DE102020114285B3 - Plate chain with two-part, load-dependent contact between a plate and a rocker pressure piece; as well as continuously variable transmission - Google Patents

Abstract

The invention relates to a plate-link chain (1) for a continuously variable belt transmission (2), with a plurality of plates (3) and several pairs of rocker pressure pieces (5) received in holes (4) of the plates (3), each plate (3) two to one another spaced longitudinal stirrups (6a, 6b) aligned in the direction of pull and two side stirrups (6a, 6b) each connecting the main stirrups (6a, 6b) to one another at one of their ends (7a, 7b) and enclosing the hole (4) together with the main stirrups (6a, 6b) ( 8a, 8b), a rocker pressure piece (9a) forming a first contact point (10) with a first shoulder area (11) on a first trough area (12) formed between a first side bracket (6a) and a first side bracket (8a) ) the tab (3) is supported and a shoulder radius (13) of the first shoulder area (11) is smaller than or equal to a first trough radius (15) of the first trough area (12), with the first shoulder area (11) in a Direction away from the first side bar (6a) is adjoined by a second shoulder area (17), which second shoulder area (17) can be brought into contact with a second trough area (19) adjoining the first trough area (12), forming a second contact point (18) , wherein a second trough radius (16) of the second trough area (19) is matched to a second shoulder radius (14) of the second shoulder area (17) in such a way that the cradle pressure piece (9a) with the tab (3) is only exceeded when a certain value to be transmitted is exceeded Tensile force in the second contact point (18) is in direct contact. The invention also relates to a continuously adjustable belt transmission (2) with this link chain (1).

Description

The invention relates to a link chain for a continuously variable belt transmission, with a plurality of link plates and several pairs of rocker pressure pieces received in holes in the link plates, with each link plate having two spaced-apart longitudinal brackets aligned in the pulling / longitudinal direction and two connecting brackets at one of their ends Has side brackets enclosing the hole together with the side brackets, a (first) rocker pressure piece being supported with the formation of a first contact point with a first shoulder area on a first trough area of the flap formed between a first side bracket and a first side bracket, and a radius of the first shoulder area is smaller or is the same size as a radius of the first trough area. The invention also relates to a continuously adjustable belt drive equipped with this link chain.

Link chains and corresponding belt drives are already well known from the prior art. For example, the DE 10 2016 207 216 A1 a belt and a kit for assembling a belt. Further prior art is from DE 10 2015 112 963 A1 , the DE 30 27 834 A1 , the DE 10 2006 046 600 A1 and the US 2009/0 233 744 A1 known.

Thus, different designs of link plates in link plate chains are already known which, through their contact points, define corresponding contact angles between the rocker pressure piece and the link plate. That contact angle defines the proportions of the introduction of force in the vertical or horizontal direction and thus the proportions of the bending moments in the strap brackets. It has been shown here from the designs known from the prior art that often no defined force vectors can be generated in these contact points or that these force vectors are strongly dependent on tolerance deviations. It is also known to define individual contact radii that ensure a defined force vector, but these solutions have the disadvantage of increased slipping movement in the contact point, which leads to increased wear (pitting).

It is therefore the object of the present invention to provide a plate-link chain, the individual links of which have the lowest possible wear with high tensile loads.

According to the invention, this is achieved in that a second shoulder area adjoins the first shoulder area, in a direction away from the first side bar, which second shoulder area can be brought into contact with a second trough area adjoining the first trough area, forming a second contact point, wherein a radius of the second trough area is matched to a radius of the second shoulder area in such a way that the (first) rocker pressure piece is only in direct contact with the tab when a certain tensile force to be transmitted is exceeded in the second contact point.

Thus, two contact points are made available, of which the first contact point is used for the defined setting of an optimal force vector (while reducing a bending moment) and the second contact point, which comes into contact with the rocker pressure piece with increasing load, is used to form a stop. As a result, a slipping movement between the rocker pressure piece and the bracket and the risk of pitting are significantly reduced.

Further advantageous embodiments are claimed with the subclaims and explained in more detail below.

Accordingly, it is also advantageous if the radius of the second trough area is larger than the radius of the second shoulder area. This releases the radius of the second shoulder area on the rocker pressure piece without load.

In this context, it has been found to be particularly expedient if the radius of the second trough area is 10% to 50% larger than the radius of the second shoulder area.

Furthermore, it is advantageous if the radius of the first shoulder area is larger than the radius of the second shoulder area and a transition between the two radii of the shoulder areas changes continuously. This makes it possible to continuously increase the stop / contact area depending on the load. This reduces the pressure in the contact.

