PROGRESSIVE STEERING MECHANISM, TOOTHED COMPONENT AND MANUFACTURING METHODS

Abstract

A toothed component (10) for use in a progressive steering mechanism comprising a first and a second inclined pin ramp (14, 16). The first and second inclined pin ramps (14, 16) comprise a plurality of pins (20, 50), each having a first flank angle and a second flank angle with respect to a central plane (48) extending normal to a longitudinal direction (34) of the toothed component (10). For at least 50% of the pins (20, 50) of the plurality of pins (20, 50), the first flank angles have a unique first angle value and the second flank angles have a unique second angle value, the first angle value corresponding to a reflection of the second angle value in the central plane (48). The invention further comprises a progressive steering mechanism, a method for manufacturing a toothed component, and a method for manufacturing a steering mechanism. (Figure 1)

Description

PROGRESSIVE STEERING MECHANISM, TOOTHED COMPONENT AND MANUFACTURING METHODS TECHNICAL FIELD OF THE INVENTION The invention relates in general to the technical field of vehicle steering systems and in particular to the field of progressive steering systems and / or rack and pinion steering systems. BACKGROUND OF THE INVENTION Progressive steering systems are well known in a wide variety of configurations. For example, patent document WO 2006 / 079492 A1 shows several embodiments of a progressive steering mechanism. According to one embodiment, which has proven to be particularly advantageous in practice, a progressive steering mechanism has three inclined racks located in different planes and three associated spur gears. In steering positions on one side of the center position, the center spur gear meshes with the center rack, while in steering positions on the other side of the center position, the two outer spur gears mesh with the two outer racks. Implementation in accordance with WO 2006 / 079492 A1, as briefly described above, has already proven highly advantageous in practice. However, in the course of extensive work and testing, further improvements have been identified, particularly with regard to, but not limited to, a particularly harmonious driving experience and / or cost-effective manufacturing. These improvements are the subject of the present invention. BRIEF DESCRIPTION OF THE INVENTION The invention is defined by the independent claims. The dependent claims relate to optional features of some embodiments of the invention. A first aspect of the invention relates to a toothed component for use in a progressive steering mechanism, comprising a first and a second inclined ramp of pins having a plurality of pins, each of which has a first flank angle and a second flank angle with respect to a central plane running normal to a longitudinal direction of the toothed component. For at least 50% of the pins, the first flank angles have a 7PQP7n / C7n7 / 3 / YILI first unique angle value, and the second flank angles have a second unique angle value, the first angle value corresponds to a reflection of the second angle value in the central plane. It was discovered that using pins according to the invention, instead of the teeth commonly used in rack and pinion steering systems, offers considerable advantages. The uniform flank angles, which are symmetrical with respect to the central plane, result in a particularly smooth and safe steering experience and / or allow for relatively inexpensive manufacturing. These results are surprising because they contradict calculations and optimizations of tooth geometries carried out over many decades, particularly in the field of rack and pinion steering systems. Other aspects of the invention relate to a progressive steering mechanism, a method of manufacturing a toothed component, and a method of manufacturing a steering mechanism. BRIEF DESCRIPTION OF THE FIGURES Other features, advantages, and objects of the invention will be evident from the accompanying schematic drawings of multiple embodiments by way of example, in the drawings: Figure 1 shows a side view of a toothed component and a pinion component according to a first embodiment as an example of the invention. Figure 2 shows a perspective view of the components of a progressive steering mechanism according to a second exemplary embodiment of the invention, which differs only slightly from the first exemplary embodiment shown in Figure 1. Figure 3 shows an enlarged view of the geometry of the spikes in the first and second embodiments as an example. Figure 4 shows a side view similar to Figure 1 in a third embodiment as an example with steeper flank angles of the spikes. Figure 5 shows a side view similar to Figure 1 in a fourth embodiment as an example in which the toothed component does not have a central pin. Figure 6 shows an orderly exploded view of a pinion component and associated components in an additional example embodiment. Figure 7 shows a schematic diagram illustrating the design of a pinion element. 