FR2896469A1 - Steering shaft for steering wheel of motor vehicle, has helicoidal compression spring arranged on countershaft, exerting axial force defined on upper and lower pinions of countershaft so that pinions tend to move away from one another - Google Patents

Abstract

The shaft has a countershaft (9) including a fixed steering hub (3) that is integrally mounted on a hub spindle (26) with a cable channel (4) that receives a cable (15) to the hub. A steering wheel rim (1) is concentrically arranged with the hub, where the rim is mounted on the countershaft by a wheel rim shaft (17) and its bearings (18a, 18b). A helicoidal compression spring (24) arranged on the countershaft, exerts an axial force defined on upper and lower pinions (25a, 25b) of the countershaft so that the pinions tend to move away from one another.

Description

STEERING SHAFT FOR STEERING WHEEL WITH FIXED STEERING HUB

  The invention relates to a steering shaft for a steering wheel comprising a fixed steering hub and a steering hub mechanism comprising a deflection shaft, in which the fixed steering hub is disposed integrally in rotation on a hub axle provided with a cable channel, and which comprises a wheel rim substantially concentric with the axis of rotation of the hub axle and movable in rotation, and which is integrally connected in rotation to a flywheel rim shaft which receives the hub axle, and is constituted by a hollow shaft and which has, at its end remote from the flywheel rim, an external toothing which is engaged with a first gear pinion. which is mounted together with a second idler gear on a idler shaft and is integral with the first idler, the second idler gear being engaged with a idler gear steering mechanism which is integrally rotated on a steering mechanism shaft.

  The steering wheels for motor vehicles that are usual until now are most often solely composed of a steering wheel rim which is connected by means of spokes to a steering hub which, for its part, is integrally connected in rotation to a steering shaft. As additional functional elements of these steering wheels, it is frequently provided exclusively keys for the actuation of the horn, the electrical connection between the horn button and fixed components of the vehicle being most often obtained by simple slip rings. Moreover, in recent years, the steering wheels are equipped as standard with air bags, the transmission of the signal being performed again by means of sliding contact rings, by means of volute springs or by opto-optic processes. electric or induction-based. 2

  In recent times, a growing number of other control elements, for example for the control of a car radio, a radiotelephone or a multimedia unit, are additionally mounted on the steering wheel. This increases both the quantity of signals to be transmitted and the conditions required for the security of the transmission and the quality of the transmission. Although these conditions can most often be met satisfactorily with the means described above, this implies a significant expenditure.

  Unfortunately, the steering wheels with steering hub rotated have disadvantages due to their principle, On the one hand, it is not possible to mount an asymmetric safety airbag since the instantaneous rotation angle of the steering wheel direction when the air bag is triggered can not be taken into account and the advantages of asymmetric air bags, which are provided by their principle, can easily have the opposite result. On the other hand, the integration of displays in the steering hub is lirnited to simple lights and symbols symbols illuminated because, when the hub of the steering wheel is rotated by more than 45, for example, relative to the position neutral, complex information can no longer be reliably captured by the driver or because it distracts the driver from the traffic to an unacceptable degree.

  This is why steering wheels have been developed which comprise a fixed steering hub relative to the vehicle. These flywheels in principle offer the possibility of using asymmetric airbags, to increase the safety of the occupants, as well as to integrate in the steering hub information presentations of almost any kind. for example by freely programmable displays. With a suitable construction, it is also possible to create a direct cable connection between fixed elements of the vehicle and the fixed steering hub without having to resort to volute springs or similar solutions.

  A fixed steering hub is already known from French patent FR 2 815 318 B1 and the corresponding documents EP 1 199 243 A1 and JP 2002 178 932 A. The rim of this steering wheel is connected by spokes to a toothed ring. inner wheel arranged concentrically around the center of the fixed steering hub and which meshes with a gear wheel placed inside this ring and which transmits the rotational movement of the steering wheel rim to a steering mechanism shaft.