In order to further reduce the pressures, it is also expedient if the radius of the second trough area is larger than the radius of the first trough area and a transition between the two radii of the trough areas changes continuously.

It is also advantageous if the radius of the second trough area widens continuously to a side facing away from the radius of the first trough area. This ensures an exemption and the force is preferably always introduced via the first contact point. this enables manufacturing tolerances to have less influence on the force vector.

Furthermore, it is advantageous if a (first) arc length of the first trough area is equal to a (second) arc length of the first shoulder area. This results in a system that is as defined as possible in the first contact point.

In this context, it is also advantageous if a center of a (first) arc length of the first trough area is equal to a center of a (second) arc length of the first shoulder area.

If a normal running through the center of the first trough area encloses an angle between 58 ° and 70 ° with a longitudinal axis of the tab, as defined as possible, low bending stress causing force vectors are generated at the contact point.

Accordingly, it is also expedient if a normal running through the center of the first trough area also encloses an angle between 58 ° and 70 ° with the longitudinal axis of the bracket.

Furthermore, the invention relates to a continuously variable belt drive for a drive train of a motor vehicle, with a pair of drive pulleys, a pair of driven pulleys and a link chain according to the invention, according to at least one of the previously described embodiments, which operatively connects the pair of drive pulleys and the pair of driven pulleys with one another.

In other words, according to the invention, a two-part, load-dependent contact is implemented between the bracket and the corresponding rocker pressure piece. The contact between the bracket and the rocker pressure piece has a primary contact (first contact point) and thus enables a defined force vector. In order to prevent the slipping movement, stops (secondary radii) are provided in the vertical brackets, which only come into contact with the rocker pressure piece under load (second contact point). With less load and less elastic deformation (almost only primary contacts are effective), an optimal force vector is established. When the load is higher, the rocker pressure piece comes into contact with the stops (secondary radii). However, elastic slip is hindered. This changes the force vector only slightly.

The invention will now be explained in more detail below with reference to figures.

• 1 eine perspektivische Darstellung eines Abschnitts einer erfindungsgemäßen Laschenkette zum Veranschaulichen deren prinzipiellen Aufbaus,
• 2 eine Detaildarstellung eines Kontaktbereiches zwischen einem Wiegedruckstück und einer Lasche zur Ausbildung zweier Kontaktstellen,
• 3 eine Seitenansicht der Lasche und dem Wiegedruckstück der 2, wobei sowohl ein äußerer als auch ein innerer Kontaktbereich zwischen dem Wiegedruckstück und der Lasche ersichtlich sind,
• 4 eine Detaildarstellung des Kontaktbereiches aus 2, wobei ein im Betrieb wirkender Kraftvektor eingezeichnet ist, sowie
• 5 eine vereinfachte Darstellung eines stufenlos verstellbaren Umschlingungsgetriebes aufweisend die erfindungsgemäße Laschenkette.

Show it:

• 1 a perspective view of a section of a link chain according to the invention to illustrate its basic structure,
• 2 a detailed representation of a contact area between a rocker pressure piece and a tab to form two contact points,
• 3 a side view of the tab and the rocker pressure piece of 2 , whereby both an outer and an inner contact area between the rocker pressure piece and the tab can be seen,
• 4th a detailed representation of the contact area 2 , with a force vector acting during operation being drawn in, as well as
• 5 a simplified representation of an infinitely variable belt transmission having the link chain according to the invention.

The figures are merely of a schematic nature and are used exclusively for understanding the invention. The same elements are provided with the same reference symbols.

A link chain according to the invention 1 is in 1 clearly visible. The plate chain 1 has a large number of tabs 3 on, each via rocker pin pairs 5 with adjacent tabs 3 are coupled. Every tab 3 has a hole 4th on, each to one axial end of the tab 3 towards the inclusion of a rocker pressure piece pair 5 is trained. Each cradle pressure piece pair 5 has two rocker plungers in the usual way 9a , 9b on, which rest against one another tiltably along a rolling path.

A preferred area of application for the plate link chain 1 is associated with 5 indicated, in which a continuously adjustable belt drive 2 is shown schematically. The plate chain 1 is in this version between a pair of drive pulleys 26th as well as a pair of output disks 27 of the belt drive 2 used effectively.

