EP4279695A1 - Door drive - Google Patents

Abstract

The invention relates to a door drive (200) for a door, comprising a housing (210) with a hydraulic cylinder (212), a drive mechanism (218) which can be coupled to the door and is arranged in the hydraulic cylinder (212) and has a displaceable drive piston (220) and a closer spring (224) which acts on the drive piston (220) in the closing direction of the door, wherein on the side of the drive piston (220) opposite the closer spring (224) there is a pressure chamber (214) for applying a hydraulic fluid (102) to the drive piston (220). Opening direction of the door is formed, a hydraulic system (90), and a hydraulic pump (10) for conveying the hydraulic fluid (102) into the pressure chamber (214).

Description

The present invention relates to a door drive for a door, comprising a housing with a hydraulic cylinder, a drive mechanism which can be coupled to the door and is arranged in the hydraulic cylinder, with a displaceable drive piston and a closer spring which acts on the drive piston in the closing direction of the door, on the side opposite the closer spring of the drive piston, a pressure chamber is formed for applying a hydraulic fluid to the drive piston in the opening direction of the door, a hydraulic system, and a hydraulic pump for conveying the hydraulic fluid into the pressure chamber.

Mechanical door closers, especially with hydraulic damping, are generally known and are used worldwide. In these door closers, a closer spring is usually used as a mechanical energy storage device, which is pretensioned when the door is opened and ensures that the door closes securely after the door is released. However, such mechanical door closers can represent an obstacle for certain groups of people, for example disabled, old or young people, but also for example for autonomous vehicles, since, as described above, additional force must be used to pretension the closer spring.

Fully automatic door drives can solve this problem, but are complex to purchase, install, operate and maintain and are therefore expensive. Automatic door drives that have a hydraulic drive are also known. However, it has been found that hydraulic pumps for use in door drives must meet high requirements, for example with regard to the pressure to be achieved, the lowest possible leakage rate, a low installation space requirement and low operating noise. Conventional hydraulic pumps, such as gear pumps or vibration pumps, cannot fully meet these numerous requirements.

It is therefore the object of the present invention to at least partially eliminate the disadvantages of known door drives of the prior art described above. In particular, it is the object of the present invention to create a door drive with a hydraulic drive which has a low, preferably no, leakage rate as well as a compact and inexpensive design and can also provide sufficiently high pump pressures for door drives during operation with the lowest possible operating noise.

The above task is solved by the patent claims. In particular, the task is solved by a door drive with the features of independent claim 1. Further features and advantages of the door drive according to the invention result from the subclaims, the description and the drawings.

According to the invention, the object is achieved by a door drive for a door, comprising a housing with a hydraulic cylinder, a drive mechanism which can be coupled to the door and is arranged in the hydraulic cylinder, with a displaceable drive piston and a closer spring which acts on the drive piston in the closing direction of the door, whereby on the On the side of the drive piston opposite the closer spring, a pressure chamber is formed for applying a hydraulic fluid to the drive piston in the opening direction of the door, a hydraulic system, and a hydraulic pump for conveying the hydraulic fluid into the pressure chamber. The door drive according to the invention is characterized in that the hydraulic pump is a piston pump with an axially displaceable and rotationally fixed arrangement in a fluid space and against a wall of the Fluid space sealed pump piston is formed, which delimits a pump space connected to the pressure side of the hydraulic pump, wherein the hydraulic system has a first hydraulic connection that connects the pump space to the pressure space, wherein the hydraulic pump comprises an electric motor unit with a drive shaft and a drive section of the drive shaft via a Threaded connection is coupled to the pump piston in order to axially displace the pump piston in the fluid space and thereby carry out a stroke of the piston.

The door drive according to the invention is intended for use on a door, in particular in order to open it hydraulically and, on the other hand, to close it automatically, in particular automatically mechanically, after an opening process. The door drive according to the invention can be mounted on both the hinge side and opposite hinge side as well as in door leaf or head mounting. When the door is opened, regardless of whether it is a manual opening process or a hydraulically driven opening process, the drive piston inside the hydraulic cylinder of the housing of the door drive according to the invention is displaced against the force of the closer spring, whereby mechanical energy is transferred as potential energy in the Closing spring is stored. After the drive piston is released, this mechanical energy stored in the closer spring is released and the drive piston is moved back to its starting position. The result is that the door equipped with the door drive according to the invention closes.

