DE102020111434A1 - Drive unit and rollable platform - Google Patents

Abstract

The disclosure relates to a drive unit with a drive wheel (146, 246, 346, 446, 546) that can be driven by an electric motor, in particular a fifth wheel, for a rollable platform (12), with a base (142, 242, 342, 442, 542) , which can be coupled to a rollable platform (12), a drive wheel (146, 246, 346, 446, 546) that can be driven by an electric motor and that moves in a first direction of travel (130, 230, 330, 430, 530) and a second, opposite direction of travel ( 132, 232, 332, 432, 532) is drivable, a biasing element (154, 254, 354, 454, 554) to increase a contact pressure (176, 276, 376, 476, 576) on the drive wheel (146, 246, 346 , 446, 546), at least one wheel carrier (150, 250, 350, 450, 550) between the base (142, 242, 342, 442, 542) and the drive wheel (146, 246, 346, 446, 546) is arranged, the wheel carrier (150, 250, 350, 450, 550) moving relative to the base (142, 242, 342, 442, 542) against a force applied by the prestressing element (154, 254, 354, 454, 554) is the same, whereby in the first direction of travel (130, 230, 330, 430, 530) the drive torque applied to the drive wheel (146, 246, 346, 446, 546) increases the contact pressure (176, 276, 376, 476, 576) causes, and wherein a torque support (170, 270, 370, 470, 570) with at least one support element (190, 290, 390, 490, 590), which is a during operation of the drive unit in response to the drive torque on the drive wheel (146, 246 , 346, 446, 546) acting counter-torque (188, 288, 388, 588) is supported in such a way that the counter-torque (188, 288, 388, 588) when driving in the second direction of travel (132, 232, 332, 432, 532) contributes to maintaining the contact pressure (176, 276, 376, 476, 576). The disclosure also relates to a platform trolley (10) and the use of a drive unit as a conversion kit.

Description

The present disclosure relates to a drive unit for a rollable platform and to a rollable platform provided with such a drive unit. The present disclosure also relates to the use of a drive unit for motorizing a rollable platform.

From the EP 1 003 663 B1 a manually movable trolley is known, which has a chassis equipped with four swivel castors and is provided with a sliding device and a parking device, with a support section located below the parking device, on which at least one wheel is arranged, which is located between two front and two rear castors is located, and an electromotive drive unit for driving the at least one impeller is provided on the support section.

From the EP 3 202 636 A1 a similarly designed transport device is known, with a drive unit in the form of a drive rocker which is provided with a drive wheel.

Rollable platforms within the meaning of the present disclosure are designed, for example, as transport trolleys, transport platforms, platform trolleys, patient supports, workshop trolleys, transport trolleys and the like.

Such platforms usually have four rollers or wheels, which can also be referred to as castors. The use of four wheels, which are assigned to four corners of the platform by way of example, is widespread. However, this is not to be understood as restrictive.

For example, two of the four roles are designed as so-called steering castors and two of the four roles as fixed (non-steerable) roles. Non-steerable castors are commonly referred to as fixed castors. However, designs with four steerable rollers or wheels are also conceivable. It is also conceivable to make the rollers or wheels steerable and not steerable, if necessary, by locking or unlocking a steering axle.

Drive units are known which are referred to and used as so-called fifth wheels. Such a fifth wheel is designed as a drive unit, for example, in order to provide a rollable platform with four wheels with a drive. Something like this is conceivable in the field of logistics, for example, in order to be able to move pallet trolleys with motor assistance. Another conceivable application is the movement of patient supports, beds and the like in the health sector.

Motor-assisted operation can, on the one hand, include complete drive of the platform by the fifth wheel. However, it is also conceivable that the fifth wheel only makes a contribution to the propulsion in order to relieve the operator.

The fifth wheel is usually placed between two fixed castors. However, this is not to be understood as restrictive.

A fifth wheel is designed, for example, as a retrofit solution or conversion solution, so that rollable platforms can be converted or upgraded for motorized movement as required. This has the advantage that no or only minor structural changes have to be made to the basic structure of the rollable platform. Another advantage can be seen in the standardization. Rollable platforms (in logistics or in the health sector) are usually provided with standardized requirements for cargo, patients and the like. The dimensions up to the chassis are also often standardized.

The use of a fifth wheel as required now allows such a standardized platform to be motorized. It is conceivable to design the fifth wheel as a structural unit or a conversion solution, with the drive, power transmission, energy storage and possibly even the control being combined in one unit or module, depending on the application.

A corresponding drive unit can in principle be used for forward travel and reverse travel. The drive unit can also be used to support regenerative braking.

The behavior of the fifth wheels is usually directional. A common embodiment is the design as a set of rockers. In other words, the caster is rotatably arranged on a spring-loaded rocker that extends between the caster and a bearing point on the platform. The platform-side bearing of the rocker is arranged in the direction of travel (main direction of travel) in front of the bearing for the caster at the opposite end of the rocker.

A spring or some other biasing element presses the rocker and consequently the castor against the ground. In the given configuration, the pressing force on the caster increases during the forward movement, since a counter-torque that occurs in response to the drive torque acts on the rocker in such a way that it also presses the caster downwards.

In general, the contact pressure, i.e. the force with which the castor is pressed onto the ground, must be taken into account when operating the fifth wheel and the platform provided with it.

During operation, when using the rollable platform, the weight often fluctuates. There are clear differences, for example, between a loaded and an unloaded state.

If the contact pressure is too low, the drive wheel of the rollable platform will slip. In other words, the drive wheel spins prematurely. If, on the other hand, the contact pressure is too high, the drive unit relieves the adjacent rollers / wheels on the platform excessively. This can go so far that these rollers / wheels lose contact with the ground. Then the platform can even tip over. A case-dependent adjustment of the contact force would involve a certain amount of effort and is therefore often avoided.

Furthermore, it has been shown that the drive behavior and in particular the contact pressure on the drive wheel are often direction-dependent in the case of solutions known in the prior art. In other words, the contact pressure on the drive wheel changes regularly with changes in direction, possibly even to an intolerable extent. Under certain circumstances, this can lead to the drive wheel spinning prematurely when reversing. On the other hand, if the contact pressure is too high when driving forwards, rollers / wheels in the vicinity of the drive wheel can lose their grip. This can lead to instability and uncontrolled behavior.

Against this background, the disclosure is based on the object of specifying a drive unit with an electric motor-driven drive wheel that can be used for motorizing a rollable platform, the drive unit enabling the most predictable and controllable operating states possible both when driving forward and when driving backward. In particular, the drive unit should be designed in such a way that the contact pressure on the drive wheel does not fall below a certain minimum level both when driving forwards and when driving backwards. The drive unit preferably enables an increase in the contact pressure that is dependent on the applied drive torque, at least when driving forward, which improves the traction. The drive unit should be able to be installed and retrofitted with as little additional effort as possible. The drive unit should be as simple as possible to control and operate, regardless of the current direction of travel. Finally, the drive unit is intended to help reduce the stress on operators of rollable platforms when moving the platforms. This preferably relates to the expenditure of force, more preferably also to the expenditure of controlling the drive unit and the expenditure of controlling the maneuvering.

Finally, within the scope of the present disclosure, a rollable platform is to be specified which is provided with such a drive unit.

In addition, a use of a drive unit for motorizing a rollable platform should be specified within the scope of the present disclosure.

• - eine Basis, die mit einer rollbaren Plattform koppelbar ist,
• - ein elektromotorisch antreibbares Antriebsrad, das in einer ersten Fahrtrichtung und einer gegensinnigen zweiten Fahrtrichtung antreibbar ist,
• - ein Vorspannelement zur Erhöhung einer Anpresskraft auf das Antriebsrad,
• - zumindest ein Radträger, der zwischen der Basis und dem Antriebsrad angeordnet ist,
  • wobei der Radträger gegen eine vom Vorspannelement aufgebrachte Kraft relativ zur Basis beweglich ist,
  • wobei in der ersten Fahrtrichtung das am Antriebsrad anliegende Antriebsmoment eine Erhöhung der Anpresskraft bewirkt, und
• - eine Momentenabstützung mit zumindest einem Stützelement, die ein beim Betrieb der Antriebseinheit in Reaktion auf das Antriebsmoment am Antriebsrad wirkendes Gegenmoment derart abstützt, dass das Gegenmoment bei Fahrt in der zweiten Fahrtrichtung zur Aufrechterhaltung der Anpresskraft beiträgt.

