This application is related to Patent Application No. 1652377 filed Mar. 21, 2016 in France, the disclosure of which is incorporated herein by reference and to which priority is claimed.
The present invention relates to a pendulum damping device, in particular for a motor vehicle transmission system.
In such an application, the pendulum damping device may be incorporated into a torsional damping system of a clutch capable of selectively connecting the combustion engine to the gearbox in order to filter vibrations due to irregularities of the engine. One torsional damping system of this kind is, for example, a dual mass flywheel.
As a variant, in such an application the pendulum damping device may be incorporated into to a friction disc of the clutch or into a hydrodynamic torque converter or into a flywheel integral with the crankshaft or into a dual dry or wet clutch.
A pendulum damping device of this kind conventionally uses a support and one or more pendulum assemblies movable with respect to that support, the displacement of each pendulum assembly with respect to the support being guided by two bearing members interacting on the one hand with raceways integral with the support, and on the other hand with raceways integral with the pendulum assembly.
The support of the pendulum damping device must generally
In order to meet these two requirements it is known to utilize a support having two distinct portions, one of those portions of the support being specific to the physical attachment to the remainder of the transmission system, and the other of those portions being specific to guidance of the displacement of the pendulum bodies. Such a support is, however, costly to implement.
There is a need to take into account the two requirements mentioned above in a simple and inexpensive manner.
The object of the invention is to meet this need, which it does according to one of its aspects with the aid of a support for a pendulum damping device comprising:
the first portion and the second portion being rigidly connected to one another, and the first portion being obtained by cutting out the central zone of the second portion.
According to the invention, the first portion and the second portion of the support are implemented from only one part, for example a sheet of steel. As a consequence, it is not necessary to resort to two different original parts in order to implement the support. The scrap of the second part then forms the first portion of the support.
The separation of the original part into two portions then allows each portion of the support to be adapted to the requirement that that portion must meet, prior to rigid coupling between the two portions. For example, after being cut out the second portion is subjected to a hardening treatment in order to increase its strength. This treatment is, for example, a heat treatment allowing an addition of carbon in order to harden the second portion of the support. The addition of carbon is accomplished, for example, by carbonitriding or nitriding. This hardening treatment then does not affect the first portion of the support which has been separated from the second portion of the support, which is that much more advantageous given that a heat treatment of this kind may make it more difficult to attach the first portion of the support, by welding, to the remainder of the transmission system.
As a variant or a complement, a coating allowing vibrations of the support to be attenuated in the context of an impact by the mass against that support may be deposited onto the second portion of the support once the first portion has been cut out. The coating may be made of Deltaflon™ marketed by the Fluorotechnique® company. This coating may be applied onto the support by spraying, by electrolysis, or in a vapor phase. A coating of this kind utilizes PTFE.
The first raceway or raceways may already have been configured in the second portion of the support when the first portion is cut out.
As a variant, the first raceway or raceways may not yet have been configured in the second portion of the support when the first portion is cut out.
For purposes of the present application:
The first portion of the support may have on its radially external periphery an alternation of solid regions and open regions, the second portion of the support having on its radially internal periphery an alternation of solid regions and open regions. Moving along a given diameter, on the one hand an alternation of solid regions and open portions of the first portion of the support, and on the other hand an alternation of solid regions and open regions of the second portion of the support, may then be encountered.
Each solid and open region of the first portion of the support may respectively have a shape complementary to that of a respective open and solid region of the second portion of the support. This complementarity of shape may result from the first portion being cut out of the second portion of the support.
Each solid region of the first portion of the support has, for example, a petal shape in a plane orthogonal to the rotation axis.
The entirety of the solid regions of the first portion of the support here forms the radially external zone of the first portion of the support. Each solid region of the first portion of the support extends, for example, radially outward from a ring forming the radially internal zone of the first portion of the support. The support may be attached to the remainder of the transmission via this radially internal zone of the first portion of the support.
The first portion of the support may be axially offset with respect to the second portion of the support. The first portion of the support may extend for the most part radially inside the second portion of the support.
Each solid and open region of the first portion of the support may respectively be axially opposite all or part of a respective solid and open region of the second portion of the support. In other words, when the first portion and the second portion of the support are rigidly connected, for example once the treatments mentioned above have been performed, the first and the second portion are positioned in such a way that the solid regions of the first portion of the support are axially opposite solid regions of the second portion of the support.
