BE1030684B1 - Universal joint for a universal joint of a steering column for a motor vehicle, universal joint and steering shaft for a motor vehicle - Google Patents

Abstract

The present invention relates to a universal joint (4) for a universal joint (3), comprising two pairs of pins (41), which have pin axes (A, B) crossed at right angles to one another in a cross plane (AB), and each of which has a coaxial to Have a cylindrical lateral surface (42) formed on the pin axis (A, B) and an axial end face (43), the lateral surface (42) and the end face (43) being connected via an edge section (44) running in the circumferential direction. In order to enable improved assembly with a compact and lightweight design, the invention proposes that at least one partial recess (5) is formed in the edge section (44).

Description

'BE2022/5530

Universal joint for a universal joint of a steering column for a motor vehicle, universal joint and

Steering shaft for a motor vehicle

State of the art

The invention relates to a universal joint for a universal joint, comprising two pairs of pins, which have pin axes crossed at right angles to one another in a cross plane, and which each have a cylindrical lateral surface formed coaxially to the pin axis and an axial end face, the lateral surface and the end face having one in the circumferential direction circumferential edge section are connected, at least one partial recess being formed in the edge section. A universal joint with such a universal joint and a steering shaft for a motor vehicle comprising such a universal joint are also the subject of the invention.

In a motor vehicle, the steering shaft is used to transmit the input into the steering wheel

Steering torque from the steering spindle and the intermediate shaft to the steering gear. To compensate for

At least one, usually two universal joints are integrated in the course of the steering shaft, usually between the steering spindle and the intermediate shaft and between the intermediate shaft and the steering gear.

In the basic structure, each universal joint has two joint forks attached to one shaft end, each of which has two arms which extend axially in the direction of the shaft and lie opposite one another transversely to the shaft axis and which form a yoke. An articulated cross has two

Pairs of oppositely radially projecting joint pins, referred to as pins for short, which are arranged on pin axes crossed at right angles and lying in a cross plane.

The two pins of a pair are each mounted in an arm of a joint fork in a bore, which is also referred to as a pin armhole, in a pin bearing so that they can rotate about their pin axis.

In order to enable safe and resilient storage, the length of the pair of pins is:

Tenon pair length, measured in the direction of the tenon axis over the two outer free end faces of the tenons, greater than the distance between the arms, the arm distance, which is measured between the opposite insides of the arms. As a result, each of the pins can be supported radially in the bore with a bearing length corresponding to half the difference between the arm distance and the pin pair length.

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For assembly, the pin axis is tilted relative to the bore axis, and the pair of pins is inserted at an angle in the direction of the shaft between the insides of the arms. The first

The pin is moved obliquely up to the assigned first hole, then pivoted into it and immersed in the first hole in the axial direction deeper than the intended axial bearing length, so that the second pin can be pivoted flush in front of the assigned second hole. Subsequently, by pulling the first pin axially out of the first hole, the second pin is immersed axially into the second hole until both pins with the same axial bearing length are received in the associated holes.

By having a pin pair length that is large relative to the arm spacing, a correspondingly large bearing length of each pin can be achieved, thereby achieving a high load capacity. In order to make assembly possible, the arm spacing relative to the pin pair length must not be too small so that the oblique pivoting described can still be carried out. About this one

Resolving conflicting objectives has been proposed in EP 0 651 170 A1, on the inside of the

Arms should be provided with recesses in the area of the holes. This creates free space between the arms and thus simplifies the assembly of the pins. However, the disadvantage is that the stiffness of the arms is weakened. To compensate for this, the material thickness of the arms can be increased, but this disadvantageously increases the weight and dimensions.

An articulated cross of the type mentioned is described, for example, in US 7,033,277 B1 or US 5,376,051 A. However, the step-shaped recess proposed therein can get caught in the joint fork when the universal joint is inserted, making assembly more difficult.

In view of the problems explained above, it is an object of the present invention to enable improved assembly with a compact and lightweight design.

Presentation of the invention

This object is achieved according to the invention by the joint cross with the features of

Claim 1 and the universal joint according to claim 10. Advantageous developments result from the subclaims.

In a universal joint for a universal joint, comprising two pairs of pins, which have pin axes crossed at right angles to one another in a cross plane, and each

9 BE2022/5530 have a cylindrical lateral surface formed coaxially to the pin axis and an axial end face, the lateral surface and the end face being connected via an edge section running in the circumferential direction, with at least one partial in the edge section

Recess is formed, it is provided according to the invention that the recess has a flat bevel which extends axially from the end face in the direction of the pin axis over 20% to 50% of the axial length of the lateral surface.

