Torque limiter for a hybrid drivetrain of a motor vehicle
The torque limiter for hybrid powertrains is optimized by a carrier disc with friction lining elements and a disc spring configuration, addressing oversizing issues and enabling efficient torque management and cost reduction.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SCHAEFFLER TECHNOLOGIES AG & CO KG
- Filing Date
- 2025-10-28
- Publication Date
- 2026-05-15
AI Technical Summary
Current torque limiters for hybrid powertrains are oversized and not cost-optimized due to their derivation from friction clutch technology, leading to inefficiencies.
A torque limiter design featuring an input-side carrier disc with perforations for friction lining elements, side parts, and a disc spring that presses against the lining elements, with a specific thickness ratio and shape configuration to enhance cost-effectiveness.
The design allows for a cost-effective manufacturing of the torque limiter while effectively protecting powertrain components by limiting torque and dissipating excess torque as heat.
Smart Images
Figure DE2025100997_15052026_PF_FP_ABST
Abstract
Description
[0001] Torque limiter for the hybrid drivetrain of a motor vehicle
[0002] The present invention relates to a torque limiter, in particular a dry-running torque limiter, for a hybrid powertrain of a motor vehicle. Such torque limiters are currently rather oversized for their actual function because the technology is largely derived from friction clutch technology, i.e., the technology of starting and gear-shifting clutches.
[0003] The object of the present invention is to provide a cost-optimized torque limiter.
[0004] According to the invention, this problem is solved by a torque limiter for a hybrid powertrain of a motor vehicle according to claim 1, comprising an input-side carrier disc which has perforations arranged in the circumferential direction of the torque limiter in which friction lining elements are positively inserted, with two side parts arranged opposite each other on opposite sides of the carrier disc, and with a disc spring which presses a first of these side parts frictionally against first end faces of the friction lining elements, wherein the disc spring bears directly against second end faces of the friction lining elements opposite the first end faces in the axial direction of the torque limiter or acts on them indirectly via a pressure disc.
[0005] Since the ratio of the thickness of the friction lining element measured in the axial direction between the two end faces of a respective friction lining element to the thickness of the carrier disc measured in the axial direction is greater than 1.05, the torque limiter can be manufactured cost-effectively.
[0006] Preferably the ratio is less than 2, so that the torque limiter can be manufactured cost-effectively.
[0007] Preferably, the ratio is in the range of 1.5, so that the torque limiter can be manufactured cost-effectively. It is advantageous if the radial extent of each friction lining element of the torque limiter is greater than the tangential extent of each friction lining element of the torque limiter, thus enabling cost-effective manufacturing of the torque limiter.
[0008] Preferably, each of the friction lining elements has a rectangular base area when viewed in the axial direction, so that the torque limiter can be manufactured cost-effectively.
[0009] Furthermore, preferably each of the friction lining elements has a square base area when viewed in the axial direction, so that the torque limiter can be manufactured cost-effectively.
[0010] It is advantageous if each of the friction lining elements is convex when viewed in the axial direction, which makes it possible to manufacture the torque limiter cost-effectively.
[0011] It is also advantageous if each of the friction lining elements has an oval base surface when viewed in the axial direction, which makes it possible to manufacture the torque limiter cost-effectively.
[0012] Alternatively, it is advantageous if each of the friction lining elements is circular when viewed in the axial direction, which allows the torque limiter to be manufactured cost-effectively.
[0013] Alternatively, it is advantageous if each of the friction lining elements is elliptically shaped when viewed in the axial direction, which makes it possible to manufacture the torque limiter cost-effectively.
[0014] The present invention is explained in more detail below with reference to preferred embodiments in conjunction with the accompanying figures. These show: Figure 1: a first embodiment of a torque limiter, in whose input-side carrier disc round friction lining elements are positively embedded, in a half perspective sectional view.
[0015] Figure 2: the torque limiter from Figure 1 in a top view, with the disc spring and second side part removed to allow a view of the carrier disc with its friction lining elements,
[0016] Figure 3: the carrier disc of the torque limiter from Figures 1 and
[0017] 2 with friction lining element in a sectional view,
[0018] Figure 4: the carrier disc of a second embodiment of a torque limiter, into which square friction lining elements are positively inserted, in a top view,
[0019] Figure 5: the support disc from Figure 4 in a perspective view,
[0020] Figure 6: the carrier disc of a third embodiment of a torque limiter, into which rectangular friction lining elements are positively inserted, in a top view, and
[0021] Figure 7: the support disc from Figure 6 in a perspective view.
