MAGNETORHEOLOGICAL BRAKE DEVICE

Description

[0001] The invention relates to a magnetorheological braking device with a stationary holder and at least two braking components and / or damper components. The magnetorheological braking device according to the invention can be used in a variety of technical fields for braking relative to one another. The magnetorheological braking device according to the invention can also be used as a haptic operating device, for example, in the operation of technical devices in vehicles, e.g., as a rotary control; rotary / push control; for infotainment, the air conditioning system (temperature, ventilation level, distribution, etc.).), as a gear selector, for navigation, cruise control, distance control, seat adjustment, in the steering or steering wheel, for chassis adjustment, driving mode adjustment, windshield wiper adjustment, window or sunroof adjustment, parking assistant or for setting (partially) autonomous driving or as a steering wheel replacement. It can be used in motor vehicles, aircraft and airplanes, ships, boats, agricultural machinery (tractors, combine harvesters, harvesters, other field machinery for agriculture), construction machinery and material handling machinery (forklifts, etc.) or in medical or industrial systems.The invention can also be used in the operation of or as an input device for washing machines, kitchen / household appliances and equipment, radios, cameras and film cameras, hi-fi and television systems, smart devices, smart home devices, laptops, PCs, smartwatches, in a crown wheel of wristwatches or as a computer mouse or as a rotary wheel in a computer mouse or controllers, game consoles, gaming equipment, rotary knob in a keyboard or other devices.

[0002] Magnetorheological fluids, for example, contain extremely fine ferromagnetic particles, such as carbonyl iron powder, distributed in an oil. Magnetorheological fluids use approximately round or spherical particles with a manufacturing-related diameter of 1 to 10 μm, although the particle size and shape are not uniform. When such a magnetorheological fluid is exposed to a magnetic field, the carbonyl iron particles of the magnetorheological fluid interlink along the magnetic field lines, so that the rheological properties of the magnetorheological fluid (MRF) are significantly influenced depending on the shape and strength of the magnetic field (transferable shear stresses).

[0003] DE 10 2018 100 390 A1 of the applicant discloses a control knob with a magnetorheological braking device, wherein rolling elements are arranged in the braking gap. DE 10 2012 017 423 A1 discloses a transmission device with two coupling components that move translationally relative to each other and between which a shear gap is formed.

[0004] DE 10 2020 106 328 B3 and DE 10 2020 127 055 A1, published after the priority date, show rotary dampers with a star contour in the gap filled with an MRF, so that a circumferential gap with a variable gap height is created in the area of ​​the star contour.

[0005] WO 2012 / 034697 A1 discloses a magnetorheological transmission device comprising two coupling components whose coupling intensity can be influenced. To influence the coupling intensity, a channel containing a magnetorheological medium is provided. The magnetorheological medium in the channel is influenced via a magnetic field. Rotating bodies are provided in the channel, on which acute-angled regions containing the magnetorheological medium are provided. The channel, or at least a portion thereof, can be subjected to the magnetic field of a magnetic field generating device in order to selectively (magnetically) link the particles and wedge them with the rotating body or release them. This magnetorheological transmission device can also be used on a rotary knob for operating technical devices.Such a magnetorheological transmission device works and allows the transmission of quite high forces or torques while maintaining a relatively small design or volume.

[0006] WO 2012 / 034697 A1 also discloses a rotary knob or control knob in which the actual knob is mounted so that it can rotate around a shaft. The braking torque can be controlled via the magnetic field generated by an electric coil. If a higher braking torque is desired, cylindrical rollers can be used instead of spherical rotating bodies, so that the magnetic field acts over a longer distance or a larger area (magnetic field concentration and wedge formation occur over a larger area). It has been shown, particularly for rotary knobs or control knobs with a relatively small diameter, that lengthening the rolling elements does not necessarily lead to an increase in the maximum braking torque that can be generated. It has been found that this is because the magnetic field is closed by, or must pass through, the central shaft.The small diameter of the shaft limits the braking torque that can be generated, as the magnetic field required for braking quickly saturates in the (shaft) material. The material through which the magnetic field flows no longer allows any higher magnetic flux, which is why a stronger magnetic field cannot reach the rollers. The smallest cross-section through which the magnetic field flows in the overall magnetic circuit defines the maximum possible magnetic flux and thus the maximum braking torque in the braking device. The use of longer rollers as rotating bodies can then even have a detrimental effect on the braking torque that can be generated, as the magnetic field is distributed over the longer roller surface. The field strength is lower (low magnetic field concentration). Because the achievable braking effect is not linearly dependent on the magnetic field, but increases disproportionately with stronger magnetic fields, the achievable braking effect decreases disproportionately with weaker magnetic fields.

[0007] It is therefore the object of the present invention to provide a magnetorheological braking device which, in particular even with small or even very small diameters, allows a high braking torque (torque) or a higher braking torque (torque) than is the case in the prior art.

[0008] This object is achieved by a magnetorheological braking device having the features of claim 1. Preferred developments of the invention are the subject of the dependent claims. Further advantages and features of the magnetorheological braking device will become apparent from the general description and the description of the exemplary embodiments.

[0009] A magnetorheological braking device according to the invention comprises a stationary holder and a brake housing and at least two brake components. One of the two brake components is connected to the holder in a rotationally fixed manner, and the two brake components are continuously rotatable relative to one another. A first brake component extends in an axial direction and comprises a core made of a magnetically conductive material that extends in the axial direction. The second brake component comprises a hollow casing part that can be rotated around the first brake component. A circumferential gap is formed between the first and second brake components and is at least partially and in particular completely filled with a magnetorheological medium. The magnetorheological medium wets the brake components. (At least) one electrical coil is accommodated in the brake housing.At least one star contour with magnetic field concentrators formed thereon is arranged or accommodated between the shell part and the core. These magnetic field concentrators extend (in particular radially and / or axially) into the gap, creating a circumferential gap region in the area of ​​the star contour with a variable gap height (across the circumferential angle). The star contour comprises at least one stack of (narrow) star laminations. The width of a star lamination is particularly narrow compared to the width / total width of the stack.

[0010] The first braking component defines an axial direction. However, the first braking component can also be designed to be at least locally angled to the axial direction. The formulation that the core of the first braking component extends in the axial direction is understood, within the meaning of the present invention, to mean that the core also extends at least substantially in the axial direction. The core can have a profile that has a slight angle to the axial direction. For example, the core can also be oriented at an angle of 2.5°, 5°, 10°, or 15° to the axial direction. The winding of the electrical coil can be radial around the core or can also be oriented (likewise not exactly) in the axial direction around the core. The electrical coil can also be at an angle of 5°, 10°, 15°, or the like to the axial or radial direction.In the case of an axial winding of the electrical coil around the core, it is preferred that an angle between the orientation of the core and the axial direction and an angle of the winding of the electrical coil to the axial direction is less than 20° and in particular less than 10°.

[0011] The magnetorheological braking device according to the invention has many advantages. A significant advantage of the magnetorheological braking device according to the invention is that a high braking torque (high shear stresses) can be generated due to the star or star-like contour with the magnetic field concentrators.

[0012] A particular advantage arises from the fact that the magnetic field concentrators are firmly connected to the core or the shell part and, in particular, are connected to it in one piece. This enables a particularly simple and cost-effective design with less assembly effort. Surprisingly, it has been found that the magnetic field concentrators do not have to be designed as self-rotating or rotating rolling elements, but that even stationary magnetic field concentrators reliably and reproducibly provide a significant increase in the braking torque that can be generated. The magnetic field concentrators can either be manufactured separately and firmly connected to the star contour or directly to the core or the shell part and, for example, screwed, riveted, soldered, welded or, if necessary, glued or pressed. Amazingly, it is also possible to attach the magnetic field concentrators to the shell part.Overall, a high braking torque is generated in a small (and even smaller) installation space. This allows the overall braking torque to be increased or maintained at the same level in a smaller installation space. New possibilities also open up, as a greater braking torque can be generated in a significantly smaller installation space than before.

[0013] A magnetorheological braking device according to the invention is intended for use in various devices. The magnetorheological braking device can be used in a haptic operating device or configured as such. The magnetorheological braking device can also be used in a device component.

[0014] A star contour within the meaning of the present invention also includes a star-like contour. A star contour within the meaning of the present invention has radially projecting contour elements as magnetic field concentrators. In particular, a local radius at a contour element is larger than at a location adjacent thereto in the circumferential direction. The maximum local radius there is preferably at least 0.1% and in particular at least 0.25% (and preferably more) larger than a minimum local radius adjacent thereto in the circumferential direction. Preferably, a plurality of contour elements are formed over the circumference.

[0015] The core consists of a magnetically (highly) conductive material. The core can, in particular, be made of sintered material (metal). This makes it easier to manufacture the core in the desired shape. The first brake component preferably comprises the core and, in particular, an axle or a shaft, which, in particular, consists at least partially or entirely of a magnetically non-conductive material. The axle (the shaft) and the core are preferably detachably connected to one another.

[0016] The star contour consists at least partially or completely of a magnetically (well) conductive material.

[0017] Preferably, the electrical coil is wound around at least a portion of the core such that a magnetic field of the electrical coil passes through the core and the magnetic field concentrators and through the (axially and / or radially extending) gap into a wall of the casing part.

[0018] Preferably, the magnetic field or field lines run transversely through the first or inner braking component. Extending the first braking component then increases the possible magnetic flux and thus the braking torque while maintaining the same diameter. The core diameter, which is usually not larger due to design constraints, does not limit the magnetic flux.

[0019] In the magnetorheological braking system, the magnetic field concentrators form transmission components. The magnetic field concentrators or the transmission components are at least partially, and in particular substantially completely, surrounded by a magnetorheological medium. A magnetorheological fluid is preferably used as the magnetorheological medium.

[0020] Preferably, several magnetic field concentrators (as transmission components) are distributed around the circumference of the gap. The magnetic field concentrators are not rotatable around themselves, but rotate with the braking component to which they are attached. This results in a relative movement in the gap upon rotation.

[0021] It is possible that, in addition to the magnetic field concentrators or instead of individual segments of the star contour, further transmission components may also be included, e.g., in the form of rolling elements. For the purposes of the present invention, the term "rolling element" refers to a rotating body capable of rolling in the gap on the first or second braking component.

[0022] In preferred embodiments and further developments of the magnetorheological braking device according to the invention, at least one disk contour is formed between the casing part and the core, with a gap section being formed between the disk contour and the casing part. The gap height in the gap section is less variable than the gap height in the gap region of the star contour.

[0023] In simple and particularly preferred embodiments, the gap has specially designed braking areas. In these braking areas, the gap is locally considerably narrower than at other locations. A significant braking area is formed by the gap area at the star contour. Another (e.g., second) braking area can be provided by the gap section at the disk contour.

[0024] Preferably, a minimum gap height at a gap region on the star contour is less than 0.25 mm, 0.20 mm, or 0.15 mm, and preferably less than 0.1 mm, and can be, for example, 0.05 mm + / -25%. Preferably, a gap height at a gap section on a disk contour is less than 0.15 mm, and preferably less than 0.1 mm, and can be, for example, 0.05 mm + / -25%.

[0025] Preferably, the gap section has a substantially constant (and small) gap height over the circumference. Particularly preferably, the disk contour has a cylindrical outer contour. The gap height can, for example, be between 0.03 mm and 0.1 mm, preferably approximately 0.05 mm, at the cylindrical outer contour. This also enables the shell part to be guided by the disk contour.

