Gear mechanism for motor vehicles
09631681 · 2017-04-25
Assignee
Inventors
- Ralph S. Walker (Livonia, MI, US)
- Andreas Tissot (Remscheid, DE)
- Shawn A. Holland (Livonia, MI, US)
- Johann Kirchhoffer (Köln, DE)
Cpc classification
F16D13/64
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Y02T10/60
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F16D21/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D21/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D2021/0615
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D2013/642
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F16D21/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D21/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A gear mechanism for motor vehicles includes a double clutch gear mechanism with two part gear mechanisms and a double clutch which transmits torque from the engine optionally to one of the two part gear mechanisms, with a central disk connected to a drive disk, two outer pressure application plates which are also connected to the drive disk and are moveable in the axial direction relative to the central disk, and friction disks arranged between the central disk and the pressure application plates, wherein the friction disks consist of two support carrier disks arranged parallel to each other and moveably in relation to each other, between which leaf-like spring segments are provided. To eliminate vibration problems which can occur on start-up from standstill, on load-change processes and during the gear change, the leaf-like spring segments have different spring characteristic curves with which a multistage spring characteristic is achieved.
Claims
1. A gear mechanism for motor vehicles, comprising: a double clutch gear mechanism including two part gear mechanisms and a double clutch, which transmits torque from an engine alternately to each of the two part gear mechanisms; a central disk connected to a drive disk; outer pressure application plates connected to the drive disk and moveable axially relative to the central disk; friction disks arranged between the central disk and the pressure application plates, wherein each of the friction disks includes two support carrier disks arranged parallel to each other and moveably in relation to each other, between which non-planar spring segments are located, wherein the spring segments have different spring characteristics for producing a multistage spring characteristic via plate bending of the spring segments.
2. The gear mechanism as claimed in claim 1, wherein the spring segments include a plurality of undulating steel plates, each plate having a different plate thickness and a different spring characteristic.
3. The gear mechanism as claimed in claim 1, wherein the spring segments combined have a progressive characteristic curve.
4. The gear mechanism as claimed in claim 1, wherein the spring segments are formed as pairs of conjoined springs connected in series and having different characteristic curves.
5. The gear mechanism as claimed in claim 4, wherein the spring segments are formed alternately as the pairs of conjoined springs and single springs.
6. The gear mechanism as claimed in claim 1, wherein the spring segments are formed as pairs of conjoined springs connected in parallel and having different characteristic curves.
7. The gear mechanism as claimed in claim 1, wherein the spring segments are secured to the support carrier disks by rivets.
8. The gear mechanism as claimed in claim 1, wherein a carrier plate is arranged between one of the support carrier disks and one of the spring segments.
9. The gear mechanism as claimed in claim 1, further comprising, one active drive train and one passive drive train according to a respective gear that is engaged, wherein the passive drive train is provided with gear rattle damping.
10. A gear mechanism for motor vehicles, comprising: a double clutch gear mechanism including two part gear mechanisms and a double clutch, which transmits torque from an engine alternately to each of the two part gear mechanisms; a central disk connected to a drive disk; outer pressure application plates connected to the drive disk and moveable axially relative to the central disk; friction disks arranged between the central disk and the pressure application plates, wherein each of the friction disks includes two support carrier disks arranged parallel to each other and moveably in relation to each other, between which bent plate spring segments are located, wherein the spring segments have different spring characteristics for producing a multistage spring characteristic via plate bending of the spring segments, wherein the spring segments are secured to the support carrier disks by rivets.
Description
DESCRIPTION OF THE DRAWINGS
(1) The invention will be more readily understood by reference to the following description, taken with the accompanying drawings, in which:
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DESCRIPTION OF THE PREFERRED EMBODIMENT
(24) According to
(25) The drive disk 2 sits rotationally fixed on an input shaft 8 of the double clutch 1 and consequently rotates therewith at the same rotation speed. The input shaft 8 is normally the driveshaft or crankshaft of an engine not shown in the drawing.
(26) The drive disk 2 is connected to the central disk 3 via a clutch body 13, i.e. the central disk 3 rotates with the same rotation speed as the drive disk 2. The pressure application plates 4 and 5 arranged on both sides of the central disk 3 rotate with the central disk 3 but are however moveable axially in relation to the central disk 3. The central disk 3 is supported axially via a clutch bearing 19 and a cardanic thrust washer 16 and a cardanic coupling 15 on a hollow shaft 11 leading to the gear mechanism, and is radially free-running.
(27) To trigger the coupling process, one of the pressure application plates 4 and 5 is moved in the direction of the central disk 3, whereby the respective friction disk 6 or 7 is pressed firmly against the central disk 3.
