CN116136250A - Slide rail with mechanism for belt transmission - Google Patents

Abstract

The invention relates to a sliding rail for a belt mechanism of a belt drive, comprising at least the following components: a sliding channel formed by an inner sliding surface and an outer sliding surface, wherein the sliding surfaces are oriented opposite one another and are each designed for bearing against a return section of the belt mechanism in a vibration-damped manner, the return section having a transverse height; and a bearing receptacle which is pivotably mounted on the holder of the transmission housing of the belt transmission about an axial direction for orienting the sliding surface as a function of the orientation of the return section to be damped, such that the sliding channel defines a longitudinal direction for the return section to be damped which is perpendicular to the transverse direction, wherein the sliding channel has a transverse channel height. The slide rail is mainly characterized in that the minimum channel height is smaller than the transverse height of the return section to be damped. Due to the small channel height of the sliding channel of the sliding rail, the damping effect for the acoustic-related vibrations of the guided return section can be increased.

Description

Slide rail with mechanism for belt transmission

Technical Field

The invention relates to a rail for a belt mechanism of a belt drive, a belt drive for a drive train having such a rail, a drive train having such a belt drive, and a motor vehicle having such a drive train.

Background

A belt drive for a motor vehicle, also called a conical disc belt drive or CVT (english: continuous variable transmission (continuously variable transmission)), comprises at least one first conical disc pair arranged on a first shaft and a second conical disc pair arranged on a second shaft, and a belt mechanism arranged for transmitting torque between the conical disc pairs. The conical disk pairs comprise two conical disks which are oriented toward one another by means of corresponding conical surfaces and can be moved axially relative to one another. Such belt drives generally comprise at least one first and second conical disk pair, which each have a first conical disk, also called a movable disk (Losscheibe) or a displacement disk (Wegscheibe), which is displaceable along the shaft axis, and a second conical disk, also called a stationary disk, which is fixed in the direction of the shaft axis, wherein the belt means provided for transmitting torque between the conical disk pairs run on a variable effective circle due to the conical surfaces, as a result of the relative axial movement between the movable disk and the stationary disk. In this way, different rotational speed and torque ratios can be set steplessly from one conical disk pair to the other conical disk pair.

When the belt drive is in operation, the belt mechanism is displaced in the radial direction between an inner position (small effective circle) and an outer position (large effective circle) by means of a relative axial movement of the conical disks, i.e. the conical disks of the conical disk pairs. The belt mechanism forms two return sections between two pairs of conical discs, wherein one of the return sections forms a tensioned return section and the other one forms a relaxed return section (depending on the configuration and direction of rotation of the pairs of conical discs), or one of the return sections forms a tensioned return section and the other one forms a relaxed return section.

Unlike the theoretical ideal case, the belt mechanism does not constantly leave the pair of conical discs in a tangential direction with respect to the corresponding pair of conical discs. Rather, the belt mechanism is driven or accelerated by the conical disk pair beyond the ideal operating point, so that vibrations are introduced into the return section. The vibrations negatively affect the acoustic properties of the belt drive and reduce efficiency.

In order to cope with this situation, in the case of such a belt drive, at least one slide rail which is pivotally supported on the holding device is provided in the free space between the conical disk pairs. Such a rail may be provided at the tension return and/or relaxation return of the belt mechanism and serve for guiding and thus limiting the vibration of the belt mechanism. However, friction generated between the slide rail and the return section negatively affects efficiency.

However, it is still suitable to acoustically improve the belt drive. Furthermore, the efficiency of the belt drive should be improved. This applies in particular to vehicles which are (at least sometimes) operated purely electrically or in which a belt drive is used in the E axle (i.e. solely by means of an electric drive). Since there the covering noise emissions generated by the internal combustion engine are omitted. However, the noise emissions of the belt drive, which are thus more pronounced, are generally perceived as unaccustomed and disturbing.

Disclosure of Invention

The present invention is based on the object of at least partially overcoming the disadvantages known from the prior art. Advantageous embodiments of the invention are explained below. The features of the invention can be combined in all technically significant ways and methods, wherein for this purpose the features from the following description and from the drawings can also be used, including additional embodiments of the invention.

The invention relates to a sliding rail for a belt mechanism of a belt drive, comprising at least the following components:

a sliding channel formed by an inner sliding surface and an outer sliding surface, wherein the sliding surfaces are oriented opposite one another and are each designed for bearing against a return section of the belt mechanism in a vibration-damped manner, said return section having a transverse height; and

A bearing receptacle which is pivotably mounted on a holder of the transmission housing of the belt transmission in an axial direction for orienting the sliding surface as a function of the orientation of the return section to be damped, such that the sliding channel defines a longitudinal direction for the return section to be damped which is perpendicular to the transverse direction,

wherein the sliding channel has a transverse channel height.

The slide rail is mainly characterized in that the minimum channel height is smaller than the transverse height of the return section to be damped.