7PQP7n / C7n7 / 3 / YILI Figure 8 and Figure 9A each show an enlarged side view to illustrate the rolling behavior in the first and second embodiments as examples, respectively. Figure 9B shows an enlarged side view similar to Figure 9A in a comparative example. Figure 10A shows a schematic side view of the first and second embodiments as an example of the invention. Figure 10B shows a schematic side view of a zipper in a comparative example, where the scale is similar to that in Figure 10A. Figure 11 shows a perspective view of a steering mechanism according to another embodiment as an example of the invention. Figure 12 shows a perspective view as in Figure 11, in which only the toothed component and the pinion component are shown. DETAILED DESCRIPTION OF THE INVENTION A progressive steering mechanism according to the embodiments shown as examples in the drawings comprises a toothed component 10 and a pinion component 12. The toothed component 10 includes a first, a second, and a third pin ramp 14, 16, 18, which are arranged in three planes arranged one behind the other in the side-viewing direction of the component 10 according to Figure 1. The first pin ramp 14 is visible on the left in Figure 1. The second pin ramp 16 is visible mainly on the right in Figure 1, namely, except for a central pin 20 (Figure 2) on which the first and second pin ramps 14, 16 overlap.The third spike ramp 18 is partially visible in Figure 2, but in Figure 1 it is completely hidden by the first spike ramp 14, which, in the side view of Figure 1, has contours identical to the third spike ramp 18 and is located exactly opposite it. Although the example embodiments shown in Figure 1 and Figure 2 include a central tenon 20 common to the three tenon ramps 14, 16, 18, embodiments are also contemplated in which the second tenon ramp 16 does not overlap with the first and third tenon ramps 14, 18, as well as embodiments in which the overlap extends over several central tenons, for example, two or three tenons. In the present embodiment, by way of example, the spike ramps 14, 16, 18 7PQP7n / C7n7 / 3 / YILI are integrally formed with a base 22 having side portions 24 and a lower support portion 26. The support portion 26 may have, for example, a rectangular or dovetail cross-section. In the exemplary embodiment shown in Figure 2, the support portion 26 is guided and pressed against the pinion component 12 by a spring-loaded pressure element 28. For example, the pressure element 28 may provide a spring travel of at least 0.1 mm or at least 0.2 mm. The steering mechanism is designed such that the toothed component 10 is adapted to move along this spring travel relative to the pinion component 12. On both sides, the toothed component 10 has respective connecting means—for example, a screw thread each—for connecting to a respective joint element of a steering tie rod.Figure 2 shows an example of such a joint element 30. In some embodiments, no additional guidance is provided for the toothed component 10—other than that provided by the steering tie rods, the pressure element 28, and the pinion component 12—within a steering mechanism housing (not shown in the figures). However, in other exemplary embodiments, the side portions 24 also serve to guide the toothed component 10 within the steering mechanism housing. Such steering mechanisms with a toothed component 10 guided by the side portions 24 are particularly stable. In the exemplary embodiments described in the present invention, a lower side of the support portion 26—and thus the base 22—forms a flat base plane 32 that extends parallel to a longitudinal direction 34 of the toothed component 10. Therefore, both the longitudinal direction 34 and the base plane 32 extend in the direction in which the toothed component 10 moves back and forth during steering movements. Corresponding to the toothed component 10 with its spline ramps 14, 16, 18 arranged in three planes, the pinion component 12 has a first, a second, and a third pinion element 36, 38, 40 situated in the same three planes. The three pinion elements 36, 38, 40 are rigidly arranged relative to each other and rotatably fixed to a steering shaft end member 42, which is in turn supported in a steering shaft bearing 44. The steering shaft end member 42 together with the pinion component 12 located above it is knownly coupled to a steering wheel (not shown) through various sections of a steering shaft and / or steering column (not shown), such that steering movements 7PQP7n / C7n7 / 3 / YILI cause a corresponding rotation of the pinion component 12. In this case, both the steering shaft end member 42 and the three pinion elements 36, 38, 40 rotate around a common rotation axis 46. In the exemplary embodiments described in the present invention, the first pinion element 36 has an identical outline to the third pinion element 40 in the side view of Figure 1, such that the first pinion element 36 exactly covers the third pinion element 40. The second pinion element 38 is approximately or exactly mirror-symmetric with respect to the first and third pinion elements 36 and 40. Furthermore, in the exemplary embodiments