The end face of a pin can also be referred to as the axial end face.

In the surrounding edge section, the end face merges into the lateral surface. A pin has a cylindrical basic shape, so that a cross section of the lateral surface outside the recess according to the invention has a circular circumference, which corresponds to a projection of the

End face in the direction of the pin axis corresponds.

In the context of the invention, partial means that the recess extends in the circumferential direction over a partial circumferential section. The recess cuts the lateral surface and into the end face adjoining it in the peripheral section, so that the radial cross section, measured transversely to the pin axis, is partially smaller in the area of the recess than in the remaining circumference of the edge section. This creates an out-of-round shape in the area of the recess

Cross section formed.

The edge section, which is circular in the case of an underlying cylindrical pin, has a non-circular circumferential contour that deviates from the circular shape. In particular, the radial

Cross-sectional dimension in the area of the partial recess is smaller than in the remaining circumferential area, which can still be in the shape of a section of a circle. The recess forms a kind

Recess in the front surface and the lateral surface in the edge area.

According to the invention it is provided that the recess has a flat bevel.

The bevel is formed by a flat surface section that is oblique to the

Pin axis stands and in which a secant of the cylindrical pin cross section lies. The bevel can preferably be inclined at an angle of approximately 45° towards the pin axis. Preferably, the bevel can extend axially from the end face in the direction of the pin axis over 20% to 50% of the axial length of the lateral surface, particularly preferably over 25% to 40%. The advantage is that a flat bevel can be realized with little design and manufacturing effort and can be adapted to different designs and dimensions.

One advantage of the invention is that the partial recess reduces the dimension of the cross-member, measured obliquely to the pin axis. Because the recess is at

* BE2022/5530 is aligned against the inside of the arms during assembly, the trunnion between the insides of the arms can be tilted more. In addition, due to the partially reduced cross-sectional dimension of the first pin in the area of the recess or the reduced end face there, it is possible to move from the inclined position with a narrower arc movement into the first

Hole can be swiveled in. The result can be a larger one in relation to the arm distance

Pin pair length can be realized, so that the bearing length with which each pin is immersed in the assigned bore can be increased in an advantageous manner compared to the prior art with otherwise the same dimensions of the joint fork. This allows a small

Arm spacing and a correspondingly compact and lightweight design of the universal joint can be achieved. Due to the only partial recess according to the invention, the lateral surface in the remaining peripheral area outside the recess can still function as an active bearing surface, whereby a resilient, high radial rigidity of the journal bearing can be ensured.

A further advantage is that the weakening of the joint fork can be completely avoided by the recess in the arm of the joint fork proposed in the prior art.

The recess preferably extends over an axial section of the pin.

This axial section extends from the end face in the direction of the pin axis.

Due to the recess, the cross section of the lateral surface only has a non-circular circumferential contour in a front or outer section axially adjacent to the end face, while the rest, axially remote from the end face, has a non-circular circumferential contour with respect to the joint axis inner area of the lateral surface following the recess can still have a circular cross section.

Preferably, it can be provided that two recesses are arranged radially opposite one another with respect to the pin axis. This symmetrical arrangement makes it advantageously possible to position the universal joint in two opposite orientations.

Ben simplifies assembly, making handling and assembly easier.

In the aforementioned embodiment, the two recesses are preferably arranged mirror-symmetrically to the cross plane.

In a further preferred embodiment, it can be provided that two recesses are formed on two pins, the pin axes of which are perpendicular to one another or, particularly preferably, the pin axes of which intersect at a right angle. Be-

> BE2022/5530 Particularly preferred here is an embodiment in which a recess of a first pin is arranged above a pin plane running through the center of the glene steering cross, which is defined by the pin axes, and a second recess of a second pin is arranged below the is arranged on the same level. In this way, a joint cross can be realized which enables the advantages according to the invention on both forks of the joint.

It is advantageous that a recess is arranged in a peripheral section facing away from the cross plane. The recess is aligned on the universal joint in such a way that it is arranged on an external side of the universal joint, which is directed outwardly away from the universal joint in the normal direction of the cross plane.

This ensures that the pins are inserted into the associated holes in the preferred manner

Mounting position facilitated, in which the pin axis of the second, presently not inserted

Pair of pins, is transverse to the extension of the arms, or in other words the joint cross is aligned like a straight joint.

It can preferably be provided that the recess extends on a secant of a circular pin cross section. The cylindrical pin cross section, as well as the axial one

Projection of the end face in the direction of the pin axis has a circular circumference.

