WO2010051801A1

WO2010051801A1 - Hydrodynamic torque converter having torque converter lock-up clutch

Info

Publication number: WO2010051801A1
Application number: PCT/DE2009/001551
Authority: WO
Inventors: Toros GÜLLÜK; Peter Droll; Bruno MÜLLER
Original assignee: Luk Lamellen Und Kupplungsbau Beteiligungs Kg
Priority date: 2008-11-10
Filing date: 2009-11-03
Publication date: 2010-05-14
Also published as: DE102009051723A1; DE112009002560B4; DE112009002560A5

Abstract

The invention relates to a hydrodynamic torque converter (1) comprising a housing (2), said torque converter being arranged concentrically around a hub (10) and rotationally fixed thereto. In said torque converter, a pump wheel, a turbine wheel, a stator, and a converter lock-up clutch (4) having a disk pack (6) are arranged. The disk pack (6) has at least one friction surface, which can engage in a counter friction surface in an end disk (6b), wherein the friction surfaces are provided with cooling grooves. The converter lock-up clutch (4) comprises a piston (5) composed of two partial pistons (5a, 5b), wherein the piston (5) becomes an additional friction element when the disk pack (6) is pressurized by way of the face of the partial piston (5b). According to the invention, the cooling oil used for cooling the friction elements (5b) of the converter lock-up clutch and circulated by the torque converter (1) is automatically and completely conducted through the piston (5) and the cooling grooves of the disk pack (6).

Description

Hydrodynamic torque converter with lock-up clutch

The invention relates to a hydrodynamic torque converter with lockup clutch having the features of the preamble of claim 1.

Hydrodynamic torque converters with friction ring or friction lining as well as with such equipped wet-running clutches have become known from US 4,969,543 and US 5,056,631. Since the oil in known hydrodynamic torque converters from the external converter cooling circuit is not guided deliberately over the converter lock-up clutch to be cooled, hydrodynamic flow converters with a lock-up clutch are described in these two US patents, in which the engaged friction surfaces are designed such that also when the lock-up clutch is closed, an oil flow between the chambers provided on both sides of an annular piston is made possible. These hydrodynamic flow transducers have a housing in which a pump impeller, a turbine wheel, a stator and the lock-up clutch, which has the annular piston, are accommodated. On both sides of the ring piston oil-filled chambers are provided. The first of the chambers is formed radially within the friction surfaces of the lock-up clutch and limited by the annular piston and a radial wall of the housing, while in the second chamber, at least the turbine wheel is arranged. The oil flow serves to reduce the thermal load of the components occurring as a result of slippage in the lockup clutch, in particular in the area of the friction lining or the friction surfaces.

Further, solutions are known which seek to guide the oil by eliminating all possible flow paths of the cooling oil, except those paths which pass over the lockup clutch, through guide plates and sealing elements (eg, Belleville springs between adjacent parts rotating at the same speed ) is provided with a high flow resistance, so that the flow of cooling oil through the transducer substantially leads to the converter lockup clutch and in combination with Nutmustern having a self-promotion effect, the cooling oil is at least partially supported by the cooling grooves. This principle is described in DE 103 50 935 A1. In this solution can be optimized by appropriate measures the flow of oil through the fins of a torque converter lockup clutch. For this purpose, the flow resistance for the oil is increased in the area that is far from the converter lock-up clutch. With a second, independent measure, however, the flow resistance for the oil is reduced via the torque converter lock-up clutch. WO 2007/079713 shows a solution for a forced oil flow converter. In this case, the oil drain is selectively directed only via the converter lockup clutch by an attached on the side of the piston additional wall is applied to the piston, which is the disk pack and thus facing away from the pressure chamber for the piston. The end of this additional wall, which is arranged near the disk pack, is applied essentially oil-tight on the surface of the adjacent disk. The other end of the additional wall, which is close to the transmission input shaft, is rotatable and in turn connected to it in an oil-tight manner.

