WO2021069012A1

WO2021069012A1 - Damper device for a belt of a continuously variable transmission

Info

Publication number: WO2021069012A1
Application number: PCT/DE2020/100786
Authority: WO
Inventors: Nicolas Schehrer
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2019-10-08
Filing date: 2020-09-08
Publication date: 2021-04-15
Also published as: DE102020125633A1

Abstract

The invention relates to a damper device (1) for a belt (2) of a continuously variable transmission (3), said damper device having at least the following components: - at least one sliding surface (4, 5) for bearing against a strand (9) of a belt (2), said strand extending in the longitudinal direction (6); and - a reinforcement device (11) for reinforcing one of said sliding surfaces (4), said reinforcement device (11) comprising a reinforcement web (12) and reinforcement ribs (13, 14) extending in the transverse direction (7), the extension of the reinforcement web (12) in the longitudinal direction (6) being longer than its extension in the axial direction (8) and the extension of the reinforcement ribs (13, 14) in the axial direction (8) being longer than their extension in the longitudinal direction (6). The damper device (1) is particularly characterised in that the reinforcement web (12) and the reinforcement ribs (13, 14) are arranged in a meandering manner. The invention also relates to an injection moulding tool (21) and to an injection moulding method for producing such a damping device (1). The proposed damper device makes it possible to obtain a sliding surface which has high rigidity with a less complex injection moulding tool.

Description

Damper device for a wrapping means of a wrapping gear

The invention relates to a damper device for a belt means of a belt drive, having at least the following components:

- At least one sliding surface for bearing against a strand of a belt that extends in the longitudinal direction; and

a stiffening device for stiffening one of the sliding surfaces, the stiffening device comprising a stiffening web and stiffening ribs with extension in the transverse direction, the extension of the stiffening web in the longitudinal direction being longer than its extension in the axial direction and the extension of the stiffening ribs in the longitudinal direction being longer in the axial direction . The damper device is primarily characterized in that the stiffening web and the stiffening ribs are arranged in a meandering manner. The invention further relates to an injection molding tool and an injection molding method for producing such a damper device, a belt drive with such a damper device for a drive train, a drive train with such a belt drive, and a motor vehicle with such a drive train.

A belt transmission, also called a belt pulley transmission or CVT, for a drive train, for example a motor vehicle, comprises at least one input-side cone pulley pair arranged on a transmission input shaft and an output-side cone pulley pair arranged on a transmission output shaft as well as a torque transmission between the Conical pulley pairs provided belt. A conical disk pair comprises two conical disks, which are aligned with corresponding conical surfaces and are axially movable relative to each other. Usually one is (first) conical disk, also referred to as loose disk or movable disk, can be displaced along its shaft axis and a (second) conical disk, also referred to as fixed disk, is fixed in the direction of the shaft axis. Alternatively, both conical disks of a conical disk pair can be displaced. Such belt transmissions have long been known, for example from DE 100 17 005 A1.

When the belt drive is in operation, the belt is displaced in a radial direction between an inner position (small effective circle) and an outer position (large effective circle) due to the conical surfaces of the conical pulleys by means of a relative axial movement of the conical disks of a conical pulley pair. The looping means thus runs on a variable effective circle, that is to say with a variable running radius. As a result, a different speed ratio and torque ratio can be continuously adjusted from one pair of conical pulleys to the other pair of conical pulleys. The looping means forms two strands between the two conical pulley pairs, one of the strands forming a pulling strand and the other strand forming a pushing strand, or a load strand and an empty strand, depending on the configuration and the direction of rotation of the conical pulley pairs.

The direction perpendicular to the (respective) strand and pointing from the inside to the outside or vice versa is referred to as the transverse direction. The transverse direction of the first run is therefore parallel to the transverse direction of the second run only when the effective circles on the two conical disk pairs are of the same size. The direction perpendicular to the two strands and pointing from one conical disk to the other conical disk of a pair of conical disks is referred to as the axial direction. This is a direction parallel to the axes of rotation of the conical disk pairs. The third spatial direction in the (ideal) plane of the (respective) strand is referred to as the running direction or the opposite direction or the longitudinal direction. The direction of travel, the transverse direction and the axial direction thus span a Cartesian movement that is moved along with it (during operation) Coordinate system. The aim is that the running direction forms the ideally shortest connection between the adjacent active circles of the two conical pulley pairs, but in dynamic operation the alignment of the respective strand can deviate temporarily or permanently from this ideally shortest connection.

In the case of such belt drives, at least one damper device is provided in the free space between the cone pulley pairs. Such a damper device can be arranged on the tensile strand and / or on the thrust strand, preferably only on the respective load strand, of the belt and serves to guide and thus limit vibrations of the belt. Such a damper device is to be designed primarily with regard to an acoustically efficient traction means guide (looping means guide). The length of the adjacent (sliding) surface for guiding the belt and the rigidity of the damper device are decisive influencing factors. A damper device is designed, for example, as a sliding shoe or as a sliding guide with only one-sided sliding surface, mostly due to the installation space (transverse to the looping means), on the inside, that is to say arranged between the two strands. Alternatively, the damper device is designed as a slide rail with sliding surfaces on both sides, that is to say both on the outside, that is to say outside the formed looping circle, and on the inside sliding surface to the relevant strand of the looping means. A sliding surface is also known as a guide surface. In the case of a slide rail, the two transversely opposite, that is to say antagonistic or antagonistic, sliding surfaces acting on the strand to be damped are jointly referred to as a guide channel or sliding channel.