[0022] Figures 1 to 7 depict preferred embodiments of a torque limiter 1 for a hybrid powertrain of a motor vehicle, comprising an input-side carrier disc 7 with openings 8 distributed in the circumferential direction U of the torque limiter 1, into which friction lining elements 6 are positively engaged, as well as embodiments of such input-side carrier discs 7 that can be used in such a torque limiter 1. The friction lining elements 6 positively engaged in the openings 8 of the carrier disc 7 are also referred to as lining inlays.
[0023] In particular, with reference to Figures 4 to 7, only the differences of the carrier discs 7 shown therein are described, whereby it is clear that these carrier discs 7 can and are used in the torque limiter 1 shown in Figures 1 and 2. Identical features in this context have the same reference numerals and are described only once. Features that are not presented as essential to the invention in the following description are to be understood as optional.
[0024] The torque limiter 1 shown in Figures 1 and 2 preferably serves to protect the components of a motor vehicle powertrain located downstream of it along the torque transmission path. The torque limiter 1 serves in particular to limit the transmitted torque / torque impulse and thus forms a protective clutch. The torque limiter 1 is therefore implemented as a friction clutch / slip clutch, which slips briefly when an applied torque impulse is exceeded, thereby selectively converting and dissipating this impulse as heat energy so that it is not transmitted further in the powertrain.
[0025] The torque limiter 1 is preferably used in a hybridized powertrain of a motor vehicle, in particular along the torque transmission path between at least one drive machine, such as an internal combustion engine and / or an electric machine, and a transmission.
[0026] As can also be seen in Figures 1 and 2, the torque limiter 1 preferably comprises a torsional vibration damper unit 5 in addition to a slip clutch unit 3. The carrier disk 7 of the torque limiter 1, which is associated with the slip clutch unit 3, forms the input 2 of the torque limiter 1 or the slip clutch unit 3. A hub of the torque limiter 1, which is associated with the torsional vibration damper unit 5, defines an axis of rotation D of the torque limiter 1 and forms the output 4 of the torque limiter 1 or the torsional vibration damper unit 5.
[0027] The torsional vibration damper unit 5 has several spring elements 18, preferably coil springs designed as compression springs, arranged distributed in the circumferential direction U. Preferably, the torsional vibration damper unit 5 has two side parts 11, 12 spaced apart from each other in the axial direction A of the torque limiter 1, into which, more precisely in their windows, the spring elements 18 are inserted.
[0028] The two side parts 11, 12 are arranged axially A on both sides of the carrier disc 7 and overlap with the carrier disc 7 radially R of the torque limiter 1, particularly in the area of the friction lining elements 6 embedded therein. Thus, the two side parts 11, 12 are associated not only with the torsional vibration damper unit 5, but also with the slip clutch unit 3.
[0029] The openings 8 extend axially A through the carrier disc 7 and are spaced apart circumferentially U. A friction lining element 6 is positively engaged in each of these openings 8 within the carrier disc 7, i.e., the inner contour of the opening 8 essentially corresponds to the outer contour of the friction lining element 6, possibly including a necessary or unavoidable clearance.
[0030] The first end faces of the respective friction lining elements 6, projecting axially from the carrier disc 7 on the first side 9 in the direction A, are in frictional contact with the first side part 11, more precisely with the surface of the first side part 11 facing the first side 9 of the carrier disc 7. Furthermore, the second end faces of the respective friction lining elements 6, projecting axially from the carrier disc 7 on the second side 10 in the direction A, are in frictional contact with another friction partner, more precisely with the surface of the other friction partner facing the second side 10 of the carrier disc 7. In the illustrated embodiment, the other friction partner is a disc spring 13, i.e., the surface of the disc spring 13 facing the second side 10 of the carrier disc 7, which is hereinafter also referred to as the second side 15 of the disc spring 13.The second side 15 of the disc spring 13 has a flat contact area 16 which is in frictional contact with a counter-contact area 17 formed by the second end faces of the respective friction lining elements 6.
