Dual clutch device and drive unit equipped with it

Abstract

A dual-clutch device (10) for an electric axle drive device of a motor vehicle, comprising a first hydraulically actuated multi-plate clutch (12a) and a second hydraulically actuated multi-plate clutch (12b) arranged axially adjacent to the first multi-plate clutch (12a), wherein a first actuating piston (28a) with a first pressure chamber (30a) and a second actuating piston (28b) with a second pressure chamber (30b) are arranged axially between the multi-plate clutches (12a, 12b), wherein a first centrifugal oil chamber (34a) for the first pressure chamber (30a) and a second centrifugal oil chamber (34b) for the second pressure chamber (30b) are provided, is characterized in that the first actuating piston (28a) with the first pressure chamber (30a) and at least a first pressure oil supply channel (33a) and the first centrifugal oil chamber (34a) and at least a first centrifugal oil supply channel (36a) of the first centrifugal oil chamber (34a) on the one hand,and the second actuating piston (28b) with the second pressure chamber (30b) and at least one second pressure oil supply channel (33b), and the second centrifugal oil chamber (34b) and at least one second centrifugal oil supply channel (36b) for the second centrifugal oil chamber (34b), on the other hand, each have the same dimensions. Identical feed channels result in a 50 / 50 split of the centrifugal oil flow, leading to a synchronous response of the two clutches. Short lines, thanks to the inventive design with the actuating devices located centrally between the clutch plates, further improve the clutch response.

Description

[0001] The invention relates to a dual-clutch device for an electric axle drive device of a motor vehicle, comprising a first hydraulically actuated multi-plate clutch and a second hydraulically actuated multi-plate clutch arranged axially next to the first multi-plate clutch. A first actuating piston having a first pressure chamber and a second actuating piston having a second pressure chamber are arranged axially between the multi-plate clutches. A first centrifugal oil chamber is provided for the first pressure chamber and a second centrifugal oil chamber is provided for the second pressure chamber. The invention further relates to an electric axle drive device of a motor vehicle having such a dual-clutch device.

[0002] DE 10 2013 219 390 A1 discloses a double clutch in which the activation units of the clutches each have a piston and a central part common to both activation units.

[0003] DE10 2004 0480 68 A1 discloses a wet multi-plate clutch designed as a double clutch, each with an actuating piston, on the side of which a fluid-tight compensation chamber is formed.

[0004] From DE 198 30 951 A1 a multi-plate clutch is known which is arranged in a power-split transmission.

[0005] DE 10 2021 006 124 B3 discloses an electric axle drive with two electric machines, which has a differential gear, wherein the differential gear has exactly three shafts, namely the input shaft, the first output shaft and the second output shaft.

[0006] From DE 10 2013 204 974 A1 a dual clutch device with two hydraulically actuated multi-plate clutches arranged axially next to one another according to the preamble of claim 1 is known.

[0007] DE 10 2008 060 580 B4 discloses the design of centrifugal oil shroud overflow channels in a dual clutch. In such clutches with centrifugal force compensation, the fluid required for compensation is often thrown off through open holes in a rotating shaft. This fluid must then be trapped by the centrifugal oil shroud until it is completely filled. The disadvantage of such arrangements is that the fluid supply is not loss-free, which delays the filling of the centrifugal oil shroud. Furthermore, with this design, it cannot be guaranteed that the centrifugal oil shrouds in both clutches can be filled synchronously.

[0008] The object of the invention is to ensure faster and synchronous filling of the centrifugal oil covers in a hydraulic dual clutch device.

[0009] The invention is based on the features of the independent claims. Advantageous developments and refinements are the subject of the dependent claims.

[0010] The object is achieved according to claim 1 in that the first actuating piston with the first pressure chamber and at least one first pressure oil supply channel and the first centrifugal oil chamber and at least one first centrifugal oil supply channel of the first centrifugal oil chamber on the one hand, and the second actuating piston with the second pressure chamber and at least one second pressure oil supply channel and the second centrifugal oil chamber and at least one second centrifugal oil supply channel for the second centrifugal oil chamber on the other hand each have the same dimensions.

[0011] In the embodiment according to the invention, “same dimensions” is to be understood as meaning that the channels, in particular in a design drawing of the dual clutch device, each have the same lengths and flow cross-sections and the pressure chambers and centrifugal oil chambers each have the same oil volumes and the same inner and outer diameters of the sealing rings, taking into account usual manufacturing tolerances.

[0012] Identically designed supply channels result in an exactly 50 / 50 split of the fluid mass flow, resulting in synchronous response of the two clutches. Short lines due to the inventive design with the actuating devices located centrally between the plate packs improve spontaneity, which is particularly advantageous when installing the dual clutch device in a motor vehicle with two electric drive motors in so-called boost mode, in which both drive motors are operated. A highly reliable, synchronous response and thus synchronous engagement of the two clutches is important. Furthermore, the invention prevents repercussions on the centrifugal oil pressure level caused by a change in the inlet mass flow.

