WO2020048562A1

WO2020048562A1 - Belt element and continuously variable transmission having same

Info

Publication number: WO2020048562A1
Application number: PCT/DE2019/100746
Authority: WO
Inventors: Manuel Falk
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2018-09-04
Filing date: 2019-08-20
Publication date: 2020-03-12
Also published as: DE102018121505A1

Abstract

The invention relates to a belt element (10) for a transmission of a motor vehicle, in particular for a continuously variable transmission, having a plate link chain (12) comprising an arrangement (14) of thrust pieces (16) aligned transverse to the running direction of the belt element (10) and plate links (18) arranged parallel to the running direction, wherein: the thrust pieces (16) engage in openings (20) of the plate links (18) and form joints (24) by means of which the plate links (18) are connected in an articulated manner; the plate links (18) can be grouped in plate link sequences (26) of directly successive plate links (18) and each of the plate link sequences (26) extends from one to the other flank (30, 32) of the plate link chain (12) about a main axis (28) of said plate link sequence running perpendicular to the running direction (22); and the plate links (18) of each one of the plate link sequences (26) are arranged one behind the other in two or three plate link rows (P1, P2, P3) that are directly adjacent to one another and run parallel to the corresponding main axis (28) of the plate link sequence (26). According to the invention, the arrangement of the plate links (18) in the corresponding plate link sequence (26) is asymmetrical with respect to the requirements for punctual symmetry and the requirements for axial symmetry. The invention further relates to a continuously variable transmission for a motor vehicle, having a first V-pulley, a second V-pulley, and a belt element (10) of this kind, which is arranged in the torque flow between the first V-pulley and the second V-pulley.

Description

Umschlinqunqsmittel and CVT transmission with the same

The invention relates to a belt means for a, in particular continuously variable, transmission of a motor vehicle, with a link chain which has an arrangement of pressure pieces oriented transversely to the running direction of the belt means and links arranged parallel to the direction of travel, the pressure pieces engaging in openings in the links and Joints form links by means of which the plates are connected in an articulated manner, the plates being able to be grouped in plate sequences of immediately successive plates and each of the plate sequences extending from one to the other flank of the plate chain around a main axis of this plate sequence running perpendicular to the running direction, and wherein the tabs of each of the tab sequences are arranged one behind the other in two or three immediately adjacent rows of tabs running parallel to the respective main axis.

The invention further relates to a continuously variable transmission for a motor vehicle, having a first pair of conical disks, a second pair of conical disks and a belt means, which is arranged in the torque flow between the first pair of conical disks and the second pair of conical disks.

A corresponding continuously variable transmission is also referred to as a CVT transmission (CTV: Continuously Variable Transmission). The belt means is arranged in the torque flow between a first pair of conical disks of the transmission and a second pair of conical disks.

The document DE 30 27 834 A1 shows a belt means for a continuously variable transmission of a motor vehicle, with a link chain which has an arrangement of pressure pieces oriented transversely to the running direction of the belt means and links arranged parallel to the direction of travel, the pressure pieces in openings of the links intervene and form joints via which the tabs are connected in an articulated manner. The tabs can be grouped in tab sequences of immediately successive tabs and each of the tab sequences extends from one to the other flank of the link chain around a main axis of this link sequence running perpendicular to the running direction. The tabs are in an example in the Two-link assembly and, in another example, arranged in a three-link assembly, so that the links of each link sequence are arranged one behind the other in two or three immediately adjacent rows of links running parallel to the respective main axis of this sequence.

NVH behavior (NVH: Noise, Vibration, Harshness) and strength are the dominant issues in the further development of belts with link chains for the above-mentioned gears. There is also a constant need to improve efficiency and wear and to make the running radius as small as possible.

It is the object of the invention to provide measures by means of which the looping means achieves sufficient strength with good acoustic behavior during operation.

The object is achieved according to the invention by the features of independent claims 1 and 10. Preferred embodiments of the invention are specified in the subclaims, which can each represent an aspect of the invention individually or in combination.

