DE102020129936B4 - Link chain and conical pulley belt transmission - Google Patents

Abstract

Link chain (1) for a conical pulley belt transmission with continuously variable transmission ratio, the rocker joints (4) of which connect the individual link packs with several link plates (2) and form pairs of rocker pressure pieces (5) that are inserted into recesses (20) in the link plates (2). are formed with rolling surfaces (W) that are supported on one another,- with three chain links (3; 3-1, 3-2, 3-3) arranged adjacent in the circumferential direction of the link chain (1) forming a chain link group (30),- with the link chain (1) is formed by a large number of chain link groups (30) placed directly next to one another in the direction of rotation, and wherein the link plates (2) within a chain link group (30) are point-symmetrical to the center point (P) of the chain link group, viewed over the entire width of the link chain (1). (30) are arranged, characterized in that each chain link group (30) has a width (B) of exactly thirty link plates (2) a predetermined link plate width (b1),-- wherein the middle chain link (3-2) of the chain link group (30) has link plates (2) on the link plate positions (KLP) one (KLP1), six (KLP6), eight (KLP8), eleven (KLP11), fourteen (KLP14), seventeen (KLP17), twenty (KLP20), twenty-three (KLP23), twenty-five (KLP25) and thirty (KLP30),-- with a first chain link adjacent to the middle chain link (3-2). (3-1) Link plates (2) on link plate positions (KLP) three (KLP3), four (KLP4), nine (KLP9), twelve (KLP12), fifteen (KLP15), eighteen (KLP18), twenty-one (KLP21), twenty-four (KLP24), twenty-six (KLP26) and twenty-nine (KLP29), and-- wherein a second chain link (3-3) adjacent to the middle chain link (3-2) has link plates (2) on the link plate positions (KLP) two (KLP2 ), five (KLP5), seven (KLP7), ten (KLP10), thirteen (KLP13), sixteen (KLP16), nineteen (KLP19), twenty-two (KLP22), twenty-seven (KLP27) and twenty-eight (KLP28) occupied.

Description

The present invention relates to a plate link chain for a conical pulley belt transmission with infinitely variable transmission ratio, whose rocker joints connecting the individual chain links formed by plate sets with several link plates are designed as pairs of rocker pressure pieces with rolling surfaces supported on one another and pushed into recesses in the chain plates. In this case, in each case three chain links arranged adjacently in the direction of rotation of the link chain form a chain link group. The link chain is formed by a large number of chain link groups placed directly next to one another in the direction of rotation, the link plates within a chain link group being arranged point-symmetrically to the center point of the chain link group over the entire width of the link chain. Furthermore, the invention relates to a conical pulley belt transmission for a motor vehicle that can be steplessly adjusted in terms of transmission ratio.

A link chain is used as a looping means in a mechanically adjustable continuously variable transmission of a motor vehicle. A mechanically adjustable continuously variable transmission, known as Continuously Variable Transmission, or CVT for short, allows the ratio to be continuously adjusted without any interruption in traction. The link chain has chain links lined up next to each other, which are connected by pressure pieces. In the case of the chains currently on the market, the pressure pieces are axially secured using securing elements, for example short pieces of wire.

• Mit ihr werden niedrige Verbräuche und eine hervorragende Fahrdynamik erzielt. Das ist durch die Wiegegelenk-Konstruktion der Laschenkette möglich, mit der kleine Laufkreise auf den Kegelscheiben und damit eine hohe Getriebespreizung realisiert werden.

The link chain (or CVT link chain or CVT chain) has the following properties:

• It achieves low consumption and excellent driving dynamics. This is possible thanks to the rocker link design of the link chain, with which small running circles on the conical pulleys and thus a high gear spread can be achieved.

High torques can be transmitted with the CVT chain. Thicker shackles, which can be used optionally, on the outside of the strand even out the stress distribution.

The element is characterized by low internal friction losses due to the rolling of the rocker pressure pieces and thus guarantees good transmission efficiency.