[0026] In preferred embodiments, the disk contour can have an outwardly projecting outer contour on one axial side. The outer contour can be conical, tapered, bulbous, or rounded. In particular, the outwardly projecting outer contour is rotationally symmetrical. The outwardly projecting outer contour can also be peg-shaped. The outwardly projecting outer contour can provide a reservoir for magnetorheological medium or fluid, which may be required in the region of the gap section (further braking area) during braking to provide magnetic particles.

[0027] Preferably, the gap section has a smaller gap height than a minimum gap height or at least the average gap height of the gap region. A small gap height in the gap section allows for the transmission of a strong magnetic field because the magnetic losses are small.

[0028] Preferably, the star contour guides the casing part in the gap area. Particularly preferably, the disc contour guides the casing part in the gap section and serves as a bearing point for the casing part. This allows for a particularly cost-effective design. Due to the tight tolerances possible there, a magnetorheological braking device and a haptic operating device with a magnetorheological braking device can be provided in a small installation space. This device meets the highest quality standards and is simple and cost-effective to manufacture.

[0029] Preferably, a rolling element section is formed on the core, on which rolling elements are arranged between the core and the shell part. Preferably, the rolling elements can move completely around the core. An outer surface of the core is preferably cylindrical in the rolling element section. The rolling element section forms a further braking area. The rolling elements consist at least partially and at least partially or completely of a magnetically conductive material. In particular, all rolling elements are made of a magnetically conductive material.

[0030] A hybrid solution with a braking area on a star contour in a gap area and with another braking area on a rolling element section offers many advantages.

[0031] In the rolling element section, rolling elements are arranged around the circumference of the core, in particular if an electrical coil is wound around the core (adjacent) to the rolling element section. The star contour is then preferably arranged on one axial side of the electrical coil and the rolling element section with the rolling elements on the other side. The magnetic field of the electrical coil then runs in the core and in the shell part in the axial direction. In the gap region, the field lines of the magnetic field then pass approximately radially from the core through the star contour into the shell part and vice versa. Likewise, the field lines of the magnetic field in the rolling element section pass approximately radially through the rolling elements into the shell part and vice versa.

[0032] The rolling element section allows for the generation of high braking torques, especially at low speeds of the shell. The braking area with the star contour allows for a high static torque and higher torques at higher speeds.

[0033] A radial clearance for a rolling element between the shell part and the core in the rolling element section is preferably greater than a minimum gap height in the gap area on the star contour.

[0034] The radial clearance for a rolling element in the rolling element section is preferably more than twice or at least three times as large or larger than the minimum gap height in the gap area of ​​the star contour. For an effective wedge effect, a gap height in the rolling element section that is greater than the minimum gap height in the gap area of ​​the star contour is useful.

[0035] The rolling elements can be guided via magnetically non-conductive guide elements.

[0036] In all embodiments, it is preferred that the star contour comprises at least one stack of (narrow) star plates. A star plate can, for example, be between 0.5 mm and 5 mm or 10 mm thick. In advantageous simple embodiments, the star plate has a thickness between approximately 1 mm and approximately 3 mm.

[0037] Preferably, at least one stack package comprises star plates that are directly adjacent to one another.

[0038] It is also possible to use a disk contour. A disk contour is formed, in particular, by a stack of (narrow) disk sheets. A disk contour is, in particular, round.

[0039] A stacked package for the star contour and / or a disc contour can also include star sheets and disc sheets. These can also form separate subpackages or be arranged alternately or mixed, for example. Disc sheets, round sheets, and other contour sheets can be used.

[0040] A stacked package can, in particular, comprise or consist of a plurality of stamped parts. Star-shaped sheets and / or disc sheets and / or other contoured sheets are, in particular, stamped parts.

[0041] In a preferred embodiment, the magnetorheological braking device comprises a stationary holder and at least two braking components, one of the two braking components being connected to the holder in a rotationally fixed manner and the two braking components being continuously rotatable relative to one another, a first braking component extending in the axial direction and the second braking component comprising a casing part which extends around the first braking component and is hollow and at least partially cylindrical on the inside, a circumferential gap which is at least partially filled with a magnetorheological medium being formed between the first and the second braking component.The first brake component comprises at least one electrical coil and a core made of a magnetically conductive material and extending in the axial direction, wherein the core comprises a base body and outwardly projecting core contours (as magnetic field concentrators) so that a circumferential gap is produced with a variable gap height (over the circumferential angle), and wherein the electrical coil is wound around at least a section of the core or surrounds the core so that a magnetic field of the electrical coil runs through the core and through at least one outwardly projecting core contour formed thereon (as magnetic field concentrator) and through the (axially or radially) outwardly adjoining gap region into a wall of the casing part.

[0042] In a preferred development of the invention, at least one contour element of a star contour (a magnetic field concentrator) has a cross-sectional area tapering towards the distal end.

[0043] Preferably, at least one magnetic field concentrator is rounded at the distal end.

[0044] It is preferred that the core comprises a plurality of arms and / or the shell part comprises a plurality of arms as magnetic field concentrators, which protrude radially and / or axially. Arms protrude radially outward and / or axially laterally from the core. Arms preferably protrude radially inward and / or axially laterally from the shell part.

[0045] In all embodiments, it is preferred that at least one arm is surrounded by an electrical coil. Particularly preferably, a plurality of arms are each surrounded by an electrical coil.

[0046] Preferably, a radial length of a (radially projecting) arm is smaller than a length of the arm in the axial direction.

[0047] Preferably, at least one electrical coil is wound around the axis and generates a magnetic field in the core substantially in the axial direction (radial coil).

[0048] The electrical coil is preferably accommodated radially (circumferentially) between the core and the shell part.

[0049] In particular, the electrical coil or at least one electrical coil is attached internally to the casing part. The electrical coil is then radially spaced from the core on the first braking component. It is also possible and preferred for at least one electrical coil to be wound around the core. An electrical coil can be wound radially around the core. It is also possible for the electrical coil to be wound axially around the core. In this case, an axis of symmetry of the electrical coil extends transversely to the longitudinal extent of the first braking component.

[0050] In preferred embodiments, at least two star contours are accommodated in the brake housing. The star contours can be identical or, in particular, different.

[0051] Preferably, two star contours are mounted axially spaced from each other. It is also possible for three, four, or more star contours to be mounted axially spaced from each other. Each of these star contours can be identical or have a different shape than the other star contours.

[0052] It is preferred that two star contours are formed identically in pairs.

[0053] At least one star contour is designed in particular as a separate (and preferably hollow) ring flange with radially projecting magnetic field concentrators.

[0054] The magnetic field concentrators can be designed to project radially outward. In this case, the annular flange is preferably firmly (and preferably detachably) connected to the core.

[0055] The magnetic field concentrators can be designed to protrude outwards at an angle. In this case, the annular flange is preferably firmly (and preferably detachably) connected to the core.

[0056] The magnetic field concentrators can be designed to protrude laterally (axially). In this case, the annular flange is preferably firmly (and preferably detachably) connected to the core.

[0057] The magnetic field concentrators can also be designed to project radially inward. In this case, the annular flange is preferably firmly (and preferably detachably) connected to the casing part.

[0058] The magnetic field concentrators can also be designed to protrude diagonally inward. In this case, the annular flange is preferably firmly (and preferably detachably) connected to the casing part.

[0059] The magnetic field concentrators can also be designed to protrude laterally (axially) inward. In this case, the annular flange is preferably firmly (and preferably detachably) connected to the casing part.

[0060] Preferably, at least two star contours have different outer contours. The outer contour can be different, for example, radially inward and / or radially outward and / or on at least one axial side.

[0061] Preferably, at least one star contour has radially outwardly projecting magnetic field concentrators and is magnetically conductively attached to and in particular to the core. For example, the star contour can be secured to the core by a screw connection.

[0062] Preferably, at least one star contour has magnetic field concentrators projecting radially inwards and is magnetically conductively attached to (and in particular in) the casing part.

[0063] Preferably, a magnetic field of the electric coil runs through the core and at least one star contour with the magnetic field concentrators and through the gap and the wall of the casing part.

[0064] If two axially spaced star contours are included, a magnetic field of the electrical coil preferably runs axially through the core, axially through the wall of the shell part and through both star contours with the magnetic field concentrators and the gap between the star contour and the core or shell part.

[0065] In particularly preferred developments, at least one electrical coil is wound around the core in the axial direction and essentially generates a magnetic field in the radial direction (horizontal coil).

[0066] In particular, the magnetic field concentrators form a (in cross-section) star-shaped outer contour.

[0067] Preferably, the casing part has a cylindrical inner surface over at least one axial section.

[0068] Preferably, the magnetic field concentrators extend over at least one angular segment across the outer circumference of the core. In particular, each angular segment is less than 150°.

[0069] Preferably, no magnetic field concentrator is arranged outside the angle segment (or angle segments).

[0070] Preferably, the electrical coil wound axially around the core is mounted on the core outside the angular segment(s). The electrical coil then particularly adjoins the surface.

[0071] Preferably, a maximum (outer) diameter of the electrical coil in a radial direction within a coil plane is larger than a minimum (outer) diameter of the core in a radial direction transverse to, and in particular almost perpendicular to, the coil plane or even perpendicular to, the coil plane. However, the minimum diameter need not be perpendicular to the coil plane.

[0072] The electrical coil preferably extends axially around at least one arm. In particular, a radial gap height between an outer end of an arm and an inner surface of the casing part is smaller than a radial gap dimension between the outer surface of the first brake component adjacent to the arm and the inner surface of the casing part. The surface of the base body can be formed adjacent to the arm. A surface of a potting compound can also be located adjacent to the arm if it is filled in, for example, to reduce the volume for the magnetorheological medium and in particular magnetorheological fluid (MRF).

[0073] Preferably, the second brake component is axially displaceable or displaceably mounted on the first brake component.

[0074] This can also enable volume compensation in the event of temperature changes, for example.

[0075] In preferred embodiments, a click element for actuation is arranged at the distal end of the chamber. The click element preferably provides tactile feedback upon actuation.

[0076] Preferably, an elastic membrane separates the chamber (containing the magnetorheological medium) from the click element. In preferred embodiments, the click element is designed as a snap-action disc. Preferably, a change in the spanned volume of the snap-action disc is adapted to a cross-sectional area of ​​the axis multiplied by an axial offset of the snap-action disc upon actuation. This enables an axial displacement of the shell part relative to the core upon actuation of the click element, requiring no volume compensation or only a minimal volume compensation for the axis entering the chamber.

[0077] In particular, the second brake component is rotatably mounted on the first brake component via two bearing points of different outer diameters in order to effect a volume change in a chamber formed between the first and the second brake component by means of an axial displacement.

[0078] It is preferred that at least one shielding device is included for at least partially shielding the sensor device from a magnetic field of the electrical coil or for shielding other magnetic fields.

[0079] Preferably, the shielding device comprises at least one shielding body surrounding the magnetic ring unit at least in sections, wherein the shielding device comprises at least one separating unit arranged between the shielding body and the magnetic ring unit and / or at least one magnetic decoupling device arranged between the shielding body and the casing part.

[0080] In particular, the separation unit and / or the decoupling device have a magnetic conductivity that is many times lower than that of the shielding body.

[0081] The shielding device may consist of several parts and may comprise, for example, at least one or two axial annular discs and at least one annular sleeve.

[0082] It is preferred that the shielding device and the magnetic ring unit be arranged at a distance from one another. A spacer can be arranged between them. In simple embodiments, a plastic part such as an injection-molded part can be arranged between them and keep the parts at a defined distance from one another.

[0083] Preferably, (at least) one closed (and externally sealed) chamber is formed between the brake components. The second brake component is rotatably received and, in particular, mounted on the first brake component (at a first bearing point) at a first end of the closed chamber, wherein the closed chamber is substantially or completely filled with the magnetorheological medium. The magnetorheological medium can be a magnetorheological fluid containing, for example, carbonyl iron particles. It is also possible to use, for example, (dry or powdered) carbonyl iron powder (without added liquid) as the magnetorheological medium.