According to a first aspect, the present disclosure relates to a drive unit with a drive wheel that can be driven by an electric motor, in particular a fifth wheel, for a rollable platform, the drive unit having the following:

• - a base that can be coupled to a rollable platform,
• - a drive wheel that can be driven by an electric motor and that can be driven in a first direction of travel and a second direction of travel in the opposite direction,
• - a preload element to increase a contact pressure on the drive wheel,
• - at least one wheel carrier, which is arranged between the base and the drive wheel,
  • wherein the wheel carrier is movable relative to the base against a force applied by the biasing element,
  • wherein in the first direction of travel the drive torque applied to the drive wheel causes an increase in the contact pressure, and
• - A torque support with at least one support element that supports a counter-torque acting in response to the drive torque on the drive wheel during operation of the drive unit in such a way that the counter-torque contributes to maintaining the contact pressure when driving in the second direction of travel.

The object on which the disclosure is based is completely achieved in this way.

According to the invention, a motorized support can be provided in this way for the movement of the rollable platform both when driving forwards and when driving backwards. In particular, a sufficiently predictable and easily controllable behavior results in both directions of travel, at least in exemplary embodiments.

The first direction of travel is, for example, the direction of travel for forward travel. The second direction of travel is, for example, the direction of travel for reverse travel. However, this is not to be understood as restrictive; the reverse assignment is also conceivable.

The drive unit has, for example, a drive wheel with a motor lying on it. Such a drive wheel needs a torque support in order to be able to transmit the drive force or the drive torque. This torque support can be provided directly or indirectly by the wheel carrier. Since the wheel carrier is movable relative to the base, there are regular effects on the contact pressure.

In other words, the drive torque or the thrust force influences the resulting contact pressure that presses the drive wheel against the ground (ground, road, etc.).

In an exemplary embodiment, the (downwardly directed) contact pressure is proportional or approximately proportional to the thrust force or the drive torque. This preferably applies both in the first direction of travel and in the second direction of travel.

According to further exemplary embodiments, the operating behavior of the drive unit is at least improved if, in the second direction of travel, the contact pressure is not excessively reduced with increasing thrust or increasing drive torque. In this way, a contribution can be made to maintaining the contact pressure in the various operating states.

According to the invention, the drive unit is designed in such a way that a minimum level of contact pressure is maintained not only when driving forward but also when driving backward.

In the context of the present disclosure, maintaining the contact force is to be understood as an increase in the contact force due to the torque support in the respective direction of travel. However, configurations are also conceivable in which the torque support is designed in such a way that a minimum level of contact pressure is maintained as a function of the thrust force (of the drive torque).

In other words, the contact pressure drops to a lesser extent than would be the case without the design and torque support according to the disclosure.

It was recognized that in conventional drive units, in particular those with a simple rocker arrangement, the directional dependency is the cause of various disadvantages. The directional dependency can be traced back to the fact that, with the usual swing arm arrangement, the counter-torque acting on the swing arm when applying a drive torque in one driving situation (e.g. driving forward) tends to increase the contact pressure and in another driving situation (e.g. backward driving) the contact force tends to decrease.

For example, the torque support according to the disclosure is designed in such a way that when reversing - in contrast to drive units from the prior art, which are arranged on a simple rocker without additional torque support - the contact pressure generated by the pretensioning element is not reduced but even increased.

However, it is also conceivable to design the drive unit and its torque support in such a way that, when reversing, the contact pressure generated by the prestressing element is reduced, but a minimum level of contact force is maintained.

The platform is, for example, a mobile platform provided with four wheels or rollers. The platform is exemplarily designed as a transport platform, platform trolley, patient support, workshop trolley, transport trolley and the like.

The drive unit is designed, for example, as a retrofit or upgrade solution. However, it is also conceivable to integrate the drive unit into the rollable platform right from the start.

In an exemplary embodiment, the drive unit is designed to be installed as a fifth wheel in a rollable platform that has four non-driven wheels (or rollers). In an exemplary embodiment, the drive unit, in particular its drive wheel, is arranged between two non-pivotable wheels in a parallel alignment to them. Non-swiveling wheels or castors are referred to as fixed castors, for example. On the other hand, steerable wheels or rollers are referred to as swivel castors, for example. This is not to be understood as restrictive.

The basis forms a frame or a frame of the drive unit. In particular if the drive unit can be mounted on the platform in a modular manner, the base can serve as a self-supporting frame. This is not to be understood as restrictive. In principle, it is also conceivable to design the base as part of the platform, in particular as part of a platform floor. In such a case, the platform floor ensures the stability of the Drive unit if it is attached to the floor of the platform.

It goes without saying that the drive unit can be designed and dimensioned in such a way that the rollable platform can be moved completely by the drive unit. However, it is also conceivable to design the drive unit to assist in the movement of the rollable platform.

It goes without saying that, for example, two drive wheels connected to one another are also conceivable, in the manner of twin tires.

It goes without saying that different elements of the drive unit can be provided twice in order to maintain symmetry and to avoid undesirable tilting moments about an axis perpendicular to the axis of the drive wheel. This applies, for example, to elements of the torque support, for example to support elements. Furthermore, this can apply to the wheel carrier. In addition, this can apply to the prestressing element. However, this is not to be understood as restrictive. It goes without saying that, depending on the design, the desired behavior of the drive unit can also be achieved with only one preload element, only one wheel carrier and, if necessary, only one support element of the torque support, in particular the desired increase in the contact force in both the first and the second direction of travel .

The base can be designed as a component of the platform, at least in exemplary embodiments. In further exemplary configurations, the base is part of a separate drive unit that is mounted on the platform. Mixed forms are conceivable in which the base is formed partly by the platform and partly by originally separate elements of the drive unit after the drive unit has been installed.

According to an exemplary embodiment, the torque support is designed in such a way that the counter-torque generated during operation of the drive unit generates a force component on the wheel carrier both in the first direction of travel and in the second direction of travel, which together and in the same amount as the force generated by the pretensioning element to increase the Contact pressure contributes.

In other words, the torque support according to this embodiment is designed in such a way that the counter-torque or the counter-force is absorbed in response to the drive torque or the thrust force and derived via the wheel carrier that a force component in the same direction arises as a result in both directions of travel Driving force increased.

According to a further exemplary embodiment, the torque support comprises at least one support element which is coupled to the drive wheel and can be pivoted relative to the wheel carrier. The at least one support element serves to absorb the counter-torque that occurs when the drive wheel is driven. In other words, the at least one support element serves as a torque support for the direct or indirect support of a drive motor for the drive wheel.

If the support element can be pivoted relative to the wheel carrier, two orientations of the support element with respect to the wheel carrier can result, one of which is assigned to the first direction of travel and another to the second direction of travel.

For example, the at least one support element is connected in a rotationally fixed manner to a stator of a motor of the drive wheel. In an exemplary embodiment, the drive wheel has a motor integrated into the wheel body, the stator of which is connected in a rotationally fixed manner to an axle of the drive wheel. During the assembly of the drive wheel, the axle can be pivoted within defined limits via at least one support element of a torque support, but apart from that it is non-rotatably mounted on the wheel carrier.

According to a further exemplary embodiment, the at least one support element can be pivoted between a first stop and a second stop relative to the wheel carrier. In this way, forces and moments from the at least one support element can be introduced into the wheel carrier at different positions. This can be used for the desired influencing of the contact pressure.

The pivoting movement between the first stop and the second stop comprises, for example, a maximum of 45 °, according to a further embodiment a maximum of 30 °, according to a further embodiment a maximum of 15 °. In this way, the drive unit can quickly adapt to changed operating conditions, for example a change between the first and the second direction of travel.

According to a further exemplary embodiment, the at least one support element is supported on the first stop in the first direction of travel and on the second stop in the second direction of travel. In this way, the counter-torque, which basically has an orientation (clockwise / counterclockwise) that changes depending on the direction of travel, is introduced into the wheel carrier via the first stop or the second stop, depending on the direction of travel so that there is a favorable force component both in the first direction of travel and in the second direction of travel.

According to a further exemplary embodiment, the pivoting movement of the at least one support element during the movement between the first stop and the second stop changes a lever for introducing the counter-torque into the wheel carrier.

As a result, the resulting force or its direction changes in relation to the counter-torque. In an exemplary embodiment, the resultant force contains a downwardly directed component to increase the contact pressure, both in the case of a counter-torque effective in the clockwise direction and a counter-torque effective in the counterclockwise direction.

According to a further exemplary embodiment, the at least one support element is designed as a rocking lever with two arms which are each assigned to a stop. According to further exemplary configurations, the at least one support element is designed in a V-shaped or U-shaped manner. The tips of the V or U are each assigned a stop. Alternatively, the support element has two arms which, starting from a pivot axis of the support element, are oriented facing away from one another. Mixed forms are also conceivable, for example as a wide V with an obtuse opening angle. In the center, the support element is coupled to the drive wheel, at least in exemplary configurations.

According to a further exemplary embodiment, at least one arm of the rocking lever allows the effective lever length to be adjusted. For example, the arm has two or more receptacles for a stop bolt. Other implementations are conceivable.

It goes without saying that the wheel carrier or the base can also be designed in such a way that the effective lever length can be varied. In this way, the drive unit can be adapted to a given application.

