Rotary sensor and steering system for a motor vehicle

Abstract

The invention relates to a rotary sensor for a steering system of a motor vehicle, comprising a ring gear mounted in a housing in a rotatable manner about an axis, and an inner toothing and a coupling element designed for connection to a steering shaft, which can be rotated about its longitudinal axis, the housing having an axial end wall, an axial inner wall and a coaxially extending circumferential wall, the ring gear being arranged axially between the end wall and the inner wall and being circumferentially enclosed with respect to the axis by the circumferential wall, at least one measuring wheel having a magnetic element being mounted in the housing in a rotatable manner and engaging with its outer toothing in the inner toothing of the ring gear, a measuring element cooperating with the magnetic element of the measuring wheel being mounted in the housing. In order to improve the operating safety and to achieve a more compact design, it is proposed that the end wall and the inner wall are formed continuously closed in the interior enclosed by the inner toothing.

Description

Technical Field

[0001] This invention relates to a rotary sensor for a steering system of a motor vehicle, comprising: a ring gear rotatably mounted in a housing; internal teeth and a connecting element designed for connection to a steering shaft rotatable about its longitudinal axis; wherein the housing has an axial end wall, an axial inner wall, and a coaxially extending circumferential wall; wherein the ring gear is axially arranged between the end wall and the inner wall and circumferentially enclosed about the axis by the circumferential wall; and wherein at least one measuring wheel having a magnetic element is rotatably mounted in the housing and engages with the internal teeth of the ring gear by means of the external teeth of the measuring wheel; and wherein a measuring element cooperating with the magnetic element of the measuring wheel is mounted in the housing. A steering system for a motor vehicle having such a rotary sensor is also the subject of this invention. Background Technology

[0002] In steer-by-wire systems of motor vehicles, an electrically operated rotary sensor detects the rotation of the steering column's steering shaft, such as the steering master shaft, caused by manual actuation of the steering handle. Based on the measured angle, an electrical control signal is generated to control the electric steering drive, which causes the steering wheels to produce a corresponding steering angle. This rotary sensor can also be used to measure the rotation of another steering shaft, which is directly or indirectly involved in steering.

[0003] For example, a general-purpose rotary sensor is described in JP 2009262848 A. This rotary sensor includes a ring gear coupled to a steering shaft, the ring gear having internal teeth extending about an axis. Two measuring wheels, having different numbers of teeth, are arranged inside the ring gear and engage with it in a toothed manner. Each of the measuring wheels has a commonly rotating magnetic element, the angle-dependent magnetic field of which is detected by a designated measuring element fixed relative to a housing. Based on the measuring magnetic fields of the two measuring wheels, the angular position of the ring gear, and therefore the angular position of the steering shaft, can be definitively determined over several rotations.

[0004] In known rotary sensors, a ring gear, measuring wheel, and measuring elements are housed together in a housing. This housing includes an end wall axially positioned in front of the ring gear, an inner wall axially positioned on the other side of the ring gear, and a circumferential wall or outer shell wall positioned between the end wall and the inner wall and extending around the ring gear, thereby defining the internal space of the housing. A steering shaft is axially guided through a central support opening in the inner and end walls and is rotatably mounted within the central support opening. Inside the housing, the ring gear is rotatably fixed to the steering shaft by means of a hub. This means that all functional elements of the sensor are integrated within the housing. However, a disadvantage is that the rotatable steering shaft extends through the housing, and the measuring wheel, along with the sensor electronics, is housed within the housing. The support for the steering shaft may allow potentially harmful external influences to enter and impair functionality. Furthermore, the functional elements must be arranged in a protected position relative to the internally rotating ring gear. This results in a relatively large installation space requirement, which is also considered a drawback.

[0005] In the prior art, versions with measuring wheels are also known.

[0006] In view of the above problems, the object of the present invention is to achieve improved operational safety and a more compact design. Summary of the Invention

[0007] According to the invention, this objective is achieved by a rotary sensor having a principal aspect of this aspect and a steering system having a principal aspect of this aspect. Advantageous improvements are presented from the appended aspects of the invention.