In the following, reference is made to the mentioned longitudinal direction (which is equivalent to the direction of travel of the return section to be guided) when, unless explicitly indicated otherwise, a transverse direction and an axial direction perpendicular to the longitudinal direction, thus developing a cartesian coordinate system, and the corresponding terms, are used. If longitudinal, axial and transverse directions are referred to here, this means not only positive but also negative directions in the developed coordinate system. Furthermore, reference is made to a belt mechanism which, in the installed state, forms a belt circle surrounding the set effective circle of the two conical disk pairs of the belt drive, and with respect to the belt circle is referred to internally, i.e. is enclosed by the belt mechanism in the (imaginary) plane of the belt circle, and to externally and corresponding terms are used. The designations left return section and right return section relate to the sides of the longitudinal direction in parallel planes relative to the pivot axis, are arbitrarily selected (interchangeable) and are purely for simplicity of illustration. The use of numerical references in the foregoing and following description is for explicit distinction only and does not indicate the order or prioritization of the elements described, to the contrary, unless explicitly indicated. An ordinal number greater than one does not cause the necessity of the forced presence of additional such components.

According to the prior art, the slide rail is designed for damping belt means, for example endless chains or belts, belt drives having two conical disk pairs. For example, the belt means is embodied as a traction means or as a metal belt. This means that the slide rail is designed for one of the two return sections of the belt mechanism, for example for the traction return section forming the tensioning return section when configured as a traction mechanism drive. Alternatively, the slack return section or the two return sections are each guided by means of such a rail. If guidance of the return section is involved here, damping of the return section is thereby also meant, since the belt mechanism accelerates the conical disk pairs upstream in the direction of travel laterally outwards in a direction deviating from the ideal tangential direction of the set effective circles of the two conical disk pairs when transitioning into the return section. From there, shaft vibrations are caused which impair the efficiency and cause noise emissions. For example, vibration frequencies (stress-dependent) of the return section to be guided up to approximately 800hz [800 hz ] occur in belt drives and are acoustically dependent.

For guiding or damping, such a rail has two sliding surfaces which are oriented transversely opposite one another, wherein the inner sliding surface is designed from the transversely inner side and the outer sliding surface is designed from the transversely outer side for bearing against the return section to be guided during operation. In operation, the sliding surface is permanently or vibration-state-dependent against the return section to be guided. The sliding surface thereby forms a bearing surface extending in the longitudinal direction, which suppresses the transversely oriented amplitude of the shaft vibrations of the return section to be damped. The total length of the channel corresponds to the extension of the sliding channel in the longitudinal direction. The longitudinal direction runs parallel to the longitudinal direction of the return section guided in the sliding channel, along which the return section moves through the sliding channel, ignoring vibrations.

The slide rail comprises a bearing receptacle, wherein the bearing receptacle is positioned on the holding device. The holding device is surrounded by a transmission housing of the belt transmission. In one embodiment, the retaining means is formed integrally with the transmission housing. In a preferred embodiment, the holding device is formed separately from the gear housing and is connected to the gear housing fixedly or in an articulated manner.

The bearing receptacles of the sliding rail are designed to cooperate with the holding device in such a way that they can achieve a correspondingly oriented (passive) orientation of the sliding surface of the sliding rail relative to the return section to be damped. The sliding rail can therefore be pivoted about the axial direction by means of the bearing receptacle in conjunction with the holding device (following the return section to be damped). The sliding surface defines a longitudinal direction perpendicular to the transverse direction for the return section to be damped, and thus also defines the longitudinal direction. This ensures that, when the effective circle of the belt drive is adjusted, the slide rail can follow the new (tangential) orientation of the belt mechanism derived therefrom in a guided manner. Although the longitudinal direction is intended to form the ideal shortest connection between the applied effective circles of the two conical disk pairs, in dynamic operation the orientation of the respective return section may deviate briefly or permanently from the ideal shortest connection.

The lateral channel height is defined by the sliding channel. It should be noted that the channel height described here is defined in the cold state and outside the use of the transmission, in particular in the case of a non-accommodated return section. The channel height thus corresponds to the finished shape of the sliding channel, i.e. as a rail is then provided for the installation. In short, it is therefore referred to herein, unless explicitly stated to the contrary, a (cold) channel height which differs from the channel height which occurs in use and/or at operating temperature. However, the cold state does not necessarily correspond to a state at the lowest temperature according to the design of the slide rail, for example at-40 ℃ [ 40 ℃ below zero ]. By this is meant, for example, room temperature, preferably 20 ℃ to 25 ℃. The state at temperatures significantly below room temperature, for example from below 5 ℃ or from 0 ℃ is referred to herein as supercooled state. It should be noted that at the temperature at which the belt drive is operating, a gap may occur between the return section to be guided and at least one of the sliding surfaces, including the contact point.

The channel height is constant or variable over the longitudinal extension of the sliding channel. According to the present proposal, the minimum channel height is smaller than the height of the return section to be damped, i.e. the transverse extension of the return section to be guided. At least in the cold state, there is therefore an undersize between the sliding channel and the return section to be guided. In other words, in the cold state, a clamping exists between the sliding surface and the return section to be guided. It has been shown that the clamping is sufficiently small at least at the operating temperature, for example at 60 to 100 ℃, preferably at about 80 ℃ [80 ℃), so that the desired efficiency of the torque transmission can be achieved. At the same time, the achievable damping can be increased considerably by means of the described undersize (in the cold state).

In one embodiment the contact point is a part of a (technically) flat surface, in one embodiment the entire sliding surface of the slide rail. In one embodiment, the contact point is an extreme point of a spherical or wavy surface.