[0031] Via a first side 14 of the disc spring 13, which is opposite the second side 15 of the disc spring 13 in axial direction A, i.e. pointing away from the carrier disc 7, the disc spring 13 is preferably supported on the second side part 12 on a smaller radius than the radius on which the contact area 16 is formed and is pre-tensioned in axial direction A in such a way that the first end faces of the respective friction lining elements 6 are also brought into frictional contact with the first side part 11, more precisely with the surface of the first side part 11 facing the first side 9 of the carrier disc 7.
[0032] Although not shown, it is also possible that the disc spring 13 does not act directly on the friction lining elements 6, but rather that a pressure plate is arranged in axial direction A between the second end faces of the respective friction lining elements 6 and the second side 15 of the disc spring 13. This pressure plate forms a contact area 16 which is in frictional contact with a counter-contact area 17 formed by the second end faces of the respective friction lining elements 6, and which is acted upon by the disc spring 13 in axial direction A. In this case, the disc spring 13 acts indirectly on the friction lining elements 6.
[0033] In summary, the side parts 11, 12 are arranged on opposite sides 9, 10 of the carrier disc 7. The disc spring 13 presses the first side part 11 frictionally against the first end faces of the friction lining elements 6. Furthermore, the disc spring 13 bears directly against the second end faces of the friction lining elements 6, which are opposite the first end faces in axial direction A, or acts on them indirectly via a pressure plate.
[0034] With reference to Figure 3, the ratio of the thickness 19 of each friction lining element 6, measured in the axial direction A between the two end faces of each element 6, to the thickness 20 of the carrier disc 7, measured in the axial direction A, is greater than 1.05. Furthermore, this ratio is preferably less than 2, and is particularly in the range of 1.5. Specifically, this means that the friction lining elements 6 are approximately 50 percent thicker than the carrier disc 7, through whose openings 8 they extend in the axial direction A. It is self-evident that this ratio is realized particularly in the new condition of the torque limiter 1.
[0035] In the illustrated embodiment, each of the friction lining elements 6 is circular when viewed in the axial direction A. The extent 21 of each of the friction lining elements 6 in the radial direction R is equal to the extent 22 of each of the friction lining elements 6 in the tangential direction T of the torque limiter 1.
[0036] In an embodiment not shown, it is also possible for each of the friction lining elements 6 to have an oval base when viewed in the axial direction A. Likewise, in another embodiment not shown, it is also possible for each of the friction lining elements 6 to be elliptical when viewed in the axial direction A. In summary, it is therefore particularly advantageous if each of the friction lining elements 6 is convex when viewed in the axial direction A.
[0037] The ratio of the radial extent 21 of each of the friction lining elements 6 to the thickness 20 of the carrier disc 7 should be less than 20. Exceeding this limit would require either a very thin carrier disc 7 or a very large amount of installation space in the radial direction R.
[0038] With regard to the embodiment shown in Figures 4 and 5, each of the friction lining elements 6 has a square base area when viewed in the axial direction A. The extent 21 of each of the friction lining elements 6 in the radial direction R is equal to the extent 22 of each of the friction lining elements 6 in the tangential direction T of the torque limiter 1.
[0039] In the embodiment shown in Figures 6 and 7, each of the friction lining elements 6 has a rectangular base when viewed in the axial direction A. It is possible that the extent 21 of each of the friction lining elements 6 in the radial direction R is greater than the extent 22 of each of the friction lining elements 6 in the tangential direction T.
[0040] This variant is used when there is ample installation space in the radial direction R. The radial contact cross-section between the carrier disc 7 and the friction lining elements 6 is relevant for the mechanical stress on the friction lining elements 6 under torque load. With the largest possible width, a smaller material thickness of the carrier disc 7 can be achieved, while the radial contact cross-section remains constant.
[0041] The ratio of the radial extent 21 to the tangential extent 22 is less than 3 in this case. Outside this range, this would either lead to very narrow (tangentially) friction lining elements 6, which are no longer manufacturable, or to a very large installation space requirement in the radial direction R.
[0042] In an embodiment not shown, it is also possible that the extent 22 of each of the friction lining elements 6 in the tangential direction T is greater than the extent 21 of each of the friction lining elements 6 in the radial direction R.
