DE102017127699A1 - torque - Google Patents

Abstract

It is a torque limiter (10) for limiting a torque which can be transmitted in a drive train of a motor vehicle, provided with a transmission flange (12) rotatable about an axis of rotation for transmitting the torque, at least one support disk (14, 16) frictionally engaging the transmission flange (12). for frictionally exchanging the torque with the transmission flange (12) up to a defined limit torque, the transmission flange (12) and the support disk (14, 16) abutting one another in a frictional contact region (24, 26), and at least one of the transmission flange (12 ) and / or from the support disc (14, 16) formed to the Reibkontaktbereich (24, 26) towards the open material recess (28) for receiving a lubricant. By means of the material recess (28) achievable lubrication of the torque limiter (10), a scattering of friction coefficients of the torque limiter (10) can be reduced, so that at a high maximum torque transferable avoidance of excessive torque peaks in a drive train of a motor vehicle is possible ,

Description

The invention relates to a torque limiter, with the aid of which, for example in the manner of a slip clutch, up to a certain limit torque in a drive train of a motor vehicle, a torque can be frictionally transmitted, wherein above the limit torque slipping can take place, the transmission of too large undesirable Torque prevented.

Out DE 10 2015 218 636 A1 is configured as a dual mass flywheel torsional vibration damper, in which a primary mass and a secondary mass are limited rotatable relatively coupled via an arranged in a receiving space bow spring. The secondary mass has a projecting into the receiving space output flange which is connected via a designed as a double-acting friction clutch torque limiter on the remaining secondary mass.

There is a constant need to avoid strong torque peaks in a drive train of a motor vehicle without unnecessarily restricting a maximum transmittable torque.

It is the object of the invention to show measures that allow the avoidance of excessive torque peaks in a drive train of a motor vehicle at a high maximum transmittable torque.

The object is achieved by a torque limiter with the features of claim 1. Preferred embodiments of the invention are set forth in the subclaims and the following description, which may each individually or in combination constitute an aspect of the invention.

According to the invention, a torque limiter for limiting a torque transmissible in a drive train of a motor vehicle is provided with a transmission flange rotatable about a rotation axis for transmitting the torque, at least one frictionally engaging the transmission flange support disk for frictionally replacing the torque with the transmission flange up to a defined limit torque, said the transfer flange and the support disk abut one another in a frictional contact region, and at least one material recess, which is open from the transfer flange and / or from the support disk and opens toward the frictional contact region, for receiving a lubricant.

A sudden impact of an impulse may result in unintentional loads in the powertrain that may result in damage to torque transmitting components in the powertrain. Impacts arise, for example, when stalled when starting the motor vehicle of the motor vehicle engine, a switching takes place, a quick engagement takes place, a downshift with simultaneous gas give done emergency braking takes place, a bang start ("Cavalierstart") takes place or an engine start of the motor vehicle engine , By the torque limiter, a transmission of too high torques can be avoided in the manner of a low-pass filter by the transmission flange can slip on the support disk at too high torque with sliding friction. The maximum torque that can still be transmitted by the torque limiter depends on friction properties, in particular coefficient of friction and contact pressure, between the transmission flange and the support disk in the friction contact region. However, the coefficient of friction of the torque limiter can spread over a certain range, so it is necessary to design the torque limiter for the maximum possible friction value in order to avoid too high torques in the drive train. If the actual coefficient of friction, for example due to wear effects, is less than the coefficient of friction assumed for the design, the maximum torque that can be transmitted by the torque limiter is lowered unnecessarily far.

In the material recess formed by the transmission flange and / or by the support disk, a lubricant, in particular lubricating grease, can be filled, so that the volume of the material recess can be used as a reservoir for receiving the lubricant. Since the material recess is opened to the frictional contact region, the lubricant can enter the frictional contact region and cause lubrication between the transmission flange and the support disk. By lubricating the torque limiter with the lubricant, it is possible to reduce the dispersion of the friction values in the dry state. Instead, the actual coefficient of friction of the lubricated wet torque limiter can be predicted within narrower limits with less dispersion. This makes it possible to predict the maximum transmissible torque with a higher accuracy, whereby an unnecessarily large safety reserve can be reduced. At a higher maximum torque that can be transmitted, excessive torque peaks in the drive train of a motor vehicle can still be safely avoided. About the total volume of the Reibkontaktbereich associated material recesses can be available for the lubrication amount of lubricant be set very precisely, so that in particular for a certain period provided sufficient lubrication can be guaranteed. The achievable with the help of the material recess lubrication of the torque limiter, a scattering of friction coefficients of the torque limiter can be reduced, so that at a high maximum torque transferable avoidance of excessive torque peaks in a drive train of a motor vehicle is possible.