The rigid connection between the first and the second portion of the support may utilize coupling members, each coupling member being received in a zone of a solid region of the first portion of the support, and in a zone of a solid region of the second portion of the support, which are axially opposite. These coupling members may be rivets extending axially. Each solid region of the first portion of the support may be connected rigidly to a solid region of the second portion of the support via at least one coupling member, in particular at least one rivet.
As a variant, the rigid connection between the first portion and the second portion of the support utilizes a force fit. The solid regions of the first portion of the support may have different dimensions with respect to one another. A solid region of the first portion of the support of a first type thus has, for example, a small radially internal dimension and a large radially external dimension, while a solid region of the first portion of the support of a second type has a large radially internal dimension and a small radially external dimension. The rigid connection is then effected by force-fitting
Force fitting is thus performed for each solid region of the first portion of the support of the first type at its radially external dimension, while force fitting is performed for each solid region of the first portion of the support of the second type at its radially internal dimension.
A further object of the invention according to another of its aspects is a pendulum damping device comprising:
The displacement of the pendulum assembly with respect to the support may be guided by two bearing members, in which case the damping device is referred to as “bifilar.”
Each bearing member interacts, for example, with at least one first raceway integral with the support and with at least one second raceway integral with the pendulum assembly. Each bearing member interacts, for example, with the raceway or raceways integral with the support, and with the raceway or raceways integral with the pendulum, only via its external surface.
Each bearing member is, for example, a roller circular in section in a plane perpendicular to the rotation axis of the support. This roller may comprise several successive cylindrical regions of different radii. The axial ends of the roller maybe devoid of a terminal annular rim. The roller is made, for example, of steel. The roller maybe hollow or solid.
In all of the above, the device comprises, for example, a number of pendulum assemblies between two and eight, in particular three, four, five, or six pendulum assemblies. All these pendulum assemblies may be successive to one another circumferentially. The device may thus comprise a plurality of planes, perpendicular to the rotation axis, in each of which all the pendulum assemblies are arranged.
In all of the above, the shape of the aforesaid first and second raceways may be such that each pendulum assembly is displaced with respect to the support only in translation around a notional axis parallel to the rotation axis of the support.
As a variant, the shape of the raceways may be such that each pendulum assembly is displaced with respect to the support
According to an exemplifying embodiment of the invention, the pendulum assembly may comprise a first pendulum mass arranged axially on a first side of the second portion of the support and a second pendulum mass arranged axially on a second side of the second portion of the support, the first and the second pendulum mass being integrated with one another via at least one connecting member.
According to this exemplifying embodiment of the invention the pendulum damping device may comprise a system for attenuating the noise produced upon an impact of the pendulum assembly against the support, this attenuation system being arranged axially on each side of the second portion of the support and axially clamping the latter.
The attenuation system may allow consideration of the undesirable noise and/or vibration of the support which occur in particular upon starting or shutdown of the combustion engine of the vehicle. This is because starting and shutdown of the combustion engine correspond to low engine speeds, which may result in a desynchronization of the pendulum assemblies with respect to the support, so that the pendulum assemblies may drop radially and strike against the support. Such an impact may then cause undesirable vibration and/or noise.
The noise attenuation system may comprise a first element arranged axially on a first side of the second portion of the support and a second element arranged axially on a second side of that second portion of the support.
This first and this second element may be separate parts integrated with the support, for example with the second portion of the support, in particular by fastening onto zones of the second portion of the support which are arranged radially beyond the solid regions of that second portion. Said fastening is accomplished, for example, by bolting, riveting, ultrasonic welding, thermal welding, etc.
Each element of the attenuation system may have on its radially internal periphery an alternation of solid regions and open regions. There exists, for example, an open region of the first element of said system which is axially opposite a solid region of the second element of said system while being axially opposite an open region of the first portion of the support and an open region of the second portion of the support. These two elements of the attenuation system may be fastened to one another via said two solid regions through the open axial space configured by the open regions of the support.
As a variant, there may exist zones of each element of the noise attenuation system which are axially opposite a solid region of the first portion of the support and opposite a solid region of the second portion of the support, and fastening of the noise attenuation system to the support may be accomplished via screws or rivets received in those zones and those solid regions. Other means may also be utilized for said fastening.
As yet another variant, the first and the second element of the noise attenuation system may be a single part overmolded onto the second portion of the support.