[0008] In a rotary sensor for a steering system of a motor vehicle, the rotary sensor includes: a ring gear mounted in a housing in a manner rotatable about an axis; and an internal gear and a connecting element designed for connection to a steering shaft rotatable about its longitudinal axis, wherein the housing has an axial end wall, an axial inner wall, and a coaxially extending circumferential wall, wherein the ring gear is axially arranged between the end wall and the inner wall and is circumferentially enclosed about the axis by the circumferential wall, and wherein at least one measuring wheel having a magnetic element is rotatably mounted in the housing and engages in the internal gear of the ring gear by means of the external teeth of the measuring wheel, and wherein a measuring element cooperating with the magnetic element of the measuring wheel is mounted in the housing, wherein, according to the invention, the end wall and the inner wall are formed as a continuous closed space within the interior enclosed by the internal gear.

[0009] Preferably, at least two measuring wheels are rotatably mounted in the housing, each measuring wheel having a magnetic element and engaging with the internal teeth of a ring gear via the external teeth of the measuring wheel. A measuring element that mates with the magnetic element of the measuring wheel is mounted in the housing. The two measuring wheels have different numbers of teeth, thus enabling the implementation of a vernier measurement principle. Regarding the measuring wheels mentioned below, this should include both versions with one measuring wheel and versions with two or more measuring wheels.

[0010] In the following text, the steering shaft is generally understood as a rotatable shaft or rotatable driven shaft of a motor vehicle steering system, the rotation of which can be detected by a rotary sensor. The steering shaft may include, for example, a manually rotatable steering spindle of a steering column, preferably a steer-by-wire steering column, but is not limited thereto.

[0011] The internal gear is formed to extend coaxially around an axis on the inner circumference of the ring gear. At least two measuring wheels—each having external gears with different numbers of teeth—are rotatably mounted inside the ring gear and engage in toothed gearing within the internal gear. The interior enclosed by the ring gear can also be synonymously referred to as the passageway of the internal gear or simply the passageway. It is entirely conceivable and possible that this passageway is axially closed by a completely or partially continuous wall. In this case, the interior of the ring gear can be can-shaped, axially open towards the inner wall.

[0012] According to the invention, the end wall of the housing is arranged axially outward relative to the ring gear and is continuously closed. Therefore, this end wall forms the outer shell wall, which, unlike prior art with through-wall support holes for the steering shaft, lacks a continuous through-hole. The end wall connects to the circumferential wall of the housing, which may be tubular, preferably hollow cylindrical. On the opposite axial side, the housing has an inner wall. This means that the ring gear is arranged axially between the inner wall and the end wall. Therefore, the interior of the housing—where the ring gear is rotatably mounted—is axially defined by the end wall and radially defined by the circumferential wall.

[0013] The ring gear has a ring shape, wherein the internal teeth of the ring gear enclose an axially open inner cross section on both sides of the circumference, and are thus radially outwardly bounded about the axis. The interior extends transversely to the axis on the inner cross section of the ring gear enclosed by the internal teeth, and extends axially, i.e. in the axial direction, between opposing, continuously closed axially portioned surfaces of the inner wall and the end wall according to the invention.

[0014] Therefore, the internal axial width is greater than or equal to the axial width of the internal teeth.

[0015] Therefore, the interior between the front wall and the inner wall is essentially cylindrical. The cross-section of the empty, essentially disc-shaped passage inside can be measured between the radially inwardly projecting tooth tips of the internal teeth.

[0016] According to the present invention, the end walls and inner walls axially and continuously cover the interior of the ring gear. In this case, the end walls and inner walls have no openings or apertures in the passage cross-section of the ring gear, i.e., in the region of the internal teeth. In particular, there is no central, axially continuous support opening for the steering shaft. In the prior art mentioned above, the support opening extends through the inner wall and end walls.

[0017] The advantage of the device according to the invention is that the entire interior of the ring gear is available for the arrangement of the functional elements of the sensor device, such as the arrangement and storage of the measuring wheels, the arrangement of the measuring elements that cooperate with the measuring wheels, and the arrangement and design of the circuitry that cooperates with the measuring elements. This results in greater design freedom, as well as the possibility of reducing installation space and optimizing functionality.