In particular, the door drive according to the invention is provided as a hydraulically driven door drive. For this purpose, the door drive according to the invention in particular has a hydraulic pump for conveying the hydraulic fluid, which can convey hydraulic fluid into a pressure chamber via a first hydraulic connection of the hydraulic system of the door drive according to the invention. This pressure room is on the Closer spring arranged on the opposite side of the drive piston, so that an application of hydraulic fluid to the pressure chamber leads to a displacement of the drive piston against the force of the closer spring and thus, mediated by the drive mechanism, which drives, for example, a drive shaft and a lever linkage coupled to it in a drive-effective manner or a lever-slide rail unit , leading to the door opening.

According to the invention, the hydraulic pump of the door drive according to the invention is designed as a piston pump, in particular as a single-piston pump. The pump piston of the piston pump moves in a fluid space in which the pump piston is arranged to be axially displaceable and at the same time non-rotatable. Due to the rotation-proof arrangement, the pump piston is also automatically guided in the fluid space. By sealing against a wall of the fluid space, a pump space is delimited in the fluid space and, on the other hand, this seal can enable a low or even negligible leakage rate. The pump chamber delimited in the fluid chamber by the pump piston is connected to the pressure side of the hydraulic pump, whereby when the pump piston moves in the fluid chamber to reduce the volume of the pump chamber, the hydraulic fluid is conveyed from the fluid chamber via the first hydraulic connection, which connects the pressure side of the hydraulic pump to the pressure chamber Pump chamber takes place in the pressure chamber in front of the drive piston. Actuating the drive piston with the hydraulic fluid can thereby be provided particularly easily, which means that at the same time it is possible to move the drive piston by applying the hydraulic fluid against the force of the closer spring.

In particular, in the door drive according to the invention it is provided that the hydraulic pump has an electric motor unit as a drive, the drive shaft of which is coupled to the pump piston via a threaded connection. Such a threaded connection allows particularly high pressures are generated because the threaded connection can provide a high translation between the rotational speed of the drive shaft and the displacement speed of the pump piston in the fluid space.

At the same time, a threaded connection is a mechanically particularly simple drive-effective connection, since, for example, complex and maintenance-intensive swashplates or swashplates or connecting rods and/or lever linkages for moving the pump piston can be dispensed with. The installation space requirement of such a drive with a threaded connection is also reduced compared to such piston pumps. Furthermore, by dispensing with the aforementioned complex mechanical components, operating noise when operating the door drive according to the invention can be reduced.

In summary, by using a hydraulic pump that is designed as a piston pump and whose pump piston is moved via a threaded connection, particularly high pumping pressures can be achieved with simultaneously reduced operating noise compared to other hydraulic pump concepts. The power requirement of the piston pump according to the invention is also reduced compared to other hydraulic pump concepts. In addition, the design of the hydraulic pump of the door drive according to the invention is particularly compact, mechanically simple and therefore less maintenance-intensive, and enables particularly low leakage rates, which means that maintenance costs can be saved.

Furthermore, in the door drive according to the invention it can be provided that an axis of the threaded connection is arranged offset from a central axis of the pump piston in order to arrange the pump piston in a rotationally fixed manner in the pressure chamber. Due to an offset between the axis of the threaded connection and a central axis of the pump piston, the pump piston can be supported on the wall of the fluid space, which means that the pump piston rotates when it rotates Drive shaft is prevented. A rotationally fixed arrangement of the pump piston in the fluid space can thus be made particularly easy. In particular, in this embodiment of the door drive according to the invention, the pump piston and the fluid space can be cylindrical. Manufacturing these elements of the door drive according to the invention can thereby be simplified.

Alternatively or additionally, the door drive according to the invention can be characterized in that for the rotationally fixed arrangement of the pump piston in the fluid space, the pump piston is received in the fluid space in a form-fitting manner in the circumferential direction, in particular wherein the pump piston and the wall of the fluid space have a shape different from a circle and/or wherein a guide groove is provided on the pump piston and a corresponding guide pin is provided on the wall of the fluid space, or vice versa. In this embodiment, instead of or in addition to an axial offset of the threaded connection and the pump piston, a rotationally fixed arrangement of the pump piston is prevented by a positive connection between the pump piston and the fluid space in the circumferential direction. A rotation of the pump piston in the circumferential direction is prevented by the positive abutment of the pump piston on the fluid space. This can be achieved, for example, by using a shape of the pump piston and the wall of the fluid space that is different from a circle. This shape can, for example, be elliptical, polygonal or essentially circular with a linear section. A guide groove and a corresponding engaging guide pin, one of these elements being arranged on the wall of the fluid space and the other on the pump piston, also leads to the pump piston being supported on the wall of the fluid space and, as a result, to a rotationally fixed arrangement of the pump piston in the fluid space.