The second portion of the support may carry at least one axial interposition part arranged axially opposite the first pendulum mass or the second pendulum mass, that axial interposition part being in particular a coating deposited onto the support.
An interposition part of this kind may thus limit the axial displacement of the pendulum mass with respect to the support, thus avoiding axial impacts between said parts and therefore undesirable wear and noise, in particular when the support and/or the pendulum mass are made of metal.
When the interposition part is a coating, that coating is, for example, as mentioned previously.
As a variant, the axial interposition part may be a slider carried by the support. This slider may be made of plastic and may be hooked onto the support via one or more fastening tabs mounted in one or more support holes.
The interposition parts may be positioned on the support in such a way that there is always at least one interposition part at least a portion of which is axially interposed between a pendulum mass and the support, regardless of the relative positions of the support and of said mass.
According to this exemplifying embodiment, each pendulum assembly may comprise at least one abutment damping member capable of coming into contact simultaneously with the pendulum assembly and the support in relative positions of the pendulum assembly with respect to the support. Those relative positions are, for example:
Each abutment damping member may be dedicated to one connecting member of the pendulum assembly and carried by the latter. Each abutment damping member may have elastic properties allowing damping of the impacts associated with contact between the support and the pendulum assembly. That damping is then permitted by a compression of the abutment damping member, the latter being made, for example, of elastomer or of rubber.
The noise attenuation system may be different from an abutment damping member, in which case the noise attenuation system does not damp the abutment of the pendulum assembly against the support while simultaneously coming into contact with the pendulum assembly and the support.
According to a first preferred implementation, the bearing member interacts with only one first raceway and only one second raceway, and that second raceway is defined by the connecting member of the pendulum assembly. A region of the contour of that connecting member defines, for example, the second raceway. As a variant, a coating may be deposited onto that region of the contour of the connecting member in order to form the second raceway. A connecting member of this kind is, for example, force-fitted via each of its axial ends into an opening configured in one of the pendulum masses. As a variant, the connecting member may be welded or bolted or riveted via its axial ends onto each pendulum mass.
According to the first preferred implementation, the displacement of each pendulum assembly with respect to the support may be guided by at least two bearing members, in particular exactly two bearing members. Two connecting members, each interacting with one bearing member, may be provided.
Each bearing member may then be loaded only in compression between the first and second raceways mentioned above. Those first and second raceways which interact with the same bearing member may be at least in part radially opposite, i.e. there exist planes perpendicular to the rotation axis in which both of said raceways extend.
According to the first preferred implementation, each bearing member may be received in a window of the support which already receives a connecting member and does not receive any other bearing member. That window is defined, for example, by a continuous contour, a region of which defines the first raceway, integral with the support, which interacts with that bearing member.
According to a second preferred implementation, the bearing member interacts on the one hand with only one first raceway integral with the support, and on the other hand with two second raceways integral with the pendulum assembly. Each pendulum mass then has an opening, a portion of whose contour defines one of those second raceways.
According to this second preferred implementation, each connecting member encompasses, for example, several rivets, and that connecting member is received in a window of the support, while the bearing member is received in an opening of the support different from a window that receives a connecting member.
According to this second preferred implementation, two bearing members may guide the displacement of the pendulum assembly with respect to the support, and each bearing member interacts with a first raceway dedicated to that bearing member and with two second raceways dedicated to that bearing member.
According to this second preferred implementation, each bearing member may then comprise, axially successively:
According to this first exemplifying embodiment, there exists a single support that guides, via its second portion, the displacement of the pendulum bodies.
According to a second exemplifying embodiment, the displacement of each pendulum assembly may be guided by two supports, each being as mentioned above. Those two supports are then axially offset and integral. In this case the pendulum assembly may comprise only a single pendulum mass arranged axially between the two supports, or if applicable several pendulum masses integrated with one another and arranged axially between the two supports.
According to this second exemplifying embodiment of the invention, each support may carry a system for attenuating noise produced upon an impact of the pendulum assembly onto that support, that attenuation system being arranged axially on either side of the support and axially clamping the latter. As a variant, the noise attenuation system associated with each support is arranged axially only on that side of the support which faces toward the pendulum assembly.
A further object of the invention according to another of its aspects is a component for a transmission system of a motor vehicle, the component being in particular a dual mass flywheel, a hydrodynamic torque converter, a flywheel integral with the crankshaft, or a clutch friction disc, or a component of a hybrid transmission system, or a dual dry or wet clutch, or a single wet clutch, said component comprising a pendulum damping device as defined above.