It should be pointed out that the return section to be guided is not necessarily in contact with the contact point of the sliding channel only, and may even give the following state: in this state, the return section to be guided is not in contact with at least one of the contact points, but is simultaneously in contact with the sliding surface, if necessary at a point outside the contact points.

Due to the reduced play or increased compression force between the sliding rail and the return section, the sliding rail dampens vibrations of the return section caused, for example, by the conical disk pairs when the belt mechanism is moved away. This reduces noise emissions or improves the acoustic effectiveness of the sled. Furthermore, despite the narrower abutment of the sliding rail, an increased efficiency occurs in a surprising manner even with an increased pressing force between the sliding surface and the return section.

Furthermore, in an advantageous embodiment of the slide rail, it is proposed that such a minimum channel height is defined by:

-between contact points laterally opposite each other; or alternatively

Between contact points offset from each other in the longitudinal direction by a longitudinal offset of at most 15%, preferably less than 10% of the longitudinal extension of the sliding channel.

In the first embodiment presented here, the minimum channel height corresponds to the actual narrowing of the sliding channel, since the contact points are arranged (technically) exactly opposite one another. It should be noted that in operation, the contact point, which cooperates with the return section to be guided, may be expanded to a contact surface (with at least one extension in the longitudinal direction) due to elastic, plastic and/or cutting deformations. It should furthermore be noted that the contact point is preferably defined in a section plane to which the axial direction is oriented normal. In one embodiment, the contact point is a contact line, for example a contact line parallel to the axial direction. In a further embodiment, the contact point is formed by a projection, wherein the projection is embodied in a channel-inward manner at least in one direction, preferably completely spherically. I.e. the contact point is then one or the extreme point of the protrusion.

In a further embodiment or in a further region of the sliding channel, a minimum channel height is defined between two contact points offset from one another. The contact points are spaced apart from one another so small that, with the considered order of the vibration of the return section to be guided, no evasive feasibility exists for the return section. In this region of the sliding channel, the (minimum) channel height that is effectively (vibration-damped) located against the return section is thus determined for the return section. For the considered order of the vibrations of the return section, preferably the first to fourth order, a spacing between the contact points of at most 15% of the longitudinal extension of the sliding channel is sufficient, said spacing defining the minimum channel height. The spacing is preferably equal to or less than 10% of the longitudinal extension of the sliding channel. In one embodiment, the contact points act at the same vibration antinode of the return segment. It should be noted herein that the orientation of the vibration antinode is variable due to contact with one or more contact points. Thus, reference is made herein to the following vibration antinodes: if the return section is free to vibrate (i.e. without damping by means of a rail), the vibration antinode will be constituted by the return section. Reference is made to the above definition regarding the shape and extension of the contact points.

In an advantageous embodiment of the slide rail, it is furthermore provided that the first minimum channel height is formed by means of a lateral projection of the outer slide surface in 20% to 30% from the longitudinal center of the slide channel and/or the second minimum channel height is formed by means of a lateral projection of the inner slide surface in 5% to 15% from the longitudinal center of the slide channel.

The at least one lateral projection extends into the channel interior in the lateral direction, thereby reducing the height of the sliding channel in the longitudinal direction beyond a certain section. Thus, the projection refers to a projection of the channel inwardly. The protruding portion has an extreme point. The extreme points are, for example, high points or high plateaus along the longitudinal direction and are referred to herein as contact points. Starting from the longitudinal center of the sliding channel, the extreme points are only set in the range of 20% to 30% of the total length of the channel in the longitudinal direction. Alternatively or additionally, the other extreme point of the same or of another projection is provided only in the range of 5% to 15% of the total length of the channel in the longitudinal direction. The centre of the extreme point is preferably arranged in the longitudinal direction at a distance of 25% and/or 15% of the total length of the channel with respect to the longitudinal centre of the sliding channel. Vibrations of the fourth order and of the third and/or second order, which are particularly acoustically relevant due to their frequency and volume, can thereby be damped particularly well.

The longitudinal center of the sliding channel is understood here to be a center plane which is oriented perpendicularly to the longitudinal direction and which is arranged equidistantly along the longitudinal direction relative to the two ends of the sliding rail. Alternatively or additionally, the longitudinal center is defined by the following plane: the pivot axis of the slide rail is also arranged in said plane.

Furthermore, in an advantageous embodiment of the slide rail, it is proposed that the minimum channel height is at least 0.05mm, preferably 0.1mm, particularly preferably 0.15mm, and at most 1.5mm, preferably 1.05mm, particularly preferably 1.0mm, smaller than the height of the return section.

In this case, an optimum should be found between the increased friction power, i.e. the potentially reduced efficiency of the belt drive, and the effective damping. In some cases and/or at some locations in the sliding channel, a narrowing of 50 μm [50 μm ] is already sufficiently acoustically effective. In other areas, a narrowing of 1.5mm [1.5 mm ] is necessary and/or not detrimental to efficiency. For example, certain areas are less actively abutted, but for this or exactly so, the vibrations involved are particularly disturbing. The reduced efficiency is then less disadvantageous. In yet other cases, one vibration is less high than the other vibrations. In this region, a narrower channel is then advantageous for good damping, while a smaller narrowing is sufficient for thicker vibration antinodes.

