other in such a way that in a first state of the switching actuator (30) the closing element (20) can be positioned in a first position in the longitudinal direction (Z) of the switching actuator (30) and in a second state of the switching actuator (30) the closing element (20) can be positioned in a second position in the longitudinal direction (Z) of the switching actuator (30), wherein the permanent magnet (38) and / or the first ferromagnetic element (40) and / or the second ferromagnetic element (42) is / are designed such that, in the unenergized state of the coil (44), unequal magnetic forces are exerted in the longitudinal direction (Z) of the switching actuator (30), characterized by the fact that the first ferromagnetic element (40) and / or the second ferromagnetic element (42) has / have at least one recess (40a, 40b, 42a, 42b) perpendicular to the longitudinal direction (Z) of the switching actuator (30).

Description

[0001] The present invention relates to a switchable bearing according to the preamble of claim 1, a motor with such a bearing according to claim 14 and a motor vehicle with such a motor according to claim 15.

[0002] Switchable engine mounts are a well-known type of engine mount for motor vehicles. Compared to conventional engine mounts, switchable engine mounts offer the advantage of being able to switch between two different states. This allows for the implementation of two different stiffness and damping characteristics, for example. The two states typically used are "driving" and "idling."

[0003] For example, hydraulically damped engine mounts are used as switchable engine mounts. In this case, a channel connecting the working chamber and the compensation chamber can be opened and closed at will. Alternatively, a switchable mount can also have a channel for venting an air chamber below the decoupling membrane that can be opened and closed at will. In both cases, opening or closing this channel allows for the selection of two different stiffness and damping characteristics of the engine mount, thus enabling the engine mount to be switched between "soft" and "hard" settings.

[0004] Such a switching function between two states can be implemented in a switchable bearing, for example, via an electromagnetically operating actuator, in which the magnetic flux in the actuator can be closed via a magnetically conductive plate by energizing a coil, thereby allowing this plate to be moved to close the aforementioned channel.

[0005] A disadvantage of this method is that the plate can only be moved in one direction. Therefore, this type of actuator always requires a mechanical return spring to perform the opposite movement. This can lead to the further disadvantage that such electromagnetic actuators, due to their coils which must perform all the work of moving them against the mechanical return spring, can be relatively large.

[0006] Alternatively, for example, an actuator for a switchable, hydraulically damped bearing is known from DE 10 2010 060 886 A1, which, in addition to the electromagnetic coil system, also has a permanent magnet whose permanent magnetic field can cause the channel to be closed by a plate or similar element. A first ferromagnetic body, together with the coil and the permanent magnet, is arranged longitudinally along the bearing below the plate, which is connected to a second ferromagnetic body. When the coil is de-energized, the magnetic field of the permanent magnet closes across the two ferromagnetic bodies, so that the second ferromagnetic body, along with the plate, is attracted longitudinally along the bearing to the first ferromagnetic body. In this state, the channel is closed.

[0007] To open the channel, the actuator coil can be energized in such a way that the permanent magnet field is completely compensated, allowing the plate to move freely away from the permanent magnet along the longitudinal axis of the bearing. When the current to the actuator coil is interrupted, the permanent magnet's magnetic field closes again via the two ferromagnetic bodies, causing the second ferromagnetic body to be attracted to the first ferromagnetic body along the longitudinal axis of the bearing, and the channel is closed again by removing the plate.

[0008] An advantage of this type of actuator is that it does not require a mechanical return spring. This allows for a more compact actuator design.

[0009] A disadvantage of this type of actuator, however, is its high sensitivity to external influences such as voltage fluctuations, temperature changes, etc., which can make it unsuitable for series production. In particular, there is a risk of overcompensation, meaning that the coil can generate such a strong electromagnetic field that it not only compensates for the magnetic field of the permanent magnet but also creates an even stronger electromagnetic field. This electromagnetic field can attract the second ferromagnetic body and its plate in the same way as the permanent magnet itself would, causing the channel to remain open in both switching states.

[0010] It is generally advantageous with such switchable, hydraulically damped bearings to design the actuator of the switchable motor mount in such a way that, when idling, the channel can be opened by energizing the actuator, and when driving, the channel closes automatically due to the lack of energizing the actuator. This also serves as a safety function to ensure that sufficient damping is still available for driving in the event of actuator failure or a loss of power supply.

[0011] It is also known to use pneumatic actuators for switchable motor mounts. However, a disadvantage here is that providing compressed air or a vacuum can be very complex and expensive.

[0012] DE 10 2015 223 396 A1 discloses a switchable bearing, in particular a switchable hydraulically damping bearing, especially as an engine mount for a motor vehicle, with a closing element configured to at least partially close and open a channel, and a switching actuator that is controllably connected to the closing element, wherein the switching actuator comprises the following components: at least one permanent magnet, at least one first ferromagnetic element, at least one second ferromagnetic element, and at least one electrically conductive coil through which a current flows when the switching actuator is in the current-carrying state, wherein the aforementioned components of the switching actuator are arranged to be movable relative to one another.that in a first state of the switching actuator, the closing element can be positioned in a first position in the longitudinal direction of the bearing, and in a second state of the switching actuator, the closing element can be positioned in a second position in the longitudinal direction of the bearing. The switchable bearing is characterized in that the permanent magnet, the two ferromagnetic elements, and the coil are arranged essentially in a plane perpendicular to the longitudinal direction of the bearing.