The pendulum damping support may then be one among:
In the case in which the device is integrated into a flywheel integral with the crankshaft, the support may be integral with that flywheel.
The component is in particular a clutch friction disc. In such a case, the support may be connected to the hub of the friction disc. The first part of the support is, for example, fastened, in particular welded, onto that hub.
A further object of the invention according to another of its aspects is a method for producing a support for a pendulum damping device, comprising the following steps:
The method may comprise the step according to which the second part is subjected, after the cutting-out step and before the step of rigidly connecting the first portion, to a hardening treatment, for example carbonitriding or nitriding.
All or part of what has been mentioned with respect to the preceding aspect of the invention is also applicable to this other aspect.
A better understanding of the invention will be gained from reading the description below of a non-limiting exemplifying embodiment thereof, and from an examination of the attached drawings, in which:
That component 1 is in this case a clutch friction disk, only hub 3 being depicted here. That component 1 is associated, for example, with a combustion engine, in particular having two, three, or four cylinders.
In the example considered, pendulum damping device 2 comprises:
Three pendulum assemblies 5 are provided in the example considered, being distributed uniformly around axis X.
It is evident from
First portion 7 extends for the most part radially inside second portion 8, and that first portion 7 serves to physically attach pendulum damping device 2 to hub 3, in particular by welding.
Second portion 8 serves to guide the displacement of pendulum assemblies 5, as will be seen later.
First portion 7 is produced here by cutting out the central zone of second portion 8 of the support.
As is evident from
Similarly, second portion 8 of support 4 has on its radially internal periphery an alternation of solid regions 12 and open regions 13.
Because of the cutting that is performed, each solid region 10 of first portion 7 of the support has a shape complementary to the shape of each open region 13 of second portion 8 of support 4, and each solid region 12 of second portion 8 of support 2 has a shape complementary to the shape of each open region 11 of first portion 7 of support 4. It is thus evident that each solid region 10 is in the shape of a petal extending radially outward from a ring 14 fastened on hub 3.
As is evident from
Each solid region 10 and 12 has in this case a through hole, and the positioning of first portion 7 and of second portion 8 of support 4 allows those two holes to be axially aligned so that a screw or a rivet 15, forming a coupling member, is received through those two holes.
In the example considered, second portion 8 of support 4 has overall an annular shape having two opposite sides that in this case are planar faces.
As is evident from
In the example considered, connecting members 20, also called “spacers,” are offset angularly.
In
In the example shown in the Figures, each end of a connecting member 20 is welded onto a pendulum mass 6. In variants, each of those ends may be force-fitted into an opening configured in one of pendulum masses 6 of pendulum assembly 5 in order to integrate those two pendulum masses 6 with one another.
Each connecting member 20 extends in part in a window 22 configured in second portion 7 of support 4. In the example considered, window 22 defines an open space inside the support, that window being delimited by a continuous contour.
In the example considered, device 2 also comprises bearing members 21 that guide the displacement of pendulum assemblies 5 with respect to support 4. The bearing members are, for example, rollers.
In the example described, the movement of each pendulum assembly 5 with respect to support 4 is guided by two bearing members 21, each of them interacting, in the example shown in the Figures, with one of connecting members 20 of pendulum assembly 5.
Each bearing member interacts here with only one first raceway integral with support 4, and with only one second raceway integral with pendulum assembly 5, in order to guide the displacement of pendulum assembly 5.
In the example considered, each second raceway is formed by a radially external edge region of a connecting member 20.
Each first raceway is defined by a portion of the contour of a window 22.
Each first raceway is thus arranged radially opposite a second raceway, so that the same bearing surface of a bearing member 21 rolls alternatively on the first raceway and on the second raceway. The bearing surface of bearing member 21 is in this case a cylinder of constant radius.
As is evident from
As is also evident from
Attenuation system 30 comprises here a first element 31 arranged axially on a first side of second portion 8 of support 4, and a second element 32 arranged axially on a second side of said second portion 8.
This first element 31 and this second element 32 are in this case separate parts integrated with second portion 8 of support 4, that integration involving in particular a bolting operation or hot riveting of plastic rivets.
As is evident from
The invention is not limited to the example that has just been described.
Number | Date | Country | Kind |
---|---|---|---|
1652377 | Mar 2016 | FR | national |