According to a further exemplary embodiment, at least one arm of the rocker arm interacts with a push rod pivotably mounted on the base, the arm of the swivel lever coming to rest directly or indirectly against a stop on the push rod in a stop position, and the arm of the swivel lever in the opposite stop position is removed from the stop of the push rod.

If the pivot lever is in the opposite pivot position, the push rod is inoperative.

According to a further exemplary embodiment, the push rod comprises a piston-cylinder guide or a translational link guide, which in the second pivot position provide the second stop for the support element.

In other words, the push rod is formed, for example, by a cylinder and a rod dipping into it, which acts as a piston. The rod dips into the cylinder when the support element moves towards the second pivot position. The permitted immersion depth or a stop limiting it act as a second stop.

In another embodiment, the push rod has an elongated eye (elongated hole or a fork open on one side) in which a coupling element can be moved in a translatory manner. In the second pivot position, the coupling element comes to a stop at one end of the eye.

According to a further exemplary embodiment, the base, the at least one wheel carrier, the at least one support element and the push rod together form a four-bar chain when the at least one support element rests on the second stop.

In other words, the coupling mechanism formed in this way behaves, for example, like a double rocker, at least in this state.

According to a further exemplary embodiment, the wheel carrier comprises at least one rocker that is pivotably mounted on the base against a prestressing force applied by the at least one prestressing element, the at least one rocker having a pivot axis that is parallel to an axis of rotation of the drive wheel. In other words, the drive wheel and the at least one support element are mounted on the at least one rocker. The drive wheel and the at least one support element are connected to one another in a rotationally fixed manner and can be pivoted together relative to the rocker.

The wheel carrier can in principle be part of a coupling mechanism with several coupling links. The coupling mechanism is designed in such a way that the desired contact pressure is obtained in both directions of travel, if possible.

According to a further exemplary embodiment, the at least one rocker represents a first stop for the support element ready, in particular an effective stop in the first direction of travel.

According to a further exemplary embodiment, the drive unit comprises at least one first rocker and at least one second rocker offset with respect to the first rocker, wherein the at least one first rocker and the at least one second rocker are each mounted on the base, and where pivot axes of the first rocker, the second rocker and the at least one support element are parallel to each other and spaced from each other.

According to a further exemplary embodiment, the first rocker provides a first stop for the support element for the first direction of travel, the second rocker providing a second stop for the support element for the second direction of travel.

In other words, the caster is not only received on one side on the base or the platform via a rocker, but on both sides. The castor is arranged between the two pivot points of the swing arm on the base.

According to a further exemplary embodiment, the first rocker and the second rocker can be pivoted together. In an exemplary embodiment, the first rocker and the second rocker can be pivoted in opposite directions. In a further exemplary embodiment, at least the first rocker or the second rocker has a longitudinal guide to compensate for changes in the center distance. I. E. in other words, the first rocker can be pivoted clockwise, while at the same time the second rocker can be pivoted counterclockwise, and vice versa.

The axis of the drive wheel that is non-rotatably connected to the support element is mounted, for example, in at least one elongated hole in one of the two rockers or in one elongated hole in each of the two rockers. The opposite, facing away bearing point of the two rockers is fixed to the frame in this exemplary embodiment, so that the effective rocker length changes during the joint pivoting movement. As a result, in an exemplary embodiment, the drive wheel is moved essentially vertically when the two rockers are pivoted relative to the base.

According to a further exemplary embodiment, the first rocker and the second rocker are positively coupled via a coupling piece in order to move in the same direction, preferably also in the same amount, relative to the base Support element is used.

In this way, for example, a parallel guide for the link guide can be provided. In other words, the link guide is moved parallel to the base when the first rocker and the second rocker move synchronously, at least in exemplary embodiments.

In an exemplary embodiment, the first rocker and the second rocker are designed similar or even identical, the effective length of the coupling piece between the coupling points with the first rocker and the second rocker being the effective length of the link guide between its coupling points with the first rocker and the second Swing arm corresponds.

According to a further exemplary embodiment, the wheel carrier comprises at least one lifting carrier which is movable along a lifting guide against a prestressing force applied by the at least one prestressing element relative to the base. According to this embodiment, the lifting beam is primarily part of a vertical guide. According to a further exemplary embodiment, the wheel carrier holds a link guide which serves as a guide for the support element.

According to a further exemplary embodiment, the link guide has a first link for a first arm of the support element and a second link for a second arm of the support element, the first link and the first arm having a first stop for the first direction of travel and the second link and the second arm form a second stop for the second direction of travel.

According to a further exemplary embodiment, the first link and the second link allow a pivoting movement of the support element between the first stop and the second stop.

It goes without saying that the pivoting movement is not necessarily to be understood as a pure rotary movement. Instead, the movement can also include translational components. Nevertheless, the pivoting movement includes a tilting of the support element between the two stops in response to the opposing holding torques when moving in the first direction of travel and the second direction of travel.

For example, both the first link and the second link each have an upper stop that acts as a temporary pivot bearing for the pivoting movement of the support element, in particular the opposite arm of the support element is used in the opposite gate.

According to a further exemplary embodiment, the support element is pretensioned in the link guide in the direction of a neutral position. In other words, according to an exemplary embodiment, at least one additional prestressing spring is provided, which aligns the support element centrally with respect to the link guide.

According to a further exemplary embodiment, a reversal of the pivoting movement of the support element in the link guide is made possible when both arms of the support element each come to rest on the stop in the associated link.

According to a further exemplary embodiment, the at least one prestressing element extends between the base and the wheel carrier, a force generated by the at least one prestressing element tensioning the base and the wheel carrier relative to one another. The at least one prestressing element is, for example, a spring, for example a helical spring designed as a tension spring or a compression spring. Other designs are conceivable.

According to an exemplary embodiment, the at least one prestressing element nestles against the base. In an exemplary embodiment, the at least one prestressing element is oriented essentially horizontally and is arranged adjacent to the base. In exemplary embodiments, the essentially horizontal orientation is due to the fact that the spatial position of the articulation points changes due to the spring movement, so that the prestressing element can also have a slight inclination and displacement compared to the original orientation.

It goes without saying that the drive unit can be designed partially or completely symmetrically, at least in exemplary configurations. In other words, essential structural elements of the drive unit can be provided twice and arranged on the right and left of the drive wheel. Accordingly, two wheel carriers, two support elements, two prestressing elements, etc. can be provided. Other designs and also one-sided arrangements are conceivable.

According to a further aspect, the present disclosure relates to a platform trolley with a rollable platform for receiving a load, four or more rollers that are assigned to corners of the platform, and with a drive unit according to at least one exemplary embodiment described herein.

In this way, too, the object of the disclosure is completely achieved.

In an exemplary embodiment, the drive unit is arranged under the platform truck without a steering function. In other words, the drive unit with its drive wheel is designed similar to a fixed castor, that is, it cannot be pivoted about a vertical axis.

In an exemplary embodiment, the drive unit is arranged in such a way that the drive wheel is arranged adjacent to and parallel to an axis formed by two fixed castors of the platform trolley.

Depending on the actual configuration, the axis of the drive wheel can coincide with the axis formed by the two fixed castors. However, embodiments with mutually offset parallel axes are also conceivable.

In the lateral extension (axial extension), the drive unit with the drive wheel is arranged, for example, between the two fixed castors. In one embodiment, the drive wheel is arranged centrally between the two fixed castors. In this way, the drive unit has no critical influence on the steering behavior of the platform trolley.

According to a further aspect, the present disclosure relates to a use of a drive unit according to at least one embodiment described herein as a conversion kit for motorizing a rollable platform.

In this way, too, the object of the disclosure is completely achieved.

For example, a rollable platform which initially has four rollers or wheels results in a design with a total of five wheels, the drive unit being referred to as what is known as the fifth wheel.

According to an exemplary embodiment, the drive unit has a modular design and is provided with a motor, an energy store and a controller. In this way, the drive unit can be designed as a compact unit and can be mounted on a rollable platform with little effort.

The drive unit can be controlled via operating elements. As an example, control elements for forward travel, reverse travel and support torque / thrust force can be provided.

In principle, it is also conceivable to control the drive unit via integrated sensors. For example, manual thrust can be detected in this way, whereupon the drive unit can intervene in a supporting manner.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or on their own, without departing from the scope of the present disclosure.