described in the present invention, the first pinion element 36 has the same thickness as the third pinion element 40 but only half the thickness of the second pinion element 38. Consequently, the first pin ramp 14 has the same thickness as the third pin ramp 18 but only half the thickness of the second pin ramp 16. The first pinion element 36 is adapted to mesh with the first pin ramp 14 in steering positions where the steering wheel is turned clockwise from the center position from the driver's perspective, as is the case, for example, in Figure 2. When the steering wheel is turned counterclockwise, the toothed component 10 moves to the left in the orientation shown in Figure 2 until the first toothed element 26 disengages from the first pin ramp 14 and rotates freely in the empty space to the right of the first pin ramp 14.This displacement of the toothed component 10 in its longitudinal direction 34 is converted into a corresponding steering movement of the vehicle's wheels; the direction of the steering movement (i.e., whether the vehicle's wheels rotate to the right or to the left in the direction of travel) depends on the installation position of the steering mechanism. The third pinion element 40 and the third pin ramp 18 behave in the same way as the first pinion element 36 and the first pin ramp 14. The second pinion element 38, on the other hand, rotates freely in the position shown in Figure 2 and, when the balance wheel is turned counterclockwise from this position, engages with the second pin ramp 16 from approximately the middle position of the balance wheel, i.e., first with the central pin 20 and then with the pins shown further to the right in Figure 2. Each of the spike ramps 14, 16, 18 is inclined, namely, the second 7PQP7n / C7n7 / 3 / YILI peg ramp 16 in the opposite orientation to the first and third peg ramps 14, 18. A central plane 48 is arranged normal to the base plane 32 and the longitudinal direction 34. In the embodiments described herein, the central plane 48 forms a plane of symmetry with respect to the general inclination of the peg ramps 14, 16, 18. In some embodiments, the central plane 48 represents an exact plane of symmetry. However, embodiments are also contemplated in which the peg ramps 14, 16, 18 are not completely symmetrical to each other and, therefore, the central plane 48 is only approximately a plane of symmetry. In some embodiments, a central peg 20 is provided, and the central plane 48 extends through a tip of this central peg 20.Furthermore, in some embodiments, the central plane 48 extends through the rotation axis 46 of the pinion component 12 when the steering mechanism is in a central position. In addition to the central tenon 20, each of the three tenon ramps 14, 16, 18 comprises a plurality of additional tenons, some of which are indicated by the reference sign 50 in the figures of the drawings. For example, in addition to the central tenon 20, each of the three tenon ramps 14, 16, 18 may include approximately ten additional tenons 50, more generally between seven and thirteen additional tenons 50. Each tenon 20, 50 has, as shown in Figure 3, an approximately straight first flank 52 and an approximately straight second flank 54 between which a rounded tip 56 is formed. A rounded valley 58 is formed respectively between a first flank 52 of a first tenon 20, 50 and an adjacent second flank 54 of an adjacent second tenon 20, 50. A tenon base 60, 62 extends respectively between two valleys 58 of a tenon 20, 50.In the case of the central tenon 20, the first and second straight flanks 52, 54 have the same length, and the tenon base 60 extends horizontally, i.e., parallel to the base plane 32 and the longitudinal direction 34. In the case of tenons 50 that differ from the central tenon 20, the first and second straight flanks 52, 54 are of different lengths, depending on the inclination of the tenon base 62 with respect to the base plane 32 and the longitudinal direction 34. For example, a slope plane 64 averaged over the longitudinal extent of a dowel ramp 14, 16, 18, as exemplified in Figure 1 for dowel ramp 16, may have an angle of approximately 15° relative to the base plane 32 and the longitudinal direction 34, or more generally an angle between 8° and 25°, or an angle between 10° and 20°. The angle of the slope plane 64 corresponds to the average angle of the associated dowel bases 62. However, variations may exist. 