[0084] Preferably, the second brake component is axially displaceably received and in particular mounted on the first brake component, so that a volume of the closed chamber changes due to a relative axial displacement of the brake components in order to provide compensation for temperature-related volume changes.

[0085] It is advantageous if the electrical coil is wound axially around the core and essentially generates a magnetic field in the radial direction. This has the advantage that a stronger braking torque can be generated by extending a magnetic field concentrator in the axial direction. At the same time as the magnetic field concentrator is extended, the electrical coil that extends longitudinally of the first braking component can also be extended (in a sensible way). With an electrical coil that is longer in the axial direction, a larger passage area (cross-sectional area through which the magnetic field flows) is available for the magnetic field. Therefore, extending the first braking component in the axial direction also causes the cross-section of the core to be enlarged. As a result, a stronger braking torque can be achieved by extending the first braking component in the axial direction.

[0086] In preferred embodiments, at least some of the magnetic field concentrators consist of a magnetically conductive material. It is also possible for some of the transmission components to consist of a magnetically non-conductive material. If magnetic field concentrators are used which consist of a magnetically conductive material and, at the same time, transmission components are used which consist of a magnetically non-conductive material, the magnetic field is concentrated in the region of the magnetically conductive magnetic field concentrators. This leads to the concentration of the magnetic field (increase in the magnetic field strength) and to a local amplification (magnetic field line concentration). For example, the magnetic field strength in the gap increases from values ​​of less than 350 kA / m to values ​​of up to 1,000 kA / m or more. The (high or) concentrated field strength attracts more carbonyl iron particles from the magnetorheological fluid, resulting in carbonyl iron accumulation (piling). This, in turn, allows the generation of higher shear stresses and thus braking torques.

[0087] Since the relationship between the braking torque that can be generated and the strength of the magnetic field is non-linear, and since the braking torque that can be generated increases disproportionately with increasing magnetic field strength, a significant increase in the braking torque that can be generated can be achieved (with the same installation space / dimensions). It is also possible to select a correspondingly smaller number of magnetic field concentrators.

[0088] If higher braking torques than with the state of the art are required within the given installation space while simultaneously achieving (very) low manufacturing costs, the axial width of the magnetic field concentrator can be very small and designed as a continuous disc (closed contour). For manufacturing cost reasons, the star contour or similarly designed radially or axially projecting arms with interrupting gaps can be dispensed with. The specially selected (very) small width and special contour of the magnetic field concentrator also concentrates the magnetic field and, as previously described, leads to high field strengths in the (annular) gap and thus to the concentration of carbonyl particles (cluster formation). Although the field strengths in the effective gap are not as high as with individual arms due to the larger transition area, they are sufficient for some applications, particularly when there is high cost pressure.

[0089] In all designs, it is not necessary to increase the diameter of the first braking component to increase the braking torque that can be generated. This is very important because many applications do not allow for a larger outer diameter of a braking device, or a larger outer diameter would be a serious competitive disadvantage (e.g., an oversized lateral adjustment dial on a wristwatch, a scroll wheel on a computer mouse, or a thumb roller on a motor vehicle). To amplify / increase the braking torque, the first braking component can be made axially longer, which is either no disadvantage or a minor disadvantage in terms of installation space.

[0090] In all embodiments, it is preferred that the casing part is formed on a rotary knob or rotary wheel or comprises such a part. The rotary part can preferably be formed integrally with the rotary knob or rotary wheel. In such embodiments, it is preferred that the rotary knob or casing part is pot-shaped. The "cover" of the casing part can be integrally connected to a rotary part formed as a sleeve part or can be attached separately to it.

[0091] Preferably, the casing part is made of a magnetically conductive material or comprises a magnetically conductive sleeve part and provides an outer ring for the magnetic field. The magnetic field for generating a braking torque runs through the first braking component and passes through the gap at the magnetic field concentrators, which are magnetically conductive. From the magnetic field concentrators, the magnetic field enters the casing part. There, the magnetic field lines run back before re-entering the first braking component. This creates a closed magnetic circuit or closed magnetic field lines.

[0092] Under the influence of a magnetic field, a wedge effect forms on the magnetic field concentrators upon relative rotation of the first and second braking components relative to one another, as is fundamentally described in WO 2012 / 034697 A1. The disclosure of this document is incorporated in its entirety into this application. The braking torque in the present invention is also generated by the wedge effect or cluster formation on the magnetic field concentrators, even if the magnetic field concentrators cannot rotate around themselves but are attached to the first or second braking component.

[0093] Preferably, at least one radial wall thickness of the casing part or of the sleeve part of the casing part is at least half as large as a gap width of the gap and / or a radial length of a magnetic field concentrator. Preferably, a radial wall thickness (of the sleeve part) of the casing part is greater than 3 / 4 of the gap width of the gap. The radial wall thickness (of the sleeve part) of the casing part can, in particular, also be greater than a radial length of a magnetic field concentrator. A sufficient wall thickness of the casing part made of a magnetically conductive material or of the sleeve part of the rotating part can ensure that the desired field strength of the magnetic field can be generated in the region of the rolling elements in order to be able to generate a high braking torque.

[0094] In all embodiments, it is preferred that the length of the first braking component in the axial direction be greater than the length of a magnetic field concentrator in the axial direction. If the magnetic field concentrator is shorter in the axial direction than the first braking component, this leads to a three-dimensional concentration of the magnetic field in the edge region of the magnetic field concentrator. The magnetic field can practically only pass through the gap in the sections where a magnetic field concentrator is located.

[0095] Preferably, the length of the gap in the axial direction is at least twice as large as the length of a magnetic field concentrator in the axial direction. It is also possible and preferred for two or more magnetic field concentrators to be arranged one behind the other in the axial direction.

[0096] Preferably, the first brake component is substantially cylindrical and comprises an at least partially rotationally symmetrical or cylindrical base body as the core and the electrical coil(s). It is also possible, for example, to include a ball for supporting a rotary knob, which can be centrally located at the distal end to provide a simple and low-friction bearing between the first brake component and the second brake component.

[0097] When using a "horizontal coil," the electrical coil can be wound in axial and transverse grooves of the cylindrical base body (the first brake component). When using a "radial coil," the electrical coil can be wound in a circumferential groove. Preferably, the respective grooves are at least partially filled or overmolded with potting compound. This prevents magnetorheological medium or fluid from entering the area of ​​the coil wires. This could lead to fluid separation.

[0098] Preferably, the holder has a cable feedthrough. Connection cables for the coil and / or sensor cables, etc., can be routed through the holder or the cable feedthrough of the holder. This enables easy assembly and cost-effective production.

[0099] Preferably, the holder has a receptacle for a rotationally fixed connection to the first brake component. The holder can accommodate the first brake component in a force-locking and / or form-locking manner. During operation, the braking torque between the first brake component and the second brake component is dissipated via the holder.

[0100] Preferably, the holder has a cylindrical running surface for a bearing and supports the casing part rotatably on the holder.

[0101] A seal for sealing the gap is preferably arranged on the cylindrical running surface, with the seal in particular being arranged closer to the gap than the bearing. This reliably protects the bearing from the magnetorheological medium. Such a design enables a compact design and reliable operation. The bearing can be, for example, a plain or rolling bearing.

[0102] Preferably, the cylindrical raceway is hardened and / or has a higher surface quality than the radially outer surface of the retainer. This can reduce manufacturing costs.

[0103] In advantageous embodiments, the cylindrical running surface has an outer diameter which is at least 3 mm smaller than an outer diameter of the receptacle of the holder.

[0104] Preferably, the holder is attached to a console or other component.

[0105] In preferred embodiments, a device component comprises at least one magnetorheological braking device, as described above. Such a device component can comprise at least one user interface, a control panel, a display, a touch-sensitive display with or without haptic feedback, and / or at least one sensor.

[0106] It is also possible to use it in a haptic operating device that includes at least one magnetorheological braking device. Preferably, it also includes a user interface, a control panel, a display, a touch-sensitive display with or without haptic feedback, and / or at least one sensor. Such a configuration enables not only operation but also the simultaneous display or output of information during operation. This enables, for example, a control button with a simultaneous output display.

[0107] In all embodiments, it is possible for a pressure-sensitive sensor to be attached to the holder or for such a sensor to be assigned to the holder. For example, a pressure-sensitive sensor can be mounted inside the holder. However, it is also possible for a piezo sensor to be attached to the lower part, etc. The holder can also be constructed in two parts and register an axial displacement of the two parts relative to each other. This can provide haptic feedback.

[0108] In all embodiments, it is preferred that a difference between a clear inner diameter (of the sleeve part) of the casing part and an outer diameter of the first braking component is greater than 3 mm and less than 90 mm. It is also preferred that an outer diameter of the (sleeve part) casing part is between 5 mm or 10 mm and 120 mm. Preferably, a height of the casing part is between 5 mm and 120 mm. In all embodiments, it is preferred that a control device is included which is designed to produce a variable braking effect with the electrical coil.

[0109] Overall, the present invention particularly preferably operates according to the basic principle of wedge clamping, whereby a magnetic field concentrator passes the walls at a certain distance. A magnetic field creates the wedge effect, allowing a high braking torque to be generated.

[0110] The use of a "horizontal coil" also allows for even greater scalability. This makes it possible to generate a scalable and larger braking torque using longer magnetic field concentrators and an axially longer electrical coil. The diameter of the first braking component does not need to be larger to conduct a corresponding magnetic field, because an axial extension of the core also increases the core's surface area (cross-sectional area). If necessary, the axial length can also be significantly reduced if only a relatively low braking torque is required. The installation space can be adapted accordingly.

[0111] A further advantage is that the electrical connection cable for the electric coil can be easily routed out, even for large-scale production. Sealing of the magnetorheological braking system and scaling can be achieved using simple means.

[0112] In principle, longer magnetic field concentrators (in the axial direction) can generate a greater torque from the magnetorheological braking device, as the effective length increases. At the same time, the larger core area ensures that the magnetic field concentrators are always exposed to a corresponding magnetic flux density. The magnetic field strength at the "wedge" on the magnetic field concentrators can be selected higher than in the state of the art. Long magnetic field concentrators or several axially offset magnetic field concentrators can be used, to which a sufficiently strong magnetic field can be applied.

[0113] In particular, when using a "radial coil," the magnetic field generated by the electric coil passes axially through the core, radially through the magnetic field concentrators, and closes axially over the (sleeve part or) the shell part or the outer cylinder. The magnetic field lines close once in one half, e.g., the lower or left, and once in the other half, e.g., the upper or right, of the shell part. In simple designs, the magnetic flux is thus essentially two-dimensional. It does not matter how long or high the magnetic field concentrators are. This allows any scaling in length to be achieved, since the magnetic field transmission area grows accordingly.

[0114] In contrast, with electrical coils wound concentrically around the longitudinal direction of the first braking component ("radial coils"), the cross-sectional area in the core remains constant and can form a bottleneck for the magnetic field as long as the diameter is not changed. In automotive knobs, the core usually has a sufficient diameter to generate the desired braking torque. In these applications, the required diameter of the first braking component is not particularly detrimental to the space requirements, installation dimensions, and weight of the magnetorheological braking system. An advantage is that with the fixed magnetic field concentrators now used, the rotational speed of the rolling elements does not change, which can be disadvantageous.

[0115] If longer magnetic field concentrators are used, the braking effect of a magnetic field concentrator with a long axial extension can be better than that of two shorter ones of the same overall length. This is due, among other things, to the fact that the fluid must be displaced over a longer distance because the edge is further away (hydrodynamic pressure). Two short star contours, in turn, can offer advantages due to their symmetrical design.