The damper device is mounted by means of a swivel means receptacle on a swivel means with a swivel axis, whereby a swiveling of the damper device about the swivel axis is possible. In some applications, the damper device can also be moved transversely, so that the damper device follows a (steeper oval) curve which deviates from a circular path around the pivot axis. The pivot axis thus forms the center of a (two-dimensional) polar coordinate system, with the (pure) angular movement corresponding to the change in the polar angle and the transverse movement corresponding to the change in the polar radius. This translational movement, which is superimposed on the pure angular movement, is disregarded in the following for the sake of clarity and is summarized under the term pivoting movement. The pivot axis is oriented transversely to the running direction of the belt, that is to say axially. This ensures that when adjusting the effective circles of the belt, the damper device can follow the resulting new (tangential) alignment of the belt in a guided manner.

Damping devices are mostly molded from a plastic, preferably by injection molding, for example from a low-friction polyamide, e.g. polyamide, preferably PA 46. For sufficient rigidity of the at least one sliding surface, a stiffening device is provided on the back of the (respective) sliding surface. In the prior art, the stiffening device is arranged such that a stiffening web is aligned with its longest extension in the longitudinal direction and the stiffening ribs are arranged transversely to one another and spaced apart from one another. The stiffening ribs and the stiffening web are connected to one another by means of T-crossing areas. To produce this arrangement with an injection molding tool with two mold halves which are axially guided against one another, a corresponding plurality of (axial) tool protrusions, possibly designed as separate tool inserts, is necessary from one side. When demolding the molding forming the damper device, axial holding forces (resulting from the surface friction between the mold half and the molding) are only exerted by the one-sided tool protrusions via the approximately axially aligned surfaces (the stiffening ribs). The molding thus remains in one half of the mold. A known solution for this is to use retaining pins on the other half of the mold to be used so that an approximately equal or greater holding force is generated from the other side.

Proceeding from this, the present invention is based on the object of at least partially overcoming the disadvantages known from the prior art. The features according to the invention emerge from the independent claims, for which advantageous configurations are shown in the dependent claims. The features of the claims can be combined in any technically meaningful manner, in which case the explanations from the following description and features from the figures, which include additional embodiments of the invention, can also be used.

- At least one sliding surface for bearing against a strand of a belt that extends in the longitudinal direction;

a pivot means receptacle for mounting the at least one sliding surface pivotable about an axial direction, the axial direction being aligned parallel to the at least one sliding surface and perpendicular to the longitudinal direction and a transverse direction being aligned perpendicular to the longitudinal direction and to the axial direction; and

a stiffening device for stiffening one of the sliding surfaces, the stiffening device comprising a stiffening web and stiffening ribs with extension in the transverse direction, the extension of the stiffening web in the longitudinal direction being longer than its extension in the axial direction and the extension of the stiffening ribs in the longitudinal direction being longer in the axial direction . The damper device is primarily characterized in that the stiffening web and the stiffening ribs are arranged in a meandering manner.

In the following, reference is made to the named spatial axes if the axial direction, the transverse direction or the longitudinal direction or the direction of travel and corresponding terms are used without explicitly indicating otherwise. Unless explicitly stated otherwise, ordinal numbers used in the preceding and following description are only used for clear distinction and do not reflect any order or ranking of the components identified. An ordinal number greater than one does not necessarily mean that another such component must be present.

According to the prior art, the damper device is set up for guiding or damping a belt or at least one strand of a belt of a belt drive. So that the sliding surfaces can be tracked in accordance with the (target) alignment of the strand to be guided, a pivot means receptacle is provided for a pivot means mounted on the damper device, for example in an embodiment described above. The belt means and the belt drive are conventionally designed, for example. The looping means is, for example, a link chain with rocker pressure pieces in a traction mechanism drive or a push link belt in a push link drive. The looping circle which surrounds the first and second pair of conical pulleys is formed by the looping means. The damper device has at least one sliding surface. if the damper device is designed as a sliding shoe or as a component part of a sliding shoe, a single sliding surface, for example a (transversely) inner, that is to say pivoting means-side, sliding surface is provided. In one embodiment of the damper device as a slide rail or as part of a Slide rail, an inner slide surface and an outer slide surface are provided, which form a slide channel for the strand to be guided. The at least one sliding surface is formed on a component with the greatest extent in the longitudinal direction as a surface with a normal in the transverse direction.

A stiffening device is provided on the back of the (respective) sliding surface. The stiffening device comprises a stiffening web and stiffening ribs, with the aid of which stiffening of the sliding surface is achieved, the stiffening against bending of the respective sliding surface along the longitudinal direction is achieved by aiming for the greatest possible extent in the transverse direction, comparable to a T-beam or an I-beam. The extent of the stiffening web is longer in the longitudinal direction than its extent in the axial direction and thus corresponds to the web of a T-beam or I-beam, the transverse extent being commonly referred to as the height. The height goes to the cube of the increase in rigidity against the aforementioned bending. The extension in the axial direction is as narrow as possible, commonly referred to as the width, because this simply goes into increasing the rigidity against bending. The length, that is to say here the extension in the longitudinal direction, of the stiffening web is based on the length of the respective sliding surface and is preferably just as long or only slightly shorter. The stiffening ribs are set up to stiffen the respective sliding surface against bending along the axial direction and / or set up for introducing forces onto the respective sliding surface into the (narrow) stiffening web.

