Device with a magnetorheological transmission device

Abstract

The device (100) comprises a magnetorheological transmission device (1) with two rotating components (2, 3) movable relative to each other. A working gap (4) containing a magnetorheological medium (5) is formed between the rotating components (2, 3). An electrical coil assembly (6) serves to generate a controllable magnetic field in the working gap (4). An auxiliary brake (7) serves to brake the rotation of the rotating components (2, 3) when the magnetic field of the coil assembly (6) is lost. The auxiliary brake (7) comprises a magnetic assembly (17) extending in the circumferential direction of the working gap (4), which includes at least one magnetic unit (27) with at least one permanent magnet (37) extending only over a portion of its circumference.

Description

The invention relates to a device having at least one magnetorheological transmission device with at least two rotational components movable relative to one another. At least one effective gap is formed between the rotational components, in which gap a magnetorheological medium is arranged. A controllable magnetic field can be generated in the effective gap by means of at least one electric coil device in order to influence the rotation capability of the rotary components in normal operation.Such devices can be designed, for example, as an operating device and serve for setting operating states. Then, by means of the magnetorheological transmission device, for example, different moments or forces, stops and rasters can be set for the movements. Thus, during operation, a haptic (perceptible) feedback can be transmitted, which supports the user and allows very specific settings and reduces overall the operating complexity. Such control devices are used more and more frequently in a wide variety of devices and, for example, in motor vehicles or medical technology or also in smart devices, in order, for example, to select menus or to perform precise controls. Moreover, such devices are becoming more and more widely used in the operation of computers and game consoles. The device should therefore be very compact and at the same time reliably constructed and have the smallest possible basic moment.For example, such devices can also be used as a steering specification device for specifying a steering movement according to the steer-by-wire concept. High demands are made on such steering specification devices. For example, precise steering feedback and a play-free or jerk-free steering behavior, especially around the center position, and an overall very smooth harmonic steering behavior are required. If the steering unit is designed to be generally (mechanically) rigid (=high basic torque), a haptically troublefree controllability during normal operation (active resetting... ) is no longer possible. Only very smooth steering units (preferably <0.3 Nm, for example <0.1 Nm, basic torque of all steer-by-wire steering components) make possible haptically demanding and harmonic steering movements. In addition, the steering device must be able to provide high torques or to oppose the manual steering movement (the torque then corresponds to a braking torque). This is for example for the purpose of presenting end stops, for supporting during getting out or as a counter torque during very fast rotations or steering movements.A decisive feature of such devices is safety in the event of a fault and, for example, in the event of a magnetic field of the coil device being omitted. Then, the turning motion is no longer opposed by torque and resistance is no longer felt during operation. In order to mitigate such situations, which are sometimes very dangerous, an additional brake can be used to brake the rotation of the rotary components in the event of a malfunction. However, the additional brake frequently leads to an increase in costs, installation space and weight and to an increase in the basic torque.It is therefore the object of the present invention to provide a device with an improved additional brake which meets the requirements discussed above in a particularly advantageous manner.This object is achieved by a device having the features of claim 1. Further advantages and features of the present invention are evident from the general description and from the description of the exemplary embodiments.The device according to the invention comprises at least one magnetorheological transmission device. The transmission device comprises at least two rotational components movable relative to one another. In particular, the rotational components are arranged at least in sections coaxially with respect to one another. At least one (circumferentially extending) effective gap is formed between the rotational components. At least one magnetorheological medium is arranged in the effective gap. The apparatus comprises at least one electrical coil device for generating a controllable magnetic field in the effective gap. In particular, the generation of the magnetic field serves to influence (and preferably brake or release) the rotation capability of the rotational components during normal operation. The device comprises at least one additional brake for braking the rotation capability of the rotational components in the event of a omission of the magnetic field of the coil device and in particular in the event of a fault. The additional brake comprises at least one magnetic device which extends at least partially in the circumferential direction of the effective gap and / or of the rotational components. In particular, the magnetic device extends at least partially along the circumference of the effective gap and / or of the rotational components. The magnetic device comprises at least one magnetic unit. The magnet unit comprises at least one permanent magnet which extends only over part of a circumference (in particular of the effective gap and / or of the rotational components). In particular, the at least one permanent magnet extends over less than 360° of a circumference of 360°. The part of the circumference corresponds in particular to a surrounding segment with an angle of less than 360°.The device according to the invention offers many advantages. A considerable advantage is offered by the permanent magnet or magnets which run only over part of the circumference. As a result, the additional brake can be manufactured considerably more favorably and with less effort. In addition, the magnet device can be mounted more easily and quickly and can also be accommodated in a particularly space-saving manner. A further advantage is that no special tolerance requirements for the integration of the permanent magnets into the transmission device have to be fulfilled. For example, for the integration of ring magnets, tight manufacturing tolerances are necessary for the development of the braking action provided. In addition, ring magnets are very sensitive to handling.The at least one magnet unit is preferably (only) arranged on one of the rotational components and preferably fastened. In particular, all the magnet units of the magnet device are arranged on one (the same) rotational component.Preferably, the at least one magnet unit is arranged and preferably fastened on the radially outer rotational component. In particular, the magnet unit is arranged at least partially on the radial outer side of the rotational component. This enables particularly quick and inexpensive assembly. The at least one magnet unit can also be arranged