Disk, Disk Clutch with Such a Disk, Double Clutch Device with Such a Disk Clutch, and Method for Producing a Disk

Abstract

The present invention relates to a disk (38) for a disk clutch (26) comprising an annular base element (76) which has a toothing (78) with multiple teeth (80) for achieving a rotary driving engagement with a disk carrier (34), wherein the base element (76) has at least one hardened region (96) in which the base element (76) is designed as harder than in the tooth flank regions (98, 100) of the teeth (80). In addition, the present invention relates to a disk clutch (26) with such a disk (38), a double clutch device (2) with such a disk clutch (26), and a method for producing such a disk (38).

Claims

1. A disk (38) for a disk clutch (26) comprising an annular base element (76) which has a toothing (78) with multiple teeth (80) for achieving a rotary driving engagement with a disk carrier (34), characterized in that the base element (76) has at least one hardened region (96) in which the base element (76) is designed as harder than in the tooth flank regions (98, 100) of the teeth (80).

2. The disk (38) according to claim 1, characterized in that the hardened region (96) is arranged at a distance (b) to the tooth flanks (90, 92) of the teeth (80), wherein the distance (b) is preferably at least 3 mm.

3. The disk (38) according to claim 1, characterized in that the hardened region (96) is arranged in a distance (a) to the tooth roots of the teeth (80), wherein the distance (a) is preferably at least 3 mm, and/or the teeth (80) are hardened to achieve a lower hardness than in the hardened region (96) or are unhardened in contrast to the hardened region (96).

4. The disk (38) according to claim 1, characterized in that the hardened region (96) is designed to extend, if necessary, continuously in circumferential direction (12, 14) on a front side and/or back side of the base element (76), wherein the hardened region (96) extends in radial direction (8) preferably up to a delimitation circle (102) which is arranged particularly preferably at a distance (a) in the same radial direction (8) to a tooth root circle (104) of the teeth (80), which is, if necessary, at least 3 mm.

5. The disk (38) according to claim 4, characterized in that the distance (a) between the delimitation circle (102) and the tooth root circle (104) is a maximum of 5 mm, particularly a maximum of 4 mm, particularly preferably a maximum of 3.5 mm.

6. The disk (38) according to claim 1, characterized in that the toothing (78) is an external toothing, and/or the base element (76) is manufactured or made from metal or steel, and/or the disk (38) is designed as a disk (38) without a friction lining, and/or is designed as a steel disk.

7. The disk (38) according to claim 1, characterized in that the base element (76) is surface hardened in the hardened region (96), preferably using gas nitriding or gas nitrocarburizing or using plasma nitriding or plasma nitrocarburizing.

8. A disk clutch (26) with at least one disk (38) according to claim 1, wherein the disk (38) is preferably in rotary driving engagement via the toothing (78) with a disk carrier (34), which is softer (78) than the base element (76) in the hardened region (96), or has essentially the same hardness as the tooth flank region (98, 100), and is particularly preferably not hardened and/or not nitrided or nitrocarburized.

9. A double clutch device (2) for arranging in a drivetrain between a drive unit (18) and a transmission (20), having a first disk clutch (26) assigned to a first transmission input shaft (22) for selective torque transmission between the drive unit (18) and the first transmission input shaft (22) and a second disk clutch (28) assigned to a second transmission input shaft (24) for selective torque transmission between the drive unit (18) and the second transmission input shaft (24), characterized in that the first and/or second disk clutch (26; 28), preferably only one of the two disk clutches (26, 28), particularly preferably only the radially outer disk clutch (26) of the double clutch device (2) designed as a concentric double clutch device (2), is designed as a disk clutch (26) according to claim 8.

