DE102017113092A1 - powertrain - Google Patents

Abstract

The invention relates to a drive train (1) of a drive (2) for the motorized adjustment of a closure element (3) of a motor vehicle, wherein a frictional engagement mechanism (6) is provided for providing a frictional force which is part of a braking mechanism (7) of the drive train (1) in that the frictional engagement mechanism (6) has at least two frictional engagement elements (8, 9, 10) which are frictionally engaged with one another and a pressure mechanism (11) for producing a pressure force (F) of the friction frictional elements (8, 9, 9, 10) towards one another wherein the frictional force results from the pressing force (F) and the static friction coefficient or coefficient of sliding friction between the frictional engagement elements (8, 9, 9, 10), and wherein the frictional engagement mechanism (6) is arranged in a brake housing (12). It is proposed that the brake housing (12) has at least a first brake housing section (12a) and a second brake housing section (12b) fixed thereto, which hold the friction locking mechanism (6) and which are configured and arranged relative to one another such that the influence of a temperature dependence of the Static friction coefficient and / or sliding friction coefficient between the frictional engagement elements (8, 9, 9, 10) is at least partially compensated for the resulting frictional force at least over a predetermined temperature range.

Description

The invention relates to a drive train of a drive for the motorized adjustment of a closure element of a motor vehicle according to the preamble of claim 1, a drive for the motorized adjustment of a closure element of a motor vehicle with such a drive train according to claim 12 and a closure element arrangement of a motor vehicle with such a drive according to claim 14 ,

The drive train in question of a drive is used in the context of the motorized adjustment of a closure element of a motor vehicle. Such closure elements may be, for example, doors, flaps, in particular tailgates, trunk lids, engine hoods, load compartment floors or the like of a motor vehicle. In that regard, the term "closure element" is to be understood in the present case.

The drive train in question serves to guide the power flow of the driving force generated by a drive motor of the drive. Accordingly, the drive train drive components such as shafts, gears, clutches, brakes o. The like. Have.

The well-known powertrain ( DE 10 2014 114 617 A1 ), from which the invention proceeds, is part of a spindle drive for the motorized adjustment of a tailgate of a motor vehicle. The drivetrain is associated with a frictional engagement mechanism designed as a brake mechanism, which on the one hand permits visually holding the tailgate in intermediate positions and on the other hand permits manual adjustment of the tailgate after overcoming the braking force of the braking mechanism.

The structural design of the known powertrain with brake mechanism and freewheel assembly basically ensures a relatively high reliability and in terms of manual adjustability a high degree of user comfort. A challenge in terms of reliability, however, is the fact that the frictional force provided by the friction mechanism is regularly temperature dependent. This temperature dependence is primarily due to the fact that the friction coefficient between the mutually frictionally engaged frictional engagement elements is also temperature-dependent. Since the resulting frictional force is proportional to the actual coefficient of friction, that is to say the coefficient of friction or the sliding friction coefficient depending on the type of frictional force, a temperature-dependent change of the respective frictional coefficient leads to a corresponding change in the resulting frictional force.

In order to counteract this effect at least partially, in the known drive train a pressing force of Reibschlusselemente each other to be generated spring element is provided which has a temperature-dependent spring characteristic and is used for temperature-dependent generation of the pressing force. The arrangement is made such that the temperature dependence of the pressing force at least partially compensates for the influence of the temperature dependence of the static friction coefficient and / or sliding friction coefficient on the resulting friction force. Nevertheless, it may happen that the frictional force at high outside temperatures is not sufficient to keep the tailgate o. The like., Or is so large at low outdoor temperatures that manual adjustment of the tailgate o. The like. At least significantly more difficult.

The invention is based on the problem, the known drive train to design and further develop that the reliability and ease of use is further improved.

The above problem is solved in a drive train according to the preamble of claim 1 by the features of the characterizing part of claim 1.

Essential is the fundamental consideration, the brake housing, in which the frictional engagement mechanism is arranged to design so that the temperature dependence of the static friction coefficient or sliding friction coefficient is opposed to a further temperature dependence, which at least partially compensates the influence of the former temperature dependence on the resulting frictional force. In the present case, the term "temperature" always describes the temperature prevailing on the brake housing and on the frictional engagement mechanism.