With 3 is a tab 3 together with a first rocker pressure piece 9a of the rocker pressure piece pair 5 shown. The tab 3 has two longitudinally / along its longitudinal axis 25th running, spaced-apart temple bars 6a , 6b as well as two transverse side brackets 8a , 8b on. At one axial end each 7a respectively. 7b the temple bow 6a , 6b are the side stirrups 6a , 6b via a first or a second side bracket 8a , 8b connected with each other. The side and side brackets 6a , 6b , 8a , 8b enclose the hole 4th , each with a side bracket 8a , 8b down in the assembled Condition of the link chain 1 a cradle pressure piece pair 5 records.

With 3 is exemplarily that (first) contact area between a first rocker pressure piece 9a and the first bow stirrup 6a towards a first side bracket 8a shown, these embodiments of course also for a further (second) contact area between the same first rocker pressure piece 9a and the second bow stirrup 6b towards the first side bracket 8a are valid. Furthermore, the two (first and second) contact areas are also between the first rocker pressure piece 9a of the other pair of rocker pressure pieces 5 on the part of the second side bracket 8b implemented in this way.

The one with the 2 and 4th The contact area shown in more detail has two along an inner circumference 28 the tab 3 offset contact points 10 , 18th on. The following consideration of the formation of the two contact points 10 , 18th thus takes place in a plane of extent of the tab 3 the extent to which the through hole is located 4th runs vertically. A first point of contact 10 is between a first shoulder area 11 of the first rocker pressure piece 9a and a first well area 12th (in the transition area between the first side stirrup 6a and the first side bracket 8a ) the tab 3 educated. The shoulder area 11 and the trough area 12th the first point of contact 10 have the same radius in this embodiment, the respective radius being constant over a certain arc length. The radius of the first shoulder area 11 is the first shoulder radius 13th marked, whereas the radius of the first trough area 12th as the first bowl radius 15th is marked.

As an alternative to the same implementation of the first shoulder radius 13th and the first bowl radius 15th According to further statements, it is also advantageous if the first shoulder radius 13th smaller than the first bowl radius 15th is.

With 2 also shows that a middle 23 the arc length of the first shoulder area 11 and a middle 22nd the arc length of the first trough area 12th on a common normal 24 lie. The normal 24 runs normal to the inner circumference 28 . Those normal ones 24 is thus directly through the middle 22nd , 23 the arc lengths of the shoulder area running in the circumferential direction 11 and the well area12. It can be seen here that the normal 24 with a longitudinal axis 25th the tab 3 encloses an angle α. This angle α is preferably chosen between 58 ° and 70 °.

By training the first point of contact 10 on the two contact areas for each rocker pressure piece 9a it comes in the usual way between the first rocker pressure piece 9a and the tab 3 in operation to a form-fitting system.

According to the invention, there is now a second contact point 18th following the first contact point 10 intended. This second point of contact 18th is along the inner circumference 28 seen on the first side bracket 8a facing side of the first contact point 10 arranged, which is designed in principle such that there the tab 3 and the first rocker pressure piece 9a only come into direct contact when a tensile force to be transmitted exceeds a minimum value.

The second point of contact 18th is between a further second shoulder area 17th , which is in the circumferential direction of the tab 3 seen directly on the first shoulder area 11 adjoins, and a second trough area 19th formed, which second trough area 19th in the circumferential direction directly to the first trough area 12th connected, trained. The second well area 19th is already the side bracket 8a assigned.

The second shoulder area 17th and the second well area 19th are also each rounded with a radius over a certain arc length. A (second) shoulder radius 14th of the second shoulder area 17th is chosen to be smaller than the first shoulder radius 13th . In addition, the second trough radius is 16 of the second well area 19th larger than the second shoulder radius 14th . In this regard, it has been found to be particularly useful if the second trough radius 16 10% to 50% larger than the second shoulder radius 14th is. It is also advantageous if the second bowl radius 16 larger than the first bowl radius 15th is.

On the part of the first rocker pressure piece 9a it can also be seen that a (first) transition 20th between the two shoulder areas 11 , 17th runs continuously. Accordingly, the radius increases at the transition 20th between the first shoulder area 11 and the second shoulder area 17th of the first rocker pressure piece 9a continuously up to the second shoulder radius 14th there.

Accordingly, it also changes at a second transition 21 between the first well area 12th and the second well area 19th the radius is continuous.

It can also be seen that to one of the first trough area 12th remote side of the circumference of the second trough area 19th , this second trough area 19th continuously expanded.