• 1: eine perspektivische Ansicht einer Ausführungsform eines Plattformwagens, von unten her;
• 2: eine seitliche teilweise gebrochene Ansicht eines Plattformwagens, der mit einer Antriebseinheit in Form eines fünften Rades versehen ist;
• 3: eine schematische Seitenansicht einer Antriebseinheit, in einem ersten Betriebszustand;
• 4: eine weitere schematische Seitenansicht der Antriebseinheit gemäß 3, in einem zweiten Betriebszustand;
• 5: eine perspektivische Ansicht einer beispielhaften Ausführungsform einer offenbarungsgemäßen Antriebseinheit;
• 6: eine schematische Seitenansicht der Gestaltung gemäß 5, in einem ersten Betriebszustand;
• 7: eine weitere Seitenansicht auf Basis von 6, zur Veranschaulichung eines zweiten Betriebszustandes;
• 8: eine perspektivische Ansicht einer weiteren beispielhaften Ausführungsform einer offenbarungsgemäßen Antriebseinheit;
• 9: eine schematische Seitenansicht der Gestaltung gemäß 8, zur Veranschaulichung zweier Betriebszustände;
• 10: eine perspektivische Ansicht einer weiteren beispielhaften Ausführungsform einer offenbarungsgemäßen Antriebseinheit;
• 11: eine schematische Seitenansicht der Gestaltung gemäß 10, in einem ersten Betriebszustand;
• 12: eine weitere Seitenansicht auf Basis von 11, wobei aus Veranschaulichungsgründen Komponenten ausgeblendet sind;
• 13: eine perspektivische Ansicht einer weiteren beispielhaften Ausführungsform einer offenbarungsgemäßen Antriebseinheit;
• 14: eine schematische Seitenansicht der Gestaltung gemäß 13, zur Veranschaulichung zweier Betriebszustände;
• 15: eine perspektivische Ansicht einer weiteren beispielhaften Ausführungsform einer offenbarungsgemäßen Antriebseinheit;
• 16: eine weitere perspektivische, explodierte Teilansicht der Gestaltung gemäß 15, wobei aus Veranschaulichungsgründen Komponenten ausgeblendet sind; und
• 17: eine schematische Seitenansicht der Gestaltung gemäß 15 und 16, zur Veranschaulichung von Betriebszuständen.

Further features and advantages of the disclosure emerge from the following description and explanation of several exemplary embodiments with reference to the drawings. Show it:

• 1 : a perspective view of an embodiment of a platform trolley, from below;
• 2 : a side partially broken view of a platform trolley, which is provided with a drive unit in the form of a fifth wheel;
• 3 : a schematic side view of a drive unit, in a first operating state;
• 4th : a further schematic side view of the drive unit according to FIG 3 , in a second operating state;
• 5 : a perspective view of an exemplary embodiment of a drive unit according to the disclosure;
• 6th : a schematic side view of the design according to FIG 5 , in a first operating state;
• 7th : Another side view based on 6th , to illustrate a second operating state;
• 8th : a perspective view of a further exemplary embodiment of a drive unit according to the disclosure;
• 9 : a schematic side view of the design according to FIG 8th , to illustrate two operating states;
• 10 : a perspective view of a further exemplary embodiment of a drive unit according to the disclosure;
• 11 : a schematic side view of the design according to FIG 10 , in a first operating state;
• 12th : Another side view based on 11 , whereby components are hidden for reasons of clarity;
• 13th : a perspective view of a further exemplary embodiment of a drive unit according to the disclosure;
• 14th : a schematic side view of the design according to FIG 13th , to illustrate two operating states;
• 15th : a perspective view of a further exemplary embodiment of a drive unit according to the disclosure;
• 16 FIG. 12 is another perspective, exploded partial view of the design according to FIG 15th , whereby components are hidden for reasons of clarity; and
• 17th : a schematic side view of the design according to FIG 15th and 16 , to illustrate operating states.

1 uses a perspective representation to illustrate an overall with 10 designated platform truck. It goes without saying that the design of the car 10 is merely exemplary in nature and is primarily used for illustration. In the exemplary embodiment, the car 10 one platform 12th on, which is designed to absorb loads.

The platform 12th stands on roles 16 , 18th , 20th , 22nd . In the exemplary embodiment, the roles are 16 , 18th designed as swivel castors. The roles 20th , 22nd are designed in the embodiment as fixed castors, so as non-steerable roles. That way the cart can 10 be maneuvered. The fixed castors (fixed castors) 20th , 22nd are concentric to an axis 24 aligned. Parallel to this axis 24 a so-called fifth wheel can be arranged to control the movement of the platform trolley 10 to facilitate for a user.

With reference to the 2 , 3 and 4th is an exemplary embodiment of a total with 40 illustrated drive unit.

2 illustrates that the platform truck 10 on an underground 28 Is arranged rollable. In the exemplary embodiment, is marked with 30th designated arrow a first direction of travel. One with 32 labeled arrow indicates a second direction of travel. The first direction is exemplary 30th one direction for forward travel. The second direction is exemplary 32 one direction for reversing. This is not to be understood as restrictive.

The drive unit 40 is conventional and has some of the disadvantages described above. Nevertheless, reference is made to the following description of the drive unit 40 relation taken to explain aspects of the present disclosure based thereon. If below in connection with the 5 until 17th Distinguishing features are not explicitly discussed, it can therefore be assumed that the design elements and functions of the 2 until 4th illustrated drive unit 40 can also be used there.

The drive unit 40 includes a base 42 that connects to the platform 12th of the platform trolley 10 provides. At the base 42 may it be the platform 12th act yourself. However, the drive unit is also conceivable 40 with integrated base 42 to provide and the base 42 to the platform 12th to couple.

In the exemplary embodiment, there is at least one bearing piece 44 with the base 42 connected, in particular firmly connected. The drive unit 40 further comprises a drive wheel 46 . Between the bearing piece 44 and the drive wheel 46 a wheel carrier stretches in the form of a swing arm 52 . The swing arm 52 is pivotable on the bearing piece 44 stored. The drive wheel 46 is on the swing arm 52 stored. Furthermore, the drive unit 40 a biasing element 54 on, which is in the embodiment between the base 42 and the swingarm 52 extends. The prestressing element is an example 54 around a compression spring that supports the rocker arm 52 and consequently the drive wheel 46 against the ground 28 presses. This results in a favorable frictional connection between the drive wheel 46 and the underground 28 causing the drive wheel to spin 46 prevents or reduces the risk of spinning.

In exemplary configurations, the drive wheel is 46 closer to the fixed castors 20th , 22nd than with the steerable swivel castors 16 , 18th arranged. It is conceivable the drive wheel 46 close to that by the fixed castors 20th , 22nd formed axis 24 to be arranged, or even in alignment with the axis 24 , at least in exemplary embodiments. In this way the platform truck 10 still good on the swivel castors 16 , 18th being controlled.

In principle, it is also conceivable to use the platform truck 10 to be provided with four swivel castors, for example the four corners of the platform 12th are assigned, at least in exemplary configurations. This can increase maneuverability at the expense of straight-line stability. With such a design, the drive unit can be useful 40 with the drive wheel 46 centrally between the four rollers or wheels of the platform 12th to arrange.

In the exemplary embodiment, the drive unit comprises 40 a drive module 58 . The drive module 58 is in 2 only indicated schematically. The drive module 58 includes at least one motor 60 to drive the drive wheel 46 . In the exemplary embodiment is the motor 60 in the drive wheel 46 arranged. The motor 60 includes a stator 62 , the example of an axis 48 of the drive wheel 46 assigned.

The drive module 58 In the exemplary embodiment, it also includes an energy store 64 and a controller 66 which are only indicated schematically. The energy storage 64 includes, for example, a battery or an accumulator. The control 66 includes, for example, sensors, actuators, switches, operating elements, interfaces and the like.

To drive the drive wheel 46 generated by the engine 60 a drive torque. As a result, a counter-torque arises that is via a torque support 70 in the swing arm 52 is initiated. In other words, is the drive wheel 46 or its stator 62 via the moment support 70 non-rotating with the swing arm 52 tied together. A moving part (rotor) of the motor 60 or the drive wheel 46 is of course relative to the stator 62 and consequently relative to the rocker arm 52 rotatable.

With reference to the 3 and 4th become two conceivable operating states of the drive unit 40 illustrated. 3 illustrates a journey in the first direction 30th . 4th illustrates travel in the second direction 32 .

The feather 54 creates a preload force 74 who have favourited the swingarm 52 Direction underground 28 presses. Any weight forces from the rocker also act 52 and drive wheel 46 down towards the ground 28 .

A pressing force follows 76 who have favourited the drive wheel 46 against the ground 28 presses. In this way, the drive torque acting during the movement can 80 on the ground 28 be transmitted. Ultimately, there will be a thrust 84 that generates the drive unit 40 and a platform truck provided with it 10 in 3 in the first direction 30th emotional.

So that the drive torque 80 can act, a counter-torque must be directed in the opposite direction 88 via the moment support 70 be caught. The counter-moment 88 is about the moment support 70 in the swing arm 52 initiated. With the in 3 illustrated direction of travel 30th to an increase in the contact pressure 76 because the resulting force is the swing arm 52 additionally downwards towards the ground 28 presses.