It has been recognized according to the proposal that for such a compensation, a temperature dependence of the brake housing, in particular at least a first brake housing portion and a second brake housing fixed thereto, if necessary. Also at least one particular to the first brake housing portion fixed third brake housing section is. "Fixed" means that the respective brake housing sections, each with one of its ends on a common support structure, in particular a connecting portion of the brake housing, are immovably mounted or extending from such a common support structure, so that the ends are fixed to each other. The brake housing sections can be in the Remaining but shift temperature dependent to each other. The temperature dependence of the brake housing or the entirety of the first brake housing section and the second brake housing section, if necessary. Third brake housing section, compensates for the influence of the temperature dependence of the static friction coefficient and / or the sliding friction coefficient between the frictional engagement elements on the resulting friction force at least partially over a predetermined temperature range. Thus, the components of the pressing mechanism, which serves to generate a pressing force of each mutually adjacent frictional engagement elements to each other, on the brake housing, in particular directly, stored, whereby a temperature-induced change in shape of the brake housing acts on the pressure mechanism. Accordingly, a reduction of the respective friction coefficient with a corresponding increase of the pressing force and an increase of the respective friction coefficient with a corresponding reduction of the pressing force is accompanied, so that nothing changes at best on the product of pressing force and friction coefficient.

In the embodiment according to claim 2, the thermal expansion coefficients, in particular coefficients of linear expansion relative to the direction of action of the pressing force of the material of the brake housing sections, d. H. the first brake housing section, the second brake housing section and optionally one or more further brake housing sections, and their lengths coordinated so that a temperature-dependent change in length of the first brake housing section by a temperature-dependent change in length of the second brake housing section and optionally one or more further brake housing sections at least over the predetermined temperature range at least partially compensated. With the "length" of a brake housing section whose dimension is meant parallel to the direction of action of the pressing force, which is hereinafter also referred to as axial or axial direction. The orthogonal direction is also referred to as radial direction or radial direction accordingly.

The requirements 3 and 4 define how the first brake housing section and the second brake housing section, as well as optionally one or more further sections of the brake housing, may be formed and arranged relative to each other.

Claim 5 defines a preferred embodiment of the pressing mechanism with a spring element for generating the pressing force. The term "spring element" includes in particular screws, springs, spiral springs, corrugated discs o. The like., But also gas spring elements o. The like. The spring element forms a, in particular also temperature-dependent, Andrückkrafterzeugungselement, alternatively or additionally, other Andrückkrafterzeugungselemente also be temperature dependent in particular can, as bimetallic elements, shape memory elements and / or Dehnstoffelemente, can be provided. All of these elements, which may be part of the pressing mechanism, may in turn also cause a temperature-dependent change in the pressing force and thus also contribute to the fact that the influence of a temperature dependence of the static friction coefficient and / or sliding friction coefficient is at least partially compensated for the resulting frictional force.

According to the embodiment according to claim 6, said influence of a temperature dependence of the static friction coefficient and / or sliding friction coefficient on the resulting friction force can be compensated for at least 70%, preferably at least 80%, more preferably substantially completely. The above applies at least for a predetermined temperature range, which is in particular between -40 ° C and + 80 ° C (claim 7). Particularly preferably, at least over the predetermined temperature range, a temperature dependence of the length difference between the length of the first brake housing section and the length of the second brake housing section is opposite to the temperature dependence of the static friction coefficient and / or sliding friction coefficient (claim 8).

The requirements 9 to 11 relate to preferred embodiments and applications of the friction locking mechanism of the proposed drive train.

According to a further teaching according to claim 12, which has independent significance, a drive for the motorized adjustment of a closure element of a motor vehicle is claimed which has a proposed drive train. Reference may be made to all versions of the proposed powertrain insofar as they are suitable for explaining the drive. A particularly slim design is shown in a construction according to claim 13, wherein the drive is designed as a spindle drive. In a further preferred embodiment according to claim 13, the geometric spindle axis of the spindle and the drive shaft of the drive motor associated with the drive are aligned.