In addition, according to WO 2007/048505 A1, it is known to remove the oil for cooling the converter lockup clutch from the pressure space between piston and converter housing by providing a bore in the clutch piston through which the oil can flow or by causing a leakage at the seal in the outer diameter range the piston is made specifically for cooling. However, this production of a processable defined leakage is very difficult, since a leak very tolerance, wear and the degree of contamination of the oil used is dependent and can not be reliably maintained over the entire life. In addition, the use of the pressurized oil for firing the clutch to cool the lockup clutch from a 3-channel converter principle makes a 2-channel converter principle and the cooling flow can not be controlled independently of the clutch closing pressure. In addition, at low torque and high slip speeds, not enough cooling flow is conducted through the torque converter lock-up clutch.

However, in order to save parts and to realize a leaner coupling concept, the clutch piston used to close the torque converter lockup clutch serves as a friction partner, on the rear side of which a heat accumulation in the oil is caused, especially in a torque converter lockup clutch with one or two friction plates (twin plate) However, this may adversely affect the oil, since the oil is not replaced behind the piston. The consequence of this is a continuous heating, whereby critical oil-damaging temperatures are reached, which can cause a change in the coefficient of friction characteristic and thus form the basis for a judder of the clutch.

Therefore, the object of the invention is to provide a hydrodynamic torque converter with a lockup clutch, in which by an improved cooling of the lockup clutch the generated by the friction loss power ma ximalen temperatures are reduced at the friction surfaces of a clutch, thereby extending the life of the oil and the friction linings of the clutch.

This object is achieved with a hydrodynamic torque converter with a lock-up clutch having the features of claim 1.

Thereafter, the surrounded by a housing hydrodynamic torque converter is arranged concentrically around a hub and rotatably connected thereto. In this a pump impeller, a turbine wheel, a stator and a lockup clutch with a disc pack are arranged. The disk pack has at least one friction surface which can be brought into engagement with a counter friction surface in an end disk. The friction surfaces are usually provided with cooling grooves. Next, the torque converter lock-up clutch has a piston composed of two pistons, which is the additional friction partner under pressure of the disk set on the face of its piston part, serving for cooling the friction partner of the converter lockup clutch, circulated through the torque converter cooling oil, forcibly and completely by the piston and the cooling grooves of the disk set is passed.

In an advantageous embodiment of the torque converter, the point of introduction of the oil, starting from the piston, in the disk set is freely selectable. The same applies to the point of discharge of the oil from the disk pack.

In addition, it is advantageous that the partial piston facing the converter lockup clutch has at least one recess in the region of this converter lockup clutch. Also, a plurality of recesses may be arranged distributed over the circumference of this partial piston.

In order to produce a connection through the disk pack, it is particularly advantageous if the at least one disk is provided with at least one recess. However, a plurality of recesses may be arranged distributed over the circumference of the annular surface of the lamella, which are either arranged on the same diameter or can also be spaced apart radially. - A -

Furthermore, it is advantageous for the formation of a space that the two partial pistons are connected to one another via at least one connection point, which is preferably located at or in the vicinity of the outer diameter of at least one of the partial pistons.

However, a connection formed as an annular curvature sealing connect the facing annular surfaces of the partial piston with each other. However, the connection between the two partial pistons can also not be sealing, but be designed so that a channel stops in the radial direction.

In a further advantageous embodiment of the invention, the disk set of the lockup clutch consists of at least one blade and an end plate. This design of the torque converter lockup clutch is sufficient to realize the positively driven oil flow according to the invention. If more axial space is available, several lamellae and one end lamella can be joined together to form a lamella package. Important for the realization of a coupling function, however, is that both the at least one lamella to the respectively adjacent lamella or to the end lamella and the end lamella again to the immediately adjacent lam has friction linings, which are traversed by cooling grooves. To ensure the discharge of the oil from the disk pack, it is either necessary that the outlet of the oil from the at least one lamella takes place in the amount of the outer or inner diameter of the end plate or the end plate has at least one recess. As with the at least one lamella, several recesses may also be distributed over the circumference of the annular surface of the end lamella.

In a further embodiment, the at least one lamella can be provided with at least one recess. Advantageously, a plurality of recesses distributed over the circumference of the annular surface of the lamella are arranged on the same diameter or radially spaced from each other.