[0116] In preferred embodiments, the magnetorheological braking device has a diameter (of the sleeve part) of the casing part of between approximately 5 and 80 mm (+ / - 20%), in preferred embodiments approximately 10 to 40 mm.

[0117] Overall, the invention provides an advantageous magnetorheological braking device ("MRF brake"). The outer diameter of the MRF brake is usually predetermined, especially in haptic applications. Ergonomic guidelines apply here. Therefore, the core cross-section cannot generally be increased so easily, because this also increases the outer diameter (button, thumbwheel, or mouse wheel outer diameter; surface for the fingers). Furthermore, as the outer diameter increases, more locking torque is required, as the torque difference becomes larger. (The finger force, i.e., the (tangential) force between the actuating finger(s) and the braking element or the outer surface of the braking element, must or should remain constant, since, on the one hand, the user can only apply a certain amount of force, and, on the other hand, the necessary forces on the fingers (fingertips) are important for comfort during actuation (operating quality).)

[0118] In preferred embodiments, the electric coil (electric coil) can extend axially. The magnetic field generated by the coil then passes radially through the core, then through the magnetic field concentrators, and closes via the outer cylinder (through the opposite halves in each case). This always remains the same, regardless of the height (or length) of the rolling element or MRF brake.

[0119] The invention achieves the goal of obtaining a simple yet scalable MRF brake with high braking torque and a compact outer diameter.

[0120] Instead of a (cylindrical) coil wire, a flat material or wire with an adapted contour made of copper or another suitable material can also be used.

[0121] The core, the magnetic field concentrators, and the outer cylinder can be made of a simple steel (e.g., S235) with no stringent requirements regarding surface quality and hardness, preferably with good magnetic properties. The surfaces that move relative to each other and generate the braking torque can be rough and / or have a surface structure (e.g., knurls, pyramids, etc.).

[0122] The core, including the electrical coil and potting compound, are preferably centered and fixed in a "holder" (positive or positive connection), and the counter torque is transferred via this to a console, base plate, mounting plate, or housing. The holder preferably has a hole through which the cables are routed. A sealing element (e.g., an O-ring) preferably seals the cable from the holder or the interior, preventing fluid from escaping from the interior via the cable. In addition to the (coil) cable, a temperature sensor cable or other sensor cable can also be routed through this opening.

[0123] The holder can also be made of a different material than the core, rolling element, or outer cylinder. The reduction in the diameter of the holder on the running surface has the advantage of reducing the friction radius for the sealing element, which reduces overall friction. In addition, because of the resulting increased height, a bearing element can be used that has the same bearing outer diameter as the inner diameter of the shell part. This reduces the manufacturing costs of the shell part; no manufacturing step (twist) is required. The preferred rolling element height is between 3 and 6 mm, but can also be 1 or 2 mm. In this range, it is difficult to obtain good bearings or sealing elements if the inner diameter of the holder does not create additional height.

[0124] A decorative or other element, such as a rubberized button, can be attached over the outer cylinder or the casing part.

[0125] Viewed axially from above, a ball or a spherical or ball-like component (can also be a hemisphere) is preferably located between the outer cylinder and the potting compound. This guides the two parts relative to one another. Preferably, the ball is fixed in the potting compound, and the inner axial end face of the outer cylinder rotates relative to it. This creates a simple, low-friction, and cost-effective bearing (bearing point). A conical shape or similar is also possible. However, any other type of bearing can be chosen instead of this type of bearing (e.g., plain or roller bearings).

[0126] Preferably, at least one component through which the magnetic field flows consists at least partially or completely of the material FeSi3P.

[0127] In principle, a star contour can be applied not only to the core but also from the inside into the surrounding shell or sleeve. Such a construction can offer advantages in coil design. It also saves space. In this case, too, various coil variants can be selected. An axial coil or "horizontal coil" is possible. A coil wound around the axis of rotation is also possible. Preferably, no core material is present radially outside the electrical coil, as otherwise the magnetic field could be closed over it, which could cause magnetic losses. It is also conceivable to use more than one "horizontal coil," depending on how they are positioned. A radial coil would also be a good option, as this would simultaneously close the field across all "teeth" or magnetic field concentrators.

[0128] In preferred developments of all embodiments, the maximum torque that can be generated (field strength curve in the effective gap; wedge effect) and / or the reaction time (the time until the torque is applied in the event of sudden current application or current jumps = step response) depends on the selected entry angle at the arms or the respective distal ends of the magnetic field concentrators. The angle generated by the external design of the radial end of the arms and the counter surface and the surface length influence the maximum torque that can be generated and the reaction time when a magnetic field or the field strength is generated in the effective gap. Flatter (smaller) entry angles and / or longer surfaces increase the achievable torque. Larger (steeper) entry angles and / or shorter surfaces shorten the reaction time. Flatter angles are, for example, an angle between 0° and 10°, or preferably between 10° and 20°. Larger angles are between 20° and 30° or between 30 and 45°.It's also possible to create negative angles, meaning they're curved inward. For example, -5°.

[0129] It can also be advantageous to combine different contours / angles / shapes. One tooth of the star contour then generates higher torque at low speeds, the other tooth at medium speeds, and the third tooth at high speeds. This creates a braking device that generates high torque across the entire speed range.

[0130] A disc or annular flange without a star contour is easier to manufacture and can therefore be manufactured more cost-effectively. However, the braking performance (braking torque) is not the same. Depending on the installation space requirements, manufacturing costs, and potential braking torque, either a star contour (for higher power densities) or a continuous disc can be used for lower power density requirements but higher manufacturing costs. The disc can be rotationally symmetrical.

[0131] In addition to the different braking torques of the various contours, different response times must also be taken into account. The more magnetizable material is used, the longer the magnetic field takes to magnetize the entire material and deliver its full power (inductance). This means that using less material shortens the actuator's response time.

[0132] Therefore, an additional criterion when selecting the contour is the response / switching times required for the application. These requirements vary depending on the customer and the intended use. Very fine ticks / ripples (changing torque) require very short response times (a few milliseconds).

[0133] Typical dimensions or values ​​of the contour elements or "teeth" of star contours are 5% to 15% of the total diameter. For example, in a specific design, the maximum diameter of the star contour (with outwardly projecting contour elements or "teeth") is 36 mm, and the height of a contour element or magnetic field concentrator or teeth is approximately 2.5 mm. The minimum diameter is thus 31 mm. This corresponds to a relative size of 7% of the diameter. A star contour with typical deviations from the disk shape would be, for example, depressions of 5-10% of the total diameter.

[0134] A preferred range for the depth of the depressions is between 0.25% and 25%, particularly between 0.5% and 10%.

[0135] Manufacturing costs are lower with smaller tooth heights. Therefore, it may be advantageous to use only very small deviations from the round disc.

[0136] A star contour with smaller deviations from the disc shape would be, for example, small indentations of 1-3% of the total diameter.

[0137] The width of the star contour can also vary. A preferred design is between 1 mm and 25 mm. Specifically, widths of 3 mm and 6 mm have been successfully tested.

[0138] Preferably, in particular, the haptic operating device according to the invention is used to generate a high power density of a braking device or braking unit with magnetorheological fluid, this being achieved by contour elements which concentrate the magnetic field.

[0139] In particular, the carbonyl iron particle is attracted from the environment and concentrated in the magnetic field transition region.

[0140] The applicant reserves the right to claim a method for generating an increased power density of a braking device with two braking components and with magnetorheological fluid and at least one electrical coil, wherein the increased power density is generated by a fixed braking component and a braking component that moves rotationally around the central axis of the fixed braking component and is in direct magnetic contact with the latter, wherein contour elements are arranged on one of the two braking components and are in particular connected thereto in a rotationally fixed manner, which concentrate the magnetic field.

[0141] Another method is used to generate a high power density with a braking device with magnetorheological fluid and at least one electric coil, whereby this is generated by a fixed element and an element that moves rotatively around the central axis of the fixed element and is in direct magnetic contact with it, which concentrate the magnetic field.

[0142] In particular, carbonyl iron particles are attracted from the environment and concentrated in the magnetic field transition region.

[0143] Preferably, the brake component that rotates around the central axis is one-piece.

[0144] Further advantages and features of the present invention will become apparent from the embodiments which are explained below with reference to the accompanying figures.

[0145] The figures show: Figures 1a-1f show schematic three-dimensional views of device components with a magnetorheological braking device; Figures 2a-2c show schematic cross-sections of another device component with a magnetorheological braking device; Figures 3a-3b show a magnetorheological braking device with a wedge damper with two star contours, each on one side of the electrical coil; Figure 4 show another cross-section of a magnetorheological braking device; Figure 5 show further schematic cross-sections of a magnetorheological braking device in section; Figure 6 show another schematic cross-section of a magnetorheological braking device; Figures 7a-7e show another device component; Figures 8a-8c show possible torque curves over the angle of rotation of a magnetorheological braking device of a device component according to the invention; Figures 9a-e show schematic views of yet another device component with a magnetorheological braking device;Figures 10 show a cross-section of another device component with a magnetorheological braking device; and Figures 11a-c show schematic views of another device component with a magnetorheological braking device; Figures 11a-c show schematic views of another device component with a magnetorheological braking device; Figure 12 shows torque curves of an electric motor and a magnetorheological braking device over the electrically applied power; Figure 13 shows the resulting braking torque curves of a magnetorheological braking device for two different current intensity curves over time; and Figure 14 shows a highly schematic circuit for controlling the electrical coil.

[0146] Figures 1a to 1f show several device components 200 according to the invention in which the magnetorheological braking device 1 can be used. The device components 200 are each designed as a haptic operating device 100.

[0147] Figure 1a shows a haptic control button 101. The control button is attached to the console 50. The control button 101 is operated via the casing part 13 or sleeve part 13e. The user interface 43 can also be used to transmit information.

[0148] In Figure 1b The device component 200 is depicted as a thumb roller 102 with a haptic operating device 100. The thumb roller 102 is preferably used, for example, in steering wheels. However, the thumb roller is not limited to this application. The thumb roller 102 can generally also be used with any other finger, depending on the installation situation.

[0149] In Figure 1c and Figure 1d The device component 200 according to the invention is designed as a computer mouse 103. The haptic operating device 100 is housed in the mouse wheel 106. The magnetorheological braking device 1 can be used to control haptic feedback.

[0150] Figure 1d shows a joystick 104 as a haptic operating device 100, in which a magnetorheological braking device 1 is housed. Furthermore, the magnetorheological braking device 100 according to the invention can also preferably be used in a gamepad 105 to provide the player with haptic feedback depending on the game situation.

[0151] In these embodiments, the magnetorheological braking device 1 has a casing part 13 or rotating part or sleeve part 13e, which is rotatably mounted. The torque required to rotate the casing part 13 or rotating part 13 is adjustable.

[0152] A user interface 43 can be arranged on the top side of the magnetorheological braking device 1. Such a user interface 43 can be designed, for example, as a display device or as a touch-sensitive input option (touchpad, motion and gesture control, image recognition, etc.).

[0153] A haptic operating device 100 can be used, for example, to operate machines, medical devices, or for use in and for a motor vehicle. In a vehicle, the haptic operating device 100 can be used, for example, to operate air conditioning systems, radios, entertainment systems, navigation, distance control, driver assistance, seat adjustment, and infotainment systems. It can also be used on other devices or other devices.