According to a further teaching according to claim 14, which also has independent significance, a closure element arrangement of a motor vehicle with a closure element which is adjustably coupled to the body of the motor vehicle and claimed with at least one proposed drive for the motorized adjustment of the closure element. Again, reference may be made to all versions of the proposed powertrain and to the proposed drive.

• 1 in einer ganz schematischen Darstellung den Heckbereich eines Kraftfahrzeugs mit einer vorschlagsgemäßen Verschlusselementanordnung, die vorschlagsgemäße Antriebe mit jeweils einem vorschlagsgemäßen Antriebsstrang aufweist,
• 2 einen der Antriebe gemäß 1 im eingefahrenen Zustand in einem Längsschnitt,
• 3 in a) einen Bremsmechanismus einer ersten Ausführungsform des Antriebs gemäß 2 im Längsschnitt und in b) eine ganz schematische Darstellung des Funktionsprinzips anhand der ersten Ausführungsform und
• 4 in a) einen Bremsmechanismus einer zweiten Ausführungsform des Antriebs gemäß 2 im Längsschnitt und in b) eine ganz schematische Darstellung des Funktionsprinzips anhand der zweiten Ausführungsform.

In the following the invention will be explained in more detail with reference to a drawing illustrating only embodiments. In the drawing shows

• 1 in a very schematic representation of the rear area of a motor vehicle with a proposed closure element arrangement, the proposed drives each having a proposed drive train,
• 2 one of the drives according to 1 in the retracted state in a longitudinal section,
• 3 in a) a brake mechanism of a first embodiment of the drive according to 2 in longitudinal section and in b) a very schematic representation of the principle of operation with reference to the first embodiment and
• 4 in a) a braking mechanism according to a second embodiment of the drive according to 2 in longitudinal section and in b) a very schematic representation of the principle of operation with reference to the second embodiment.

The drive train shown in the drawing 1 is a drive 2 for the motorized adjustment of a closure element 3 , here a tailgate of a motor vehicle assigned. The powertrain 1 serves to guide the power flow of a drive motor 4 of the drive 2 generated driving force.

The application of designed as a tailgate closure element 3 is here in the foreground. However, the proposed solution is also applicable to all other types of fastener elements. The exemplary list in the introductory part of the description may be referred to.

The in 1 shown tailgate 3 are a total of two drives 2 assigned to the two side edges of a tailgate opening 5 and on the tailgate 3 attack yourself. The here each designed as a spindle drive drive 2 are ball cups at the end 2a . 2 B associated with the corresponding ball heads on the respective side edge of the tailgate opening 5 and on the tailgate 3 engage. The following is only of the in 1 visible drive 2 the speech. All designs apply to the in 1 invisible, underlying drive and for an arrangement with only a single drive 2 corresponding.

The powertrain 1 of the drive 2 is with a friction locking mechanism 6 equipped to provide a frictional force. In the in the 3 and 4 shown embodiments is the frictional engagement mechanism 6 Part of a brake mechanism 7 , The brake mechanism 7 serves the preferably continuous braking of the drive train 1 to the tailgate 3 to hold in intermediate positions. To additionally enable manual adjustment, the drive is 2 here and preferably not self-locking, so re-drivable, configured, so that after overcoming the braking force, a corresponding adjustment of the tailgate 3 is possible.

In the proposed drive train 1 has the frictional engagement mechanism 6 at least two or three, here and preferably exactly three frictionally engaging or engageable frictional engagement elements 8th . 9 . 10 and a pressure mechanism 11 for generating a pressing force F of the frictional engagement elements 8th . 9 respectively. 9 . 10 towards each other. In principle, it may be provided that at least one of the frictional engagement elements 8th . 9 . 10 a component of the pressure mechanism 11 forms, for example, the frictional engagement element here 10 , The friction elements 8th . 9 . 10 each have a friction surface, which are in frictional engagement with each other via the pressing force F or can be brought, wherein preferably at least a part of the frictional engagement elements 8th . 9 . 10 , here the friction element 9 is rotatable about a rotation axis X. The friction elements 8th and 10 are fixed against it here. Preferably, the pressing force F acts here axially relative to the axis of rotation X. However, embodiments are also conceivable in which the pressing force F acts radially relative to the axis of rotation X.