10. A method for producing a disk (38) according claim 1 comprising the method steps: providing an annular base element (76) which has a toothing (78), preferably an external toothing, with multiple teeth (80), covering at least the tooth flank regions (98, 100) of the toothing (78), preferably completely covering the teeth (80) of the toothing (78), particularly preferably creating a covered safety margin (106) between the teeth (80) and an uncovered region of the base element (76), and surface hardening the base element (76) using gas nitriding or gas nitrocarburizing or using plasma nitriding or plasma nitrocarburizing to create at least one hardened region (96), in which the base element (76) is designed as harder than in the tooth flank regions (98, 100) of the toothing (78), preferably harder than in the region of the teeth (80), particularly preferably harder than in the region of the teeth (80) and the safety margin (106).

Description

[0028] The invention will subsequently be explained in more detail by means of exemplary embodiments with reference to the accompanying drawings. As shown in:

[0029] FIG. 1 a partial side view of a double clutch device with a first and a second disk clutch in a cutaway view,

[0030] FIG. 2 a front view of a disk from the first disk clutch from FIG. 1 in a first embodiment variant,

[0031] FIG. 3 a partial front view of the disk from the first disk clutch from FIG. 1 in a second embodiment variant, and

[0032] FIG. 4 a partial front view of the disk from FIG. 1 in a third embodiment variant.

[0033] FIG. 1 shows a double clutch device 2. In FIG. 1, opposite axial directions 4, 6, opposite radial directions 8, 10, and opposite circumferential directions 12, 14 of double clutch device 2 are indicated by means of corresponding arrows, wherein double clutch device 2 is rotatable about an axis of rotation 16 which extends in axial directions 4, 6.

[0034] Double clutch device 2 is arranged in axial directions 4, 6 between a drive unit 18, thus, for example, an internal combustion engine, and a transmission 20, which are essentially schematically indicated in FIG. 1, wherein a first transmission input shaft 22 and a second transmission input shaft 24 are also indicated for transmission 20, of the two, first transmission input shaft 22 extends in axial direction 4, 6 through second transmission input shaft 24, which is designed as a hollow shaft for this purpose.

[0035] Double clutch device 2 has a first disk clutch 26 and a second disk clutch 28, wherein double clutch device 2 is designed as a concentric double clutch device 2 so that first disk clutch 26 or its disk set 30 surrounds second disk clutch 28 or its disk set 32 outwardly in radial direction 8, and first disk clutch 26 may be called the radially outer disk clutch and second disk clutch 28 may be called the radially inner disk clutch.

[0036] First disk clutch 26 has a first disk carrier 34, in this case an input side outer disk carrier, and a second disk carrier 36, in this case an output side inner disk carrier, which are assigned to disk set 30 of first disk clutch 26. Thus, disk set 30 has first disks 38, in this case outer disks, which are in rotary driving engagement with first disk carrier 34, however, are displaceable relative to the same in axial direction 4, 6, and second disks 40, in this case inner disks, which are in rotary driving engagement with second disk carrier 36, however, are likewise displaceable in axial direction 4, 6 relative to second disk carrier 36. First disks 38 are thereby arranged alternating with second disks 40 in axial direction 4, 6, wherein first disks 38 are designed as disks 38 without friction linings, while second disks 40 are designed as friction lining disks which are essentially composed from a friction lining carrier 42 and friction linings 44, 46 fixed on both sides on friction lining carrier 42.

[0037] Correspondingly, second disk clutch 28 also has a first disk carrier 48 designed as an outer disk carrier which functions as the input side, a second disk carrier 50 designed as an inner disk carrier which functions as the output side, and disk set 32 composed of first and second disks 52, 54, of which first disks 52 are designed as outer disks without friction linings and second disks 54 are designed as friction lining disks with friction lining carrier 56 and friction linings 58, 60.