[0013] DE 10 2005 028 337 A1 discloses a hydraulic bearing with a working chamber and a compensating chamber, which are connected to each other via at least one throttle channel and a bypass channel connected in parallel to it, which can be closed by means of an electromagnetic valve. The throttle channel and the bypass channel, together with the valve, are arranged in a partition plate that separates the chambers. The volumes of the working and compensating chambers, filled with hydraulic fluid, can be alternately changed by compressing and decompressing a rubber component. To avoid a constant power consumption of the bypass circuit, the electromagnetic valve has a linear actuator and a transversely movable slide. The linear actuator consists of a magnetic circuit with an electrically actuated coil and a permanent magnet.In the separating plate, which consists of plastic or non-magnetic metal, at least one plate or pin made of ferromagnetic material is arranged in such a way that it enters the attraction area of ​​the magnetic circuit in at least one of the end positions of the slider.

[0014] One object of the present invention is to provide a switchable bearing of the type described above, such that a channel can be switched as simply as possible. At the same time, the switching function should be robust, i.e., it should avoid excessive sensitivity of the switching function to external influences such as voltage fluctuations, temperature changes, etc., which could lead to overcompensation. In particular, the switching function should be possible with the smallest possible installation space. Furthermore, the switching function should be able to be operated with the least possible electrical power consumption. At the very least, an alternative to known solutions should be provided.

[0015] The object of the invention is achieved by a switchable bearing with the features according to claim 1, a motor with the features according to claim 14, and a motor vehicle with the features according to claim 15. Advantageous embodiments are described in the dependent claims.

[0016] The present invention thus relates to a switchable bearing according to the preamble of claim 1, characterized in that the permanent magnet and / or the first ferromagnetic element and / or the second ferromagnetic element are / are configured such that unequal magnetic forces are exerted in the longitudinal direction of the switching actuator when the coil is de-energized. In other words, by a suitable selection of the geometry, the pole area ratio, and / or the magnetic field derivation, the magnetic field of the permanent magnet between the stationary and the moving components of the switching actuator can be configured such that a resultant force direction is formed when the switching actuator is de-energized. This can preferably be achieved by making the air gap narrower or wider in the region where unequal magnetic forces are to be exerted than in its rest of the path.This can be used so that, in the unpowered state, the switching actuator can move the closing element to a first position. When the switching actuator is powered, a second position of the closing element can be assumed in this second state.

[0017] The advantage here is that the switching actuator can be designed more simply than previously known designs, because the closing element can be switched back and forth between the two states, and thus between the two positions, by switching the current on and off. This eliminates the need for separate control or current supply between, for example, two states or positions, which would require more complex electrical control. Furthermore, for safety reasons, the unpowered state can be selected so that it is assumed in the event of a power failure.

[0018] Furthermore, overcompensation of the permanent magnet's static magnetic field, for example by excessive current to the switching actuator, which could lead to an unintended switching state, can be reliably avoided. This can make the switching actuator significantly less sensitive to external influences.

[0019] The coil must be designed in such a way that the static magnetic field of the permanent magnet can be sufficiently deflected under all boundary conditions such as temperatures, voltages, etc., to ensure switching between the two states of the switching actuator.

[0020] The magnetic flux emanating from the permanent magnet is always guided through the ferromagnetic elements. The magnetic flux can only be redirected by energizing the coil in such a way that the holding force exerted by the magnetic flux can be reduced sufficiently to allow the closing element to move longitudinally along the switching actuator.

[0021] The advantage here is that a mechanical return spring, whose force would have to be overcome to move the closing element in one direction along the longitudinal axis of the switching actuator, can be dispensed with. Instead, a switching function can be achieved by energizing the coil in interaction with the constant magnetic field of the permanent magnet. This is advantageous because it allows for a compact and, in particular, flat design of the actuator and thus also of the bearing, especially in the longitudinal direction of the switching actuator.

[0022] Preferably, the necessary elements of the switching actuator, such as the first and second ferromagnetic elements, the coil, and the permanent magnet, are arranged essentially in a plane perpendicular to the longitudinal direction of the switching actuator, which is preferably the horizontal plane of the bearing. To exert unequal magnetic forces in the longitudinal direction of the switching actuator when the coil is de-energized, at least one of these elements is not mirror-symmetrical to the horizontal plane. The horizontal plane thus forms an intermediate position, allowing the movable component of the switching actuator to move unequally in both directions along the longitudinal direction of the switching actuator.

[0023] An advantage of applying the permanent magnet's forces unevenly is that the switching actuator's force output can be increased. Furthermore, this allows the switching actuator's stroke range to be extended.

