Compact auxiliary drive for a trailer

p0001The invention relates according to the preamble of claim 1 an auxiliary drive for a trailer.

p0002Trailer (vehicle trailer) are usually pulled by tractors. Thus it is known that a car can tow a caravan. If the trailer is detached from the tractor, it is usually moved by hand in the final position. However, followers are now becoming increasingly available in the caravan area, which can be moved due to their size and therefore their weight only with difficulty by hand. Therefore auxiliary drives have been developed that make it possible to move even without a trailer with tractor engine support or to turn.

p0003From the <patcit id="pcit0001" dnum="EP0827898A1"><text>EP 0827898 A1</text></patcit> is an auxiliary drive for a trailer, in which a frame part is fixedly connected to the chassis of the trailer. The frame part carries a movable part relative to the frame support from which in turn a drive motor is held by a drivable by the drive motor driving roller. Further, a movement mechanism is provided for moving the carrier between a rest position in which the drive roller is separated from a tire of the trailer, and a drive position in which the drive roller is pressed against the tire of the wearer. The change of the position of the carrier is carried out manually with the help of a lever which can be attached to the carrier.

p0004In the <patcit id="pcit0002" dnum="EP1203713A1"><text>EP 1203713 A1</text></patcit> describes another auxiliary drive for a trailer but operates on the same principle. However, while the drive roller in accordance with the auxiliary drive<patcit id="pcit0003" dnum="EP0827898A1"><text>EP 0827898 A1</text></patcit> is pivoted about a horizontal axis parallel to the wheel axis, in accordance with the auxiliary drive <patcit id="pcit0004" dnum="EP1203713A1"><text>EP 1203713 A1</text></patcit> a vertical pivot axis provided.

p0005The known auxiliary drives are relatively bulky and, due to their rugged structure on the slope, highly polluting. may be impaired by jammed stones while even the function. The rugged structure also requires a very robust and therefore heavy construction.

p0006From the <patcit id="pcit0005" dnum="US3826324A"><text>US 3,826,324</text></patcit> is a generic auxiliary drive for a trailer, in which a cross-bar is pivotally movable in a pivot bearing. On the cross bar, a drive motor and a transmission is required through which a drive roller for a wheel of the trailer can be driven. The cross bar can be moved with the drive motor and the Getreibe between a rest position in which the drive roller is separated from the wheel of the trailer, and a drive position in which the drive roller is pressed against the wheel of the trailer.

p0007The invention has for its object to provide an auxiliary drive for a trailer, which has a compact design, so that it has a low structural weight and a reduced tendency to soiling.

p0008The object is achieved by an auxiliary drive for a trailer according to claim. 1

p0009According to the invention, an auxiliary drive is provided with a rigidly connectable to a chassis of the trailer support, one relative to the holder movable support, one held by the carrier driving motor, mounted on the carrier, by the drive motor via a gear driven drive roller and with a moving mechanism for moving the carrier between a rest position in which the drive roller is separated from a trailer wheel, and a drive position in which the drive roller is pressed against the wheel of the trailer. The auxiliary drive according to the invention is characterized in that the support comprises an integrated in the carrier gear housing in which the transmission is housed, and that the carrier is designed such that a flow of force, which is caused by a force acting on the drive roller in the driving position operating force and extends to the support, is essentially made completely through the gearbox housing.

p0010The carrier is thus the invention, among other things, the transmission housing is, in turn, is reversed completely integrated into the carrier. Whereas in the prior art, the carrier had to hold the separately provided the gear housing, the gear housing now takes over the supporting function itself by providing at least a substantial part of the power flow is routed via the transmission housing. This allows a very compact construction of the carrier, wherein the gearbox housing does not have to be kept separately.

p0011It is particularly advantageous if the carrier has a base portion. The base portion contacts the holder and is movably guided in the holder. The base portion carries the also the carrier associated gearbox. Thus, the support is substantially comprised of two main components base region and gearbox. Depending on the installation space, the base region than provided under or next to the gear housing.