7PQP7n / C7n7 / 3 / YILI local because in many embodiments the pin ramps 14, 16, 18 are not inclined in a straight line, but include local corrections. These corrections can serve, for example, to compensate for a rolling mechanism progression and / or a cardan joint error. Each first flank 52 of a tenon 20, 50 forms a first flank angle with respect to the central plane 48, and each second flank 54 forms a second flank angle with respect to the central plane 48. An important feature of the tenons 20, 50 provided according to the invention is that, at least for a significant portion of the total number of tenons 20, 50, all first flank angles have a unique first angle value +a, and all second flank angles have a unique second angle value -a corresponding to a reflection of the first angle value +a in the central plane 48. For example, in the exemplary embodiment shown in Figure 1, for each tenon 20, 50 shown, the first angle value is +33°, and the second angle value is correspondingly -33°, each with a permissible deviation of +10% or ±5% or ±2%. The property that the first and second flank angles have angular values ​​of +a and -a, respectively, applies in several embodiments to at least 50% of the tenons 20, 50, or at least 70% of the tenons 20, 50, or at least 80% of the tenons 20, 50, or at least 90% of the tenons 20, 50, or to all of the tenons 20, 50. Furthermore, embodiments are conceived in which these percentages refer only to those tenons 50 that have a respective tenon base 62 inclined with respect to the base plane 32 and the longitudinal direction 34. In other words, in these embodiments, the central tenon 20 and any other tenon having a tenon base parallel to the base plane 32 are not taken into account in the calculation of the percentages. The first and second angle values ​​can be selected differently in different embodiments, but with the same absolute amounts for each embodiment. For example, Figure 4 shows an example embodiment with steeper tenon flanks 52, 54, in which the first angle value is +25° for each tenon 20, 50 shown, and the second angle value is -25°, in each case with a permissible deviation of ±10% or ±5% or ±2%. This embodiment has the advantage that a larger radius of curvature can be selected for the tips 56 and the valleys 58 of the tenons 20, 50. It is understood that in other embodiments other values ​​of the first and second angle values ​​are possible, for example, ±25°± 5% or +30°±10% or ±30°±5% or ±33°±5% or ±35°±10% or ±35°±5%. Pinion elements 36, 38, and 40 also have pins, some of which The pins 7PQP7n / C7n7 / 3 / YILI are indicated by the reference symbol 70 in the drawings. The pins 70 are arranged and shaped so that they mesh with the pins 20, 50 of the pin ramps 14, 16, 18 and provide a harmonic rocking motion. For example, the pins 70 may have flanks curved in the direction of an involute or cycloid tooth pattern. This results in a first rolling curve 72 on the first pin ramp 14 shown on the left in Figure 1, a second rolling curve 74 on the second pin ramp 16 shown on the right in Figure 1, and the corresponding third and fourth rolling curves 76, 78 on the first and second pinion elements 36, 38, respectively.On average over the length of the first and second spike ramps 14, 16, the course of the first and second rolling curves 72, 74 respectively follows the slope of the corresponding spike ramp 14, 16, as illustrated, for example, by the slope plane 64. In the embodiments described in the present invention, the pressure element 28 is spring-loaded and provides a relatively large spring travel of, for example, 0.1 mm or 0.2 mm. Therefore, there is considerable room for manufacturing tolerances and / or deliberate deviations to optimize steering behavior. As already mentioned, embodiments are also conceived in which the toothed component 10 has no central pin 20. Figure 5 shows a corresponding example embodiment. In this case, the first and second pin ramps 14, 16 terminate to the left and right of the central plane 48, respectively, with a pin 50 that does not represent a central pin 20 because it has an inclined pin base 62. In contrast, the pinion component 12 has a central pin 80 that is formed from the three pinion elements 36, 38, 40 and which, in the central position of the steering mechanism, as shown in Figure 5, extends symmetrically with respect to the central plane 48 and fits between the two pins 50 mentioned above to the left and right of the central plane 48. In the example embodiment shown in Figure 5, the tenon 50 adjacent to the left of the central plane 48 is formed only on the first tenon ramp 14 (as well as on the third tenon ramp 18, which is not visible in Figure 5). Consequently, the tenon 50 adjacent to the right of the central plane 48 is formed only on the second tenon ramp 16. However, embodiments are also contemplated in which the two aforementioned tenons 50 are formed via the three tenon ramps 14, 16, and 18, such that the tenon ramps 14, 16, and 18 overlap in the region of these two tenons 50. The exploded view of pinion component 12 in Figure 6 illustrates the use of a steering shaft end member 42 with a non-circular cross-section onto which the three pinion elements 36, 38, and 40 are pressed and thus held in the desired angular position relative to each other. A bearing, namely the steering shaft bearing 44 and an additional bearing 82, is provided on either side of the assembly formed by the three pinion elements 36, 38, and 40. Spacers 84 provide a desired distance between the pinion elements 36, 38, and 40 to ensure a desired clearance between the pinion elements 36, 38, and 40 and the pin ramps 14, 16, and 18, and, for example, to prevent the second pinion element 38 from rubbing