Here, the knowledge is exploited that it is in principle unproblematic if the frictional contact area is smaller by a provided in the transmission flange and / or in the support plate material recess. The size of the friction contact area can be easily adjusted by overlapping the transmission flange with the support disk. The frictional contact area, which has become smaller due to the material recess, can be compensated by a slight enlargement of the overlapping area between the transmission flange and the support disk, with the installation space required for this generally being readily available. Here, a slight increase in the outer diameter of the overlap can cause a disproportionate increase in the frictional contact area. This can be realized by the at least one material recess in the utilization of a given available space, a particularly large total volume, which leads to a particularly good lubrication over a particularly long service life of the torque limiter.

In particular, the torque limiter may have a first support disk and a second support disk, between which the transmission flange is frictionally clamped until the defined limit torque is reached. Above the limit torque, the transmission flange may slip on the first support disk and on the second support disk with sliding friction. Between the first support disk and the transmission flange, a first friction contact region is formed, while a second friction contact region is formed between the second support disk and the transmission flange. In this case, it is possible for the first support disk and the second support disk to have different dimensions in the radial direction. Alternatively, it is also possible that the torque limiter only has exactly one transmission flange and only exactly one support disk, which together form only exactly one friction contact region. Depending on the design of the torque limiter, the term "support disk" is thus understood to mean exactly one support disk or the first support disk and / or the second support disk. Correspondingly, the term "friction contact region" is understood to mean, depending on the design of the torque limiter, exactly one friction contact region or the first friction contact region and / or the second friction contact region. The first support disk and the second support disk can in particular, for example, via a riveted joint, be connected to each other, preferably via the same connecting element another component, such as an output element, via which the torque can be passed in torque flow, can be connected. In addition, a sealing membrane can be connected via the same connecting element, which can seal a receiving space of a dual-mass flywheel.

In particular, at least one material recess extends over a limited peripheral area. The material recess can, for example, have a circular opening cross section in the plane of the friction contact region. The lubricant provided in the material recess can be dispensed in the radius region of the material recess and be taken along by the material of the transmission flange and / or the support disk provided in the same radius region. Material transport in the radial direction is not required for the lubricant. Preferably, a plurality of separate radially offset material recesses are provided, which in their entirety can cover and lubricate a majority of the radial extent, preferably the entire radial extent, of the friction contact area.

Preferably, the material recess is formed as a passage opening. The easily made for example by punching or drilling material recess can extend over the entire material thickness of the transmission flange or the support disk. The volume of the material recess can provide a large volume for receiving a correspondingly large amount of lubricant with a comparatively small areal extent at the friction contact area. Preferably, the material recess has a substantially funnel-shaped course in the axial direction, so that the material recess on the friction contact region can have a different cross-sectional area than on the axial side facing away from the friction contact region. If the cross-sectional area of the material recess is smaller at the axial side facing away from the frictional contact region than at the frictional contact region, the lubricant can be retained more easily in the material recess without running out on the axial side pointing away from the frictional contact region. If the cross-sectional area of the material recess at the frictional contact region is smaller than at the axial side facing away from the frictional contact region, for a given volume for the material recess a reduction of the Reibkontaktbereichs be minimized by the material recess.

Particularly preferably, at least one material recess extends over the entire circumferential region, in particular substantially in the form of a circular ring, wherein the material recess is configured as a depression, which can be produced in particular by embossing. As a result, it is possible to prevent a edge of the material cutout, which extends in the radial direction, from scraping off and / or peeling off material from the opposite surface. An abrasive wear can be minimized. In addition, it can be avoided that during a relative rotation of the transfer flange to the support disk, lubricant accumulates at an edge pointing in the circumferential direction. Uneven lubrication can be avoided.

In particular, the transmission flange and / or the support disk have at least two material recesses offset from one another in the axial direction and / or in the radial direction. A uniform lubrication in the frictional contact region can be achieved by way of the various material recesses spaced apart from one another and in particular uniformly distributed.

Preferably, both the transmission flange and the support disk each have at least one material recess which opens toward the same friction contact region, the material recess of the transmission flange and the material recess of the support disk being arranged spaced from one another in the radial direction. Too much material weakening of the transfer flange or the support disk by a concentrated only in a component arrangement of material recesses can be avoided. In particular, the volume provided by the material recesses may be divided between the transfer flange and the support disk to receive a specific amount of lubricant. Preferably, a material recess may be provided only in the support disk for a specific radius region only in the transmission flange and for a radius region other than this, so that overlapping radius regions of opposing material recesses can be avoided.