p0012In a particularly advantageous embodiment of the invention, the components of the auxiliary drive are arranged such that the caused by the operation force power flow components using flowing in the following order: drive roller, drive shaft (the drive roller bears), one or more bearings (the drive shaft in the gearbox store), gearbox, base area and support. The power flow is guided in this way the shortest possible route from the against the wheel pressed and the wheel rotation driving drive roller to the bracket where the power flow is routed through the chassis.

p0013It, when the drive roller is mounted on one side is particularly advantageous. In the prior art, the drive roller is supported by the drive shaft while the drive shaft in turn is supported on at least two bearing points. Now, when the drive roller on the drive shaft according to the invention on one side and overhung gel to at least two bearing points is Agert, this means that the drive roller sits on a free shaft end of the drive shaft and can be easily mounted. The two bearings support the drive shaft on the side facing away from the free shaft end side.

p0014In a particularly advantageous embodiment of the invention, the drive motor is carried by the transmission housing. Thereby, it is possible that no separate support must be provided for the drive motor. Instead, the drive motor can be mounted directly, for example via a motor flange on the carrier or to the transmission housing.

p0015Furthermore, it is advantageous if the driving motor is covered by a likewise fixable to the transmission housing cover. The drive motor can be effectively protected from contamination or mechanical action from outside.

p0016In a particularly advantageous embodiment of the invention, the support consists essentially of two shell-like housing elements, namely a main shell and a lid shell. Of course, other elements can be attributed as part of the carrier. However, let the base area and the gearbox of the carrier realized in a very simple manner by the two housing elements.

p0017It is particularly advantageous if a main parting plane between the two housing elements (or between the main shell and the cover shell) is perpendicular to a rotational axis of the drive roller. Due to the restrictions that exist for the installation of the auxiliary drive to the chassis of the trailer near the driven wheel or the driven wheels, usually only a small installation space is available. This may require each a rectangular configuration of the auxiliary drive, namely in particular a right-angled arrangement of the drive roller and the drive motor. Now, if the main separation plane perpendicular to the axis of rotation of the drive roller, the drive motor can be very easily attached to the transmission housing. The divided by the main plane of separation gearbox is easy to open, to incorporate the transmission components or to wait.

p0018it when the operation force caused by the force flow is guided essentially completely over at least part of the housing elements is particularly advantageous. The housing members thus fulfill a supporting function which is fulfilled by additional ribs or webs of the prior art. In these webs can be dispensed at the auxiliary drive according to the invention.

p0019Preferably, the bracket has two wall elements between which the carrier is movably held. The wall elements flank the carrier, in particular the base region of the wearer and ensure an equally simple and reliable guidance.

p0020Preferably the carrier is relatively linearly movable with respect to the holder. However, other movement possibilities are conceivable, such as in particular a pivoting of the carrier relative to the holder. It may be of advantage if at least one of the wall elements of the holder has a guide groove, in which the carrier is guided linearly. In this way, no additional guidance of the carrier is required.

p0021In a particularly advantageous embodiment of the invention, the Bewegunsgmechanismus has a stop acting between the support and the holder eccentric mechanism, in particular a toggle mechanism. The eccentric mechanism allows a simple mechanical movement of the carrier between the rest position and the drive position. The movement force is applied by an operator, for example by means of an actuating lever.

p0022The toggle mechanism has the further advantage that it ensures in principle two defined end positions, which can be used as a rest position and the drive position of the carrier.

p0023In order to support the movement or fixation of the desired end positions, it is of particular advantage, when the carrier from the rest position is movable in the driving position against the action of a spring which is tensioned between the carrier and the holder. Overcoming the spring force can also support the action of the toggle mechanism.

p0024the fact that the support comprises an integrated spring-receptacle for substantially complete receiving the spring is particularly advantageous. The spring can be accommodated in this way in the support and effective protection against external influences. It may be of advantage if the spring receptacle is formed in one or both of the housing members of the carrier.

p0025It is particularly advantageous here to provide the spring-receiving in the base region of the wearer. In this way, the area occupied by the base portion space exploit well what accomplishment of the goal to provide a particularly compact auxiliary drive promotes.

p0026In another embodiment of the invention the moving mechanism comprises a stop acting between the support and the support spindle drive. The spindle drive may be mechanically, for example by means of a crank to be actuated. Alternatively, however, may be provided for driving a movement spindle, a preferably electrically driven spindle motor.

