Multi-plate brake or multi-plate clutch with external lubrication

Abstract

Multi-plate brake or multi-plate clutch (20) with external lubrication by means of a nozzle (45), wherein the plates have shark fin-shaped friction segments (42) which are spaced apart from one another by means of segmentation grooves (15). Drag grooves (17) in the form of recesses are formed on the outer edge of the carrier disk of the plate.

Description

[0001] Multi-plate brake or multi-plate clutch with external lubrication

[0002] The invention relates to a wet-running multi-disc brake with external lubrication having the features according to the preamble of claim 1.

[0003] The application area of ​​the invention: Wet multi-disc brakes in hybrid modules, DHT and switchable e-axles, low-loss multi-disc brakes as switching and separating elements for hybrid modules and e-axles, locking differentials (Limited Slip Differential LSD, eLSD, Locking Differential), disconnect clutches, dual clutches, brakes, torque limiters, torque vectoring modules, etc.

[0004] Wet multi-plate clutches and brakes are widely used in conventional powershift transmissions, in novel hybrid modules in highly stressed drive trains or in switchable e-axles, and represent high-performance, highly stressed components.

[0005] The demands for lower CO2 emissions and improved efficiency of powertrains in automotive applications are of great importance. In addition to reducing load-independent losses in switching elements, thermal stress and adequate cooling must be considered. The groove pattern of the friction plate plays a central role in the interplay between friction characteristics, heat management, and efficiency.

[0006] In a limited-slip differential (LSD, eLSD), unlike other products such as a wet clutch, the lubrication and cooling of the clutch pack is often achieved via an external nozzle, as illustrated in DE 10 2019 105 053 A1, instead of internally as is typical for wet clutches. The available flow rates are also significantly lower. WO 2019 / 120 370 A1, US 8 474 590 B2, and EP 3 374 652 B1 each depict ring-shaped, wet-running friction elements with grooves in the friction surface.

[0007] DE 697 08 447 T2 discloses grooved friction plates for the drainage of oil through different groove shapes in a wet clutch.

[0008] DE 10 2021 120 275 A1 discloses a lamellar brake with external lubrication and friction plates with pentagonal friction lining pads and additional embossed grooves.

[0009] DE 10 2020 127 423 A1 discloses a lamellar brake with external lubrication and friction lamellae with friction surfaces, each having a zigzag or wave-shaped or tangential groove running around the circumference.

[0010] DE 10 2019 105 053 A1 reveals an oil-lubricated limited-slip differential.

[0011] Disadvantage: In the case of ring-shaped, wet-running friction systems with external lubrication - also referred to as external oiling in this document - especially in the case of multi-disc brakes with external oiling (see Fig. 2), it is not possible to use proven groove patterns such as those already available for internal oiling.

[0012] Within the context of this document, the terms groove pattern, groove geometry, and groove design are used synonymously.

[0013] Within this document, the terms pad geometry, pad pattern, and pad design are used synonymously.

[0014] The terms pad, lining pad, friction lining pad, and friction segment are used synonymously in this document. The terms steel lamellae and counter lamella are also used synonymously in this document.

[0015] The terms friction lamella and carrier lamella are also used synonymously in this document.

[0016] The terms carrier plate of the friction lamella and carrier disc of the friction lamella are also used synonymously in this document.

[0017] In many applications, the clutch pack is lubricated from the inside. The oil is forced outwards through the grooves of the friction plates – also referred to as friction plates or carrier plates in this document – ​​by centrifugal force, thus providing both lubrication and cooling. However, in some applications, such as limited-slip differentials, lubrication is often applied to the clutch pack from the outside via a nozzle.

[0018] The invention is therefore based on the objective of improving convective cooling or the cooling effect in the friction zone and minimizing drag losses in wet-running friction systems with external lubrication, for example in multi-disc brakes with external lubrication, by means of a suitable groove pattern. A friction disc design optimized for external lubrication is to be proposed. Lubrication and cooling should also be ensured at low speeds.

[0019] The problem is solved by a multi-disc brake or a multi-disc clutch with the features according to claim 1. In particular, this is a wet-running multi-disc brake with external lubrication or a multi-disc clutch with external lubrication.