[0038] As is clear from FIG. 1, first disk clutch 26 functions for selective torque transmission between drive unit 18 and first transmission input shaft 22 of transmission 20, while second disk clutch 28 functions for selective torque transmission between drive unit 18 and second transmission input shaft 24. For this purpose, double clutch device 2 has a clutch input hub 62, which is in rotary driving connection with first disk carrier 34 of first disk clutch 26 via a drive plate 64. First disk carrier 34 of first disk clutch 26 is additionally connected rotationally fixed to a clutch hub 66, to which first disk carrier 48 of second disk clutch 28 is also connected rotationally fixed, wherein clutch hub 66 functions to support double clutch device 2 in radial direction 8, 10 on a housing of transmission 20, not shown in greater detail. The two disk clutches 26, 28 are hydraulically actuatable and/or designed as wet-running.

[0039] The two first disk carriers 34, 48 of the two disk clutches 26, 28 are designed as shaped sheet metal parts, wherein these each have an essentially tubular disk support section 68, 70 extending in axial directions 4, 6 with a rotary driving contour for achieving a rotary driving engagement with first disks 38 or 52 and a support section 72 or 74 extending in axial direction 6 to disk support section 68, 70 and up to clutch hub 66 in radial direction 10. Support sections 72, 74 are connected inward in radial direction 10as previously mentionedto clutch hub 66 in a rotationally fixed way, wherein support sections 72, 74 are preferably welded to clutch hub 66.

[0040] FIG. 2 shows a front view of one of first disks 38 of first disk clutch 26, wherein the subsequent description of first disk 38 applies equally for all first disks 38 of first disk clutch 26. Disk 38 has an annular base element 76 which has a toothing 78 with multiple teeth 80 for achieving a rotary driving engagement with first disk carrier 34, stated more precisely, with disk support section 68 of first disk carrier 34. Toothing 78 is designed as an external toothing with teeth 80 projecting outward in radial direction 8, wherein teeth 80 are arranged following one another in circumferential direction 12, 14 to form interdental spaces 82, wherein a uniform distribution of teeth 80 on annular base element 76 in circumferential direction 12, 14 is preferred. Teeth 80 are preferably designed as one piece with annular base element 76. Annular base element 76 is manufactured from metal or steel or is made from metal or steel so that disks 38 may also be designated as metal or steel disks.

[0041] Annular base element 76 has an inside edge 84 facing inward in radial direction 10 and an outside edge 86 facing outward in radial direction 8, wherein inside edge 84 is essentially designed as a circular shape, while outside edge 86 is formed by tooth tips 88 and tooth flanks 90, 92 of teeth 80 and bottoms 94 of interdental spaces 82.

[0042] Base element 76 has a hardened region 96 on the side facing in axial direction 4, wherein hardened region 96 is surface hardened and thus may also be designated as surface hardened region 96. Hardened region 96 is surface hardened using gas nitriding or gas nitrocarburizing or, particularly preferably, using plasma nitriding or plasma nitrocarburizing. Base element 76 is thereby designed to be harder in hardened region 96 than in the tooth flank regions 98, 100 assigned to tooth flanks 90, 92 of teeth 80.

[0043] In the first embodiment variant according to FIG. 2, hardened region 96 is designed as continuously extending in circumferential direction 12, 14 on the front side of base element 76 facing in axial direction 4. Hardened region 96 thereby extends inward in radial direction 10 up to inside edge 84 of annular base element 76 and outward in radial direction 8 up to delimitation circle 102, indicated by a dashed line. Delimitation circle 102 is arranged preferably concentric to axis of rotation 16 of base element 76. Delimitation circle 102 is arranged at a distance a to a tooth root circle 104 of teeth 80, indicated by a dashed line in the same outward radial direction 8, wherein tooth root circle 104 and delimitation circle 102 are preferably arranged concentric to one another. Tooth root circle 104 consequently has a greater radius that delimitation circle 102, wherein the radius of tooth root circle 104 is greater by distance a, which is at least 3 mm. Due to this distance a, an annular safety margin 106 is created between delimitation circle 102 and tooth root circle 104, said safety margin may indeed by influenced in its material properties by the targeted surface hardening of hardened region 96; however, due to minimum distance a of 3 mm, it ensures that tooth flank regions 98, 100 are largely uninfluenced, and are thus designed as correspondingly soft to be able to interact with first disk carrier 34 without wear. The surface hardening of hardened region 96 using gas nitriding or gas nitrocarburizing, in particular using plasma nitriding or plasma nitrocarburizing, has the advantage hereby that the influencing of safety margin 106 is relatively low, so that distance a does not have to significantly exceed said minimum distance of 3 mm. Thus, in said method for hardening the surface, is has proven sufficient if distance a between delimitation circle 102 and tooth root circle 104 is a maximum of 5 mm, preferably a maximum of 4 mm, particularly preferably a maximum of 3.5 mm in order to situate hardened region 96 with its advantages relatively close to teeth 80 without thereby negatively influencing tooth flank regions 98, 100. Thus, a particularly compact structure is achieved by this means for annular base element 76 and disk 38 formed therefrom. In the first embodiment variant according to FIG. 2, teeth 80 are designed as unhardened in contrast to hardened region 96 or are designed as hardened to achieve a lower hardness than in hardened region 96. Thus, teeth 80 may, for example, simply have the height of the base material of base element 76.