  In principle, there is a transmission of the rotational movement of the rim of the steering wheel with acceleration, so that it is not possible to use identical steering shafts and / or steering mechanisms in vehicles with and without a fixed steering hub while maintaining the same steering behavior. Furthermore, the space available for a cable passage leading to the fixed steering hub is quite limited, so that one can come up against difficulties in the case of mounting pre-assembled plug cables.

  Also in principle, in this technical solution, there is a shift between the center of the rim of the steering wheel and the shaft of the steering mechanism. It is not possible to incorporate auxiliary power steering assistance because of the limited space requirements and the layout of the steering gear mechanism components but, on the contrary, this assistance must be added, for example on the next part of the steering mechanism shaft. Because of the low rotational speeds of this shaft, this implies that a torque must be introduced into the shaft of the steering mechanism that is all the stronger, so that in general it is necessary to provide an intermediate mechanism, which translates into additional costs and weight and requires space.

  French patent FR 2 827 561 B1 discloses a steering wheel with a fixed steering hub in which the rotational movement of a steering wheel rim is transmitted to a gear wheel via a hollow shaft. In the hollow shaft is rotatably mounted a fixed axis which carries the steering hub and which, for its part, has a bore through which it can bring cables, for example, to the fixed steering hub. The toothed wheel of the hollow shaft meshes with the gear of a countershaft whose second gear meshes with a toothed wheel of the steering mechanism shaft. The steering mechanism shaft is here arranged coaxially with the hollow shaft. With a construction of this kind, it is possible to obtain, according to the direction of rotation and the angle of rotation applied to turn the steering wheel, an identical rotational movement on the steering mechanism shaft and, therefore, to use identical steering mechanisms for vehicle equipment with and without fixed steering hubs. In fact, here, the space available for a cable passage leading to the fixed steering hub is very limited.

  Canadian patent CA 1 318 833 describes a similar technical solution but which is characterized by a considerably increased free space for the passage of the cables leading to the fixed steering hub.

  The German publication DE 37 37 165 A1 and the European patent application published under the corresponding N EP 0 314 887 A1 describe a similar construction, as well as other variants which are based, on the one hand, on a spiral used to maintaining the steering hub in the steering wheel and, secondly, on conical wheel pairs on the periphery of the steering hub or on an obliquely oscillating wheel, which rotates on the steering hub.

  A common point to the representative solutions of the kind of documents FR 2 827 161 B1, CA 1 318 833 and DE 37 37 165 A1 is that they do not describe particular provisions that aim to make the steering hub mechanism particularly lacking. However, a weak set of tooth flanks is one of the central conditions that must be fulfilled on a mechanism of this kind. Already in traditional vehicles having a steering hub but without a fixed steering hub, it is observed, particularly after a few years of operation that the directions must be repaired, in a complicated and expensive operation, because of a too much great game and imprecise and soft leadership behavior that results. Since these games and adjustment defects can accumulate on the entire drive train from the rim of the steering wheel to the steering wheels, games, even small, introduced in addition by a steering hub mechanism can have the effect that ultimately the entire management has become unfit to meet the imposed specifications.

  Faced with this background, the invention aims to create a steering shaft for a steering wheel having a fixed steering hub and a steering hub mechanism equipped with a return shaft which is distinguished by a game reduced steering hub mechanism. Moreover, the game must be able to be set and caught with simple means, or even be automatic catch-up.

  The term "return shaft" refers here, not exclusively to shaft arrangements in which a torque is transmitted from a first shaft to a second shaft, coaxial with the first shaft, via a shaft of referral disposed in an assembly with axes parallel to the first shaft. On the contrary, it also covers non-coaxial arrangements of the first and second shafts and provisions of the first and second shafts and / or the countershaft which are not parallel axes.

  The solution to this problem is provided by a steering shaft for a steering wheel comprising a fixed steering hub and a steering hub mechanism comprising a deflection shaft as defined in the preamble and characterized in that the deflection shaft and / or the countershaft pinions disposed on the countershaft, and / or their bearings, comprise means arranged to reduce the play of the steering hub mechanism, or that such means are arranged to act on them. .