[0020] In wet-running multi-plate brakes or clutches, such a groove pattern improves the cooling effect and reduces drag losses. The problem is thus solved by a multi-plate brake or clutch for wet operation using a fluid, with a plate pack arranged around a rotational axis of the brake or clutch and axially loadable to form a frictional connection. This pack consists of alternating axially layered friction plates and counter plates, wherein the friction plates are rotationally connected to a first plate carrier and the counter plates to a second plate carrier. Each plate carrier is assigned to an input section and the other to an output section of the brake or clutch. Each friction plate has an annular carrier disc with an outer and an inner edge and friction segments fixed to both sides of the carrier disc.It is provided that 12 to 36, preferably 24, friction segments are distributed around the circumference on each of the two sides, and that the friction segments on each of the two sides are spaced apart from each other in the circumferential direction by means of segmentation grooves, and that the segmentation grooves form a passage space for the fluid, and that drag grooves in the form of recesses are arranged on the outer edge of each carrier disc, wherein the fluid is injected radially outwards onto the outer edge of the carrier disc by means of a nozzle which is rotatably arranged relative to the friction lamella together with the carrier disc, so that the fluid penetrates into the drag grooves and the segmentation grooves, wherein each friction segment has a shark fin-shaped form with an additional collecting groove in the form of a recess from a rear edge of the shark fin-shaped form of the friction segment.

[0021] In a preferred embodiment of the multi-plate brake or the multi-plate clutch, the nozzle is arranged to be fixed to the housing.

[0022] In particular, the friction lamella and carrier disc are rotatable relative to the housing and the nozzle attached to it.

[0023] In a preferred embodiment of the multi-plate brake or the multi-plate clutch, the predetermined angle of the nozzle, i.e., the direction of the oil jet, is designed to coincide with the opening direction of the segmenting groove or to be optimized in a way that is suitable for each other. In a preferred embodiment of the multi-plate brake or the multi-plate clutch, the drag grooves are designed in the form of circular segment-shaped recesses.

[0024] In a preferred embodiment of the multi-plate brake or the multi-plate clutch, the collecting groove is designed in the form of a circular segment-shaped recess.

[0025] In a preferred embodiment of the multi-plate brake or the multi-plate clutch, it is provided that each drag groove is arranged relative to each segmentation groove by offsetting the drag groove by an angle specified in the circumferential direction relative to the segmentation groove.

[0026] In a preferred embodiment of the multi-plate brake or the multi-plate clutch, it is provided that each drag groove is arranged relative to each segmentation groove by offsetting the drag groove by an angle specified in the circumferential direction relative to the segmentation groove.

[0027] In a preferred embodiment of the multi-plate brake or the multi-plate clutch, it is provided that the centers of the circular segments of the recesses of the collecting grooves lie on a predetermined pitch circle diameter.

[0028] In a preferred embodiment of the multi-plate brake or the multi-plate clutch, friction segments, segmentation grooves and drag grooves are arranged evenly distributed around the circumference.

[0029] In a preferred embodiment of the multi-plate brake or the multi-plate clutch, it is provided that the shark-fin-shaped friction segments distributed around the circumference form an annular friction surface which has an inner edge radially inside and an outer edge radially outside, wherein a friction segment has a concave lower edge which runs on the inner edge, a convex front edge which extends in its radially outer course to the outer edge and the concave rear edge with the circular segment-shaped recess of the collecting groove.

[0030] A preferred embodiment of the multi-plate brake or multi-plate clutch is characterized in that all edges of the friction segment are arcuate, i.e., not straight, but curved: The front edge is convex. The lower edge, rear edge, and the circular segment-shaped recess are concave. All edges and the circular segment-shaped recess are connected to the complete outer circumference of the friction segment by rounded corners. The friction segment has five such corners.

[0031] A preferred embodiment of the multi-plate brake or multi-plate clutch is characterized in that the tip of the shark fin-shaped element is arranged radially outward. The tip of the shark fin is thus located on, or almost on, the outer edge of the annular friction surface. The base of the shark fin-shaped element is arranged radially inward. The base of the shark fin is thus located on the inner edge of the annular friction surface.

[0032] A preferred embodiment of the multi-plate brake or the multi-plate clutch is characterized in that the outer and inner edges of the annular friction surface and the outer and inner edges of the carrier disc run coaxially.

[0033] Depending on the intended rotational speeds of the fins in the application, the position and angle of the nozzle, as well as the groove design, can be adjusted accordingly to ensure optimal lubrication and cooling.

[0034] In a preferred embodiment of the multi-plate brake or the multi-plate clutch, it is provided that the oil jet from the nozzle is inclined at a predetermined angle to a tangent of the outer edge of the annular friction surface or the outer edge of the carrier disc, or alternatively, that the oil jet from the nozzle is inclined at another predetermined angle to an opening direction of the segmentation grooves at their radially outer end.

[0035] In this way, the oil jet influences the rotational speed of the friction plate which is arranged axially between two counter plates, in particular by the rear edge with the circular segment-shaped recess of the collecting groove of the friction segment, according to the principle of a paddle wheel bombarded with an oil jet, influencing the rotational speed of the friction plate.