on the radially inner rotational component. Then, it is arranged in particular at least partially on its radial inner side.The at least one magnet unit is preferably arranged and in particular fastened at least partially on a radial outer side of the rotary component facing away from the effective gap. The magnet unit may protrude at least partially on the outer side. In particular, the entire magnet unit protrudes on the outer side. The magnet unit can also extend at least partially into the rotational component. The magnet unit may be flush with the outer side of the rotary component.In a particularly preferred and advantageous embodiment, the at least one magnet unit can be mounted from radially outside the radially outer rotational component. It is also preferred and advantageous that the at least one magnet unit can be mounted when the medium is arranged in the effective gap. In other words, the at least one magnet unit can be mounted when the effective gap is already filled with the medium. In particular, the magnet unit can be mounted if the rotary components are assembled coaxially as intended. It is also possible for the at least one magnet unit to be mountable from radially inside the radially inner rotational component.In particular, the at least one magnet unit (at least with respect to its at least one permanent magnet) is arranged at a distance from an axis of rotation of the rotational components. In particular, the at least one magnet unit is arranged coaxially to the rotational components and the effective gap. In particular, the magnet unit is arranged with one of the rotational components on a common side of the effective gap. In particular, the other rotational component (on which the magnet unit is not arranged) is located on the opposite side of the effective gap.It is preferred and advantageous that the at least one magnet unit (at least with respect to its at least one permanent magnet) is conductively and preferably magnetically conductively connected to one of the rotational components. In particular, the magnet unit is thereby incorporated into a magnetic circuit through which the magnetic field of the magnetic device flows. In this case, the magnet unit can be conductively connected directly or indirectly (for example by means of a connecting unit) to the rotary component. In particular, the magnet unit has two magnetic poles (a north pole and a south pole). In particular, both magnetic poles are conductively connected to the rotational component.In an advantageous embodiment, the at least one permanent magnet of the at least one magnet unit is connected directly (contacting) to the rotary component. In particular, the rotational component has at least one flattened portion for this purpose at least in a receiving region for the permanent magnet. Preferably, the flattened portion is arranged on a radial outer side. This makes it possible to save expensive permanent magnets with expensive curvatures. In particular, the at least one permanent magnet is planar at least in a contact region for contact with the rotational component.It is also possible for the at least one permanent magnet to be curved (constantly) at least in a contact region for contact with the rotational component. In particular, the curvature of the contact region corresponds to a curvature of the rotational component and in particular to a curvature of its radial outer side or inner side. It is possible for the permanent magnet to be curved overall (and not just in the contact region). In particular, the permanent magnet then has the geometry of a ring segment. The ring segment can also be referred to in particular as a circle segment. In particular, the ring segment extends only over a part of the circumference.In an advantageous and preferred development, the magnetic device comprises at least one (magnetically) conductive connection unit. In particular, the at least one magnet unit (at least with respect to its at least one permanent magnet) is connected (magnetically) conductively to one of the rotational components by means of the at least one connecting unit and is preferably fixedly connected.In particular, the connecting unit forms part of a magnetic circuit, in which the magnetic device is also incorporated. Specifically, the connection unit is connected to a magnetic pole of the permanent magnet and to the rotating component. It is also possible for the connecting unit to be connected to a magnetic pole of the permanent magnet and to an (opposite) magnetic pole of at least one further permanent magnet of the magnet unit. In particular, the permanent magnets provided for the magnet unit are connected either to one another or to the rotary component via at least one connecting unit.The connecting unit can be curved in a contact region for contact with the rotational component. The connecting unit then has in particular the basic geometry of a ring segment. In particular, the curvature of the contact region of the connection unit corresponds to a curvature of the rotational component. It is also possible for the connecting unit to be planar in a contact region for contact with the rotational component. The rotational component then has in particular at least one flattened portion (in a receiving region for the connecting unit).It is possible and advantageous for at least one of the rotary components and in particular at least the rotary component on which the at least one magnet unit is arranged to have at least one separating gap running in the circumferential direction. In particular, the separating gap divides the rotational component into at least two component sections which are in particular magnetically decoupled from one another. In particular, the separation gap provides a magnetic flux barrier. In particular, a magnetic short circuit between the rotational component and the at least one magnet unit (arranged thereon) is thereby prevented. In particular, the separating gap is arranged such that a magnetic field emanating from the magnetic device cannot run bypassing the effective gap. The separating gap can be formed as an air gap. The separating gap can be at least partially filled with a material which is magnetically non-conductive or at least poorly conductive (plastic, metal (e.g. aluminum), etc.). In particular, the component sections are designed to be magnetically conductive. In particular, the separating gap is sealed with respect to the effective gap and / or with respect to the environment. This prevents, in particular, the magnetorheological medium from entering the separation gap or from exiting the separation gap.It is preferred and advantageous that the at least one connecting unit together with the at least one magnet unit provides a conductive connection between the component sections. It is also possible for the magnet unit to comprise at least one horseshoe magnet or to be designed as such. The legs of the horseshoe magnet are then in particular each connected to a component section. As a result, the connecting unit can be dispensed with if required.It is possible and advantageous for the at least one permanent magnet to be arranged on (only) one component section. In particular, the connecting unit extends from the permanent magnets to the opposite component section. It is also possible and advantageous for the magnet unit to comprise at least two permanent magnets, of which at least one permanent magnet is arranged in each case on the component sections. Then, the permanent magnets are