[0018] Another advantage is that the entire measurement arrangement, including the measuring wheel, measuring elements, and circuitry, can be better housed inside the ring gear to prevent potentially harmful external influences, such as preventing impurities from entering through the support openings of the steering shaft.

[0019] Since the ring gear inside the housing is not connected to the hub of the steering shaft, there are no rotating parts inside the housing enclosed by the ring gear, which eliminates the need for protective measures as in the prior art and thus allows for a more compact design.

[0020] Another advantage is that the rotary sensor can be optimally mounted on the axial end of the steering shaft. For this, it is only necessary to allow torque to be transmitted from the axial end of the steering shaft to the ring gear.

[0021] The following are examples of advantageous solutions. These examples particularly enable the advantageous integration of rotary sensors into a steering column with wire steering, wherein the steering shaft comprises a manually rotatable steering spindle that is not mechanically connected to the steerable wheels. In this case, a rotary sensor according to the invention for detecting manual steering commands can preferably be mounted at the front end of the steering spindle.

[0022] Preferably, the ring gear may have an axial passage defined circumferentially by the internal teeth. The ring gear may be an open ring gear of an annular shape. The cross-section of the empty passage of the ring gear may preferably be defined substantially by the internal teeth, i.e., defined only by the tooth surface. Since the steering shaft does not pass through the internal space between the front wall and the inner wall, the ring gear in the internal space has no hub connected to the steering shaft, and the internal space advantageously has no rotating parts.

[0023] Advantageously, the ring gear is axially sealed against the end wall and / or inner wall. This seal can preferably be achieved by an annular sealing element that extends outward in a ring shape coaxial about an axis, surrounding the interior, and is arranged between the axially opposite surfaces of the ring gear and the inner wall and / or end wall. Such a sealing element can include, for example, an axial seal, such as a sealing ring having a predetermined radius for rotation about an axis. Preferably, the sealing element can be designed to allow low-friction rotation of the ring gear relative to the housing.

[0024] The ring gear can be mounted on the end wall and / or inner wall in an axially supported arrangement. As achieved in the prior art through a central continuous support hole in the end wall and inner wall, such an axially supported arrangement allows for rotatable support without a central continuous radial support element. Conversely, the axially supported arrangement does not have a central support hole. The end wall and / or inner wall are closed in the axial region. The axially supported arrangement can be formed in the axial surfaces opposite to the ring gear and in the end wall or inner wall, or on the axial surfaces opposite to the ring gear and in the end wall or inner wall. For example, an axially projecting coaxial annular protrusion can be arranged on the axial surface, engaging in a corresponding annular groove in the opposing axial surface. The annular protrusion and / or annular groove can be formed only on one or both axial sides of the ring gear. Alternatively, a bolt-shaped axially projecting central support protrusion can be provided, engaging in a corresponding concave injection portion of the ring gear; however, the ring gear does not have a continuous axial opening through the end wall or inner wall. The advantage of this axial support arrangement is that the interior of the ring gear can be covered by the end wall and the inner wall in a continuous closed manner, and in particular, there is no continuous support hole as presented in the prior art.

[0025] Axial support can be achieved by rotatably inserting the inner wall into the support recess of the ring gear. In this embodiment, the inner wall itself can be formed as an axial cover, which fits into the axial support recess of the ring gear, which is formed to extend around the interior. In other words, the ring gear is mounted on the inner wall itself and is rotatable. In this case, the support surfaces can be arranged on the outwardly extending circumferential surface and the axial surface located in the edge region. The advantage is a simple design with fewer parts and a completely secure internal enclosure.

[0026] The inner wall can be connected to the end wall via at least one connecting device axially passing through the interior. The opposing inner portions of the end wall and the inner wall—which axially define the interior space on both sides—can be connected, for example, by one or more connecting elements. For instance, the end wall may have one or more axial protrusions, to which the inner wall is axially supported and secured. Preferably, the connecting device can be configured to position the inner wall relative to the end wall at a defined axial distance, making a rotational support axially arranged between ring gears possible. An advantageous compact design with relatively few components becomes possible.

