Cardan shaft system, steering system and motor vehicle

Abstract

A driveshaft system (1) of a steering system (2) of a motor vehicle (3), comprising a driveshaft (4) with a shaft section (5) and a driveshaft coupling (6) arranged on the shaft section (5), and a driveshaft tube (7) with a tube section (8) and a driveshaft tube coupling (9) arranged on the tube section (8), wherein the shaft section (5) has a longitudinal shaft axis (10) and the tube section (8) has a longitudinal tube axis (11), wherein at least one longitudinal shaft groove (12) parallel to the longitudinal shaft axis (10) is formed in the shaft section (5) and at least one longitudinal tube groove (13) parallel to the longitudinal tube axis (11) is formed in the tube section (8), further comprising a rolling bearing device (14) with rolling bearing bodies (15) which are inserted into the at least one longitudinal shaft groove (12) and the at least one longitudinal tube groove (13) for transmitting a steering torque from the driveshaft (4) engage the drive shaft tube (7), characterized in thatthat at least one locking device (16) is arranged in a rotationally fixed manner on the shaft section (5), the locking device having at least one first positive locking element (17) that engages at least partially in the at least one longitudinal groove (13) of the tube, wherein the at least one locking device (16) has at least one second positive locking element (18), wherein the second positive locking element (18) engages in the at least one longitudinal groove (12) of the shaft, wherein the at least one first positive locking element (17) and / or the at least one second positive locking element (18) have such an undersize that a clearance is formed with respect to the respective longitudinal groove (13) of the tube or longitudinal groove (12) of the shaft, and wherein the locking device (16) has a material that is so flexible that the locking device (16) is at least partially deformed when the steering torque is transmitted.

Description

[0001] The present invention relates to a driveshaft system of a steering system for a motor vehicle. Furthermore, the present invention relates to a steering system for a motor vehicle, wherein the steering system comprises a driveshaft system. Finally, the present invention relates to a motor vehicle with a steering system, wherein the steering system comprises a driveshaft system.

[0002] In motor vehicles, a steering system translates the driver's directional inputs into the steering position of the vehicle's steered wheels. Conventional steering systems consist of a steering wheel, a steering column, a driveshaft system, a steering gear, and a steering axle, all interconnected in such a way that a steering movement at the steering wheel results in a corresponding steering movement at the steering axle. The driveshaft system is located between the steering column and the steering gear and is designed to transmit steering torque from the steering column to the steering gear. Furthermore, driveshaft systems are designed to allow for height and / or angle adjustment of the steering column, and thus the steering wheel, to adapt to the driver's individual needs.

[0003] Conventional driveshaft systems consist of a driveshaft tube and a driveshaft partially enclosed within the tube and guided linearly along the tube's longitudinal axis. The steering wheel height can be adjusted relative to the steering column by axially displacing the driveshaft and driveshaft tube. Furthermore, the driveshaft and / or the driveshaft tube have a coupling to allow the steering wheel and steering column to pivot together. To transmit steering torque from the driveshaft to the driveshaft tube and to improve the relative linear movement of the driveshaft and driveshaft tube, driveshaft systems incorporate a rolling bearing assembly with rolling elements, such as a ball cage with balls, located between the driveshaft and the driveshaft tube. The rolling elements are guided linearly in grooves parallel to the tube's longitudinal axis in both the driveshaft and the driveshaft tube.Applying a force parallel to the longitudinal axis of the tube causes the rolling elements to roll in the grooves, resulting in a relatively linear displacement of the driveshaft and driveshaft tube. A steering torque generates a force that is transmitted from a groove wall of the driveshaft via the rolling element to a groove wall of the driveshaft tube. Thus, the driveshaft and driveshaft tube are rotationally fixed relative to each other.

[0004] DE 10 2015 102 183 A1 discloses a driveshaft system in which an axial locking washer is pressed onto a profile shaft and fixed to it by crimping. DE 10 2013 010 396 A1 discloses, as an alternative, an axial clamping ring which is fixed to a steering shaft by means of a fastening element. DE 10 2014 017 555 A1 discloses a steering shaft with a stop element fixed to a hollow shaft. DE 600 35 085 T2 discloses a telescopic shaft for motor vehicle steering columns with a locking element arranged in a rotationally fixed manner on a receiving element designed as a hollow shaft.