The of the frictional mechanism 6 Frictional force generated results from the pressing force F and from the relevant coefficient of friction between the Reibschlusselementen 8th and 9 respectively. 9 and 10 , In detail, the frictional force is proportional to the respective friction coefficient and the magnitude of the respective pressing force F. Whether here the static friction coefficient or the sliding friction coefficient between the Reibschlusselementen 8th and 9 respectively. 9 and 10 is relevant, results from the respective application. In the in the 3 and 4 both embodiments are both relevant coefficients of friction, since in both cases both static friction and sliding friction occur.

It is essential to first realize that with a certain Temperature dependence of the static friction coefficient and / or sliding friction coefficient between the frictional engagement elements 8th and 9 respectively. 9 and 10 must be expected. Since such a temperature dependence has an undesirable influence on the resulting frictional force, an appropriate compensation is provided according to the proposal.

Specifically, it is suggested that the brake housing 12 at least a first brake housing section 12a and a second brake housing section fixed thereto 12b , Here and preferably still a lid forming a third brake housing section 12c , as well as the first and second brake housing sections 12a . 12b interconnecting connecting section 12d having together the frictional engagement mechanism 6 hold and are configured and arranged to each other that the influence of a temperature dependence of the static friction coefficient and / or sliding friction coefficient between the adjacent frictional engagement elements 8th . 9 respectively. 9 . 10 is at least partially compensated for the resulting frictional force at least over a predetermined temperature range, here and preferably a temperature range between about -40 ° C and +80 ° C. This means that a temperature-induced increase of the respective friction coefficient with a corresponding reduction of the pressing force F of the pressing mechanism 11 goes along (and vice versa). In view of the fact that the temperature dependencies in question are seldom of a linear nature, the compensation will be able to take place only approximately approximately on a regular basis. Accordingly, it is preferred that the compensation for at least 70%, preferably at least 80% and in a particularly preferred and expensive to manufacture embodiment substantially completely.

The first brake housing section 12a and the second brake housing section 12b both extend in the direction of the pressure mechanism 11 , Starting from a common to the direction of action of the pressing force F orthogonal plane E, along here to the Andrückmechanismus 11 facing side of the connection section 12d runs, wherein the brake housing sections 12a and 12b are at least not cohesively or positively connected with each other in the radial direction and between the brake housing sections 12a and 12b in particular, an annular gap is provided. In particular, the first brake housing section extend 12a and the second brake housing section 12b at least in sections, parallel to each other.

Here and preferably, the thermal expansion coefficient, in particular coefficient of linear expansion, of the material and the length L _{1 of} the first brake housing section 12a and the thermal expansion coefficient, in particular coefficient of linear expansion, of the material and the length L _{2 of} the second brake housing section 12b chosen or matched to one another such that a temperature-dependent change in length ΔL _{1 of} the first brake housing section 12a by a temperature-dependent change in length ΔL _{2 of} the second brake housing section 12b is compensated at least partially over the predetermined temperature range, in particular is completely compensated or, as in the 3 and 4 is even overcompensated.

Overcompensation is particularly useful when the Andrückmechanismus 11 for generating the pressing force F a Andrückkrafterzeugungselement, here and preferably a spring element 13 , Which has such a temperature-dependent Andrückcharakteristik, in particular spring characteristic or spring constant, that with increasing temperature, the generated pressing force F decreases at the same length (and vice versa). The overcompensation of the change in length ΔL _{1 of} the first brake housing section 12a by the change in length ΔL _{2 of} the second brake housing section 12b then at least partially allows a compensation of the temperature-dependent deterioration of the pressing characteristic or decrease of the spring constant.

The "length" here denotes the dimension parallel to the direction of action of the pressing force F. Accordingly, when a length or length change or a coefficient of linear expansion is mentioned, this or this always related to a direction parallel to the direction of action of the pressing force F, which hereinafter also referred to as axial direction. A direction orthogonal to it we call accordingly as a radial direction.