[0027] An advantageous embodiment may be configured such that a coaxial, axially open annular gap is formed around the outer side of the inner wall. The annular gap preferably has a circular axial passage cross-section and may be circumferentially arranged between the outer circumference of the inner wall and the hollow cylindrical inner circumference of the housing. The inner circumference may be formed on the radially inner side of the housing or on the circumferential wall of the housing, and the inner circumference restricts the receiving space of the housing. In the receiving space, the ring gears are arranged, for example, axially adjacent, such that a connecting element for connecting the ring gears to a steering shaft—which can rotate about its longitudinal axis—can be arranged in the annular gap. The connecting element may be formed in the region of the annular opening cross-section of the annular gap from the axially inner side of the ring gears. One or more connecting elements may be provided, extending axially from the ring gears through the annular gap. On the drive side, i.e., on the axial side of the inner wall opposite to the ring gears, the rotationally driven steering shaft can be rotatably connected to the connecting element. Therefore, the rotational motion to be measured can be advantageously coupled to the ring gears.

[0028] In the design mentioned above, the connecting element can be configured to extend axially through the annular gap. The connecting element is designed to couple torque from a steering shaft arranged on the axial side of the inner wall away from the ring gear. This steering shaft can, for example, have an axially oriented shaft end abutting against the inner wall, such as the front end of the steering spindle of a steer-by-wire column. For example, an advantageous embodiment can be achieved by connecting a ring gear, such as an inner ring gear—with the drive wheel connected to the steering shaft or steering spindle engaging in gear-like contact with the inner ring gear—through the annular gap. Preferably, the connecting element is integrally or in one piece with the ring gear. Alternatively, the connecting element can also allow torque-locked engagement between the steering shaft and the ring gear, for example, by means of a pin or pawl connection known per se. The connecting element can pass through the annular gap at least indirectly in the axial direction.

[0029] Advantageously, the shell is can-shaped. The shell can have a basic shape of can, cup, or dome, formed by a closed end wall according to the invention and an associated circumferential wall of a generally tubular cross-sectional shape, preferably hollow cylindrical. The interior of the preferred cylindrical shell can be demarcated on the drive side axially away from the end wall by an inner wall designed according to the invention. In this case, the inner wall can be installed within the shell or at least adjacent to the shell for a compact, protected design.

[0030] It can be configured that the end wall and the circumferential wall are formed as a single piece. A single-piece design can be achieved, for example, through metal die casting, plastic injection molding, or metal sheet molding, and can enable efficient production.

[0031] The housing may have fasteners. These fasteners are used to secure the vehicle's steering system, for example, for attachment to the steering column. Preferably, these fasteners are arranged externally on the housing as mounting flanges, which may have protrusions on the end wall or circumferential wall with flange holes, etc. The fasteners can be formed as a single piece with the housing, for example, during die casting or injection molding. This allows for efficient production and easy assembly, for example, mounting to the steering column via end flanges.

[0032] Preferably, the measuring wheel can be mounted on the end wall. On the inner side facing the ring gear, a support element constructed or designed to support the measuring wheel, such as a support journal protruding into the interior of the ring gear, can be attached to the end wall, with the measuring wheel rotatably mounted on the support element. This allows for easy mounting of the measuring wheel by axially assembling it onto the support journal. A toothed engagement with the internal teeth of the ring gear can be achieved. For efficient production, it is advantageous that the support element, such as the axial support journal, is formed as a single piece on the end wall, for example, during die casting or injection molding.

[0033] Advantageous improvements can be achieved because the inner wall has a circuit board. The circuit board generally refers to an electrical circuit board, preferably a single-layer or multi-layer printed circuit board, which serves as a carrier for components of electronic circuitry and is located on an insulating board on which electrical traces for interconnecting components are arranged. These components may in particular include measuring elements or sensor elements for measuring angle-dependent magnetic fields mounted on a measuring wheel. These components can preferably be arranged on the inner side of the circuit board facing the interior of the ring gear, where they are protected within the ring gear, which is enclosed according to the invention. The advantage is that, in addition to functioning as a mechanical carrier and electrical connector for sensor circuitry, the printed circuit board can perform all the functions of the inner wall according to the invention, enclosing the interior and axially supporting and / or supporting the ring gear. Therefore, manufacturing and assembly costs can be reduced.