[0024] According to one aspect of the present invention, the first ferromagnetic element and / or the second ferromagnetic element has / have at least one recess projecting perpendicular to the longitudinal direction of the switching actuator. In other words, either the first ferromagnetic element or the second ferromagnetic element, or both ferromagnetic elements, form at least one recessed area that projects in the direction of the other ferromagnetic element, thus increasing the air gap between the two ferromagnetic elements in this area. In this way, simple design measures can be used to ensure that unequal magnetic forces can be exerted along the longitudinal direction of the switching actuator when the coil is de-energized.

[0025] According to a further aspect of the present invention, the first ferromagnetic element and / or the second ferromagnetic element has a first recess and a second recess, which are spaced apart from each other in the longitudinal direction of the switching actuator, wherein the two recesses are preferably arranged at the edges of the first ferromagnetic element and / or the second ferromagnetic element in the longitudinal direction of the switching actuator. By spacing the two recesses, which can be arranged on the same ferromagnetic element or on different ferromagnetic elements, the essential area of ​​the respective ferromagnetic element in the longitudinal direction of the switching actuator can be enclosed by the recesses, so that the desired effect on the static magnetic field can be achieved.

[0026] According to a further aspect of the present invention, the step or steps are inclined to the longitudinal direction of the switching actuator and increase in size towards the edge along the longitudinal direction of the switching actuator. In this way, a uniform deflection of the static magnetic field can be achieved. In other words, abrupt deflection can be avoided.

[0027] According to one aspect of the present invention, the first ferromagnetic element is arranged essentially around the second ferromagnetic element, wherein the first ferromagnetic element is stationary and the second ferromagnetic element is movable relative to the first ferromagnetic element in the longitudinal direction of the switching actuator. The second ferromagnetic element can be connected to the closing element, so that the closing or opening function of the switching actuator or the bearing can be performed via the movement of the second ferromagnetic element. By arranging the movable second ferromagnetic element within the stationary first ferromagnetic element, the movement can be achieved in a structurally simple manner.

[0028] According to a further aspect of the present invention, the first ferromagnetic element substantially encloses the coil and / or the permanent magnet, preferably in a C-shape. In this way, the magnetic flux emanating from the permanent magnet and / or the energized coil can be enclosed around them. The C-shaped design allows for a symmetrical construction of the first ferromagnetic element with respect to a plane perpendicular to the longitudinal direction of the switching actuator.

[0029] According to a further aspect of the present invention, the coil substantially encloses the permanent magnet, preferably in a ring-like manner, wherein the coil and the permanent magnet are radially spaced apart from each other, preferably at least partially, by the first ferromagnetic element. This allows the coil and the permanent magnet to be arranged substantially in the same plane perpendicular to the longitudinal direction of the switching actuator. Arranging the coil around the permanent magnet in this way can have the advantage that the magnetic field of the permanent magnet can be effectively influenced or canceled out by the energized coil.

[0030] According to a further aspect of the present invention, an air gap is formed between the coil and the permanent magnet, at least in sections. This allows the magnetic flux of the coil and the permanent magnet to be directed in a controlled manner.

[0031] According to a further aspect of the present invention, the air gap in the longitudinal direction of the switching actuator is asymmetrically designed. In this way, too, simple design measures can ensure that unequal magnetic forces can be exerted in the longitudinal direction of the switching actuator when the coil is de-energized.

[0032] According to a further aspect of the present invention, the second ferromagnetic element is cylindrical in the longitudinal direction of the switching actuator, and the permanent magnet, the coil, and the first ferromagnetic element are annular in shape in the longitudinal direction of the switching actuator. In this way, a cylindrically symmetrical design of the magnetic flux of the energized coil and the permanent magnet can be achieved, so that the movements thereby attainable can be effected almost exclusively in the longitudinal direction of the switching actuator. This avoids forces in directions perpendicular to the longitudinal direction of the switching actuator, which could negatively affect the desired movement, e.g., by tilting or jamming the movable element of the switching actuator.

[0033] According to a further aspect of the present invention, the switchable bearing further comprises a first mechanical limitation of the movement of the second ferromagnetic element in the longitudinal direction of the switching actuator, wherein when the second ferromagnetic element is in contact with the first mechanical limitation, the switching actuator is in the first state, the coil is de-energized and the channel is closed by positioning the closing element in the first position.

[0034] The geometry, pole area ratio, and magnetic field conduction of the switching actuator are designed such that a magnetic force can act on the second ferromagnetic element, causing it to move longitudinally along the switching actuator towards the first mechanical boundary. Simultaneously, the channel and its closing element are designed to allow the channel to be closed by the closing element.

[0035] For this application, the switching actuator requires a so-called negative stiffness or force-displacement characteristic. In this case, the second ferromagnetic element, starting from the plane perpendicular to the longitudinal direction of the switching actuator (its zero position), always experiences a force in the direction of the first mechanical limit, which can generate movement until the second ferromagnetic element reaches the first mechanical limit and the channel is closed.