In the belt means according to the invention for a, in particular continuously adjustable, transmission of a motor vehicle, with a link chain which has an arrangement of pressure pieces oriented transversely to the running direction of the belt means and straps arranged parallel to the running direction, the pressure pieces in openings of the Engage tabs and form joints by means of which the tabs are connected in an articulated manner, the tabs being able to be grouped in tab sequences of immediately successive tabs and each of the tab sequences moving from one flank to another around a main axis of this tab sequence running perpendicular to the direction of travel extends the link chain and the links of each of the link sequences are arranged one behind the other in two or three directly adjacent link rows running parallel to the respective main axis, it is provided that the arrangement of the links in the respective link sequence also Regarding the requirements of a point symmetry and the requirements of an axis symmetry is asymmetrical. Such an asymmetry means that the chain load designed more evenly and adapted to the individual stiffness differences of the gear discs. In other words, the link chain is adapted by means of a specifically designed asymmetrical link pattern, whereby a more even contact pattern in the chain is achieved with acoustics felt to be pleasant.

An arrangement of the tabs in the so-called two-link assembly results in link sequences with two rows of links. If the tabs are arranged in a so-called three-link assembly, there are tab sequences with three rows of tabs.

According to a preferred embodiment of the invention, the tab rows have the same number of tabs for each tab sequence. In the case of a tab sequence with, for example, eighteen tabs in three rows of tabs, each of the rows has six tabs.

According to a further preferred embodiment of the invention, the length of the tabs and the length of their openings in the running direction are the same for all tabs. In particular, the tabs are all shaped identically. The advantages mentioned above result solely from the asymmetrical arrangement of the tabs.

It is advantageously provided that each of the tab sequences has eight or twelve or eighteen tabs. When the straps are arranged in a two-strap association, eight or twelve straps per strap sequence or four or six straps per strap row are often provided. When the tabs are arranged in a three-link assembly, there are often twelve or eighteen tabs per link sequence or four or six tabs per row of tabs.

According to yet another preferred embodiment of the invention, the distance between the joints and the adjacent joints in the link chain is constant. Such a configuration is, for example, from the publication mentioned at the beginning

DE 30 27 834 A1 known. In order to achieve a constant distance between adjacent joints with simple means, the tabs are in particular constructed identically.

In a preferred embodiment of the invention, the wrapping means is designed as a pure wrapping chain formed by the link chain. A der- like belting is characterized by high strength with a relatively simple structure.

Alternatively, it is provided that the wrapping means also has an endless belt arranged on the link chain. In other words, the wrapping means is formed by a wrapping chain with an endless belt running in parallel. Such a design generally has a favorable effect on the acoustic behavior.

In a further preferred embodiment of the invention, the pressure pieces for forming the joints are designed as weighing pressure pieces engaging in pairs in the openings of the tabs. Such an embodiment is known, for example, from the document DE 30 27 834 A1 mentioned at the beginning.

Finally, it is advantageously provided that the pressure pieces protrude from the arrangement on the flanks of the belt and have securing elements for securing the tabs and / or pressure pieces against loss. Various types of securing elements are known from the literature.

In the case of the continuously variable transmission for a motor vehicle according to the invention, with a first pair of conical disks, a second pair of conical disks and a belt that is arranged in the torque flow between the first pair of conical disks and the second pair of conical disks, it is provided that the belt is designed as the above-mentioned belt .

In the following, the invention is explained by way of example with reference to the attached drawings using preferred exemplary embodiments, the features shown below being able to represent an aspect of the invention both individually and in combination. It shows:

1: a section of a link chain forming a looping means in a side view, 2: a link sequence of the link chain of a belt according to a preferred embodiment of the invention,

3: a link sequence of the link chain of another belt and

Fig. 4 shows a link sequence of the link chain still another belt.

1 shows a wrap means 10 which is designed as a wrap chain, which in turn is essentially designed as a link chain 12. The main assembly of the link chain 12 is an arrangement 14 with pressure pieces 16 and (connecting) links 18, which are generally arranged either in a two-link linkage or in a three-link linkage. The terms two-link bandage and three-link bandage are introduced and explained in the publication DE 30 27 834 A1 mentioned at the beginning using appropriate examples, so that their meaning will not be described again here.

The tabs 18 have openings 20, in which the pressure pieces 16 engage. While the tabs 18 are aligned along a running direction (double arrow 22) of the wrapping means 10, the pressure pieces 16 are aligned transversely, more precisely perpendicularly, to this running direction.