In other words, contacts are in accordance with the invention 10 between tab 3 and rocker pressure piece 9a implemented, which each form primary contacts that enable a defined force vector. There are second contact points to prevent the slipping movement 18th (Stops, secondary radii) in the vertical side brackets 8a , 8b present, which only come into contact with the rocker pressure piece under load 9a come. With low load and low elastic deformation (almost only primary contacts 10 effective) an optimal force vector is established. With a higher load, however, the rocker pressure piece comes 9a with the second contact points (stops, secondary radii) 18 in contact. This hinders elastic slippage. This changes the force vector only slightly.

List of reference symbols

1

Plate chain

2

transmission

3rd

Tab

4th

hole

5

Cradle pressure piece pair

6a

first single bow

6b

second single bow

7a

first end

7b

second end

8a

first side bracket

8b

second side bracket

9a

first rocker pressure piece

9b

second rocker pressure piece

10

first point of contact

11

first shoulder area

12th

first trough area

13th

first shoulder radius

14th

second shoulder radius

15th

first bowl radius

16

second bowl radius

17th

second shoulder area

18th

second contact point

19th

second trough area

20th

first transition

21

second transition

22nd

first middle

23

second middle

24

Normal

25th

Longitudinal axis

26th

Drive pulley pair

27

Output pulley pair

28

Inner circumference

Claims (10)

Plate chain (1) for a continuously variable belt drive (2), with a plurality of plates (3) and several pairs of rocker pressure pieces (5) received in holes (4) of the plates (3), each plate (3) being two spaced apart in the pulling direction aligned longitudinal stirrups (6a, 6b) and two side stirrups (8a, 8b) which connect the longitudinal stirrups (6a, 6b) to one another at one of their ends (7a, 7b) and which surround the hole (4) together with the longitudinal stirrups (6a, 6b) having a rocker pressure piece (9a) forming a first contact point (10) with a first shoulder area (11) on a first trough area (12) of the tab (12) formed between a first side bracket (6a) and a first side bracket (8a). 3) is supported and a first shoulder radius (13) of the first shoulder area (11) is less than or equal to a first trough radius (15) of the first trough area (12), characterized in that on the first shoulder area (11), in a Direction away v A second shoulder area (17) adjoins the first side bar (6a), which second shoulder area (17) can be brought into contact with a second trough area (19) adjoining the first trough area (12), forming a second contact point (18) is, wherein a second trough radius (16) of the second trough area (19) is matched to a second shoulder radius (14) of the second shoulder area (17) in such a way that the rocker pressure piece (9a) with the tab (3) only when a certain one is exceeded transmitting tensile force in the second contact point (18) is in direct contact. Link chain (1) Claim 1 , characterized in that the second bowl radius (16) of the second bowl region (19) is greater than the second shoulder radius (14) of the second shoulder region (17). Link chain (1) Claim 1 or 2 , characterized in that the second bowl radius (16) of the second bowl region (19) is 10% to 50% larger than the second shoulder radius (14) of the second shoulder region (17). Link chain (1) after one of the Claims 1 until 3 , characterized in that the first shoulder radius (13) of the first shoulder area (11) is larger than the second shoulder radius (14) of the second shoulder area (17) and a transition (20) between the two shoulder radii (13, 14) of the shoulder areas ( 11, 17) changes continuously. Link chain (1) after one of the Claims 1 until 4th , characterized in that the second bowl radius (16) of the second bowl region (19) is greater than the first bowl radius (15) of the first bowl region (12) and a transition (21) between the two bowl radii (15, 16) of the bowl regions ( 12, 19) changes continuously and / or the second trough radius (16) of the second trough area (19) continuously widens to a side facing away from the first trough radius (15) of the first trough area (12). Link chain (1) after one of the Claims 1 until 5 , characterized in that an arc length of the first trough area (12) is equal to an arc length of the first shoulder area (11). Link chain (1) after one of the Claims 1 until 6th , characterized in that a center (22) of an arc length of the first trough area (12) is equal to a center (23) of an arc length of the first shoulder area (11). Link chain (1) Claim 7 , characterized in that a normal (24) running through the center (22) of the first trough area (12) encloses an angle (a) between 58 ° and 70 ° with a longitudinal axis (25) of the tab (3) running in the longitudinal direction. Link chain (1) Claim 7 or 8th , characterized in that a normal (24) running through the center (23) of the first trough area (12) encloses an angle (α) between 58 ° and 70 ° with the longitudinal axis (25) of the tab (3). Infinitely variable belt transmission (2) for a drive train of a motor vehicle, with a drive pulley pair (26), a driven pulley pair (27) and a link chain (1) according to one of the Claims 1 until 9 .

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