When in the embodiments in the 3 and 4 shown arrangement of the individual components of the friction locking mechanism 6 , which is part of a brake mechanism 7 is that on a drive component 18 of the powertrain 1 acts, in particular the arrangement of the brake housing sections shown 12 . 12b . 12c , it is preferred if the thermal expansion coefficient of the material of the first brake housing section 12a smaller than that of the material of the second brake housing section 12b , So has the brake housing 12 Here is a extending in the axial direction, substantially cylindrical brake housing section 12a on, which is opposite to this surrounding drive housing section 14 is rotationally fixed. Radially within the first brake housing section 12a is the second brake housing section 12b from a different material arranged, which is also substantially cylindrical. In the axial direction of the second brake housing section 12b spaced is a third brake housing section 12c provided in the form of a lid which is annular here. Here and preferably, the first brake housing section 12b and the second brake housing section 12c each rotationally fixed to the first brake housing section 12a arranged. The third brake housing section 12c is here inside the first brake housing section 12a arranged and, for example via a threaded connection, relative to the first brake housing section 12a adjustable in the axial direction. Radially within the first brake housing section 12a is also a about an axis of rotation X relative to the brake housing 12 rotatable connecting element 15 arranged, which is a first portion of a drive component 18 of the powertrain 1 , here a drive shaft section 16 , with a second section of the powertrain drive component 1 , here another drive shaft section 17 , connects. The drive component 18 That's from the two sections here 16 and 17 is formed, here and preferably a drive shaft 18 ,

The larger part of the connection element 15 is here and preferably also in the interior of the second brake housing section 12b and / or the third brake housing section 12c arranged, wherein a radially encircling, smaller part of the connecting element 15 axially between the second brake housing section 12b and the third brake housing section 12c is arranged. This forms a frictional engagement element 9 of the connection element 15 , The connection element 15 is here shown in one piece, but is preferably formed of several parts, wherein the inner, larger part and the radially encircling, smaller part are each separate components.

The friction element 9 acts with a here and preferably disc-shaped frictional engagement element 8th together, between the frictional engagement element 9 and the second brake housing section 12b is arranged. In principle, the frictional engagement element 8th Also part of the second brake housing section 12b be. In the axially opposite direction, the frictional engagement element acts 9 with a here and preferably also disk-shaped frictional engagement element 10 together, via the Andrückkrafterzeugungselement in the form of the spring element 13 , which in turn is on the lid-shaped third brake housing section 12c axially supported, is subjected to a compressive force. About the axially adjustable third brake housing section 12c Here, the pressing force F or spring force can be adjusted individually.

This in 4 illustrated embodiment has substantially the same structure as that in 3 illustrated embodiment, with the difference that the spring force generating element, here the spring element 13 , the pressure mechanism 11 between the second brake housing section 12b and the radially protruding, the frictional engagement element 9 forming portion of the connecting element 15 is arranged, in which case and preferably between the Andrückkrafterzeugungselement or spring element 13 and the frictional engagement element 9 the already described upper frictional engagement element 8th is arranged.

In principle, it is also conceivable that both between the second brake housing section 12b and the frictional engagement element 9 as well as between the third brake housing section 12c and the frictional engagement element 9 in each case a Andrückkrafterzeugungselement, in particular spring element 13 , is arranged. Alternatively, both between the second brake housing section 12b and the frictional engagement element 9 as well as between the third brake housing section 12c and the frictional engagement element 9 to a separate Andrückkrafterzeugungselement or spring element 13 be waived. Also on the here and preferably disc-shaped frictional engagement element 8th and / or frictional engagement element 10 can be omitted, as well as the second brake housing section 12b and / or third brake housing section 12c even the friction element 8th respectively. 10 can form.