laterally against one of the two pin ramps 14 and 18.In the example embodiment shown in Figure 6, the spacers 84 are formed as projections or grease fittings on the pinion elements 36, 38, 40 and the bearings 44, 82. However, embodiments are also conceived in which wedges or other separate components, similar to washers, serve as spacers 84. Figure 7 illustrates an example of the design of a pinion element, for example, the first pinion element 36. Each pin 70 has a pin base 86 whose inclination corresponds approximately to the inclination of the rolling curve 76 (Figure 1) on the respective pin 70. A respective normal 88 to each pin base 86 does not pass through the axis of rotation 46, but passes laterally from it. The steering mechanism described in the present invention has a progressive gear ratio feature. In a central position of the steering mechanism, the steering allows for sensitive steering movements because the distance between the rotation axis 46 of the pinion component 12 and the pitch point between the rolling curves 72, 74, 76, 78 is small. As the steering deflection increases, the distance between the rotation axis 46 and the pitch point becomes progressively larger, so that relatively small movements of the steering wheel lead to relatively large shift displacements of the toothed component 10. This is particularly useful for maneuvering and parking operations. In some embodiments, the rolling curves 72, 74 of the toothed component 10 are conceived as straight (but inclined), and the rolling curves 76, 78 of the pinion component 12 are spiral. The steering mechanism's transmission ratio then changes in proportion to the angle by which the pinion component 12 rotates about its central position (Figure 1). In practical tests, however, it has been found that it can be advantageous to account for deviations caused, for example, by the cardan error of a universal joint in the steering shaft and / or by the rolling mechanism progression of a vehicle. Therefore, embodiments are also contemplated, as shown, for example, in the figures in the drawings, in which such deviations are corrected by non-straight rolling curves 72, 74 of the toothed component 10.Depending on the nature of the deviations to be corrected, the non-rectilinear rolling curves 72, 74 can be mirror-symmetric or asymmetric to each other. The rolling curves 76, 78 of pinion component 12 are adapted accordingly. The geometry of the toothed component 10 described in the present invention differs in particular from the embodiments known to WO 2006 / 079492 A1 in that, at least for most of the pins 20, 50, an angle bisector 90 of the respective pin 20, 50 runs parallel to the central plane 48, i.e., perpendicular to the longitudinal direction 34 and / or the base plane 32. This applies at least to most of the pins 50 whose pin base 62 is inclined with respect to the longitudinal direction 34 and / or the base plane 32. In contrast, in the embodiments known to WO 2006 / 079492 A1, the angle bisectors of all the teeth are perpendicular to the respective tangents of the rolling curve on the respective tooth. The design according to the invention allows for a particularly harmonious and safe driving and steering experience. This is due in particular to the fact that counterforces caused, for example, by the restoring forces of the rolling mechanism or by road influences, which can occur in both directions, are fed back evenly to the steering wheel. This is illustrated for the center steering position in Figure 8 and for a turned position in Figure 9A. Figure 9B shows the turned position as in Figure 9A for a comparative example having a known tooth shape of a pinion and rack, in which for each tooth an angle bisector of the tooth flanks is aligned normal to the tooth base.In the comparative example shown in Figure 9B, the counterforces are fed back to the steering wheel unevenly depending on the direction of the counterforce, as shown by the horizontal arrows in Figure 9B. In contrast, according to Figure 8 and Figure 9A, the forces shown by the horizontal arrows, which are coupled to the steering wheel, are independent of the direction in which these forces act. The same applies to the portion of the counterforces that are coupled to pressure element 28, as shown by the vertical arrows in Figures 8, 9A, and 9B. Since pressure element 28 is spring-loaded and provides a 7PQP7n / C7n7 / 3 / YILI with a relatively large spring travel of, for example, 0.2 mm, each force coupled to the pressure element 28 changes the direction of travel. Therefore, it is advantageous that the proportion of forces applied to the pressure element 28 is independent of whether these forces push the toothed component 10 to the right or to the left. In general, thanks to the uniform lateral load, disruptive fluctuations between a steering force and a counterforce (e.g., restoring force) are balanced. This results in a more harmonious and confident steering and driving experience with particularly good steering response. An additional advantage in some embodiments of the invention