[0013] According to an advantageous embodiment of the invention, the centrifugal oil chambers, the actuating pistons with the pressure chambers, and the supply channels are designed to be mirror-symmetrical to one another. This ensures absolutely synchronous response and operating behavior of the two multi-plate clutches.

[0014] According to an advantageous development of the invention, the centrifugal oil supply channels are designed to be closed. This ensures rapid filling of the centrifugal oil hoods.

[0015] According to the invention, the at least one first centrifugal oil channel has a first transverse channel section running parallel to a rotational axis and at least one radially outwardly directed first connecting channel section, the at least one second centrifugal oil supply channel has a second transverse channel section running parallel to the rotational axis and at least one radially outwardly directed second connecting channel section, wherein at least one radially inwardly directed first overflow channel is provided for the first centrifugal oil chamber, which extends from the first transverse channel section to a first overflow edge, and at least one radially inwardly directed second overflow channel is provided for the second centrifugal oil chamber, which extends from the second transverse channel section to a second overflow edge,wherein the overflow channels and overflow edges have the same dimensions, and wherein a respective pressure loss of the respective overflow channel is smaller than a respective pressure loss of the respective at least one connecting channel section. Advantageously, the first and second overflow channels are each designed as circumferential annular channels. This design enables the use of the centrifugal oil for lubrication and cooling of the multi-plate clutches.

[0016] During operation, as soon as a centrifugal oil chamber is filled, the oil level rises radially inward to the respective overflow edge of the respective overflow ring channel. The excess oil then flows from the overflow ring channel into the plate pack, serving to cool the plate pack.

[0017] The dethrottling via the annular channel prevents crosstalk of the delivery pressure to the centrifugal oil chamber, so that a change in the inlet mass flow has no effect on the pressure level in the centrifugal oil hood chamber.

[0018] According to an advantageous development, a radial position of the first and second transverse channel sections is arranged radially closer to an overflow edge than to a lower edge of the actuating pistons. Preferably, the radial position of the first and second transverse channel sections is arranged in a ratio of approximately 7 / 3 relative to a radial distance from a lower edge of the actuating pistons to an overflow edge. By selecting a length of approximately 70%, relative to the above-mentioned distance, a sufficiently large throttling effect is achieved across at least one transverse channel section, so that crosstalk of the delivery pressure to the centrifugal oil chamber is avoided.

[0019] According to an advantageous development of the invention, a fluid connection is provided between a respective centrifugal oil chamber around the respective overflow edge and a respective fin chamber. The oil flowing over the overflow edge enters the fin chamber through this design and can be used to cool the fins.

[0020] The object is further achieved by a drive device with a dual clutch device according to one of the preceding claims and an electric drive machine of a motor vehicle with a first and a second drive wheel, wherein each multi-plate clutch has an inner plate carrier for receiving inner plates and an outer plate carrier for receiving outer plates, wherein the inner plate carriers are connected to the electric drive machine, wherein a first outer plate carrier at least indirectly forms an output to the first drive wheel and a second outer plate carrier at least indirectly forms an output to the second drive wheel, and wherein the first and the second drive wheel are assigned to a common drive axle. In this drive concept, the simultaneous engagement of the clutches is very advantageous for driving comfort and has a wear-reducing effect.

[0021] According to an advantageous development of the invention, the inner plates are each firmly connected to the inner plate carrier, and the inner plate carriers of the two plate packs of the two multi-plate clutches are firmly connected to each other. A firm connection is advantageous because a closed supply channel system with short channels without rotating oil transfer points, thus with minimal leakage, and with reliably consistent (symmetrical) dimensions is technically easy to implement.

[0022] Further advantages, features, and details will become apparent from the following description, in which at least one embodiment is described in detail—possibly with reference to the drawings. Identical, similar, and / or functionally equivalent parts are provided with the same reference numerals.

[0023] They show: Fig. 1 a schematic representation of a dual clutch device; Fig. 2 shows an axial partial section through a dual clutch device; Fig. 3 an enlarged section of Fig. 2.

[0024] The two Fig. 1 and Fig. 2 each show a dual clutch device 10, which consists of two mirror-symmetrically designed and arranged multi-plate clutches 12a, 12b. An input shaft 14 or its two-part hub is firmly connected to two inner disk packs 16a, 16b of the two multi-plate clutches 12a, 12b. As only in Fig. 1, a first outer disk pack 18a of the multi-disk clutch 12a is coupled to a first output shaft 20. A second outer disk pack 18b of the multi-disk clutch 12b is coupled to a second output shaft 22. In Fig. 1 also shows the rotational axis 24 of the dual clutch device 10. A substantially disc-like piston chamber rear wall 26, which forms the plane of symmetry with the two multi-plate clutches 12a, 12b and is rigidly connected to the input shaft 14, and two actuating pistons 28a, 28b form two pressurizable pressure chambers 30a, 30b therebetween, which are individually supplied with pressurized oil via pressurized oil supply channels 33a, 33b when the associated multi-plate clutch 12a, 12b is to be engaged.