The CVT chain is insensitive to track misalignment thanks to the optionally crowned end faces of the rocker pressure pads. In combination with optionally curved conical pulleys, the additional component of the toe offset that inevitably occurs during adjustment is reduced. Furthermore, the CVT chain is insensitive to pulley set deformation under load, angular errors and relative torsion between the fixed and movable conical pulley. It therefore does not require any ball guides for the axially movable conical pulleys.

When using the CVT chain, there are low axial forces on the primary pulley set. This means that low hydraulic pressure can be used for the given cylinder areas, another advantage in terms of transmission efficiency.

The strand can be designed as a three-tab joint, thus enabling a short basic division. With a short chain link, only the shackle of a plate is located between the adjacent joints.

A second lug length makes it possible to achieve favorable acoustic behavior by mathematically optimizing the pitch sequence of long and short lugs.

From the EP 2 587 091 B1 there is known a link chain for a continuously variable transmission of an automotive vehicle, wherein an assembly of elements of the link chain is formed by three successive chain elements, the arrangement patterns in the respective element assemblies being the same, and the number of links divided into three link units, which are in each element assembly are 9, 8, and 8 respectively.

The publication WO 2017/032 372 A1 discloses another link chain for a continuously variable transmission in the so-called three-link association with three consecutive chain elements.

The invention is based on the object of providing a link chain or a continuously variable transmission with a link chain, with this(these) being further optimized with regard to wear properties. Advantageously, a reduced load on the link plates and the rocker pressure pieces should be achieved by the invention.

This object is achieved by a link chain for a conical pulley belt transmission with an infinitely variable transmission ratio having the features of patent claim 1 and by a conical pulley belt transmission with the features of patent claim 4.

In a link chain designed according to the invention, the individual links are connected by tabs pa chain links formed with several link plates formed as pairs of rocker pressure pieces pushed into recesses of the link plates with rolling surfaces supported on each other, with three chain links arranged adjacent in the circumferential direction of the plate link chain forming a chain link group. The link chain is formed by a large number of chain link groups placed directly next to one another in the direction of rotation, the link plates within a chain link group being arranged point-symmetrically to the center point of the chain link group over the entire width of the link chain.

According to the invention, each chain link group of the link chain has a width of exactly thirty link plates of a predetermined link plate width. The middle chain link of the chain link group with link plates occupies link plate positions on the first link plate position, on the sixth link plate position, on the eighth link plate position, on the eleventh link plate position, on the fourteenth link plate position, on the seventeenth link plate position, on the twentieth link plate position, on the twenty-third link plate position, at the twenty-fifth link plate position and at the thirtieth link plate position. Furthermore, a first chain link arranged immediately adjacent to the middle chain link with link plates occupies link plate positions on the third link plate position, on the fourth link plate position, on the ninth link plate position, on the twelfth link plate position, on the fifteenth link plate position, on the eighteenth link plate position, on the twenty-first link plate position the twenty-fourth link plate position, the twenty-sixth link plate position, and the twenty-ninth link plate position. And finally, a second chain link arranged immediately adjacent to the middle chain link occupies link plates on the link plate positions of the second link plate position, the fifth link plate position, the seventh link plate position, the tenth link plate position, the thirteenth link plate position, the sixteenth link plate position, the nineteenth link plate position, the twenty-second link plate position, the twenty-seventh link plate position and the twenty-eighth link plate position. This has the advantage that the individual link plates as well as the rocker pressure pieces of link chains of different widths are exposed to a significantly reduced load. The plate forces can be distributed very evenly by the construction described above and the load on individual elements can thus be reduced, whereby a longer service life of the plate chain is achieved with the same load (torque transmission). Alternatively, such a modified link chain can also transmit increased torque with an unchanged service life.

First, the individual elements of the claimed subject matter of the invention are explained in the order in which they are mentioned in the set of claims or their meaning, and particularly preferred configurations of the subject matter of the invention are described below.

A link plate is an essential part of a link chain. The link plate is an elongate plate-like plate that has one or more through-openings transverse to its longitudinal extension and the plate surface for passing through and receiving so-called rocker pressure pieces (also referred to as pressure pieces or rocker pieces).