[0036] Another preferred embodiment of the multi-plate brake or the multi-plate clutch is characterized in that the oil jet from the nozzle also influences the rotational speed of the friction plate when irradiating the leading edge of the friction segment, according to the principle of an inverted paddle wheel being bombarded with an oil jet.

[0037] Another preferred embodiment of the multi-plate brake or the multi-plate clutch is characterized in that the orientation of the friction segments on both sides of the carrier disc is the same.

[0038] Another preferred embodiment of the multi-plate brake or the multi-plate clutch is characterized in that the orientation of the friction segments on both sides of the carrier disc is opposite.

[0039] Another preferred embodiment of the multi-plate brake or the multi-plate clutch is characterized in that the friction segments are arranged identically on both sides of the carrier disc.

[0040] The task is also solved by the friction segment for a groove pattern described above. The task is also solved by the friction plate for a multi-plate brake or multi-plate clutch described above.

[0041] The invention further relates to a friction pad for a previously described groove pattern. The friction pads are available separately.

[0042] Further advantages and advantageous embodiments of the invention are the subject of the following figures and their description.

[0043] They show in detail:

[0044] Figure 1 State of the art: Common groove design of friction linings (Source: ZF).

[0045] Figure 2 Wet multi-disc brake with external lubrication.

[0046] • General: Lubrication concepts for wet multi-plate clutches and multi-plate brakes

[0047] • Schematic diagram of a wet multi-disc brake with external lubrication

[0048] Figure 3 Pad geometry “shark fin” for friction plate with external lubrication | Design features

[0049] Figure 4 Pad geometry “shark fin” for friction plate with external lubrication | Design features

[0050] Figure 5 Pad geometry “shark fin” for friction plate with external lubrication | Design features

[0051] Figure 6 Pad geometry “shark fin” for friction plate with external lubrication | Operating principle

[0052] Figure 7 Friction plate with external lubrication | Operating principle | Drag groove in outer friction plate

[0053] Figure 8 Friction plate with external lubrication | Operating principle | Drag groove in outer friction plate

[0054] Figure 9 Friction plate with external lubrication | Operating principle | Drag groove in outer friction plate

[0055] Figure 10 Groove pattern for externally lubricated friction systems | preferred groove design Figure 11 Groove pattern for externally lubricated friction systems | variations of the preferred groove design

[0056] Figure 1 shows various known groove patterns 62 to 69 in top view. Reference numeral 61 denotes a friction lamella with a friction surface that is not provided with grooves. Radially on the inside, the friction lamella has internal teeth for engaging the friction lamella in a (not shown) lamella carrier.

[0057] Groove pattern 62 comprises radial grooves. Groove pattern 63 comprises cross grooves. Groove pattern 64 comprises parallel grooves arranged in groups. Groove pattern 65 comprises crosswise arranged blind grooves. Groove pattern 66 comprises spiral grooves. Groove pattern 67 comprises waffle grooves. Groove pattern 68 comprises sunburst grooves. Groove pattern 69 comprises an annular groove with pressure relief holes.

[0058] Even when the switching element is closed, the groove pattern serves to cool the friction plates through an oil flow. Furthermore, the grooves serve to cut the oil film, thereby stabilizing the coefficient of friction. This creates the desired friction behavior during shifting. When the switching element is open, the grooves also allow the drag torque to be influenced and reduced.

[0059] Figures 2a and 2b schematically depict a wet multi-plate brake 20 in different views. Figure 2a illustrates various lubrication concepts 21, 22, 23 for wet multi-plate clutches and multi-plate brakes, respectively. The lubrication concepts 21 to 23 can be implemented differently for wet multi-plate clutches and multi-plate brakes, depending on the application.

[0060] Generally, the cooling oil for friction systems is supplied from the inside either actively, for example in dual-clutch transmissions with pressure lubrication, or passively, for example in shift elements of automatic transmissions with passive oil distribution within the gearbox, as illustrated by arrow 24 and double arrow 25. Depending on the gearbox design, the friction system can also operate in an oil bath, as indicated by figure 23. In the special case of multi-plate brakes, such as those used in automatic transmissions, hybrid gearboxes, or e-axles, active external lubrication can be advantageous, as indicated by arrow 26 in figure 22.

[0061] In Figure 2b, an arrow indicates that an inner plate carrier 27 of the wet multi-plate brake 20 rotates at a speed w. One of a total of four friction plates 28 is engaged in the inner plate carrier 27. The friction plates 28 are connected to the inner plate carrier 27 in a rotationally fixed manner by means of corresponding internal teeth.