In an advantageous embodiment of the sliding rail, it is furthermore provided that the minimum channel height is formed by at least one lateral projection, wherein the projection preferably extends into the sliding channel by 0.3 mm.

By means of the lateral projections, a targeted partial contact can be produced, wherein the return section to be guided can vibrate more freely, preferably undisturbed, outside such projections, possibly by means of an expansion of the sliding channel (see maximum channel height below). In one embodiment, the minimum channel height is formed by means of a single projection, i.e. only present laterally on one side (for example at the outer sliding surface). Alternatively, the minimum channel height is formed by two laterally opposite projections.

It has been experimentally demonstrated that a protrusion with 0.3mm [0.3 mm ] gives particularly satisfactory results in terms of acoustic efficiency and causes small losses in terms of efficiency of torque transfer by means of the belt drive. In one embodiment (as described above), two laterally opposite (possibly slightly longitudinally offset) projections are formed such that a minimum channel height of 0.6mm [0.6 mm ] is achieved.

It should be noted that production tolerances should always be considered. For example, production tolerances of 0.3mm or more are common. It should then be determined by a person skilled in the art whether production tolerances should be reduced for the purpose and/or whether the desired orientation should be defined outside 0.3mm (e.g. in 0.4 mm) so that good results are achieved on average over a certain number of finished slide rails.

In an advantageous embodiment of the slide rail, it is furthermore provided that the maximum channel height is at least 0.05mm, preferably 0.1mm, particularly preferably 0.15mm, and at most 1.5mm, preferably 1.05mm, particularly preferably 1.0mm greater than the height of the return section, wherein the maximum channel height preferably exists outside the section of the slide channel with the transverse projections according to the embodiments described above.

In this case, an optimum should be found between the increased friction power, i.e. the potentially reduced efficiency of the belt drive, and the effective damping. In some cases and/or at some locations in the sliding channel, a 50 μm [50 μm ] expansion has been sufficient to increase efficiency by: where no friction power or reduced friction power is generated. In other areas, an expansion of 1.5mm [1.5 mm ] is necessary and/or not detrimental to acoustic efficiency. For example, a specific contact point is sufficient for effective damping of vibrations (of order). The contact in the region of the minimum channel height can then be dispensed with, so that the efficiency can be increased if necessary. In yet other cases (for example in the case of a specific order of vibration), it is advantageous to lie as large as possible against the return section to be guided. In this region, a narrower channel is then advantageous for good damping, while a smaller narrowing (i.e. a larger expansion) is however sufficient for a thicker vibration antinode.

It should be noted that it is not aimed at acoustic effectiveness to suppress any vibration antinode or to bring any vibration antinode into contact with at least one sliding surface. Rather, the expansion of the sliding channel is more targeted, since energy transmission with acoustic transmission and friction is then prevented there. Thereby also solid-borne sound transmission can be prevented.

In an advantageous embodiment of the sliding rail, it is furthermore provided that a first rail half and a second rail half are provided, wherein the rail halves are preferably formed identically, particularly preferably uniformly.

The slide rail is embodied such that it is formed by a first rail half and a second rail half. The rail halves of the rail are preferably each formed entirely in one piece, particularly preferably by means of injection molding, for example from polyamide [ PA ], preferably PA 46.

It is now proposed that the two rail halves are preferably identical rail halves. For example, such a rail half can be built axially on the return section to be damped from both sides during installation, or one rail half can already be installed and the other rail half can be built axially from the opposite side of the return section. In this case (since the rail halves are each identical in structure), the snap hooks are preferably guided into corresponding hook receptacles of the respective other rail half. The two rail halves are preferably designed in an overall identical manner, i.e. in a uniform manner, so that they can be produced by the same production method at all times during injection molding by means of a single injection mold. Thereby reducing production costs and without risk of confusion during installation. At least one of the sliding surfaces is formed by a partial surface of one of the rail halves.

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

-a transmission input shaft having a first pair of conical discs;

-a transmission output shaft having a second pair of conical discs;

-a belt mechanism by means of which the first pair of conical discs is connected in torque-transmitting manner with the second pair of conical discs; and

according to the slide rail according to the embodiment described above,

wherein the sliding rail for the damping belt mechanism rests with at least one sliding surface against the return section of the belt mechanism.

By means of the belt drive proposed here, torque can be transmitted from the transmission input shaft to the transmission output shaft in a step-up or step-down manner, and vice versa, wherein the transmission can be set at least in part steplessly. The belt drive is, for example, a so-called CVT with a traction mechanism or a metal belt. The belt mechanism is, for example, a multi-link chain. The belt means are pushed on the conical disk pairs from the radially inner side to the radially outer side in opposite directions, respectively, and vice versa, so that a variable effective circle appears on the respective conical disk pair. The ratio of the torques to be transmitted is derived from the ratio of the effective circles. The two effective circles are connected to each other by means of the upper return section and the lower return section of the belt mechanism, namely the tension return section and the relaxation return section, which are also referred to as the traction return section or the pushing return section.

Ideally, the return section of the belt mechanism forms a tangential orientation between the two effective circles. The tangential orientation is superimposed with the resulting axial vibrations, which are caused, for example, by a limited division of the belt mechanism and by the early departure from the effective circle due to the escape acceleration through the belt mechanism.