is that the tenon geometry described herein provides a central tenon 20 that is at least normally strong or even reinforced. This is shown in Figure 10A, where the tenon base 60 of the central tenon 20 is at least as long as the tenon base 62 of a side tenon 50 and, in the example embodiment of Figure 10A, even slightly longer. This increases the stability of the central tenon 20 under heavy stress and thus represents a considerable additional advantage of the embodiments described herein. Figure 10B shows a comparative example with a known zipper tooth shape, in which a tooth base 94 of a center tooth 92 is significantly shorter than a tooth base 98 of a side tooth 96. Thus, in this comparative example, the center tooth 92 is significantly weaker than the side teeth 96. Figures 11 and 12 show another exemplary embodiment of a steering mechanism in which two changes have been made compared to the exemplary embodiments described above. These two changes are, first, that the steering mechanism has a motor 100 with a motor shaft connected to the pinion component 12 in a rotatably fixed manner or by means of a gear, and second, that pins 50A, 50B, 50C, 70A, 70B, and 70C of different sizes are provided on the toothed component 10 and the pinion component 12. The two modifications mentioned above work advantageously together, but each can also be used independently. Therefore, the disclosure content of this document also includes embodiments such as those described so far (Figures 1-12), which are modified in such a way that they comprise only the 100 motor, or only the 50A, 50B, 50C, 70A, 70B, 70C pins of different sizes, or both. Figure 10A already shows an embodiment in which the central tenon 20 has a tenon base 60 longer than the tenon base 62 of the other tenons 50. In the toothed component 10 according to Figure 11 and Figure 12, however, the tenons 50A, 50B, and 50C are also dimensioned differently; that is, for example, they have tenon bases of different lengths and / or have different tenon heights. In the embodiment according to Figure 11 and Figure 12, the tenons 50A adjacent to the central tenons 20 on both sides are the largest, and the tenons 50C at both ends of the toothed component 10 are the smallest. The size of the intermediate tenons 50B decreases uniformly or in a stepped manner as the distance from the central plane 48 increases. However, in other embodiments, the size progression of the 50A, 50B, 50C pins is the opposite of that shown in Figure 11 and Figure 12, so that the 50A pins (and one or more central pins 20, if any) are the smallest, the 50C pins are largest at the ends of the toothed component 10, and the intermediate 50B pins increase in size uniformly or in a staggered fashion as the distance from the central plane 48 increases. Other size gradients are also provided in additional embodiments. This includes, among others, size gradients in which the intermediate ears 50B are larger than the near-center ears 50A and the outer ears 50C, and size gradients in which the intermediate ears 50B are smaller than the two near-center ears 50A and the outer ears 50C. Except for their different sizes, the center pins 20 and pins 50A, 50B, and 50C have the characteristics of the exemplary embodiments described so far. In particular, also in the exemplary embodiment according to Figure 11 and Figure 12, the flank angles of all pins 50A, 50B, and 50C are equal or mirror images of the center plane 48. It is understood that, in all embodiments described in the present invention, one center pin 20 (as shown in Figure 1), two center pins 20 (as shown in Figure 11 and Figure 12), or no center pin common to the pin ramps 14, 16, and 18 (as shown in Figure 5) may optionally be provided. Each of the pins 70A, 70B, 70C of the pinion elements 36, 38, 40 has the corresponding shape to the pins 50A, 50B, 50C of the pin ramps 14, 16, 18 and, therefore, are also formed in different sizes. The motor 100 for the power steering, also shown in Figure 11, is designed, for example, as a gearless electric motor whose motor shaft is rotatably fixed to the pinion component 12. In the In the exemplary embodiment shown in Figure 11, the motor shaft is integrated into the steering shaft and forms a section of the steering shaft. A steering shaft fixing member 102 is shown in Figure 11. In other words, this section of the steering shaft carries a rotor assembly (coil and / or permanent magnet) of the motor 100. Due to the progressive action of the steering mechanism according to the invention, no reduction mechanism is provided in the exemplary embodiment shown in Figure 11. When the motor 100 is de-energized, it does not interfere with the steering movements or with the tactile feedback of the steering mechanism to the driver regarding road conditions. In alternative embodiments, the motor 100 may be connected to the steering shaft via a reduction mechanism. This may be, for example, a planetary gear set (epicyclic gear train), the central gear of which is formed by or permanently connected to the steering shaft, and whose ring gear is