[0062] The friction plates 28 are arranged axially between two steel plates 29, which are rotationally fixed to an outer plate carrier 30 of the wet-running multi-plate brake 20. Arrows n and r indicate aThe inner and outer radii of annular friction surfaces between the steel plates 29 and the friction plates 28 are indicated when the wet-running multi-plate brake 20 is closed. An arrow h in Figure 2b illustrates that the steel plates 29 are axially spaced from the friction plates 28 when the multi-plate brake 20 is open. The term "axial" refers to a rotation axis 33 of the wet-running multi-plate brake 20.

[0063] Multi-disc brakes are generally used as internal switching elements for shifting under load in rotary transmissions. Wet multi-disc brakes 20, as shown in Figures 2a and 2b, are used in automatic transmissions, DHT transmissions and / or in multi-stage e-axles.

[0064] When the brake is closed, the friction plates and the steel plates in the disc pack of the multi-plate brake are pressed together.

[0065] Figures 3 to 5: Groove patterns for externally lubricated friction systems | Design features

[0066] The number of segmentation grooves 15 corresponds to a multiple or a divisor of the number of teeth of the gear. The segmentation grooves 15 increase in size radially from the inside out (funnel shape), i.e., the cross-sectional area increases, thus advantageously achieving a diffuser effect.

[0067] The collecting groove 16 for the oil is located on the mean friction diameter 8, which is calculated as follows: mean friction diameter = ( Da + Di ) / 2 , with Da: friction diameter of the friction surface radially outside, Di: friction diameter of the friction surface radially inside.

[0068] The opening direction of the segmentation groove 15 for the oil jet 44 is oriented towards the nozzle 45, so that if the friction lamella 28 rotates in the opposite direction to the oil jet 44, the rotation of the friction lamella is slowed down (principle of a paddle wheel, see Fig. 6): The oil jet 44 reaches the drag groove 17, 40 in the direction of the jet 44, which is arranged on the outer edge of the support lamella in the opening direction of the segmentation groove 15, and enters the segmentation groove 15 there – more so than in the other areas of the outer edge of the support lamella – and the oil is forced radially inwards along the segmentation groove 15 and collects in the concave areas of the shark fin-shaped friction segment 42, i.e., on the rear edge 57 with the circular segment-shaped collecting groove 16.

[0069] The position and orientation (angle) of the nozzle 45, the opening direction of the segmentation groove 15 in its radially outer region, the position of the drag groove 17, 40 relative to the segmentation groove 15, the radius of the circular arc-shaped, concave rear edge 57 of the shark fin-shaped friction segment 42, and the arrangement of the concave, circular segment-shaped collecting groove 16, as well as the radius of the circular arc-shaped, convex front edge 56 of the shark fin-shaped friction segment 42, which forms the segmentation groove 15, are coordinated with regard to the course of the oil jet and the further oil flow in the segmentation groove 15 in order to ensure optimal lubrication and cooling.

[0070] The predetermined angle of the nozzle 45, i.e., the direction of the oil jet, can coincide with the opening direction of the segmentation groove 15 or, after optimization, deviate slightly from it. The oil jet from the nozzle is then inclined at a different predetermined angle relative to the opening direction of the segmentation groove 15 at its radially outer end.

[0071] The drag grooves 17, 40 are circular segment-shaped and are located on the outer edge of the support lamella, in the middle of the intersection area of ​​an imaginary extension of each segmentation groove 15 with the outer edge of the support lamella and wherein the diameter 4 of the drag grooves 17, 40 is always chosen to be smaller than the width of the segmentation grooves 15 radially outwards.

[0072] The 5 corners (9, 18) - also referred to as pad outer radii 18 - of each friction segment 42 are always rounded.

[0073] The pad edges of each friction segment 42, which form the segmentation grooves 15, i.e. front edge 56, back edge 57 and circular segment collecting groove 16, are always curved and not straight.

[0074] Figures 6 to 9: Groove pattern for friction systems with external lubrication | Functional principle | Pad geometry “shark fin” and drag groove in the outer support lamella.

[0075] The above task is solved by two design elements of the friction lamella 28, 52:

[0076] 1. Optimized pad and groove design of the friction plate 28, 52, specially optimized for external oiling:

[0077] When oiling with an oil jet 44 from the radial outside onto the outer edge of the support lamella 28, 43 by means of a nozzle 45, the oil of the oil jet 44, according to the principle of a funnel, passes through the large drag groove 17, 40 on the outer edge of the support lamella 28, 43, between the lining pads 42 into the segmenting groove 15, which narrows further from radial outside to inside. For this purpose, the oil jet 44 runs in the plane of the friction lamella 28, 52 and can run strictly radially, i.e., perpendicular to the tangent to the friction lamella 28, 52, or preferably not perpendicular to the tangent, but inclined to the perpendicular to the tangent, yet still in the plane of the friction lamella 28, 52 as shown in Figs. 6 and 8. Since the oil, due to thisDue to the funnel effect, less oil enters the segmenting groove 15 than the other areas of the outer edge of the support lamella, and more oil hits the convexly shaped front edge 56 of the shark fin-shaped friction segment 42 and the concavely shaped rear edge 57 with the circular segment-shaped collecting groove 16 as an additional - also concave - recess, so that in this way the principle of a paddle wheel is realized (see Fig. 6).