To form a channel in the disk set, it is particularly advantageous that the ends of the at least one lamella and the respective free end of the end lamella are spaced from the opposite component surface.

In a further particularly advantageous embodiment of the invention, the path of the oil flow through the lockup clutch in the radial direction by accordingly delimited between the friction surfaces bearing parts of the lockup clutch and the plate pack used Belagdichtringe or pad sealing lips.

Through the formation of channels, by producing recesses in the respective components or by introducing sealing points between axially adjacent components, the path of the cooling oil from the piston via the torque converter lockup clutch is predetermined and thus forcibly guided oil flow, so that achieves optimum cooling of the oil becomes.

The invention will be explained in more detail with reference to an embodiment and associated drawings.

Show it:

Fig. 1a is a partial sectional view of a closed piston according to the invention

(Sandwich piston) a converter lockup clutch with central oil supply and "open" end plate,

1b is a partial sectional view of a closed sandwich piston a converter lockup clutch with central oil supply and "open" end plate,

Fig. 2 is a partial sectional view of a closed sandwich piston of FIG.

1b, with a pad sealing ring arrangement for the sealing of the oil supply in a first variant,

Fig. 3 is a partial sectional view of a closed sandwich piston of FIG.

1 b with a further variant of the pad sealing ring arrangement for sealing the oil supply,

4 is a partial sectional view of a closed sandwich piston of a lockup clutch with further structural design for an oil supply, 5 is a partial sectional view of an open sandwich piston of a converter bridging clutch with a pad sealing ring arrangement as in FIG. 2 and "open" end plate,

6 is a partial sectional view of an open sandwich piston of a converter bridging clutch with an oil supply as in FIG. 4 and the end plate closed, FIG.

7a and 7b is a partial sectional view of a closed sandwich piston of a converter lerüberbrückungskupplung with each alternating direction of Ölzu drove through the friction linings of the converter lockup clutch,

8 is a partial sectional view of a closed sandwich piston of a converter lockup clutch with an outer disk carrier as a further constructive possibility for the rotationally fixed connection of the end plate and possibly further outer plates each with the drive and the sealing of the oil supply,

8a is an enlarged view of a detail of FIG. 8, the area of the

Sealing of the oil supply shows.

Figures 1 to 8 show a partial section of a lockup clutch 4 of a torque converter 1 with a housing 2, wherein the designation of the same components is maintained in all figures. This converter lock-up clutch 4 consists essentially of a piston 5, which is joined together by means of two mutually connected part pistons 5a and 5b to form a so-called "sandwich piston" and is arranged concentrically on a hub 10 with a rotation axis 3, with which it is firmly connected the partial piston 5a in relation to the converter lock-up clutch 4, the outer partial piston and the partial piston 5b corresponding to the inner partial piston.Further, this piston 5 is operatively connected to the plate pack 6 of the torque converter lock-up clutch 4, which in this embodiment a blade 6a connected to a plate carrier 7 and also is concentrically arranged around the hub 10. The plate pack 6 further comprises an end plate 6b which is pressed into the housing 2 in this and in Figure 1b The end faces of the plates 6a and 6b are provided with a friction lining and 1b and the following figures ren is the slat 6a on both sides, the end plate 6b in contrast, on one side, provided with a friction lining, which faces the blade 6a. This respective friction lining has depressions that follow, for example, a pattern. In this way, a positive guidance of an oil flow is generated by cooling grooves, which is necessary for the cooling of the friction partners and thus both the piston 5 and the fins 6a, 6b.

Further, this torque converter 1 on the drive side rotatably connected to a driving plate 12. Starting from this basic structure, in the figures 1a and 1b, both sub-pistons 5a and 5b connected to each other at the outer periphery, that by this connection a circumferential groove is formed, into which a seal in the form of a sealing element 11 for sealing the piston 5 against the wall of the housing 2 is introduced. In addition, it is apparent from these two figures that both in the sub-piston 5b and in the blade 6a a plurality of circumferentially distributed recesses 9a and 9b are provided in the form of, for example, bores, which are preferably arranged on the same diameter, wherein the recesses in the sub-piston 5b with 9a and the recesses in the blade 6a are denoted by 9b. Preferably, the recesses 9a in the piston 5 are arranged in this embodiment on the same diameter as that of the recesses 9b of the blade 6a, so that over its length in each case a channel is formed. In these figures, these recesses 9a and 9b are preferably arranged on an average diameter and in the region of the disk carrier 7 of the disk 6a.