In addition to the link plate, a cradle pressure piece is an essential part of the link chain. The cradle pressure piece forms a so-called cradle joint together with the passage opening of the link plate through which it is guided. Due to the rocker joint design of the link chain, it is possible to realize small running circles on the cone pulleys and thus a high gear spread.

A part or a structural configuration is referred to as a securing element, which serves to ensure that the link plates cannot move laterally axially from the pressure pieces. In the simplest case, the pressure pieces are secured at least at one of their axial ends with a welded piece of wire or the like.

Further advantageous refinements of the invention are specified in the dependently formulated claims. The features listed individually in the dependent claims can be combined with one another in a technologically meaningful manner and can define further refinements of the invention. In addition, the features specified in the claims are specified and explained in more detail in the description, with further preferred configurations of the invention being presented.

According to an advantageous embodiment of the invention, it can be provided that in at least a plurality of immediately adjacent chain link positions transverse to the longitudinal direction of the chain within a chain link of the link chain, the link plates of a chain link are formed by a single link plate for the plurality of chain link positions, so that link plates with a first link plate width and with a second link plate width that differs from the first link plate width are present within a chain link group. In this way, a further optimization of the link chain construction can be achieved with regard to a reduction in the component loads.

According to a further preferred development of the invention, it can also be provided that each chain link group is formed by ten link plates with the smallest link plate width, whereby the effort in terms of assembly and storage of parts can be further optimized.

In addition, the object on which the invention is based is achieved by a continuously adjustable conical pulley belt transmission comprising a first pair of conical pulleys arranged on a first shaft and a second pair of conical pulleys arranged on a second shaft and a link chain arranged for torque transmission between the first pair of conical pulleys and the second pair of conical pulleys, wherein the Plate chain according to the invention, as described above, is formed.

Advantageously, the conical disks of the first pair of conical disks and the conical disks of the second pair of conical disks each have a conical disk angle that is larger than 7° and smaller than 13°, in particular between 9° and 11.5°. This achieves an optimized interaction with the link chain constructed according to the invention.

Furthermore, the invention can also be further developed in such a way that the conical disks of the first pair of conical disks and the conical disks of the second pair of conical disks are made of case-hardened steel called CrMo or CrNiMo, which also allows for a low-wear interaction of the link chain constructed according to the invention with the conical disks of the transmission is beneficial.

According to a further preferred embodiment of the conical pulley belt drive, it can be provided that the conical pulley belt drive with its pairs of conical pulleys is designed to be driven on the input side at a speed of approximately 4000 rpm to 6500 rpm and on the output side at a speed of approximately 12000 rpm. so that an operation is guaranteed within which a wear-reduced operation of the link chain is made possible.

Finally, the invention can also be implemented in an advantageous manner in that the driving conical disk pair is designed to transmit a torque of at least 150 Nm. Advantageously, the cone pulley pair is optimized for a torque range up to a maximum of 460 Nm.

The invention and the technical environment are explained in more detail below with reference to the figures. It should be pointed out that the invention should not be limited by the exemplary embodiments shown. In particular, it should be pointed out that the figures and in particular the proportions shown are only schematic. The same reference symbols designate the same objects, so that explanations from other figures can be used as a supplement if necessary.

• 1 einen Teilausschnitt einer Laschenkette gemäß dem Stand der Technik in einer Perspektivansicht,
• 2 in der oberen Darstellung eine herkömmliche Laschenkette in einem Ausschnitt in einer Draufsicht und in der unteren Darstellung eine Schnittdarstellung längs eines Wiegedruckstücks einer Laschenkette, wobei anhand dieser schematischen Darstellungen der Aufbau und die Bezeichnungen der einzelnen Elemente einer Laschenkette erörtert werden,
• 3 den grundsätzlichen Aufbau einer Kettengliedergruppe in schematischer Darstellung, in einer Draufsicht, wobei in der oberen Darstellung drei vereinzelte Kettenglieder gezeigt sind und in der unteren Darstellung ein Verbund dieser drei Kettenglieder in Form einer aus den drei Kettengliedern bestehenden Kettengliedergruppe,
• 4 eine erfindungsgemäß aufgebaute Laschenkette in einem Teilausschnitt in einer Draufsicht, und
• 5 eine CVT-Getriebeeinheit mit einem Kegelscheibenumschlingungsgetriebe, eingebunden in den Antriebsstrang eines Hybridfahrzeugs in schematischer Darstellung.