4th however, illustrates the movement in the second direction of travel 32 . The drive torque acts to generate this movement 80 opposite to in 3 illustrated direction of the drive wheel 80 . A thrust results 84 that with the second direction of travel 32 is rectified. Consequently, this is also about the moment support 70 captured counter-torque 88 oriented in opposite directions.

I. E. however, that in the embodiment according to 4th in the second direction of travel 32 the counter moment 88 ultimately leads to a force component that affects the rocker 52 up, away from the ground 28 urges. In extreme cases, this can go so far that the direction of the resulting contact pressure changes 76 reverses. As a result, the drive wheel could turn 46 from the underground 28 lift up. At least the (actually downward) contact pressure is 76 when moving in the second direction of travel 32 reduced. As a result, the tendency to slip increases. The drive wheel 46 tends to go crazy.

It is now conceivable, the biasing element 54 to be dimensioned in such a way that there is a sufficiently large pre-tensioning force 74 results, which ensures that the contact pressure 76 is always directed downwards and does not fall below a certain amount. In such a case, however, it could, for example, be in the first direction of travel 30th according to 3 such a large downward pressure force 76 on the drive wheel reveal that surrounding rollers / wheels of the platform 12th can simply be raised. This operating state should also be avoided.

With reference to the 5 until 17th various exemplary embodiments of drive units are illustrated below, which are better than those in FIGS 2 until 4th The embodiment shown is suitable for movement in two directions of travel (forwards and backwards).

the 5 until 7th illustrate an embodiment of a total with 140 designated drive unit.

The drive unit 140 is designed to provide a platform (cf. 1 ) in a first direction of travel 130 and a second direction of travel 132 to move or to support the drive movement.

The drive unit 140 includes a base 142 who have favourited a stock item 144 wearing. There is also a drive wheel 146 intended. The drive wheel 146 can be swiveled on a wheel carrier 150 arranged. In the embodiment according to 5 until 7th is the wheel carrier 150 as a swing arm 152 designed. There is also a biasing element 154 to generate a pre-tensioning force 174 on the swing arm 152 intended. The pretensioning force preferably bears 174 to increase a contact force 176 on the drive wheel 146 at.

The drive unit 140 further comprises a motor 160 , which in the exemplary embodiment at least partially in the drive wheel 146 is integrated. The motor 160 includes a stator 162 . The stator 162 is fixed to one axis 148 tied together. In the exemplary embodiment, the stator 162 and the axis 148 together via a moment support 170 non-rotatably with a support element 190 coupled.

In the exemplary embodiment, the support element is 190 as a rocker arm 192 with a first arm 194 and a second arm 196 designed. Between the first arm 194 and the second arm 196 is the support element 190 articulated with the swing arm 152 of the wheel carrier 150 tied together. The drive wheel 146 is indirectly via the support element 190 swiveling on the wheel carrier 150 or its swing arm 152 arranged.

The swing arm 152 is articulated with the bearing piece at one end on the base side 144 tied together. The rocker arm 192 is at one end of the swing arm on the wheel side 152 articulately connected to this. The poor 194 , 196 define together with other elements a permitted relative pivoting between the rocker arm 192 and the swingarm 152 .

When moving the drive unit 140 in the first direction of travel 130 or the second direction of travel 132 a driving torque acts 180 that its direction of rotation changes depending on the direction of travel, compare 6th and 7th . The first direction of travel 130 is an example of a forward drive. The second direction of travel 132 is an example of driving backwards.

As already explained above, a corresponding counter-torque must be applied 188 through the moment support 170 be supported or caught. The moment support 170 directs the counter-torque 188 into the support element 190 . The support element 190 however, is to a limited extent relative to the rocker arm 152 pivotable. This results in the movement according to 7th in the first direction of travel 130 and when moving according to 6th in the second direction of travel 132 to different operating states.

In 6th is the movement in the second direction of travel 132 indicated. For reasons of illustration, the 4th referenced. When driving in the second direction 132 results from the drive torque 180 a counter-moment 188 that in 6th counterclockwise on that as a rocker arm 192 designed support element 190 acts. Hence that too Support element 190 Moved counterclockwise. However, the wheel carrier has 150 a stop for this movement. To this end, it extends between the base 142 or the bearing piece 144 and the second arm 196 of the rocker arm 192 a push rod 200 . The push rod 200 is articulated with the base 142 and the rocker arm 192 tied together. In addition, the push rod allows 200 a pushing motion.

In the embodiment according to 5 until 7th includes the push rod 200 a cylinder 202 in which a flask 204 can immerse. In the exemplary embodiment, the cylinder is 202 the bearing piece 144 and the piston 204 the rocker arm 192 assigned. Define the cylinder together 202 and the piston 204 a second stop that goes through the elements 214 , 216 is formed. In the exemplary embodiment, it is the element 214 for example a nut on one face 216 of the cylinder 202 can come to the plant. This is how the second stop defines 214 , 216 a maximum thrust movement between the cylinder 202 and the piston 204 and finally the distance between their crosspoints. This defines the second stop 214 , 216 also a maximum pivoting of the support element 190 relative to the swing arm 192 when the drive unit 140 is moved in the second direction of travel.

In the embodiment according to 5 until 7th are different mounting options 226 for the linkage on the base side and various fastening options 228 for the linkage of the push rod on the wheel side 200 intended. In this way, effective lever ratios and force ratios can be adapted, at least in exemplary configurations.

In 7th is based on a reduced representation, the movement in the first direction of travel 130 indicated. For reasons of illustration, the 3 referenced. When moving in the first direction of travel 130 results from the drive torque 180 an oppositely oriented counter-moment 188 , this in 7th is oriented clockwise. As a result, the support member rotates 190 also clockwise. The elements of the second stop are in this operating state 214 , 216 not to each other.

Instead, form the support element 190 , especially the first arm 194 of the rocker arm 192 , and a counter element on the rocker arm 152 (such as a protruding bolt or screw) a first stop 210 , 212 assigned to the first direction of travel. The drive unit behaves in this operating state 140 similar to the drive unit 40 in 3 . In other words, the drive torque takes care of it 180 ultimately for an increase in the effective contact pressure 176 .

In contrast, the drive unit behaves 140 in the in 6th illustrated operating state in the second direction of travel 132 different from the drive unit 40 in 4th . The elements that make up the first stop 210 , 212 are spaced from each other. Instead is the piston 204 in the cylinder 202 immersed, the elements 214 , 216 come to the plant to each other.

The wheel carrier acts in this operating state 150 overall like a four-link chain, roughly like a double swing arm. The counter-moment 188 is favorably supported and diverted, so that the unfavorable operating state according to 4th is avoidable. In exemplary embodiments, it is the wheel carrier 150 comprehensive coupling mechanism designed so that the resulting contact pressure is also applied when moving in the second direction of travel 176 by the applied drive torque 180 elevated. However, configurations are also conceivable in which there is indeed a reduction in the resulting contact pressure 176 comes, but not to the same extent as with the drive unit 40 according to 4th .

The 5 and 6th can be seen when viewed together that the pretensioning element 154 between a first end 220 and a second end 222 extends. The second ending 222 is the base 142 assigned. The first ending 220 is with the swing arm 152 coupled. In the exemplary embodiment, the biasing element is 154 designed as a tension spring. Consequently, the swing arm 152 by the biasing element 154 as shown in 6th be biased clockwise. This increases the contact pressure 176 of the drive wheel 146 .

the 8th and 9 illustrate another embodiment of a drive unit 240 . The design of the drive unit 240 is based on principles similar to the design of the drive unit 140 according to the 5 until 7th . Therefore, the following is primarily concerned with distinguishing features.

The drive unit 240 includes a base 242 who have favourited a stock item 244 wearing. In the manner already described, there is also a drive wheel 246 intended. The drive wheel 246 includes an axis 248 . A wheel carrier is used to support and guide the drive wheel 250 provided, the one swing arm 252 includes. There is also a biasing element 254 provided that a biasing force 274 brings up to the swing arm 252 and consequently the drive wheel 246 to push against the ground. So that the biasing element carries 254 to generate the contact pressure 276 at. The biasing element 254 extends between a first end 320 at the swing arm 252 and a second end 322 that is arranged on the frame side.

In the embodiments according to 5 until 9 is the biasing element 154 , 254 oriented essentially horizontally. This allows a compact and protected design.

The drive wheel 246 sits with its axis 248 on a support element 290 that acts as a rocker arm 292 is designed. The rocker arm 292 has a first arm 294 and a second arm 296 on. With the first arm 294 is the rocker arm 292 with the swing arm 252 coupled. In the embodiment according to 8th and 9 the coupling takes place at a joint 336 that from the axis 248 is spaced.

With the second arm on the opposite side 296 is the rocker arm 292 with a push rod 300 coupled. The push rod 300 includes a flat bar 302 who has an elongated hole or eye 304 having. The push rod 300 forms together with the rocker arm 292 a sliding joint 338 . An example is one on the rocker arm 292 fastened bolt in the eye 304 mounted longitudinally displaceable.