preferably conductively connected by the connecting unit. In particular, the connecting unit extends between the permanent magnets of the at least one magnet unit separated by the separating gap.In such embodiments, the connecting unit preferably comprises at least one bridge element or is designed as such. In particular, the bridge element spans the separating gap and is connected to the permanent magnet and the rotational component or to the permanent magnet or to at least one further permanent magnet. In particular, the permanent magnet is then polarized in the radial direction. The permanent magnets of a magnet unit arranged on opposite component sections are then polarized rotated by 180°, in particular. For example, the north pole is rotated from radially outside to radially inside. In particular, the connecting unit corresponds at least in sections to the radial outer side of the permanent magnet. For example, the connecting unit is curved if the permanent magnet is also curved.In an advantageous embodiment, the connecting unit comprises at least two holding elements. In particular, at least one holding element is arranged on a component section. In particular, the holding elements (which belong to a magnet unit) are conductively connected by the at least one permanent magnet of the magnet unit. The permanent magnet is then polarized in particular in the axial direction. The permanent magnet is arranged in particular centered along the separating gap. The holding elements are in particular each arranged axially next to the separating gap.The magnet device can have a three-part construction for each magnet unit provided. The three-part structure comprises in particular two permanent magnets and a connecting unit designed as a bridge element. The three-part structure can also comprise two connecting units designed as holding elements and a permanent magnet arranged therebetween.The connection unit can have at least one fastening section for (magnetically) conductive fastening to the rotational component. In particular, the fastening section is planar. It is also possible for the fastening section to correspond to a curvature of the rotational component. In particular, the rotational component then has at least one flattened portion in its receiving region for the connecting unit.In one embodiment, it is provided that the at least one permanent magnet of the magnet unit is polarized in the axial direction. The magnetic poles are then situated opposite one another in particular in the axial direction. The axial direction runs in particular transversely to the radial direction and / or parallel to the axis of rotation of the rotational components. A configuration is also possible in which the at least one permanent magnet of the magnet unit is polarized in the radial direction. The magnetic poles are then situated opposite one another in particular in the radial direction (transversely to the axis of rotation of the rotational components).In an advantageous development, the at least one permanent magnet of the magnet unit has a cuboidal basic geometry. In particular, the permanent magnet is not curved and / or does not follow a curvature of the rotational component. This enables particularly favorable production and is particularly advantageous if a plurality of magnet units are provided. Such rectangular permanent magnets can be conductively connected to the rotary component directly or by means of the at least one connecting unit. In particular, the permanent magnet is planar at least in the contact region with the rotational component and / or with the connection unit.It is possible for the at least one permanent magnet of the magnet unit to be curved and preferably to have the basic geometry of a ring segment. This may be advantageous under certain conditions despite the more complicated production. For example, this makes it possible to save installation space if only one or a few large magnet units are provided. The connection can be effected directly or by means of the at least one connecting unit. Such a ring segment can extend, for example, over an angle of at least 30° or at least 45° or at least 65° or also at least 90° or more of the circumference.It is preferred that the at least one magnet unit alone or together with the at least one connecting unit provides a magnetic circuit section. The magnetic circuit section is part of a magnetic circuit of the magnetic device. In particular, the magnetic circuit extends from the magnetic circuit section through the rotational component (on which the magnet unit is arranged) and through the effective gap with the magnetorheological medium located therein and through the opposite rotational component and again through the effective gap with the magnetorheological medium located therein and back to the magnetic circuit section. The at least one permanent magnet of the magnet unit is incorporated into the magnetic circuit in such a way that its magnetic poles are connected to one end of the magnetic circuit in each case and thereby close the magnetic circuit. If a plurality of magnet units are provided, the individual magnet units preferably form at least one magnetic circuit section alone or with the at least one connecting unit. In particular, the magnetic device then comprises a plurality of magnetic circuits. In particular, the magnet units are each part of a magnetic circuit.The magnetic circuit section preferably forms a bypass to a magnetic circuit of the transmission device. The transmission device comprises in particular at least one magnetic circuit through which the magnetic flux of the magnetic field of the coil device flows in order to influence the rotation of the rotational components during normal operation. The magnetic circuit section (in particular at least the bypass) is in particular connected at least in sections parallel to the magnetic circuit of the transmission device. If a plurality of magnetic circuits are provided with a respective magnetic circuit section, each magnetic circuit section in particular respectively forms a bypass for the magnetic circuit of the transmission device.It is possible that the magnetic circuit section is directly incorporated into the magnetic circuit of the transmission device. In particular, the magnetic circuit section is then connected in series (or in series) and in particular not in parallel with the magnetic circuit of the transmission device. In particular, the magnetic circuit of the at least one magnet unit is connected in series with the magnetic circuit of the transmission device.It is possible and preferable that the magnetic circuit of the transmission device does not pass through the magnetic circuit section. In particular, the magnetic circuit of the transmission device runs from the rotational component (on which the magnet unit is not arranged) through the effective gap with the magnetorheological medium located therein and through the opposite rotational component (on which the magnet unit is arranged) and through its separating gap and again through the effective gap with the magnetorheological medium located therein and again back into the rotational component. In particular, the magnetic circuit of the transmission device runs through the component sections and the separating gap lying between them. In particular, a field strength or a power of the coil device and the resistance of the separating gap are then matched to one another, such that the magnetic flux of the coil device flows at least