[0044] One embodiment variant deviating from the first embodiment variant from FIG. 2 is depicted in FIG. 3, wherein subsequently only the differences from the first embodiment variant will be discussed: identical reference numerals are used for identical or similar parts and otherwise the previous description correspondingly applies.

[0045] In contrast to the first embodiment variant according to FIG. 2, hardened region 96 is formed at least partially also in the area of teeth 80, so that hardened region 96 is no longer outwardly delimited in radial direction 8 as a circular shape, but instead by the delimitation line 108 indicated in FIG. 3 by a dotted line. Delimitation line 108 is thereby selected in such a way that hardened region 96 is arranged at a distance b to tooth flanks 90, 92 of teeth 80, wherein distance b is at least 3 mm. This distance b is also provided to bottoms 94 of interdental spaces 82 in the second embodiment variant according to FIG. 3. By maintaining said distances b from tooth flanks 90, 92 and bottoms 94 of interdental spaces 82, hardened region 96 may, however, extend through up to tooth tips 88 of teeth 80 in order to achieve a greatest hardening with the known advantages.

[0046] FIG. 4 shows a third embodiment variant of disk 38, which essentially corresponds to the second embodiment variant according to FIG. 3, so that subsequently only the differences shall be addressed; identical reference numerals are used for identical or similar parts and otherwise the previous description correspondingly applies.

[0047] In contrast to the second embodiment variant according to FIG. 3, hardened region 96 is only arranged in a minimum distance b with respect to tooth flanks 90, however, no longer at a distance with respect to bottoms 94 of interdental spaces 82, so that hardened region 96 may also extend up to bottoms 94 of interdental spaces 82 as long as it thereby maintains distance b to tooth flanks 90, 92.

[0048] Regardless of the respectively selected embodiment variant according to FIGS. 2 through 4, the preceding embodiments also apply in an analogous way for the back side of annular base element 76 facing in axial direction 6. In addition, toothing 78 of annular base element 76 engages in first disk clutch 26 to achieve a rotary driving engagement into the rotary driving contour of disk support section 68 of first disk carrier 34, wherein first disk carrier 34 is, at least in a contact region with toothing 78 of disk 38, softer than base element 76 in hardened regions 96, and/or has essentially the same hardness as tooth flank regions 98, 100. It is hereby particularly preferred if first disk carrier 34 is completely unhardened or at least disk support section 68 of first disk carrier 34 is unhardened, and/or is unhardened in contrast to hardened region 96 of disks 38, and/or is not nitrided or is not nitrocarburized. In this way, disks 38 are created which are wear-resistant, counteract noise during operation of first disk clutch 26, and guarantee a low-wear interaction with first disk carrier 34 or its disk support section 68, so that first disk carrier 34 has to be unhardened, or does not have to be nitrided or nitrocarburized, which further simplifies its production, in particular its welding to clutch hub 66.