[0034] The circuit board can extend flatly perpendicular to the axis and is circular, i.e., disk-shaped.

[0035] The present invention includes a steering system for a motor vehicle, the steering system including a steering shaft rotatable about its longitudinal axis, the steering shaft being operatively connected to a rotary sensor for detecting rotation, wherein, according to the invention, the rotary sensor is designed with features according to one or more of the above embodiments.

[0036] Specifically, the steering shaft can be the steering spindle of a steerable column, and a rotary sensor is coupled to the front end region of the steering spindle. This allows the rotary sensor to be advantageously integrated into a steerable column, in which the steering shaft includes a manually rotatable steering spindle that is not mechanically connected to the steerable wheels at its front end, which is away from the driver's position in terms of the direction of travel. Alternatively, preferably at the front end of the steering spindle, a rotary sensor according to the invention for detecting manual steering commands can be mounted. Attached Figure Description

[0037] Advantageous embodiments of the invention will now be described in more detail with reference to the accompanying drawings. Specifically:

[0038] Figure 1 A schematic diagram of a steer-by-wire system according to the present invention is shown.

[0039] Figure 2 It shows that according to Figure 1 A schematic 3D view of a rotary sensor for the steering column.

[0040] Figure 3 It shows that according to Figure 2 Another view of the rotating sensor.

[0041] Figure 4 It is based on Figure 3 A partially open view of the rotating sensor.

[0042] Figure 5 It is through according to Figures 2 to 4 The longitudinal section of the rotary sensor. Detailed Implementation

[0043] In the various figures, the same parts are always given the same reference numerals, and therefore are usually referred to or mentioned only once in their respective cases.

[0044] Figure 1A steer-by-wire system 1 is schematically shown, comprising a steering column 2. The steering column 2 has a support unit 21, which can be mounted on a vehicle body (not shown). The steering spindle 22 of the steering column 2 is mounted in a housing unit 24 in a manner rotatable about its longitudinal axis L. A steering wheel 23 is rotatably fixed to the steering spindle 22 at the rear of the steering spindle, at the driver's side end, for inputting manual steering commands.

[0045] Steering spindle 22 represents the steering shaft in the sense of this invention.

[0046] A rotary sensor 3 according to the invention is mounted on the steering column 2. This rotary sensor 3 detects steering commands introduced into the steering spindle 22 as the steering wheel 23 rotates. Figure 1 The text suggests that the text is indicative and in Figures 2 to 5 The diagram explains this in detail.

[0047] The steering input from the rotary sensor 3 is detected by the control unit in the form of an electrical control signal, i.e., a steering signal, which is transmitted to the electric steering actuator 5 via the electrical control line 4.

[0048] The steering actuator 5 has an electric motor-type linear drive device, such as a spindle drive device known per se. Thus, as indicated by the double arrows, the actuator rod 51 can move linearly according to the activation of the electric steering signal.

[0049] The actuator rod 51 is hinged to the steering knuckle of the steerable wheel 61 in a known manner via the tie rod 6.

[0050] According to the invention, the rotary sensor 3 is connected to the front end section 221, which is opposite to the steering wheel 23 in the driving direction of the vehicle having the steering spindle 22. Figure 1 In the view, the diagonal line points to the lower right. The forward direction of the longitudinal axis L is indicated by an arrow.

[0051] In the example shown, the rotary sensor 3 mounted on the steering spindle could also be used at other points in the steering system 1, for example, to detect the rotation of the pinion 25 in order to determine the position of the rack.

[0052] exist Figure 2 , Figure 3 , Figure 4 and Figure 5 In the illustration, the rotary sensor 3 is shown as a separate unit. Figure 2 It is a three-dimensional view of the front side, that is, it is tilted relative to the longitudinal direction of the longitudinal axis L, which is drawn with arrows. Figure 3 A three-dimensional view is shown, viewed from the rear along a diagonal line, which is in Figure 4 The middle section was partially disassembled. Figure 5 A three-dimensional view shows the longitudinal section along the longitudinal axis L.