predominantly through the separating gap and not through the magnetic circuit section. For such a coordination, it is preferably taken into account that the at least one permanent magnet of the magnet unit has magnetic saturation and thus represents a correspondingly high resistance for the magnetic circuit of the transmission device. The resistance of the separating gap is determined in particular by the width and / or the filling. In particular, the (magnetic) resistance of the separating gap is dimensioned such that it provides a magnetic flux barrier for the magnetic field of the magnet unit, but not for the magnetic field of the coil device.It is possible for the magnetic circuit of the transmission device to extend from the rotary component (on which the magnet unit is not arranged) through the active gap with the magnetorheological medium located therein and then from there (bypassing the rotary component with the separating gap) directly back again to the rotary component (on which the magnet unit is not arranged). In such a configuration, a field strength or a power of the coil device and a resistance of the separating gap are matched to one another such that the magnetic flux of the coil device flows at least for a major part not through the separating gap but through the effective gap with the magnetorheological medium located therein.In a preferred and advantageous embodiment, the magnet device comprises a plurality of magnet units. Strong emergency braking torques can thus be generated with very compact and cost-effective permanent magnets. Preferably, the magnet units (at least with respect to their respective at least one permanent magnet) are distributed over the circumference in a spaced manner. A lining-up without a distance can also be provided.Preferably, the magnet units are symmetrically distributed over the circumference. As a result, the emergency braking torque can be cancelled reliably and inexpensively with the magnetic field of the coil device during normal operation. The magnet units can also be distributed asymmetrically over the circumference. In this case, an additional electrical coil device is provided in particular.In particular, the magnet units are arranged coaxially with respect to the effective gap. In particular, the magnet units are arranged in a row along the separating gap. The magnet units can span the separating gap. The magnet units can also be arranged next to the separating gap on one of the component sections in each case. In particular, each magnet unit provides a magnetic circuit section. In particular, the individual magnet units are identical or at least analogous and, for example, mirror-symmetrical.The magnetic device comprises in particular at least two magnetic units. The magnet device can also comprise at least three or at least four or at least five or at least six magnet units. The magnet device can comprise at least eight or at least ten or at least twelve magnet units. For example, up to 24 or up to 36 magnetic units or more may be provided. In particular, the number of magnet units is matched to the size of the transmission device and the desired emergency braking torque.Preferably, the magnet units taken together extend over an angle of at least 45° or at least 65° or at least 75° and preferably at least 80° of the circumference. This enables a reliable provision of the emergency braking torque. In this case, the individual magnetic units have in particular a length of only a few degrees of the circumference.In particular, at least one connecting unit is assigned to each of the magnet units. In particular, the connecting units are also distributed over the circumference at a distance. In particular, the magnetic units each form a pre-assembly unit with their at least one associated connecting unit. This further simplifies the assembly.It is possible for a common connecting unit to be assigned to a plurality of magnet units or to all magnet units. In particular, a plurality of or even all of the magnet units are then fastened to the rotary component by means of the common connecting unit. In particular, the common connecting unit has the basic geometry of a ring segment and preferably corresponds to the curvature of the rotational component. In particular, the common connecting unit extends over at least part of the circumference. The common connecting unit can also extend over the entire circumference (360°) and be designed, for example, as a closed ring. The common connecting unit can form a pre-assembly unit with the magnet units. By mounting the pre-mounting unit, several or all magnetic units can then be handled and fastened at the same time.In particular, the magnet units alone or with their at least one associated connecting unit each provide a magnetic circuit section. In particular, each magnet unit is assigned at least one connecting unit in order to form a magnetic circuit section. If a plurality of magnet units have at least one common connecting unit, each magnet unit forms in particular together with the common connecting unit in each case a magnetic circuit section.In an advantageous embodiment, only one magnet unit is provided. In particular, the magnet unit then extends over an angle of at least 45° or at least 75° and preferably at least 80° of the circumference. In particular, the magnet unit extends over an angle of at least 88° and preferably at least 90° (at least one quarter) of the circumference. In particular, the magnet unit extends over an angle of a maximum of 180° of the circumference. This offers advantages with regard to the installation space and at the same time also enables a correspondingly inexpensive assembly, for example from the radially outside. Two such magnetic units can also be provided.In all embodiments, it is preferred and advantageous that at least one electric opposing field generating device is assigned to the magnetic device. In particular, the opposing field generating device is suitable and designed to at least partially attenuate or eliminate the at least one magnetic field emanating from the magnetic device. In particular, for this purpose, the opposing field generating device generates at least one magnetic field which is in the opposite direction to the at least one magnetic field of the magnetic device.The opposing field generating device is preferably provided by the coil device of the transmission device. It is also preferred and advantageous that the opposing field generating device comprises at least one additional electrical coil device. In particular, the additional coil device then provides at least one magnetic field which is opposite to the at least one magnetic field of the magnetic device.It is possible and advantageous for the auxiliary coil device to have at least one auxiliary coil for each provided magnet unit. In particular, the additional coil is arranged on the magnet unit and / or on the at least one associated connection unit. In particular, at least one additional coil is provided for each magnet unit. In particular, at least one additional coil is provided for each magnetic circuit of the magnetic device. As a result, the magnetic fields of magnet units distributed asymmetrically over the circumference can also be reliably eliminated.In an advantageous embodiment, it is provided that the at least one magnetic field emanating from the magnetic device can be used to amplify the magnetic field emanating from the coil device of the transmission device. In particular, the magnetic fields of the