[0025] In order to disengage the multi-plate clutches 12a, 12b again when the actuating pistons 28a, 28b are depressurized, two piston springs 32a, 32b are provided, which in this state then move the respective actuating piston 28a, 28b back in the direction of the piston chamber rear wall 26.

[0026] The piston springs 32a, 32b are each arranged in two annular centrifugal oil chambers 34a, 34b, which are formed on the sides of the actuating pistons 28a, 28b opposite the pressure chambers 30a, 30b. The arrangement of centrifugal oil chambers 34a, 34b compensates for the centrifugal force-induced pressure increase caused by the rotation of the input shaft 14 and thus of the pressure chambers 30a, 30b, particularly in electric machines with very high speeds, because the same pressure increase prevails in the centrifugal oil chambers 34a, 34b. This allows the actuating pistons 28a, 28b and thus the multi-plate clutches 12a, 12b to be controlled more precisely than without such centrifugal oil chambers 34a, 34b. The centrifugal oil chambers 34a, 34b are fed via centrifugal oil supply channels 36a, 36b via a common centrifugal oil line 38 from an oil source (not shown).At least two, preferably three, a maximum of six centrifugal oil supply channels 36a, 36b are milled into a hub, evenly distributed over the circumference.

[0027] Now, in particular, Fig. 3. The two centrifugal oil supply channels 36a, 36b branching off from the common centrifugal oil line 38 on both sides each comprise transverse channel sections 40a, 40b, which extend parallel to the rotational axis 24 of the dual clutch device 10 and from which radially outwardly extending connecting channel sections 42a, 42b branch off for connection to the centrifugal oil chambers 34a, 34b. Extending radially inward from the transverse channel sections 40a, 40b are two overflow channels 44a, 44b, preferably designed as annular channels, which extend to annular

[0028] Overflow edges 46a, 46b extend radially inward. Axially behind the overflow edges 46a, 46b are two plate spaces 48a, 48b, in which the inner and outer plate packs 16a, 16b, 18a, 18b are arranged. The oil flowing over the overflow edges 46a, 46b passes through this formation into the associated plate space 48a, 48b and can be used to cool the plate packs 16, 18. Due to the effect of centrifugal force, the oil flows radially outward and, after cooling the plate packs 16, 18, is discharged radially outward through openings (not shown).

[0029] The transverse channel sections 40a, 40b are therefore located radially between the associated radially inner overflow edges 46a, 46b and lower edges 50a, 50b of the respective actuating pistons 28a, 28b, and are located closer to the overflow edges 46a, 46b than to the lower edges 50a, 50b of the actuating pistons 28a, 28b, relative to the center axes of the transverse channel sections 40a, 40b. In particular, the ratio a / b is between 6 / 4 and 8 / 2, preferably 7 / 3, with a = distance of the central axis of a transverse channel section 40a, 40b to the lower edge 50a, 50b of the respective actuating piston 28a, 28b b = distance from the center axis of a transverse channel section 40a, 40b to the overflow edges 46a, 46b. Here, a is preferably at least 10 mm.

[0030] In this way, a sufficiently large throttling effect is achieved via at least one connecting channel section in each case, so that crosstalk of the delivery pressure to the associated centrifugal oil chamber is avoided.

[0031] There are then several (2 - 6) radially directed connecting channel sections 42a, 42b between the transverse channel sections 40a, 40b and each centrifugal oil chamber 34a, 34b for filling the respective centrifugal oil chamber 34a, 34b, but a completely circumferential and thus low-pressure-loss annular overflow channel 44a, 44b between the transverse channel sections 40a, 40b and the plate packs 16, 18. This advantageously has the effect that the sum of the pressure losses of the transverse channel sections 40a, 40b to the respective centrifugal oil chamber 34a, 34b is much greater than the pressure loss of the annular overflow channel 44a, 44b between the transverse channel section 40a, 40b and the plate packs 16, 18 for supplying cooling oil to the respective plate packs 16, 18.