  The invention is based on the knowledge that by using a steering hub mechanism with a return shaft, the latter, or the teeth provided on the latter, are particularly well suited, thanks to its or their geometric position, to effectively reduce to a minimum a set of tooth flanks in all the teeth of the steering hub mechanism, and to make the set of tooth flanks adjustable or capable of automatic adjustment using simple means.

  Accordingly, the invention is based on a steering shaft for a steering wheel with a fixed steering hub and a steering hub mechanism with a countershaft, in which the fixed steering hub is integrally rotatably mounted on a hub axle provided with a cable channel. The steering shaft or steering wheel has a rotating flywheel rim arranged substantially concentrically with the axis of rotation of the hub axle. This rim is integrally connected in rotation to a flywheel rim shaft receiving the hub axle and constituted by a hollow shaft. The flywheel rim shaft has an external toothing at its end remote from the flywheel rim, but a toothed wheel rotatably disposed on the flywheel rim shaft naturally represents a technically equivalent solution.

  The outer toothing is engaged with a first idler pinion which is mounted together with a second idler pinion on the idler shaft, and these pinions are rotationally integral with each other. The second countershaft gear is engaged with a gear wheel of the steering gear shaft, which is rotatably disposed on a steering mechanism shaft. Steering hub mechanisms are already known from DE 37 37 465 A1, CA 1 318 833 and FR 2 827 561 B1. 7

  To solve the problem, it is provided that the countershaft and / or the countershaft gear mounted on the countershaft and / or their bearings comprise means for reducing the play of the hub mechanism of direction, or that such means act on them, for example in the form of countershaft pinions made in the form of conical wheels and / or in the form of a floating mount of the countershaft and / or in the form of at least one return shaft spring axially biasing one of the two bevel wheels.

  According to a first embodiment, it is provided that the deflection shaft is mounted to rotate freely with a degree of freedom in translation in at least one return shaft bearing, said return shaft being prestressed by at least one elastic element. towards the steering wheel rim shaft and / or the steering mechanism shaft.

  The floating assembly can be obtained in a simple and inexpensive manner by the fact that at least one return shaft bearing, preferably the two countershaft bearings is or are each mounted in an elongated hole, to which case, of course, for example a bushing may be interposed between the outer ring of the bearing and the elongate hole, for the improvement of the service life of the bearings.

  In many cases of application, the flywheel rim shaft and the steering mechanism shaft will be arranged coaxially and the countershaft will be parallel axes relative to the first. In such a case, the direction of the degree of freedom in translation is most often directly perpendicular both to the reference shaft and the common axis of the steering mechanism shaft and the rim shaft of wheel.

  However, this basic configuration makes it possible, even in the infrequent case where the steering wheel rim shaft and the steering mechanism shaft should not be coaxial and possibly not even parallel axes with respect to the other, to choose as direction of the degree of freedom in translation, for an upper bearing and for a lower bearing of the deflection shaft, each time a different direction oriented towards that of the flywheel rim shaft and the the steering mechanism shaft, which is the closest to the bearing of the flywheel rim shaft, the optimum direction of the degree of freedom also depending in this case on the kind of toothing chosen and which can be determined individually in each case.

  Naturally, in this basic variant, it would be difficult to prestress the entire deflection shaft in the desired direction by a single spring since there is not a common point of engagement on the mechanism shaft of management. Therefore, according to a development of the first embodiment of the invention, there is provided a shaft sleeve bearing in which the countershaft is rotatably mounted by means of thrust shaft bearings. upper and lower. The thrust bearing bushing is then mounted floating, preferably in the housing of the steering hub mechanism, with a degree of freedom in translation towards the flywheel rim shaft and / or the shaft. steering mechanism, or prestressed by at least one elastic element in the direction of the steering wheel rim shaft and / or the steering mechanism shaft.