[0053] The rotary sensor 3 has a can-shaped or cup-shaped housing 31 with an axially peripheral end wall 32 connected to a circumferential wall 33 that is hollow and cylindrical around axis A, and this circumferential wall 33 can also be referred to as the outer shell wall. According to the invention, the end wall 32 is designed to be continuously closed, especially in the region between the longitudinal axis L and axis A.

[0054] Within the housing 31, a ring gear 7 is rotatably mounted around axis A. The ring gear 7 has internal teeth extending coaxially around axis A, such as... Figure 4 and Figure 5 As can be seen, the internal gear section encloses the interior of the ring gear 7 using its axial passage. The front part of the internal gear section is closed in the longitudinal direction by the end wall 32, and on the opposite axial inner side by the disc-shaped inner wall 34. Therefore, the ring gear 7 is axially arranged between the end wall 32 and the inner wall 34.

[0055] exist Figure 4 In the illustration, the inner wall 34 is omitted for better overview. Two measuring wheels 71 and 72 are mounted in a freely observable interior, rotatable about their axes M1 and M2, and are engaged in a toothed manner within the internal teeth. Axes M1 and M2 are arranged radially parallel to axis A.

[0056] The two measuring wheels 71 and 72 have different numbers of teeth and each carries magnetic elements 73 and 74 that rotate together, as shown in... Figure 4 It can be seen in the image.

[0057] The inner wall 34 is secured to the end wall 32 by means of fasteners 35 extending axially through the interior. The fasteners 35 leading to the end wall 32 include molded pins, etc., and protrude axially into the interior along axis A. Figure 3 As can be seen, the inner wall 42 can be fixed to these fasteners.

[0058] Similar to end wall 32, the inner wall 34 in the central region of axis A is formed as a continuous closed structure.

[0059] According to the present invention, the interior of the ring gear 7 is defined and closed by the end wall 32, the inner wall 34, and the outer periphery extending inward to the inner teeth.

[0060] In the example, the longitudinal axis L of the steering spindle 20 is arranged radially parallel to the axis A of the ring gear 7, as shown in... Figure 3 and Figure 5 It can be easily seen in the middle.

[0061] In the front end section 221, a pinion 25 is mounted on the steering spindle 22. The pinion 25 engages with the internal teeth of the drive wheel 75 via its external teeth. The drive wheel 75 has an internal ring gear that rotates coaxially about axis A and is axially connected to the ring gear 7 via an annular gap 76 for co-rotation. The annular gap 76 extends coaxially about axis A and is formed between the inner wall 34 and the housing 31. Figure 5 As shown in the diagram. Therefore, the rotation of the steering spindle 22 about the longitudinal axis L is converted into the rotation of the drive wheel 75 and the ring gear 7 connected to the drive wheel 75.

[0062] The connecting element between the drive wheel 75 and the ring gear 7 can be achieved, for example, by means of a one-piece connection, such as by means of a one-piece plastic injection molded part. Alternatively, it is conceivable and possible to achieve a releasable connection between the steering spindle 22 and the ring gear 7, for example, by means of a form-fitting element, which is axially engaged through the annular gap 76.

[0063] The inner wall 34 may include a circuit board, i.e., a circuit board with conductive tracks made of insulating material, which serves as a carrier for electronic control circuitry. This may preferably be arranged internally on the inner surface facing the ring gear 7, and may also preferably have a measuring element 77 associated with magnetic elements 73 and 74, such as... Figure 5 As indicated in the document.

[0064] The ring gear 7 can be rotatably mounted on the inner wall 34, for example, in the illustrated example, the inner wall 34 is circular and axially engages in the coaxial recess of the ring gear 7. A similar axial support can be achieved by a coaxial protrusion 78 that axially protrudes from the end wall 32 and the ring gear 7 is rotatably mounted on the coaxial protrusion 78. The coaxial protrusion 78 can be molded onto the housing 31 in a one-piece manner.