[0005] Conventional driveshaft systems, especially those with a ball cage, have the disadvantage that if the rolling bearing assembly is damaged, for example due to wear or an accident, the rolling bearings can fall out of their grooves and are therefore no longer available for transmitting steering torque. A rotational movement of the steering wheel can then no longer be transmitted to the steering gear, rendering the vehicle unmaneuverable and preventing it from driving itself to a repair shop.

[0006] It is therefore an object of the present invention to provide a driveshaft system, a steering system, and a motor vehicle that do not exhibit, or at least not fully exhibit, the disadvantages of the prior art. In particular, it is an object of the present invention to create a driveshaft system, a steering system, and a motor vehicle that, using simple and cost-effective means, ensure the transmission of a steering torque from the driveshaft to the driveshaft tube even when the rolling bearing assembly is damaged, thus enabling continued driving.

[0007] The aforementioned problem is solved according to the invention by the claims. Accordingly, the problem is solved by a driveshaft system of a steering system of a motor vehicle according to claim 1, by a steering system for a motor vehicle according to claim 8, and by a motor vehicle according to claim 9. Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings. Features and details described in connection with the driveshaft system according to the invention naturally also apply in connection with the steering system and the motor vehicle according to the invention, and vice versa, so that the disclosure of the individual aspects of the invention always makes, or can make, reciprocal references.

[0008] According to a first aspect of the invention, the problem is solved by a driveshaft system of a motor vehicle steering system. The driveshaft system comprises a driveshaft with a shaft section and a driveshaft coupling arranged on the shaft section, as well as a driveshaft tube with a tube section and a driveshaft tube coupling arranged on the tube section. The shaft section has a longitudinal axis and the tube section has a longitudinal axis, wherein at least one longitudinal groove parallel to the shaft's longitudinal axis and at least one longitudinal groove parallel to the tube's longitudinal axis are formed in the shaft section and in the tube section. Furthermore, the driveshaft system comprises a rolling bearing assembly with rolling bearing elements which engage in the at least one longitudinal groove in the shaft and the at least one longitudinal groove in the tube to transmit a steering torque from the driveshaft to the driveshaft tube.According to the invention, at least one locking device is arranged in a rotationally fixed manner on the shaft section, the locking device having at least one first positive locking element that engages at least partially in the at least one longitudinal groove of the tube. The at least one locking device has at least one second positive locking element, the second positive locking element engaging in the at least one longitudinal groove of the shaft.

[0009] The driveshaft has a shaft section with a preferably substantially round cross-section and a longitudinal shaft axis. The shaft section can be solid or have an internal cavity. A driveshaft coupling is arranged at an end of the shaft section pointing away from the driveshaft tube. The driveshaft coupling is preferably designed as a coupling fork. Preferably, the driveshaft coupling is designed for mechanically coupling the driveshaft to a steering column, so that the driveshaft and steering column can pivot relative to each other. At least one longitudinal shaft groove is formed on an outer surface that encloses or at least substantially encloses the longitudinal shaft axis and faces away from the longitudinal shaft axis. This groove extends parallel to the longitudinal shaft axis.At least one rolling bearing body of a rolling bearing device is arranged in at least one longitudinal shaft groove and is movable linearly along the shaft groove. A force caused by a steering torque can be transmitted to the rolling bearing body transversely to the shaft longitudinal axis via a side wall of the shaft groove.

[0010] The driveshaft tube has a pipe section with a preferably cross-section such that the shaft section of the driveshaft can be inserted into the pipe section in a form-fitting manner, or substantially in a form-fitting manner. The pipe section therefore has an inner recess that corresponds to, or at least substantially corresponds to, an outer contour of the shaft section. A driveshaft tube coupling is arranged at an end of the pipe section pointing away from the driveshaft. The driveshaft tube coupling is preferably designed as a coupling fork. Preferably, the driveshaft tube coupling is designed for mechanically coupling the driveshaft tube to a steering gear, so that the driveshaft tube and steering gear can pivot relative to each other. On an outer surface that encloses the longitudinal axis of the tube, or...The shaft is at least substantially enclosed and faces away from the longitudinal axis of the tube. At least one longitudinal groove is formed in the tube, extending parallel to the longitudinal axis. At least one rolling bearing body of the rolling bearing assembly is arranged in the at least one longitudinal groove and is movable linearly along the longitudinal groove. The force transmitted to the rolling bearing body by the steering torque, transverse to the longitudinal axis of the shaft, is transmitted from the rolling bearing body to a side wall of the longitudinal groove, also transverse to the longitudinal axis of the tube. The longitudinal axis of the shaft and the longitudinal axis of the tube are coaxial to each other in the assembled state of the driveshaft system.