[0154] Figure 2ashows a device component 200 according to the invention in section with a magnetorheological braking device 1 according to the invention. The transverse grooves 32 can be seen, in which the electrical coil 26 of the magnetic field generating device 113 is wound at the axial ends of the core 21. Connecting cables 45 are led out downwards here. The magnetic field extends within the core 21 perpendicular to the coil plane 26c in the radial direction 26d. In the axial direction, a potting compound 28 is provided at both ends. In the area of ​​the cable feedthrough 35, a separate seal is provided, for example, via the O-ring shown or the like.

[0155] The wall thickness of the cylindrical shell part here is calculated from the distance between the outer diameter 13b and the inner diameter 13a of the shell part 13.

[0156] A length or height 13c of the magnetic field concentrator 80 and the casing part 13 or the sleeve part 13e or the second brake component 3 in the axial direction 20 is preferably between 1 mm and 100 mm or between 5 mm and 90 mm. A coating 49 can be applied to the outside of the second brake component 3, so that the external appearance of the rotary knob 23 is essentially determined by the surface of the coating 49.

[0157] The material of the sleeve part 13e or the casing part 13 as a whole is magnetically conductive and serves to close the magnetic circuit. A wall thickness 13d of the sleeve part 13e is preferably at least half the radial extent of the magnetic field concentrators 80. The casing part 13 forms an outer ring 24.

[0158] The diameter 36a of the receptacle 36 is preferably considerably larger than the diameter 37a of the cylindrical raceway 37. This reduces friction at the seal 38. Furthermore, standardized bearings can be used.

[0159] A (flanged) sensor (rotary encoder, angle encoder) detects the speed (angle of rotation) of the control unit.

[0160] It is also possible to construct the core 21 and the holder 4 in two parts. Preferably, the separation runs along the Figure 2drawn center line, resulting in a left and right (core) half. The two core halves can be spaced apart from each other by a magnetically non-conductive element (e.g., seal). Preferably, the potting compound volume 28 is then part of the core half(s), resulting in a semicircular element with a circumferential groove on the separating surface for the electric coil 26. Furthermore, the receptacle 36 is preferably also divided into two halves. A receptacle half can also form a part with a core half (be designed as a single piece), or a core half can be designed as a single piece with a complete receptacle unit 36.

[0161] Here, the haptic operating device 100 is mounted on one side with the magnetorheological braking device 1. The second braking component 3 is only received at the first end of the closed chamber 110 at an end section 121 of the first braking component 2, i.e., the second braking component 3 is only mounted at the first bearing point 112 by the bearing 30. If the volume within the closed chamber changes, the second braking component 3 can move back and forth slightly. Here, it is again assumed that the first braking component 2 is stationary. In this case, a portion of the diameter 116 of the first braking component 2 extends or retracts at the first bearing point 112. The volume 114 of the closed chamber 110 changes. Advantageously, the system is practically always at ambient pressure within the given range of motion. Additional loading of the seal 38 is prevented.

[0162] Figures 2b and 2cshow various schematic cross sections of the magnetorheological braking device 1, which is used in the device components 200 according to Figure 2a and can also be used in other embodiments.

[0163] The inner brake component 2 is stationary and is surrounded by the continuously rotating brake component 3. The second brake component 3 has a casing part 13 that rotates around the first brake component and is hollow and cylindrical on the inside. The gap 5 extending between the first and second brake components 2, 3 can be seen. The gap 5 is here at least partially and in particular completely filled with a magnetorheological medium 6.

[0164] The first brake component 2 has the core 21 made of a magnetically conductive material, which extends in the axial direction 20, and an electrical coil 26 wound around the core 21 in the axial direction 20 and defines a coil plane 26c. The magnetic field 8 of the electrical coil 26 extends transversely to the axial direction 20 through the first brake component 2 and the core 21.

[0165] It is clearly evident that a maximum outer diameter 26a of the electrical coil 26 in a radial direction 26d within the coil plane 26c is greater than a minimum outer diameter 21b of the core 21 in a radial direction 25 transverse and, for example, perpendicular to the coil plane 26c.

[0166] The magnetic field concentrators 80 project radially outward from the base body of the core 21. The course of the magnetic field 8 is shown as an example in Figure 2b marked.

[0167] The electrical coil is arranged outside the angle segments 61 and 62 (cf. Figure 2c ). Outside the angle segments 61 and 62 there are no magnetic field concentrators 80.

[0168] The cores 21 have outwardly projecting arms 83 as magnetic field concentrators 80, which extend radially outward from the base body 33. In Figures 2b and 2c the chamber 110 between the core 21 and the shell part 13 is completely filled with MRF.

[0169] The maximum outer diameter 26a of the coil 26 is larger than the minimum core diameter 21b. The radial extent of the gap 5 varies around the circumference. At the outer ends of the magnetic field concentrators 80, there is only a small radial gap height 85, while a radial gap dimension 87 between the braking component 2 and the braking component 3 is considerably larger at other locations.

[0170] However, the radial gap height 85 between an outer end of an arm 83 and an inner surface 67 of the casing part 13 is considerably smaller than a radial gap dimension 87 between the outer surface 86 (i.e. the core 21 directly or also a surface of a potting compound 28 on the core) of the first brake component 2 next to the arm 83 and the inner surface 67 of the casing part 13.

[0171] Figure 2c shows a variant of Figure 2b, in which, to reduce the MRF volume, the chamber 100 is filled with potting compound 28 over a cylindrical section. This reduces the required volume of MRF. The star contour 40 or the magnetic field concentrators 80 protrude (radially) into the gap 5, so that a circumferential gap region 40d with a variable gap height 40c is created in the area of ​​the star contour 40. The radial gap dimension 87 (maximum gap height) is significantly reduced, but remains considerably (at least a factor of 2 or 3 or 5 or 10) larger than the (minimum) (radial) gap height 85. This ensures that the described wedge effect occurs. The MRF particles interlink in the acute-angled areas and form a type of wedge, which leads to a considerable braking torque. In the Figures 2b and 2c the magnetic field concentrators 80 form a kind of radial arms 83.

[0172] Figures 3a and 3bshow another magnetorheological braking device 1 for a haptic operating device 100. The magnetorheological braking device 1 comprises a brake housing 1a, which here ( Fig. 3b ) essentially consists of the two ends or covers 14, 15 and the casing part 13.

[0173] The first brake component 2 comprises the axle 12, which is sealed on at least one side and extends out of the brake housing 1a. The second brake component 3 comprises the brake housing 1a. The control button 101 is housed or formed on the outside of the brake housing 1a.

[0174] The axis 12 may also have a through opening and, for example, a longitudinal bore.

[0175] Typically, the first brake component 2 is mounted in a rotationally fixed manner with a holder 4 (not visible here) on a bracket 50 or on other parts or components. Then, at least the casing part 13 forms a rotatable part of an operating knob 101 or the like. The torque required to rotate the casing part 13 is adjustable. However, it is also possible for the brake housing 1a to be mounted in a rotationally fixed manner and for the axle 12 to be rotatable.

[0176] In Fig. 3a The magnetorheological braking device 1 is shown without an outer brake housing 1a and without a casing part 13. Here, two star contours 40 are included, which are mounted on the core 21 at a distance from one another along the axis 12 in the axial direction 20. Each star contour 40 is formed as a separate part and is clamped onto the core 21 via a separate screw nut 40b. The star contour can be cylindrical or conical on the inside.

[0177] If necessary, the core 21 and the star contours 40 can also have non-circular outer and inner contours that are adapted to one another in order to ensure a rotationally fixed reception of the star contour 40 on the core 21. In Fig. 3a The top left shows a view of a star contour 40, which has a through-hole inside. The inner contour can be cylindrical (shown in solid lines) or non-circular (polygon, polygon, oval, etc.) (shown in dashed lines).

[0178] The magnetic field concentrators 80 are formed radially outward on the star contour 40. A recess 87a is formed between each individual magnetic field concentrator 80. Here, all magnetic field concentrators 80 of a star contour 40 are formed integrally on the star contour 40. Rotatable rollers or other rotating bodies are not present as magnetic field concentrators 80 or otherwise.

[0179] The two star contours 40 of the magnetorheological braking device 1 according to Fig. 3a can be of identical design. However, it is also possible that different star contours 40 are arranged at the right and left ends. In particular, the magnetic field concentrators (which in all embodiments can also be referred to as contour elements) can also be shaped differently at the star contours 40 on the right and left (cf. the upper part of Fig. 3a (each individually depicted star contour). It is also possible to include two (or three) different star contours at one or each end. The contour elements can have different geometric designs and different dimensions.

[0180] In cross section according to Fig. 3bIt can be seen that the axle 12 (also called the shaft) is sealed from the brake housing 1a by seals 38. The coil holder 26b, on which the electrical coil 26 is wound, is accommodated between the two star contours 40. The electrical coil 26 can be immediately and directly adjacent to the casing part 13 and is then held magnetically insulated from the core 21. Or the electrical coil 26 can be immediately and directly adjacent to the core 21 and is then held magnetically insulated from the casing part 13.

[0181] A magnetic field line 8 is shown as an example. The magnetic field runs essentially axially between the star contours 40 through the shell part 13 and, in the region of the two star contours 40, passes approximately radially through the gap 5 there and is concentrated by the magnetic field concentrators 80, resulting in a wedge effect in the region of the magnetic field concentrators 80. The magnetic field is closed within the core 21 in the axial direction 20.

[0182] In principle, the magnetorheological braking device 1 comprises a wedge bearing with two star contours 40. At its center is a magnetically conductive axle or shaft 12, around which an electrical coil 26 is wound radially. The electrical coil 26 generates a magnetic field 8, which is amplified by the shaft 12 as the core 21. The magnetic field lines 8 lead through the star contour 40 on one side, across the magnetically conductive outer wall in the casing part 13, and further to the second star contour 40 on the other side, via which the field lines return to the axle or shaft 12. In this way, the magnetic field 8 is utilized very efficiently. In the gap 5 between the star contour 40 and the outer wall (casing part 13), MRF serves as a damping medium.

[0183] Various star contours can be mounted in this configuration. Shaft 12 has a conical mount onto which the ring flanges 40a, each with its own (e.g., milled) star contours 40, are slid. A threaded nut 40b behind the ring flange 40a then presses the ring flange 40a onto shaft 12 when tightened.

[0184] Figure 4 shows two schematic cross sections of other embodiments with a (cylindrical) base body 33. The star contour with the magnetic field concentrators 80 are formed by individual outwardly projecting radial arms 83, wherein the radial arms 83 are formed integrally with the core 21 and consist of a material with good magnetic conductivity.

[0185] Here, each individual arm 83 is wrapped by an electrical coil 26 of the magnetic field generating device 113. The electrical coils 26 are preferably controlled jointly, but can also be controlled differently and / or individually. The distal and, in this case, radially outer ends 82 of the arms 83 can be wedge-shaped, rounded, or even angular. Accordingly, for arms 83 projecting radially inward as magnetic field concentrators 81, the radially inner end, as the distal end 82, can be wedge-shaped, rounded, or even angular. The shape influences the maximum torque that can be generated and the reaction time.

[0186] The arm height 84 is considerably greater (factor 10, 50, 100 and much more) than the radial gap height 85 between an outer end of an arm 83 and an inner surface 67 of the shell part 13.

[0187] However, the radial gap height 85 between an outer end of an arm 83 and an inner surface 67 of the casing part 13 is considerably smaller than a radial gap dimension 87 between the outer surface 86 (core 21 or also surface of a potting compound 28) of the first brake component 2 adjacent to the arm 83 and the inner surface 67 of the casing part 13. Preferably, the ratio of the radial gap dimension 87 to the radial gap height 85 is greater than 2, 5, or 10 or more. A certain enlargement is important for wedge formation. The star contour 40 or the magnetic field concentrators 80 protrude(s) radially into the gap 5, so that a circumferential gap region 40d with a variable gap height 40c results in the area of ​​the star contour 40.