individual magnetic units reinforce the magnetic field emanating from the transmission device. Such amplification is provided in particular during normal operation. In particular, the coil device is suitable and configured to generate a magnetic field which runs in the same direction as the at least one magnetic field of the magnetic device. Thus, with the same current consumption of the coil device, a stronger braking torque can be generated.The device can be designed as a steering specification device for specifying a steering command according to the steer-by-wire concept. In particular, one of the rotational components is then coupled to a steering unit and, for example, a steering wheel. In particular, the movability of the steering unit can thereby be braked in a targeted manner. The steering specification device can comprise at least one drive device for generating a torque acting on the steering unit, so that the steering unit can be actively moved. In particular, the transmission device is then designed as a clutch device, so that the drive device can be coupled to the steering unit with adjustable clutch torque. In this case, in particular one of the rotary components can be coupled to the drive device and one of the rotary components can be coupled to an output.The steering specification device can comprise an actuator device which serves for converting a steering movement carried out with the steering unit into a vehicle movement. In particular, the steering unit and the actuator device are operatively connected only according to the steer-by-wire concept.The device can be designed as an operating device for setting operating states by means of rotational movements and / or linear movements (which are converted into rotational movements). In particular, the movement resistance of the rotational movement can be adjusted in a targeted manner. Such an operating device is designed, for example, as a rotary knob or a joystick or the like.In particular, a force transmission or torque transmission can be changed in a targeted manner by means of the transmission device. In particular, by means of the coil device and its magnetic field in the effective gap, the force transmission or the torque transmission between the rotational components can be adjusted. In particular, this also results in a change in the movement resistance for the rotation of the rotational components. The transmission device can be used as a clutch device or as a brake device. The rotary components then serve in particular as clutch components or as brake components and can be referred to as such. The torque can also be referred to as braking torque or clutch torque.When the at least one magnet unit or the magnet unit is mentioned in the context of the present invention, all provided magnet units of the magnet device are meant in particular. In particular, the at least one magnet unit extends only over a part of the circumference. The at least one magnet unit consists in particular of at least one permanent magnet. The magnet unit may consist of only one permanent magnet. The magnet unit can consist of at least (only) two permanent magnets. It is also possible for the magnet unit to consist of at least three or at least four or more permanent magnets. When the at least one permanent magnet is mentioned in the context of the present invention, all permanent magnets of the magnet unit are meant in particular. The permanent magnets of a magnet unit can be arranged spaced apart or touching. It is possible for the magnet unit to comprise further components in addition to the permanent magnets.In particular, the at least one magnet unit provides at least one magnetic field which acts on the magnetorheological medium located in the active gap, so that it can brake the rotation of the rotational components by means of the additional brake in the event of the magnetic field of the coil device being omitted. In particular, the magnetic device of the additional brake acts on the magnetorheological medium arranged in the effective gap. In particular, the magnetic field of the coil device and the magnetic field of the magnet device act on the same effective gap and preferably also on the same magnetorheological medium. In particular, the additional brake and the transmission device use the same effective gap and the same magnetorheological medium and preferably also at least partially the same conductive sections of the rotational components.In particular, a common effective gap is provided for the transmission device and the additional brake. In particular, the effective gap formed between the rotational components also provides the effective gap for the additional brake. In particular, the effective gap is formed circumferentially around one of the rotational components. The effective gap can have at least one or also at least two or more gap sections. In this case, the magnetic field of the magnetic device can act on the same gap section and / or on another (adjacent) gap section of the effective gap. In particular, the gap sections are connected to one another and in particular flow-connected. Such a structural integration of the additional brake into the transmission device requires particularly little installation space.The braking torque of the additional brake is referred to as the emergency braking torque in the context of the present invention. This is also understood to mean, in particular, other possible uses of the braking torque, for example for braking in standby or with the transmission device switched off or for amplifying a transmission torque of the transmission device. The transmission torque of the transmission device can be a braking torque or a clutch torque.In particular, the permanent magnet provides the magnetic field independently of a power supply of the additional brake and the coil device. It is possible that the permanent magnet is provided by a material with suitable remanent properties, so that it can be demagnetised and magnetized by a magnetic field (for example by means of the coil device). When a direction of the magnetic field is mentioned in the context of the present invention, the direction of the magnetic flux (in particular in a magnetic circuit) is meant in particular.In particular, the coil device is fastened to one of the rotational components. In particular, the coil device and the at least one magnet unit are fastened to different (opposite) rotational components. In particular, the coil device is not fastened to the rotational component which has the separating gap. In particular, rotary components are at least partially magnetically conductive. In particular, the rotary components are at least partially made of a magnetically conductive material. In particular, rotary components are designed to be magnetically conductive at least where the magnetic circuit is provided.In all configurations, it is particularly preferred and advantageous for the magnetorheological medium to be designed as a powder. In particular, the powder is taken up in a gas and preferably in air. In particular, the magnetorheological medium comprises magnetically responsive (magnetizable) particles and gas as filling medium. In particular, the magnetically responsive particles are accommodated in air. In particular, the magnetorheological medium is designed as a powder. With such a magnetorheological medium, the invention presented here enables a particularly low basic torque. Alternatively, it is conceivable and possible for the magnetorheological