CVT PLATE LINK CHAIN HAVING CLEAN CONTACT BETWEEN PRESSURE PIECE AND PLATE

Abstract

A plate link chain for a motor vehicle drive having a continuously variable transmission includes a pressure piece with a first bearing face and a second bearing face, and a plate with a third bearing face and a fourth bearing face. The first bearing face and the third bearing face bear against one another to form a force transmitting outer contact region relative to a rotation direction of the plate link chain, and the outer contact region forms an outer contact face that is linear or flat and encloses an angle α that is ≥160° and ≤180°. The second bearing face and the fourth bearing face bear against one another to form a force transmitting inner contact region relative to the rotation direction, and the inner contact region forms an inner contact face enclosing an angle that is ≥90° and ≤135°.

Claims

1.-10. (canceled)

11. A plate link chain for a motor vehicle drive having a continuously variable transmission, comprising: a pressure piece comprising a first bearing face and a second bearing face; a plate comprising a third bearing face and a fourth bearing face, the plate being articulated to another plate by the pressure piece, wherein: the first bearing face and the third bearing face bear against one another to form a force transmitting outer contact region relative to a rotation direction of the plate link chain; the outer contact region forms an outer contact face that is linear or flat and encloses an angle α that is ≥160° and ≤180°; the second bearing face and the fourth bearing face bear against one another to form a force transmitting inner contact region relative to the rotation direction; and the inner contact region forms an inner contact face enclosing an angle β that is ≥90° and ≤135°.

12. The plate link chain of claim 11 wherein a shape of the inner contact face comprises a circular-cylindrical cylinder or a sphere.

13. The plate link chain of claim 11 wherein: the inner contact face has an angle δ facing the outer contact face which is ≥5° and ≤30°; or the inner contact face has an angle γ facing away from the outer contact face which is ≥0° and ≤15°.

14. The plate link chain of claim 11 wherein: the pressure piece comprises a fifth bearing face; the plate comprises a sixth bearing face; the fifth bearing face and the sixth bearing face bear against one another for form a force transmitting third contact region forming a third contact face; one of the outer contact face, the inner contact face, or the third contact face is arranged on one side of a longitudinal center axis of the plate link chain; and the other two of the outer contact face, the inner contact face, or the third contact face are arranged on the other side of the longitudinal center axis.

15. The plate link chain of claim 14 wherein the one of the outer contact face, the inner contact face, or the third contact face is aligned at an angle between 35° and 55° to the longitudinal center axis.

16. The plate link chain of claim 14 wherein: one of the other two of the outer contact face, the inner contact face, or the third contact face is aligned parallel to the longitudinal center axis; and the other one of the other two of the outer contact face, the inner contact face, or the third contact face is aligned transversely to the longitudinal center axis.

17. The plate link chain of claim 14 wherein: the plate comprises a longitudinal bracket and a transverse bracket; one of the other two of the outer contact face, the inner contact face, or the third contact face is formed on the longitudinal bracket; and the other one of the other two of the outer contact face, the inner contact face, or the third contact face is formed on the transverse bracket.

18. The plate link chain of claim 14 wherein the inner contact face or the third contact face is flat.

19. The plate link chain of claim 14 wherein the other two of the outer contact face, the inner contact face, or the third contact face adjoin one another or merge into one another.

20. The plate link chain of claim 11 wherein the angle β is ≥110° and ≤120°.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In the following, the disclosure is explained in more detail with reference to drawings. In the drawings:

[0026] FIG. 1 shows a schematic representation of part of a plate of a plate link chain known from the prior art by the applicant (for example CL05 or CL06 or CL07),

[0027] FIG. 2 shows a schematic representation of part of a plate of a further plate link chain known from the prior art by the applicant (for example CL05 or CL06 or CL07),

[0028] FIG. 3 shows a schematic representation of part of a plate of a plate link chain according to a first embodiment of the disclosure and

[0029] FIG. 4 shows a schematic representation of a second embodiment of the disclosure.

[0030] The figures are only schematic in nature and serve only for comprehension of the disclosure. The same or equivalent elements are provided with the same reference symbols.

DETAILED DESCRIPTION

[0031] FIGS. 1 and 2 show schematic representations of subsections from the plate link chains known from the prior art.

