DE102020128305A1 - Magnetoelastic sensor unit and arrangement with the magnetoelastic sensor unit - Google Patents

Abstract

A magnetoelastic sensor unit 4 is used to detect a force and/or torque acting on a component 2, 3, with a primary sensor component 5, with the primary sensor component 5 having a magnetic region M which, when the component 2, 4 is acted upon by the force and/or or the torque causes a magnetic field change in a magnetic field, with a secondary sensor component 6 for detecting the magnetic field change in the magnetic field occurring under the action of the force and/or the torque on the component 2, 4, the primary sensor component 5 and the secondary sensor component 6 being relative to a main axis H are arranged coaxially to one another and can be rotated relative to one another in a direction of rotation, with at least one radially extending radial section 15a, with radial section 15a being firmly connected to one of the two sensor components 5, 6, with primary sensor component 5 and secondary sensor component 6 being connected by the radial section 15a to e are kept spaced from each other in a radial direction RR and are secured relative to each other in an axial direction AR.

Description

The invention relates to a magnetoelastic sensor unit for detecting a force and/or torque acting on a component, having the features of the preamble of claim 1. The invention also relates to an arrangement with the magnetoelastic sensor unit.

Magnetoelastic sensors are known which are used to detect a torque on the basis of magnetostriction. Such a sensor system usually includes a primary sensor and a secondary sensor. The primary sensor is a magnetized component, such as a shaft, magnetized with a revolving, self-contained magnetic field. The secondary sensor is designed as a magnetic field sensor and is used to detect a magnetic field change in the magnetic field, which occurs as a function of the magnetoelastic effect under the action of a force (inverse magnetostriction). Since the change in the magnetic field is proportional to the force applied, a connection with the torque can be established.

The pamphlet DE 102017200528 A1 discloses a drive train of a vehicle with at least one drive motor and a transmission, wherein at least one torque sensor is provided for activation, the torque sensor for detecting the torque present in each case being integrated into a transmission component. In particular, a magnetoelastic sensor for detecting the torque applied to the transmission component is provided as an integrated torque sensor.

The invention is based on the object of creating an improved sensor unit which is distinguished by a compact configuration and simplified assembly. Furthermore, it is the object of the invention to propose an arrangement with the magnetoelastic sensor unit.

This object is achieved by a sensor unit having the features of claim 1 and an arrangement having the features of claim 10. Preferred or advantageous embodiments of the invention result from the dependent claims, the following description and the attached figures.

The invention relates to a magnetoelastic sensor unit which is designed and/or suitable for detecting a force and/or torque acting on a component. In particular, the sensor unit is designed as a magnetoelastic, preferably inverse magnetostrictive, torque and/or force sensor.

The component can be designed as a movable, in particular rotating, or stationary component which is and/or can be acted upon by the force and/or a torque. In principle, the component can be designed as any component of a machine, system, vehicle or the like, which must be monitored during operation with regard to its load. For example, the rotating component as a shaft, a bearing, a transmission element, z. B. gear, or the like may be formed. For example, the stationary component can be designed as a housing, an axle, a frame or the like. Optionally, the sensor unit includes the component.

The sensor unit has a primary sensor component with a magnet area. In particular, the magnetic area is designed as a magnetizable and/or magnetized area of the primary sensor component. Alternatively, the primary sensor component itself can be magnetized. When the component is subjected to the force and/or the torque, the magnetic area causes a change in the magnetic field. In particular, when the component is subjected to the force and/or the torque, a magnetic field component occurs outside and/or inside the component, the size of which depends on the applied torque and causes a measurable change in the magnetic field. In particular, the magnetic area has a permanent and/or self-contained magnetic field, which in the unloaded state of the component does not emerge from the surface of the primary sensor component, or only emerges as a small stray field. Preferably, the magnetic area and/or the magnetic field is designed to run all the way around or at least in sections to run around a main axis of the sensor unit and/or a component axis of the primary sensor component.

The sensor device has a secondary sensor component, which is designed and/or suitable for detecting the change in the magnetic field occurring under the action of the force and/or the torque on the component. In particular, the secondary sensor component serves to detect the force or the torque on the basis of the magneto-elastic effect. The magnetoelastic effect refers in particular to the interaction between the force or torque acting on the component on the one hand and the change in the magnetic field on the other. In detail, the change in the magnetic field is caused by the fact that the so-called white areas in the material of the primary sensor component shift due to the load on the component. Normally, these areas are oriented so differently that no magnetization of the material can be seen macroscopically. Depending on the acting Force or torque change the Weiss areas in magnitude and direction, so that a change in the magnetization that can be detected by the secondary sensor component takes place or an external, detectable magnetic field is generated. In particular, the secondary sensor component is designed as at least one magnetic field sensor, which can in particular detect a flux density and/or magnetic field strength and/or a magnetic field direction and/or a change in it. Alternatively, the secondary sensor component has at least one primary coil and at least one secondary coil, the magnetic field being generated via the primary coil and being detectable via the secondary coil. In particular, the magnetic field changes due to a change in permeability in the material, the change in permeability being proportional to the stresses in the material and thus to the torque.

The primary sensor component and the secondary sensor component are arranged coaxially and/or concentrically with respect to the main axis of the sensor unit and can be rotated relative to one another in a circumferential direction about the main axis. In particular, the primary sensor component and the secondary sensor component are arranged without contact and/or at a distance from one another in the axial and radial direction in relation to the main axis. The main axis is preferably defined by a longitudinal axis and/or axis of rotation of the primary sensor component and/or the secondary sensor component and/or the component. A radial direction, an axial direction and a circumferential direction are defined by the main axis, which are each aligned perpendicularly to one another.