Between the first arm 294 and the swingarm 252 form elements 310 , 312 a first stop at a base end of the eye 304 . Between the second arm 296 and the push rod 300 form elements 314 , 316 a second stop. The rocker arm 292 can be relative to the wheel carrier 250 between the first stop 310 , 312 and the second stop 314 , 316 be pivoted.

In this respect, the wheel carrier is also 250 similar to the wheel carrier 150 designed as a coupling mechanism. The first direction of travel 230 and the second direction of travel 232 are indicated by directional arrows in the 8th and 9 shown. Curved double arrows 280 and 288 illustrate the drive torque 280 and the opposing counter-torque 288 for the support. The drive wheel is supported in the manner already described above 246 via a moment support 270 on the support element 290 from, making this relative to the swing arm 252 or to the push rod 300 is pivoted.

In the second operating state, in the second direction of travel 232 , the wheel carrier acts 250 similar to a four-link chain if the rocker arm 292 at the in 9 Orientation shown is pivoted counterclockwise and the elements 314 , 316 come to one another to the plant.

In the first operating state, in the first direction of travel 230 , is the rocker arm 292 at the in 9 Orientation shown pivoted clockwise until the elements 310 , 312 rest against each other and act as a stop. The rocker arm is in this operating state 252 at the applied moment firmly with the rocker arm 292 tied together.

In the embodiment according to 9 are different mounting options 328 , 334 on the support element 290 indicated. The reference number 328 denotes different pick-up positions for the element 314 . The reference number 334 denotes different recording positions for the joint 336 . In this way, desired climatic conditions can be created.

the 10 until 12th illustrate another embodiment of a total with 340 designated drive unit. The drive unit 340 includes a base 342 , on which at least two bearing pieces 344 , 356 are arranged. The drive unit 340 is to move in a first direction of travel 330 and a second, opposite direction of travel 332 educated. The at least two bearings 344 , 356 are offset from each other in the direction of travel at the base 342 arranged.

The drive unit 340 further comprises a drive wheel 346 with one axis 348 . For holding and guiding the drive wheel 346 is a wheel carrier 350 intended. In the embodiment according to 10 until 12th is the wheel carrier 350 designed as a parallel guide. The drive unit also includes 340 a biasing element 354 that in the exemplary embodiment adjacent to the base 342 is arranged. In the case of the prestressing element 354 it is, for example, a tension spring that has a pretensioning force 374 on the wheel carrier 350 generated in a contact pressure 376 comes in.

The drive wheel 346 is about a moment support 370 non-rotatably on a support element 390 recorded. It goes without saying that the non-rotatable receptacle is in particular a stator in the drive wheel 346 integrated motor on the support element 390 specifies. Other components of the drive wheel 346 are of course rotatable. The support element 390 is in the embodiment as a rocker arm or rocker arm 392 designed. The support element 390 is designed, for example, V-shaped or U-shaped. In the center of the support element 390 with the moment support 370 is the axis 348 arranged. The support element 390 has a first arm 394 and a second arm 396 on.

The wheel carrier 350 comprises at least one first rocker 400 that are on stock 344 is articulated. There is also a second rocker arm 402 provided on the bearing piece 356 is articulated. The first swing arm 400 and the second swing arm 402 are in the direction of travel 330 , 332 spaced from each other. The drive wheel 346 is between the first swing arm 400 and the second swing arm 402 arranged.

In the exemplary embodiment, the two rockers are 400 , 402 each designed approximately L-shaped. The two wings 400 , 402 are coupled to one another for pivoting movement in the same direction. Between the two wings 400 , 402 extends a backdrop 404 . The scenery guide 404 is articulated with the first swing arm 400 and the second swing arm 402 coupled. In particular, the link guide 404 with a first arm of each of the two wings 400 , 402 coupled. In the exemplary embodiment, the two rockers are 400 , 402 also via a coupling piece 418 connected with each other. The coupling piece 418 is articulated with the first swing arm 400 and the second swing arm 402 coupled. In particular, the coupling piece is 418 with a second arm of each of the two wings 400 , 402 coupled.

Overall, this results from the two rockers 400 , 402 , the scenery tour 404 and the coupling piece 418 a parallel guide that is part of the wheel carrier 350 is. The scenery guide 404 includes a first backdrop 406 that the first arm 394 of the rocker arm 392 assigned. Furthermore, the link guide includes 404 a second backdrop 408 that the second arm 396 of the rocker arm 392 assigned.

On the first arm 394 is a guide element 410 arranged, for example in the form of a guide pin. On the second arm 396 is a guide element 414 arranged, for example in the form of a guide pin. The two guide elements 410 , 414 each define stops of the rocker arm 392 at its pivoting or tilting movement, compare one with 424 designated curved double arrow in 12th .

For the first arm 394 forms the guide element 410 together with the element 412 at the end of the backdrop 406 a first stop. For the second arm 396 forms the guide element 414 together with the element 416 at the end of the backdrop 408 a second stop. In the 10 until 12th is an example of the movement in the second direction of travel 332 illustrated. Accordingly, this lies as a rocker arm 392 designed support element 390 at the second stop, the one through the elements 414 , 416 is formed. In this operating state, the elements make contact 410 , 412 not each other.

In the opposite first direction of travel 330 would get the elements 410 , 412 contact to form the first stop. On the other hand would be the elements 414 , 416 spaced from each other.

In the exemplary embodiment, the biasing element is designed as a spring 354 the coupling piece 418 arranged adjacent. The coupling piece 418 extends between the two wings 400 , 402 . In contrast, the prestressing element extends 354 between a first end 420 at the first swing arm 400 and a base second end 422 . About the coupling piece 418 becomes the preload force 374 in both wings 400 , 402 initiated.

In 11 is also with 426 a return spring indicated, for example when the drive unit is at a standstill 340 for a defined position of the support element 390 and consequently the drive wheel 346 in relation to the wheel carrier 350 cares. Unless there is a high tilting moment or pivoting moment on the support element 390 acts, a neutral position of the support element would result 190 , in which both guide elements 410 , 414 that through the elements 412 , 416 formed upper end of the scenes 406 , 408 to contact.

The scenes 406 , 408 are designed in such a way that when one of the two guide elements is in contact 410 , 412 on a stop element at the upper end of the respective gate 406 , 408 , the other setting a circular path for the opposite guide element 410 , 412 forms. In this way, the desired tilting movement or pivoting movement can be used as a rocker arm 392 designed support element 390 between the two attacks.

In 11 is with 380 when moving in the second direction of travel 332 applied drive torque indicated. Furthermore, the resulting counter torque is 388 indicated which one about the moment support 370 into the support element 390 and finally in the wheel carrier 350 is initiated. In the exemplary embodiment, the counter-torque carries 388 to increase the contact pressure 376 at. The scenery guide 404 with the two symmetrically designed backdrops 406 , 408 and the symmetrical design of the support element 390 lead to a similar behavior with a positive contribution from the counter-torque 388 to contact pressure 376 when the drive unit is in the opposite first direction of travel 330 is operated.

By tilting the support element 390 with the first arm 394 and the second arm 396 first becomes the axis 348 of the drive wheel 346 pushed down towards the ground. However, this compensatory movement is determined by the given height of the platform trolley 10 (compare 1 , the platform 12th stands on roles 16 , 18th , 20th , 22nd ) limited or entirely above the subsurface prevented, provided the mass of the platform trailer 10 is high enough. Instead, the scenery guide 404 of the wheel carrier 350 slightly raised. This increases the swing stroke of the first rocker 400 and the second swing arm 402 . As a result, it increases by the biasing member 354 applied pretensioning force 374 . As a result, the effective contact pressure also increases 376 .

the 13th and 14th illustrate another embodiment of a drive unit 440 which are based on similar design principles as the drive unit 340 according to the 10 until 12th is designed.

The drive unit 440 is designed to provide a favorable contact pressure for a drive wheel 446 available, regardless of a current direction of travel, compare the two arrows 430 , 432 in 13th .

The drive unit 440 includes a base 442 , on which two or more bearing pieces 444 are arranged. The drive unit also includes 440 a basically previously described drive wheel 446 , the one axis 448 includes. The drive wheel 446 is indirectly on a wheel carrier 450 recorded. The wheel carrier 450 is vertically displaceable on the bearing pieces in the exemplary embodiment 444 recorded. The wheel carrier 450 includes a lifting beam 452 . In the embodiment according to 13th and 14th includes the wheel carrier 450 So no rocker, but an element that can be moved in a translatory manner, the lifting beam 452 . The stock pieces 444 serve as a lifting guide for the lifting beam 452 .