The belt means 10 is set up for the transmission of forces and torques in a cone pulley belt transmission (not shown), such a cone pulley belt transmission being arranged, for example, in the drive train of a motor vehicle between a drive machine and the driven axle. The continuously variable transmission adjusts the transmission ratio to the respective driving and operating conditions of the drive machine or to the driver's requirements for the drive machine, for example due to an accelerator pedal actuation.

The belt means 10 connects two cone pulley pairs or cone pulley sets in the power flow or torque flow within the cone pulley belt transmission, whereby a variation of the transmission ratio with respect to the axis of the respective cone pulley pairs by varying the running radius of the belt pulley. can be realized and controlled in a targeted manner. This can be controlled in a targeted manner by means of a control unit. One pair of conical disks of the transmission is connected or connectable to at least one transmission input shaft and the other pair of conical disks is connected or can be connected to an output shaft of the transmission.

The link chain 12 shown in FIG. 1 has the arrangement 20 of links 24 and the pressure pieces 22. The pressure pieces 22 are designed as weighing pressure pieces (abbreviated WDS) and engage in pairs in the openings 26 of the tabs 24 to form a joint 30 each. The joint 30 formed from two weighing pressure pieces is often also referred to as a weighing joint. As already mentioned above, the tab arrangement of the tabs 24 can be selected, for example, in a two-link assembly or in a three-link assembly.

The weighing pressure pieces 22 arranged in pairs have sides facing one another, on which they roll against one another or on which they can slide against one another, so that the tabs 24 are connected to one another in an articulated manner by means of the pressure pieces 22 formed in this way. In order to hold and guide the pressure pieces 16 in the paired arrangement, the tabs 18 have guide cams projecting into the openings 20.

On the flanks of the link chain 12 lying opposite one another in the longitudinal direction of the pressure pieces 16, the pressure pieces 16 each protrude with end sections from the arrangement of the links 18 (not explicitly shown). The link chain 12 also has securing elements (not shown) designed as pins (retaining pins) for securing the links 18 and / or pressure pieces 16 against loss. The pins form projections which prevent the arrangement 14 of pressure pieces 16 and tabs 18 from falling apart.

The tabs 18 of the link chain 12 can be grouped into identically constructed link sequences 26, which run transversely to the direction of travel (double arrow 22) of the belt 10, directly following links 18. Each of FIGS. 2-4 shows such a link sequence 26, which defines the respective arrangement of the links 18 in the respective link chain 12. In other words, the La- leg chains 12 with the respective link sequences of FIGS. 2, 3 and 4, that is to say by arranging the links 18 within the link chain 12.

FIG. 2 shows a link sequence 26, which runs around a main axis 28 of this link sequence 26 running perpendicular to the direction of travel (double arrow 22) from one side to the other flank 30, 32 of the link chain 12 in a kind of “zigzag line” - stretches. The main axis 28 forms a kind of center of gravity line of the link sequence 26. Since the links 18 of the link chain 12 are arranged in a three-link arrangement, the links 18 of the link sequence 26 are in three directly adjacent link rows P1 running parallel to the main axis 28 of the link sequence 26 , P2, P3 arranged one behind the other. The arrangement of the tabs 18 in the tab sequence 26 is asymmetrical with respect to the requirements of point symmetry and the requirements of axis symmetry. In the example, the tab sequence 26 has eighteen tabs 18 with the numbering # 1 to # 18 in three tab rows P 1, P2, P3, so that each of the three tab rows P1, P2, P3 thus has six tabs 18. Tabs P1 are tabs 18 # 2, # 4, # 7, # 9, # 16 and # 17. The tabs 18 # 3, # 8, # 10, # 14, # 15 and # 18 are in the row of tabs P2. The tabs 18 # 1, # 5, # 6, # 11, # 12 and # are in the row of tabs P3. 13.

At this point it should be noted once again that the link sequence 26 shown represents all link sequences 26 of the corresponding link chain 12.

Due to the specifically asymmetrical link chain 12, the chain load is made more uniform than with a symmetrically designed link chain 12 and additionally adapted to the individual differences in stiffness of the cone pulley pairs referred to as fixed and displacement pulleys. The chain 12 is adapted by specifically constructing the tab pattern asymmetrically. A more even contact pattern in the chain 12 can thereby be achieved.