Particularly preferably, the transmission flange, in particular for forming a slip clutch, axially frictionally clamped between a first support disk and a second support disk, wherein between the first support disk and the transmission flange, a first Reibkontaktbereich and between the second support disk and the transmission flange, a second Reibkontaktbereich is provided at least one material recess which is open towards the first friction contact region and also a material recess which is open toward the second friction contact region, wherein in particular the transmission flange has a material recess which is open towards the first friction contact region and open towards the second friction contact region as a passage opening. Both in the first friction contact region and in the second friction contact region, lubrication can be made possible by the at least one material recess. For this purpose, it is particularly possible to provide in the transmission flange as a material recess a through opening, which opens at the one axial end in the first Reibkontaktbereich and at the opposite end in the second Reibkontaktbereich. In addition, the lubricant provided in the material recess of the transfer flange can be retained by the support plates axially in the Reibkontaktbereichen.

In particular, a lubricant, in particular lubricating grease, is arranged in the material recess, wherein in particular the material recess is completely filled with lubricant. A subsequent supply of lubricant from another reservoir outside the torque limiter can be avoided. The structural design of the torque limiter can be kept low.

The invention further relates to a torsional vibration damper for torsional vibration damping in a drive train of a motor vehicle, in particular two-mass flywheel for torsional vibration damping between a drive shaft of an automotive engine and a transmission input shaft of a motor vehicle transmission, with a primary mass for introducing a torque, a limited relative to the primary mass rotatable secondary mass for discharging the torque the primary mass with the secondary mass torque transferable coupled, in particular designed as a bow spring, energy storage element and a torque limiter, which can be trained and further developed as described above, to limit the transmittable in a drive train of the motor vehicle torque, the secondary mass having a stopable on the energy storage element output flange wherein the output flange forms the transmission flange of the torque limiter. Due to the lubrication of the torque limiter, which can be achieved with the aid of the material cutout, it is possible to reduce the scattering of friction coefficients of the torque limiter, so that the avoidance of too high a high maximum transmittable torque Torque peaks in a drive train of a motor vehicle is possible.

The primary mass and the secondary mass arranged rotatably on the primary mass, which is configured in particular as a bow spring, can form a spring-mass system in the manner of a dual-mass flywheel, which in a certain frequency range initiates rotational irregularities in the rotational speed and in the torque of the mass introduced via the primary mass can dampen drive power generated by an automotive engine. Here, the mass moment of inertia of the primary mass and / or the secondary mass and the spring characteristic of the composite, for example, nested sheet springs energy storage element may be selected such that vibrations in the frequency range of the dominant engine orders of the motor vehicle engine can be damped. The primary mass can have a motor-side primary flange, which is directly or indirectly coupled to a drive shaft of an automobile engine and designed in the manner of a flywheel, to which a transmission-side cover can be connected, whereby a substantially annular receiving space for the energy storage element can be limited. For example, the primary mass can strike tangentially on the energy storage element via indentations projecting into the receiving space. In the receiving space, an output flange of the secondary mass protrude, which can strike tangentially at the opposite end of the energy storage element. With the output flange, an additional mass and / or a power transmission element for transmitting the torque to a downstream in the power flow unit, for example, by a riveted joint, be attached. The force transmission element is designed for example as a driver ring, which preferably forms a friction surface for a friction clutch and thereby simultaneously may be a counter-plate of the friction clutch, against which a pressure plate of the friction clutch can be axially displaced to between the drive plate designed as a counter-plate and the pressure plate a clutch disc to be frictionally pressed. The power transmission element can also be designed as an output hub, which can be coupled in a rotationally fixed manner to a shaft, in particular via a spline. The secondary mass, preferably the output flange and / or the force transmission element, may in particular be coupled indirectly via a clutch to a transmission input shaft of a motor vehicle transmission. The clutch may be configured, for example, as a friction clutch or hydrodynamic torque converter.

The invention further relates to a drive train for driving a motor vehicle having a drive shaft having a motor vehicle engine, a transmission input shaft having a motor vehicle transmission and provided in the torque flow between the drive shaft and the transmission input shaft torsional vibration damper, which may be as described above and further developed, and / or one Torque limiter provided in the torque flow between the drive shaft and the transmission input shaft, which may be formed and further developed as described above. The achievable with the help of the material recess lubrication of the torque limiter, a scattering of friction coefficients of the torque limiter can be reduced, so that at a high maximum torque transferable avoidance of excessive torque peaks in a drive train of a motor vehicle is possible.