The sliding rail is designed to bear with its at least one sliding surface against a corresponding bearing surface of a return section to be damped, for example a tensioning return section, so that such shaft vibrations are suppressed or at least damped. In addition, for one application, a transverse guide is provided, i.e. a guide surface is provided on one or both sides in a plane parallel to the formed belt circle of the belt means. Then, a sliding channel is thereby formed in the case of a sliding rail having an outer sliding surface and an inner sliding surface. The return section is thus guided in a parallel plane with respect to the sliding surface, and the longitudinal direction of the return section lies in said parallel plane. For the best possible damping, the sliding surface is embodied as close as possible to the return section of the belt mechanism. Alternatively, the slide rail is axially fixed and the guided return section can be moved (axially) relative to the slide rail. The slide rail is embodied according to the embodiment described above, so that the damping effect of the acoustic-dependent vibrations for the guided return path can be increased by means of the small path height of the sliding path. At the same time, a high efficiency of the torque transmission can be achieved with good acoustic damping by means of the belt drive. In order to allow the sliding rail to follow the orientation of the return section, a pivot bearing is formed by the holding device, on which the sliding rail is supported with its bearing receptacle so that a pivoting movement according to the description above can be carried out. The slide rail is implemented according to one of the embodiments described above. The components of the belt drive are typically surrounded and/or supported by a drive housing. For example, a holding device (also referred to as a pivot bearing) for the bearing receptacle is fastened and/or movably mounted as a holding tube on the transmission housing. 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 conical disk pairs are surrounded by means of a transmission housing, and the transmission housing preferably forms a support for axially actuating the movable conical disk (movable disk). Furthermore, the transmission housing preferably forms a connection for fastening the belt transmission, for example for supplying hydraulic fluid and/or a liquid operating medium. For this purpose, the gear housing has a plurality of boundary conditions and must be adapted to a predetermined installation space. The shape and the inner wall of the movement of the limiting member result from said mutual cooperation.

According to another aspect, a powertrain is proposed, having: at least one drive machine, each of the at least one drive machine having a machine axis; at least one consumer; and a belt drive according to the embodiment described above, wherein the machine shaft can be connected with the aid of the belt drive with a variable transmission ratio, preferably a steplessly variable transmission ratio, to at least one consumer for transmitting torque.

The drive train is designed to transmit the torque provided by the drive machine, for example the internal combustion engine and/or the electric drive machine, and output via its machine shaft, for example the internal combustion engine shaft and/or the (electric) rotor shaft, for the purpose required, i.e. taking into account the required rotational speed and the required torque. For example, one use is a generator for providing electrical energy. In order to transfer torque specifically and/or by means of a gear change transmission having different gear ratios, the use of the belt drive described above is particularly advantageous, since a large transmission spread can be achieved in a small space and the drive machine can be operated in a small optimum rotational speed range. By contrast, by means of a correspondingly designed torque transmission system, for example, the inertial energy introduced by the propulsion wheel can also be absorbed by means of the belt drive to the generator for recuperation, i.e. electrical storage of the braking energy. In a preferred embodiment, a plurality of drive machines are furthermore provided, which can be operated in series or parallel connection or in a manner decoupled from one another and whose torques can be provided in a satisfactory manner by means of the belt drive according to the description above. An example of application is hybrid drive, which includes an electric drive machine and an internal combustion engine.

The drive train proposed here comprises a belt drive having one or two sliding rails, at least one of which is implemented according to the description above. The slide rail is embodied according to the embodiment described above, so that the damping effect of the acoustic-dependent vibrations for the guided return path can be increased by means of the small path height of the sliding path. At the same time, a high efficiency of the torque transmission can be achieved with good acoustic damping by means of the belt drive.

According to a further aspect, a motor vehicle is proposed, which has at least one propulsion wheel which can be driven by means of a powertrain according to the embodiment described above for propelling the motor vehicle.

Currently, most motor vehicles have a front wheel drive and drive machines, for example internal combustion engines and/or electric drive machines, are arranged partially in front of the driver's cabin and transversely to the main driving direction. The radial installation space is particularly small in this arrangement, so that it is particularly advantageous to use a belt drive of small construction dimensions. The use of belt drives in motor vehicles is of similar design, for which increased power is always required while maintaining the same installation space compared to previously known motor vehicles. The problem is exacerbated with the mixing of the powertrain.

The problem is exacerbated in small car class passenger cars classified according to europe. The plants used in passenger cars of the small vehicle class are not significantly reduced with respect to passenger cars of the larger vehicle class. The installation space available in a small vehicle is therefore significantly smaller. A similar problem arises in hybrid vehicles, in which a plurality of drives and clutches are provided in the drive train, so that the available installation space is reduced in comparison with non-hybrid motor vehicles.

The motor vehicle proposed here comprises a drive train with a belt drive having one or two sliding rails, at least one of which is implemented according to the above description. The slide rail is embodied according to the embodiment described above, so that the damping effect of the acoustic-dependent vibrations for the guided return path can be increased by means of the small path height of the sliding path. At the same time, a high efficiency of the torque transmission can be achieved with good acoustic damping by means of the belt drive.