[0065] The housing 31 may include a connecting device, such as a flange 79, for mounting on the steering column 2. The connecting device may also be molded onto the housing 31 in a one-piece manner. List of reference numerals in the attached figures 1. Steering System 2 steering columns 21 support units 22 steering spindle 221 End Section 23 steering wheel 24 housing units 25 pinions 3 Rotary Sensors 31 shell 32 end wall 33 Zhou Xiangbi 34 Inner Wall 35 Fasteners 4 control lines 5 steering actuators 51 actuator rod 6-bar 61 rounds 7. Ring Gear 71, 72 Measuring Wheels 73, 74 Magnetic components 75 drive wheels 76 Annular gap 77 Measuring Elements 78 protrusions 79 flange L longitudinal axis Axis A M1 axis M2 axis

Claims

1. A rotary sensor (3) for a steering system (1) of a motor vehicle, the rotary sensor (3) comprising a ring gear (7) rotatably mounted in a housing (31) about an axis (A), and internal teeth and a connecting element designed to connect to a steering shaft (22) rotatable about a longitudinal axis (L) of the steering shaft (22), in, The housing (31) has an axial end wall (32), an axial inner wall (34), and a coaxially extending circumferential wall (33), wherein the ring gear (7) is axially arranged between the end wall (32) and the inner wall (34), and is circumferentially enclosed by the circumferential wall (33) about the axis (A), and At least one measuring wheel (71, 72) having magnetic elements (73, 74) is rotatably mounted in the housing (31) and engages with the internal teeth of the ring gear (7) by means of the external teeth of the at least one measuring wheel (71, 72). The housing (31) contains a measuring element (77) that cooperates with the magnetic elements (73, 74) of the measuring wheels (71, 72). Its features are, The end wall (32) and the inner wall (34) are formed as a continuous closure within the interior enclosed by the inner teeth.

2. The rotary sensor according to claim 1, characterized in that, At least two measuring wheels (71, 72) are rotatably mounted in the housing (31), each of the at least two measuring wheels (71, 72) having a magnetic element (73, 74), and in each case, the external teeth of the at least two measuring wheels (71, 72) engage in the internal teeth of the ring gear (7), and wherein a measuring element (77) that cooperates with the magnetic elements (73, 74) of the measuring wheels (71, 72) is mounted in the housing (31).

3. The rotary sensor according to any one of the preceding claims, characterized in that, The ring gear (7) has an axial internal space defined by the internal teeth on the circumferential side.

4. The rotary sensor according to any one of the preceding claims, characterized in that, The ring gear (7) is axially sealed against the end wall (32) and / or the inner wall (34).

5. The rotary sensor according to any one of the preceding claims, characterized in that, The ring gear (7) is mounted in an axial support arrangement (78) on the end wall (32) and / or the inner wall (34).

6. The rotary sensor according to any one of the preceding claims, characterized in that, The inner wall (34) is rotatably inserted into the support recess of the ring gear (7).

7. The rotary sensor according to any one of the preceding claims, wherein, The inner wall (34) is connected to the end wall (32) via at least one connecting device (35) that passes axially through the interior.

8. The rotary sensor according to any one of the preceding claims, wherein, A coaxial, axially open annular gap (76) is formed around the outside of the inner wall (34).

9. The rotary sensor according to claim 8, wherein, The connecting element extends through the annular gap (76).

10. The rotary sensor according to the preceding claim, wherein, The shell (31) is can-shaped.

11. The rotary sensor according to any one of the preceding claims, wherein, The end wall (32) and the circumferential wall (33) are formed together as a single piece.

12. The rotary sensor according to any one of the preceding claims, wherein, The housing (31) has fasteners (79).

13. The rotary sensor according to any one of the preceding claims, wherein, The measuring wheels (71, 72) are mounted on the end wall (32).

14. The rotary sensor according to any one of the preceding claims, wherein, The inner wall (34) or the housing (31) has a circuit board.

15. A steering system (1) for a motor vehicle, the steering system (1) including a steering shaft (22) rotatable about a longitudinal axis (L) of the steering shaft, the steering shaft (22) being operatively connected to a rotary sensor (3) for detecting rotation. in, The rotary sensor (3) is formed according to any one of claims 1 to 14.

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