In both embodiments, both according to 3 as well as according to 4 , expand at a temperature increase of the first brake housing section 12a and the second brake housing section 12b , starting from the plane E or the connecting section 12d , parallel to each other and in the axial direction, ie parallel to the direction of action of the pressing force F, from. The second brake housing section 12b is here and preferably shorter than the first brake housing section 12a and disposed in the interior thereof, wherein the first brake housing section 12a here with a stop 19 for the second brake housing section 12b forming connecting section 12d of the brake housing 12 is connected, starting from which the first and second brake housing section 12a . 12b in the direction of the pressure mechanism 11 extend and expand at a temperature increase. Alternatively it can also be provided that the first brake housing section 12a and the second brake housing section 12b , in particular by a connecting section 12d of the brake housing 12 , are integrally connected and form, for example, a 2K component (two-component component), wherein the first brake housing section 12a and the second brake housing section 12b from the connecting section 12d or from a common plane E in the direction of the pressure mechanism 11 extend and at a temperature increase in extend this direction. In a temperature reduction, it is accordingly in each case so that the respective brake housing section 12a respectively. 12b accordingly contracts in the axial direction. The first brake housing section 12a and the connecting section 12d of the brake housing 12 are here and preferably integrally connected (made of one piece), but can also be cohesively, non-positively and / or positively connected to each other. The same applies to the connection between the second brake housing section 12b and the connection section 12d of the brake housing 12 ,

By the construction described above, a rotation of the connecting element 15 and according to the drive component or drive shaft 18 braked by the friction elements 8th and 9 respectively. 9 and 10 each generate a frictional engagement, which generates a braking torque or a braking force.

As already explained above, the pressure mechanism 11 as Andrückkrafterzeugungselement at least one spring element 13 have, wherein the spring element 13 here and preferably in a Federbauraum 20 is arranged, here and preferably in the axial direction of the third brake housing section 12c to the lower frictional engagement element 10 ( 3 ) or of the second brake housing section 12b up to the upper frictional engagement element 8th ( 4 ). This causes a temperature-dependent change in length .DELTA.L _{1 of} the first brake housing section 12a and a temperature-dependent change in length ΔL _{2 of} the second brake housing section 12b over the predetermined temperature range together a corresponding change in length of the spring space 20 whereby a change in the spring constant, in particular a reduction in the spring constant at a temperature increase or an increase in the spring constant at a temperature reduction, at least partially can be compensated.

Here and preferably, it is such that at least over the predetermined temperature range, a temperature dependence of the length difference L ₁ -L ₂ between the length L _{1 of} the first brake housing section 12a and the length L _{2 of} the second brake housing section 12b opposite to the temperature dependence of the static friction coefficient and / or the coefficient of sliding friction between the frictional engagement elements 8th . 9 respectively. 9 . 10 , This means, as explained above, that an increase in the relevant friction coefficient is accompanied by a reduction of the pressing force F (and vice versa). In a particularly preferred embodiment, the amount of the slope of the relevant friction coefficient over the temperature is identical to the amount of the slope of the pressing force F on the temperature, each over the predetermined temperature range.

The proposed according to provided temperature-dependent change in length of the two brake housing sections 12a and 12b and the corresponding change in length of the spring space 20 , in each case based on the axial direction or direction of action of the pressing force F, is the example of a temperature increase for the embodiment according to 3a schematically in 3b and for the embodiment according to 4a schematically in 4b shown. On the left is in each case the state at a lower temperature, in particular ambient temperature, and on the right in each case the state at a higher temperature. It can be seen that the length L _{1 of} the first brake housing section 12a and the length L _{2 of} the second brake housing section 12b at a temperature increase respectively increased (to L ₁ 'and L ₂ '), wherein the length L _{1 of} the first brake housing section 12a but considered in absolute terms less enlarged than the length L _{2 of} the second brake housing section 12b , In other words, the temperature-dependent change in length ΔL _{1 of} the first brake housing section 12a smaller than the temperature-dependent change in length ΔL _{2 of} the second brake housing section 12b , Accordingly, the length difference L ₁ -L ₂ between the length L _{1 of} the first brake housing section decreases 12a and the length L _{2 of} the second brake housing section 12b with increasing temperature (to L ₁ '-L ₂ '). This also reduces the length L _{3 of} the spring space 20 with increasing temperature (to L ₃ '), which in turn has an increase of the pressing force F result, by which a temperature-induced decrease of the coefficient of static friction and / or sliding friction coefficient between the frictional engagement elements 8th . 9 respectively. 9 . 10 and / or the spring constant can be at least partially compensated.