FIGS. 3 and 4 now show link sequences 26 of link chains 12 in which the arrangement of the links 18 in the respective link sequence 26 is point-symmetrical (FIG. 3) or axisymmetric (FIG. 4) with respect to a central axis transverse to the main axis 28. In the example of FIG. 3, the tab sequence 26 also has eighteen tabs 18 with the numbering # 1 to # 18 in three tab rows P 1, P2, P3, so that each of the three tab rows P1, P2, P3 thus has six tabs 18. The tabs 18 # 3, # 4, # 9, # 11, # 14 and # 17 are in tab row P1. In the row of tabs P2 there are tabs 18 # 1, # 6, # 7, # 12, # 13 and # 18. In the row of tabs P3 there are tabs 18 # 2, # 5, # 8, # 10, # 15 and # 16.

In the example of FIG. 4, the tab sequence 26 again has eighteen tabs 18 with the numbering # 1 to # 18 in three tab rows P 1, P2, P3, so that each of the three tab rows P1, P2, P3 thus has six tabs 18. Tabs P1 are tabs 18 # 2, # 5, # 8, # 11, # 14 and # 17. The tabs 18 # 1, # 6, # 7, # 12, # 13 and # 18 are in the row of tabs P2. The tabs 18 # 3, # 4, # 9, # 10, # 15 and # are in the row of tabs P3. 16.

Reference list

10 straps

12 link chain

14 arrangement

16 pressure pieces

18 tabs

20 openings

22 double arrow

24 joint

26 sequence of tabs

28 main axis

30 right flank (link chain)

32 left flank (link chain)

# 1 # 18 tab number

P1 first row of plates in the series of plates P2 second row of plates in the series of plates P3 third row of plates in the series of plates

Claims

1. Wrapping means (10) for a, in particular continuously variable, transmission of a motor vehicle with

a link chain (12) which has an arrangement (14) of pressure pieces (16) oriented transversely to the running direction of the belt means (10) and links (18) arranged parallel to the running direction,

the pressure pieces (16) engaging in openings (20) of the straps (18) and forming joints (24) by means of which the straps (18) are connected in an articulated manner,

wherein the tabs (18) can be grouped in tab sequences (26) of successively following tabs (18) and each of the tab sequences (26) extends around a main axis (28) of this tab sequence (26) perpendicular to the running direction (22) one to the other flank (30, 32) of the link chain (12) and the links (18) of each of the link sequences (26) in two or three parallel to the respective main axis (28) of the link sequence (26), immediately adjacent beard rows of tabs (P1, P2, P3) are arranged one behind the other,

characterized in that

the arrangement of the plates (18) in the respective plate sequence (26) is asymmetrical with respect to the requirements of point symmetry and the requirements of axis symmetry.

2. Wrapping means (10) according to claim 1, characterized in that in each strap sequence (26) the strap rows (P1, P2, P3) have the same number of tabs (18).

3. Wrapping means (10) according to claim 1 or 2, characterized in that the length of the tabs (18) and the length of their openings (20) in the running direction is the same for all tabs (18).

4. wrap means (10) according to claim 3, characterized in that the tabs (18) are identically shaped.

5. wrap means (10) according to any one of claims 1 to 4, characterized in that each of the plate sequences (26) has eight or twelve or eighteen plates (18).

6. wrap means (10) according to any one of claims 1 to 5, characterized in that the distance of the joints (24) to the adjacent joints (24) in the link chain (12) is constant.

7. wrap means (10) according to one of claims 1 to 6, characterized in that the wrap means (10) is designed as a loop chain formed by the link chain (12).

8. wrap means (10) according to one of claims 1 to 6, characterized by an on the link chain (12) arranged endless belt.

9. Wrapping means (10) according to one of claims 1 to 8, characterized in that the pressure pieces (14) for forming the joints (24) are designed as paired pressure pieces engaging in the openings (20) of the tabs (16).

10. Infinitely variable transmission for a motor vehicle, with a first cone pulley pair, a second cone pulley pair and a belt means (10) which is arranged in the torque flow between the first cone pulley pair and the second cone pulley pair, characterized in that the looping means (10) is formed according to one of the preceding claims.