p0027For the spindle motor, it is particularly advantageous if the carrier has a built-in spindle motor for receiving full receiving the spindle motor. The spindle motor can be integrated into the carrier and be protected against external influences.

p0028Preferably, the spindle motor receptacle is formed in one or both of the housing members of the carrier. The spindle motor intake should be provided in the base region of the support to optimally use the available space there.

p0029In this way, it is possible to completely encase the spindle motor receiving from the environment and to protect the contained inside the support spindle motor.

p0030In an advantageous further development of the invention, the spindle drive has a spindle nut into which the spindle of the motor or a crank rotationally driven by the operator movement spindle can be screwed and which is held by the holder. The bracket is thus to the spindle nut the counter-bearing for the spindle movement is.

p0031In a particularly advantageous embodiment of the invention, the spindle drive including the spindle nut and the spindle movement at least in the rest position is completely sealed off from the environment. The rest position of the auxiliary drive corresponds to a position occupied by the auxiliary drive when the vehicle trailer is pulled by the tractor, for example the car. In this case, often hundreds of kilometers to be traveled under adverse conditions, which causes a considerable contamination of the underbody of the trailer and thus also of the auxiliary drive. If now is encapsulated in this state, namely the rest position of the auxiliary drive, the spindle drive against the environment, the sensitive components and for example, the threaded surfaces of the motion spindle and the spindle nut are protected against external influences.

p0032It is also possible to maintain the complete isolation of the spindle drive against the environment, for example, in the drive position. However, since only a small distance is driven in the operation of the auxiliary drive in the drive position, serious pollution is expected less.

p0033In a particularly advantageous development of the invention, the motion spindle is so screwed into the rest position in the spindle nut that the carrier or the carrier-borne components the holder or held by the holder touch devices. In this way, a defined end position is reached in the rest position. By the contact of carrier and mount a previously existing gap will be closed, in which the movement of the spindle may be located. With the touch of carrier and holder movement spindle in the interior is sealed off from the environment.

p0034It is of particular advantage if the spindle nut is completely on one of the remote Einschraubseite for the movement spindle side is closed, that is sealed or encapsulated. Between the support and the support is advantageously an at least provided in the rest position between the carrier and the holder effective seal that the motion spindle against the environment abkapselt least in the rest position. The seal is held by the carrier or by the holder and seals the space around the motion spindle from when the carrier has the support far enough approximated. The approach can go so far that the support the support - as explained above - affected and therefore the seal comes into effect.

p0035In a particularly advantageous embodiment of the invention in the same space of the eccentric mechanism or the spindle drive can optionally be provided without the housing elements of the carrier must be structurally altered. This makes it possible to make the carrier uniformly and as required with an appropriate or desired by a customer moving mechanism - for example the eccentric mechanism or the spindle drive - equip. At least the main components of the carrier need to not be changed. Can optionally be attached to the main components of the carrier auxiliary components such as bolts, screws or cap in order to adapt the support to the chosen moving mechanism. The same applies to the holder: The holder must in this advantageous embodiment not be structurally altered. It may only be necessary to provide at the location of the motion spindle a pin on which, for example, the spring can be suspended.

p0036In this context, it is of particular advantage if the spring receiving and the spindle motor are the same and recording are selectively usable for accommodating the spring or spindle motor in the carrier.

p0037These and other advantages and features of the invention will be explained in more detail by way of examples with the aid of the accompanying figures. Show it:<dl id="dl0001"><dt><b>Fig. 1</b></dt><dd>an auxiliary drive according to a first embodiment in perspective view;</dd><dt><b>FIGS. 2a and 2b</b></dt><dd>a portion of the auxiliary drive with carrier open;</dd><dt><b>Fig. 3</b></dt><dd>a partial perspective view of the auxiliary drive of <figref idrefs="f0001">Fig. 1</figref>;</dd><dt><b>FIGS. 4a to 4c</b></dt><dd>Sectional views of the auxiliary drive of <figref idrefs="f0001">Fig. 1</figref> in rest position (<figref idrefs="f0004">FIG. 4a</figref>, Top view; <figref idrefs="f0005">Fig. 4b</figref>, Side view) and in driving position (<figref idrefs="f0004">Fig. 4c</figref>, Top view);</dd><dt><b>Fig. 5</b></dt><dd>a partial perspective view of the auxiliary drive according to a second embodiment of the invention;</dd><dt><b>FIGS. 6a and 6b</b></dt><dd>lateral sectional views of the second embodiment, in different operating positions.</dd></dl>