[0036] The force in the direction of the first mechanical limit is thus exerted via the magnetic field lines of the permanent magnet when the coil is sufficiently weakly energized or not energized at all. This allows the first position of the closing element to be maintained permanently when the coil is de-energized, keeping the channel closed. This fulfills the safety function of securely closing the channel in the event of a power failure. Furthermore, it is advantageous that this state can be maintained without the expenditure of electrical energy, which can result in significant energy savings.

[0037] According to a further aspect of the present invention, the switchable bearing further comprises a second mechanical limitation of the movement of the second ferromagnetic element in the longitudinal direction of the switching actuator, wherein when the second ferromagnetic element is in contact with the second mechanical limitation, the switching actuator is in the second state, the coil is energized and the channel is opened by positioning the closing element in the second position.

[0038] If, starting from a switching actuator in the previously described first state with the channel closed, the channel is to be opened, the second ferromagnetic element must be moved longitudinally along the switching actuator away from the first mechanical limiting element. This can be achieved by energizing the coil in one direction, creating an electromagnetic field around the energized coil and the permanent magnet. This deflects the magnetic field of the permanent magnet in such a way that the second ferromagnetic element can be moved longitudinally along the switching actuator away from the first mechanical limit until it reaches the stop of the second mechanical limit. This opens the channel.

[0039] The second mechanical limit is designed in the longitudinal direction of the switching actuator such that, upon reaching its stop against this limit, the second ferromagnetic element can be positioned approximately in the plane perpendicular to the longitudinal direction of the switching actuator, i.e., at the center of the actuator's height (center position). This position can be considered unstable because, when the coil is de-energized, the magnetic reluctance force of the permanent magnet can move the second ferromagnetic element back towards the first mechanical limit. Therefore, a continuous current supply to the coil may be necessary to keep the second ferromagnetic element in the center position against the second mechanical limit, and thus to keep the channel open.

[0040] If the current to the coil is interrupted again, the magnetic field of the permanent magnet can no longer be dissipated accordingly, and the original magnetic field with negative stiffness is restored. The second ferromagnetic element now moves back towards the first mechanical boundary, and the channel is closed.

[0041] The advantage here is that only one current flow direction needs to be provided when wiring the coil. Furthermore, the switching actuator can assume both states via the current-on and current-off circuit, and the two positions of the closing element can be implemented to open and close the channel. This can significantly reduce the complexity of the coil's wiring.

[0042] The coil must be designed to be sufficiently strong so that the magnetic field of the permanent magnet can be deflected as desired under all boundary conditions, such as voltage, temperature, etc. An advantage over the switching actuator known from DE 10 2010 060 886 A1 is that, with this aspect of the switching actuator according to the invention, overcompensation of the static magnetic field cannot occur, for example, if the current is too high. This is achieved because the energized coil would always exert a resulting force against the stop of the second mechanical limit, i.e., it would prevent any movement towards the first mechanical limit. This would lead to an undesired closure of the channel. An electromagnetic switching actuator according to this aspect of the present invention can therefore be significantly less sensitive to external influences than known switching actuators.

[0043] According to a further aspect of the present invention, a friction element or a sliding element is arranged between the first ferromagnetic element and / or the permanent magnet and the second ferromagnetic element, wherein one side of the friction element or the sliding element is in contact, at least partially, with the first ferromagnetic element and / or the permanent magnet, and the opposite side of the friction element or the sliding element is in contact, at least partially, with the second ferromagnetic element. Whether this contact can be considered friction or sliding depends on the choice of the coefficient of friction or sliding of the contacting sides or surfaces.

[0044] A sliding bearing offers the advantage of reliable guidance of the movable second ferromagnetic element relative to the stationary first ferromagnetic element, while keeping the force required for this relative movement, which can be exerted by energizing the coil, to a minimum. This can help reduce the size of the coil, resulting in a smaller switching actuator.

[0045] A friction bearing offers the advantage of damping the movement of the movable second ferromagnetic element relative to the stationary first ferromagnetic element. This reduces the current required to hold the second ferromagnetic element in its neutral position, both when stopped against the second mechanical limit and in the controlled state, because the friction can counteract the relative movement. Even in the controlled state, this mechanical damping can improve or simplify the control process.

[0046] Furthermore, it is advantageous that the distance between the two ferromagnetic elements or between the permanent magnet and the second ferromagnetic element can be adjusted by means of the friction or sliding bearing.

[0047] The present invention also relates to an engine, in particular for a motor vehicle, with a switchable bearing as described above. In this way, the previously described properties and advantages of the switchable bearing according to the invention can be applied to an engine.

[0048] The present invention also relates to a motor vehicle with an engine as described above. In this way, the previously described properties and advantages of the engine according to the invention can be applied to a motor vehicle.