[0032] Although the invention has been illustrated and explained in detail by means of preferred embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that a multitude of possible variations exist. It is also clear that the embodiments mentioned by way of example are truly only examples and should not be construed as limiting the scope, possible applications, or configuration of the invention in any way.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without departing from the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description. List of reference symbols 10 Dual clutch device 12a, b multi-plate clutch 14 Input shaft 16a,b inner disk packs 18a, b outer disc packs 20 first output shaft 22 second output shaft 24 axis of rotation 26 piston chamber rear wall 28a,b actuating piston 30a,b pressure chamber 32a,b piston spring 33a, b Pressure oil supply channel 34a, b Centrifugal oil room 36a,b Centrifugal oil supply channel 38 Centrifugal oil pipeline 40a,b cross-channel section 42a,b connecting channel section 44a,b overflow channel 46a, b overflow edge 48a,b slatted space 50a,b Lower edge of an actuating piston

Claims

[1] Dual clutch device (10) for an electric axle drive device of a motor vehicle with a first hydraulically actuated multi-plate clutch (12a) and a second hydraulically actuated multi-plate clutch (12b) arranged axially next to the first multi-plate clutch (12a), wherein a first actuating piston (28a) with a first pressure chamber (30a) and a second actuating piston (28b) with a second pressure chamber (30b) are arranged axially between the multi-plate clutches (12a, 12b), wherein a first centrifugal oil chamber (34a) is provided for the first pressure chamber (30a) and a second centrifugal oil chamber (34b) is provided for the second pressure chamber (30b), wherein - the first actuating piston (28a) with the first pressure chamber (30a) and at least one first pressure oil supply channel (33a) and the first centrifugal oil chamber (34a) and at least one first centrifugal oil supply channel (36a) of the first centrifugal oil chamber (34a) on the one hand, and - the second actuating piston (28b) with the second pressure chamber (30b) and at least one second pressure oil supply channel (33b) and the second centrifugal oil chamber (34b) and at least one second centrifugal oil supply channel (36b) for the second centrifugal oil chamber (34b) on the other hand each have the same dimensions, and wherein - the at least one first centrifugal oil supply channel (36a) has a first transverse channel section (40a) running parallel to a rotation axis (24) and at least one radially outwardly directed first connecting channel section (42a), - the at least one second centrifugal oil supply channel (36b) has a second transverse channel section (40b) running parallel to the axis of rotation (24) and at least one radially outwardly directed second connecting channel section (42b), - at least one radially inwardly directed first overflow channel (44a) is provided for the first centrifugal oil chamber (34a), which extends from the first transverse channel section (40a) to a first overflow edge (46a), and - at least one radially inwardly directed second overflow channel (44b) is provided for the second centrifugal oil chamber (34b), which extends from the second transverse channel section (40b) to a second overflow edge (46b), wherein - the overflow channels (44a, 44b) and overflow edges (46a, 46b) have the same dimensions and wherein a respective pressure loss caused by the respective overflow channel (44a, 44b) is smaller than a respective pressure loss of the respective at least one connecting channel section (42, 42b). [2] Double clutch device according to claim 1, characterized bythat the centrifugal oil chambers (34a, 34b), the actuating pistons (28a, 28b) with the pressure chambers (30a, 30b) and the supply channels (33a, 33b, 36a, 36b) are mirror-symmetrical to one another. [3] Double clutch device according to claim 1 or 2, characterized by that the centrifugal oil supply channels (36a, 36b) are closed. [4] Double clutch device according to one of the preceding claims, characterized by that the first and second overflow channels (44a, 44b) are each designed as a circumferential annular channel. [5] Double clutch device according to one of the preceding claims, characterized by that a radial position of the first and second transverse channel sections (40a, 40b) is radially closer to the overflow edge (46a, 46b) than a lower edge (50a, 50b) of the actuating pistons (28a, 28b). [6] Double clutch device according to claim 5, characterized bythat the radial position of the first and second transverse channel sections (40a, 40b) is arranged in a ratio of approximately 7 / 3 with respect to a radial distance from the lower edge (50a, 50b) of the actuating pistons (28a, 28b) to an overflow edge (46a, 46b). [7] Double clutch device according to one of claims 5 or 6, characterized by that a fluid connection is provided from a respective centrifugal oil chamber (34a, 34b) around the respective overflow edge (46a, 46b) and a respective lamella chamber (48a, 48b). [8] Drive device with a dual clutch device according to one of the preceding claims and an electric drive machine of a motor vehicle with a first and a second drive wheel, characterized byin that each multi-plate clutch (12a, 12b) has an inner plate carrier for receiving inner plates (16) and an outer plate carrier for receiving outer plates (18), wherein the inner plate carriers are connected to the electric drive machine, wherein a first outer plate carrier at least indirectly forms an output to the first drive wheel and a second outer plate carrier at least indirectly forms an output to the second drive wheel, wherein the first and the second drive wheel are assigned to a common drive axle. [9] Drive device according to claim 8, characterized by that the inner plates (16) are each firmly connected to the inner plate carrier and the inner plate carriers of the two plate packs (16, 18) of the two multi-plate clutches (12a, 12b) are firmly connected to one another.

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