It is now proposed here that the stiffening web and the stiffening ribs are arranged in a meandering manner. The meandering arrangement here relates to the plane spanned by the longitudinal direction and the axial direction. Meandering means, for example, spreading like a shape of a rectangular curve, trapezoidal curve, zigzag curve or similar two-dimensional shapes. It cannot be ruled out that the shape can change over the (transversal) height. For The shape is preferably constant over its height, so that it can be easily manufactured or has low tool costs and / or that it is easy to remove from the mold. It must be taken into account that in the meandering arrangement present here, no undercuts are integrated in the shape. Furthermore, a conical bevel (draft angle) of protrusions is preferably intended for easy removal from the mold, in that the meandering shape not only has no undercuts, but also has no exact axial alignment. In a preferred embodiment, the stiffening web has three web sections within the meandering shape. The web sections alternate with two stiffening ribs, whereby initially a first web section is formed, which adjoins a first stiffening rib, which in turn is followed by a second web section which is connected to a second stiffening rib (oriented opposite to the first stiffening rib), which follows in turn, a third web section adjoins. This results in a rectangular curve or a trapezoidal curve.

In order to create a meandering shape of the stiffening web with the stiffening ribs, at least one tool protrusion on one mold half and at least one tool protrusion on the other mold half, i.e. on each (axial) side, is necessary for mold halves of an injection molding tool that are axially guided to one another. Since a tool protrusion is necessary not only from one (axial) side, i.e. not only from one mold half, but from both sides, the (axial) holding force that occurs during demolding is distributed on both sides, preferably evenly, on the molding. This makes demolding easier. Retaining pins previously required for this can be omitted.

It should be pointed out that the stiffening web and the stiffening ribs in one embodiment only form parts of the stiffening device of one of the sliding surfaces. For example, other (preferably similar) stiffening elements are provided in further sections of the associated sliding surface. In one embodiment the meandering stiffening web and the stiffening ribs are arranged in the longitudinal direction (in each case) in front of and / or behind the pivoting means receptacle.

It is further proposed in an advantageous embodiment of the damper device that at least one of the stiffening ribs has a constant first wall thickness, and preferably the stiffening web has a constant second wall thickness.

At least one of the, preferably all, stiffening ribs of the stiffening device has at least one constant (first) wall thickness. It should be pointed out that the first wall thickness relates to the entire associated stiffening rib and that no further wall thickness is provided. Rather, the designation as the first wall thickness serves only to distinguish it from the (second) wall thickness of the stiffening web. The first wall thickness thus describes the thickness of the associated stiffening rib in at least one axial-longitudinal plane, preferably over the entire transverse extent of the associated stiffening rib. The constant (first) wall thickness is preferably designed such that the longest (approximately axial) extension is not aligned parallel to the axial direction, but extends at a helix angle. This constant (first) wall thickness reduces material accumulations, which is why the susceptibility to manufacturing errors is reduced and the necessary cooling period can be reduced; So if the conventional accumulation of material in the T-junction area determines the conventional cooling period, the (new) cooling period is hereby reduced. This results in a reduced cycle time for the production of the damper device by means of an original molding process, preferably an injection molding process. The stiffening web preferably also has a constant second wall thickness, which brings about the advantages mentioned above. For the second wall thickness, the definition for the first wall thickness applies analogously to the stiffening web. In an alternative embodiment, one or a plurality of the web sections has the constant second wall thickness. In a Embodiment, the web sections have mutually different, respectively constant (second) wall thicknesses. The second wall thickness is preferably constant and identical for the entire stiffening web. In a preferred embodiment, the first wall thickness, preferably all stiffening ribs, and the second wall thickness are identical in amount.

It is further proposed in an advantageous embodiment of the damper device that the damper device is a rail half of a slide rail, the damper device preferably being formed identically to another damper device of the slide rail.

In this embodiment, the damper device is part of the sliding rails, alternatively part of a sliding shoe. For many applications it is advantageous to design the slide rail in several parts, preferably in two parts, for example for easy assembly in a (for example conventional) belt drive. Then, for example, two separate rail halves are provided, which are connected to one another mechanically, for example positively and / or non-positively, for example as a so-called 1-click rail. In the case of a 1-click rail, a locking device is provided which secures a bayonet connection to prevent the two rail halves from coming loose from one another.

In a preferred embodiment, two damper devices (as rail halves) are provided which are each structurally identical with regard to the at least one sliding surface and / or the bearing surface of the pivoting means receptacle, particularly preferably identical overall. The two damper devices (as rail halves) preferably each have a, particularly preferably the same, portion of the respective sliding surface and / or the pivoting means receptacle. According to a further aspect, an injection molding tool for producing a damper device according to an embodiment according to the above description is proposed, the injection molding tool comprising a first mold half and a second mold half, the first mold half comprising a first axial tool protrusion and a third axial tool protrusion and the second mold half comprises a second axial tool protrusion, a meandering cavity for molding the stiffening web and the stiffening ribs being formed between the three axial tool protrusions.

In the injection molding process, an injection molding tool into which the liquefied extrudate is injected is used to manufacture the damper device. The injection molding tool is also referred to as a mold or a die and fulfills a fundamentally known task of primary shaping in an injection molding process. Depending on the number of items, the material and the multiple-part design are selected according to, for example, conventional standards, for example the injection molding tool is made of aluminum and all tool protrusions are formed in one piece with the respective mold half. The injection molding tool has (preferably exclusively) two mold halves, between which a cavity for forming the molding is formed, the damper device preferably being formed without post-processing. Sprue points are cut off during demolding, for example, or broken off after demolding in the event of a fall.