[0032] FIG. 1 shows a plate link chain 1 with two plates 2 and 3. The plate 2 includes an upper bracket 4A and a lower bracket 4B. The plate 2 includes an opening 5 into which a total of four rocker pressure pieces 6, 7, 8, 9 engage. The rocker pressure pieces 8 and 9 represent a first pair of rocker pressure pieces. The rocker pressure pieces 6 and 7 represent a second pair of rocker pressure pieces. The first pair of rocker pressure pieces with the rocker pressure pieces 8 and 9 represents a first rocker joint which couples the two plates 2 and 3 to one another. The rocker pressure pieces 6, 7 and 8, 9 of a pair of rocker pressure pieces bear against one another in rolling regions. In the embodiment shown, a rolling point 10 is arranged in the middle of the rolling regions.

[0033] A first flat contact face 12 is formed between the rocker pressure piece 9 and a bracket connection area which connects the upper bracket 4A to a side bracket 11, which is also referred to as a transverse bracket 11. A second flat contact face 13 is formed between the rocker pressure piece 6 and a bracket connection area which connects the lower bracket 4B to the side bracket 11. The flat contact faces 12 and 13 represent defined bearing faces between the rocker pressure piece 6 and the plate 2. The rocker pressure piece 6 is in contact with the plate 2 in a corresponding manner via the opposing contact faces 12, 13.

[0034] The forces F1 and F2 transmitted via the contact faces 12, 13 between the pressure piece 9 and the plate 2 are shown in FIG. 1. The lines of action of the forces F1 and F2 each run through the rolling point 10 and an intersection point S1 or S2 of neutral fibers 30, indicated by dashed lines, of the brackets 4A, 4B and 11 of the plate 2. The angles of inclination of the lines of action of the forces F1 and F2 relative to the longitudinal center axis 14 of the plate link chain are denoted by α1 and α2 in FIG. 1.

[0035] A pressure piece 15 of another plate link chain known from the prior art is shown in FIG. 2. Together with a plate, not shown in the figure, which is designed essentially similar to the plate 2 in FIG. 1, the pressure piece 15 forms two contact faces 16, 17 which are designed essentially transversely to the longitudinal center axis 33 on the transverse bracket. With the exception of the design of the bearing faces 16, 17, the plate corresponds to the plate 2 shown in FIG. 1.

[0036] The design of the contact faces 16, 17 according to FIG. 2 offers the advantages of high chain rigidity in the longitudinal direction, low contact slip when the load changes, and a defined installation position. In the case of a relatively low load transmitted via the plate link chain, the contact is mainly in the vertical area of the transverse brackets. This creates a flat force vector F3 and a relatively large lever arm H3, which leads to a large deformation of the plate. When a relatively high load is transferred, the contact is shifted more in the direction of the longitudinal bracket to the contact points 16′ and 17′ as a result of a larger deformation. This increases the radial force component. As a result, the force vector F3′ becomes steeper, which counteracts the bracket bending. This characteristic has the disadvantage that the force vector is initially relatively flat when the load is relatively low, with the result of a large degree of bracket bending, constriction of the plate and increased loads on the plate. The direction of the force vector reacts very sensitively to geometric deviations. This leads to high variations in chain strength.

[0037] The embodiment according to FIG. 1 serves in the context of a further development of the embodiment according to FIG. 2 to achieve more defined force vectors that react less sensitively to geometric deviations. The result is a smaller variation in the chain strength and a steeper position of the force vectors F1, F2 to reduce bracket bending and/or plate constriction. The disadvantage of this embodiment is a lower chain stiffness in the longitudinal direction, increased slip in the event of load changes such as chain rotation in the contact region between the plate and the pressure piece/rocker pressure piece, the risk of wear-based failure and the risk of incorrect positioning of the pressure piece (a slightly twisted pressure piece might not come to the correct installation position due to the acting load).

[0038] FIG. 3 shows part of a plate 18 of a plate link chain according to an example embodiment. The plate 18 includes an upper bracket 19 and a lower bracket 20, both of which are also referred to as longitudinal bracket 19, 20, and a side bracket 21, which is also referred to as transverse bracket 21. The two longitudinal brackets 19, 20 are connected to each other on the one hand with the transverse bracket 21 and on the opposite side with a further transverse bracket (not shown in the figure), so that the two longitudinal brackets 19, 20 with the two transverse brackets 21 form the plate 18 which is closed in the circumferential direction. The plate 18 thus includes an opening 22 surrounded by the longitudinal brackets 19, 20 and the transverse brackets 21. The transverse bracket 21 is arranged essentially orthogonally to the longitudinal brackets 19, 20 and the longitudinal center axis 29 of the plate 18.