In the context of the invention, it is proposed that the sensor unit has at least or precisely one radially extending radial section. The function of the radial section is to keep the primary sensor component and the secondary sensor component spaced apart from one another in the radial direction and to secure them relative to one another in the axial direction. The radial section is firmly connected, in particular non-rotatably, to one of the two sensor components. In particular, the radial section extends parallel to and/or in the same direction as a radial plane defined by the main axis. The radial section is preferably arranged coaxially and/or concentrically to the main axis and/or is designed to be uninterrupted in the direction of rotation. In particular, the radial section is designed as a ring-shaped and/or annular disk-shaped element or section.

The advantage of the invention is that the at least one radial section allows the two sensor components to be assembled in a particularly stable and precisely positioned manner. In addition, the radial section ensures that the two sensor components are kept spaced apart from one another, in particular in the radial direction, thus ensuring relative rotation between the two sensor components. Furthermore, the installation of the sensor unit can be simplified by the radial section, since the two sensor components are secured in a defined relative position to one another by the radial section, which corresponds to an intended installation position.

In a preferred embodiment it is provided that the sensor unit has at least or precisely one further radial section. The at least or exactly two radial sections are arranged at a distance from one another in the axial direction on one of the sensor components, with the other sensor component being arranged in the axial direction between the at least or exactly two radial sections, so that the primary sensor component and the secondary sensor component form one by the at least or exactly two radial sections common unit are held together. In particular, the radial sections each define an axial limit or an axial end stop for the sensor component arranged between them, so that the sensor component is held captively between each radial section both in the axial direction and in an axial opposite direction. The sensor component arranged between the radial sections is preferably arranged at an axial distance from the respective adjacent radial sections and at a radial distance from the sensor component carrying the radial sections. For example, the distance in the axial and/or radial direction is more than 0.1 mm, preferably more than 0.5 mm, in particular more than 1 mm. A gap preferably remains between the primary sensor component and the secondary sensor component, which allows rotation between the two sensor components in the installed state. Optionally, at least one of the radial sections can have an internal recess which is designed and/or suitable for axially and radially accommodating the intermediate sensor component. In particular, the sensor unit can have more than two of the radial sections if, for example, several of the sensor components are arranged one behind the other in the axial direction. By arranging the radial sections on one sensor component and accommodating the other sensor component between the two radial sections, an easy-to-handle sensor unit is proposed, which is also held together to form a unit when it is removed.

In a further specific embodiment, it is provided that one sensor component has an outer cylinder or is designed as one and that the other sensor component has an inner cylinder cylinder has or is designed as this, wherein the inner cylinder is arranged with the radial distance in the outer cylinder. In particular, the outer cylinder is designed as a hollow cylinder, for example a cylinder sleeve. In particular, the inner cylinder is designed either as a hollow cylinder, for example a further cylinder sleeve, or as a solid cylinder. The at least one radial section, but preferably both radial sections, are arranged on an inner circumference of the outer cylinder in order to secure the inner cylinder in the axial direction. In particular, the inner cylinder has a smaller extent in the axial direction than the outer cylinder, so that the inner cylinder is and/or can be arranged between the two radial sections with the axial spacing. Alternatively, the at least one radial section, but preferably both radial sections, are arranged on an outer circumference of the inner cylinder in order to secure the outer cylinder in the axial direction. In particular, the outer cylinder has a smaller extent in the axial direction than the inner cylinder, so that the outer cylinder is and/or can be arranged between the two radial sections with the axial spacing. A very compact and space-saving sensor unit is proposed by the two cylinders.

In principle, the at least one radial section can be designed as a separate component which is connected to the inner cylinder or the outer cylinder in a form-fitting and/or force-fitting and/or cohesive manner. For example, the at least one radial section is designed as a flanged wheel for this purpose. Alternatively, the radial section and the inner cylinder or the outer cylinder are made from a common material section, e.g. For example, the at least one radial section is formed for this purpose by a radial edging of the inner cylinder. Alternatively, at least one of the radial sections can be detachably arranged on the inner cylinder or the outer cylinder, with the sensor unit being able to be opened by removing one of the radial sections in order to insert or remove the other sensor component, e.g. for maintenance.

Optionally, in addition, the secondary sensor component has a cylindrical carrier element which is connected to the inner cylinder in a rotationally fixed manner, the inner cylinder being connected to the carrier element at least in a rotationally fixed manner. The carrier element can be designed as a solid cylinder or as a partially or completely designed hollow cylinder. Designed as a solid cylinder, the carrier element can have at least one connection interface for connecting a retaining rod. Designed as a partially or fully formed hollow cylinder, the retaining element can be partially or fully attached to the retaining rod.

In a further embodiment it is provided that the at least one radial section is arranged on an axial end area of the inner cylinder or the outer cylinder in order to increase a torque and/or force transmission area. The at least one radial section is preferably arranged on the component to which the torque and/or force is applied, in particular the primary sensor component, in order to reinforce its torque and/or force transmission range. The torque and/or force transmission area is to be understood as an area of the primary sensor component into which the torque and/or the force is introduced or discharged. One radial section is preferably arranged on one axial end area and the other radial section is arranged on the other axial end area of the inner or outer cylinder. Thus, the inner and outer cylinder has two radial sections, which are arranged opposite one another in the axial direction in each case at an axial end area. A sensor unit is thus proposed which is characterized by a particularly robust and stable arrangement of the inner and outer cylinder in an assembled and loaded state.