  A second basic embodiment of the invention provides that at least one of the pinions of the countershaft is conical and that the toothing which is engaged with the countershaft gear, with the rim shaft of externally toothed flywheel or with the gear wheel of the steering mechanism shaft is of corresponding shape. The distance between the pinions of the countershaft can be adjusted at least by adjusting the axial position of the pinion gear of the countershaft on the countershaft. The decisive point here is the fact that by means of the spacing distance of the gears of the countershaft, thanks to the conical shape of the toothing, it is possible to establish a desired set of tooth flanks. To eliminate the play on areas of attack of the teeth, it is necessary that the two gears are conical.

  The notion of conic should not be interpreted in its strict geometric sense, but should be the one used for conical wheels. Thus, any body of revolution having a constant plot with respect to the axis of rotation is in this sense a conical body if its radius varies along the axis of rotation and is therefore not a cylinder. In other words, the line of junction between the upper periphery and the lower periphery of the bevel wheel does not have to be a straight line.

  When the at least two conical teeth which are engaged at the same time have a curved shape, relative to their axis, an advantageous bearing surface of the toothing is obtained and the possibility of compensating small differences in angle between the axes concerned.

  Another variant of this embodiment of the invention provides that the at least two conical teeth in engagement have a hypoid toothing or a beveloid toothing. In this way, a steering hub mechanism of this kind can even be constructed with axes that do not intersect or are left between them.

  The adjustment of the axial position of the at least one return shaft gear for obtaining a desired set of tooth flanks offers, for example by using shaft nuts, the possibility of precisely adjusting the total clearance of the tooth. steering hub mechanism and, thus, reduce it to a minimum. When wear starts, for example on the bearings and / or the teeth, it is also possible to adjust the clearance by relatively simple provisions, for example by readjusting the single shaft nut or nuts shaft, or by inserting intermediate washers and in this way, at least to postpone the costly replacement of parts. However, this requires a visit to the workshop.

  An improvement of the second basic embodiment of the invention which is largely maintenance-free because it is automatic retrofit, therefore provides at least one return shaft spring by means of which at least one of pinions of the countershaft is biased with axial force towards its cone point.

  With a good design of the steering hub mechanism, it is furthermore possible that the two pinions of the countershaft can be loaded by the at least one return shaft spring with an axial force in the direction of their spindles. respective cone. For this, either the two countershaft gears must be mounted movable in axial translation and integral in rotation on the countershaft, or the mounting of the countershaft itself must be floating in the direction of its direction. axis, or at least one of the pinions of the countershaft must be mounted movable in translation on the countershaft.

  Another advantage of the alternative solutions presented for the problem posed must be considered in the fact that, according to an improvement, it can be provided in addition to an auxiliary force source which applies a torque to the return shaft. For this, it is sufficient to provide for the embodiments which comprise a translation of the axis of the return shaft, a corresponding compensation of the conjugate bearing necessary for the output of the torque in a motor.

  In embodiments that are based on a translation of at least one idler pinion gear on the countershaft, for example, the electric motor of a power steering can be directly coupled, for example to an end of the countershaft, while the motor housing is connected directly and rigidly, for example to the casing of the steering hub mechanism.

  However, in both variants, a particularly elegant solution is obtained because it saves space, when the additional auxiliary force source is disposed on the countershaft and between the gears of the countershaft, to which in the case of the use of a countershaft bearing bush, this bushing, with the countershaft bearings provided therein, may be part of the auxiliary force source or the motor.

  The invention will be explained in more detail with reference to the description of a preferred embodiment and to the accompanying drawings, in which FIG. 1 represents a steering shaft equipped with a steering hub mechanism according to the state of the art. ,

  FIG. 2 shows a steering shaft according to the invention with a steering hub mechanism comprising a return shaft according to the state of the art,

  FIG. 3 shows a first variant of a steering shaft according to the invention with a steering hub mechanism comprising a return shaft according to

  FIG. 4 shows a steering shaft according to the invention with a steering hub mechanism according to FIG. 3, but with an additional auxiliary force source, FIG. 5 represents a second embodiment of a steering shaft according to FIG. invention with a steering hub mechanism, and

  FIG. 6 illustrates a development of the steering shaft according to the invention comprising a steering hub mechanism according to FIG. 5. FIG. 1 illustrates a steering shaft comprising a steering hub mechanism 2 according to the state. of the technique, as described in a similar embodiment by the French patent FR 2,815,318 B1.