Show it:

• 1 a partial section of a link chain according to the prior art in a perspective view,
• 2 in the upper illustration a conventional link chain in a section in a plan view and in the lower illustration a sectional view along a rocker pressure piece of a link chain, with the structure and the designations of the individual elements of a link chain being discussed on the basis of these schematic representations,
• 3 the basic structure of a chain link group in a schematic representation, in a top view, with the upper representation showing three individual chain links and the lower representation showing a combination of these three chain links in the form of a chain link group consisting of the three chain links,
• 4 a link chain constructed according to the invention in a partial detail in a plan view, and
• 5 A schematic representation of a CVT transmission unit with a conical pulley belt transmission, integrated into the drive train of a hybrid vehicle.

1 shows a link chain 1 according to the prior art for a mechanically adjustable continuously variable transmission for a motor vehicle. This link chain 1 comprises a plurality of link plates 2, a plurality of rocker pressure pieces 5 and a plurality of securing elements 50, the rocker pressure pieces 5 for the articulated connection of the link plates 2 transverse to a longitudinal direction direction of the plate-link chain 1 are arranged in recesses 20 of the link plates 2 to form rocker joints 4, and the link plates 2 are arranged secured via the securing elements 50 against axial migration from the rocker pressure pieces 5.

2 shows a conventional link chain 1 in a section in a plan view in the upper representation and a sectional representation along a rocker pressure piece 5 of a rocker joint 4 of a link chain 1 in the lower representation, whereby the structure and the designations of the individual elements of a link chain 1 are clarified on the basis of these schematic representations should be. In the upper illustration it is easy to see how the individual chain links 3; 3-1, 3-2, 3-3 arranged one behind the other within the link chain 1 form individual chain link groups 30 and the same structured chain link groups 30 arranged one behind the other form the link chain 1.

In the illustration below, the arrangement of the individual link plates 2 at corresponding successive link plate positions KLP, from a first link plate position KLP1 to a last link plate position KLPn, over the width B of the link plate assembly can be seen. The width B of the chain link assembly corresponds approximately to the inner distance between two securing elements 50 on the rocker pressure piece 5 shown. The outer chain width b, also shown, corresponds approximately to the axial length of a rocker pressure piece 5 - measured in its center axis.

3 shows the basic structure of a chain link group 30 in a schematic representation, in a plan view. In this case, three isolated chain links 3; 3-1, 3-2, 3-3 and the lower illustration shows a combination of these three chain links 3-1, 3-2, 3-3 in the form of one of the three chain links 3-1, 3-2, 3 -3 existing chain link group 30 shown as part of a link chain 1. The individual chain links 3 are via rocker joints 4 - formed by the two pressure pieces 5 of adjacent chain links 3, which penetrate the openings 20 within the link plates 2 of a chain link 3, linked or connected to one another. A link chain 1 is composed of a large number of chain link groups 30 of the same structure which are arranged one behind the other and are connected to one another. The illustration below shows that the link chain 1 has a plurality of link links 2 over its width (link assembly width) B transversely to the longitudinal extent of the link chain 1 . Each link plate 2 is assigned a link plate position KLP seen over the width B of the link chain 1 - represented here by the link plate positions from the first link plate position "one" KLP1 (below) to the last link plate position "n" KLPn (above).

In the area of the axial ends of the rocker pressure pieces 5, these each have a securing element 50, via which a lateral loss of link plates 2 is prevented.