In a further specification, it is provided that the inner cylinder has an inner mounting surface which is designed and/or suitable for mounting on an inner component, and/or that the outer cylinder has an outer mounting surface which is designed and/or suitable for mounting on an outer component is. In particular, the inner cylinder is connected to the inner component via the inner assembly surface and/or the outer cylinder is connected to the outer component via the outer assembly surface in a force-fitting and/or positive and/or material-to-material manner. The mounting surfaces preferably remain unlocked in the removed state of the sensor unit and are then closed at the installation site by the inner and the outer component to which the mounting surfaces are attached. In particular, the inner or the outer component can be designed as the component to which the torque and/or force is applied. In this case, the torque and/or force transmission area is formed or co-formed by the assembly inner surface or assembly outer surface, so that the mechanical stresses caused by the torque or force are transmitted to the primary sensor designed as an inner or outer cylinder. Preferably, the inner assembly surface is formed by an inner surface of the cylinder jacket of the inner cylinder and/or the outer assembly surface is formed by an outer cylinder jacket surface of the outer cylinder. That Depending on the design, the outer component can, for example, be in the form of a hollow shaft or a cylindrical housing section. Alternatively, depending on the design, the inner component can be in the form of a shaft, in particular a solid shaft, or the retaining rod. Provision can furthermore be made for the inner cylinder to be connected to the carrier element via the inner mounting surface. A sensor unit is thus proposed which is characterized by a particularly simple assembly of the inner and outer cylinder, while at the same time the primary and secondary sensor component can be designed in a simple and therefore cost-effective manner.

Alternatively or optionally in addition, the inner or outer cylinder of the primary sensor component is carried by two webs, the webs having a circular mounting surface for mounting on the inner or outer component. Furthermore, the primary sensor component can have a stiffening ring which runs axially between the two webs.

In a further specific implementation, it is provided that the sensor unit has at least or precisely one sealing device which is designed and/or suitable for sealing a measuring space formed between the primary sensor component and the secondary sensor component. A permanent sealing of the measuring chamber is preferably realized by the sealing device, which is present both stationary and dynamic, that is to say with a relative rotation of the two sensor components. In particular, the measuring space is delimited in the axial direction by the radial section(s) and in the radial direction is delimited on the one hand by the inner cylinder and on the other hand by the outer cylinder. The sealing device is arranged at a free radial end of the radial section. When fixed to the radial section, the sealing device preferably rests in a sealing manner either on the outer circumference of the inner cylinder and/or the inner component or alternatively on the inner circumference of the outer cylinder and/or the outer component. The sealing device can be formed, for example, by a radial shaft sealing ring or by a sealing lip made of a flexible material, so that a reliable sealing function is also provided when the components are rotating. Alternatively, the seal may be formed as a brush seal, the core of which is highly flexible and made up of a multiplicity of wires or fibers. These lie flexibly on the surface to be sealed, so that a dynamic and static sealing function is given. A sensor unit is thus proposed which is characterized by improved protection of the sensor components against environmental influences such as dirt, oil or moisture. This results in a more precise determination of the torque as well as an increase in the service life of the sensors used.

In an alternative or optionally supplementary development, it is provided that the sensor unit has at least one bearing device which is designed and/or suitable for the rotatable bearing of the sensor components relative to one another. In particular, the bearing device is used for the radial and/or axial bearing of the sensor unit. The bearing device is arranged at a free radial end of the radial section. The bearing device can be embodied as a roller bearing, with the bearing device having at least one inner ring and at least one outer ring for this purpose, with a plurality of rolling elements being arranged in a rolling manner between the inner ring and the outer ring. When the radial section is fixed to the inner cylinder, the inner ring can be connected in a rotationally fixed manner to the radial section and the outer ring can be connected in a rotationally fixed manner to the outer cylinder or the outer component. When the radial section is fixed to the outer cylinder, the outer ring can be connected to the radial section in a rotationally fixed manner and the inner ring can be connected to the inner cylinder or the inner component in a rotationally fixed manner. Alternatively, however, the rolling elements can also roll directly on the radial section and/or the inner or outer cylinder or the inner or outer component. Alternatively, the bearing device can be designed as a plain bearing, with the bearing device being defined by at least one sliding surface. In particular, the sliding surface can be provided by a plain bearing sleeve or can be arranged directly on the radial section or its bearing partner. In particular, the bearing device and the sealing device can exist side by side, with the bearing device and the sealing device being arranged together on the radial section and/or the sealing device being integrated into the bearing device. A sensor unit is thus proposed which is characterized by a particularly low-friction and wear-free relative rotation of the two sensor components. The bearing device also ensures that the two sensor components are supported on one another in a particularly stable manner and the measuring accuracy can thus be increased.

In a further embodiment it is provided that the secondary sensor component has a measuring direction directed in the axial direction in relation to the main axis. The radial section is formed from a non-magnetically conductive or a poorly magnetically conductive material when the measuring direction of the secondary sensor component is axial to the main axis and/or horizontal is directed towards the primary sensor component or its magnetic area. In particular, “poorly magnetically conductive” should be understood to mean that the material of the radial section has a significantly poorer magnetizability than the material of the primary sensor component or its magnetic area. For example, the material of the radial section is made of plastic or a non-ferromagnetic material. In particular, the primary sensor component has two magnetic tracks. To measure the torque, magnetic fields must be measured which move in the range of the earth's magnetic field, approx. 50µT. In order to achieve compensation for the earth's magnetic field in the measurement signal, the two magnetic tracks must be designed in opposite directions.

In an alternative embodiment, it is provided that the secondary sensor component has a measuring direction directed in a radial direction in relation to the main axis. The radial section is formed from a magnetically conductive material when the measuring direction of the secondary sensor component is directed radially to the main axis and/or perpendicular to the primary sensor component or its magnetic area. The material of the radial section is preferably magnetic and/or magnetizable and/or ferromagnetic. In particular, the primary sensor component has at least one magnetic track. This leads to a reduction in installation space, resulting in a compact torque sensor that can be used in measuring systems with little installation space.