[0078] The oil collects in the collecting groove 16, which is radially centered between the inner edge 2 and outer edge 1 of the annular friction surface or the lining pads 42, both when the machine is stationary and when rotating. Depending on the oil viscosity, temperature, rotational speed, and flow rate from the nozzle 45, the ideal design for lubrication and cooling can be constructed.

[0079] Depending on the intended rotational speeds of the fins in the application, the position and angle of the nozzle, as well as the groove design, can be adjusted accordingly to ensure optimal lubrication and cooling.

[0080] 2. Drag groove 17, 40, 4, 5 in the outer edge of the support lamella:

[0081] The oil from the oil jet 44 flows between each pair of adjacent steel plates (counter plates) 29, primarily through the drag grooves 17, 40 in the carrier plate, i.e., in the carrier disc of the carrier plate 28, 52, further radially inwards towards the lining pads 42 (see Fig. 8, BZ 49). The oil is guided through the grooves 49 into the drag grooves 17, 40 where it penetrates the segmentation grooves 15 and wets the friction surfaces between friction plates 28, 52 and steel plates 29, 53 with oil.

[0082] At a differential speed between friction plate 28, 52 and steel plate 29, 53 or housing 46, adhering / collected oil is carried along, the segmentation groove 15 transports or distributes the oil in the direction of rotation not only on the friction surfaces but also in the housing (depending, among other things, on temperature and viscosity of the oil), which also provides cooling and lubrication.

[0083] Due to the direction of rotation and the corresponding paddle wheel arrangement of the friction lining pads of the "shark fin" pad design relative to the oil jet 44 from the nozzle 45, which is fixed opposite the housing, oil is forced radially inwards both in the stationary, non-rotating state of the friction lamella (carrier lamella) and under rotation.

[0084] The oil jet 44 enters the segmentation groove 15 and the oil collects in the collecting groove 16 radially in the center of the lining pads 42 and is held there, thus promoting cooling and lubrication.

[0085] Figure 9: Groove pattern for friction systems with external lubrication | Operating principle |

[0086] Groove in the outer support lamella (drag groove)

[0087] The oil from the oil jet 44 passes through the notch 40 in the carrier plate (drag groove 40) further inwards towards the lining pads 42.

[0088] The oil is collected in the drag groove 17, 40 and the channel 49 between the two immediately adjacent steel lamellae 29 and wets the friction surfaces.

[0089] Under differential speed between friction plates 28, 52 and steel plates 29, 53 or housing, adhering / collected oil is carried along.

[0090] The segmentation groove 15 also transports and distributes the oil within the housing (depending, among other things, on the temperature and viscosity of the oil). This results in lubrication and cooling.

[0091] Lubrication or cooling:

[0092] In the open state, a shear flow of oil exists between a friction plate 28 and a steel plate 29. The groove design shifts the air intake to lower rotational speeds. This groove design improves the oil removal from the brake 20 and thus reduces drag losses. The groove design also minimizes oil contamination from the gearbox interior when the multi-plate brake 20 is open. Rapid oil removal and spin-off are achieved when the multi-plate brake 20 is open. Both the separation of the plates and the oil removal are facilitated by the groove design. Cooling occurs in the closed state (no rotation of the plates relative to each other).

[0093] The shark-fin-shaped groove design minimizes flow resistance, facilitating the supply of cooling oil from the outside. Targeted oil flow minimizes premature oil runoff from the friction system and ensures uniform cooling across the entire circumference of the system (improving convective cooling). This can improve the thermal management of the switching element and reduce cooling times.

[0094] Drag losses in the open state:

[0095] By considering the interrelationships of air intake, separation behavior, and their impact on drag losses, the groove pattern, in its design (influencing the pressure level Z-distribution in the lubrication gap), can minimize drag losses. Simultaneously, additional passive lubrication of the friction system from within the transmission is reduced. Thus, the goal of a low-loss multi-plate brake as a switching and disengaging element for hybrid modules and e-axles can be supported.