(28) By the coupling of the respective friction disk 6 or 7, this rotates with the central disk 3 and transmits the engine torque to the respective output shaft 11 or 12 of the double clutch 1 leading to the gear mechanism.
(29) The output shaft 12, which can be connected to the friction disk 6 shown on the left in the drawing, is formed as a solid shaft and, like the output shaft 11, opens into a gear mechanism housing not shown in the drawing, where it serves to drive a first part gear mechanism. This first part gear mechanism for example serves gears 1, 3 and 5.
(30) The output shaft 11, which can be connected to the friction disk 7 shown on the right in the drawing, as a hollow shaft surrounds the solid shaft 12 and also leads into the gear mechanism housing not shown in the drawing. It serves to drive a second part gear mechanism, which for example is provided for gears 2, 4, 6 and R.
(31) The output shafts 11 and 12 are each connected by form fit, via a notched toothing 20 or 21, to the friction disks 6 and 7 via damping systems 10 and 24.
(32) The entire double clutch 1 shown in
(33) According to
(34) In the double clutch 18 shown in
(35) The respective friction disks 6 and 7 are coupled and decoupled in the same way as in the exemplary embodiment shown in
(36) In contrast to the embodiment shown in
(37) The exemplary embodiment shown in
(38) The embodiment shown in
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(40) These friction disk systems are fitted with a clutch lining 25 and connected by means of lining rivets 26 to the spring segments 27, which in turn are connected via segment rivets 28 to the drive carrier disk 29. The drive carrier disk 29 has a hub 30 with an internal notched toothing which is formed integrally with the drive carrier disk 29 or can be connected thereto via a rivet connection.
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(42) Four different lining spring systems are known from the prior art: 1) One-stage lining characteristic, single or one-segment system:
(43) The coupling capacity is determined by the following formula:
Mk=Fa*Mu*Rm*z
where: Mk=coupling moment Fa=pressure application force Mu=coefficient of friction Rm=mean friction radius Z=number of friction surfaces
(44) The pressure application force arises from the resulting spring rates connected in series, multiplied by the spring travel when the clutch is pressed. In the medium and low torque regions, the clutch lining spring dominates the pressure application force characteristic. This is shown as an example in
(45) A lining spring characteristic curve shows as an example the very small spring travel band in which very high pressure application forces can be generated. If a high variability in the friction values is added, a high and also highly variable transmission function results with a high torque spread of the clutch.
(46) This effect is shown in
(47) To solve these problems, according to the invention a lining characteristic with at least two stages, up to four stages, is provided. This is depicted in
(48) The following lining spring characteristics or stages are provided: A) phase of gear rattle damping B) clutch bite point and creep control C) part-load range D) full-load range
(49) With regard to the lining spring travel, the following feature combinations are proposed: a) The lining spring travel is extended by around 0.5 mm compared with conventional lining spring travels. This is possible since modern friction linings are substantially more wear-resistant. b) A gear rattle damping phase 63 is introduced in order to allow the introduction of an electronically controlled gear rattle prevention or damping system, namely for a region from 1 Nm to 5 Nm. The spring travel proposed here is 0.5 mm but this can also be varied. c) A bite point and creep coupling moment phase 64 of 5 Nm to 25 Nm is proposed, within a lining spring travel of around 0.3 mm. d) A part-load/start-up and operation phase 67 is introduced which is provided for operations over around 25 Nm to 50 Nm/120 Nm. e) A full-load/start-up and operation phase 65 is introduced which is provided for coupling moments greater than around 120 Nm up to the end of the lining spring travel of the system at around 1.3 mm.
(50) This entire characteristic cannot be achieved by a single lining spring characteristic curve but at least two or more spring characteristics are required. For this springs can be used in parallel connection or in series connection.
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(52) Preferably multistage solutions are used, as shown for example in
(53) Any individual total spring characteristic curve can be achieved in the same way with lining springs which are arranged in series or parallel connection. It is also possible to combine a series and parallel connection of the lining springs.
(54) Different detailed solutions are described below which lead to a two- or multistage lining spring characteristic:
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(58) In parallel to the first double segment variant, a second double segment variant is connected at a distance, in which the one element 69 has a third spring rate and the other segment 70 a fourth spring rate.
(59) Both double segment variants are equipped with a stop, wherein the weaker spring characteristic curve is switched to mass in each case. When the two clutch linings are pressed together, both spring rates of lining springs 50 and 51 are then applied directly, and at a distance 45, then the lining springs 69 and 70.
(60) Such a variant can be achieved with in total at least eight double segments, i.e. four with a distance and the first and second spring rates, and four without a distance with the third and fourth spring rates. Similarly, a 3/6 or 5/10 solution is possible.