A further object of the invention relates to a sensor unit with at least one first and one second machine element and with the magneto-elastic sensor unit according to one of the preceding claims. The first machine element runs coaxially to the second machine element and is arranged at a radial distance from it. Typically, the machine elements are formed by a shaft guided in a housing, by a rotary bearing or by similar components that can rotate relative to one another. In particular, the arrangement relates to an electric drive train which is designed and/or suitable for driving a vehicle, preferably a hybrid or electric vehicle. For example, the electric drive train can be designed as a traction drive, e-drive or e-axle for this purpose. Alternatively, the electric drive train is designed and/or suitable for a roll stabilizer or a wind turbine. In particular, the arrangement can be used in a transmission and/or drive device of the drive train. One of the two machine elements is designed as a rotor and/or gear shaft, in particular a pinion, intermediate or output shaft. Used in particular in the transmission device, the sensor unit is and/or can be arranged in and/or on the pinion, intermediate or output shaft. In particular, the sensor unit is attached between the two machine elements in such a way that a closed sensor unit is formed, in which the primary sensor element is attached to one machine element and the secondary sensor component is attached to the other machine element. In particular, one machine element is designed as a stationary and/or housing-fixed machine element, e.g. housing or retaining rod, and the other machine element as the torque- and/or force-loaded machine element, e.g. shaft, with the primary sensor component having the torque- and/or force-loaded machine element is connected and the secondary sensor component is connected to the stationary and / or housing-fixed machine element.

• 1 eine Anordnung mit einer Sensoreinheit in einer schematischen Schnittdarstellung als ein erstes Ausführungsbeispiel der Erfindung;
• 2 die Sensoreinheit aus 1 in einem schematischen Längsschnitt;
• 3 die Sensoreinheit aus 1 in einem schematischen Querschnitt;
• 4 eine alternative Ausführung der Sensoreinheit in einem schematischen Längsschnitt als ein zweites Ausführungsbeispiel der Erfindung;
• 5 die Sensoreinheit der 4 in einer einem schematischen Querschnitt;
• 6 eine alternative Ausführung der Sensoreinheit gemäß 4 als ein drittes Ausführungsbeispiel der Erfindung;
• 7 eine alternative Ausführung der Sensoreinheit gemäß 1 als ein viertes Ausführungsbeispiel der Erfindung;
• 8 eine alternative Ausführung der Sensoreinheit gemäß 4 als ein fünftes Ausführungsbeispiel der Erfindung;
• 9 eine alternative Ausführung der Sensoreinheit gemäß 3 als ein sechstes Ausführungsbeispiel der Erfindung;
• 10 eine alternative Ausführung der Sensoreinheit gemäß 5 als ein siebtes Ausführungsbeispiel der Erfindung;
• 11 eine weitere alternative Ausführung der Sensoreinheit gemäß 3 als ein achtes Ausführungsbeispiel der Erfindung;
• 12 eine weitere alternative Ausführung der Sensoreinheit gemäß 5 als ein neuntes Ausführungsbeispiel der Erfindung;
• 13 eine weitere alternative Ausführung der Sensoreinheit gemäß 4 als ein zehntes Ausführungsbeispiel der Erfindung;
• 14 eine weitere alternative Ausführung der Sensoreinheit gemäß 4 als ein elftes Ausführungsbeispiel der Erfindung;
• 15 eine weitere alternative Ausführung der Sensoreinheit gemäß 4 als ein zwölftes Ausführungsbeispiel der Erfindung;
• 16 eine weitere alternative Ausführung der Sensoreinheit gemäß 4 als ein dreizehntes Ausführungsbeispiel der Erfindung;
• 17 eine weitere alternative Ausführung der Sensoreinheit gemäß 4 als ein vierzehntes Ausführungsbeispiel der Erfindung;
• 18 eine weitere alternative Ausführung der Sensoreinheit gemäß 4 als ein fünfzehntes Ausführungsbeispiel der Erfindung;
• 19 eine alternative Ausführung der Anordnung gemäß 1 als ein sechzehntes Ausführungsbeispiel der Erfindung;
• 20 eine Weiterbildung der Sensoreinheit gemäß 19 als ein siebzehntes Ausführungsbeispiel der Erfindung;
• 21 eine weitere alternative Ausführung der Anordnung gemäß 1 als ein achtzehntes Ausführungsbeispiel der Erfindung;
• 22 eine weitere alternative Ausführung der Anordnung gemäß 1 als ein neunzehntes Ausführungsbeispiel der Erfindung;
• 23 eine weitere alternative Ausführung der Anordnung gemäß 1 als ein zwanzigstes Ausführungsbeispiel der Erfindung.

Further features, advantages and effects of the invention result from the following description of preferred exemplary embodiments of the invention. show:

• 1 an arrangement with a sensor unit in a schematic sectional view as a first embodiment of the invention;
• 2 the sensor unit off 1 in a schematic longitudinal section;
• 3 the sensor unit off 1 in a schematic cross section;
• 4 an alternative embodiment of the sensor unit in a schematic longitudinal section as a second embodiment of the invention;
• 5 the sensor unit 4 in a a schematic cross section;
• 6 an alternative embodiment of the sensor unit according to 4 as a third embodiment of the invention;
• 7 an alternative embodiment of the sensor unit according to 1 as a fourth embodiment of the invention;
• 8th an alternative embodiment of the sensor unit according to 4 as a fifth embodiment of the invention;
• 9 an alternative embodiment of the sensor unit according to 3 as a sixth embodiment of the invention;
• 10 an alternative embodiment of the sensor unit according to 5 as a seventh embodiment of the invention;
• 11 a further alternative embodiment of the sensor unit according to FIG 3 as an eighth embodiment of the invention;
• 12 a further alternative embodiment of the sensor unit according to FIG 5 as a ninth embodiment of the invention;
• 13 a further alternative embodiment of the sensor unit according to FIG 4 as a tenth embodiment of the invention;
• 14 a further alternative embodiment of the sensor unit according to FIG 4 as an eleventh embodiment of the invention;
• 15 a further alternative embodiment of the sensor unit according to FIG 4 as a twelfth embodiment of the invention;
• 16 a further alternative embodiment of the sensor unit according to FIG 4 as a thirteenth embodiment of the invention;
• 17 a further alternative embodiment of the sensor unit according to FIG 4 as a fourteenth embodiment of the invention;
• 18 a further alternative embodiment of the sensor unit according to FIG 4 as a fifteenth embodiment of the invention;
• 19 an alternative embodiment of the arrangement according to 1 as a sixteenth embodiment of the invention;
• 20 according to a development of the sensor unit 19 as a seventeenth embodiment of the invention;
• 21 another alternative embodiment of the arrangement according to 1 as an eighteenth embodiment of the invention;
• 22 another alternative embodiment of the arrangement according to 1 as a nineteenth embodiment of the invention;
• 23 another alternative embodiment of the arrangement according to 1 as a twentieth embodiment of the invention.