The mold halves each have tool protrusions. Between the mold halves, which are ready for injection (preferably purely axially), a meandering cavity is formed in the axially arranged tool protrusions, in which the stiffening web and the stiffening ribs are formed during injection. With the help of this arrangement, the necessary holding force is distributed on both sides of the mold halves. In one embodiment, the first mold half has two Tool protrusions and the second mold half have a tool protrusion so that, for example, the above-described rectangular curve or trapezoidal curve of the stiffening device is formed. In one embodiment, for example, more than three tool protrusions are provided.

The injection molding tool for producing the damper device preferably has no retaining pins in comparison to other damper devices, which in a conventional embodiment of such an injection molding tool are necessary for easy demolding of the stiffening web and the stiffening ribs or the entire molding. Due to a friction-related holding force of the molding with the tool protrusions in the injection molding tool arranged on both sides, which is now distributed on both sides of the injection molding tool, instead of only on one mold half as was previously the case, the use of retaining pins is easy, preferably when separating the mold halves from each other, Demoulding of the molding dispensable.

In one embodiment, in which a cooling line (for a particularly inexpensive embodiment of an injection molding tool) is not passed through the tool protrusions, the protrusion-side surface of the stiffening device is not particularly well cooled, but this is approximately even for both sides of the meandering area of the Stiffening device with the stiffening web and the stiffening ribs. In contrast to this, in a conventional embodiment with a T-shaped intersection area of the conventional stiffening web and the conventional stiffening ribs, cooling on the (flat) rear side of the stiffening web can simply bypassed even with an inexpensive embodiment of the cooling line, i.e. cooling on this side is good . On the front side of the stiffening web with the stiffening ribs, there is a cooling of the stiffening web and the stiffening ribs in an inexpensive embodiment of the cooling line Cannot be passed close by, so the cooling on this side is significantly worse. This leads to uneven and / or prolonged cooling.

It is further proposed in an advantageous embodiment of the injection molding tool that the mold halves, and preferably at least one of the tool protrusions, can be forcibly cooled.

The mold halves of the injection molding tool are designed in such a way that the molding is cooled more quickly by means of forced cooling. For example, cooling channels for a cooling liquid, for example water, are arranged in the wall of the injection molding tool, preferably as close as possible to the shaping surface. Forced cooling is preferably also or only provided in at least one of the tool protrusions or only in a region with a greater accumulation of material compared to other regions, for example by means of coolant cooling in corresponding channels. The cycle time can be reduced by means of this forced cooling.

According to a further aspect, an injection molding method for producing a damper device according to an embodiment according to the above description by means of an injection molding tool according to an embodiment according to the above description is proposed, comprising at least the following steps in the specified order: a. Keeping the injection molding tool ready and thus forming the meandering cavity for molding the stiffening web and the stiffening ribs; b. Injecting the plastic into the injection mold and forming a molding; c. after a cooling period, separating the two mold halves and removing the molded part formed, the molded part being retained in the area of the stiffening web and the stiffening ribs solely by means of the tool protrusions of the meandering cavity, the molding preferably forming the damper device without post-processing. A damper device as described above can be produced with the aid of the injection molding tool as described above with the injection molding method proposed here. In step a. (or sub-step a.1, compare below) such an injection molding tool kept ready. The meandering cavity in which in step b. the material of the stiffening web and the stiffening ribs is injected. In step b. a molding is thus formed. In a final step c. the two halves of the mold are separated after a cooling-off period. The molding is then removed from the injection molding tool or has already detached itself and is removed from a receiving receptacle, for example in an automated manner, for example by means of a conveyor belt. The molding can be easily removed from the mold because the stiffening web and the stiffening ribs are retained by friction only by means of the tool protrusions which form the meandering cavity, the holding forces of the mold halves being approximately balanced. In addition, the necessary cooling period, especially with a constant first and / or second wall thickness, is significantly reduced compared to a conventional injection molding process for manufacturing a conventional damper device, because no T-crossing areas are formed in which otherwise an accumulation of material is formed, especially as a result of the necessary Draft angle of the conventional stiffening ribs.

The molding preferably forms the damper device without the need for post-processing. For demolding, retaining pins are conventionally necessary in the injection molding tool so that the molding can be easily demolded from the mold halves. In the present embodiment there are no retaining pins, at least not for the meandering stiffening web and stiffening ribs of the stiffening device, because the tool protrusions arranged in both mold halves, i.e. on both sides, hold the molding back evenly on both sides. In one embodiment of the injection molding process, an (optional) sub-step aO is carried out before step a. (or sub-step a.1) carried out, in which a fiber material, for example a fleece, woven fabric and / or scrim, for example made of glass fiber, carbon fiber and / or a plastic fiber, is placed on at least one of the two mold halves, so that in step b. the plastic forms the so-called matrix and a fiber composite material is formed.

According to a further aspect, a belt transmission for a drive train is proposed, having at least the following components:

- A transmission input shaft with a pair of conical disks on the input side;

- A transmission output shaft with a pair of conical disks on the output side;

- A belt by means of which the conical pulley pairs are connected to one another in a torque-transmitting manner; and

- At least one damper device according to an embodiment according to the above description, wherein the at least one damper device for damping the belt is in contact with the at least one sliding surface on a strand of the belt.