(61) The lining springs are then positioned to guarantee a right-angled, parallel and stable position of the clutch linings. The double segments are then either integrated in or riveted by force fit to the drive carrier disk 28.
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(63) The spring characteristics are here as follows: Stage 1: C-Stage 1=C1*C2/(C1+C2) Stage 2: C-Stage 2=C1*C2/(C1+C2)+C3*C4/(C3+C4) Stage 3: (Stop C1/C2):C-Stage 3=C2+C3*C4/(C3+C4) Stage 4: (Stop C3/C4):C-Stage 4=C2+C4
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(65) This arrangement can be achieved with a total of at least three single and double segments in a 3/6 or 4/8 configuration. The lining springs should then be positioned to guarantee a right-angled, parallel and stable position of the clutch linings. The single segments can either be integrated in or connected by force fit to the drive carrier disk 28.
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(67) The spring characteristics are here as follows: Stage 1: C-Stage 1=C1*C2/(C1+C2) Stage 2: C-Stage 2=C1*C2/(C1+C2)+C3 Stage 3 (Stop C1/C2): C-Stage 3=C2+C3
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(73) The lining springs are then positioned to guarantee a right-angled, parallel and stable position of the clutch linings. The single segments can either be integrated in or riveted by force fit to the drive carrier disk 28.
(74) With reference to
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(76) Scenario 1: The passive path is pre synchronized.
(77) In this case the clutch builds up a counter-moment and clamps the presynchronized gear wheels against each other, so they can no longer cause gear rattle. The other loose gear wheels are then given a corresponding differential rotation speed via the engaged second clutch 56, which in turn generates a damping on the non-presynchronized gear wheel and thus damps the gear rattle.
(78) Scenario 2: The passive path is not presynchronized.
(79) In this case application of the passive clutch generates a rotation speed difference between the loose gear wheels and the passive input shaft, which leads to a damping of gear rattle.
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(81) The use of the passive part gear mechanism as damper for the loose gear wheels described above is in principle also applicable to double dry gear mechanisms and double wet gear mechanisms. The basic requirement for such an application is that the passive path is always held under slip control and hence the passive path is shielded from engine torque irregularities. This is possible only if the coupling moment can be set precisely in the region from around 1 Nm to 10 Nm. The invention described here of the two- or multistage lining spring as a solution for gear rattle damping is indispensable.
LIST OF REFERENCE NUMERALS
(82) 1 Double clutch/system 1 2 Drive disk 3 Central disk 4 Pressure application plate 5 Pressure application plate 6 Friction disk 7 Friction disk 8 Input shaft 9 Torsion damper 10 Torsion damper 11 Output shaft (hollow shaft) 12 Output shaft (solid shaft) 13 Clutch body 1 14 Clutch body 2 15 Cardanic coupling of central disk 16 Cardanic thrust washer 17 Central disk mounted on hollow shaft 11 18 Double clutch/system 2 19 Clutch bearing 20 Notched toothingclutch 1 21 Notched toothingclutch 2 22 Pilot bearing 23 Bearing system/hollow shaft/solid shaft 24 Torsion damper 25 Clutch lining 26 Lining rivet 27 Spring segment 1 28 Segment rivet, drive carrier disk 29 Drive carrier disk 30 Hub 31 Single segment 32 Double segment 33 Segment lining rivet 34 Spring segment 2 35 Single disk spring segment 36 Premounted lining spring/drive carrier disk system 37 Spring rivet 38 Phasecreep control 39 Phaselow torque transmission 40 Phasehigh torque transmission 41 Single lining spring characteristic 1 42 Single lining spring characteristic 2 43 Lining spring characteristic 1+2 overlaid 44 Standard lining spring characteristic 45 Distance of lining spring 1 from lining spring 2 46 Lining spring 1 47 Lining spring 2 48 Clutch lining integrated in a steel disk 49 Lining rivet 2 50 Double lining spring characteristic 1 51 Double lining spring characteristic 2 52 Double leaf lining spring 53 Segment rivet 54 Double segment spring with two spring characteristics 55 Clutch 1 56 Clutch 2 57 Engine rotation speed 58 Part gear mechanism 1 59 Part gear mechanism 2 60 Active drive train 61 Passive drive train 62 Output shaft rotation speed 63 Gear rattle damping phase 64 Creep coupling moment phase 65 Start-up moment phase 66 Carrier plate 67 Part-load phase 68 Second double segment design 69 Double segment spring characteristic 3 70 Double segment spring characteristic 4
(83) In accordance with the provisions of the patent statutes, the preferred embodiment has been described. However, it should be noted that the alternate embodiments can be practiced otherwise than as specifically illustrated and described.