Passenger cars are assigned vehicle grades based on, for example, size, price, weight, and power, wherein the definition varies continuously according to market demand. In the united states market, vehicles classified according to the class of small vehicles and micro vehicles are assigned to the class of ultra-small vehicles, while in the uk market, they correspond to the ultra-micro class or city vehicle class. General up-! Or reynolds two is an example of a class of micro-car. Alpha romidepa MiTo, mass Polo, ford ka+ or reynolds Clio are examples of small car grades. BMW 330e or Toyota Yaris Hybrid is a known Hybrid vehicle. For example, audi A6 50TFSI e or BMW X2 xTris 25e are known as mild hybrid vehicles.

Drawings

The invention described above is explained in detail below in the relevant technical background with reference to the associated figures, which show preferred embodiments. The invention is not in any way limited by the purely schematic drawings, wherein it is to be noted that the drawings are not dimensionally accurate and are not suitable for defining dimensional proportions. The drawings show:

fig. 1 shows a slide rail with a second minimum channel height in a schematic view;

fig. 2 shows the slide rail according to fig. 1 in a schematic view with a first minimum channel height;

fig. 3 shows a slide rail in a perspective view;

fig. 4 shows a slide rail in a belt drive in a schematic view; and

fig. 5 shows a drive train with a belt drive in a motor vehicle.

Detailed Description

Fig. 1 shows a slide rail 1 with a second minimum channel height 17 in a schematic view. The slide rail 1 is designed to guide the belt means 2 in a vibration-damped manner, wherein the belt means 2 is shown here in broken lines in some sections and has a transverse extension. Said lateral extension of the belt means 2 is the height 9 of the return section 7 to be guided. It should be noted that the components arranged on the left in the illustrated embodiment may also or only be arranged on the right according to the drawing. According to the illustration, the longitudinal direction 14 extends horizontally. The transverse direction 15 extends in the image plane perpendicularly to the longitudinal direction 14 (vertically according to the drawing), and the axial direction 13 likewise extends perpendicularly to the image plane perpendicularly to the longitudinal direction 14 and the transverse direction 15. The slide rail 1 extends along a longitudinal direction 14 and a longitudinal centre 21 is provided in the centre of the slide rail 1, said longitudinal centre being shown with a dash-dot line. The slide rail 1 comprises an inner slide surface 5 (shown here in the lower part) and an outer slide surface 6 (shown here in the upper part). The sliding surfaces 5, 6 are oriented counter to each other and are laterally spaced apart such that they form the sliding channel 4. In the exemplary embodiment, the lateral distance of the sliding channels 4 is limited to a maximum channel height 18, wherein the maximum channel height 18 is greater than the height 9 of the return section 7 to be guided, for example 0.15mm greater than the height of the return section to be guided.

The sliding channel 4 (or the inner sliding surface 5 and the outer sliding surface 6) is embodied such that, according to the illustration, two channel-inward projections 22 are provided in the sliding channel 4. It should be noted that the projection 22 is shown to be oversized for clarity. The inward projection 22 of the left-hand channel according to the illustration is arranged here on the outer slide surface 6 and is spaced apart from the longitudinal center 21 by a first longitudinal distance 37. The more longitudinally centered channel inward projection 22 according to the illustration is constituted by the inner slide surface 5 and is spaced apart from the longitudinal center 21 by a second longitudinal distance 38. For example, the first longitudinal distance 37 from the longitudinal center 21 is 20% to 30% of the longitudinal extension of the total length of the channels (from beginning to end) of the sliding channel 4, and/or the second longitudinal distance 38 from the longitudinal center 21 is 5% to 15% of the longitudinal extension of the total length of the channels.

In the embodiment, the two protrusions 22 are arranged relative to each other such that they have a longitudinal offset 20. The longitudinal offset 20 is for example less than 10% of the longitudinal extension of the total channel length of the sliding channel 4. The projections 22 are therefore not disposed directly opposite each other. Here, each projection 22 comprises a (preferably unique) contact point 19. The contact point 19 is here the contact point of the projection 22 with the belt means 2 during operation. In the embodiment described, the sliding channel 4 narrows to a second minimum channel height 17 between the two contact points 19 of the projection 22. Due to the predetermined narrowing of the sliding channel 4, an improved damping of the return section 7 excited to vibration during operation can be represented.

Fig. 2 shows a schematic view of the slide rail 1 according to fig. 1 with a first minimum channel height 16. Without excluding generality, the slide rail 1 is largely identical to the embodiment shown in fig. 1 purely for the sake of clarity, so that reference is made in this regard to the description there. It should be noted that the components arranged on the left in the illustrated embodiment may also or only be arranged on the right according to the drawing. Unlike the embodiment shown in fig. 1, the projections 22 shown here are arranged laterally directly opposite one another in the sliding channel 4. It should be noted that the projection 22 is shown to be oversized for clarity. In the exemplary embodiment, the contact point 19 defines a first minimum channel height 16, which is smaller than the height 9 of the return section 7 to be guided (see fig. 1), so that the sliding channel 4 is narrowed at a predetermined position. Due to the predetermined narrowing of the sliding channel 4, an improved damping of the return section 7 excited to vibration during operation can be represented.