With the belt transmission proposed here, a torque can be transmitted from a transmission input shaft to a transmission output shaft, and vice versa, in a step-up or step-down manner, the transmission being continuously adjustable at least in some areas. A belt drive is designed, for example, as shown at the beginning and the damper device or slide rail or slide shoe fulfills the task explained at the beginning. The components of the belt drive are usually enclosed and / or supported by a gear housing. For example, the pivoting means for the pivoting means receptacle is fastened to the transmission housing as a holding tube and / or is movably supported. The transmission input shaft and the transmission output shaft extend from the outside into the transmission housing and are preferably supported on the transmission housing by means of bearings. The cone pulley pairs are housed by means of the gear housing, and preferably the gear housing forms the abutment for the axial actuation of the movable conical disks. Furthermore, the gear housing preferably forms connections for attaching the belt drive and, for example, for the supply of hydraulic fluid. For this purpose, the transmission housing has a large number of boundary conditions and must fit into a given installation space. This interaction results in an inner wall that limits the shape and movement of the components. This represents the decisive limitation for the pivotable damper device, so that the shape must be designed on the basis of the transmission housing or its inner wall in order to achieve the best possible damping property.

The belt drive proposed here has at least one damper device which has good damping properties as a result of a desired rigidity of the at least one sliding surface with the stiffening device. At the same time, the damper device can easily be removed from the injection molding tool during an injection molding process, and the cycle time of the injection molding process is preferred compared to a conventional embodiment of a stiffening device without a meandering arrangement of stiffening web and stiffening ribs. The costs for a belt drive, in which a damper device is required, can thus be significantly reduced. The damper device proposed here can preferably be used for a conventional damper device without changing the installation space and / or the design of the at least one sliding surface.

According to a further aspect, a drive train is proposed, having at least one drive machine with a machine shaft, at least one consumer and a belt drive according to an embodiment according to the above description, wherein the at least one machine shaft for Torque transmission by means of the belt drive can be connected to the at least one consumer with a variable ratio.

The drive train is set up to generate a torque provided by one or a plurality of drive machines, for example an internal combustion engine and / or an electrical machine, and output via their respective machine shaft, for example the combustion shaft and / or the electrical machine shaft (rotor shaft) to be transmitted as required for use by a consumer, i.e. taking into account the required speed and the required torque. One use is, for example, an electrical generator to provide electrical energy or the transmission of torque to a propulsion wheel of a motor vehicle to propel it.

In order to transmit the torque in a targeted manner and / or by means of a gearbox with different ratios, the use of the belt transmission described above is particularly advantageous because a large ratio spread can be achieved in a small installation space and the at least one drive machine can be operated in a small optimal speed range.

Conversely, it is also possible to absorb inertial energy from the example of a drive wheel, which then forms a drive machine in the above definition, by means of the belt drive to an electrical generator for recuperation (the electrical storage of braking energy) with a correspondingly configured torque transmission train. In a preferred embodiment, a plurality of drive machines is provided which are connected in series or in parallel or can be operated decoupled from one another and whose torque can be made available as required by means of a belt drive according to the description above. One application example is a hybrid drive train, comprising an electric drive machine and an internal combustion engine. The drive train proposed here comprises a damper device in a belt drive, which has good damping properties as a result of a desired rigidity of the at least one sliding surface with the stiffening device. At the same time, the damper device can easily be removed from the injection molding tool during an injection molding process, and the cycle time of the injection molding process is preferred compared to a conventional embodiment of a stiffening device without a meandering arrangement of stiffening web and stiffening ribs. The costs for a belt drive, in which a damper device is required, and thus for a drive train, can thus be significantly reduced.

According to a further aspect, a motor vehicle is proposed, having at least one propulsion wheel, which can be driven by means of a drive train according to an embodiment according to the description above.

Most motor vehicles nowadays have a front-wheel drive and partially arrange the drive machine, for example an internal combustion engine and / or an electrical machine, in front of the driver's cab and transversely to the main direction of travel. The radial installation space is particularly small with such an arrangement and it is therefore particularly advantageous to use a small-sized belt transmission. The use of a belt drive in motorized two-wheelers is similar, for which, in comparison to previously known two-wheelers, increased performance is always required with the same installation space. With the hybridization of the drive trains, this problem is also exacerbated for rear axle arrangements, and also here both in the longitudinal arrangement and in the transverse arrangement of the drive machines.

In the motor vehicle proposed here with the drive train described above, a damper device in a belt drive has good damping properties as a result of a desired rigidity of the at least one sliding surface with the stiffening device. At the same time it is Damping device can be easily demolded from the injection molding tool in an injection molding process, and the cycle time of the injection molding process is preferred compared to a conventional embodiment of a stiffening device without a meandering arrangement of stiffening web and stiffening ribs. The costs for a belt drive, in which a damper device is required, and thus for a drive train, can thus be significantly reduced.

Passenger cars are assigned to a vehicle class according to, for example, size, price, weight and performance, whereby this definition is subject to constant change according to the needs of the market.In the US market, vehicles in the small car and micro car class according to European classification are assigned to the subcompact car class and on the British market, they correspond to the supermini class and the city car class. Examples of the small car class are a Volkswagen up! or a Renault Twingo. Examples of the small car class are an Alfa Romeo MiTo, Volkswagen Polo, Ford Ka + or Renault Clio. Well-known full hybrids in the small car class or compact class are the BMW i3, the Mercedes-Benz A 250 e or the Toyota Yaris Hybrid.