p0038<figref idrefs="f0001">Fig. 1</figref> shows a perspective view of a first embodiment of the auxiliary drive according to the invention for a vehicle trailer.

p0039The auxiliary drive has a holder 1 which can be fixedly connected to a not shown frame of the trailer. For this purpose, the holder has a notch 1 2 which may be fitted onto a square tube or welded to a square tube. The square tube in turn is fixed to the chassis.

p0040The holder 1 consists essentially of two sheet-like wall elements 3, 4, which are mutually parallel mounted on the square tube, not shown.

p0041Between the wall elements 3, 4 of the holder 1, a support 5 is held linearly movable. To this end, four guide grooves 6 are in the wall elements 3, provided, in which connected to the carrier 5 are guide pins 7 back and forth.

p0042The carrier 5 has a base region 8 and an above of the base portion 8 arranged and supported by this gear housing. 9 The base region 8 thus touch the wall elements 3, 4 of the holder 1 and is guided thereby. The base region 8 is thus integrated with the transmission case 9 to the compact support 5 to a unit.

p0043On one side of the gear housing 9, an electric drive motor 10 is held by the gearbox housing. 9 The drive motor 10 is in<figref idrefs="f0001">Fig. 1</figref> concealed by a cover 11 and therefore not visible. The cover 11 can be held by the motor housing of the drive motor 10th However, it can also be attached to the transmission housing. 9

p0044A rotational movement of the drive motor 10 is converted by an element located in the transmission case 9 with respect to transmission speed and the axial direction. In particular, the speed is reduced and redirected the rotation by 90 degrees. Accordingly, 10 extends perpendicular to the motor shaft of the drive motor from the gearbox 9, a drive shaft 12 on which a drive roller is fixed. 13 The drive roller 13 eventually drives an unillustrated wheel of the vehicle trailer. For this purpose, the drive roller 13 on its outer surface a roughened and / or profiled surface, in order to achieve sufficient frictional action between the drive roller 13 and the driven wheel.

p0045The drive roller 13 is mounted on one side on the drive shaft 12th This means that the drive roller 13 is secured on the drive shaft 12 in an area which is outside a range lying between two bearing points on which the drive shaft is mounted in the gear housing 9 12th In this way a floating support is realized. The drive shaft 12 accordingly has a free shaft end, the drive roller 13 in the in<figref idrefs="f0001">Fig. 1</figref> shown manner is axially slid.

p0046The support 5 is movable by means of a moving mechanism relative to the holder the first When in<figref idrefs="f0001">Fig. 1</figref> embodiment shown, the moving mechanism realized as a spindle drive 14, which will be explained later.

p0047With the help of the motion mechanism, it is possible to make the carrier 5 in between an <figref idrefs="f0001">Fig. 1</figref> To move forward position shown (driving position), in which the drive roller 13 is pressed against the wheel of the trailer, and a retracted position (home position), in which the drive roller 13 is separated from the wheel of the trailer. The guide pin 7 accordingly take a front (<figref idrefs="f0001">Fig. 1</figref>) Or a rear position in the corresponding guide grooves. 6

p0048The support 5 is designed such that a flow of force, which is caused by a force acting on the drive roller 13 in the drive position operating force and extends to the holder 1, is passed substantially completely through the gearbox housing. 9 This means that the power flow is transmitted from the drive roller 13 on the drive shaft 12, which is mounted in the transmission housing. 9 The gear housing 9 absorbs the forces acting on the drive roller 13 forces and forwards them into the base region 8, from where the forces are finally transmitted to the holder the first Characterized in that the force flow is conducted completely through the transmission casing, no further supporting elements, such as ribs, webs or support plates are required. Rather, the gearbox, the function of supporting the drive shaft 12 and the drive roller fulfilled except its function as a "transmission housing" itself even 13. This allows a particularly compact, integrated structure, in contrast to the auxiliary drives known from the prior art.