medium to comprise magnetizable particles and a carrier liquid, such as oil, water or alcohol.It is particularly preferred that the magnetizable particles (in each case) consist predominantly of carbonyl iron powder or derivatives thereof. Other magnetically responsive particles are also possible. The magnetizable particles may have coatings for protection against abrasion and / or corrosion and / or additional constituents in order to make the magnetically responsive particles more stable, abrasion-resistant and / or lubricious during operation. The magnetorheological medium may comprise, for example, a graphite admixture.Further advantages and features of the present invention result from the exemplary embodiments which are explained below with reference to the attached figures.Shown therein are: FIG. 1 shows a purely schematic illustration of a device according to the invention in a sectional side view; FIG. 2 shows the device of FIG. 1 in a sectional front view; FIG. 3 shows a further device in a sectional side view; FIG. 4 shows the device of FIG. 3 in a sectional front view; FIG. 5 shows a further device in a sectional side view; FIG. 6 shows the device of FIG. 5 in a sectional front view; FIGS. 7 and 8 show detailed representations of a device in various operating states in sectioned side views; FIGS. 9 and 10 show a further device in various operating states in sectional side views; and FIG. 11 shows a detailed illustration of the device of FIG. 3 in a perspective view.FIGS. 1 and 2 show an apparatus 100 according to the invention having a magnetorheological transmission device 1 with two rotational components 2, 3. the apparatus 100 is designed here as a steering specification device 300 for controlling a vehicle according to the steer-by-wire concept. For this purpose, one of the rotary components 2, 3 is connected to a steering unit 301 and, for example, a steering wheel. The transmission device 1 can thereby generate haptic feedback at the steering unit 301 or engage in the torque of a drive device not shown here. However, the device 100 can also be designed as another type of operating device and, for example, as a rotary knob or thumb roller.Between the rotary components 2, 3 an effective gap 4 is formed, in which a magnetorheological medium 5 is arranged. The dimensioning of the effective gap 4 is not drawn to scale here and in the other figures for reasons of visibility. A seal 14 is provided for sealing the effective gap 4. The inner rotary component 2 is rotatably mounted on the outer rotary component 3 by means of a bearing unit 12 and, for example, one or more slide bearings.A magnetic field is generated via a coil device 6 fastened to the inner rotary component 2. The magnetic field influences the medium 5, so that the movability of the rotary components 2, 3 is acted upon by a targeted torque.The magnetically conductive sections of the rotary components 2, 3 that project into the effective gap 4 can be equipped with a circumferential contour. This results in a different gap height in the circumferential direction, wherein the elevations act as magnetic field concentrators. Here, for example, the inner rotary components 2 are equipped with a star contour 24.An additional brake 7 with a magnetic device 17 serves to brake the rotation of the rotary components 2, 3 in the event of a magnetic field of the coil device 6 being omitted and, for example, in the event of a malfunction. The magnetic device 17 comprises a magnetic unit 27 with two permanent magnets 37 here. the magnetic field of the magnetic unit 27 extends here in a magnetic circuit 47 drawn in dashed lines.Since the magnetic circuit 47 also extends through the effective gap 4 and the medium 5, the rotation of the rotary components 2, 3 is braked as a result. The arrows indicate the direction of flow of the magnetic field in the magnetic circuit 47. The dashed line within the permanent magnets 37 symbolically indicates the polarization of the permanent magnets 37.In order to prevent a magnetic short circuit between the magnet unit 27 and the rotating components 3, a separation gap 43 is formed in the rotating component 3. The separating gap 43 results in two component sections 53 that are magnetically decoupled from one another. A permanent magnet 37 of the magnet unit 27 is connected to each component section 53 in a magnetically conductive manner. The permanent magnets 37 are connected to one another by means of a connecting unit 8, so that the magnetic circuit 47 is closed. The connecting unit 8 is designed here as a bridge element 28.The magnet unit 27 here forms with its connection unit 8 a magnetic circuit section 87 which provides a part of the magnetic circuit 47. With respect to the magnetic circuit of the coil device 6 in the normal operation, the magnetic circuit section 87 constitutes a bypass.The magnet unit 27 extends here only over a part of the circumference which corresponds to an angle 37 bof slightly less than 90°. As a result, permanent magnets 37 can be used which are considerably more cost-effective and easier to produce than, for example, ring magnets.In addition, the magnet unit 27 is fastened here to a radial outer side 13 of the outer rotary component 3. In this case, the magnet unit 27 can be mounted after the rotary components 2, 3 have been assembled and the effective gap 4 has been filled with the medium 5. This enables particularly economic and inexpensive assembly.The permanent magnets 37 are fastened here directly contacting a receiving region 23 of the outer side 13 of the rotary component 3. For this purpose, they have a contact region 37 awhich follows the curvature of the receiving region 23 or of the entire outer side 13 of the rotary component 3.The magnet unit 27 here has the basic geometry of a ring segment. Accordingly, the permanent magnets 37 are configured as ring segments. The bridge element 28 also follows the curvature of the permanent magnets 37 and is formed as a ring segment. This results in a very compact construction overall, so that the diameter of the transmission device 1 is only insignificantly increased due to the additional brake 7.The additional brake 7 shown here offers a reliable emergency braking torque with its magnet unit 27 and the specific course of the magnetic circuit 47. As a result, the rotary components 2, 3 cannot be rotated without resistance in the event of a fault. Resistanceless turning could result in the steering commander 300 being coated and thus very dangerous steering movements.In order to cancel the emergency braking torque during normal operation, the magnetic field of the magnetic unit 27 is superimposed in a targeted manner with a magnetic field of a counter-field generating device 57. For this purpose, the opposing field generating device 57 generates a magnetic field which is directed opposite the magnetic field of the magnet unit 27.In the device 100 shown here, the opposing field generating device 57 can be provided by the coil device 6 of the transmission device 1. However, the single magnet unit 27 is arranged here only on a part of the circumference. When its magnetic field is eliminated by the coil device 6, a braking torque is present. This is because, when the magnetic field of the coil device 6 cancels the magnetic field of the magnet unit 27 in the associated angular range, an effective magnetic field of the coil device 6 remains in the remaining angular range of the circumference.If a complete elimination of the emergency braking torque is