1 shows an arrangement 1 in a schematic sectional view as a first embodiment of the invention. The arrangement 1 comprises a first and a second machine element 2, 3, which are arranged coaxially and/or concentrically with respect to one another with respect to a main axis H and are spaced apart from one another in a radial direction RR. In this exemplary embodiment, the first machine element 2 serves to transmit a torque and/or a force, with the second machine element 3 being hollow at least in sections in order to accommodate and/or house the first machine element 2 in sections. In operation, the first machine element 2 is rotated relative to the second machine element 3 about the main axis H, with the second machine element 3 remaining stationary. The main axis H thus forms an axis of rotation of the first machine element 2.

The arrangement 1 is suitable, for example, for arrangement in an electric drive train of a vehicle, in which case the first machine element 2 can be designed, for example, as a rotor shaft of an electric motor or as a transmission shaft of a transmission, and the second machine element 2 can be designed as a housing or a stationary hollow shaft . It is also conceivable to arrange such an arrangement 1 in a roll stabilizer or a wind turbine.

In addition, the arrangement 1 has a sensor unit 4 which is used for contactless detection of a torque and/or force acting on the first machine element 2 . This information can be used to improve the driving operation and/or to control and/or regulate and/or monitor the electric motor. The sensor unit 4 can be designed as a passive or active inverse magnetostrictive torque or force sensor.

For this purpose, the sensor unit 4 comprises a primary sensor component 5 , the primary sensor component 5 being connected to the first machine element 2 . For this purpose, the primary sensor component 5 has an inner cylinder 7 with an inner mounting surface 8, the inner cylinder 7 being connected in a torque-proof manner to an outer circumference of the first machine element 2 via the inner mounting surface 8, so that a torque and force-transmitting positioning of the primary sensor component 5 on the first machine element 2 is ensured . The primary sensor component 5 thus experiences the same deformation as the first machine element 2 when acted upon by the torque and/or the force. In particular, the inner cylinder 7 is designed as a cylindrical sleeve.

The sensor unit 4 also includes a secondary sensor component 6 , the secondary sensor component 6 being connected to the second machine element 3 . The secondary sensor component 6 has an outer cylinder 9 , the outer cylinder 9 being connected to an inner circumference of the second machine element 3 via an outer mounting surface 10 . In particular, the outer cylinder 9 is designed as a further cylindrical sleeve, with the inner cylinder 7 and the outer cylinder 9 being arranged coaxially and/or concentrically with respect to the main axis H. For example, the inner and/or the outer cylinder 7, 9 can be attached by pressing, gluing, Soldering or welding with the respective machine element 2, 3 can be connected.

The primary sensor component 5 has a magnetic area M which causes a magnetic field change in a magnetic field when the first machine element 2 is loaded with the force and/or the torque due to the inverse magnetostrictive effect occurring in the material. For this purpose, the primary sensor component 5 in particular has a material or a surface or coating which exhibits the inverse magnetostrictive effect when a mechanical force component is impressed. For example, the primary sensor component 5 itself can be formed from a magnetizable and/or magnetized material. A magnetized sleeve, which is arranged coaxially to the first machine element 2 , is particularly preferably used as the primary sensor component 5 . Alternatively, the primary sensor component 5 can be provided with a magnetizable and/or magnetized coating. For example, the primary sensor component 5 can have a circumferentially closed magnetic field that changes as a result of the torque or force being applied to the first machine element 2 .

The secondary sensor component 6 is designed to detect the change in the magnetic field of the primary sensor component 5 occurring under the action of the force and/or the torque. Designed as a passive inverse magnetostrictive torque or force sensor, the magnetic field can be present in the magnetic region M of the primary sensor component 5 and/or generated by it, with the secondary sensor component 6 having one or more magnetic field sensors which detect the magnetic field M without contact. The secondary sensor sensor component 6 has a measuring direction which is directed horizontally, in particular in the axial direction R, and/or vertically, in particular in the radial direction R, to the primary sensor component 7 . For this purpose, the secondary sensor component 6 comprises a plurality of sensor elements 12 which are arranged on a circuit board 13 or are embedded in it. Designed as an active inverse-magnetostrictive torque or force sensor, the secondary sensor component 6 can have at least one primary coil and at least one secondary coil as the sensor elements 12, with the magnetic field being generated via the at least one primary coil and being detected via the at least one secondary coil.

The sensor unit 4 has a first and a second radial section 15a, b, which are arranged on the primary sensor component 5 or on an outer circumference of the inner cylinder 7 and are directed outwards in the radial direction RR. The primary sensor component 5 and the secondary sensor component 6 are spaced apart from one another in the radial direction RR and are positioned relative to one another in the radial direction RR and in the axial direction AR by the two radial sections 15a, b. The two radial sections 15a, b can each be formed by a flanged wheel which is connected to the inner cylinder 7 in a positive, non-positive or material connection. Alternatively, however, it is also conceivable that the two radial sections 15a, b and the inner sleeve 7 are made from a common material section and are therefore connected to one another in one piece. In particular, a measuring space 14 is defined between the two sensor components 5, 6, which is delimited in the axial direction AR by the radial sections 15a, b and in the radial direction RR by the inner and outer cylinders 7, 9, respectively.

In this embodiment, the secondary sensor component 6 is arranged in the axial direction AR between the two radial sections 15a, b and is thus held captive in the axial direction. As a result of this construction, the primary sensor component 5 and the secondary sensor component 6 are held together to form a unit even when they are removed. In the installed state, the secondary sensor component 6 is arranged at an axial distance from the two radial sections 15a, b and in the radial direction RR at a radial distance from the primary sensor component 7 . In this way, the primary sensor component 5 can be held approximately in position radially and its surface cannot strike the secondary sensor component 6 .