  A fixed steering hub 3 is integrally rotatably mounted on a hub axle 26 which has a cable channel 4 for receiving a cable 15 which leads to the fixed steering hub 3. A steering wheel rim 1 concentrically disposed at the hub fixed steering wheel 3 is mounted rotatably by means of a flywheel rim shaft 17 and a flywheel rim shaft bearing 18 and is integrally connected in rotation through at least one steering wheel rim 20, to a flywheel rim ring having an internal toothing 8, which is engaged with a gear wheel 11 of the steering mechanism shaft. The steering mechanism shaft 5 integrally connected in rotation to this toothed wheel 11 is connected by means of a screw mechanism 7 disposed outside the steering hub mechanism 2, to an auxiliary force shaft 6 which makes it possible to obtain auxiliary power assisted steering.

  As already mentioned at the beginning, in this kind of steering hub mechanism 2, there inevitably occurs a transformation of the rotational movement of the steering wheel rim 1 into a rotational movement of the steering mechanism shaft 5 in acceleration, which makes it seem at least problematic the use of identical steering mechanisms for vehicle variants with and without fixed steering hub, because the steering behavior of the vehicle is fundamentally changed.

  Furthermore, there is an axial offset between the center of the rim of the steering wheel 1 and that of the steering mechanism shaft 5, typically a few centimeters, and therefore an offset of the position of the steering wheel when passing to a vehicle, identical otherwise, but having a steering wheel without a fixed steering hub. The integration of an auxiliary power source 6 in the steering hub mechanism 2 is not provided.

  and, because of the volume of space as well as lack of suitable points for the introduction of a couple, this integration is hardly possible.

  On the contrary, Figure 2 illustrates a steering shaft of the kind in question and known per se comprising a steering mechanism shaft 2. In the following description, we will use the same references for the elements having the same function.

  The fixed steering hub 3 is also integrally connected in rotation to a hub axle 26, which, compared to the solution mentioned at the beginning, comprises a cable channel 4 which can be of much larger size, for the passage of a cable 15 leading to the fixed steering hub 3. A steering wheel rim 1 is again integrally connected in rotation to a flywheel rim shaft 17 by means of at least one flywheel rim radius 20, but in this case this shaft is rotatably mounted on the hub axle 26 through upper and lower flywheel shaft bearings, 18a, 18b. In replacement of an internally toothed rim ring, the flywheel rim shaft 17 has on the contrary an external toothing 10 which meshes with an intermediate shaft pinion 25a which is also toothed externally.

  The upper gear 25a of the countershaft is fixed, as well as a lower intermediate shaft pinion 25b, of the same construction in this case, on an intermediate shaft 9 which is rotatably mounted in the housing of the hub gear mechanism. direction 2 using the intermediate shaft bearings 23a and 23b.

  The lower gear 25b of the countershaft meshes with a pinion 11 of the steering mechanism shaft which is integrally fixed in rotation on a steering mechanism shaft 5 and is rotatably mounted by means of the mechanism shaft bearings. steering 19a and 19b.

  A steering shaft according to the invention comprising a steering hub mechanism 2 according to a first variant embodiment is shown in FIG. 3. Unlike the embodiment described above, the countershaft 9 is rotatably mounted by the bearings 23a, 23b of the countershaft, not directly in the casing of the steering hub mechanism 2 but, on the contrary, in a bushing 12 of a return shaft bearing which is secured jointly in rotation, but with a degree of freedom of translation, in the casing of the steering hub mechanism 2.