Between the lifting beam 452 and the base 442 at least one biasing element extends 454 that a preload force 474 generated. The preload 474 urges the lifting beam 452 away from the base 442 . This way, the drive wheel becomes 446 pressed down onto the substrate.

The drive wheel is supported in the manner already described above 446 via a moment support 470 on a support element 490 away. The support element 490 is the support element 390 according to the 10 until 12th similarly designed. The support element 490 is in the embodiment as a V-shaped rocker arm 492 designed. The rocker arm 492 includes a first arm 494 and a second arm 496 . The drive wheel 446 supports itself with its axis 448 and the moment support 470 in a center of the support element 490 away.

The coupling of the drive wheel 446 with the lifting beam 452 of the wheel carrier 450 takes place in the exemplary embodiment indirectly via a link guide 504 on which the support element 490 is pivotably recorded. The scenery guide 504 includes a first backdrop 506 and a second backdrop 508 . The first backdrop 506 is the first arm 494 assigned. The second backdrop 508 is the second arm 496 assigned. The first arm 494 carries a guide element 510 that in the backdrop 506 is led. The second arm 496 carries a guide element 514 that in the backdrop 508 is led. The guiding element 510 forms together with an element 512 at the top of the backdrop 506 a first stop. The guiding element 514 forms together with an element 516 at the top of the backdrop 508 a second stop.

In 14th illustrates a curved double arrow 524 the pivoting or tilting movement of the rocker arm 492 designed support element 490 . In the orientation according to 14th comes the support element 490 with the guide element 510 to the stop at the stop 512 . Consequently, the support element lies 490 at the first stop. In the exemplary embodiment, this corresponds to the movement in the first direction of travel 430 . If, however, the support element comes 490 according to the dashed representation in 14th with the guide element 514 to the stop at the stop 516 , the support element lies 490 at the second stop, that of the second direction of travel 432 is assigned, compare the dashed representation in 14th . In both cases there are favorable effects on the effective contact pressure, compare the explanations in connection with the 11 and 12th .

Furthermore, there is at least one return spring 526 provided that the support element 490 and thus the drive wheel 446 in a neutral position relative to the link guide 504 urges. This is done, for example, when the drive unit 440 is not moved.

By tilting the support element 490 with the first arm 494 and the second arm 496 first becomes the axis 448 of the drive wheel 446 pushed down towards the ground. However, this compensatory movement is determined by the given height of the platform trolley 10 (compare 1 , the platform 12th stands on roles 16 , 18th , 20th , 22nd ) above the ground limited or completely prevented, provided that the mass of the platform truck 10 is high enough. Instead, the lifting beam is used 452 of the wheel carrier 450 slightly raised. This increases the vertical stroke on the stroke guide 444 . As a result, the one or more prestressing elements increases 454 applied pretensioning force 474 . As a result, the effective contact pressure also increases.

the 15th until 17th illustrate a further exemplary embodiment of a drive unit designated as a whole by 540. the Drive unit 540 has a base 542 on, at least two bearing pieces in the exemplary embodiment 544 , 556 are arranged. The drive unit 540 further comprises a drive wheel 546 as already described above. The drive wheel 546 can be driven by a motor to drive the drive unit 540 if necessary in a first direction of travel 530 and a second direction of travel 532 to operate.

The drive wheel 546 is about its axis 548 indirectly on a wheel carrier 550 recorded. The wheel carrier 550 comprises at least one first rocker in the exemplary embodiment 552 and a second swing arm 602 . The first swing arm 552 and the second swing arm 602 are at each other in the direction of travel 530 , 532 spaced bearing pieces 544 , 556 articulated. The two wings 552 , 602 are common and opposite to the base 542 pivotable.

Similar to the previously described embodiments in connection with the 5 until 14th is the drive wheel 546 on a support element 590 recorded non-rotatably. The moment is supported by the element 570 . The moment support 570 makes sure the drive wheel 546 and the support element 590 are pivotable together. In the exemplary embodiment, the axis defines 548 of the drive wheel 546 also the (current) pivot axis of the support element 590 .

The support element 590 is as a rocker arm 592 with a first arm 594 and a second arm 596 designed. In the exemplary embodiment, the two arms are 594 , 596 turned away from each other. The support element 590 is designed like a grand piano. On the first arm 594 is a stop surface 610 educated. On the second arm 596 is a second stop surface 614 educated.

That as a rocker arm 592 designed support element 590 is relative to first swing arm 552 and to the second swing arm 602 pivotable. In particular 16 it can be seen that the axis 548 of the drive wheel 546 through an elongated hole 604 the first swing arm 552 and an elongated hole 606 the second swing arm 602 in the direction of the support element 590 extends. On the support element 590 is the axis 548 via the moment support 570 non-rotatably attached.

The two elongated holes 604 , 606 equal the changing center distance between the axis 548 and swivel axes 624 , 626 ( 16 ) of the two wings 552 , 602 during the pivoting movement of the support element 590 the end. The swivel axes 624 , 626 each define a joint. It is also conceivable only with one of the two wings 552 , 602 to provide an elongated hole. In the case of the 15th until 17th The illustrated embodiment ideally results in a substantially vertical movement of the drive wheel 546 when the two wings 552 , 602 be pivoted relative to each other, in opposite directions and with the same amount.

On the first swing arm 552 is a stop 612 arranged. On the second swing arm 602 is a stop 616 arranged. The two attacks 612 , 616 are exemplarily designed as screws, bolts and the like. The one on the support element 590 trained attacks 610 , 614 can depending on a current pivot orientation of the support element 590 at one of the attacks 612 , 616 come to the plant.

17th illustrates a state of the drive unit 540 when moving in the first direction of travel 530 . In the first direction of travel 530 a driving torque acts 580 , which is a counter-moment 588 conditionally, that about the torque arm 570 into the support element 590 is initiated. In the in 17th Orientation shown, this leads to a pivoting movement of the rocker arm 592 formed support element 590 clockwise. The support element 590 however, it can only be swiveled within defined limits. Once the elements 610 , 612 contact each other, lies the first arm 594 at the first stop.

When the drive unit moves 540 in the second direction of travel 532 would be the support element 590 accordingly pivot counterclockwise until the opposite second arm 596 am through the elements 614 , 616 formed second stop comes to the plant.

The drive unit 540 and their wheel carriers 550 are designed so that both in the first direction of travel 530 as well as in the second direction of travel 532 the effective moment 580 and the resulting counter torque 588 to an increase in the contact pressure 576 contributes.

17th further illustrates that the biasing element 554 between a first end 620 and a second end 622 extends. In the exemplary embodiment is the first end 620 the first swing arm 552 assigned. The second ending 622 is the second swing arm 602 assigned. Hence the biasing element 554 in the exemplary embodiment not directly at the base 542 stored. The biasing element 554 is exemplarily designed as a tension spring that supports the two rockers 552 , 602 braced against each other. The biasing element 554 acts in such a way that the first rocker 552 clockwise and the second rocker 602 is biased counterclockwise. This also results in a central neutral position for the support element 590 .

In an exemplary embodiment, the support element makes contact 590 in the neutral position both the first stop 610 , 612 as well as the second stop 614 , 616 if a correspondingly high load (e.g. weight on the platform truck 10 ) is present. The drive unit is an example 540 designed such that in a compressed position of the wheel carrier 550 In the neutral position there is still a clearance of at least 1.0 mm between the elements 610 , 612 of the first attack as well as the elements 614 , 616 of the second attack is given. For this purpose is the drive unit 540 with the wheel carrier 550 in a suitable manner to a given height of the platform trolley 12th (compare 1 ) customized.

The ones in the 5 until 17th illustrate configurations of the drive units 140 , 240 , 340 , 440 , 540 are designed essentially mirror-symmetrically with respect to a longitudinal center plane that is parallel to the direction of travel. In exemplary embodiments, the longitudinal center plane is a central plane in the respective drive wheel that is perpendicular to its axis. The symmetrical structure reduces lateral forces and bending moments. The respective drive wheel can be supported centrally. During the pivoting movement of the drive wheels and the support elements in response to the applied moments, lateral forces can be minimized or even avoided with components that are oriented parallel to the extension of the respective axis. The symmetrical design with respect to the longitudinal center plane is therefore advantageous. However, this does not rule out that non-symmetrical designs are also conceivable. This also includes a one-sided mounting and support of the drive wheels. In that regard, those in the 5 until 17th Illustrated embodiments are not to be understood as restrictive.