desired, the device 100 shown here can be equipped with an additional coil device 67, which is shown in more detail in FIGS. 7 and 8. The auxiliary coil device 67 comprises an auxiliary coil device 67, which is arranged here on the connecting unit 8. If a plurality of asymmetrically distributed magnet units 27 are provided, the supplementary coil device 67 comprises at least one supplementary coil 77, for example, for each magnet unit 27.The auxiliary coil 77 is incorporated in the magnetic circuit 47 of the magnet unit 27. If the auxiliary coil 77 is not energized (as shown in FIG. 7 ), the course of the magnetic field in the magnetic circuit 47 is not influenced. When the coil is energized (shown in FIG. 8 ), it generates a magnetic field that is oriented opposite to the magnetic field of the magnet unit 27. This results in the magnetic circuit 47 a, drawn in dashed lines in FIG. 8, for the magnet unit 27 and the magnetic circuit 77 afor the additional coil 77.In FIGS. 7 and 8, the magnet unit 27 is equipped purely by way of example with only one permanent magnet 37. Accordingly, the bridge member 28 is formed to connect the permanent magnet 37 to the opposing component portion 53. Such an embodiment can also be provided for the devices 100 of FIGS. 1 to 4. However, the device 100 presented in FIGS. 7 and 8 can also be equipped with a magnet unit 27 or a bridge element 28, as is shown in FIGS. 1 and 2 or 3 and FIG. 4.FIGS. 3 and 4 show a variant of the device 100 presented above, in which a plurality of magnet units 27 distributed symmetrically over the circumference are provided. Thereby, the magnetic field of the magnetic device 17 can be completely eliminated by the magnetic field of the coil device 6, if necessary. If an asymmetric distribution of the magnet units 27 is provided, the magnet units 27 are preferably each equipped with an additional coil 77. The function of the additional coil 77 for eliminating the magnetic field of the magnetic device 17 then takes place in particular as described with reference to FIGS. 7 and 8.The magnet units 27 here each have two rectangular parallelepiped permanent magnets 37 with planar contact regions 37 a. This results in low production complexity and permanent magnets 37 with low production precisions can be used in the connection to the rotary component 3. The magnet units 27 are connected by means of cuboidal bridge elements 28. In order to ensure a well-conductive connection, receiving regions 23 for the permanent magnets 37 are formed on the outer side 13 of the rotary component 3, which receiving regions have flattened portions 33. This embodiment can be seen particularly well in the detailed illustration of FIG. 11.FIGS. 5 and 6 show a variant of the device 100, in which the magnet units 27 are distributed over the circumference and each have a rectangular permanent magnet 37. The permanent magnets 37 have an axial polarization here.In order to be able to connect the individual magnet units 27 to both component sections 53, two connecting units 8 are provided here for each magnet unit 27. The connecting units 8 are designed here as holding elements 38 which are conductively connected to a magnetic pole and a component section 53 in each case. However, it is also possible for two holding elements 38 to be designed for connecting all the magnet units 27. The holding elements 38 are then designed, for example, as encircling rings.The holding elements 38 each have a fastening section 18 here, which is adapted to the curvature of the outer side 13 of the rotary component 3 in the receiving region 23 for the permanent magnets 37. This variant also enables the economic and advantageous use of rectangular permanent magnets 37.FIG. 9 shows the device 100 of FIGS. 5 and 6 in a normal operation. The coil device 6 of the transmission device 1 is active and generates a magnetic field which extends through a magnetic circuit 16 and is directed opposite the magnetic field of the magnetic device 17. The magnetic field of the coil device 6 displaces the magnetic field of the magnetic device 17 from the effective gap 4 and the emergency braking torque can thereby be completely cancelled out. The magnetic field of the magnetic device 17 during this flows through a magnetic circuit 47, which here extends at least partially through the component sections 53 and the separating gap 43.Depending on the magnetic resistance of the separating gap 43, the magnetic circuit 47 can, however, also extend at least partially through the air. A magnetic circuit 47 would then result, which runs through the magnetic circuit section 87 and the air layers lying radially further outward from the magnetic circuit section 87. In principle, it is important for cancelling the emergency braking torque that the magnetic circuit 47 no longer runs through the effective gap 4. In addition, the magnetic circuit 16 of the coil device 6 should not pass through the opposite rotating component 3.If the rotation of the rotary components 2, 3 is to be decelerated in normal operation, a stronger magnetic field is generated with the coil device 6. This then extends through a magnetic circuit, not shown here, which also runs through the component sections 53 and overcomes the separating gap 43.FIG. 10 shows the device 100 of FIGS. 5 and 6 in a normal operation in which a particularly high braking torque and / or a particularly energy-saving operation are desired. For this purpose, the coil device 6 generates a magnetic field which runs in the same direction as the magnetic field of the magnetic device 17. This results in the magnetic circuit 16 shown here for the magnetic field of the coil device 6 and the magnetic circuit 47 for the magnetic device 17.List of reference numbers:1 Transmission device 2 Rotational component 3 Rotational component 4 Effective gap 5 Medium 6 Coil device 7 Additional brake 8 Connecting unit 12 Bearing unit 13 Outer side 14 Seal 16 Magnetic circuit 17 Magnetic device 18 Fastening section 23 Receiving region 24 Star contour 27 Magnetic unit 28 Bridge element 33 Flattened portion 37 Permanent magnet 37 aContact region 37 b Angle 38 Holding element 43 Separating gap 47 Magnetic circuit 47 aMagnetic field 53 Component section 57 Opposing field generation device 67 Additional coil device 77 Additional coil 77 aMagnetic field 87 Magnetic circuit section 100 Device 300 Steering specification device 301 Steering unit

Claims