[0011] Preferably, the shaft section has several longitudinal shaft grooves and the tube section has several longitudinal tube grooves, preferably arranged such that each shaft longitudinal groove is opposite a longitudinal tube groove. The rolling bearing assembly preferably has several rolling bearing elements for each shaft longitudinal groove-tube longitudinal groove pair to ensure the most uniform possible distribution of the steering torque forces. Preferably, the rolling bearing assembly is designed as a ball cage in which a plurality of balls are held as rolling bearing elements.

[0012] At least one locking device is arranged on the shaft section in a rotationally fixed manner. Preferably, the driveshaft system has exactly one locking device, which may be formed in one piece or in multiple parts. In this context, "rotationally fixed" means that a rotation of the shaft section causes a rotation of the locking device that corresponds to, or at least substantially corresponds to, the rotation of the shaft section. The locking device can be held on the shaft section, for example, by means of a press fit, a keyway connection, or the like. Furthermore, the locking device is preferably secured against sliding off the shaft section in the direction of the shaft's longitudinal axis, for example, by means of a snap ring, a screw, a cotter pin, or the like.The connection between the shaft section and the locking device is designed such that the steering torque can be transmitted from the shaft section to the locking device without causing a permanent relative rotation between the shaft section and the locking device. Within the scope of the invention, it is preferred that the driveshaft system is designed to also transmit the steering torque from the driveshaft tube to the driveshaft.

[0013] The first positive locking element of the locking device engages in the longitudinal groove of the tube. This engagement is such that, in the absence of a rolling bearing device or bearing body, the steering torque can be transmitted to the longitudinal groove of the tube via the first positive locking element. The first positive locking element preferably has a shape and size such that linear relative displacement of the driveshaft and driveshaft tube is not, or not significantly, impeded. Preferably, the positive locking element has a sliding surface or coating that facilitates such displacement.

[0014] The driveshaft and the driveshaft tube are coupled to each other via the first and second positive locking elements such that the steering torque can be transmitted from the driveshaft to the driveshaft tube via these elements. Preferably, the first and second positive locking elements are formed in one piece or together form a single positive locking element. The single positive locking element is, for example, pin-shaped, cylindrical, spherical, or similarly shaped. It is preferred that the single positive locking element extends parallel to the longitudinal axis of the shaft in the assembled state. Preferably, the single positive locking element is held by a holding device or is integrally formed with it. The holding device and the single positive locking element together preferably form the locking device.A second positive locking element has the advantage that mounting the locking device onto the shaft section is made easier and a reliable transmission of the steering torque from the drive shaft to the locking device is ensured.

[0015] The inventive drive shaft system has the advantage over prior art drive shaft systems that the steering torque can still be transmitted from the drive shaft to the drive shaft tube even if the rolling bearing assembly is damaged to such an extent that the steering torque cannot be transmitted from the drive shaft to the drive shaft tube via the rolling bearing assembly. This advantage is achieved by the locking device in a simple, cost-effective, and reliable manner. The locking device thus provides a redundant means for transmitting the steering torque. In this way, a motor vehicle remains maneuverable even with a defective rolling bearing assembly in the drive shaft system and can therefore be driven by the driver to a workshop for repair or replacement of the drive shaft system or the rolling bearing assembly without the need for expensive towing.

[0016] According to the invention, in a driveshaft system, it is preferred that the at least one locking device is designed as a crown, which is arranged on a free end face of the shaft section. The crown is, for example, mounted or placed onto the open end face of the shaft section in the direction of the shaft's longitudinal axis. Preferably, the crown projects laterally beyond the shaft section in a radial direction with respect to the shaft's longitudinal axis. More preferably, the crown is held on the shaft section at least by means of an interference fit. It is preferred that the shaft's longitudinal groove extends to and is open towards the free end face, and preferably that second positive-locking sections of the crown engage in the shaft's longitudinal groove. A crown has the advantage that it can be manufactured and installed using simple and cost-effective means.Mounting on the free end face ensures that steering torque transmission via the locking device can occur even when the shaft section is extended far out of the pipe section, as this device only disengages from the pipe section when the shaft section is completely pulled out of the pipe section.