A secant forms a cutting line that is transverse to the tenon axis and intersects the circumferential circle in two points spaced apart in the circumferential direction. The secant thus spans a peripheral section in which the recess according to the invention can be formed.

The advantage here is that a recess running in a straight line along this secant can be implemented with little effort in terms of construction and production technology, for example by means of a simple flat bevel. For example, the recess can be formed by a cutting plane which is inclined diagonally, preferably at approximately 45°, relative to the pin axis and has the secant.

The secant preferably runs at a distance parallel to the cross plane. This allows the

Recess extends in a peripheral section of the lateral and end faces facing vertically outwards from the cross plane. In this way, a particularly assembly-friendly design can be realized by simply aligning the secant.

It is possible for the recess to be concave. For example, the recess can be designed as a channel or groove-like depression with an arcuate recess cross section. The recess can preferably run transversely to the pin axis in a straight line along a secant of the cylindrical pin cross section. This allows a locally enlarged

° BE2022/5530

Clearance can be provided to simplify the insertion movement during assembly.

It can be advantageous for the recess to be designed in a step-shaped manner. For example, the recess can have a V-shaped or rectangular groove-like recess in cross section, which can preferably run transversely to the pin axis in a straight line along a secant of the cylindrical pin cross section. The step edge also runs on one

Secant of the tenon cross section. Such a design can be implemented with little effort in terms of construction and production technology and can be advantageous for assembly.

It can be provided that the lateral surface has a rolling element raceway. The rolling element raceway forms a raceway designed for rolling rolling elements, for example needle rollers or the like. The rolling element raceway can be formed directly on the lateral surface of a pin formed in one piece with the universal joint, or on an inner race of a rolling bearing mounted on the pin, which can be pressed onto the pin as an inner sleeve, for example. In this way, the invention can

Advantages can be realized in a journal bearing designed as a rolling bearing, in which an outer bearing ring of the rolling bearing is arranged in the bore.

A preferred embodiment can provide that the universal joint has a one-piece formed part. This formed part, which is the joint cross or at least the base body of the

Joint cross can form, can preferably be designed as a cold-formed extruded part, preferably made of steel. This results in an advantageously high level of strength, which is high

Resilience and a compact structure enables.

In a universal joint, comprising a universal joint and two joint forks, the joint cross having two pairs of pins, which have pin axes crossed at right angles to one another in a cross plane, and each have a cylindrical lateral surface formed coaxially to the pin axis, and the Joint forks each have two opposite arms, each with a bearing bore, in each of which a pin is rotatably mounted in a pin bearing about a pin axis, it is provided according to the invention that the joint cross is designed according to one of the previously described embodiments or combinations thereof. Due to the inventive design of the universal joint, a compact and lightweight structure of the universal joint can be realized with reduced production and cost expenditure.

Preferably, it can be provided that the lateral surface has an inner rolling element raceway, and the bearing bore has an internally circumferential outer rolling body raceway, wherein rollable rolling bodies are arranged between the inner and outer rolling body raceways. This enables the journal bearing to be designed as a rolling bearing.

A steering shaft for a motor vehicle, comprising two shafts rotatably connected via a universal joint, is characterized according to the invention in that the universal joint is designed according to one of the previously described embodiments or combinations thereof.

A steering shaft usually has two universal joints, which couple the driver-side steering spindle to an output shaft on the steering gear side via an intermediate shaft. The inventive design of the universal joint makes it advantageously more compact and lighter

Structure can be realized with reduced production and costs.

Description of the drawings

Advantageous embodiments of the invention are explained in more detail below with reference to the drawings. Show in detail:

1 shows a schematic perspective view of a steering system comprising universal joints according to the invention,

Figure 2 is an enlarged view of a universal joint from Figure 1,

Figure 3 shows an articulated cross according to the invention in a perspective view,

4 shows the joint cross according to FIG. 2 in a top view perpendicular to the plane of the cross,

5 shows schematically successive steps in the assembly of a universal joint according to FIG. 2,

6 shows a partial view of a pin of a universal joint of a first embodiment according to FIG. 2,

Figure 7 is a partial view of a pin as in Figure 6 of a joint cross in a second

embodiment,

Figure 8 is a partial view of a pin as in Figure 6 of a joint cross in a third

embodiment,

Figure 9 is a partial view of a pin as in Figure 6 of a joint cross in a fourth

embodiment,

Figure 10 shows a cross section CC through the pin according to Figure 6,

Figure 11 shows a cross section DD through the pin according to Figure 6.

Embodiments of the invention

In the various figures, the same parts are always provided with the same reference numbers and are therefore usually only named or mentioned once.