According to another doctrine, which has independent significance, the above drive becomes 2 claimed as such. The proposal according to claim 2 is used according to the motorized adjustment of a closure element 3 a motor vehicle, wherein a drive train 1 is provided, which is designed according to the former teaching. On all versions of the proposed powertrain 1 may be referred.

In a particularly preferred embodiment shown in FIG. 2, the drive is the drive 2 around a spindle drive. The drive 2 has a drive motor 4 and a drive motor 4 downstream spindle spindle nut transmission 21 with a spindle 22 and an associated spindle nut 23 for generating linear drive movements. In 2 implied is the fact that in the illustrated and so far preferred embodiment of the friction locking mechanism 6 of the drive 2 between the drive motor 4 and the spindle-spindle nut transmission 23 is switched.

According to another doctrine, which also has independent significance, an in 1 shown closure element assembly of a motor vehicle claimed as such. The proposed closure element arrangement has a locking element which is adjustably coupled to the body of the motor vehicle 3 and at least one proposed drive 2 for the motorized adjustment of the closure element 3 on. On all versions of the proposed drive 2 may be referred.

In a particularly preferred embodiment, it is such that the drive 2 not self-locking, so re-drivable, designed and that as a braking mechanism 7 configured frictional engagement mechanism 6 the closure element 3 when the drive is switched off 2 in intermediate positions, preferably in any intermediate position holds. In a particularly preferred embodiment, the closure element 3 when the drive is switched off 2 manually against the braking effect of the brake mechanism 7 adjustable. Of particular importance in this context is the fact that the overall arrangement is such that the brake mechanism 7 the closure element 3 when the drive is switched off 2 holds in intermediate positions, in particular with regard to the weight of the closure element 3 and possibly on the closure element 3 acting spring arrangements. Such spring arrangements may be, for example, gas spring arrangements or the like.

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102014114617 A1 [0004]

Claims (15)