p0049The support 5 also has a very advantageous two-part construction, in particular from <figref idrefs="f0002">FIG. 2</figref> visible. <figref idrefs="f0002">FIG. 2</figref> 5 shows the carrier together with the drive shaft 12 and the drive roller 13 from two different perspective views (<figref idrefs="f0002">FIGS. 2a and 2b</figref>).

p0050The support 5 consists essentially of two shell-like housing elements, namely a main tray 15 and a lid shell 16. The two housing elements 15, 16 are prepared, for example as a cast part together and integrate various functions. In particular, they allow the carrier 5 to accommodate the various other components of the auxiliary drive and stored, such as in particular a provided in the gear housing 9 gearbox 17, to be fastened to an engine mount 18 driving motor 10 and the moving mechanism, the at least partially explained in a later , can be accommodated in the main tray 15 formed recording 19th

p0051In this case is used in particular, the main tray 15 for receiving and supporting the various components, while the lid shell 16 in the <figref idrefs="f0002">FIG. 2b</figref> visible open side of the main tray 15 closes and thus the overall rigidity of the beam 5 increases significantly and ensures adequate protection of the components. A seal may be provided between the main shell 15 and the lid shell 16 to prevent the ingress of dirt and moisture.

p0052<figref idrefs="f0003">Fig. 3</figref> showing the first embodiment of the invention in a fragmentary perspective view. In particular, the drive motor 10, the lid shell 16 and the wall element 4 has been omitted to ensure recognize additional details can.

p0053As moving mechanism of the spindle drive 14, which includes a spindle motor 20, a rotatably driven by the spindle motor 20 and a motion spindle 21 held by the holder 1 spindle nut 22, into which the movement spindle 21 is screwed which serves.

p0054The spindle motor 20 is installed in the receptacle 19 of the support 5, which is frontally closed by a cover 23rd Accordingly, the spindle motor 20 with a closed carrier 5 is completely sealed off from the environment. Only the movement of spindle 21 is located outside and can be screwed into the spindle nut 22nd

p0055To compensate for misalignment, the spindle nut 22 is pivotally supported on the wall elements 3, 4 of the bracket. 1 The spindle nut 22 is so far represents a part of the holder. 1 Furthermore, the spindle nut 22 is closed at its the Einschraubseite for the motion spindle 21 opposite side by a cap 24th

p0056The <figref idrefs="f0003">Fig. 3</figref> shows the support in the extended position, ie in the drive position. When the carrier is moved back by rotating the movement screw 21, it is possible to return the support 5 so far that the in<figref idrefs="f0003">Fig. 3</figref> still exposed area is closed to the movement of the spindle 21 by the support 5, the spindle nut 22 abuts against the holder 1 or. This can be completely encapsulated from the environment in the rest position of the spindle drive 14 including spindle nut 22 and the motion spindle 21st The support 5 carries a sealing ring 25, which is pressed against the spindle nut 22 and thus the in<figref idrefs="f0003">Fig. 3</figref> exposed region of the spindle drive 14 completely abkapselt against the environment.

p0057In another, not illustrated embodiment of the invention, a flexible bellows is arranged between the support 5 and the holder 1 that adjusts its length as a function of the relative position between the support bracket 5 and the first

p0058On the drive shaft 12 is in <figref idrefs="f0003">Fig. 3</figref> Moreover, a roller bearing 26 recognizable.

p0059<figref idrefs="f0003">Fig. 3</figref> granted beyond insight into the gear 17, which deflects the rotation of the first drive motor via a worm gear and then reduced via a spur gear in terms of speed and by 90 degrees.

p0060The encapsulate of the spindle drive 14 against the environment is based on the <figref idrefs="f0004">FIGS. 4a to 4c</figref> clarified.