[0096] Functional description of the "shark fin" pad design for friction systems with external lubrication:

[0097] Drag losses - open state:

[0098] The cross-sectional area or width of the segmentation grooves 15 increases from the inside to the outside, thus creating a diffuser effect. This improves oil removal when the brake is open and the friction plates are rotating. This results in an additional pressure reduction in the grooves and in the lubrication gap between the plates, shifting the air intake to lower rotational speeds. The drag torque can therefore be reduced.

[0099] Indirect lubrication from the interior (radially inside) is reduced by the smaller flow cross-section at the inner diameter. This further supports the degreasing of the friction system in the open state and reduces drag losses. Friction coefficient build-up - closing state:

[0100] Improvement of friction coefficient build-up through effective oil removal in the lubrication gap.

[0101] Cooling - closed state:

[0102] Wide groove channels of the segmentation grooves 15, located radially outward, facilitate the supply of oil from the radial outside when the multi-disc brake is closed. A centrally located collecting groove 16 distributes the cooling oil around the circumference of the friction system. The reduced flow cross-section of the radially inner segmentation grooves 15 minimizes the outflow of cooling oil from the friction contact. The opening direction of the segmentation grooves 15 and the collecting grooves 16 allows the externally supplied cooling oil to be optimally directed to the surface of the counter-friction disc (steel disc) 29. This results in improved distribution of the cooling oil and increases the contact area for convective heat transfer between the cooling oil and the steel disc.

[0103] Figure 10 Groove pattern for friction systems with external lubrication | preferred groove design

[0104] Figure 10 shows a preferred groove design formed by 24 friction segments (friction lining pads) 42 on the carrier plate of the friction lamella 43. Immediately adjacent friction segments 42 have a circumferential, radially inward spacing 6 of 1.5 mm. This spacing 6 widens radially outward and forms the segmentation groove 15. The segmentation 3 has a circumferential dimension of 24 * 15°, with each friction segment 42 and an adjacent segmentation groove 15 each forming a segment 3 of 15° of the segmentation.

[0105] When the friction lamella (28, 43, 52) rotates relative to the counter lamella (29, 51), the friction segments 42 sweep over an annular friction surface on the counter lamella (29, 51) (the ring's center is also the axis of rotation 33). This friction surface has an inner edge, designated as friction diameter inner 2 (Di), of 100 mm and an outer edge, designated as friction diameter outer 1 (Da), of 123 mm.

[0106] On the outer edge of each carrier disc (carrier plate) of a friction lamella (carrier lamella) 28, 43, 52, drag grooves 17, 40 in the form of circular segment-shaped recesses are arranged, wherein the position of each drag groove 17, 40 relative to the position of one or more segmentation grooves 15 is determined by, for example, the drag groove 17, 40 being offset from the segmentation groove 15 by a circumferentially predetermined angle. Preferably, the drag grooves 17, 40 are located on the outer edge of the carrier lamella, each at the center of the intersection area of ​​an imaginary extension of each segmentation groove 15 with the outer edge of the carrier disc, and wherein the diameter 4 of the drag grooves 17, 40 is always smaller than the radially outer width of the segmentation grooves 15. The diameter of the drag grooves is preferably 5 mm, and the pitch circle diameter 5 of the drag grooves 17, 40 is 124.8 mm.

[0107] The collecting groove 16 is a circular segment-shaped recess from the concave rear edge 57 of the shark fin-shaped friction segment 42.

[0108] The centers of the circular segment-shaped collecting grooves 16 are also located on a circle (the center of the circle is also the axis of rotation 33) with a pitch circle diameter 8, which corresponds to the mean friction diameter and is calculated as follows: mean friction diameter or pitch circle diameter = (Da + Di) / 2, where Da is the friction diameter of the radially outer friction surface and Di is the friction diameter of the radially inner friction surface. The diameter 7 of the circular segment-shaped collecting grooves 16 is preferably 5 mm, and the pitch circle diameter 8 is 111.5 mm. All edges of a friction segment 42 are arcuate, i.e., not straight, but curved.

[0109] The leading edge 56 is designed as a convex circular arc 11 (friction pad arc right 11) and has a radius of 14.8 mm. The respective centers of the circular arcs 11 themselves also lie on a circle (the center of this circle is also the axis of rotation 33), the diameter of which is preferably smaller than the inner friction diameter (Di) 2 and is, for example, 93.5 mm.

[0110] The rear edge 57 is designed as a concave circular arc 10 (friction pad arc left 10) and has a radius of 15 mm. The respective centers of the circular arcs 10 themselves also lie on a circle, preferably on the one on which the lower edges 58 with friction diameter inside (Di) 2 lie.

[0111] The lower edge 58 and the circular segment-shaped recess of the collecting groove 16 are also designed as concave circular arcs. The lower edge 58 has an inner friction diameter (Di) of 2, and thus a radius of 50 mm. The circular segment-shaped recess of the collecting groove 16 has a diameter 7 of 5 mm, and thus a radius of 2.5 mm.