1 shows a steering system 1 of a motor vehicle as a whole in a schematic perspective view. This has a steering column 11, which can be attached to a vehicle body, not shown.

A steering shaft 2 comprises a steering spindle 21 which is rotatably mounted in the steering column 11 about its longitudinal axis (shaft axis), an intermediate shaft 22 and an output shaft 23 which can be connected to a steering gear, not shown. The intermediate shaft 22 is connected on the input and output sides via a device according to the invention Universal joint 3 articulated with the steering spindle 21 and the

Output shaft 23 coupled in a rotationally locking manner. The steering spindle 21, the intermediate shaft 22 and the

Output shaft 23 are also referred to below as shafts 21, 22, 23.

Figure 2 shows an enlarged view of the intermediate shaft 22 and the

Output shaft 23 arranged universal joint 3, which is constructed in the same way as the universal joint 3 arranged between the steering spindle 21 and the intermediate shaft 22.

The universal joint 3 comprises two joint forks 31 of the same design, each of which is mounted in a rotationally fixed manner at the end of one of the shafts 22 and 23. Each joint fork 31 has two arms 32 which extend in the axial direction of the respective shaft 22, 23 and lie opposite each other at an arm distance x.

9 BE2022/5530

The two arms 32 of one joint fork 31 have through holes 33 in the direction of a first pin axis A, and the two arms 32 of the other joint fork 31 point in

Through holes 33 in the direction of a second pin axis B. The pin axes A and B are perpendicular to each other and span a cross plane AB.

A joint cross 4 according to the invention, which is shown separately in FIG. 3 in a perspective view

View and shown in Figure 5 in a top view of the cross plane AB, has a total of four pins 41, which are each arranged in pairs on one of the pin axes A or B and thus each form a pair of pins. The two are in the operating state according to FIG

Pins 41 of such a pair of pins are each rotatably mounted in the bores 33 of a joint fork 31 about the respective pin axis A or B, whereby the pin bearings formed in this way can be designed in a manner known per se as rolling bearings, for example as needle bearings.

Each pin 41 has a cylindrical lateral surface 42 and an axial end face 43, which forms an outer end surface and which is connected to said lateral surface 42 via a circumferential edge section 44. In other words, the lateral surface 42 goes over the

Edge section 44 to the end face 43.

The pin pair length z is the length measured in the direction of a pin axis A or B between the mutually facing end faces 43 of the two pins 41 arranged in pairs on this pin axis A or B, as shown in FIG. The pin pair length z is greater than the arm distance x (see Figure 2 or Figure 5a)).

According to the invention, at least one recess 5 is formed in the edge section 44, which extends over a partial peripheral section of the cylindrical cross section of the lateral surface 42. In the example shown, the recess 5 is designed as a flat bevel, which, based on the circular cross section of the pin 31 in the area of the lateral surface 42, extends over the length of a secant S, which is in the sloping surface of the recess 5 lies.

The orientation of the plane forming the recess 5, which is inclined to the pin axis or B, can be seen in FIGS. 6 and 7, which shows a single pin 41 transversely to the pin axis A (or

B) show. The bevel forms an angle a of preferably approximately 45° with the pin axis A, as shown as an example in FIGS. 3, 4, 6 and 7.

The difference between the embodiments shown in FIGS. 6 and 7 is that in FIG. 6, as well as in FIG. 3, recesses 5 are formed on both sides, facing vertically away from the pin plane AB. According to FIG. 6, the arrangement of the recesses 5 is mirror-symmetrical to the pin plane AB.

Figure 10 shows a cross section CC according to Figure 6 through the cylindrical lateral surface 42, which is clearly circular.

11 shows a cross section DD according to FIG. 6 through the pin 41 in the area of the recesses 5, which is out of round and flattened compared to the circular shape by the secant S.

In the individual figures from Figure 5 a) to d), successive phases are shown in the

Assembly of a joint cross 5 in a joint fork 31 shown.

In the first step according to Figure 5a), the pin axis A of the universal joint 4 is tilted relative to a common bore axis G of the two bores 33 - and, as indicated by the angled arrow - initially positioned straight in the shaft direction between the arms 32, moved to the left, so that the pin 41 on the left in Figure 5a) obliquely to the left in the

Hole 31 of the left arm 32 enters.

Then - as indicated in Figure 5b) with the arrow pointing to the left - the joint cross 5 is moved as far to the left as possible. Through its recess 5 at the bottom in this illustration, the pin 41 can penetrate deeper into the left-hand bore than would be possible without the recess 5.