The two radial sections 15a, b are each arranged in an axial end area of the inner cylinder 7, where they also serve to reinforce a torque and/or force transmission area. In particular, the torque and/or force transmission area is defined as an area of the primary sensor component 5 into which the torque and/or force is introduced or discharged when the first machine element 2 is loaded.

The two radial sections 15a, b are preferably formed from a non-magnetically or poorly magnetically conductive material when the measuring direction of the secondary sensor component 6 is directed in the axial direction RA or horizontally to the primary sensor component 5. For example, the two radial sections 15a, b can be made of plastic. Alternatively, the two radial sections 15a, b are formed from a magnetically conductive material if the measuring direction of the secondary sensor component 6 is directed in the radial direction RR or perpendicular to the primary sensor component 5.

The two radial sections 15a, b are arranged spaced apart from the second machine element 3 in the radial direction RR, the gap formed thereby for the passage an electrical line 16, for example a cable for the secondary sensor component 6 can be used.

the 2 and 3 each show the sensor unit 4 in a removed state, with FIG 4 a cross-section AA, as in 2 indicated, the sensor unit 4 is shown. Once again 3 As can be seen, the secondary sensor component 6, in particular the outer cylinder 9, has a plurality of recesses 17 distributed around the main axis H in the direction of rotation, which is used to accommodate a circuit board 13 with the sensor elements 12 arranged thereon. Overall, the secondary sensor component 6 uses four of the recesses 17, which are each offset by 90 degrees. The recesses 17 can each be formed by a groove, pocket or impression, one of the circuit boards 13 being accommodated in each recess 17 . In particular, the sensor elements 12 are offset in the radial direction RR with respect to the inner diameter of the outer cylinder 9, as a result of which the sensor elements 12 are protected.

the 4 and 5 show the sensor unit 4 in a schematic longitudinal and cross-sectional view as a second embodiment of the invention. The sensor unit 4 is functionally identical to the sensor unit 4 already described above, which is why a further description of the function is dispensed with and only the structural differences are discussed. The sensor unit 4 is suitable for an arrangement 1 in which the second machine element 3, cf. 1 , Is acted upon by the torque and/or the force and the first machine element 2 remains stationary. During operation, the second machine element 3 is thus rotated about the main axis H relative to the first machine element 2 . For example, the second machine element 3 is designed as a hollow shaft and the first machine element 2 is designed as a holding rod guided coaxially in the hollow shaft.

The primary sensor component 5 is and/or can be arranged on the second machine element 3 and the secondary sensor component 6 on the first machine component 2 . For this purpose, the primary sensor component 5 comprises the outer cylinder 9 and the secondary sensor component 6 the inner cylinder 7, with the inner cylinder 7 and the outer cylinder 9 being designed accordingly for detecting the torque and/or the force on the basis of the magnetostrictive effect, as described above.

In this embodiment 15a, b, the two radial sections 15a, b are arranged on an inner circumference of the outer cylinder 9 and are therefore directed inwards in the radial direction RR. The secondary sensor component 6 or the inner cylinder 7 is thus arranged in the axial direction AR between the two radial sections 15a, b with the axial spacing and in the radial direction RR with the radial spacing from the primary sensor component 5 or the outer sleeve 9 .

the 6 shows the arrangement 1 with the sensor unit 4 according to FIG 4 and 5 as a third embodiment of the invention. In this embodiment, the sensor unit 4 additionally has a first and a second sealing device 18a, b, which serves to seal the measuring space 14 formed between the primary sensor component 5 and the secondary sensor component 6. The first sealing device 18a is arranged on a free radial end of the first radial section 15a and the second sealing device 18b on a free radial end of the second radial section 15b. For this purpose, the two radial sections 15a, b each have a circumferential seal receptacle 19a, b, for example an annular groove, in which the associated sealing device 18a, b is accommodated. The two sealing devices 18a, b are each designed as a circumferential sealing lip, which in the installed state of the sensor unit 4 bears tightly against the outer circumference of the first machine element 2. The measuring chamber 14 is thus delimited in the axial direction AR by the two radial sections 15a, b and preferably sealed in a fluid-tight manner by the sealing devices 15a, b.

Alternatively, the sensor unit 1 until 3 also have the sealing devices 18a, b, which bear against the inner circumference of the second machine element 3 in a sealing manner in order to seal off the measuring chamber 14.

the 7 and 8th each show a modified form of the primary sensor component 5 as further exemplary embodiments of the invention. The sensor unit 4 of 7 same as the one in the 1 until 3 shown construction, wherein in this embodiment, the primary sensor component 5 designed as an inner cylinder 7 has a free space 20 for magnetic decoupling of the primary sensor component 5 from the first machine element 2 . The sensor unit 4 of 8th same as the one in the 4 and 5 shown construction, wherein in this embodiment, the primary sensor component 5 designed as an outer cylinder 9 has a free space 20 for magnetic decoupling of the primary sensor component 5 from the second machine element 3 . An air gap, in particular an annular gap running around the main axis H, can be formed between the primary sensor component 5 and the respective machine element 2 , 3 through the free space 20 . Optionally, the free space 20 can be made of a non-magnetizable or non-magnetic material be filled in order to realize the magnetic decoupling. For example, the free space 20 can be formed by a radial edging of the inner or outer cylinder 7, 9.