[0112] All three edges 56, 57, 58 and the circular segment-shaped recess 16 are connected by rounded corners 9 to form the complete outer circumference of the friction segment. The friction segment has 5 such corners, each with an outer radius 9 of 1 mm.

[0113] A preferred embodiment of the multi-plate brake or multi-plate clutch is characterized in that the tip of the shark fin-shaped element is arranged radially outward. The tip of the shark fin is thus located on—or almost on—the outer edge 1 of the annular friction surface. The base of the shark fin-shaped element, corresponding to the lower edge 58, is located radially inward. The base of the shark fin is thus located on the inner edge 2 of the annular friction surface. Depending on the intended rotational speeds of the plates in the application, the position and angle of the nozzle, as well as the groove design, can be adjusted accordingly to ensure optimal lubrication and cooling.

[0114] Figure 11 Groove pattern for friction systems with external lubrication | Variations of the preferred groove design

[0115] Figure 11 and the following table show variations in the dimensioning of also preferred groove designs or friction lining pad designs.

[0116] Of course, a mirrored design is also possible.

[0117] On the front and back of the carrier plate of the carrier lamella 28, friction lining pads 42 are arranged identically on the front and back sides and collect oil in the collecting groove 16 in only one direction of rotation, which is the normal case, e.g., during forward travel. Alternatively, the friction lining pads 42 on the front and back sides can be aligned identically but, unlike in an identical arrangement, can also be offset from each other.

[0118] When driving in reverse and in the opposite direction of rotation, no oil is collected in the collecting groove 16, but this is less relevant due to the lower frequency and lower requirements. In this case, the friction plate (carrier plate) 28, 43, 52 rotates so that the friction lining pads are all moved through the oil with their leading edge 56 facing forward.

[0119] With opposite orientations of the pads 14 on the front and back, oil can be collected in the collecting groove 16 in both directions of rotation, but only on one friction side at a time.

[0120] The direction of rotation is not relevant for the drag groove 17, 40.

[0121] The drag groove 17, 40 can alternatively be designed in a semicircular, U-shaped, rectangular or triangular shape (reference numeral 55).

[0122] Advantageously, the pad or groove design of the segmentation improves friction coefficient build-up through effective oil drainage in the lubrication gap. This allows for smooth closing of the friction system during actuation.

[0123] The increasing cross-sectional area of ​​the segmented grooves 15, from the inside out, creates a diffuser effect. This improves air intake and reduces drag losses.

[0124] Through optimized segmentation, indirect lubrication from the interior can be reduced. This allows additional air to enter the lubrication gap. [Reference symbol]

[0125] Outer edge of the annular friction surface, outer friction diameter (Da)

[0126] Inner edge of the annular friction surface, inner friction diameter (Di)

[0127] segmentation

[0128] Drag groove: Diameter

[0129] Drag groove: Pitch circle diameter

[0130] Segmentation groove between the friction lining pads 42

[0131] Collecting groove: Diameter

[0132] Collecting groove: Pitch circle diameter

[0133] Friction pad: Outer radii

[0134] Friction pad: Radius arc left (back edge 57)

[0135] Friction pad: Radius arc right (front edge 56)

[0136] Friction pad: Radius arc left / right, mirrored design possible

[0137] The friction lining pads on the front and back of the carrier disc of the friction plate are not aligned or are oriented in opposite directions.

[0138] Segmentation groove between the friction lining pads 42

[0139] Collecting groove (paddle wheel principle)

[0140] Drag groove, rounded pad outer radii 9 (friction pad corners)

[0141] Friction pad edges are curved

[0142] multi-disc brake

[0143] Lubrication concept

[0144] Lubrication concept

[0145] Lubrication concept

[0146] Arrow

[0147] Double arrow

[0148] Arrow (external lubrication)

[0149] Inner slat carrier

[0150] Friction plate (carrier plate) with friction lining on carrier plate (carrier disc) of the friction plate

[0151] Counter lamella (steel lamella) Outer lamella support

[0152] axis of rotation

[0153] Drag groove

[0154] Direction of rotation

[0155] Friction segment (friction lining pad)

[0156] Friction plate (carrier plate) with friction lining pad 42 on carrier plate (carrier disc) of the friction plate

[0157] Oil jet

[0158] Nozzle (fixed relative to housing 46)

[0159] Housing

[0160] Rotation direction of housing

[0161] Direction of rotation of friction plate, oil-wetted surfaces or filled drag groove / channel