[0049] Basically, first disks 52 of second disk clutch 28 might also be designed as modified or partially hardened in the way described with reference to FIGS. 2 through 4. However, it has been shown that, for noise reduction within a double clutch device 2, one disk clutch 26; 28 with disks 38 as described already leads to a substantial noise reduction so that corresponding disks 38 do not also have to be provided in second disk clutch 28. Thereby, it is particularly preferredas is shown in FIG. 1if the outer disk clutch in radial direction 8, in this case first disk clutch 26, which has first disks 38 as described with reference to FIGS. 2 through 4, effects a substantial reduction of noise, while conventional metal or steel disks, which are unhardened or not nitrided or nitrocarburized, may be used as first disks 52 for the radially inner disk clutch, in this case second disk clutch 28.

[0050] Within the context of the method for producing disks 38, annular base element 76 with toothing 78, in this case external toothing 78, is initially provided. Subsequently only tooth flank regions 98, 100 (FIG. 4), tooth flank regions 98, 100 and the regions of bottoms 94 of interdental spaces 82 (FIG. 3), or teeth 80 of toothing 78 are completely covered, the latter while creating, if necessary, a covered safety margin 106 between teeth 80 and a not covered region 96 of base element 76 (FIG. 2). Finally, non-covered base element 76 is surface hardened in such a way using gas nitriding or gas nitrocarburizing or plasma nitriding or plasma nitrocarburizing, wherein this is carried out to create the at least one hardened region 96. Base element 76 is thus designed as harder in hardened region 96 than in tooth flank regions 98, 100 of toothing 78 (FIGS. 3 and 4), and harder than in the region of teeth 80 and safety margin 106 (FIG. 2), wherein safety margin 106 functions as a type of transition zone to ensure a soft design of toothing 78. While it is relatively effective for this purpose to apply pastes for covering in the context of gas nitriding or gas nitrocarburizing, these do, however, include an increased manufacturing expense; whereas quite simple and fixed covering means, stencils, or templates may be used during plasma nitriding or plasma nitrocarburizing, which additionally guarantee a particularly safe and reproducible delimitation of hardened region 96.

REFERENCE NUMERALS

[0051] 2 Double clutch device [0052] 4 Axial direction [0053] 6 Axial direction [0054] 8 Radial direction [0055] 10 Radial direction [0056] 12 Circumferential direction [0057] 14 Circumferential direction [0058] 16 Axis of rotation [0059] 18 Drive unit [0060] 20 Transmission [0061] 22 First transmission input shaft [0062] 24 Second transmission input shaft [0063] 26 First disk clutch [0064] 28 Second disk clutch [0065] 30 Disk set [0066] 32 disk set [0067] 34 First disk carrier [0068] 36 Second disk carrier [0069] 38 First disks [0070] 40 Second disks [0071] 42 Friction lining carrier [0072] 44 Friction lining [0073] 46 Friction lining [0074] 48 First disk carrier [0075] 50 Second disk carrier [0076] 52 First disks [0077] 54 Second disks [0078] 56 Friction lining carrier [0079] 58 Friction lining [0080] 60 Friction lining [0081] 62 Clutch input hub [0082] 64 Drive plate [0083] 66 Clutch hub [0084] 68 Disk support section [0085] 70 Disk support section [0086] 72 Support section [0087] 74 Support section [0088] 76 Annular base element [0089] 78 Toothing [0090] 80 Teeth [0091] 82 Interdental spaces [0092] 84 Inside edge [0093] 86 Outside edge [0094] 88 Tooth tips [0095] 90 Tooth flank [0096] 92 Tooth flank [0097] 94 Bottoms [0098] 96 Hardened region [0099] 98 Tooth flank region [0100] 100 Tooth flank region [0101] 102 Delimitation circle [0102] 104 Tooth root circle [0103] 106 Safety margin [0104] 108 Delimitation line [0105] a Distance [0106] b Distance