4 shows a link chain 1 constructed according to the invention in a partial section in a plan view. The plate-link chain 1 shown is designed for a conical pulley belt transmission 100 of a motor vehicle that can be steplessly adjusted in terms of transmission ratio. The individual chain links 3 formed by plate assemblies with several link plates 2 connecting rocker joints 4 are designed as pairs of rocker pressure pieces 5 pushed into recesses 20 of the link plates 2 with rolling surfaces W supported on one another. Every three chain links 3 arranged adjacent to each other in the direction of rotation of the link chain 1 form a chain link group 30, with the link chain 1 being formed by a large number of chain link groups 30 placed directly next to one another in the direction of rotation, and with the link plates 2 within a chain link group 30 over the entire width of the link chain 1 seen point symmetrically to the center point P of the chain link group 30 are arranged.

Each chain link group 30 has a width B of exactly thirty link plates 2 of a predetermined link plate width b1, with the middle chain link 3-2 of the chain link group 30 chain plates 2 of the predetermined link plate width b1 on the link plate positions KLP one KLP1, six KLP6, eight KLP8, eleven KLP11, fourteen KLP14, seventeen KLP17, twenty KLP20, twenty three KLP23, twenty six twenty five KLP25 and thirty KLP30. A first chain link 3-1 arranged adjacent to the middle chain link 3-2 has link plates 2 on the link plate positions KLP three KLP3, four KLP4, nine KLP9, twelve KLP12, fifteen KLP15, eighteen KLP18, twenty-one KLP21, twenty-four KLP24, twenty-six KLP26 and twenty-nine KLP29 on, while a second chain link 3-3 link plates 2 arranged adjacent to the middle chain link 3-2 on the link plate positions KLP two KLP2, five KLP5, seven KLP7, ten KLP10, thirteen KLP13, sixteen KLP16, nineteen KLP19, twenty-two KLP22, twenty-seven KLP27 and twenty-eight KLP28 occupied. Each chain link group 30 is formed by thirty link plates 2 of the same link plate width b1.

5 FIG. 1 shows a CVT transmission unit with a conical pulley belt transmission 100, integrated into the drive train of a hybrid vehicle, in a schematic representation. The conical pulley transmission 100 (also referred to as a variator) comprises a first conical pulley pair 300 with a first conical pulley 301 designed as a fixed pulley and with an axially displaceable second conical pulley 302 designed as a displacement pulley and a second conical pulley pair 500 with a first conical pulley 501 designed as a fixed pulley and an axial slidably arranged as a displacement disk designed second conical disk 502 and the two pairs of conical disks 300; 500 connecting means designed as a link chain 1. The CVT transmission unit also includes an actuator unit AE, by means of which the conical disks 302; 502 of the first and second pair of conical pulleys 300; 500 are axially adjustable in such a way that a desired translation between the first pair of conical disks 300 and the second pair of conical disks 500 can be set. The first pair of conical pulleys 300 can be driven via an electric machine EM and/or an internal combustion engine BKM. In this case, between the internal combustion engine BKM and the driven variator, the electric machine EM is integrated into the drive train via a separating clutch arranged on the internal combustion engine side and a separating clutch arranged on the variator side. The second pair of conical disks 500 is connected to a drive axle of the motor vehicle via a transmission unit. The actuator unit AE is controlled via a control unit that is not shown.

the 5 also shows that the conical disks 301, 302 of the first conical disk pair 300 and the conical disks 501, 502 of the second conical disk pair 500 each have a conical disk angle θ1, θ2. This is advantageously larger than 7° and smaller than 13° and particularly preferably between 9° and 11.5°.

The invention is not limited to the embodiments shown in the figures. The foregoing description is therefore not to be considered as limiting but as illustrative.

Reference List

1

tab chain

2

chain link

20

recess

3

chain link

3-1

first chain link

3-2

second chain link

3-3

third chain link

30

chain link group

4

rocker joint

5

cradle pressure piece

W

rolling surface

50

fuse element

100

Tapered pulley transmission

200

first shaft (cone pulley belt transmission)

300

first pair of pulleys

301

first pulley of the first pair of pulleys

302

second pulley of the first pair of pulleys

400

second shaft (cone pulley belt transmission)