[0039] In the opening 22, a total of four pressure pieces are arranged, of which only one pressure piece 23 is shown to allow better clarity of the figure. The pressure pieces 23 are also referred to as rocker pressure pieces 23 and are arranged in such a way that two pressure pieces 23 each form a pair of rocker pressure pieces. Each pair of rocker pressure pieces forms a rocker joint, with which the plate 18 and a further plate adjoining this (not shown in the figure) are or will be articulated to one another. The rocker pressure pieces 23 of a pair of rocker pressure pieces bear against each another in rolling regions 24 and roll against one another thereon. In FIG. 3, the rolling region 24 and a rolling point 25 located centrally therein are shown.

[0040] According to the embodiment, a total of, for example, exactly three bearing or contact faces 26, 27, 28 are formed and arranged between the pressure piece 23 and the plate 18. In each case, a bearing face 26 is arranged on one side of the longitudinal center axis 29 of the plate link chain or plate 18. The two remaining bearing faces 27, 28 are arranged on the other side of the longitudinal center axis 29. In this way, it is ensured that a pressure piece 23 and a plate 18 always bear against each other via exactly three contacts for force transmission, so that a clearly defined contact is effected. With the exception of the design of the bearing faces 26, 27, 28, the plate 18 corresponds to the plate 2 shown in FIG. 1.

[0041] In the embodiment shown in FIG. 3, the bearing face 26 is oriented obliquely at an angle of approximately 45′ to the longitudinal center axis. The bearing face 28, on the other hand, is aligned on the longitudinal bracket 20 parallel to the longitudinal center axis 29. Finally, the bearing face 27 is aligned on the transverse bracket 21 transversely to the longitudinal center axis 29. All bearing faces 26, 27, 28 are designed to be flat. As a result of this design of the bearing faces 26, 27, 28, the force vector transmitted via the bearing face 26 can be aligned in a more defined manner, e.g., more steeply, than in the prior art. The plate link chain therefore reacts less sensitively to geometrical deviations, which results in a lower variation of the chain strength. In addition, a high chain rigidity in the longitudinal direction, a low contact slip in the event of load changes, a defined installation position of the pressure piece and a large contact region can be achieved.

[0042] For the sake of completeness, it should be pointed out that the arrangement shown in FIG. 3 can also be mirrored horizontally within the scope of the invention, i.e. that the oblique contact 26 below and the bearing faces 27, 28 above can be formed in the side bracket 19 and transverse bracket 21.

[0043] An example embodiment is shown schematically in FIG. 4. In this embodiment, the contact region 26 defines a first contact face 31. Furthermore, the contact regions 27 and 28 merge into one another (seamlessly/without transition) and define a second contact face 32.

[0044] There is an angle α in the area of the first contact face. It should be mentioned that there is usually a line contact there in the (almost) unloaded state, recognizable as a point in the section of FIG. 4, whereas, in the loaded state, this linear contact region widens to form a contact face, namely the first contact face 31, which is bent and thereby defines the angle α.

[0045] An angle β is enclosed in the area of the second contact face 32. The angle β is the sum of a 90° angle and the two angles δ and γ.

REFERENCE NUMERALS

[0046] 1 Plate link chain [0047] 2 Plates [0048] 3 Plates [0049] 4A, B Bracket, longitudinal bracket [0050] 5 Opening [0051] 6 Pressure piece, rocker pressure piece [0052] 7 Pressure piece, rocker pressure piece [0053] 8 Pressure piece, rocker pressure piece [0054] 9 Pressure piece, rocker pressure piece [0055] 10 Rolling point [0056] 11 Bracket, transverse bracket [0057] 12 Contact face [0058] 13 Contact face [0059] 14 Longitudinal center axis [0060] 15 Pressure piece [0061] 16 Contact face [0062] 17 Contact face [0063] 18 Plate [0064] 19 Bracket, longitudinal bracket [0065] 20 Bracket, longitudinal bracket [0066] 21 Bracket, transverse bracket [0067] 22 Opening [0068] 23 Pressure piece, rocker pressure piece [0069] 24 Rolling region [0070] 25 Rolling point [0071] 26 Contact face [0072] 27 Contact face [0073] 28 Contact face [0074] 29 Longitudinal center axis [0075] 30 Neutral fiber [0076] 31 First contact face [0077] 32 Second contact face [0078] 33 Longitudinal center axis