[0188] In Figure 5Three different outer contours of a core 21 are depicted on a shell part 13 formed with a cylindrical cavity. The magnetic field concentrators 80 projecting radially outward at the star contours 40 can be of different shapes. The outwardly projecting magnetic field concentrators 80 form a circumferential gap region 40d at the gap 5 with a gap height 40c that varies over the circumference, so that the magnetic field 8 is concentrated in the region of the magnetic field concentrators 80 when it passes from the core 21 into the shell part 13. The star contours 40 are formed by annular flanges with magnetic field concentrators 80 projecting outward therefrom. The annular flanges are each hollow and can be non-circular on the inside to ensure a rotationally fixed connection with the core, which is then also non-circular there.

[0189] The left figure shows purely schematically Figure 5A dashed variant in which the magnetic field concentrators 81 protrude inward and the core 21 is located inside. This creates a reversed image. By shaping the ends of the magnetic field concentrators 80 and 81, different properties can be achieved. This allows the focus to be placed on a higher braking torque or a faster reaction time. The gap area 40d with variable gap height is visible in all three variants, but is only marked with a reference symbol in the right-hand variant.

[0190] Figure 6shows a schematic variant with a central cylindrical core 21 and a shell part 13, from which magnetic field concentrators 81 periodically protrude radially inward. A highly schematic magnetic field line 8 is drawn, which radially passes through the gap 5 between the core 21 and a magnetic field concentrator 81. At the constriction, a cluster of particles 19 of the MRF interlink in the gap 6 filled with the medium 6 and forms a wedge (cluster) in an acute-angled region 10, which generates a high braking torque.

[0191] In addition to the variant shown, in which the electrical coil is wound around the core in the axial direction, a variant is also possible in which the electrical coil 26 is wound radially around the axis of rotation (2).

[0192] Figures 7a to 7eshow a further embodiment of a device component 200, which has a magnetorheological braking device 1 and comprises braking components 2 and 3. A "horizontal or axial coil" is again used, in which the electrical coil 26 is wound around the core 21 in the axial direction 20 and again has a maximum radial coil diameter 26a that is larger than a minimum core diameter 21b of the core 21. Here, too, radially outwardly projecting magnetic field concentrators 80 are provided, which concentrate the magnetic field in the thin radial gap and ensure the wedge effect. This is not conventional shear damping because the gap height of the gap 5 changes massively over the circumference. Horizontal lines are drawn here, which show the radial starting point for the magnetic field concentrators 80. Outside the magnetic field concentrators 80, the gap height is much larger (here a factor > 50 or 100 or 1000).

[0193] Here, the device component 200 is designed as a haptic operating device 100 and, in detail, as an operating button 101. The second brake component 3 is received at the first end 111 of the closed chamber 110 at the bearing point 112. Furthermore, the second brake component 3 is received at the second bearing point 118 at the second end 115 of the closed chamber 110 on the first brake component 2. The bearing absorbs forces in the (global) radial direction 122, while the brake components 2, 3 remain axially displaceable relative to one another.

[0194] Here, the bearing is realized by means of an axle stub 119 with a diameter of 117 at the second bearing point 118. The sealing ring 46 prevents the magnetorheological medium 6 from flowing into the area behind the axle stub 119.

[0195] The diameter 117 at the second bearing point 118 is significantly smaller than the diameter 116 at the first bearing point 112. This also allows for a volume change in the event of an axial displacement. Temperature-induced volume changes and volume changes caused by leaks can be compensated for. For this purpose, the first brake component 2 is axially displaced relative to the second brake component 3. To reduce the throttling effect across the gap 5 in the event of an axial displacement, a compensation channel 120 can be provided, which connects the two areas near the bearing points 112, 118.

[0196] In addition, a sensor device 70 is also present here for detecting an angular position of the haptic operating device 100. The magnetic field sensor 72 is integrated into the fixed receptacle 4 or the first brake component 2. The cable 45 of the magnetic field sensor 72, i.e., the sensor line 73, is routed to the outside through the cable duct 35 at the receptacle 36.

[0197] The first axle part or the holder 4 of the brake component 2 can, as in Figures 7b and 7c As shown, it is preferably designed in two parts. This simplifies the installation of the electrical lines, and in particular the sensor line 73, within the first brake component 2. The cables can be routed through the open cable entry 35.

[0198] In Figure 7dthe sensor device 70 is shown again in detail. The first brake component 2 and the second brake component 3, which is designed here as a rotated part, are only indicated (dashed lines). The sensor device 70 is supported in a magnetically decoupled manner via the decoupling device 78 on the rotatable second brake component 3. The shielding device 75 here consists of three shielding bodies 76, which reduce the scattering of the magnetic field 8 of the electrical coil 26. In addition, a separation unit 77 is also present for magnetic separation. The magnetic ring unit 71 is used to measure the orientation or the angle of rotation of the magnetorheological brake device 1. The magnetic field sensor 72 is arranged within the first brake component 2. Small relative axial displacements can also be used to detect, for example, the pressing down of an operating button 101, cf. Figure 7e .

[0199] Due to an axial displacement, the received signal 68 of the sensor device changes as shown in Figure 8. Figure 8 shows the curve of the amplitude 69 of the signal 68 detected by the magnetic field sensor 72 as a function of the axial displacement of the brake components 2, 3 (horizontal axis). An axial displacement of the magnetic field sensor 72 relative to the magnetic ring unit 71 changes the amplitude 69 of the detected signal 68. An axial displacement or pressing down of a control button 101 or a lateral displacement, e.g., of a mouse wheel 106 or other components, can be detected.

[0200] The same sensor 72 can also be used to detect the angle of rotation, whereby the direction of the magnetic field 8 is determined to detect the angle of rotation. The intensity determines the axial position. Therefore, a change in signal 68 can be used to infer that the button 74 has been actuated. This is advantageous because a single (multidimensional) Hall sensor can be used to determine the angular position and the axial position.

[0201] In the Figures 8a, 8b and 8c Possible design variants for controlling a dynamically generated magnetic field or a dynamically generated braking torque depending on the angle of rotation are shown.

[0202] Figure 8ashows a variant in which a rotary knob is used as a haptic operating aid. The rotational resistance is shown plotted against the angle of rotation. A left end stop 228 and a right end stop 229 can be generated with the control 27. Upon further rotation of the rotary knob 23, a strong magnetic field or stop torque 238 is generated there, causing the rotary knob 23 to offer high resistance to a rotary movement. The user receives haptic feedback of an end stop.

[0203] A grid pattern of the rotary movement can be created (ripples / ticks). This can be used, for example, to navigate through a graphical menu and select menu items. A first grid point 226 is provided directly next to the left end stop 228, which, for example, corresponds to a first menu item during operation. If the next menu item is to be selected, the rotary knob 100 must be turned clockwise. To do this, the dynamically generated higher magnetic field or cogging torque 239 or its friction torque must be overcome before the next grid point 226 is reached. Figure 8aFor a certain angular range, a constant magnetic field is generated at the grid points 226 and at the intermediate areas, which is considerably lower at the grid points than in the intermediate areas and again considerably lower than at the stops 228, 229. A set torque or the constructively resulting basic torque 240 can act at the grid points 226.

[0204] An angular distance of 237 between individual grid points can be changed dynamically and is adapted to the number of available grid points or menu items.

[0205] Figure 8bshows a variant in which the magnetic field does not rise abruptly towards the end stops 228, 229, but rather takes a steep course. Furthermore, ramp-like gradients of the magnetic field are provided at the grid points 226 on both sides of rotation, whereby the rotational resistance increases in the corresponding directions of rotation. Here, with the same operating device 100, only three grid points 226 are provided, the angular spacing 237 of which is greater than in the example according to Figure 8a .

[0206] Figure 8c shows a variant in which there is a lower rotational resistance between individual grid points 226 and an increased magnetic field 239 is generated only directly adjacent to the grid points 226 in order to enable engagement at the individual grid points 226 and at the same time to provide only a low rotational resistance between individual grid points.

[0207] In principle, a mixture of operating modes and magnetic field characteristics of the Figures 8a, 8b and 8c For example, different submenus can be used to set the magnetic field profile differently (torque versus angle).

[0208] In all cases it is also possible that, for example, with a ripple (raster), switching is not done as before between less and more current with the same polarity (e.g. +0.2 to +0.8A = ripple), but alternately with changed polarity, ie from +0.2 to +0.8A and then the next ripple with -0.2A to -0.8A and then the next torque peak from +0.2 to +0.8A etc.

[0209] In all cases it is also possible that the operating modes of the Figures 8a, 8b and 8cA combination of operating modes can be selected using voice commands. The user selects a function (volume, station selection, etc.) via voice input (with local or remote voice recognition, e.g., via Alexa, Amazon Echo, Siri, Google Voice Input, etc.). The magnetorheological braking system then provides the corresponding operating mode (volume = step with increasing braking torque for increasing volume; radio station selection = step with different increments, with a slight braking torque in between until the station is found).

[0210] The preferably low-alloy steel can retain a residual magnetic field. The steel is preferably demagnetized regularly or as needed (e.g., by a special alternating field).

[0211] The preferred material for the components through which the magnetic field flows is FeSi3P (silicon steel) or a similar material.

[0212] In all cases, voice or sound control can be implemented. Voice control allows adaptive control of the braking system.

[0213] If the rotating unit is not rotating, i.e., the angle is constant, the current is preferably continuously reduced over time. The current can also be varied depending on the speed (angular speed of the rotating unit).

[0214] The Figures 9a to 9e show various views of a haptic operating device 100 with a magnetorheological braking device 1, which can be used as an operating button 101. The haptic operating device 100 comprises a holder 4, which can be fastened, for example, to a console 50 via a nut 51.

[0215] The magnetorheological braking device 1 has two braking components 2, 3, of which the inner braking component 2 in Figure 9ais not visible. The inner brake component 2 is connected to the holder 4. The holder 4 and the inner brake component 2 are stationary here. The other brake component 3 comprises the casing part 13 and is rotatably mounted on the first brake component 2.

[0216] The haptic operating device 100 is of compact construction and has, inside the shielding device 75, which has a two-part shielding body 76 as a shielding housing, a sensor device 70 (not visible here) for detecting the rotational position and the axial position of the casing part 13. The casing part 13 is connected to a left cover 14 and a right cover 15 via pins 16 in order to seal an inner closed chamber 110.

[0217] Figure 9bshows a possible variant with the jacket part 13 removed. The coil 26 covers the underlying core 21. At the distal and here left end, a disc contour 41 is recorded on the core 21. At the proximal and here right end, a star contour is recorded.

[0218] At the star contour or by the star contour 40, a gap area 40d (as a braking area) is defined or formed between the star contour 40 and the casing part 13, in which a variable gap height 40c is present all around.

[0219] At the disc contour 41 at the distal end or by the disc contour 41, a gap section 41a (as a braking area) is defined or formed between the disc contour 41 and the casing part 13, in which a constant gap height 41b is present all around.

[0220] The gap region 40d and the gap section 41a form the braking regions of the magnetorheological braking device. The magnetic field of the electric coil 26 extends axially through the core 21 on the inside and axially through the casing part 13 on the outside, and radially from the star contour 40 into the casing part or from the disk contour into the casing part at the braking regions.

[0221] The mixed "hybrid solution" allows braking torque advantages to be used during start-up and also at high speeds.

[0222] This here in Figures 9b and 9c The casing part, not shown, is connected to the covers 14, 15 via pins or similar fastening means or the like. O-rings 39 or the like can be provided as seals.