The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way restricted by the purely schematic drawings, it being noted that the drawings are not dimensionally accurate and are not suitable for defining size relationships. It is shown in

1: a damper device in a perspective view; 2: a damper device in a sectional view; 3: a schematic injection molding tool for producing the damper device;

4: a sequence for the sequence of an injection molding process by means of the injection molding tool;

5: a belt drive; and

6: a drive train in a motor vehicle with a belt transmission.

In Fig. 1, a damper device 1 or a molding 28 is shown in a perspective view. This damper device 1 is produced as a molding 28, for example by means of an injection molding tool 21 (see FIG. 3). In the embodiment shown, the damper device 1 has an inner sliding surface 4 and an outer sliding surface 5, both of which have their greatest extent in the longitudinal direction 6. The longitudinal direction 6 here is oriented approximately to the right in the image plane (inclined slightly into the image plane) and the axial direction 8 points upwards in the plane of the page. The transverse direction 7 is oriented perpendicular to the longitudinal direction 6 and to the axial direction 8 and thus points (inclined) into the plane of the sheet. The damper device 1 has a pivoting means receptacle 10, by means of which the sliding surfaces 4, 5 are mounted pivotably about the axial direction 8 (see FIG. 5).

The inner sliding surface 4 and the outer sliding surface 5 are connected to one another by means of a (transversely extending) connecting web 42. To stiffen the inner sliding surface 4, the damper device 1 has a stiffening device 11, which is arranged transversely offset inward (below, as shown, below) the inner sliding surface 4. Transversely offset outwards (above, as shown in the illustration), the outer sliding surface 5 also has a (further)

Stiffening device, which is not explained in more detail here. In one embodiment, the second stiffening device is designed in the same way. The position of the sectional view AA is also identified here, which leads approximately in the plane spanned by the axial direction 8 and the longitudinal direction 6 through the stiffening device 11 of the inner sliding surface 4. In FIG. 2, the damper device 1 according to FIG. 1 is shown in the sectional view AA. In this respect, reference is made to the previous description. In this illustration, the transverse direction 7 points (perpendicularly) into the plane of the sheet, so that the view is directed to the outer sliding surface 5. The stiffening device 11 of the embodiment shown has a stiffening web 12 and a first stiffening rib 13 and a second stiffening rib 14. The extension of the stiffening web 12 in the longitudinal direction 6 is longer than its extension in the axial direction 8. The extension of the first stiffening rib 13 and the second stiffening rib 13 in the axial direction 8 is longer than their extension in the longitudinal direction 6. The stiffening web 12 is divided into The (optional) embodiment shown in a first web section 15, a second web section 16 and a third web section 17, wherein in the embodiment shown (optional) the web sections 15, 16, 17 each have a longer extension in the longitudinal direction 6 than in the axial direction 8 exhibit. The stiffening ribs 13, 14 are arranged in such a way that their longest possible extension (along the helix angle 43 shown) is not aligned parallel to the axial direction 8. Rather, the stiffening ribs 13, 14 or their outer surfaces are aligned with a bevel angle 43 to the axial direction 8. While in conventional stiffening devices in which a straight and continuous stiffening web and at least one stiffening rib are arranged to form a T-shape with respect to one another, a large volume of solid material is formed in the T-intersection area. This is necessary for easy removal from the mold, for which an inclined wall of the (conventional) stiffening rib is required. Such a conventional stiffening rib tapers starting from the T-junction with the conventional stiffening web. In this case, the wall thickness of such a conventional stiffening rib is not constant, and it is greatest in the T-crossing area. Since the stiffening device 11 proposed here, the stiffening web 12 and the stiffening ribs are arranged in a meandering manner, no T-shaped intersection area is formed. Rather are a plurality of Connection kinks 44 formed without increased material accumulation. In addition, the stiffening ribs 13, 14 can be designed with a constant wall thickness 18, 19, as shown here on the first stiffening rib 13 (also applies to the second stiffening rib 14 with the opposite direction of inclination). An accumulation of material is avoided simply by avoiding a T-crossing and, moreover, with a constant wall thickness 18 of the stiffening ribs 13, 14. The cooling time for such a connection point between stiffening web 12 and stiffening ribs 13, 14 is reduced and the cycle time for the primary molding production of a damper device 1 or such a molding 28 can be reduced.

In this embodiment, the first stiffening rib 13 and the second stiffening rib 14 have a (first) constant wall thickness 18. Likewise, the stiffening web 12 preferably has a constant (second) wall thickness 19.

FIG. 3 schematically shows a section of an injection molding tool 21 for producing the damper device 1, the area 29 being shown in which the stiffening web 12 and the stiffening ribs 13, 14 can be formed in a meandering shape (see FIG. 2). With the aid of the injection molding tool 21, a molding 28, as shown, for example, in FIG. 2, can be produced, with the damper device 1 preferably being able to be produced without post-treatment. The injection molding tool 21 has a first mold half 22 and a second mold half 23. In this embodiment, the first mold half 22 has a first tool protrusion 24 and a third tool protrusion 25 and the second mold half 23 has a second tool protrusion 26, which is shown here separately from the remaining part of the respective mold half 22, 23 by means of single-dashed lines. By means of the first mold half 22 and the second mold half 23, a meandering cavity 27 is formed between the axially protruding tool protrusions 24, 26, 25, in which the stiffening web 12 and the stiffening ribs 13, 14 (see FIG. 1) can be molded. While in previously known stiffening devices 11 retaining pins in the damper device 1 are necessary because, due to the arrangement of the corresponding necessary tool protrusions from only one side, a retaining force is only applied on one side (axial) side is given. Therefore, the conventional molding does not fall out when the conventional mold halves are separated (with the conventional tool protrusions). In contrast to this, the present injection molding tool 21 exerts a holding force distributed on both (axial) sides due to the different directions of the tool protrusions 24, 26, 25, which is why the use of holding pins is no longer necessary. In a further embodiment, the tool protrusions 24, 26, 25 are formed in one piece with a mold half 22, 23. Alternatively, at least one of the tool protrusions 24, 26, 25 is formed by a separate insert element in the corresponding mold half 22, 23.