In Figure 1a, in which the piston 5 is not yet applied to the disk set 6 with pressure, the path of the oil flow for cooling the friction partner is indicated by arrows. It can be seen that the external oil for cooling the lockup clutch 4 exits through a radial bore 13 in the hub 10. From this it passes into the intermediate space of the double-walled sandwich piston 5, flows through it in the direction of lockup clutch 4, passes through the recesses 9a, 9b, flows through the cooling grooves of the friction linings of lamella 6a and end fin 6b and also flows around the inner diameter of both the lamella 6a also by the annular recess 15 formed by the inner diameter of the end plate 6b to the adjacent plate carrier in order ultimately to pass through corresponding recesses 14 in the lining carrier 7 and recesses 16 in the end plate 6b in the transducer space 17.

In this way, the oil, starting from the hub 10, is heated via the converter lock-up clutch 4. It can then cool in the transducer space 16. In Figure 1b, the flow is blocked for the oil by the piston 5, the plate pack 6 is pressurized and thus closes the entry of the oil to the converter chamber 17 through the recesses 9a. Thus, no oil can reach neither the recesses 9b nor the remaining recesses 14, 15 and 16.

In contrast to FIGS. 1a and 1b, in FIG. 2 the disk pack 6 and thus in each case each disk 6a and 6b is provided on the inner diameter with a pad sealing ring 18 which seals the gap between the disks 6a, 6b in the direction of the hub 10. Otherwise, in this figure by means of the arrow, the path of the oil is shown from the entry into the interspace of the sandwich piston 5 via the recesses 9a of the converter lockup clutch 4 with its disk pack 6. Since the disk pack 6 is sealed in the direction of the hub 10, the positively driven oil can only pass through the recesses 16 in the end disk 6b into the converter space 17 and cool down there.

In Figure 3, the lockup clutch 4, as in Figure 2, closed. In this embodiment, the recesses 9a of the sub-piston 5b are again arranged congruent with the provided in the blade 6a of the lockup clutch 4 recesses 9b. In addition, in contrast to Figure 2, the plate pack 6 of the lockup clutch 4 is sealed in the region of the circumference of the blade 6a. This is in each case in the u. a. arranged by the thickness of the friction linings predetermined spaces between the slats 6a and 6b a pad seal 18. Thus, the oil flow passes in accordance with the direction of the arrow in this case via the hub 10 first into the intermediate space between the two sub-pistons 5a and 5b of the sandwich piston 5, flows through the recesses 9a and 9b of sub-piston 5b or lamella 6a to the cooling grooves of the friction linings of Lamella packages 6 over the inner diameter of both through the recesses 14 in the lining carrier as well as through the formed on the inner diameter of the end plate 6b to the lining carrier 7 annular recess 15 finally into the transducer space 17.

Further possibilities of specifying the oil path are shown in the following figures 4 to 8, which shows the lockup clutch 4 each in the closed state. Thus, for example, according to FIG. 4, the possibility of specifying the oil path is that the recesses 9a of the sub piston 5b are displaced outwards to such an extent that the inner diameter of these recesses 9a is greater than the outer diameter of the blade 6a or coincides therewith. In addition, the inner diameter of the blade 6a is selected so that it ends in the recesses 14 of the disk carrier 7. In order to can the oil located in the intermediate space of the sandwich piston 5, starting from the recesses 9a in the sub-piston 5b on the outer diameter of the blade 6a, from there via the cooling grooves of the friction linings of the disk set 6, on the one hand via the annular recess formed in the end region of the inner diameter of the end plate 6b 15 and on the other hand via the provided in the plate carrier 7 recesses 14 flow into the converter space 17.