In addition, the pin 41 on the right has enough air in the area of its recess 5 to the inside of the right arm 31, so that the joint cross 4 can be pivoted in an arc from top to bottom into the left bore 41, as shown in Figure 5c). This results in a superimposed translational movement of the left pin 41 to the left, and a pivoting or rotational movement in which the pin axis A moves towards the bore axis G.

The arcuate movement according to Figure 5c) is continued until the pin axis A is aligned with the bore axis G, as shown in Figure 5d). In the last step - which is indicated in Figure 5d) with the arrow pointing straight to the right - the joint cross 4 is aligned symmetrically relative to the joint fork 31 between the arms 32, so that the pins 41 of a pair of pins are axially at the same depth in the assigned bearing bores 33 dip.

This completes the assembly of one pair of pins and the remaining free one

Pair of pins can be mounted in the other joint fork 31 in the same way.

Figures 8 and 9 show alternative designs of the recess 5. In Figure 8, this is designed as a concave recess in the form of a groove or groove with an arcuately rounded cross-section, which extends transversely to the pin axis A straight in the direction of a secant S. 9 shows a step-shaped recess, which is shown as an example essentially at right angles, with the step edge running on a secant.

The recesses 5 shown on one side in FIGS. 8 and 9 can also, analogous to FIG. 6, be arranged mirror-symmetrically on both sides of the cross plane AB.

It is also conceivable to combine differently shaped recesses 5 according to FIGS. 5 to 8 on a joint cross 4.

The joint crosses 4 shown in the figures can preferably be designed in one piece, for example as a cold-formed extruded part made of steel.

List of reference symbols 1 Steering system 11 Steering column 2 Steering shaft 21 Steering spindle (shaft) 22 Intermediate shaft (shaft) 23 Output shaft (shaft) 3 Universal joint 31 Joint fork 32 Arm 33 Bore 4 Joint cross 41 Pin 42 Lateral surface 43 End surface 44 Edge section 5 Recess x arm distance currently pin pair length

A,B pin axes

AB cross plane a angle

S secant

G bore axis

Claims (12)

PATENT CLAIMS 1. Universal joint (4) for a universal joint (3), comprising two pairs of pins (41), which have pin axes (A, B) crossed at right angles to one another in a cross plane (AB), and each of which has one coaxial to the pin axis (A , B) have a cylindrical lateral surface (42) and an axial end face (43), the lateral surface (42) and the end face (43) being connected via an edge section (44) running in the circumferential direction, wherein in at least one partial recess (5) is formed in the edge section (44), characterized in that the recess (5) has a flat bevel which, measured axially from the end face in the direction of the pin axis, is over 20% to 50% of the axial Length of the lateral surface extends. 2. Universal joint according to claim 1, characterized in that two recesses (5) are arranged radially opposite one another with respect to the pin axis (A, B). 3. Universal joint according to one of the preceding claims, characterized in that the recess (5) extends over an axial section of the pin (41). 4. Joint cross according to one of the preceding claims, characterized in that the recess (5) is arranged in a peripheral section facing away from the cross plane (AB). 5. Universal joint according to one of the preceding claims, characterized in that the recess (5) extends on a secant (S) of a cylindrical pin cross section. 6. Universal joint according to one of the preceding claims, characterized in that the recess (5) is concave. 7. Universal joint according to one of the preceding claims, characterized in that the recess (5) is designed in a step shape. 8. Universal joint according to one of the preceding claims, characterized in that the lateral surface (42) has a rolling element raceway. 9. Universal joint according to one of the preceding claims, characterized in that it has a one-piece formed part. 10. Universal joint (3), comprising a universal joint (4) and two joint forks (31), the universal joint (4) having two pairs of pins (41) which have pin axes (A) lying at right angles to one another in a cross plane (AB). B), and each have a cylindrical lateral surface (42) formed coaxially to the pin axis (A, B), and the joint forks (31) each have two opposite arms (32), each with a bearing bore (33), in which each one pin (42) is rotatably mounted in a pin bearing about a pin axis (A, B), characterized in that the universal joint (4) is designed according to one of the preceding claims 1 to 9. 11. Universal joint according to claim 10, characterized in that the lateral surface (42) has an inner rolling body raceway, and the bearing bore (33) has an internally circumferential outer rolling body raceway, rollable rolling bodies being arranged between the inner and outer rolling body raceways. 12. Steering shaft for a motor vehicle, comprising two shafts (21, 22, 23) rotatably connected via a universal joint (3), characterized in that the universal joint (3) is designed according to one of the preceding claims 10 to 11.