It goes without saying that terms such as first element, second element and the like are used primarily for reasons of distinctness and for illustration. In other words, no ranking or weighting can be derived from terms such as first element and second element. It is conceivable that specific exemplary embodiments only have second elements, whereas corresponding first elements are dispensed with in these exemplary embodiments. This is not to be understood as restrictive.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• EP 1003663 B1 [0002]
• EP 3202636 A1 [0003]

Claims (25)

Drive unit with a drive wheel (146, 246, 346, 446, 546) that can be driven by an electric motor, in particular a fifth wheel, for a rollable platform (12), the drive unit having the following: - a base (142, 242, 342, 442, 542) , which can be coupled to a rollable platform (12), - a drive wheel (146, 246, 346, 446, 546) which can be driven by an electric motor and which runs in a first direction of travel (130, 230, 330, 430, 530) and a second, opposite direction of travel (132, 232, 332, 432, 532) is drivable, - a pretensioning element (154, 254, 354, 454, 554) to increase a pressing force (176, 276, 376, 476, 576) on the drive wheel (146, 246 , 346, 446, 546), - at least one wheel carrier (150, 250, 350, 450, 550) between the base (142, 242, 342, 442, 542) and the drive wheel (146, 246, 346, 446 , 546) is arranged, wherein the wheel carrier (150, 250, 350, 450, 550) against a force exerted by the biasing element (154, 254, 354, 454, 554) relative to the base (142, 242, 342, 442, 542 ) is movable, and wherein in the first direction of travel (130, 230, 330, 430, 530) the drive torque applied to the drive wheel (146, 246, 346, 446, 546) increases the contact pressure (176, 276, 376, 476, 576 ), characterized by - a torque support (170, 270, 370, 470, 570) with at least one support element (190, 290, 390, 490, 590) which, when the drive unit is in operation, acts as a reaction to the drive torque on the drive wheel (146 , 246, 346, 446, 546) acting counter-torque (188, 288, 388, 588) is supported in such a way that the counter-torque (188, 288, 388, 588) when driving in the second direction of travel (132, 232, 332, 432, 532) contributes to maintaining the contact pressure (176, 276, 376, 476, 576). Drive unit after Claim 1 , the torque support (170, 270, 370, 470, 570) being designed in such a way that the counter-torque (188, 288, 388, 588) generated during operation of the drive unit both in the first direction of travel (130, 230, 330, 430, 530) as well as in the second direction of travel (132, 232, 332, 432, 532) a force component is generated on the wheel carrier (150, 250, 350, 450, 550) which is the same as that generated by the pretensioning element (154, 254 , 354, 454, 554) contributes to increasing the contact pressure (176, 276, 376, 476, 576). Drive unit after Claim 1 or 2 , wherein the torque support (170, 270, 370, 470, 570) comprises at least one support element (190, 290, 390, 490, 590) coupled to the drive wheel (146, 246, 346, 446, 546), which relative to the wheel carrier (150, 250, 350, 450, 550) is pivotable. Drive unit after Claim 3 , wherein the at least one support element (190, 290, 390, 490, 590) between a first stop (212, 312, 412, 512, 612) and a second stop (216, 316, 416, 516, 616) relative to the wheel carrier (150, 250, 350, 450, 550) is pivotable. Drive unit after Claim 4 , wherein the at least one support element (190, 290, 390, 490, 590) in the first direction of travel (130, 230, 330, 430, 530) on the first stop (212, 312, 412, 512, 612) and in the second direction of travel (132, 232, 332, 432, 532) is supported on the second stop (216, 316, 416, 516, 616). Drive unit after Claim 4 or 5 , wherein the pivoting movement of the at least one support element (190, 290, 390, 490, 590) during the movement between the first stop (212, 312, 412, 512, 612) and the second stop (216, 316, 416, 516, 616) changed a lever for introducing the counter-torque (188, 288, 388, 588) in the wheel carrier (150, 250, 350, 450, 550). Drive unit according to one of the Claims 1 until 6th , wherein the at least one support element (190, 290, 390, 490, 590) as a rocker arm (190, 290, 390, 490, 590) with two arms (194, 294, 394, 494, 594; 196, 296, 396, 496, 596), each of which is assigned to a stop (212, 312, 412, 512, 612; 216, 316, 416, 516, 616). Drive unit after Claim 7 , wherein at least one arm (194, 294, 394, 494, 594; 196, 296, 396, 496, 596) of the rocker arm (190, 290, 390, 490, 590) allows an adjustment of the effective lever length. Drive unit after Claim 7 or 8th , wherein at least one arm (196, 296) of the rocker arm (192, 292) cooperates with a push rod (200, 300) pivotably mounted on the base (142, 242, 342, 442, 542), the arm (196, 296 ) of the rocker arm (192, 292) in a stop position directly or indirectly comes into contact with a stop (216, 316) on the push rod (200, 300), and the arm (196, 296) of the rocker arm (192, 292) is removed in the opposite stop position from the stop (216, 316) of the push rod (200, 300). Drive unit after Claim 9 , wherein the push rod (200, 300) comprises a piston-cylinder guide or a translational link guide, which in the second pivot position provide the second stop (216, 316) for the support element (190, 290, 390, 490, 590). Drive unit after Claim 9 or 10 , wherein the base (142, 242), the at least one Wheel carrier (150, 250), the at least one support element (190, 290) and the push rod (200, 300) together form a four-bar chain when the at least one support element (190, 290) rests against the second stop (216, 316). Drive unit according to one of the Claims 1 until 11 , wherein the wheel carrier (150, 250, 350, 450, 550) comprises at least one rocker arm which is pivotable against a prestressing force applied by the at least one prestressing element (154, 254, 354, 454, 554) on the base (142, 242, 342, 442, 542), and wherein the at least one rocker (152, 252, 400, 402, 552, 602) has a pivot axis which is parallel to an axis of rotation (148, 248, 348, 548) of the drive wheel (146 , 246, 346, 546). Drive unit after Claim 12 , wherein the at least one rocker (152, 252, 552, 602) provides a first stop (212, 312, 612) for the support element (190, 290, 390, 490, 590), in particular one in the first direction of travel (130, 230, 330, 430, 530) effective stop (212, 312, 612). Drive unit after Claim 12 or 13th , comprising at least one first rocker (400, 552) and at least one second rocker (402, 602) offset with respect to the first rocker (400, 552), the at least one first rocker (400, 552) and the at least one second rocker ( 402, 602) are each mounted on the base (142, 242, 342, 442, 542), and the pivot axes of the first rocker (400, 552), the second rocker (402, 602) and the at least one support element (390, 590) are parallel to and spaced from each other. Drive unit after Claim 14 , wherein the first rocker (552) has a first stop (612) for the support element (590) for the first direction of travel (530) and the second rocker (602) has a second stop (616) for the support element (590) for the second direction of travel (532) provides. Drive unit after Claim 14 or 15th , wherein the first rocker (552) and the second rocker (602) can be pivoted together, the first rocker (552) and the second rocker (602) being pivotable in opposite directions, and preferably at least the first rocker (552) or the second rocker (602) has a longitudinal guide (604, 606) to compensate for changes in the center distance. Drive unit after Claim 13 , wherein the first rocker (400) and the second rocker (402) are positively coupled via a coupling piece (418) in order to move in the same direction, preferably also in the same amount, relative to the base (342), and the first rocker (400) and the second rocker (402) together hold a link guide (404) which serves as a guide for the support element (390). Drive unit according to one of the Claims 1 until 10 wherein the wheel carrier (450) comprises at least one lifting carrier (452) which is movable along a lifting guide (444) against a prestressing force (484) applied by the at least one prestressing element (454) relative to the base (442). Drive unit after Claim 18 , wherein the wheel carrier (450) holds a link guide (504) which serves as a guide for the support element (490). Drive unit after Claim 17 or 19th , the link guide (404, 504) having a first link (406, 506) for a first arm (494, 594) of the support element (390, 490) and a second link (408, 508) for a second arm (494, 496 ) of the support element (390, 490), and wherein the first link (406, 506) and the first arm (494, 594) have a first stop (412, 512) for the first direction of travel (330, 430) and the second link (408, 508) and the second arm (494, 496) form a second stop (414, 514) for the second direction of travel (332, 432). Drive unit after Claim 20 , wherein the first link (406, 506) and the second link (408, 508) allow a pivoting movement of the support element (390, 490) between the first stop (408, 508) and the second stop (414, 514). Drive unit after Claim 20 or 21 , wherein the support element (190, 290, 390, 490, 590) in the link guide (404, 504) is biased towards a neutral position. Drive unit according to one of the Claims 1 until 22nd wherein the at least one biasing element (154, 254, 354, 454, 554) extends between the base (142, 242, 342, 442, 542) and the wheel carrier (150, 250, 350, 450, 550), and wherein a force generated by the at least one biasing element (154, 254, 354, 454, 554) tensions the base (142, 242, 342, 442, 542) and the wheel carrier (150, 250, 350, 450, 550) relative to one another. Platform trolley (10) with a rollable platform (12) for receiving a load, four or more rollers (16, 18, 20, 22), which are assigned to corners of the platform (12), and with a drive unit according to one of the preceding claims. Use of a drive unit according to one of the Claims 1 until 23 as a conversion kit for motorizing a rollable platform (12).

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