[0049] Some exemplary embodiments and further advantages of the invention are explained below in connection with the following figures. These show: Fig. 1 a schematic sectional view of a switchable, hydraulically damping engine mount according to the invention in general; Fig. 2 a schematic sectional view of a switching actuator of the motor bearing according to the invention Fig. 1. General; Fig. 3 a schematic section of a switching actuator according to the invention in a first embodiment; Fig. 4 a schematic section of a switching actuator according to the invention in a second embodiment; Fig. 5 a schematic section of a switching actuator according to the invention in a third embodiment; Fig. 6 a schematic section of a switching actuator according to the invention in a fourth embodiment; Fig. 7 a schematic section of a switching actuator according to the invention in a fifth embodiment; Fig. 8 a schematic section of a switching actuator according to the invention in a sixth embodiment; Fig. 9 a schematic section of a switching actuator according to the invention in a seventh embodiment; and Fig. 10 a schematic section of a switching actuator according to the invention in an eighth embodiment.

[0050] Fig. Figure 1 shows a schematic sectional view of a switchable motor mount 2 according to the invention in general, which is designed as a switchable, hydraulically damping motor mount 2. Fig. Figure 2 shows a schematic sectional view of a switching actuator 30 according to the invention for the motor bearing 2 of the Fig. 1. General.

[0051] The engine mount 2 extends essentially in a longitudinal direction Z, which can also be referred to as height Z. The engine mount 2 also extends in a direction Y perpendicular to the longitudinal direction Z, which can also be referred to as width Y. The perpendicular direction Y, together with another direction that is perpendicular to both the longitudinal direction Z and the perpendicular direction Y, forms a plane XY, which can also be referred to as the horizontal plane XY.

[0052] Such engine mounts 2 are known per se, so their basic structure will only be briefly explained here. Only those components of the known engine mount 2 that are relevant to the present invention will be discussed.

[0053] The engine mount 2 is rotationally symmetrical about its longitudinal direction Z or its longitudinal axis Z, which is why the radial direction R extends perpendicularly from the longitudinal direction Z or longitudinal axis Z. The engine mount 2 includes a journal 4 on which the engine of a motor vehicle is suspended (not shown). Furthermore, the engine mount 2 includes a working chamber 6 and a compensating chamber 8, each filled with hydraulic fluid and separated from each other by a partition 10. The partition 10 consists of an upper part 12 and a lower part 14 and includes an annular channel 16, through which the working chamber 6 is connected to the compensating chamber 8 in a manner known per se. In addition, the partition 10 includes a bypass channel 18. A closing element 20 in the form of a disc-shaped diaphragm 20, whose cross-section corresponds to the cross-section of the bypass channel 18, is located in the bypass channel 18.

[0054] The diaphragm 20 is arranged in the partition wall 10 or in the bypass channel 18 such that it is deflectable in the longitudinal direction Z of the bearing 2. The upward movement of the diaphragm 20 in the longitudinal direction Z of the motor bearing 2 (i.e., towards the working chamber 6) is limited by a first closing element stop 22 or diaphragm stop 22 on the upper part 12. Additionally, the downward movement of the diaphragm 20 in the longitudinal direction Z of the motor bearing 2 (i.e., towards the compensation chamber 8) is limited by a second closing element stop 24 or diaphragm stop 24 on the lower part 14. The surface of the diaphragm 20 facing the working chamber 6 is in contact with the hydraulic fluid in the working chamber 6 through the opening 26 in the upper part 12.

[0055] In addition to the components mentioned so far, the motor mount 2 also contains an electromagnetic switching actuator 30, with which the diaphragm 20 can be switched via a connecting element 31. The switching actuator 30 is arranged in the longitudinal direction Z of the motor mount 2 below the diaphragm 20 on the side of the partition 10 facing away from the working chamber 6. The longitudinal direction Z of the switching actuator 30 corresponds to the longitudinal direction Z of the motor mount 2. The switching actuator 30 is designed such that, in the de-energized state, it exerts a magnetic holding force on the diaphragm 20 via the connecting element 31 and fixes the diaphragm 20 in a rest position. In the case of the Fig. In the motor mount 2 shown, the diaphragm 20 rests in its rest position on the diaphragm stop 24 of the lower part 14 of the partition 10, so that the bypass channel 18 is blocked.

[0056] Furthermore, the switching actuator 30 is designed such that, in the current-carrying state, it reduces the magnetic holding force to such an extent that the diaphragm 20 is released for movement in the longitudinal direction Z of the switching actuator 30 or of the motor bearing 2. The diaphragm 20 can then move freely in the longitudinal direction Z of the switching actuator 30 between the diaphragm stop 22 and the diaphragm stop 24 and release the bypass channel 18.

[0057] In addition to the components mentioned so far, the motor mount 2 includes an annular decoupling membrane 32, which is located between the upper part 12 and the lower part 14 of the partition 10 and encompasses the membrane 20. The upper side of the decoupling membrane 32 is exposed to the hydraulic fluid in the working chamber 6 through a first window 34 in the upper part 12. The lower side of the decoupling membrane 32 is exposed to the hydraulic fluid in the compensation chamber 8 through a second window 36 in the lower part 14.