500

second pair of pulleys

501

first pulley of the second pair of pulleys

502

second pulley of the second pair of pulleys

KLP

link plate position

B

Chain plate pack width

b1

link plate width

b2

increased chain plate width

b

chain width

ϑ1, ϑ2

sheave angle

BKM

internal combustion engine

EM

electric machine

AE

actuator unit

P

Center or symmetry point (to point symmetry of the chain link group)

Claims (8)

Plate-link chain (1) for a continuously adjustable conical pulley belt transmission, - its rocker joints (4) connecting the individual chain links (3) formed by plate sets with several chain plates (2) as pairs of rocker pressure pieces (5) pushed into recesses (20) of the chain plates (2) are formed with rolling surfaces (W) that are supported on one another, - with three chain links (3; 3-1, 3-2, 3-3) form a chain link group (30), - the link chain (1) being formed by a large number of chain link groups (30) placed directly next to one another in the direction of rotation, - and the link plates (2) inside of a chain link group (30) viewed over the entire width of the link chain (1) are arranged point-symmetrically to the center point (P) of the chain link group (30), characterized in that -each chain link group (30) has a width (B) of exactly thirty link plates (2 ) has a predetermined link plate width (b1), -- wherein the middle chain link (3-2) of the chain link group (30) has link plates (2) on the link plate positions (KLP) one (KLP1), six (KLP6), eight (KLP8), eleven (KLP11), fourteen (KLP14), seventeen (KLP17), twenty (KLP20), twenty-three (KLP23), twenty-five (KLP25) and thirty (KLP30) -- with a first adjacent to the middle chain link (3-2). Chain link (3-1) chain straps (2) on the chain straps hen positions (KLP) three (KLP3), four (KLP4), nine (KLP9), twelve (KLP12), fifteen (KLP15), eighteen (KLP18), twenty-one (KLP21), twenty-four (KLP24), twenty-six (KLP26) and twenty-nine (KLP29), and -- whereby a second chain link (3-3) adjacent to the middle chain link (3-2) has link plates (2) on the link plate positions (KLP) two (KLP2), five (KLP5), seven (KLP7) , ten (KLP10), thirteen (KLP13), sixteen (KLP16), nineteen (KLP19), twenty-two (KLP22), twenty-seven (KLP27) and twenty-eight (KLP28). Link chain (1) after claim 1 , characterized in that in at least a plurality of immediately adjacent link plate positions (KLP) within a chain link (3, 3-1, 3-2, 3-3) of the plate-link chain (1), the link plates (2) are connected by a single link plate (2) are formed with an increased link plate width (b2), in particular with twice the link plate width (b2). Link chain (1) after claim 1 , characterized in that each chain link group (30) is formed by ten link plates (2) with the smallest link plate width (b1). Continuously variable ratio conical pulley belt transmission (100), comprising a first pair of conical pulleys (300) arranged on a first shaft (200) and a second pair of conical pulleys (500) arranged on a second shaft (400) and one for torque transmission between the first pair of conical pulleys (300) and the link chain (1) arranged in the second pair of conical disks (500), characterized in that the link chain (1) is designed according to one of the preceding claims. Cone pulley belt transmission (100) according to claim 4 , characterized in that the conical disks (301, 302) of the first conical disk pair (300) and the conical disks (501, 502) of the second conical disk pair (500) each have a conical disk angle (ϑ1, ϑ2) that is greater than 7° and smaller than 13° is dimensioned, which is dimensioned in particular between 9° and 11.5°. Cone pulley belt transmission (100) according to claim 4 or 5 , characterized in that the conical disks (301, 302) of the first conical disk pair (300) and the conical disks (501, 502) of the second conical disk pair (500) are made of case-hardened steel with the designation 15CrMo5 or the designation 17CrNiMo6. Cone-pulley transmission (100) according to one of the above Claims 4 - 6 , characterized in that the driving pair of conical pulleys (300) is designed to be driven at a rotational speed of up to a maximum of 12000 rpm, in particular at a rotational speed of up to a maximum of 6500 rpm. Cone-pulley transmission (100) according to one of the above Claims 4 - 7 , characterized in that the driving pulley pair (300) is designed to transmit a torque of at least 150 Nm.

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