  For example, the bushing, including the countershaft 9 which is rotatably mounted in this bushing, can be moved in translation, by means of elongated holes provided in the plane of the drawing, of one or more millimeters to the right in the direction of the flywheel rim shaft 17, or in the direction of the steering mechanism shaft 5. An elastic mounting 13 of the return shaft bearing sleeve 11 is arranged, in the simplest case, by means of of a tension spring shown in the drawing, so that the deflection pinions 25a and 25b are pressed with a defined force against the outer toothing 10 of the flywheel rim shaft 17, respectively against the gear wheel steering mechanism shaft 11.

  In this way, any set of tooth flanks is largely eliminated and the total clearance of the steering hub mechanism 2 is effectively reduced. As a replacement for the helical tension spring shown, any other suitable spring, or a combination of several springs, may be used. Here, the pressure spring Belleville rubber or washer Belleville are particularly suitable, but hydraulic pushers with elasticity of spring, for example through the technique of the production of pressure of the hydraulic oil or accumulator pneumatic bubbles, too.

  Figure 4 shows the same steering shaft according to the invention as in Figure 3, with a steering hub mechanism 2 according to the first embodiment but with an additional auxiliary force source. This source is constituted by an electric motor and is directly connected kinematically to the countershaft 9. The casing of the auxiliary force source 6 is fixed integrally in rotation, for example in elongate holes, to the casing of the hub mechanism direction 2, so that a possible translation of the axis of the countershaft can occur without significant resistance.

  FIG. 5 represents a steering shaft according to the invention comprising a steering hub mechanism 2 according to a second variant embodiment. The countershaft pinions 25a and 25b are conical here, unlike the arrangement shown in FIG. 2. As a result, the corresponding toothing, the external toothing 10 of the flywheel rim shaft 17 and the wheel teeth of the steering mechanism shaft 11 are also conical.

  Between the pinions 25a, 25b of the countershaft, is disposed at least one element with which the axial position of at least one of the pinions 25a, 25b of the countershaft can be set on the countershaft 9 in such a way that the set of tooth flanks of the cooperating teeth 25a, 10 and 25b, 11 can be adjusted. If the countershaft 9 is not immobilized axially in the countershaft bearings 23a, 23b or with respect to the casing of the steering hub mechanism 2, it is already sufficient to provide for this a shaft nut. which can move one of the countershaft pinions 25a, 25b towards the end nearest to the countershaft 9. According to another variant, adjusting washers are used. If, on the contrary, the countershaft is locked axially relative to the casing of the steering hub mechanism 2, it is necessary to provide for each deflection gear 25a, 25b, at least one element allowing the adjustment axial.

  FIG. 6 shows another improvement of the steering shaft according to the invention comprising a steering hub mechanism 2 according to FIG. 5.

  As an element for adjusting the axial position of the pinions 25a and 25b of the countershaft, or their mutual spacing, use is made here of a return shaft spring 24 disposed on the countershaft 9 and constituted by a spring helical compression, which exerts a defined axial force on the gears 25a, 25b of the countershaft, so that these pinions 25a, 25b of the countershaft tend to move away from each other.

  This arrangement reduces the backlash, both on the upper gear 25a of the countershaft and on the lower gear 25b of the countershaft and it also has the effect that in case of possible wear of the sidewalls With teeth or bearings, the countershaft is self-adjusting and the manufacturing and assembly tolerances are automatically compensated.

  The present invention is not limited to the preferred embodiments described, but may be subject to various modifications or variations obvious to those skilled in the art.

List of references

  1 Steering wheel rim 2 Steering hub mechanism 3 Fixed steering hub 4 Cable channel 5 Steering shaft 6 Auxiliary power source 7 Screw mechanism 8 Steering ring ring with internal toothing 9 Idler shaft 10 External toothing of the flywheel rim shaft 11 Gear wheel of the steering gear shaft 12 Gear shaft bearing sleeve 13 Elastic mounting of the idler shaft bearing sleeve 12 not used 15 Cable leading to the hub stationary steering wheel 16 not used 17 Steering wheel rim shaft 18 Flywheel shaft bearing (18a upper bearing, 18b lower bearing) 19 Steering shaft bearing (19a upper bearing, 19b lower bearing) 20 Radius wheel rim 21 not used 22 not used 23 Idler shaft bearing (23a upper bearing, 23b lower bearing) 24 Idler shaft spring 25 Idler shaft pinion (25a top pinion, 25b lower pinion) 30 26 Axis d u hub 17