Fig. 3 shows the slide rail 1 in a perspective view. According to the illustration, the longitudinal direction 14 extends from the lower left toward the upper right, the transverse direction 15 is oriented orthogonally to the longitudinal direction toward the upper left according to the illustration, and the axial direction 13 is in turn arranged orthogonally to both directions pointing towards the image plane. The slide rail 1 comprises (here two) rail halves 23, 24 which are identical in structure in a purely optional manner. The first rail half 23 and the second rail half 24 form a bearing receptacle 10, so that the slide rail 1 can be pivotally supported about the axial direction 13 (see fig. 4). The sliding channel 4 is delimited in the axial direction 13 by a first web 39 and a second web 40. For clarity, the channel inward projection 22 depicted in fig. 1 and 2 is not shown or visible in the perspective view.

Fig. 4 shows a rail 1 in a belt drive 3 (for example according to fig. 1 to 3) in a schematic view, wherein a return section 7 of the belt mechanism 2 is guided by means of the rail 1 (as shown in fig. 1 and described above) so as to be damped. The belt drive 3 is enclosed in a drive housing 12 which limits the available installation space. The belt mechanism 2 connects the first pair of conical discs 28 with the second pair of conical discs 29 in a torque transmitting manner. Here, for example, at a first conical disk pair 28, which is connected in a torque-transmitting manner to the transmission input shaft 26 in a rotatable manner about a (first) rotational axis 41 on the input side, there is a first (small) effective circle 43 on which the belt mechanism 2 runs, due to the corresponding spacing in the axial direction 13 (corresponding to the orientation of the rotational axes 41, 42). Here, for example, a second conical disk pair 29, which is rotatably connected to the transmission output shaft 27 in a torque-transmitting manner about a (second) rotational axis 42 on the output side, has a second (relatively large) effective circle 44, on which the belt means 2 runs, due to the corresponding spacing in the axial direction 13. The (variable) ratio of the two effective circles 43, 44 gives the gear ratio between the transmission input shaft 26 and the transmission output shaft 27.

The first return section 7 and the second return section 8 (guided here) are shown in a desired tangential orientation between the two conical disk pairs 28, 29, so that a parallel orientation of the longitudinal direction 14 (shown and belonging to the first return section 7) occurs. The transverse direction 15 shown here is defined perpendicular to the longitudinal direction 14 and perpendicular to the axial direction 13 as a third spatial axis, wherein this is understood as the coordinate system (associated with the effective circle) moving together. Thus, not only the illustrated longitudinal direction 14 but also the transverse direction 15 applies only to the illustrated slide rail 1 and the first return section 7, more precisely only in the case of the illustrated set effective circle 43 on the input side and the corresponding effective circle 44 on the output side. The slide rail 1 with its outer sliding surface 6 and its reactively oriented inner sliding surface 5 rests against the first return section 7 of the belt mechanism 2, so that a vibration-damping sliding channel 4 for the first return section 7 is formed. It should be noted that the possible channel inward protrusions 22 are also not shown here. In order to allow the sliding surfaces 5, 6 to follow a variable tangential orientation, i.e. the longitudinal direction 14, when the effective circles 43, 44 change, the bearing receptacle 10 is supported on the holding device 11 with the pivot axis 45. The slide rail 1 is thereby pivotally supported about a pivot axis 45. In the embodiment shown, the pivoting movement consists of a superposition of pure angular and transverse movements, so that, unlike the movement along a circular path, a movement along an elliptical (steeper) curved path occurs.

In the exemplary illustrated circumferential direction 46 and in the torque input via the transmission input shaft 26, the slide rail 1 in the illustration forms an inlet on the left and an outlet on the right. In the embodiment driven as a traction mechanism, the return section 7 to be guided then forms a tensioning return section 7 as a traction return section, and the further return section 8 forms a relaxation return section 8. In the embodiment of the belt mechanism 2 as a metal belt, under otherwise identical conditions, either the return section 7 to be guided is guided as a slack return section 8 by means of the slide rail 1, or the return section 7 to be guided is embodied as a tight return section 7, and:

upon input of torque via the first pair of conical discs 28, the wrapping direction 46 and the longitudinal direction 14 are reversed; or alternatively

The transmission output shaft 27 and the transmission input shaft 26 are exchanged such that the second conical disk pair 29 forms a torque input.

In fig. 5, a powertrain 25 in a motor vehicle 36 with a belt drive 3 is shown. The motor vehicle 36 has a longitudinal axis 47 and an engine axis 48, wherein the engine axis 48 is disposed in front of a cab 49. The drive train 25 comprises a first drive machine 30, which is preferably embodied as an internal combustion engine 30 and is then connected to the belt drive 3 on the input side in a torque-transmitting manner, for example via an internal combustion engine shaft 32. The second drive machine 31, which is preferably embodied as an electric drive machine 31, is then connected to the belt drive 3 in a torque-transmitting manner, for example, likewise via a rotor shaft 33. The torque for the drive train 25 is output by means of the drive machines 30, 31 or via their machine shafts 32, 33 simultaneously or at different times. However, it is also possible to absorb torque, for example by means of the internal combustion engine 30 for engine braking and/or by means of the electric drive machine 31 for recuperating braking energy. On the output side, the belt drive 3 is connected to a drive output, which is only schematically shown, so that the left propulsion wheel 34 and the right propulsion wheel 35 can be supplied with torque by the drive machines 30, 31 in a variable transmission ratio.

Due to the small channel height of the sliding channel of the sliding rail, the damping effect for the acoustic-related vibrations of the guided return section can be increased.