[0223] In the illustration according to Figure 9c Two star contours are axially mounted at the ends of the core. This allows for high maximum torques.

[0224] Both in Figure 9b as well as in Figure 9cThe star contours and the disk contour are each designed as a stacked package 44. A stacked package 44 for a star contour comprises several star plates 40f, which are arranged in a row to adjust the thickness. The individual star plates are, in particular, stamped parts that can be manufactured cost-effectively.

[0225] A stacked package 44 for a disk contour 41 comprises a plurality of disk sheets 46, which are preferably also formed as stamped parts and are also arranged in series to adjust the thickness. Stacked packages 44 can also comprise mixed sheets, e.g., alternating star sheets and disk sheets 46 (in groups or individually). Such a mixed stacked package 44 also forms a star contour overall.

[0226] The haptic operating device 100 comprises a sensor device 70 (not visible here), which is shielded by the shielding device 75 with the shielding body 76 designed as a housing. A magnetic ring unit 71 is arranged inside the shielding device 75, the signal of which is detected by the sensor device 70.

[0227] A membrane 31 and a click element 29 can be seen at the distal end. The click element 29 can be designed, for example, as a snap-action disc and serves for axial actuation. When actuated, the snap-action disc produces a noise. The actuation can be felt.

[0228] Figure 9d shows the haptic control device 100 from Figure 9c, with the core removed. The core is axially connected to the star contours (or optionally) disc contours or mixed stacked packages and is axially pressed thereto via pins 16 or the like. It is also possible for the star contours and disc contours to be plugged onto the core.

[0229] This type of star contour 40 allows for easy contacting of the electrical coil. Since the star contour 40 does not rotate, the cable 45 for contacting can be fed radially in the outer area at the radial height of the electrical coil 26 to a radial recess 52 or a through hole. This allows for convenient contacting of the electrical coil 26.

[0230] Figure 9eshows a highly schematic representation of the haptic operating device with a snap-action disc 29 in two different positions, with the unactuated position shown on the left and the actuated position shown on the right. In the left illustration, the snap-action disc is curved outward and downward, and is guided by the guide 29a in the core 21 (but not supported, thus creating virtually no friction).

[0231] The volume of the spanned triangle 29b is in the right half of the Figure 9ecan be seen. The volume 29b is approximately determined by the hatched three-dimensional cone. If the haptic control button 100 is actuated and the snap-action disc 29 is deflected from the rest position and transferred into a linear position within a plane, the casing part 13 is displaced axially downwards relative to the first braking component 2. As a result, an axial section 22 of the axle or of the first braking component 2 is immersed in the interior of the casing part 13. The volume change 29b of the snap-action disc 29 is preferably dimensioned such that it essentially corresponds to the immersed volume of the first braking component 2. The immersed volume is calculated from the axial path 22 multiplied by the cross-sectional area of ​​the first braking component 2 on the axle 12. By bringing the area 29b as close to this as possible, a pressure build-up inside the chamber 110 can be minimized or prevented.Volume compensation can also be provided by a membrane 31 as shown in . Figures 9b and 9c can be seen.

[0232] Figure 10 shows a schematic cross-section of another haptic operating device 100, wherein the first braking component 2 is fixed to a holder 4, for example, with grub screws. This embodiment also provides two braking regions, with a star contour 40 formed on the gap region 40d. Rolling elements 11 or rotating bodies are accommodated on the circumference of the core 21 in the braking gap section 11a and can rotate completely around the core 21. The rolling elements 11 are guided via holders 11f.

[0233] The star contour 40 has an outwardly projecting outer contour 47 at its axially outer end, which is configured, for example, as a cone here, but can also be configured as a pin. This leaves a reservoir 34 for magnetorheological particles in each of the corner regions to ensure a sufficient supply of magnetorheological particles to the braking areas. In particular, carbonyl iron particles are attracted from the environment and concentrated in the magnetic field transition region.

[0234] Screws 48 are used to fill or empty the chamber 110.

[0235] In the Figures 11a to 11cPossible cross-sections of a haptic operating device 100 are shown. The haptic operating device 100 has a magnetorheological braking device 1. The braking component 2, which extends in the axial direction and to which the core 21 is fastened, is received on the holder 4. The braking component 2 comprises a shaft or axle 12 to which the core 21 is fastened. The core 21 is made of a magnetically conductive material, and the axle here is made of a magnetically non-conductive material, so that the magnetic field sensor 72 inside the axle 12 can detect the magnetic field and its orientation inside the axle 12.

[0236] The core 21 is radially surrounded by the casing part 13 as the outer or second braking component 3.

[0237] The magnetically conductive core 21 is surrounded by an electrical coil 26 wound around the core 21. The electrical coil extends over an axial width 26e. At the end of the core 21 facing the holder 4, a star contour 40 is formed, which is applied to the core 21 here and, for example, pressed on or axially attached thereto. The star contour 40 has a hollow-cylindrical stacking package 44 for this purpose. The receptacle on the core can also be non-circular. The stacking package 44 can also be axially connected to the core 21.

[0238] The disc pack 44 consists of a plurality of thin star-shaped sheets 40f. Here, the star-shaped sheets 40f are each formed as a stamped part and can be punched, for example, from a magnetically conductive sheet 1 mm, 2 mm, 3 mm, or 4 mm thick (or slightly more, less, or something in between). This allows the required number of star-shaped sheets to be punched out easily and cost-effectively to create the desired thickness of the star contour 40.

[0239] The individual star plates 40f are pressed together and applied to the core 21 or, for example, screwed or pressed thereto. A gap area 40d remains in the area of ​​the star contour 40 with a variable gap height 40c between the outer diameter of the star contour 40 and the inner circumference of the shell part 13. The axial width 40d of the star contour 40 is determined here by the number of star plates 40f and can be selected larger or smaller than shown.

[0240] The star contour 40 is here axially directly adjacent to the electrical coil 26, which is accommodated in a coil holder 26b and is completely sealed radially outwards by a casting compound 28.

[0241] The star contour 40 is connected to the core 21 and to the stationary brake component 2 and does not rotate during operation. This allows the formation of a hole or recess 52 for the passage of the cables 45 for the electrical connection of the electric coil 26. The electric coil 26 can thus be connected easily, cost-effectively, and quickly.

[0242] The star contour 40 is formed here at the proximal end, i.e., at the end of the core 21 facing the holder 4. A rolling element section 11a is formed at the distal end, i.e., at the other end of the core 21. The rolling element section 11a extends across the axial width of the rolling elements 11. There, the rolling elements 11 are distributed around the circumference of the core 21. The rolling elements 11 form magnetic field concentrators 80 for locally amplifying the magnetic field as it passes through the rolling element section 11a.

[0243] The rolling element section 11a allows a very high braking torque to be achieved, particularly at low speeds of the casing part 13. Through the gap area 40d in the area of ​​the star contour 40, a strong magnetic field can be transmitted from the core 21 into the casing part 13, since the minimum gap height is considerably smaller than the radial clearance 11c in the area of ​​the rolling element section 11a. This allows for the generation of high torque, which is particularly possible even at higher speeds. This allows for high torque to be provided across the entire speed range.

[0244] The axial width of the rolling element section 11a and the width of the gap area 40d of the star contour 40 are approximately equal here (+ / -25%) and together slightly shorter than the electrical coil 26. Overall, a very compact design is achieved.

[0245] The casing part 13 is in Figure 11asurrounded by a cover 49 as a rotary knob 23. The rotary knob 23 is at least partially transparent so that it can be illuminated by the lighting means 18, for example, LEDs. The lighting can be controlled depending on the situation or also independently of the situation.

[0246] At the front end, the closed chamber 110 inside the casing part 13 is closed by a front cover 14, through which the braking component 2 passes. A seal 38 serves for sealing. At the rear or distal end, the chamber 110 is initially delimited by an elastic membrane 31, to which a click element 29, here designed as a snap-action disc, is connected on the outside.

[0247] By axially actuating the rotary knob 23, the snap disc or click element is actuated, and the casing part 13 is moved slightly to the left. This axial movement can be detected by the sensor device 70 with the magnetic field sensor 72 inside the holder or the first brake component 2, which is radially surrounded by a magnetic ring unit 71. The magnetic field sensor 72 is designed in particular as a Hall sensor 72 and detects the orientation of the radial magnetic field relative to the magnetic field sensor 72. This can be used to detect an angular position of the casing part 13 relative to the core 21. An axial adjustment of the casing part 13 by actuating the click element 29 leads to a relative axial offset between the magnetic ring unit 71 and the magnetic field sensor 72, which causes a change in the intensity of the detected signal. This can be used to detect actuation of the click element.

[0248] Figure 11bshows a slightly different representation of a haptic operating device 100 with a magnetorheological braking device, whereby in contrast to Figure 11a the cover 49 or the rotary knob 23 was omitted.

[0249] A key difference between the Figures 11a and 11b is that in Figure 11b At the distal end of the casing part 13, a gap section 41a with a disc contour 41 is provided. A star contour 40 is also formed at the proximal end of the casing part 13. The disc contour enables higher braking torques when stationary and at high speeds.

[0250] In this embodiment, for example, a bearing for supporting the casing part 13 relative to the brake component 2 can be provided outside the chamber 110 between the seal 38 and the sensor device 70. However, it is also possible here for the bearing to be provided at one end only via the seal 38 and the star contour 40 and at the other distal end only via the disc contour 41.

[0251] Examples are shown in Figure 11b some magnetic field lines 8, which show the largely axial course of the magnetic field lines in the core 21 and in the shell part 13. Furthermore, it can also be seen that in the braking areas at the gap region 40d and the gap section 41a, an (approximately) radial passage of the magnetic field lines 8 occurs.

[0252] The magnetic field sensor 72 is mounted on a sensor board 79 and can be contacted via the contact pins 79a. The electrical coil 26 is also supplied with power via this pin.

[0253] At least in the area of ​​the sensor device 70 and the magnetic field sensor 72, the inner brake component 2 is preferably made of a material with little or no magnetic conductivity to ensure the most undisturbed detection possible of the orientation and intensity of the magnetic field of the magnetic ring unit 71 inside the axle 12 or the first brake component 2. There, the sensor device 70 is housed in a particularly protected manner (protection against water and dust).

[0254] In Figure 11b an O-ring 39 can be seen, which seals the cover 14 against the casing part 13.

[0255] Figure 11cshows a schematic cross-section of the rolling element section 11a. The core 21 can be seen inside, around which the rolling elements 11 are schematically arranged. The rolling elements are in turn surrounded by the casing part 13. The rolling elements each have a diameter 11d. A radial gap height 11b is slightly larger than the diameter 11d. This results in a radial clearance 11c as the difference between the gap height 11b and the diameter 11d. The radial clearance 11c is generally divided relatively evenly between the radial inside and radial outside.

[0256] A magnetorheological medium comprising magnetorheological particles 19 is accommodated in the chamber 110. A gap 5 is provided in the chamber 110 between the brake components 2 and 3. The chamber 110 is here at least partially filled with a magnetorheological medium 6. The medium is preferably a magnetorheological fluid, which, for example, comprises an oil as a carrier fluid in which ferromagnetic particles 19 are present. Glycol, grease, water, and viscous substances can also be used as the carrier medium, without being limited thereto. The carrier medium can also be gaseous, or the carrier medium can be omitted (vacuum). In this case, only particles 19 that can be influenced by the magnetic field are filled into the chamber 110.