[0017] According to a preferred embodiment of the invention, the crown is fixed to the shaft section by crimping. For this purpose, the crown preferably has a base with an opening through which a portion of the free end face of the shaft section is passed and deformed in such a way that it engages behind the opening. Alternatively or additionally, the crown can be secured to the shaft section, for example, by a locking screw, a locking pin, a snap ring with a groove, gluing, welding, or the like. In this way, a secure hold of the crown on the shaft section is ensured using simple and cost-effective means.

[0018] It is preferred that the at least one locking device is designed as a sleeve, ring, or ring segment, and that the at least one locking device is arranged on a longitudinal axis section of the shaft section. The locking device is preferably held on the shaft section by an interference fit. The locking device can be mounted or secured on the shaft section, for example, by shrink-fitting or press-fitting. Additionally or alternatively, axial securing of the locking device by means of a screw, a snap ring, or the like may be provided. For example, the shaft section may have a circumferential or substantially circumferential groove into which the locking device is inserted. With such a groove, a two-part locking device is preferred, as it is easier to mount and is held on the shaft section by the tube section.The driveshaft system can, for example, have two locking devices arranged on the longitudinal axis section, or one locking device arranged on the longitudinal axis section and one on the free end face. Such a locking device has the advantage that the steering torque can be transmitted using simple and cost-effective means.

[0019] Preferably, the locking device and / or the rolling bearing device are secured against axial displacement along the longitudinal axis of the shaft in at least one direction by means of at least one retaining ring and / or at least one locking pin. According to the invention, it is preferred that the shaft section has a corresponding design for holding the at least one retaining ring and / or at least one locking pin. In this way, the locking device can be fixed to the shaft section simply and cost-effectively.

[0020] According to the invention, it is particularly preferred that the at least one first positive locking element and / or the at least one second positive locking element has such an undersized dimension that a clearance is formed with respect to the respective longitudinal groove in the tube or shaft. This means that the at least one first positive locking element and / or the at least one second positive locking element is slightly movable laterally in the longitudinal groove in the tube or shaft. Thus, when the driveshaft and driveshaft tube are rotated, at least a slight relative rotation of the driveshaft and driveshaft tube is possible if the rolling bearing assembly is missing or defective. Such relative rotation has the advantage that the steering feel with an intact rolling bearing assembly differs noticeably for the driver from the steering feel with a defective or missing rolling bearing assembly. The driver can therefore immediately detect a defective rolling bearing assembly and arrange for repairs.

[0021] Additionally or alternatively, it is preferred that the locking device comprises a compliant, particularly elastic, material, such as an elastomer, such that it is at least partially deformed when the steering torque is transmitted. Preferably, the first positive locking element and / or the second positive locking element comprises or is formed from a compliant material. In this way, a driveshaft system can be provided with simple or cost-effective means that offers the driver a noticeably different steering feel with an intact and a defective rolling bearing assembly. The driver can thus immediately detect a defective rolling bearing assembly and arrange for repairs.

[0022] According to a second aspect of the invention, the problem is solved by a steering system for a motor vehicle. The steering system comprises a steering column and a steering gear, wherein the steering column is coupled to the steering gear via a coupling device for transmitting a steering torque. According to the invention, the coupling device is designed as a driveshaft system according to the invention.

[0023] The steering system according to the invention has the same advantages as already described above for a driveshaft system according to the first aspect of the invention. Accordingly, the steering system according to the invention has the advantage over steering systems known from the prior art that the steering torque can still be transmitted from the driveshaft to the driveshaft tube even if the rolling bearing assembly is damaged to such an extent that the steering torque cannot be transmitted from the driveshaft to the driveshaft tube via the rolling bearing assembly. This advantage is achieved by the safety device in a simple, cost-effective, and reliable manner. The safety device thus provides a redundant means for transmitting the steering torque. In this way, a motor vehicle remains maneuverable even with a defective rolling bearing assembly in the driveshaft system and can therefore be driven by the driver without the need for expensive towing to a workshop for repair.The replacement of the drive shaft system or the rolling bearing assembly can be carried out.