[0058] The operation of the switchable engine mount 2 is as follows: when vibrations are introduced into the engine mount 2 via the (not shown) engine during normal driving operation, hydraulic fluid is transferred from the working chamber 6 via the annular channel 16 into the compensation chamber 8 (or in the reverse direction). Due to the throttling effect of the annular channel 16, the vibrations introduced into the engine mount 2 are dampened. During the introduction of these vibrations, the diaphragm 20 is fixed in its rest position by means of the switching actuator 30. The bypass channel 18 is then closed, so that damping of the vibrations during normal driving operation can only occur via the annular channel 16.

[0059] For idling vibrations whose frequencies are higher than those occurring during normal driving operation, the annular channel 16 is dynamically closed, preventing hydraulic fluid from flowing back and forth between the working chamber 6 and the compensation chamber 8. Therefore, the bypass channel 18 must be opened during engine idling to dampen these vibrations.

[0060] During the introduction of idling vibrations into the engine mount 2, the switching actuator 30 is therefore switched to the current-carrying state, so that the magnetic holding force of the switching actuator 30 is reduced to such an extent that the diaphragm 20 is released for movement in the longitudinal direction Z of the switching actuator 30 or the engine mount 2. The introduced idling vibrations are then compensated by the movement of the diaphragm 20 in the bypass channel 18, which keeps the volume of the working chamber 6 constant. This is achieved by the diaphragm 20 moving freely up and down in the bypass channel 18. This means that the diaphragm 20 is moved up and down in the longitudinal direction Z of the switching actuator 30 solely by the pressure exerted on it by the hydraulic fluid in the working chamber 6 or in the compensation chamber 8.The movement of the diaphragm 20 in the bypass channel 18 is not influenced by the switching actuator 30 when it is energized. Vibrations with other frequencies introduced into the motor bearing 2 can be compensated for in a known manner using the decoupling diaphragm 32.

[0061] The electromagnetic switching actuator 30 is also rotationally symmetrical about its longitudinal axis Z, which is identical to the longitudinal axis Z of the motor bearing 2. The switching actuator 30 contains a ring-shaped permanent magnet 38, a ring-shaped first ferromagnetic element 40 in the form of a shell 40, and a substantially cylindrical second ferromagnetic element 42 in the form of a ferromagnetic core 42 or ferromagnetic armature 42. Furthermore, the switching actuator 30 contains a ring-shaped electrically conductive coil 44, the current-supplying line to the coil 44 and the current-dissipating line from the coil 44 are not shown.

[0062] The casing 40 is essentially C-shaped and surrounds the coil 44 radially outside, from above, from below, and partially radially inside. Furthermore, the casing 40 surrounds the permanent magnet 38 from above, from below, and partially radially outside. The radially inner side of the coil 44 and the radially outer side of the permanent magnet 38 are partially spaced apart radially by the casing 40. The remaining space between the coil 44 and the permanent magnet 38 is separated by a closed inner air gap 46, which simultaneously interrupts the casing 40 in the longitudinal direction Z of the switching actuator 30. These elements 38, 40, 44 of the switching actuator 30 are fixedly arranged in the motor bearing 2.

[0063] The cylindrical core 42 is movably arranged in the longitudinal direction Z of the switching actuator 30 within the casing 40 and within the permanent magnet 38. The core 42 is larger in the longitudinal direction Z of the switching actuator 30 than the permanent magnet 38 and smaller than the outer dimensions of the casing 40 in the longitudinal direction Z of the switching actuator 30.

[0064] Radially between the radially outer side of the core 42 and the radially inner side of the permanent magnet 38, a friction or sliding element 50 in the form of a friction or sliding sleeve 50 is fixedly arranged with the permanent magnet 38. The frictional or sliding contact properties of the friction or sliding sleeve 50 with respect to the radially outer side of the core 42 are determined by its surface finish or material and may differ between the embodiments depending on the intended purpose.

[0065] Between the remaining radially outer side of the core 42 and the radially inner side of the shell 40, which projects beyond the permanent magnet 38 on both sides in the longitudinal direction Z of the switching actuator 30, an outer air gap 48 is formed, through which a magnetic field can close between the core 42 and the shell 40.

[0066] Based on this general structure of a switchable, hydraulically damping bearing according to the invention, four exemplary embodiments are described below with reference to the Fig. 3 to Fig. 6 explained. Here, a first or upper mechanical limit 52, which limits the upward movement of the core 42 in the longitudinal direction Z of the switching actuator 30, and a second or lower mechanical limit 54, which limits the downward movement of the core 42 in the longitudinal direction Z of the switching actuator 30, are used.

[0067] Fig. Figure 3 shows a schematic section of a switching actuator 30 according to a first embodiment of the invention. In this case, an unequal magnetic force of the unenergized coil 44 in the longitudinal direction Z of the switching actuator 30 is caused by the fact that the inner air gap 46 is unevenly designed relative to the horizontal plane XY. In this embodiment, this is implemented such that the inner air gap 46 is longer downwards than upwards relative to the horizontal plane XY. As a result, stronger magnetic forces of the permanent magnet 38 act above the inner air gap 46 than below the inner air gap 46, so that in the unenergized state of the coil 44, a significant resulting magnetic force pulls the core 42 upwards at height Z until the core 42 abuts the upper mechanical limit 52. In this position, the bypass channel 18 is closed by the diaphragm 20.