permanently connected to the rotor of the motor 100. Such a planetary gear set may, for example, have a reduction ratio of 1:5 to 1:20 (preferably approximately 1:10), so that when the motor 100 is de-energized, it does not, or only to a limited extent, impede feedback signals from the steering mechanism to the driver. In further alternative embodiments, a bevel gear or a spur gear train may be used instead of the planetary gear set. Designs such as those shown in Figure 11 and Figure 12, in which pins 50A, 50B, 50C, 70A, 70B, and 70C are of different sizes, allow for the transmission of larger torques at selected steering angles. These might be, for example, steering angles where higher steering forces are typically generated and / or steering angles where the 100 motor provides particularly high power steering assistance. Alternatively or additionally, in embodiments with 50A, 50B, 50C, 70A, 70B, 70C pins of different sizes, a tool used to manufacture the pin ramps 14, 16, 18 and / or the pinion elements 36, 38, 40 can be optimized and / or simplified. For example, in some embodiments, the number of 50A, 50B, 50C, 70A, 70B, 70C pins can be reduced while maintaining the same steering quality when forming pins of different sizes.A smaller number of pins 50A, 50B, 50C, 70A, 70B, 70C simplifies manufacturing and requires only a less elaborate tool. In some embodiments, the toothed component 10 can be manufactured by forging, impact extrusion, flow drawing, or sintering. In particular, when 7PQP7n / C7n7 / 3 / YILI are used forging or impact extrusion or flow drawing processes, the tenon geometry described in the present invention has the advantage of allowing a tool to be easily removed from the machined toothed component 10 due to the uniformity of the flank angles and their symmetrical orientation with respect to the central plane 48. This allows for more cost-effective manufacturing. In further embodiments, each toothed element 36, 38, 40 is manufactured by impact extrusion, flow drawing, or punching. The individual elements 36, 38, 40 are then pressed onto the steering shaft end member 42, as illustrated in Figure 6. In general, the invention is not limited to the use of the processes mentioned above, but all processes for the production of three-dimensional bodies, with or without mechanical finishing, can be used. This includes, but is not limited to, for example, 3D printing or precision casting. Due to the shape of the pins according to the invention, in some embodiments only a relatively low surface finish quality is required for pins 20, 50 of the toothed component 10 and / or pins 70, 80 of the pinion component 12. For example, it may be sufficient for these pins 20, 50, 70, 80 to have a roughness described as "scrupped" (Ra between 3.2 µm and 25 µm). In some embodiments, the roughness Ra can be up to 16 µm or approximately 16 µm. This relatively high roughness can make some manufacturing processes (e.g., 3D printing without finishing) less expensive or even possible in the first place. Furthermore, a relatively high roughness has the advantage that the lubricant adheres better to the flanks of pins 20, 50, 70, 80. The details provided in the preceding description and shown in the drawings should be regarded not as limitations on the scope of the invention, but as examples of some embodiments thereof. Other variations will be readily apparent to persons skilled in the art. In particular, the features of the embodiments described above may be combined to obtain further embodiments of the invention. Consequently, the scope of the invention is defined not by the exemplary embodiments described, but by the claims and their equivalents. LIST OF REFERENCE NUMBERS toothed component pinion component 15 14 first pin ramp 16 second pin ramp 18 third pin ramp 20 center pin (of the pin ramps) 22 base 24 side portion 26 support portion 28 pressure element 30 joint member 32 base plane 34 longitudinal direction 36 first pinion element 38 second pinion element 40 third pinion element 42 steering shaft end member 44 steering shaft bearing 46 pivot axis 48 center plane 50 pins (of the pin ramps) 50A, 50B, 50C pins (of the pin ramps) in Figure 11 and in Figure 12 52 first flank 54 second flank 56 tip 58 valley 60 pin base (of center pin 20) 62 pin base (of a pin 50) 64 inclination plane 70 pins (of the pinion elements) 70A, 70B,700 pins (of the pinion elements) in Figure 11 and in Figure 12 72 first rolling curve (of the first pin ramp) 74 second rolling curve (of the second pin ramp) 76 third rolling curve (of the first pinion element) 78 fourth rolling curve (of the second pinion element), 7PQP7n / C7n7 / 3 / YILI center pin (of the pinion elements in Figure 5) spacer bearing pin base (of the pins of the pinion elements) normal angle bisector center tooth (of the comparative example in Figure 10B) tooth base (of center tooth 92 in the comparative example in Figure 10B) tooth (of the comparative example in Figure 10B) tooth base (of tooth 96 in the comparative example of the Figure 10B) 100 motor 102 steering axle fixing member