4 shows a flow diagram of the injection molding process. The components mentioned below and their reference symbols relate to FIGS. 1 to 3 without restricting the generality. In a step a. (here sub-step a.1) the injection molding tool 21 is kept ready and thus the meandering cavity 27 for molding the stiffening web 12 and the stiffening ribs is formed. In an (optional) preceding sub-step aO (sub-step of step a.), A fiber material, for example a glass fiber fleece, is placed on at least one of the two mold halves, so that a fiber composite material is formed. In a subsequent step b. a plastic is injected into the injection molding tool 21 and the molding 28 is formed, the two mold halves being held pressed against one another. In a final step c. the first mold half and the second mold half are separated from each other after a cooling period. The molding 28 produced can then be removed or it falls out when the two mold halves are separated. It should be noted that the molding 28 is retained (frictionally) in the area 29 of the stiffening web 12 and the stiffening ribs when the two mold halves are separated only by means of the tool protrusions of the meandering cavity 27. 5 schematically shows a damper device 1 in a belt drive 3, a first strand 9 (here for example the load strand) of a belt means 2 being guided and thus damped by means of the damper device 1. The belt means 2 connects a first pair of conical disks 32 with a second pair of conical disks in a torque-transmitting manner.At the first (here, for example, input-side) conical disk pair 32, which is connected to a transmission input shaft 31 for torque-transmitting rotation about an input-side axis of rotation 45, is located by appropriate spacing in the axial direction 8 (corresponds to the alignment of the axes of rotation 45, 46 and, as shown, shows into the plane of the sheet) an input-side active circle 47 on which the looping means 2 runs. On the second (here, for example, output-side) pair of conical pulleys 34, which is connected to a transmission output shaft 33 so as to be able to rotate about an output-side rotation axis 46 in a torque-transmitting manner, there is an output-side active circle 48 on which the belt 2 runs through appropriate spacing in the axial direction 8. The (changeable) ratio of the two active circuits 47, 48 results in the transmission ratio between the transmission input shaft 31 and the transmission output shaft 33.

With the circumferential direction 49 of the input-side conical disk pair 32 shown as an example and with torque input via the transmission input shaft 31, the damper device 1 forms an inlet side on the left and an outlet side on the right in the illustration. In an embodiment as a traction drive, the first strand 9 then forms the load strand as a traction strand and the second strand 50 the slack strand. If the belt 2 is designed as a push-link belt, under otherwise identical conditions, either the first strand 9 is guided as a slack strand by means of the damper device 1 or the first strand 9 is designed as a load strand and push strand and:

- The direction of rotation 49 and the direction of travel are reversed when torque is input via the first pair of conical disks 32; or - The transmission output shaft 33 and the transmission input shaft 31 are interchanged, so that the second pair of conical disks 34 forms the torque input.

In the following, for the sake of clarity (without limiting the generality), the belt drive 3 is described with a traction device as a belt device 2, for example designed as a link chain.

Between the two conical pulley pairs 32,34, the load strand 9 and the second strand 50 (here the slack strand) are shown in an ideal tangential alignment, so that the alignment of the longitudinal direction 6 for the damper device, which is parallel to the relevant tangent between the set effective circles 47, 48 1 sets in the load strand 9. The transverse direction 7 shown here is defined as a third spatial axis perpendicular to both the longitudinal direction 6 and the axial direction 8, the spanned coordinate system being understood as a coordinate system that is moved along with it (depending on the effective circle). Therefore, both the illustrated longitudinal direction 6 and the transversal direction 7 only apply to the illustrated damper device 1 and the load strand 9, specifically only to the illustrated set input-side active circle 47 and the corresponding output-side active circle 48.

The damper device 1 is (optionally here) designed as a slide rail 20 and lies with its first (here transversely inner) sliding surface 4 and its second (here transversely outer) sliding surface connected to it by means of the connecting web 42.

Sliding surface 5, which thus form a sliding channel, on the load strand 9 of the belt 2. So that the sliding surfaces 4, 5 can follow the variable tangential alignment, i.e. the longitudinal direction 6 when the active circles 47, 48 are changed, the pivoting means receptacle 10 is mounted on a pivoting means 51 with a pivoting axis 52, for example a conventional holding tube. As a result, the damper device 1 is mounted so as to be pivotable about the pivot axis 52. In the exemplary embodiment shown, the pivoting movement is made up of a superposition of a pure angular movement and a transverse movement a transversely aligned axis so that, in deviation from a movement along a circular path, there is a movement along an oval (steeper) curved path. In FIG. 6, a drive train 30 in a motor vehicle 41 is arranged with its engine axis 53 (optional) transverse to the longitudinal axis 54 (optional) in front of the driver's cab 55. In this case, the belt transmission 3 is connected on the input side to the rotor shaft 38 of the electric drive machine 36 and to the combustion shaft 37 of the internal combustion engine 35. From these drive machines 35, 36, or via their machine shafts 37, 38, a torque for the drive train 30 is delivered simultaneously or at different times. However, a torque can also be absorbed by at least one of the drive machines 35, 36, for example by means of the internal combustion engine 35 for engine braking and / or by means of the electric drive machine 36 for recuperation of braking energy. On the output side, the belt transmission 3 is connected to a purely schematically illustrated transmission, so that a left drive wheel 39 and a right drive wheel 40 (consumer) can be supplied with a torque from the drive machines 35, 36, with a (preferably continuously) variable ratio.