In contrast to the described Figures 1 to 4, Figure 5 shows another possible design of the sandwich piston 5, which is open at the outer diameter. In this piston 5, the sub-piston 5a is cup-shaped in its end and so bulges to the sub-piston 5b, that this with its encircling bulge 19 (or more bulges 19 on the same or different diameter) sealingly abuts the flat end surface of the piston part 5b. In this way, the actual connection between the two pistons 5a and 5b is made. Just as well, the curvature 19 can be generated by the sub-piston 5b. By this curvature / s 19 a more uniform surface pressure distribution is generated at the friction surfaces of the friction partners. In addition, in this embodiment, the outer diameter of the partial piston 5b is preferably the same size with the lamella 6a, so that between the wall of the cup-shaped end of the partial piston 5a and the lateral surfaces of the partial piston 5b and lamella 6a, a circumferential channel 20 is formed in the in this area provided recesses 16 of the caulked with the housing 2 end plate 6b opens. Next, a channel is formed from the recesses 9a and 9b, which are introduced radially within the circumferential seal of both partial pistons 5a and 5b due to the curvature 19. In addition, in turn provide in this channel towards the hub 10 introduced Belagdichtringe 18 for a radial seal in this direction. As a result of the seal produced between the two partial pistons 5 a and 5 b in the region of the end face of the partial piston 5 b in the form of the circumferential curvature 19 or piston nose, the oil located in the interspace of the sandwich piston 5 is forced into the plate set in the channel formed by the recesses 9 a and 9 b 6, as indicated by the arrow. The oil can emerge in the outer diameter region of the friction linings of the lamellae 6a and 6b, whereby the cooling grooves flow through, in order finally to reach the converter space 17 via the recess 16 in the region of the outer diameter of the end lamella 6b.

FIG. 6 shows a further embodiment of the sandwich piston 5, which, as in FIG. 5, is open at the outer end. Likewise, its partial piston 5a, as in FIG. 5, has an annular curvature 19 in the form of a piston nose, which has a specific diameter range in order to form a pressure surface for a clutch closing force introduction. These However, compared to Figure 5 at least in the radial direction is designed so that with respect to the partial piston 5b, a channel is formed. As in the previous figures, the end plate 6b is fixedly connected to the converter housing 2. Otherwise, the oil is further forced according to the arrows as shown in Figure 4, wherein the flow of oil is deflected so that it flows through the cooling grooves of the friction linings radially inwardly. After flowing through the Lameilenpaketes 6, the oil in turn passes into the converter space 17th

FIG. 7a, which shows a similar construction of the lock-up clutch 4 as in FIG. 2, differs therefrom in that the positions of the recesses 9a in the sub-piston 5b do not coincide with the positions of the recesses 9b in the blade 6a, so that through the lining gaskets 18 on the outer and inner diameter of the blade 6a between Lamelleδa and part piston 5b on the one hand and the pad seal on the inner diameter of the slats 6b between the slats 6a and 6b on the other hand, a diversion of the oil within the disk pack 6 is achieved by 180 ° to the adjacent friction linings. By this deflection of the flow resistance is increased for the oil, whereby the residence time of the oil in the disk pack 6 is extended and the oil flow longer has the opportunity to dissipate heat from this claimed area of the friction partners and thus the friction surfaces bearing parts, whereby the heat of The friction partners can be better absorbed by the oil and transported away from them.

In Figure 7b, a deflection of the oil by 180 ° relative to adjacent friction linings is also achieved by a different positioning of the recesses 9a and 9b, as can be seen in the direction of the arrows. Otherwise, the structure of this hydrodynamic torque converter 1 with lockup clutch 4 is the same as that described in FIG.

In Figure 8, a deflection of the oil is also indicated by 180 ° in the lockup clutch 4 on the basis of the arrow, which differs from the preceding figures 1 to 7 in that in this embodiment, the lockup clutch 4 has an outer plate carrier 8, against which the sandwich piston 5 is circumferentially sealed and thus does not abut the converter housing 2. Otherwise, the structure of this converter 1 is analogous to that in Figure 7b.