[0162] Window for oil jet 44 in housing 46

[0163] steel lamella

[0164] Friction plate (carrier plate) with drag groove 40 in the carrier plate of the friction plate; proposed shapes of a drag groove 40 in the carrier plate of the friction plate: semicircular, LI-shape, rectangular, triangular

[0165] Friction segment (friction lining pad arc right 11): Front edge

[0166] Friction segment (friction lining pad arc left 10): back edge

[0167] Friction segment (friction lining pad): lower edge

[0168] friction plate

[0169] Groove pattern

[0170] Groove pattern

[0171] Groove pattern

[0172] Groove pattern

[0173] Groove pattern

[0174] Groove pattern

[0175] Groove pattern

[0176] Groove pattern

Claims

Patent claims 1. Multi-plate brake (20) or multi-plate clutch for wet operation by means of a fluid, comprising a multi-plate assembly arranged about a rotational axis (33) of the multi-plate brake (20) or the multi-plate clutch and axially loadable to form a frictional connection, consisting of alternately axially layered friction plates (28, 43, 52) and counter plates (29, 51), wherein the friction plates (28, 43, 52) are rotationally connected to a first and the counter plates (29) to a second multi-plate carrier (27, 30), and each multi-plate carrier (27, 30) is assigned to an input part and the other multi-plate carrier (27, 30) to an output part of the multi-plate brake (20) or the multi-plate clutch, wherein each friction plate (28, 43, 52) has an annular carrier disk with an outer rim and an inner rim and with friction segments (42) fixedly arranged on both sides of the carrier disk. characterized by the fact that 12 to 36 are distributed around the circumference on each of the two sides,Preferably 24 friction segments (42) are provided and the friction segments (42) are spaced apart from each other circumferentially on each of the two sides by means of segmentation grooves (15) and the segmentation grooves (15) form a passage space for the fluid and wherein drag grooves (17, 40) in the form of recesses are arranged on the outer edge of each carrier disk, wherein the fluid is injected radially outside onto the outer edge of the carrier disk by means of a nozzle (45) which is rotatably arranged relative to the friction lamella (28, 43, 52) together with the carrier disk, so that the fluid penetrates into the drag grooves (17) and the segmentation grooves (15), wherein each friction segment (42) has a shark fin-shaped form (9, 18) with an additional collecting groove (16) in the form of a recess from a rear edge (57, 10) of the shark fin-shaped form (9, 18) of the friction segment (42) shows.

2. Multi-plate brake (20) or multi-plate clutch according to claim 1, characterized in that each drag groove (17, 40) is arranged relative to each segmentation groove (15) by the drag groove (17, 40) being offset by an angle in the circumferential direction relative to the segmentation groove (15).

3. Multi-plate brake (20) or multi-plate clutch according to one of the preceding claims, characterized in that the drag grooves (17, 40) are designed in the form of circular segment-shaped recesses.

4. Multi-plate brake (20) or multi-plate clutch according to one of the preceding claims, characterized in that the collecting groove (16) is designed in the form of a circular segment-shaped recess (7).

5. Multi-plate brake (20) or multi-plate clutch according to one of the preceding claims, characterized in that the centers of the circular segment-shaped recesses (7) of the collecting grooves (16) lie on a predetermined partial circle diameter (8).

6. Multi-plate brake (20) or multi-plate clutch according to one of the preceding claims, characterized in that friction segments (42), segmentation grooves (15) and drag grooves (17, 40) are arranged uniformly distributed over the circumference.

7. Multi-plate brake (20) or multi-plate clutch according to one of the preceding claims, characterized in that the shark fin-shaped friction segments (42) distributed around the circumference form an annular friction surface which has an inner edge (2) radially inside and an outer edge (1) radially outside, wherein a friction segment (42) has a concave lower edge (58) which runs on the inner edge (2), a convex front edge (56) which extends in its radially outer course to the outer edge (1) and a concave rear edge (57) with the circular segment-shaped recess (7) of the collecting groove (16).

8. Multi-plate brake (20) or multi-plate clutch according to one of the preceding claims, characterized in that the oil jet (44) from the nozzle (45) is inclined at a predetermined angle to a tangent of the outer edge (1) of the annular friction surface or the outer edge of the carrier disc, or that the oil jet (44) from the nozzle (45) is inclined at another predetermined angle to an opening direction of the segmentation grooves (15) radially outwards.

9. Multi-plate brake (20) or multi-plate clutch according to one of the preceding claims, characterized in that the orientation of the friction segments (42) on both sides of the carrier disc is the same or that the orientation of the friction segments (42) on both sides of the carrier disc is opposite (14).

10. Multi-plate brake (20) or multi-plate clutch according to one of the preceding claims, characterized in that the friction segments (42) are arranged congruently on both sides of the carrier disc.

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