[0068] If the coil 44 is now energized in such a way that the static magnetic field of the permanent magnet 38 can be compensated, the core 42 is moved downwards in height Z until it abuts the lower mechanical limit 54. The diaphragm 20 can then move freely in the longitudinal direction Z of the switching actuator 30 between the diaphragm stop 22 and the diaphragm stop 24, thus opening the bypass channel 18.

[0069] Fig. Figure 4 shows a schematic section of a switching actuator 30 according to a second embodiment of the invention. In this case, an unequal magnetic force of the unenergized coil 44 in the longitudinal direction Z of the switching actuator 30 is alternatively generated by the core 42 having a lower recess 42a, which leads to a deflection of the magnetic field of the permanent magnet 38. The lower recess 42a is inclined, so that the outer air gap 48 widens in this area. This type of magnetic field deflection allows for a significant increase in force as well as a significant increase in the possible stroke range. Furthermore, the operating range can be shifted into the negative stroke range, which reduces the overall height of the switching actuator 30.

[0070] Fig. Figure 5 shows a schematic section of a switching actuator 30 according to a third embodiment of the invention. In this case, an alternative unequal magnetic force of the unenergized coil 44 in the longitudinal direction Z of the switching actuator 30 is generated by the casing 40 having a lower recess 40a, which leads to a deflection of the magnetic field of the permanent magnet 38. Here, too, the lower recess 40a is inclined, so that the outer air gap 48 widens in this area. In this way, the force level of the energized characteristic curve can be increased, thereby enabling an increase in the stroke range in an alternative manner.

[0071] Fig. Figure 6 shows a schematic section of a switching actuator 30 according to a fourth embodiment of the invention. In this embodiment, the lower recess 40a of the casing 40 and the lower recess 42a of the core 42 are combined, so that the individual effects can complement and reinforce each other.

[0072] Fig. Figure 7 shows a schematic section of a switching actuator 30 according to a fifth embodiment of the invention. In this case, an unequal magnetic force of the unenergized coil 44 in the longitudinal direction Z of the switching actuator 30 is alternatively generated by the core 42 having an upper recess 42b, which leads to a deflection of the magnetic field of the permanent magnet 38. The upper recess 42b is inclined, so that the outer air gap 48 widens in this area.

[0073] Fig. Figure 8 shows a schematic section of a switching actuator 30 according to a sixth embodiment of the invention. In this case, an unequal magnetic force of the unenergized coil 44 in the longitudinal direction Z of the switching actuator 30 is alternatively generated by the fact that the casing 40 has an upper recess 40b, which leads to a deflection of the magnetic field of the permanent magnet 38. The upper recess 40b is inclined, so that the outer air gap 48 widens in this area.

[0074] Fig. Figure 9 shows a schematic section of a switching actuator 30 according to a seventh embodiment of the invention. In this embodiment, the upper recess 40b of the casing 40 and the upper recess 42b of the core 42 are combined, so that the individual effects can complement and reinforce each other.

[0075] Fig.Figure 10 shows a schematic section of a switching actuator 30 according to an eighth embodiment. In this embodiment, the lower recess 40a of the casing 40, the lower recess 42a of the core 42, and the internal air gap 46, which is unevenly designed relative to the horizontal plane XY, are combined so that the individual effects can complement and reinforce each other. Reference symbol list (part of the description) R radius, radial direction XY (horizontal) plane perpendicular to the longitudinal direction Z Y width, Y direction Z-direction, longitudinal axis, height, Z-axis 2 switchable (hydraulically damping) bearings, engine mounts 4 cones 6 Chamber of Labour 8 Compensation Chamber 10 Partition wall 12 Top 14 Lower part 16 Ring channel 18 (Bypass) Channel 20 Locking element, membrane 22 first locking element stop, first membrane stop 24 second locking element stop, second membrane stop 26 Opening 30 switching actuator 31 Connecting element of the locking element 20 to the core 40 32 Decoupling membrane 34 first window 36 second window 38 permanent magnet 40 first ferromagnetic element, mantle 40a first, lower step of the first ferromagnetic element 40 40b second, upper step of the first ferromagnetic element 40 42 second ferromagnetic element, core, armature 42a first, lower step of the second ferromagnetic element 42 42b second, upper step of the second ferromagnetic element 42 44 electrically conductive coil 46 inner air gap of the mantle 40 48 outer air gap of the core 42 50 Friction element, friction sleeve, sliding element, sliding sleeve 52 first / upper mechanical boundary of the core 42 54 second / lower mechanical boundary of the core 42