FIG. 8 a shows the detail from FIG. 8 in an enlargement, so that the forced guidance of the oil, represented by the arrow course, through the cooling grooves of the friction linings of the converter lock-up clutch 4 is clearly visible. In addition, the spaces of the lamella 6a to the adjacent components 5b, 6b are clearly visible in this figure.

By virtue of this cooling oil flow path forcibly guided in FIGS. 1 to 8 described above, the cooling of the friction partners of the converter lockup clutch 4 is optimized. A self-conveying effect by the groove pattern in the friction linings by the drag effect or radial pumping action of the oil in the rotating cooling grooves, as used in the prior art, is not required in these embodiments.

If the cooling oil flow in the region of the inner diameter region of the friction / n initiated, as in Figures 1a, 2 and 5, flows due to the low flow resistance of the cooling oil flow in the effective direction of centrifugal force through the cooling grooves of the lockup clutch 4. However, as in Figures 3, 4, 7b and 8, the cooling oil flow can also be introduced selectively into the diameter range with the largest surface pressure in order to specifically reduce the maximum friction surface temperature in this region.

In all structural embodiments, both the point of initiation of the clutch closing force and that of the cooling oil in the lockup clutch 4 can be selected as needed. The former, to achieve a uniform surface pressure, the latter to flow through the point with the largest surface pressure with the cooler oil first.

LIST OF REFERENCES

Torque converter / converter

converter housing

axis of rotation

Converter lockup clutch

Piston / sandwich piston a outer part piston b inner part piston

Disc pack a Slat b End disc

Inner plate carrier

Outer plate carrier a recess b recess 0 hub 1 seal / sealing element 2 driving plate 3 bore 4 recess 5 passage / channel 6 recess 7 transducer chamber 8 pad seal 9 buckle 0 channel

Claims

claims

1. Hydrodynamic torque converter (1) with a housing (2), which is arranged concentrically around a hub (10) and connected to this non-rotatably, in which a pump, a turbine wheel, a stator and a lockup clutch (4) with a disk pack ( 6) are arranged, and the disk set (6) has at least one friction surface which is engageable with a counter friction in an end plate (6b), wherein the friction surfaces are provided with cooling grooves, and the lockup clutch (4) one of two part pistons ( 5a, 5b) has a composite piston (5), and the piston (5) upon pressurization of the disk set (6) via the end face of its partial piston (5b) for additional friction partner, characterized in that for cooling the friction partners of the lockup clutch (4 ), via the torque converter (1) circulated cooling oil, forcibly and completely by the piston (5) and the cooling grooves of the disk pack (6) is passed.

2. Hydrodynamic torque converter (1) according to claim 1, characterized in that the point of introduction of the oil, starting from the piston (5), in the disk set (6) is freely selectable.

3. Hydrodynamic torque converter (1) according to claim 1, characterized in that the point of the discharge of the oil from the disk pack (6) is freely selectable.

4. hydrodynamic torque converter (1) according to claim 1, characterized in that the converter lock-up clutch (4) facing the partial piston (5b) in the region of this converter lock-up clutch (4) has at least one recess (9a).

5. Hydrodynamic torque converter (1) according to claim 4, characterized in that over the circumference of the annular part piston (5b) a plurality of recesses are arranged.

6. Hydrodynamic torque converter (1) according to claim 1, characterized in that the partial pistons (5a, 5b) are connected to each other at least via a connection point.

7. Hydrodynamic torque converter (1) according to claim 6, characterized in that the connection point is located at or in the vicinity of the outer diameter of at least one of the partial pistons (5a, 5b).

8. A hydrodynamic torque converter (1) according to claim 6, characterized in that as a ring-shaped curvature (19) formed connection point, the facing annular surfaces of the partial piston (5a, 5b) sealingly interconnects.

9. Hydrodynamic torque converter (1) according to claim 8, characterized in that the annular curvature (19) has at least one channel for the oil flow in the radial direction.

10. Hydrodynamic torque converter (1) according to claim 1, characterized in that the disk set (6) of the lockup clutch (4) consists of at least one blade (6a) and an end plate (6b).