[0024] According to a third aspect of the invention, the problem is solved by a motor vehicle with at least one steerable wheel. According to the invention, the motor vehicle has a steering system according to the invention for steering the at least one wheel, which is mechanically coupled to the at least one wheel.

[0025] The motor vehicle according to the invention has the same advantages as already described above for a driveshaft system according to the first aspect of the invention and a steering system according to the second aspect of the invention. Accordingly, the motor vehicle according to the invention has the advantage over motor vehicles known from the prior art that the steering torque can still be transmitted from the driveshaft to the driveshaft tube even if the rolling bearing assembly is damaged to such an extent that the steering torque cannot be transmitted from the driveshaft to the driveshaft tube via the rolling bearing assembly. This advantage is achieved by the locking device in a simple, cost-effective, and reliable manner. The locking device thus provides a redundant means for transmitting the steering torque.In this way, a motor vehicle with a defective rolling bearing device in the drive shaft system can still be maneuvered and can therefore be driven by the driver to a workshop for repair or replacement of the drive shaft system or the rolling bearing device without the need for expensive towing.

[0026] A driveshaft system, steering system, and motor vehicle according to the invention are explained in more detail below with reference to the drawings. Identical components are provided with the same reference numerals. The drawings schematically show: Fig. 1 in a perspective exploded view a preferred first embodiment of a cardan shaft system according to the invention; Fig. 2 in a perspective exploded view a preferred second embodiment of the cardan shaft system according to the invention; Fig. 3 in a perspective exploded view a preferred third embodiment of the cardan shaft system according to the invention; Fig. 4 in a side view the third embodiment of the cardan shaft system according to the invention Fig. 3; Fig. 5 in a perspective exploded view a preferred fourth embodiment of the cardan shaft system according to the invention; Fig. 6 in a perspective view a variant of a safety device according to the invention; Fig. 7 in a side view a steering system according to the invention; and Fig. 8 in a top view of a motor vehicle according to the invention.

[0027] In Fig. Figure 1 schematically depicts a first embodiment of the driveshaft system 1 according to the invention in a perspective exploded view. The driveshaft system 1 comprises a driveshaft 4 with a shaft section 5 and a driveshaft coupling 6 arranged at one end of the shaft section 5. The shaft section 5 has a longitudinal shaft axis 10 and a longitudinal shaft groove 12 formed parallel to the longitudinal shaft axis 10. Furthermore, the driveshaft system 1 comprises a driveshaft tube 7 with a tube section 8 and a driveshaft tube coupling 9 arranged at one end of the tube section 8. The tube section 8 has a longitudinal tube axis 11 and a longitudinal tube groove 13 formed parallel to the longitudinal tube axis 11. For the transmission of steering torque, the driveshaft system 1 comprises a rolling bearing device 14 designed as a bearing cage with spherically shaped rolling bearing bodies 15.The rolling bearing assembly can be secured against falling out of the tube section 8 by means of a retaining ring 23. Furthermore, the cardan shaft system has a locking device 16 with first positive locking elements 17 for engaging in a longitudinal groove 13 in the tube and second positive locking elements 18 for engaging in a longitudinal groove 12 in the shaft. The locking device 16 is designed as a crown 19 and can be fixed to a free end face formed at one end of the shaft section 5 opposite the cardan shaft coupling 6, in particular by riveting.

[0028] In Fig. Figure 2 schematically depicts a second embodiment of the cardan shaft system 1 according to the invention in a perspective exploded view. The cardan shaft system 1 comprises a cardan shaft 4 with a shaft section 5 and a cardan shaft coupling 6 arranged at one end of the shaft section 5. The shaft section 5 has a longitudinal shaft axis 10 and a longitudinal shaft groove 12 formed parallel to the longitudinal shaft axis 10. Furthermore, the cardan shaft system 1 comprises a cardan shaft tube 7 with a tube section 8 and a cardan shaft tube coupling 9 arranged at one end of the tube section 8. The tube section 8 has a longitudinal tube axis 11 and a longitudinal tube groove 13 formed parallel to the longitudinal tube axis 11. For the transmission of steering torque, the cardan shaft system 1 comprises a rolling bearing device 14 designed as a bearing cage with spherically shaped rolling bearing bodies 15.A retaining ring 23 secures the rolling bearing assembly against falling out of the tube section 8. Furthermore, the cardan shaft system has a locking device 16 with first positive locking elements 17 for engaging in a longitudinal groove 13 of the tube and second positive locking elements 18 for engaging in a longitudinal groove 12 of the shaft. The locking device 16 is formed from two ring segments 22, which can be received in a circumferential groove 28 of the longitudinal shaft section 5 and are thus secured against slipping along the longitudinal axis 10 of the shaft.