[0043] This variant is used when there is little installation space available in the radial direction R. In this case, the ratio of the extent 22 in the tangential direction T to the extent 21 in the radial direction R is less than 10. Outside this range, this would either lead to (radially) very narrow friction lining elements 6, which are no longer manufacturable, or to a large number of friction lining elements 6 in order to transmit the required torque. The preceding embodiments relate to a torque limiter.
[0044] 1 for a hybrid powertrain of a motor vehicle, with an input-side carrier disc 7, which has openings 8 distributed in the circumferential direction U of the torque limiter 1, into which friction lining elements 6 are positively engaged, with two side parts 11, 12 arranged opposite each other on sides 9, 10 of the carrier disc 7, and with a disc spring 13 pressing a first of these side parts 11, 12 frictionally against first end faces of the friction lining elements 6, wherein the disc spring 13 bears directly against second end faces of the friction lining elements 6 opposite the first end faces in the axial direction A of the torque limiter 1 or acts indirectly on them via a pressure plate, wherein a ratio of the thickness 19 of the friction lining element 6 measured in the axial direction A between the two end faces of a respective friction lining element 6 to a thickness 20 of the Carrier disc 7 larger than 1 ,05 is.,
[0045] List of reference signs
[0046] 1 Torque limiter
[0047] 2 Entrance
[0048] 3 Slip clutch unit
[0049] 4 Exit
[0050] 5 Torsional vibration damper unit
[0051] 6 Friction lining element
[0052] 7 Carrier disc
[0053] 8 Breakthrough
[0054] 9 first side of the carrier disc
[0055] 10 second side of the carrier disc
[0056] 11 first side panel
[0057] 12 second side panel
[0058] 13 Belleville washers
[0059] 14 first side of the disc spring
[0060] 15 second side of the disc spring
[0061] 16 Contact area
[0062] 17 Counter-contact area
[0063] 18 spring element
[0064] 19 Thickness of the friction lining element
[0065] 20 Thickness of the carrier disc
[0066] 21. Radial extension
[0067] 22 Extension in tangential direction
[0068] A axial direction
[0069] D axis of rotation
[0070] R radial direction
[0071] T tangential direction
[0072] U circumferential direction
Claims
Patent claims 1. Torque limiter (1) for a hybrid powertrain of a motor vehicle, comprising an input-side carrier disc (7) having openings (8) distributed in the circumferential direction (U) of the torque limiter (1), into which friction lining elements (6) are positively engaged, with two side parts (11, 12) arranged opposite each other on opposite sides (9, 10) of the carrier disc (7), and with a disc spring (13) pressing a first of these side parts (11, 12) frictionally against first end faces of the friction lining elements (6), wherein the disc spring (13) bears directly against second end faces of the friction lining elements (6) opposite the first end faces in the axial direction (A) of the torque limiter (1), or acts indirectly on them via a pressure plate.wherein the ratio of the thickness (19) of the friction lining element (6) measured in the axial direction (A) between the two end faces of a respective friction lining element (6) to the thickness (20) of the carrier disc (7) measured in the axial direction (A) is greater than 1.
05.
2. Torque limiter (1 ) according to claim 1 , wherein the ratio is less than 2.
3. Torque limiter (1 ) according to claim 1 or 2, wherein the ratio is in the range of 1.
5.
4. Torque limiter (1 ) according to one of claims 1 to 3, wherein an extent (21 ) of each of the friction lining elements (6) in the radial direction (R) of the torque limiter (1 ) is greater than an extent (22) of each of the friction lining elements (6) in the tangential direction (T) of the torque limiter (1 ).
5. Torque limiter (1 ) according to one of claims 1 to 4, wherein each of the friction lining elements (6) has a rectangular base area when viewed in the axial direction (A).
6. Torque limiter (1) according to claim 5, wherein each of the friction lining elements (6) has a square base area when viewed in the axial direction (A).
7. Torque limiter (1) according to any one of claims 1 to 4, wherein each of the The friction lining elements (6) are convex when viewed in the axial direction (A).
8. Torque limiter (1 ) according to claim 7, wherein each of the friction lining elements (6) has an oval base surface when viewed in the axial direction (A).
9. Torque limiter (1 ) according to claim 7, wherein each of the friction lining elements (6) is circular when viewed in the axial direction (A).
10. Torque limiter (1 ) according to claim 7, wherein each of the friction lining elements (6) is elliptically shaped when viewed in the axial direction (A).