With the damper device proposed here, a high rigidity of a sliding surface can be achieved with a less complex injection molding tool at the same time.

Bezuqszeichenliste Damper device 29 Area of the meandering cavity Belt means 30 Drive train Belt drive 31 Transmission input shaft inner sliding surface 32 Input-side cone pulley pair outer sliding surface 33 Transmission output shaft longitudinal direction 34 Output-side cone pulley pair transverse direction 35 Internal combustion engine Axial direction 36 Electric drive gear 39 Stiffener internal combustion engine Axial direction 36 Electrical drive wheel Verififriebseinrichtung 37 Front drive shaft Motor vehicle second stiffening rib 42 connecting web first web section 43 helix angle second web section 44 connecting kink third web section 45 input-side rotation axis first wall thickness 46 output-side rotation axis second wall thickness 47 input-side active circle slide rail 48 output-side active circle injection molding tool 49 circumferential direction first mold half 50 empty tru m second mold half 51 pivoting means first tool protrusion 52 pivot axis second tool protrusion 53 motor axis third tool protrusion 54 longitudinal axis of meandering cavity 55 driver's cab molding

Claims

1. Damping device (1) for a belt (2) of a belt (3), having at least the following components: at least one sliding surface (4,5) for resting on a strand (9) of a belt (6) extending in the longitudinal direction (6) 2); a pivoting means receptacle (10) for mounting the at least one sliding surface (4, 5) pivotable about an axial direction (8), the axial direction (8) being aligned parallel to the at least one sliding surface (4, 5) and perpendicular to the longitudinal direction (6) and a transverse direction (7) is oriented perpendicular to the longitudinal direction (6) and to the axial direction (8); and a stiffening device (11) for stiffening one of the sliding surfaces (4), the stiffening device (11) comprising a stiffening web (12) and stiffening ribs (13, 14) extending in the transverse direction (7), the extent of the stiffening web (12) in the longitudinal direction (6) is longer than its extension in the axial direction (8) and the extension of the stiffening ribs (13, 14) in the axial direction (8) is longer than their extension in the longitudinal direction (6), characterized in that the stiffening web (12) and the stiffening ribs (13, 14) are arranged in a meandering manner.

2. Damper device (1) according to claim 1, wherein at least one of the stiffening ribs (13, 14) has a constant first wall thickness (18), and preferably the stiffening web (12) has a constant second wall thickness (19).

3. Damper device (1) according to claim 1 or 2, wherein the damper device (1) is a rail half of a slide rail (20), wherein preferably the damper device (1) is formed identically with a further damper device of the slide rail (20).

4. Injection molding tool (21) for producing a damper device (1) according to one of the preceding claims, wherein the injection molding tool (21) comprises a first mold half (22) and a second mold half (23), the first mold half (22) having a first axial one Tool protrusion (24) and a third axial tool protrusion (25) and the second mold half (23) includes a second axial tool protrusion (26), with a meandering cavity (27) for molding between the three axial tool protrusions (24,25,26) the stiffening web (12) and the stiffening ribs (13,14) is formed.

5. Injection molding tool (21) according to claim 4, wherein the mold halves (22, 23), and preferably at least one of the tool protrusions (24, 25, 26) can be forcibly cooled.

6. Injection molding method for producing a damper device (1) according to one of claims 1 to 3 by means of an injection molding tool (21) according to claim 4 or 5, comprising at least the following steps in the specified order: a. Holding the injection molding tool (21) ready and thus forming the meandering cavity (27) for molding the stiffening web (12) and the stiffening ribs (13, 14); b. Injecting the plastic into the injection molding tool (21) and forming a molding (28); c. after a cooling period, separating the two mold halves (22,23) and removing the molded article (28), the molded article (28) in the Area (29) of the stiffening web (12) and the stiffening ribs (13, 14) is retained solely by means of the tool protrusions (24, 25, 26) of the meandering cavity (27), the molding (28) preferably being the damping device (1) without post-processing. forms.

7. Belt drive (3) for a drive train (30), having at least the following components: a transmission input shaft (31) with a pair of conical pulleys (32) on the input side; a transmission output shaft (33) with a pair of conical disks (34) on the output side; a belt means (2) by means of which the pairs of conical pulleys (32, 34) are connected to one another in a torque-transmitting manner; and at least one damper device (1) according to one of claims 1 to 3, wherein the at least one damper device (1) for damping the belt means (2) with the at least one sliding surface (4,5) on a strand (9) of the belt means (2) ) is present.

8. Drive train (30), comprising at least one drive machine (35, 36) with a machine shaft (37, 38), at least one consumer (39, 40) and a belt drive (3) according to claim 7, wherein the at least one machine shaft (37 , 38) can be connected to the at least one consumer (39, 40) with a variable translation for torque transmission by means of the belt drive (3).

9. Motor vehicle (41), having at least one drive wheel (39, 40) which can be driven by means of a drive train (30) according to claim 8.