Claims

[1] Switchable bearing (2), in particular a switchable hydraulically damping bearing (2), especially as an engine mount (2) for a motor vehicle, with a closing element (20) which is designed to at least partially close and open a channel (18), and a switching actuator (30) which is controllably connected to the closing element (20), wherein the switching actuator (30) comprises the following components: - at least one permanent magnet (38), - at least one first ferromagnetic element (40), - at least one second ferromagnetic element (42), and - at least one electrically conductive coil (44) through which a current flows in the current-carrying state of the switching actuator (30), wherein the aforementioned components of the switching actuator (30) are arranged to be movable relative to each other in such a way that in a first state of the switching actuator (30) the closing element (20) can be positioned in a first position in the longitudinal direction (Z) of the switching actuator (30) and in a second state of the switching actuator (30) the closing element (20) can be positioned in a second position in the longitudinal direction (Z) of the switching actuator (30), wherein the permanent magnet (38) and / or the first ferromagnetic element (40) and / or the second ferromagnetic element (42) is / are designed such that, in the unenergized state of the coil (44), unequal magnetic forces are exerted in the longitudinal direction (Z) of the switching actuator (30), characterized by , that the first ferromagnetic element (40) and / or the second ferromagnetic element (42) has / have at least one recess (40a, 40b, 42a, 42b) perpendicular to the longitudinal direction (Z) of the switching actuator (30). [2] Switchable bearing (2) according to claim 1, wherein the first ferromagnetic element (40) and / or the second ferromagnetic element (42) has a first retraction (40a, 42a) and a second retraction (40b, 42b) which are spaced apart from each other in the longitudinal direction (Z) of the switching actuator (30), wherein the two recesses (40a, 40b, 42a, 42b) are preferably arranged in the longitudinal direction (Z) of the switching actuator (30) at the edge of the first ferromagnetic element (40) and / or at the second ferromagnetic element (42). [3] Switchable bearing (2) according to claim 1 or 2, wherein the recess (40a, 40b, 42a, 42b) or recesses (40a, 40b, 42a, 42b) are inclined to the longitudinal direction (Z) of the switching actuator (30) and are formed increasing in the longitudinal direction (Z) of the switching actuator (30) towards the edge. [4] Switchable bearing (2) according to any one of the preceding claims, wherein the first ferromagnetic element (40) is substantially arranged around the second ferromagnetic element (42), wherein the first ferromagnetic element (40) is fixed and the second ferromagnetic element (42) is movable relative to the first ferromagnetic element (40) in the longitudinal direction (Z) of the switching actuator (30). [5] Switchable bearing (2) according to one of the preceding claims, wherein the first ferromagnetic element (40) substantially surrounds the coil (44) and / or the permanent magnet (38), preferably in a C-shape. [6] Switchable bearing (2) according to any one of the preceding claims, wherein the coil (44) substantially surrounds the permanent magnet (38), preferably in a ring shape, wherein the coil (44) and the permanent magnet (38) are radially spaced apart from each other, preferably at least sectionally, by the first ferromagnetic element (40). [7] Switchable bearing (2) according to claim 6, wherein an air gap (46) is formed between the coil (44) and the permanent magnet (38), at least in sections. [8] Switchable bearing (2) according to claim 7, wherein the air gap (46) in the longitudinal direction (Z) of the switching actuator (30) is asymmetrical. [9] Switchable bearing (2) according to any one of the preceding claims, wherein the second ferromagnetic element (42) is cylindrical in relation to the longitudinal direction (Z) of the switching actuator (30), and wherein the permanent magnet (38), the coil (44) and the first ferromagnetic element (40) are arranged in a ring shape in relation to the longitudinal direction (Z) of the switching actuator (30). [10] Switchable bearing (2) according to one of the preceding claims, further comprising a first mechanical limit (52) of the movement of the second ferromagnetic element (42) in the longitudinal direction (Z) of the switching actuator (30), wherein when the second ferromagnetic element (42) is in contact with the first mechanical limit (52) the switching actuator (30) is in the first state, the coil (44) is de-energized and the channel (18) is closed by positioning the closing element (20) in the first position. [11] Switchable bearing (2) according to claim 10, further comprising a second mechanical limit (54) of the movement of the second ferromagnetic element (42) in the longitudinal direction (Z) of the switching actuator (30), wherein when the second ferromagnetic element (42) is in contact with the second mechanical limit (54) the switching actuator (30) is in the second state, the coil (44) is energized and the channel (18) is opened by positioning the closing element (20) in the second position. [12] Switchable bearing (2) according to any one of the preceding claims, wherein a friction element (50) or a sliding element (50) is arranged between the first ferromagnetic element (40) and / or the permanent magnet (38) and the second ferromagnetic element (42), wherein one side of the friction element (50) or the sliding element (50) is in contact at least section by friction with the first ferromagnetic element (40) and / or the permanent magnet (38) and the opposite side of the friction element (50) or the sliding element (50) is in contact at least section by friction or sliding with the second ferromagnetic element (42). [13] Motor, in particular for a motor vehicle, with a switchable bearing (2) according to one of the preceding claims. [14] Motor vehicle, with an engine according to claim 13.

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