• 1: eine schematische geschnittene Seitenansicht einer ersten Ausführungsform eines Drehmomentbegrenzers,
• 2: eine schematische geschnittene Seitenansicht einer zweiten Ausführungsform eines Drehmomentbegrenzers,
• 3: eine schematische geschnittene Seitenansicht einer dritten Ausführungsform eines Drehmomentbegrenzers,
• 4: eine schematische geschnittene Seitenansicht einer vierten Ausführungsform eines Drehmomentbegrenzers und
• 5: eine schematische geschnittene Seitenansicht einer fünften Ausführungsform eines Drehmomentbegrenzers.

The invention will now be described by way of example with reference to the accompanying drawings with reference to preferred embodiments, wherein the features shown below, both individually and in combination may represent an aspect of the invention. Show it:

• 1 FIG. 2 is a schematic sectional side view of a first embodiment of a torque limiter; FIG.
• 2 FIG. 2 is a schematic sectional side view of a second embodiment of a torque limiter. FIG.
• 3 FIG. 2 is a schematic sectional side view of a third embodiment of a torque limiter; FIG.
• 4 FIG. 2 is a schematic sectional side view of a fourth embodiment of a torque limiter and FIG
• 5 : A schematic sectional side view of a fifth embodiment of a torque limiter.

The in 1 illustrated torque limiter 10 For example, on the output side, it may be provided on a torsional vibration damper in order to prevent the transmission of excessive torque in a drive train of a motor vehicle, which could otherwise damage motor vehicle assemblies, for example a motor vehicle transmission, which are downstream in the torque flow. The torque limiter 10 has a transmission flange 12 on, which may be formed for example by an output flange of the secondary mass of a dual mass flywheel. The transmission flange 12 is between a larger first support disk 14 and a smaller second support disk 16 frictionally engaged up to axially clamped to a defined limit torque. The transmission flange 12 can be torque due to the frictional engagement with the support disks 14 . 16 transmitted, for example, with an output element designed as an output hub 18 , in particular via a riveted joint 20 , are connected. About the starting element 18 For example, the torque within the drive train can be forwarded to a disconnect clutch and / or a motor vehicle transmission. It is also possible that with the support disks 14 . 16 a sealing membrane 22 is attached.

If too much torque exceeds the limit torque from the transmission flange 12 in the torque limiter 10 is initiated, the static friction in one between the first support disk 14 and the transfer flange 12 formed first Reibkontaktbereich 24 and / or in one between the second support disk 16 and the transfer flange 12 formed second Reibkontaktbereich 26 be overcome, so that the transmission flange 12 with sliding friction on the support disks 14 . 16 slips. In this case, however, can still in the manner of a low-pass filter, a torque to the output element 18 be transferred from that during sliding friction between the transmission flange 12 and the support disks 14 . 16 still transmissible torque depends. So that the friction between the transmission flange 12 and the support disks 14 . 16 spreads over a much smaller area and the transmittable torque can be better predicted, the between the support discs 14 . 16 jammed transfer flange 12 in the friction contact areas 24 . 26 be lubricated.

In the in 1 illustrated embodiment is in the first support disk 14 a formed as a passage opening material recess 28 provided, which may be filled with a lubricant, in particular lubricating grease. The lubricant may be from the material recess 28 in the first frictional contact area 24 arrive and in the first Reibkontaktbereich 24 provide lubrication. Optionally, it may be provided that in the first Reibkontaktbereich 24 present lubricant on the transmission flange 12 radially inward past in the second Reibkontaktbereich 26 , for example through creep, can get. Preferably is also in the second support disk 16 a material recess 28 provided, which may be filled with a lubricant, in particular lubricating grease.

In the in 2 illustrated embodiment of the torque limiter 10 are compared to the in 1 illustrated embodiment of the torque limiter 10 the material recesses 28 in the support disks 14 . 16 not through a through-opening, but through only one friction contact area 24 . 26 designed open impression. The material recess 28 can also be radially inward to the transmission flange 12 be provided.

In the in 3 illustrated embodiment of the torque limiter 10 are compared to the in 1 illustrated embodiment of the torque limiter 10 the material recesses configured as a passage opening 28 not through the support disks 14 . 16 but through the transmission flange 12 educated. The material recesses 28 are offset from each other in the radial direction, wherein the radially inner material recess 28 both with the first friction contact area 24 as well as with the second Reibkontaktbereich 26 communicated. The radially outer material recess 28 communicates only with the first frictional contact area 24 , with the help of the radially larger first support disk 14 is trained.