Claims

1. A toothed component (10) for use in a progressive steering mechanism, having a first and a second inclined ramp of pins (14, 16) comprising a plurality of pins (20, 50) each having a first flank angle and a second flank angle with respect to a central plane (48) running normal to a longitudinal direction (34) of the toothed component (10), characterized in that: for at least 50% of the pins (20, 50) of the plurality of pins (20, 50), the first flank angles have a unique first angle value and the second flank angles have a unique second angle value, the first angle value corresponding to a reflection of the second angle value in the central plane (48).

2. The toothed component (10) according to claim 1, characterized in that, for at least 70% or at least 90% of the pins (20, 50) of the plurality of pins (20, 50), the first flank angles have the first angle value and the second flank angles have the second angle value.

3. The toothed component (10) according to claim 1, characterized in that, for at least 50% or at least 70% or at least 90% of said pins (50) of the plurality of pins (20, 50) having a base (62) inclined with respect to the longitudinal direction (34) of the toothed component (10), the first flank angles have the first angle value and the second flank angles have the second angle value.

4. The toothed component (10) according to any of claims 1 to 3, characterized in that the first angle value and the second angle value for the flank angles of each pin (20, 50) allow a deviation of ±20%.

5. The toothed component (10) according to any of claims 1 to 3, characterized in that the first and second angle values ​​are x ± 10%, where x is a value between 25° and 40°.

6. The toothed component (10) according to any of claims 1 to 5, characterized in that the first and second spike ramps (14, 16) are arranged with opposite inclinations.

7. The toothed component (10) according to any of claims 1 to 6, characterized in that the central plane (48) is perpendicular to a base surface (32) of the toothed component (10). 7PQP7n / C7n7 / 3 / YILI 8. The toothed component (10) according to any of claims 1 to 7, characterized in that the component (10) has a central pin (20) with a pin base (60) that is larger than a pin base (62) of each laterally adjacent pin (50).

9. The toothed component (10) according to any of claims 1 to 8, characterized in that the first spike ramp (14) is designed for a first rolling curve (72) and the second spike ramp (16) is designed for a second rolling curve (74), each of the rolling curves (72, 74) extends obliquely to the central plane (48) and deviates, in at least 50% of its extension, by a maximum of 10° from a straight rolling curve.

10. The toothed component (10) according to any of claims 1 to 8, characterized in that the first pin ramp (14) is designed for a first rolling curve (72) and the second pin ramp (16) is designed for a second rolling curve (74), each of the rolling curves (72, 74) extending in a straight line and obliquely to the central plane (48), except for deviations to correct a rolling mechanism progression and / or a cardan joint error.

11. The toothed component (10) according to any of claims 1 to 10, characterized in that the first spike ramp (14) is designed for a first rolling curve (72) and the second spike ramp (16) is designed for a second rolling curve (74), wherein each of the first and second rolling curves (72, 74) is not rectilinear, and wherein the first and second rolling curves (72, 74) are not mirror symmetric to each other.

12. The toothed component (10) according to any of claims 1 to 10, characterized in that the first pin ramp (14) is arranged, when viewed from a side view in a viewing direction, in a plane opposite a plane of the second pin ramp (16).

13. The toothed component (10) according to claim 12, characterized in that the toothed component comprises a third pin ramp (18) which, in side view, is substantially identical to the first pin ramp (14) and is arranged, in the viewing direction, in a plane behind the planes of the first and second pin ramps (14, 16).

14. The toothed component (10) according to any of claims 1 to 13, characterized in that at least some of the pins (50A, 50B, 50C) have different sizes. 7PQP7n / C7n7 / 3 / YILI 15. A progressive steering mechanism comprising a toothed component (10) according to any of claims 1 to 14 and a pinion component (12) comprising a plurality of pinion elements (36, 38), each of which is associated with a respective pinion ramp (14, 16) and is arranged to engage or disengage from the associated pinion ramp (14, 16) depending on a respective steering angle.

16. The steering mechanism according to claim 15, characterized in that the toothed component (10) is adapted to be substantially displaced in the longitudinal direction (34).

17. The steering mechanism according to claim 15 or claim 16, characterized in that the toothed component (10) is pressed against the pinion component (12) under a spring load and is movable in the direction of the central plane (48) by at least 0.1 mm with respect to the pinion component (12).

18. The steering mechanism according to any of claims 15 to 17, characterized in that each pinion element (36, 38) has a plurality of pins (70), each having a pin base (86), wherein the respective normals (88) of the plurality of pins (70) pass through the axis of rotation (46).

19. The steering mechanism according to any of claims 15 to 18, characterized in that the steering mechanism further comprises a motor (100) having a motor shaft that is connected to the pinion component (12) in a rotationally fixed manner or through a planetary gear.

20. A method of manufacturing a toothed component (10) according to any of claims 1 to 14, characterized in that the toothed component (10) is manufactured by forging or impact extrusion or flow drawing or sintering.

21. A method of manufacturing a steering mechanism according to any of claims 15 to 19, characterized in that the toothed component (10) is manufactured by forging or impact extrusion or flow drawing or sintering, and / or in that each pinion element (36, 38, 40) is manufactured by impact extrusion or flow drawing or punching.

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