List of reference numerals

1. Sliding rail

2. Belt mechanism

3. Belt drive

4. Sliding channel

5. Inner sliding surface

6. Outer sliding surface

7. First return section

8. Second return section

9. Transverse height of return section

10. Bearing housing

11. Holding device

12. Transmission housing

13. Axial direction

14. Longitudinal direction

15. Transverse direction

16. First minimum channel height

17. Second minimum channel height

18. Maximum channel height

19. Contact point

20. Longitudinal offset

21. Longitudinal center

22. Protruding part

23. First rail half

24. Second track half

25. Power assembly

26. Transmission input shaft

27. Output shaft of transmission device

28. Input side conical disk pair

29. Conical disk pairs on the output side

30. Internal combustion engine

31. Electric driving machine

32. Internal combustion engine shaft

33. Rotor shaft

34. Left propulsion wheel

35. Right propulsion wheel

36. Motor vehicle

37. First longitudinal distance

38. Second longitudinal distance

39. First web plate

40. A second web

41. Axis of rotation on the input side

42. Axis of rotation on the output side

43. Effective circle of input side

44. Effective circle of output side

45. Pivot axis

46. Direction of wrapping

47. Longitudinal axis

48. Engine axis

49. Cab

Claims (10)

1. A slide rail (1) for a belt mechanism (2) of a belt drive (3), the slide rail having at least the following components:

-a sliding channel (4) formed by an inner sliding surface (5) and an outer sliding surface (6), wherein the sliding surfaces (5, 6) are oriented opposite each other and are each designed for bearing against a return section (7) of the belt mechanism (2) in a vibration-damped manner, said return section having a transverse height (9); and

a bearing receptacle (10) which is pivotably mounted on a holder (11) of a transmission housing (12) of the belt transmission (3) about an axial direction (13) for orienting the sliding surfaces (5, 6) as a function of the orientation of the return section (7) to be damped, such that the sliding channel (4) defines a longitudinal direction (14) perpendicular to a transverse direction (15) for the return section (7) to be damped,

wherein the sliding channel (4) has a transverse channel height (16, 17, 18),

it is characterized in that the method comprises the steps of,

the minimum channel height (16, 17) is smaller than the transverse height (9) of the return section (7) to be damped.

2. The slide rail (1) according to claim 1, wherein

Such minimum channel height (16, 17) is defined by:

-between contact points (19) laterally opposite each other; or alternatively

-between contact points (19) offset from each other in the longitudinal direction (14) by a longitudinal offset (20), wherein the longitudinal offset (20) is a maximum of 15% of the longitudinal extension of the sliding channel (4), preferably less than 10% of the longitudinal extension of the sliding channel.

3. The slide rail (1) according to claim 1 or claim 2, wherein

At 20% to 30% of the longitudinal center (21) of the sliding channel (4), a first minimum channel height (16) is formed by means of the lateral projections (22) of the outer sliding surface (6), and/or

At 5% to 15% from the longitudinal center (21) of the sliding channel (4), a second minimum channel height (17) is formed by means of a lateral projection (22) of the inner sliding surface (5).

4. The slide rail (1) according to any one of the preceding claims, wherein

The minimum channel height (16, 17) is at least 0.05mm, preferably 0.1mm, particularly preferably 0.15mm, smaller than the height (9) of the return section (7), and at most 1.5mm, preferably 1.05mm, particularly preferably 1.0mm smaller.

5. The slide rail (1) according to any one of the preceding claims, wherein

The minimum channel height (16, 17) is formed by at least one transverse projection (22), wherein the projection (22) preferably protrudes into the sliding channel (4) by 0.3 mm.

6. The slide rail (1) according to any one of the preceding claims, wherein

The maximum channel height (18) is at least 0.05mm, preferably 0.1mm, particularly preferably 0.15mm, and at most 1.5mm, preferably 1.05mm, particularly preferably 1.0mm, greater than the height (9) of the return section (7),

wherein the maximum channel height (18) is preferably present outside a section of the sliding channel (4) having a lateral projection (22) according to claim 3.

7. The slide rail (1) according to any one of the preceding claims, wherein

A first rail half (23) and a second rail half (24) are provided,

wherein the rail halves (23, 24) are preferably formed identically, particularly preferably uniformly.

8. A belt drive (3) for a powertrain (25), the belt drive having at least the following components:

-a transmission input shaft (26) having a first pair of conical discs (28);

-a transmission output shaft (27) having a second pair of conical discs (29);

-a belt mechanism (2) by means of which the first pair of conical discs (28) is connected in torque-transmitting manner with the second pair of conical discs (29); and

-a sliding rail (1) according to any of the preceding claims, wherein the sliding rail (1) for damping the belt means (2) rests with at least one of the sliding surfaces (5, 6) against a return section (7) of the belt means (2).

9. A powertrain (25) having: at least one drive machine (30, 31), each having a machine axis (32, 33); at least one consumer (34, 35); and a belt drive (3) according to claim 8,

wherein the machine shaft (32, 33) can be connected to the at least one consumer (34, 35) by means of the belt drive (3) with a variable transmission ratio, preferably a steplessly variable transmission ratio, for transmitting torque.

10. A motor vehicle (36) having at least one propulsion wheel (34, 35) which can be driven by means of a powertrain (25) according to claim 9 for propelling the motor vehicle (36).

Images