Claims (10)

  A steering shaft for a steering wheel comprising a fixed steering hub (3) and a steering hub mechanism (2) having a deflection shaft (9), in which the fixed steering hub (3) is arranged integrally rotated on a hub axle (26) provided with a cable channel (4), and which has a flywheel rim (1) substantially concentric with the axis of rotation of the hub axle (26) and movable in rotation, and which is integrally connected in rotation to a flywheel rim shaft (17) which receives the hub axle (26), and is constituted by a hollow shaft and which has, at its end remote from the rim flywheel (1) an outer toothing which is engaged with a first idler gear (25a) which is mounted together with a second idler gear (25b) on a idler shaft (9) and is secured to the first one in rotation, the second return shaft gear (25b) being engaged with a gear shaft gear Steering anism (11) which is integrally rotatably arranged on a steering mechanism shaft (5), characterized in that the deflection shaft (9) and / or the idler shaft (25a, 25b) disposed on the countershaft (9), and / or their bearings, comprise means (25a, 25, 12, 13, 24) arranged to reduce the clearance of the steering hub mechanism (2), or that such means (25a, 25b, 12, 13, 24) are arranged to act on them.   Steering shaft according to Claim 1, characterized in that the deflection shaft (9) is mounted floating with a degree of freedom in translation in at least one return shaft bearing (23), said deflection shaft (9) being prestressed in the direction of the flywheel rim shaft (17) and / or in the direction of the steering mechanism shaft (5) by at least one elastic element (13).   3. Steering shaft according to claim 2, characterized in that it comprises a shaft sleeve (12) in which said deflection shaft (9) is rotatably mounted by means of a bearing of a shaft of an upper deflection (23a) and a lower countershaft bearing (23b), and in that the bearing bush 18 of the countershaft (12) is mounted floating with a degree of freedom in translation in the direction of the flywheel rim shaft (17) and / or in the direction of the steering mechanism shaft (5), and preloading towards the flywheel rim shaft (17) and / or towards the steering wheel shaft (17); steering gear shaft (5) by at least one resilient mounting (13) of the countershaft bearing bush (12).   Steering shaft according to Claim 1, characterized in that at least one of the countershaft gears (25a, 25b) is tapered, in that the toothing of the flywheel rim shaft (10) is toothed externally, respectively, the toothed wheel of the steering mechanism shaft (11) which is engaged with the corresponding countershaft gear (25a, 25b), is of corresponding configuration, and in that the spacing of the gear wheels deflection shaft (25a, 25b) can be adjusted by adjusting the axial position of at least one deflection gear (25a, 25b) on the countershaft (9).   5. Steering shaft according to claim 4, characterized in that the at least two conical teeth (25a, 25b, 10, 11) engaged with each other have a convex shape, attached to their axis.   6. Steering shaft according to claim 4 or 5, characterized in that the at least two conical teeth (25a, 25b, 10, 11) engaged with each other have a hypoid toothing or a beveloid toothing. 25   Steering shaft according to at least one of Claims 4 to 6, characterized in that it comprises at least one return shaft spring (24) through which at least one of the return shaft gears (25a , 25b) is biased with axial force towards its cone tip. 30   Steering shaft according to Claim 7, characterized in that the two return shaft gears (25a, 25b) are axially biased towards their respective cone points by the at least one shaft spring. referral (24).   9. Steering shaft according to claim 1, characterized in that in addition, it comprises an auxiliary force source (6) which can apply a torque to the return shaft (9).   Steering shaft according to Claim 9, characterized in that the additional auxiliary force source (6) is arranged on the countershaft (9) and between the countershaft gears (25a, 25b).