[0029] In Fig. Figure 3 schematically depicts a third embodiment of the cardan shaft system 1 according to the invention in a perspective exploded view. The cardan shaft system 1 comprises a cardan shaft 4 with a shaft section 5 and a cardan shaft coupling 6 arranged at one end of the shaft section 5. The shaft section 5 has a longitudinal shaft axis 10 and a longitudinal shaft groove 12 formed parallel to the longitudinal shaft axis 10. Furthermore, the cardan shaft system 1 comprises a cardan shaft tube 7 with a tube section 8 and a cardan shaft tube coupling 9 arranged at one end of the tube section 8. The tube section 8 has a longitudinal tube axis 11 and a longitudinal tube groove 13 formed parallel to the longitudinal tube axis 11. For the transmission of steering torque, the cardan shaft system 1 comprises a rolling bearing device 14 designed as a bearing cage with spherically shaped rolling bearing bodies 15.The rolling bearing assembly can be secured against slipping off the shaft section 5 by means of a retaining ring 23. Furthermore, the cardan shaft system has a locking device 16 with first positive locking elements 17 for engaging in a longitudinal groove 13 of the tube and second positive locking elements 18 for engaging in a longitudinal groove 12 of the shaft. The locking device 16 is designed as a sleeve 20 and can be secured against falling out of the tube section 8 by means of a further retaining ring 23. Fig. Figure 4 shows the third embodiment of the inventive shaft system 1 schematically in the assembled state in a side view.

[0030] In Fig. Figure 5 is a fourth embodiment of the driveshaft system 1 according to the invention, schematically depicted in a perspective exploded view. The driveshaft system 1 comprises a driveshaft 4 with a shaft section 5 and a driveshaft coupling 6 arranged at one end of the shaft section 5. The shaft section 5 has a longitudinal shaft axis 10 and a longitudinal shaft groove 12 formed parallel to the longitudinal shaft axis 10. Furthermore, the driveshaft system 1 comprises a driveshaft tube 7 with a tube section 8 and a driveshaft tube coupling 9 arranged at one end of the tube section 8. The tube section 8 has a longitudinal tube axis 11 and a longitudinal tube groove 13 formed parallel to the longitudinal tube axis 11. For the transmission of steering torque, the driveshaft system 1 comprises a rolling bearing device 14 designed as a bearing cage with spherically shaped rolling bearing bodies 15.The rolling bearing assembly can be secured against slipping off the shaft section 5 by means of a retaining ring 23. Furthermore, the drive shaft system has a locking device 16 with first positive locking elements 17 for engaging in a longitudinal groove 13 of the tube and second positive locking elements 18 for engaging in a longitudinal groove 12 of the shaft. The locking device 16 is designed as a sleeve 20 and can be secured against falling out of the tube section 8 by means of a further retaining ring 23. An additional locking pin 24 is also arranged on the sleeve 20 for axially securing the sleeve 20 to the tube section 8.

[0031] Fig. Figure 6 schematically shows a variant of a locking device 16 according to the invention in a perspective view. The locking device 16 is designed as a ring 21. The locking device 16 has first positive locking elements 17 for engaging in a longitudinal groove 13 of the tube and second positive locking elements 18 for engaging in a longitudinal groove 12 of the shaft. The ring 21 has a circumferentially arranged and circumferential lamellar locking element 27 for engaging in a circumferential inner groove of a tube section 8 of a driveshaft tube 7, thus providing axial locking of the locking device 16 to the tube section 8.