the 9 and 10 12 each show a further modified form of the sensor unit 4, with the primary sensor component 5 being constructed in multiple layers in this embodiment. The sensor unit 4 of 9 same as the one in the 1 until 3 shown construction, wherein in this embodiment the primary sensor component 5 has a non-magnetizable or difficult-to-magnetize intermediate layer 21 for magnetic decoupling of the inner cylinder 7 from the first machine element 2 . The sensor unit 4 of 10 same as the one in the 4 and 5 shown construction, wherein in this embodiment, the primary sensor component 5 has a non-magnetizable or difficult-to-magnetize intermediate layer 21 for magnetic decoupling of the outer cylinder 9 from the second machine element 3. The intermediate layer 21 can be designed as a separate sleeve or a coating, which is arranged on the inner mounting surface 8 of the inner cylinder 7 or on the outer mounting surface 10 of the outer cylinder 9 . Alternatively, however, the intermediate layer 21 can also be arranged and/or fastened on the corresponding machine element 2, 3 itself or form part of it.

the 11 and 12 each show a further modified form of the sensor unit 4 as further exemplary embodiments of the invention. The sensor unit 4 of 11 same as the one in the 1 until 3 shown construction, in this embodiment the secondary sensor component 6 has a plurality of functional layers 22 offset by 90 degrees in the direction of rotation, which are integrated into the inner circumference of the outer cylinder 9 as a secondary sensor system. The sensor unit 4 of 12 same as the one in the 4 and 5 shown construction, wherein in this embodiment, the secondary sensor component 6 has a plurality of functional layers 22 offset by 90 degrees in the direction of rotation, which are integrated into the outer circumference of the inner cylinder 7 as a secondary sensor system.

the 13 until 18 each show further modified forms of the sensor unit 4 as further exemplary embodiments of the invention, the sensor unit 4 being of the type shown in FIGS 4 and 5 construction shown.

In execution after 13 until 17 the secondary sensor component 6 has a carrier element 23, the inner cylinder 7 being connected to the first machine element 2 in a torque-proof manner via the carrier element 23. In the embodiments with the carrier element 23, the inner cylinder 7 is connected to the carrier element 23 in a rotationally fixed manner, with the carrier element 23 in turn being connected to the first machine element 2 in a positive and/or non-positive manner. The carrier element 23 is preferably made of plastic or a non-magnetizable or poorly magnetizable, in particular non-ferromagnetic, metal. Depending on the design of the first machine element 2, the carrier element 23 can be tubular or sleeve-shaped, partially hollow or have a full cross-section, as will be explained in more detail in the following figures.

Alternatively, the secondary sensor component 6 or the inner cylinder 7 can be formed by the carrier element 23, with the carrier element 23 being manufactured from a material section or in one piece, as is shown in 18 is shown.

According to the statements of 13 and 14 the carrier element 23 is tubular and is pressed onto the first machine element 2, for example, during assembly for a non-rotatable connection. In the tubular configuration, the carrier element 23 and thus the entire sensor unit 4 can be positioned at any position along the first machine element 2 .

If the carrier element 23 as a full cross-section, as in the 15 , 16 and 18 shown, or partially hollow, as in 17 shown, formed, a connection interface 24 for receiving the first machine element 2 in a rotationally fixed manner is formed or formed on the carrier element 23 . The secondary sensor component 6 is secured against unwanted rotation via the connection interface 24 . The connection interface 24 can, for example, be in the form of a hexagon socket, with the first machine element 2 having an external hexagon at the end which is designed to complement it. Consequently, the carrier element 23 and the machine element 2 are connected to one another in a torque-proof manner via a plug-in connection.

The sensor unit 4 has a first and a second bearing device 25a, b, the first radial section 15a being rotatably mounted radially on the carrier element 23 via the first bearing device 25a and the second radial section 15b via the second bearing device 25b. According to the 13 and 15 until 18 the two bearing devices 15a, b are each designed as plain bearings, for example a plain bearing sleeve, so that the primary sensor component 5 is slidably mounted relative to the carrier element 23.

According to 14 on the other hand, the two bearing devices 25a, b are each designed as roller bearings, for example needle bearings, with the two radial sections 15a, b each having a plurality of roller bearings body are mounted on the carrier element 23. The rolling elements of the two bearing devices 25a, b after 14 are secured axially by axial stops on the carrier element 23. For this purpose, a radial shoulder 26 is formed on the outer circumference of the carrier element 23 on one side of the carrier element 23 , whereas a locking ring 27 is provided on the opposite axial side, which is received radially in a groove 28 on the carrier element 23 . In addition, an intermediate ring 29 is provided between the retaining ring 27 and the second radial section 15b, but this could be dispensed with depending on the design of the retaining ring 27 .

19 shows a further alternative embodiment of the sensor unit 4. In this embodiment, the primary sensor component 5 is designed as a sleeve, with the magnetic region M being formed by two magnetic tracks 11a, b, which form an opposing magnetic field. The secondary sensor component 6 or the sensor elements 12 are arranged horizontally to the primary sensor component 8 .

In the embodiment according to 19 the primary sensor component 5 has two supporting webs 30a, b and a stiffening ring 31. In this embodiment, the webs 30a, b each have the mounting inner surface 8 at their free ends, via which the primary sensor component 5 is attached to the first machine element 2. The stiffening ring 31 runs parallel to the main axis H between the two webs 30a, b and serves to stiffen the primary sensor component 5.

In the embodiment according to 19 the radial sections 15a, b are arranged laterally on the secondary sensor component 6 or the outer cylinder 9, with no direct connection of the two radial sections 15a, b to the first machine element 2. In addition, the second radial section 15b has an internal recess 32 at the end. The second web 30b of the primary sensor component 4 engages in this recess 32 so that it is held in position radially and axially relative to the secondary sensor component 6 . At the same time, a gap remains between the radial sections 15a, b and the webs 30a, b, which allows rotation between the primary and secondary sensor components 5, 6.

20 1 shows a detailed view of a modified embodiment of the secondary sensor component 6 in radial section 19 . In this case, a sealing device 18a, b is attached to the free ends of the radial sections 15a, b, as already mentioned in the context of FIG 6 was described.