Drive train of a drive (2) for the motorized adjustment of a closure element (3) of a motor vehicle, wherein a frictional engagement mechanism (6) is provided for providing a friction force, which is part of a braking mechanism (7) of the drive train (1), wherein the frictional engagement mechanism (6) at least two mutually frictionally engaged or brought frictional engagement elements (8, 9, 10) and a pressing mechanism (11) for generating a pressing force (F) of the frictional engagement elements (8, 9, 9, 10) toward each other, wherein the frictional force the friction force (F) and the static friction coefficients between the frictional engagement elements (8, 9, 9, 10), and wherein the frictional engagement mechanism (6) is arranged in a brake housing (12), characterized in that the brake housing (12) at least a first brake housing portion (12a) and a second brake housing section fixed thereto (12b), which the Rei holding mechanism (6) and which are configured and arranged to each other, that the influence of a temperature dependence of the static friction coefficient and / or sliding friction coefficient between the frictional engagement elements (8, 9; 9, 10) is at least partially compensated for the resulting frictional force at least over a predetermined temperature range. Drive train after Claim 1 characterized in that the coefficient of thermal expansion of the material of the first brake housing section (12a) and the length (L ₁ ) of the first brake housing section (12a) and the thermal expansion coefficient of the material of the second brake housing section (12b) and the length (L ₂ ) of the second brake housing section (12) 12b) are selected such that a temperature-dependent change in length (ΔL ₁ ) of the first brake housing section (12a) parallel to the direction of action of the pressing force (F) by a temperature-dependent change in length (ΔL ₂ ) of the second brake housing section (12b) parallel to the direction of action of the pressing force (F) is at least partially compensated, in particular completely compensated or overcompensated, preferably that the coefficient of thermal expansion of the material of the first brake housing section (12a) is smaller than the thermal expansion coefficient of the material of the two th brake housing portion (12b) is. Drive train after Claim 1 or 2 , characterized in that the first brake housing portion (12a) and the second brake housing portion (12b) in dependence on a temperature change parallel to each other and / or parallel to the direction of action of the pressing force (F), preferably that the second brake housing portion (12b) at least at Ambient temperature and in particular in the predetermined temperature range has a smaller length (L ₂ ) parallel to the direction of action of the pressing force (F) than the first brake housing portion (12a). Drive train according to one of the preceding claims, characterized in that the first brake housing portion (12a) with a stop (19) for the second brake housing portion (12b) forming the connecting portion (12d) of the brake housing (12), in particular in one piece, is connected, of the the first brake housing section (12a) and the second brake housing section (12b) extend in the direction of the pressure mechanism (11) and expand in response to a temperature change, or in that the first brake housing section (12a) and the second brake housing section (12b) via a connecting section (12d) are integrally connected and extend from the connecting portion (12d) in the direction of the pressing mechanism (11) and expand in response to a change in temperature. Drive train according to one of the preceding claims, characterized in that the pressure mechanism (11) at least one spring element (11) for generating the pressing force (F), which is arranged in a spring space (20), preferably, that a temperature-dependent change in length (.DELTA.L ₁ ) of the first brake housing section (12a) parallel to the direction of action of the pressing force (F) and a temperature-dependent change in length (ΔL ₂ ) of the second brake housing section (12b) parallel to the direction of action of the pressing force (F) together at least over the predetermined temperature range a change in length of the spring space (20) effect parallel to the direction of action of the pressing force (F). Drive train according to one of the preceding claims, characterized in that the influence of a temperature dependence of the static friction coefficient and / or sliding friction coefficient between the frictional engagement elements (8, 9, 9, 10) on the resulting friction force over the predetermined temperature range to at least 70%, preferably at least 80 %, more preferably substantially completely, is compensated. Drive train according to one of the preceding claims, characterized in that the predetermined temperature range between -40 ° C and +80 ° C. Drive train according to one of the preceding claims, characterized in that at least over the predetermined temperature range a temperature dependency of the length difference (L ₁ -L ₂ ) between the length (L ₁ ) of the first brake housing portion (12a) and the length (L ₂ ) of the second brake housing portion (12b) is opposite to the temperature dependence of the static friction coefficient and / or the sliding friction coefficient between the frictional engagement elements (8, 9, 9, 10). Drive train according to one of the preceding claims, characterized in that the frictional engagement elements (8, 9, 9, 10) each have a friction surface, which are in frictional engagement with each other via the pressing force (F) or can be brought, preferably that at least a part of Frictional engagement elements (8, 9, 10) about an axis of rotation (X) is rotatable, more preferably, that the pressing force (F) relative to the axis of rotation (X) acts axially or radially. Drive train according to one of the preceding claims, characterized in that the frictional engagement mechanism (6) is part of a brake mechanism (7) which acts on a drive component (18) of the drive train (1). Drive train according to one of the preceding claims, characterized in that at least one frictional engagement element (8, 10) is arranged fixed and / or at least one frictional engagement element (9) is rotatable. Drive for the motorized adjustment of a closure element (3) of a motor vehicle, wherein a drive train (1) according to one of the preceding claims is provided. Drive to Claim 12 , characterized in that the drive (2) is designed as a spindle drive and a drive motor (4) and a drive motor (4) downstream spindle-spindle nut transmission (21) with a spindle (22) and an associated spindle nut (23) for generating linear Having drive movements, preferably, that the frictional engagement mechanism (6) of the drive train (1) between the drive motor (4) and the spindle spindle nut transmission (21) is connected. Closure element arrangement of a motor vehicle with a closure element (3) which is adjustably coupled to the body of the motor vehicle and with at least one drive (2) for the motorized adjustment of the closure element (3) Claim 12 or 13 , Closing element arrangement according to Claim 14 , characterized in that the drive (2) is not designed to be self-locking and designed as a braking mechanism (7) frictional engagement mechanism (6) holding the closure element (3) in intermediate positions with the drive (4), preferably that the closure element (3) at switched off drive (4) is manually adjustable against the braking action of the brake mechanism (7).

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