p0061<figref idrefs="f0004">FIG. 4a</figref> shows a section through the drive spindle 14 in the plan view, the carrier 5 is in rest position. <figref idrefs="f0005">Fig. 4b</figref> is the associated sectional representation in side view. <figref idrefs="f0004">Fig. 4c</figref> equals to <figref idrefs="f0004">FIG. 4a</figref>But with the carrier in the extended drive position.

p0062In the <figref idrefs="f0004">FIG. 4a</figref> it can be seen that the movement of spindle 21 is fully screwed into the spindle nut 22, so that the carrier 5 is moved back so far that it abuts against the holder first The sealing ring 25 is pressed against the spindle nut 22nd

p0063Since the auxiliary drive is normally located in this position when the vehicle trailer is pulled by the tractor, the spindle drive 14 is effectively protected against external influences. The motion spindle 21 is only exposed when the auxiliary drive is used and is in drive position. Then, however, the risk of contamination is significantly lower, not least because of the presumably comparatively short driveways and low speeds.

p0064In the illustration in <figref idrefs="f0004">Fig. 4c</figref> is the movement screw 21 unscrewed from the spindle nut 22, so that the support 5 is displaced forwardly in the driving position. Accordingly, the seal 25 loses its effect and gives the space to the motion spindle 21 free.

p0065<figref idrefs="f0003">Fig. 5</figref> shows a second embodiment of the invention in a fragmentary perspective view. In particular, the drive motor 10, the lid shell 16 and the wall element 4 has been omitted to ensure recognize additional details can.

p0066In the second embodiment of the invention the movement mechanism is designed as a cam lever mechanism in the form of a toggle mechanism.

p0067To this end, of the holder 1, a switching shaft mounted pivotably 27, at one end of a square 28 is formed, on which a switching crank or a lever can be mounted.

p0068On the shift shaft 27, an eccentric 29 is fixed, to which one end of a shift lever 30 is pivotally connected. The other end of the shift lever 30 is hinged to the base portion 8 of the carrier fifth

p0069Between the front guide pin 7 of the carrier 5 and held by the holder 1 holding pin 31 a tension spring 32 is stretched.

p0070The function of the toggle mechanism is based on the <figref idrefs="f0006">FIGS. 6a and 6b</figref> explained.

p0071<figref idrefs="f0006">Fig. 6a</figref> shows a longitudinal sectional view of the second embodiment of the invention, with the support 5 is in rest position.

p0072Accordingly, the switching shaft 27 is pivoted with the eccentric 29 to the rear, so that a connecting joint 33 between the eccentric 29 and the shift lever 30 is also behind.

p0073<figref idrefs="f0006">Fig. 6b</figref> shows the carrier-to-analog <figref idrefs="f0006">Fig. 6a</figref> in the shifted forward drive position.

p0074To this end, the stem 27 has been pivoted to the eccentric 29 about a pivot angle of approximately 170 degrees. Thereby, the connecting link 33 and the shift lever 30 is also moved forward, so that they push the carrier 5 forwardly. By this movement, the tension spring 32 is tensioned.

p0075By the eccentric 29 and the shift lever 30, a toggle lever is formed. Characterized in that the eccentric 29 is pivoted over the dead center of the toggle lever addition (<figref idrefs="f0006">Fig. 6b</figref>), Effects the tensioned in the driving position the tension spring 32 to stabilize the position of the carrier 5. The carrier 5 is locked and generates a sufficiently grolie pressing force of the drive roller 13 against the wheel. Only by pivoting back of the eccentric 29, the support 5 in the rest position be pushed back.

p0076In the <figref idrefs="f0006">FIGS. 6a and 6b</figref> a square tube is 34 can be seen in sectional view in addition, the above in connection with <figref idrefs="f0001">Fig. 1</figref> (There not shown) has been described, and to which the holder is attached 1.

p0077A comparison of the <figref idrefs="f0003">FIGS. 3 and 5</figref> indicates that the carrier 5, in particular its main shell 15 has remained unchanged. At the holder 1 optionally the retaining bolt 31 or the spindle nut 22 can be secured. It is thus possible, the toggle mechanism or the spindle drive 14 installed without changing the design of holder 1 or 5 as a carrier moving mechanism either, depending on the equipment request of the user.