21 shows a further alternative embodiment of the sensor unit 4 in a radial section. This embodiment corresponds to the basic features of the embodiment according to FIG 19 , but has the difference that the primary sensor component 5 has only a single magnetic track 11a and the sensor elements 12 of the secondary sensor component 6 are arranged perpendicular to the primary sensor component 5. The course of the magnetic field to be recorded is as in 21 shown, symbolized by a drawn field line, and oriented perpendicular to the primary sensor component 5 .

the 22 and 23 each show a sectional view of a further alternative embodiment of the sensor unit 4, which initially corresponds to the embodiment 19 equals. However, in the versions shown, it is built flat, so that the stiffening ring 31 and the webs 30a, b can be dispensed with and with the versions of 1 until 12 is comparable.

The primary sensor component 5 of 22 is designed as a flat sleeve made of magnetizable or magnetic material with an inverse magnetostrictive effect, which is placed on the first machine element 2, so that the space required remains small. For this purpose, the inner cylinder 7 has the inner mounting surfaces 8 on its radially inner side, which are attached directly to the first machine element 2 . The primary sensor component 5 can, for example, be glued, soldered or welded to the first machine element 2 as a strip.

The secondary sensor component 6 is composed of an L-shaped ring viewed in longitudinal section, which combines the outer cylinder 9 and the first radial section 15a, and the second radial section 15b. The recess 32 in which the primary sensor component 5 engages is worked into the second radial section 15b.

In accordance with the design 23 is located between the first machine element 2 and the mounting surface 8, the magnetically decoupling intermediate layer 21, which consists of non-magnetizable material or can be formed as an air gap.

Reference List

1

arrangement

2

first machine element

3

second machine element

4

sensor unit

5

primary sensor component

6

secondary sensor component

7

inner cylinder

8th

mounting inner surface

9

outer cylinder

10

mounting surface

11a, b

magnetic tracks

12

sensor element

13

circuit board

14

measuring room

15a, b

radial sections

16

Management

17

recesses

18a, b

sealing devices

19a, b

seal mounts

20

free space

21

intermediate layer

22

functional layer

23

carrier element

24

connection interface

25a, b

storage facilities

26

Unit volume

27

locking ring

28

groove

29

intermediate ring

30a, b

webs

31

stiffening ring

32

recesses

H

main axis

M

magnet area

AR

axial direction

RR

radial direction

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102017200528 A1 [0003]

Claims (10)

Magnetoelastic sensor unit (4) for detecting a force and/or torque acting on a component (2, 3), with a primary sensor component (5), the primary sensor component (5) having a magnetic region (M) which, when the component ( 2, 4) causes a magnetic field change of a magnetic field with the force and/or the torque, with a secondary sensor component (6) for detecting the magnetic field change of the magnetic field occurring under the action of the force and/or the torque on the component (2, 4), wherein the primary sensor component (5) and the secondary sensor component (6) are arranged coaxially to one another in relation to a main axis (H) and can be rotated relative to one another in a direction of rotation, characterized by at least one radially extending radial section (15a), the radial section (15a) being fixed is connected to one of the two sensor components (5, 6), wherein the primary sensor component (5) and the secondary sensor component (6) through the radia lportion (15a) are kept spaced from each other in a radial direction (RR) and are secured relative to each other in an axial direction (AR). Magnetoelastic sensor unit (4) after claim 1 , characterized by at least one further radial section (15b), the at least two radial sections (15a, b) being spaced apart from one another in the axial direction (AR) on one sensor component (5, 6) and the other sensor component (5, 6) is arranged in the axial direction (AR) between the at least two radial sections (5, 6) with an axial spacing, the two sensor components (5, 6) being held together by the at least two radial sections (15a, b) to form a common structural unit. Magnetoelastic sensor unit (4) after claim 1 or 2 , characterized in that one sensor component (5, 6) has an outer cylinder (9) and in that the other sensor component (5, 6) has an inner cylinder (7) arranged at a radial distance in the outer cylinder (9), the at least a radial section (15a, b) for axially securing the inner cylinder (7) is arranged on an inner circumference of the outer cylinder (9), or the at least one radial section (15a, b) for axially securing the outer cylinder (9) on an outer circumference of the inner cylinder ( 7) is arranged. Magnetoelastic sensor unit (4) after claim 3 , characterized in that the at least one radial section (15a, b) is arranged on an axial end area of the inner cylinder (7) or the outer cylinder (9) in order to increase a torque and/or force transmission area. Magnetoelastic sensor unit (4) after claim 3 or 4 , characterized in that the inner cylinder (7) has an inner mounting surface (8) for mounting on an inner component (2) and/or that the outer cylinder (9) has an outer mounting surface (10) for mounting on an outer component (3). Magnetoelastic sensor unit (4) according to one of the preceding claims, characterized by at least one sealing device (18a, b) for sealing a measuring space (14) formed between the primary sensor component (5) and the secondary sensor component (6), the sealing device (18a, b) is arranged at a free radial end of the radial section (15a, b). Magnetoelastic sensor unit (4) according to one of the preceding claims, characterized by at least one bearing device (25a, b) for the rotatable bearing of the primary sensor component (5) relative to the secondary sensor component (6), the bearing device (25a, b) on a free radial End of the radial section (15a, b) is arranged. Magnetoelastic sensor unit (4) according to one of the preceding claims, characterized in that the secondary sensor component (6) has a measuring direction directed in the axial direction (AR), the at least one radial section (15a, b) consisting of a non-magnetically conductive or a poorly -Magnetically conductive material is formed. Magnetoelastic sensor unit (4) according to one of Claims 1 until 8th , characterized in that the secondary sensor component (6) has a measuring direction directed in the radial direction (RR), the at least one radial section (15a, b) being formed from a magnetically conductive material. Arrangement (1) with at least one first and one second machine element (2, 3), wherein the first machine element (2) runs coaxially to the second machine element (3) and is spaced radially, with a magnetoelastic sensor unit (4) according to one of the preceding claims , characterized in that the primary sensor component (5) on which a machine element (2, 3) is arranged and that the secun där sensor component (6) on the other machine element (2, 3) is arranged.

Images