In the in 4 illustrated embodiment of the torque limiter 10 are compared to the in 3 illustrated embodiment of the torque limiter 10 the material recesses 28 in the transmission flange 12 not through a through-opening, but through only one friction contact area 24 . 26 designed open impression.

In the in 5 illustrated embodiment of the torque limiter 10 are compared to the in 2 illustrated embodiment of the torque limiter 10 the embossed material recesses 28 in the support disks 14 . 16 in a common radius region of the respective associated friction contact region 24 . 26 arranged so that the lubricant only in the axial direction and no longer in the radial direction in the respective Reibkontaktbereich 24 . 26 can get.

In a further embodiment of the torque limiter 10 are various material recesses formed in the embodiments described above 28 provided mixed with each other. So it is possible, for example, that both in the transmission flange 12 as well as in the first support disk 14 and / or in the second support disk 16 a material recess 28 is provided.

LIST OF REFERENCE NUMBERS

10

torque

12

transmission flange

14

first support disk

16

second support disk

18

output element

20

rivet

22

sealing membrane

24

first friction contact area

26

second friction contact area

28

material cut

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102015218636 A1 [0002]

Claims (10)

Torque limiter for limiting a transmissible in a drive train of a motor vehicle torque, with a transmission flange (12) rotatable about a rotation axis for transmitting the torque, at least one support disk (14, 16) frictionally engaging with the transmission flange (12) for the frictional exchange of the torque with the transmission flange (12) up to a defined limit torque, wherein the transfer flange (12) and the support disk (14, 16) abut one another in a frictional contact region (24, 26) and at least one of the transfer flange (12) and / or the support disk (14, 16) formed to Reibkontaktbereich (24 , 26) open material recess (28) for receiving a lubricant. Torque limiter after Claim 1 characterized in that at least one material recess (28) extends over a limited peripheral region. Torque limiter after Claim 2 characterized in that the material recess (28) is formed as a passage opening. Torque limiter according to one of Claims 1 to 3 characterized in that at least one material recess (28) over the entire peripheral region, in particular substantially annular, extends, wherein the material recess (28) as, in particular producible by embossing, recess is configured. Torque limiter according to one of Claims 1 to 4 characterized in that the transmission flange (12) and / or the support disc (14, 16) at least two in the axial direction and / or in the radial direction mutually offset material recesses (28). Torque limiter according to one of Claims 1 to 5 characterized in that both the transmission flange (12) and the support disk (14, 16) each have at least one material recess (28) open towards the same friction contact region (24, 26), the material recess (28) of the transmission flange (12) and the material recess (28) of the support disc (14, 16) are arranged spaced from each other in the radial direction. Torque limiter according to one of Claims 1 to 6 characterized in that the transmission flange (12), in particular for forming a slip clutch, between a first support disc (14) and a second support disc (16) is axially frictionally clamped, wherein between the first support disc (14) and the transmission flange (12) a second friction contact region (26) is provided, wherein at least one material recess (28) opened towards the first friction contact region (24) and also a second friction contact region (FIG. 26) towards the open material recess (28) are provided, wherein in particular the transmission flange (12) to the first Reibkontaktbereich (24) and open towards the second Reibkontaktbereich (26) open as a passage opening configured material recess (28). Torque limiter according to one of Claims 1 to 7 characterized in that in the material recess (28) a lubricant, in particular lubricating grease, is arranged, wherein in particular the material recess (28) is completely filled with lubricant. Torsional vibration damper for torsional vibration damping in a drive train of a motor vehicle, in particular dual mass flywheel for torsional vibration damping between a drive shaft of an automotive engine and a transmission input shaft of a motor vehicle transmission, with a primary mass for introducing a torque, a limited relative to the primary mass rotatable secondary mass for discharging the torque, one the primary mass with the secondary mass torque transferable coupled, in particular designed as a bow spring, energy storage element and a torque limiter (10) according to one of Claims 1 to 8th for limiting the torque which can be transmitted in a drive train of the motor vehicle, the secondary mass having an output flange which can be hit by the energy storage element, the output flange forming the transmission flange (12) of the torque limiter (10). Drive train for driving a motor vehicle with a drive motor having a motor vehicle engine, a transmission input shaft having a motor vehicle transmission and provided in the torque flow between the drive shaft and the transmission input shaft torsional vibration damper Claim 9 and / or in the torque flow between the drive shaft and the transmission input shaft provided torque limiter (10) according to one of Claims 1 to 8th ,

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