[0257] The ferromagnetic particles 19 are preferably carbonyl iron powder, with the particle size distribution depending on the specific application. Specifically, a particle size distribution between one and ten micrometers is preferred, although larger particles of twenty, thirty, forty, and fifty micrometers are also possible. Depending on the application, the particle size can be significantly larger, even reaching into the millimeter range (particle spheres). The particles can also have a special coating / shell (titanium coating, ceramic, carbon shell, etc.) to better withstand the high compressive loads that may occur depending on the application. For this application, the magnetorheological particles can be made not only from carbonyl iron powder (pure iron), but also, for example, from special iron (harder steel).

[0258] It is possible to fill the gap 5 or chamber 110 with particles that can only be influenced by the magnetic field, with air or an inert gas being added if necessary. If, for example, only air or another gas is used, various solids can be mixed in to improve certain properties. For example, graphite powder can be added to reduce friction between the carbonyl iron particles, since graphite has a lubricating effect. The particles can in particular be coated with PTFE. A coating with PTFE or a comparable coating prevents the particles from clumping together and forming larger clusters. Such larger clusters do not disintegrate easily or, in some cases, do not disintegrate at all. Alternatively, the disk bodies or roller bodies can also be coated with PTFE to reduce friction.When using MRF without oil or other liquid as a carrier medium, it is important to ensure that no water condenses in the braking chamber (MR chamber or MRF chamber). For example, silica gel or another desiccant can be mixed in to absorb water, thus removing moisture from its surroundings.

[0259] The magnetorheological particles 19 interlink when a magnetic field is applied, as in Figure 11c shown very schematically. This creates a wedge effect, which leads to a significant increase in braking torque at low and medium speeds.

[0260] For a more detailed explanation of this effect, please refer to the Figure 4 Reference is made to the applicant's international application WO 2018 / 215350 A1, which is fully incorporated into the scope of disclosure of this application in an adapted manner with regard to the explanation of the effect.

[0261] Figure 12shows a schematic representation of two generated braking torque curves, with the generated braking torque (normalized and therefore dimensionless here - Y-axis) plotted against the electrically applied power (normalized and therefore dimensionless here - X-axis). The curve for a BLDC motor ("brushless direct current motor") is shown on the left, and the curve for a magnetorheological braking device is shown on the right. It can be seen that for the same braking torque, the electric motor requires considerably more power than the magnetorheological braking device. For a braking torque of "14", the electric motor requires more than "130" of standardized power, while the magnetorheological braking device requires (significantly) less than "0.3". The power consumption ratio is greater than 100:1 and is approximately 500:1 here.

[0262] Magnetorheological clutches and brakes have the advantage, among other things, that they require very little power for coupling or damping movements, are quiet, generate little heat, and respond very quickly (~ms), etc. The low power requirement is particularly advantageous for battery-powered components such as electric vehicles, where the power consumption of all components automatically has a significant impact on the vehicle's range. However, power consumption is also an issue for vehicles with combustion engines or electrical devices in general.

[0263] Figure 13 shows the resulting braking torque curves of a magnetorheological braking device 1 for two different current curves (Y-axis) over time (X-axis). The dashed curve in the upper half of the figure represents the conventional curve, in which the current is increased directly to the desired current.

[0264] Here, for example, at time 0.1 seconds, the current is increased from 0 amperes to 2 amperes. The resulting curve of the braking torque or coupling intensity is shown in the lower half of Figure 13 shown in dashed lines. The transferable braking torque increases in the dashed curve from the starting time at 0.1 seconds within about 25 milliseconds (time 0.125 seconds) to a read value of about 1.25 (normalized to, for example, an average value or a standard unit) and reaches asymptotically (almost) the set limit value of about 1.5 after about 75 milliseconds (time 0.175 seconds).

[0265] However, if the current is tripled at the beginning of the clutch engagement or the start of the braking or damping process, for example, to 6 amps, as shown by the solid lines, the braking torque increases considerably, reaching its final value of 1.5 after only about 10 milliseconds. The "current boost" with increased current is only activated for about 10 ms. After that, as the upper solid curve shows, the current is reduced to 2 amps. The brief increase in current ("current boost") allows for a significantly faster adjustment (provision) of the clutch, damping, or braking torque. This is very advantageous in several respects, as it allows for a quick stop and a more direct haptic feeling (feedback). In reality, the difference between the two curves is very noticeable.

[0266] Figure 14shows a schematic of a circuit for quickly controlling the electrical coil 26. The electrical coil 26 (magnetic coil) can be controlled here, for example, by an H-circuit. This is only indicated here by switches. A voltage source 35a with a lower voltage of, for example, 12V (or 3V or 6V; a suitable voltage depending on the application), used in normal operation or continuous operation, supplies the voltage for normal operation. For voltage peaks, a voltage source 35b with a higher voltage of, for example, 18V or 24V (or, for example, 6V or 12V) is connected in via a switch. The voltage source 35a with the lower voltage is then temporarily disconnected. After the maximum current is reached, the voltage source 35b with the higher voltage is disconnected from the circuit and the electrical coil 26 and the voltage source 35a with the lower voltage is reconnected.The switches can be any electrical components that are particularly capable of coupling and decoupling in the millisecond range.

[0267] This allows the current in the electrical coil 26 to reach the desired value more quickly. In one specific case, the desired current is reached within 10 ms instead of 40 ms. The switching between the voltages can be accomplished via an electrical circuit.

[0268] A combination of voltage and current is also possible. Voltages of over 24 volts and much higher (e.g., > 100 volts) are also possible. List of reference symbols:

[0269] 1 Magnetorheological braking system 26c Coil level 26d radial direction to 26c 1a brake housing 26e axial width 2 Brake component 27 Control device 3 Brake component 28 Potting compound 4 holder 29 Snap dome 5 gap, channel 29a guide 6 medium 29b volume 8 Field 30 warehouse 10 acute-angled area 31 membrane 11 Rolling elements 32 transverse groove 11a Rolling element section 33 (cylindrical) 11b Gap height of 5b Basic body 11c radial clearance at 5b 35 Cable entry 11d Diameter of 11 36 Recording 11f bracket 36a Outer diameter 12 axis 37 cylindrical running surface 13 Coat part 37a Outer diameter 13a diameter 38 seal 13b Diameter13c Height 39 O-ring 13d Wall thickness 40 star contour 13e sleeve part 40a Ring flange 14 Diploma 40b Mother 15 end, lid 40c Gap height 16 Pen 40d gap area 18 Light bulbs 40e minimum gap height 19 magnetic particles 40f Star sheet 20 axial direction 41 Disc contour 21 core 41a split section 21b minimum diameter 41b Gap height 22 Hub 42 disc body 23 rotary knob 43 User interface 24 Outer ring 44 Stack package 25 radial direction 45 Cable 26 Sink 46 disc sheet 26a maximum diameter 47 protruding outer contour 26b spool holder 48 Filling screw 49 coating 102 Thumb roller 50 console 103 computer mouse 61 Angle segment 104 joystick 62 Angle segment 105 Gamepad 67 Inner surface of 13 106 Mouse wheel 68 signal 110 closed chamber 69 amplitude 111 first end of 110 70 Sensor device 112 first storage location 71 Magnetic ring unit 113 Magnetic field generating device 72 Magnetic field sensor 73 Sensor cable 114 Volume of 110 74 button 115 second end of the closed chamber 75 Shielding device 76 Shielding body 116 Diameter of first bearing point 77 Separation unit 78 Decoupling device 117 Diameter of second bearing point 79 Sensor board 79a Contact pin 118 second storage location 80 Magnetic field concentrator 119 axle stub 81 Magnetic field concentrator 120 compensation channel 82 distal end 121 End section of 2 83 arm 122 radial direction (global) 84 radial length of the arm 200 Device component 85 Gap height 226 Grid point 86 outer surface 228 End stop 87 Gap size 229 End stop 87a Deepening 237 Angular distance 100 Haptic control device 238 Stop torque 239 Raster moment 101 Control head 240 Fundamental moment

Claims

1. A magnetorheological braking device (1) with a brake housing (1a) and a fixed holder (4) and with at least two brake components (2, 3), wherein one of the two brake components (2, 3) is connected torque-proof to the holder (4) and wherein the two brake components (2, 3) are continuously rotatable relative to one another, wherein a first brake component (2) extends in the axial direction (20) and a core (21) extending in the axial direction (20) comprises a magnetically conductive material and wherein the second brake component (3) comprises a hollow casing part (13) extending around the first brake component (2), wherein an circumferential gap (5) filled at least partially with a magnetorheological medium (6) is formed between the first and the second brake component (2, 3), characterised in that at least one electrical coil (26) is accommodated in the brake housing (1a), wherein at least one star contour (40) with magnetic field concentrators (80, 81) formed thereon, which project into the gap (5), is arranged between the casing part (13) and the core (21), so that a circumferential gap region (40d) with variable gap height (40c) results in the region of the star contour (40), and that the star contour (40) comprises at least one stack package (44) of star plates (40f).

2. The magnetorheological braking device (1) according to claim 1, wherein at least one disc contour (41) is formed between the casing part (13) and the core (21), wherein a gap section (41a) is formed between the disc contour (41) and the casing part (13), and wherein a gap height (41b) in the gap section (41a) is less variable than the gap height (40c) in the gap region (40d) of the star contour (40).

3. The magnetorheological braking device (1) according to the preceding claim, wherein the gap section (41a) has an essentially constant gap height (41b) over the circumference and wherein the disc contour (41) has a cylindrical outer contour.

4. The magnetorheological braking device (1) according to any one of the three preceding claims, wherein the disc contour (41) has an outwardly projecting outer contour (47) on at least one axial side.

5. The magnetorheological braking device (1) according to any one of the three preceding claims, wherein the gap section (41a) has a smaller gap height (41b) than a minimum gap height (40e) of the gap region (40d).

6. The magnetorheological braking device (1) according to any one of the preceding claims, wherein at least one stacking package (44) comprises star plates (40f) directly adjacent to one another.

7. The magnetorheological braking device (1) according to any one of the preceding claims, wherein a stacking package (44) comprises star plates (40f) and disc plates (46).

8. The magnetorheological braking device (1) according to any one of the preceding claims, wherein the stacking package (44) comprises a plurality of stamped parts or consists of stamped parts.

9. The magnetorheological braking device (1) according to any one of the preceding claims, wherein at least one magnetic field concentrator (80, 81) has a cross-sectional area tapering towards the distal end or is formed rounded off at the distal end (82).

10. The magnetorheological braking device (1) according to any one of the preceding claims, wherein the core (21) comprises a plurality of arms (83) and / or the casing part (13) comprises a plurality of arms (83) as magnetic field concentrators (80, 81), which project radially.

11. The magnetorheological braking device (1) according to any one of the preceding claims, wherein at least one electrical coil (26) is wound around the axis (12) and essentially produces a magnetic field in the axial direction (20) or wherein at least one electrical coil (26) is wound around the core (21) in the axial direction (20) and essentially produces a magnetic field (8) in the radial direction (26d).

12. The magnetorheological braking device (1) according to the preceding claim, wherein the electrical coil (26) is accommodated radially between the core (21) and the casing part (13) and wherein the electrical coil (26) is internally fastened to the casing part (13) or wound around the core (21).

13. The magnetorheological braking device (1) according to any one of the preceding claims, wherein at least two star contours (40) are accommodated in the brake housing (1a) axially spaced apart from one another and wherein, in particular, at least two star contours (40) have a different outer contour.

14. The magnetorheological braking device (1) according to any one of the preceding claims, wherein a closed chamber (110) is formed between the brake components (2, 3), and wherein the second brake component (3) is held rotatable on the first brake component (2) at a first end (111) of the closed chamber (110), wherein the closed chamber (110) is substantially filled with the magnetorheological medium (6).

15. A device component (200) with a magnetorheological braking device (1) according to any one of the preceding claims.