Device (100) comprising a magnetorheological transmission device (1) with at least two rotational components (2, 3) movable relative to one another, comprising a radially inner rotational component (2) and a radially outer rotational component (3), wherein an effective gap (4) is formed between the rotational components (2, 3) and wherein a magnetorheological medium (5) is arranged in the effective gap (4), and comprising at least one electrical coil device (6) for generating a controllable magnetic field in the effective gap (4) in order to influence the rotation capability of the rotational components (2, 3) in normal operation, and comprising an additional brake (7) for braking the rotation capability of the rotational components (2, 3) in the event of a magnetic field of the coil device (6) being omitted and in particular in the event of a fault, characterized in that the additional brake (7) has a magnet device (17) extending at least partially in the circumferential direction of the effective gap (4), which comprises at least one magnet unit (27) having at least one permanent magnet (37) extending only over part of a circumference.The device (100) according to the preceding claim, wherein the at least one magnet unit (27) is arranged and preferably fixed to one of the rotating components (2, 3).The device (100) according to any one of the preceding claims, wherein the at least one magnet unit (27) is arranged on the radially outer rotational component (3).Device (100) according to one of the preceding claims, wherein the at least one magnet unit (27) is arranged at least partially on a radial outer side (13) of the rotary component (2, 3) facing away from the effective gap (4).Device (100) according to one of the preceding claims, wherein the at least one magnet unit (27) can be mounted from radially outside the radially outer rotational component (3) and / or wherein the at least one magnet unit (27) can be mounted when the medium (5) is arranged in the effective gap (4).The device (100) according to any one of the preceding claims, wherein the at least one magnet unit (27) is arranged spaced apart from a rotational axis of the rotary components (2, 3) and coaxial to the rotary components (2, 3) and the effective gap (4).The device (100) according to any one of the preceding claims, wherein the at least one magnet unit (27) is magnetically conductively connected to one of the rotational components (2, 3).Device (100) according to the preceding claim, wherein the at least one permanent magnet (37) is directly connected to the rotary component (2, 3) and wherein the rotary component (2, 3) has at least one flattened portion (33) for this purpose at least in a receiving region (23) for the permanent magnet (37) or wherein the at least one permanent magnet (37) is formed curved for this purpose at least in a contact region (37a) for contact with the rotary component (2, 3).The device (100) according to any one of the preceding claims, wherein the magnetic device (17) comprises at least one magnetically conductive connection unit (8), and wherein the at least one magnetic unit (27) is magnetically conductively connected to one of the rotational components (2, 3) by means of the at least one connection unit (8).The device (100) according to any one of the preceding claims, wherein one of the rotary components (2, 3) has a separating gap (43) running in the circumferential direction, which divides the rotary component (2, 3) into at least two component sections (53), so that a magnetic short circuit between the rotary component (2, 3) and the at least one magnet unit (27) is prevented.The device (100) according to the two preceding claims, wherein the at least one connection unit (8) together with the at least one magnet unit (27) provides a conductive connection between the component portions (53).The device (100) according to the preceding claim, wherein the at least one permanent magnet (37) is arranged on a component section (53), and wherein the connecting unit (8) extends from the permanent magnet (37) to the opposite component section (53), or wherein the magnet unit (27) comprises at least two permanent magnets (37), and wherein at least one permanent magnet (37) is arranged in each case on the component sections (53), and wherein the permanent magnets (37) are conductively connected by the connecting unit (8).The device (100) according to claim 11, wherein the connecting unit (8) comprises at least two holding elements (38) and wherein at least one holding element (38) is arranged on a component section (53) in each case and wherein the holding elements (38) are conductively connected by the at least one permanent magnet (37).The device (100) according to claim 9, wherein the at least one connection unit (8) comprises at least one fastening section (18) for conductive fastening to the rotating component (2, 3) and wherein the fastening section (18) is planar or wherein the fastening section (18) corresponds to a curvature of the rotating component (2, 3).The device (100) according to any one of the preceding claims, wherein the at least one permanent magnet (37) is polarized in the axial direction or wherein the at least one permanent magnet (37) is polarized in the radial direction.Device (100) according to one of the preceding claims, wherein the at least one permanent magnet (37) has a cuboidal basic geometry or wherein the at least one permanent magnet (37) is of curved design and preferably has the basic geometry of a ring segment.The device (100) according to any one of the preceding claims, wherein the at least one magnet unit (27) alone or together with the at least one connection unit (8) provides a magnetic circuit section (87), which is part of a magnetic circuit (47) of the magnetic device (17), and wherein the magnetic circuit (47) extends from the magnetic circuit section (87) through the rotating component (2, 3) and the effective gap (4) with the medium (5) located therein and the opposite rotating component (2, 3) and again through the effective gap (4) with the medium (5) located therein and back to the magnetic circuit section (87).The device (100) according to the preceding claim, wherein the magnetic circuit section (87) forms a bypass to a magnetic circuit (16) of the transmission device (1) or wherein the magnetic circuit section (87) is directly incorporated into a magnetic circuit (16) of the transmission device (1).The apparatus (100) according to any one of the preceding claims, wherein the magnet device (17) comprises a plurality of magnet units (27) and wherein the magnet units (17) are distributed over the circumference in a spaced manner.The device (100) according to the preceding claim, wherein the magnet units (27) are symmetrically distributed over the circumference.The device (100) according to any one of the two preceding claims, wherein the magnet units (27) taken together extend over an angle of at least 75° and preferably at least 80° of the circumference.The device (100) according to any one of the preceding claims, wherein only one magnet unit (27) is provided and wherein the magnet unit (27) extends over an angle of at least 75° and preferably at least 80° of the circumference.Apparatus (100) according to one of the preceding claims, wherein at least one electric opposing field generating device (57) is assigned to the magnetic device (17), and wherein the opposing field generating device (57) is suitable and designed to attenuate or eliminate the at least one magnetic field emanating from the magnetic device (17).The apparatus (100) according to the preceding claim, wherein the opposing field generating device (57) is provided by the coil device (6) of the transmission device (1) and / or wherein the opposing field generating device (57) comprises at least one additional electrical coil device (67) and wherein the additional coil device (67) preferably comprises at least one additional coil (77) for each provided magnet unit (27).The apparatus (100) according to the preceding claim, wherein the at least one magnetic field emanating from the magnetic device (17) can be used to amplify the magnetic field emanating from the coil device (6) of the transmission device (1).Device (100) according to one of the preceding claims, designed as a steering presetting device (300) for presetting a steering command according to the steer-by-wire concept, wherein one of the rotary components (2, 3) is coupled to a steering unit (301), so that the movability of the steering unit (301) can be braked in a targeted manner.

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