[0032] Fig. Figure 7 schematically shows a side view of a steering system 2 according to the invention. The steering system 2 has a steering column 25 which is pivotably coupled to a driveshaft coupling 6 of a driveshaft system 1 of the steering system 2 according to the invention. The driveshaft coupling 6 is fixed to a free end of a shaft section 5 of the driveshaft system 1. The shaft section 5 and the driveshaft coupling 6 are components of a driveshaft 4 of the driveshaft system 1. The shaft section 5 is axially displaceable within a tube section 8 of a driveshaft tube 7 of the driveshaft system 1. A driveshaft tube coupling 9 of the driveshaft tube 7 is fixed to a free end of the tube section 8. The driveshaft system 1 is pivotably coupled to a steering gear 26 of the steering system 2 via the driveshaft tube coupling 9.

[0033] In Fig.Figure 8 shows a schematic top view of a motor vehicle 3 according to the invention. The motor vehicle 3 has two steerable wheels 29 which can be steered by means of a steering system 2 according to the invention. Reference symbol list 1 Cardan shaft system 2 Steering system 3 Motor vehicle 4 Cardan shaft 5 shaft section 6 Cardan shaft coupling 7 Cardan shaft tube 8 Pipe section 9 Cardan shaft tube coupling 10 Shaft longitudinal axis 11 Pipe longitudinal axis 12 Shaft longitudinal groove 13 Pipe longitudinal groove 14 Rolling bearing device 15 rolling bearing bodies 16 Safety device 17 first positive locking element 18 second positive locking element 19 crowns 20 sleeve 21 Ring 22 ring segment 23 retaining ring 24 safety pin 25 Steering column 26 Steering gear 27 Lamella locking mechanism 28 circumferential grooves 29 steerable wheel

Claims

[1] A driveshaft system (1) of a steering system (2) of a motor vehicle (3), comprising a driveshaft (4) with a shaft section (5) and a driveshaft coupling (6) arranged on the shaft section (5), and a driveshaft tube (7) with a tube section (8) and a driveshaft tube coupling (9) arranged on the tube section (8), wherein the shaft section (5) has a shaft longitudinal axis (10) and the tube section (8) has a tube longitudinal axis (11), wherein at least one shaft longitudinal groove (12) parallel to the shaft longitudinal axis (10) and at least one tube longitudinal groove (13) parallel to the tube longitudinal axis (11) is formed in the shaft section (5), further comprising a rolling bearing device (14) with rolling bearing bodies (15) which are inserted into the at least one shaft longitudinal groove (12) and the at least one tube longitudinal groove (13) for transmitting a steering torque of the drive shaft (4) engages the drive shaft tube (7), characterized by, that at least one locking device (16) is arranged in a rotationally fixed manner on the shaft section (5), which has at least one first positive locking element (17) that engages at least partially in the at least one longitudinal groove (13) of the tube, wherein the at least one locking device (16) has at least one second positive locking element (18), wherein the second positive locking element (18) engages in the at least one longitudinal groove (12) of the shaft, wherein the at least one first positive locking element (17) and / or the at least one second positive locking element (18) have such an undersize that a clearance is formed with respect to the respective longitudinal groove (13) of the tube or longitudinal groove (12) of the shaft, and wherein the locking device (16) has such a compliant material that the locking device (16) is at least partially deformed when the steering torque is transmitted. [2] Cardan shaft system (1) according to claim 1, characterized by, that the at least one locking device (16) is designed as a crown (19) which is arranged on a free end face of the shaft section (5). [3] Cardan shaft system (1) according to claim 2, characterized by , that the crown (19) is fixed to the shaft section (5) by crimping. [4] Cardan shaft system (1) according to any one of the preceding claims, characterized by , that the at least one locking device (16) is designed as a sleeve (20), ring (21) or ring segment (22), wherein the at least one locking device (16) is arranged on a longitudinal axis section of the shaft section (5). [5] Cardan shaft system (1) according to claim 4, characterized by , that the locking device (16) and / or the rolling bearing device (14) is secured against axial displacement along the shaft longitudinal axis (10) in at least one direction by means of at least one retaining ring (23) and / or at least one locking pin (24). [6] Steering system (2) for a motor vehicle (3), comprising a steering column (25) and a steering gear (26), wherein the steering column (25) is coupled to the steering gear (26) via a coupling device for the transmission of a steering torque, characterized by , that the coupling device is designed as a cardan shaft system (1) according to one of the preceding claims. [7] Motor vehicle (3) with at least one steerable wheel, characterized by , that the motor vehicle (3) has a steering system (2) according to claim 6 for steering the at least one wheel, which is mechanically coupled to the at least one wheel.

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