The door drive according to the invention can also be designed in such a way that the threaded connection is a trapezoidal thread, a saw thread, or a ball screw or a roller thread is formed. The types of threads listed above allow particularly high forces to be transmitted. This makes it possible to move the drive piston against closing springs with particularly high spring hardness. This makes it possible, in particular, for the closing spring installed in the door drive according to the invention to be shortened overall, as a result of which the installation space requirement for the door drive according to the invention is reduced.

Furthermore, in the door drive according to the invention it can be provided that for the threaded connection the drive section is designed as a threaded spindle with an external thread and the pump piston has a receiving area, preferably a receiving hole, for receiving the threaded spindle, the receiving area being designed at least in sections as a threaded nut with a corresponding internal thread is, wherein preferably the threaded nut is arranged on an end of the pump piston facing the motor unit. In this first possible implementation of the threaded connection, the drive shaft has an external thread and the pump piston has a corresponding internal thread. The receiving area of the pump piston is preferably dimensioned such that at an end position of the pump piston in the fluid space near the motor unit, the entire drive section designed as a threaded spindle is received in the receiving area of the pump piston. At the same time, it is preferred that the drive section designed as a threaded spindle is designed to be so long that the threaded connection between the threaded spindle and the threaded nut on the pump piston is retained even when the pump piston is arranged at its position in the fluid space that is maximally distant from the motor unit. A particularly safe movement of the pump piston in the fluid space between the end positions described above can be made possible in this way.

Alternatively, the door drive according to the invention can be characterized in that the pump piston has a piston plate sealed against the axial wall of the fluid space and a spindle section arranged on the piston plate, the spindle section being designed as a threaded spindle with an external thread for the threaded connection and the drive section having a cylindrical receiving area, preferably a receiving hole shaped as a blind hole for receiving the spindle section, the receiving area being designed at least in sections as a threaded nut with a corresponding internal thread, the threaded nut preferably being arranged at an end of the receiving area facing away from the motor unit. In contrast to the previously described embodiment of the door drive according to the invention, in the alternative embodiment now described, the elements of the threaded connection are swapped. The threaded spindle is designed as a spindle section of the pump piston and the receiving area for receiving this threaded spindle is provided by the drive shaft. The advantageous size relationships between the receiving area and the threaded spindle listed for the embodiment described above can also be used in the present embodiment.

The door drive according to the invention can preferably be designed in such a way that a sealing element, in particular comprising an O-ring and a piston sealing ring, is arranged all around the pump piston for sealing against the axial wall of the fluid space. By using an additional and specially designed sealing element, the space delimited by the pump piston can be sealed even better and more effectively. In this way, leakage rates can be further reduced or, preferably, even completely prevented.

The door drive according to the invention can also be designed in such a way that the drive piston is driven by a single stroke or several strokes, preferably one single stroke, the pump piston can be moved into an open position against the force of the closer spring. The volume of the pump chamber determines the amount of hydraulic fluid that is pumped into the pressure chamber in front of the drive piston during one stroke of the pump piston. The smaller this volume of the pump chamber is, the smaller the cross section of the pump chamber across the stroke and thus the smaller the force required to move the pump piston. On the other hand, correspondingly more strokes are then necessary in order to bring the pump piston completely into its open position. In other words, a smaller volume of the pump chamber enables a more compact design of the door drive according to the invention, but requires a longer opening process of the door due to the higher number of pump strokes that are usually required, and vice versa. In particular, the appropriate design of the hydraulic pump can be selected depending on the location and/or purpose of the door drive according to the invention.

The door drive according to the invention can also be designed in such a way that in the assembled state of the door drive, the opening position of the drive piston corresponds to an opening angle of the door between greater than 0° and 180°, in particular between 75° and 105°, preferably 90°. An opening angle between greater than 0° and 180° makes it possible, in particular, to freely select the opening area of the door. By having an opening angle of the door of 75° to 105°, in particular 90°, a sufficiently wide open door can be provided for the user of the door. The opening position of the drive piston can correspond to the maximum opening angle of the door, but also to a smaller opening angle.

According to a further development, it can also be provided in the door drive according to the invention that the door drive has a freewheel coupled to the drive mechanism, the freewheel being used to enable freewheeling functionality in the assembled state of the door drive after the drive piston has reached the opening position and for the duration of the arrangement of the drive piston in the open position, a movement of the door is decoupled from a movement of the drive piston. After the drive piston has moved into its open position and the resulting pretension of the closer spring, the freewheel functionality of the door drive according to the invention is activated by the freewheel. This decouples movement of the door from movement of the drive piston. For this purpose, the freewheel can be arranged, for example, between a drive shaft of the door drive and a linkage of the door drive. The freewheel enables an at least essentially resistance-free movement of the door or the door leaf of the door, in particular without being acted upon by the force of the closer spring. Overall, the door drive according to the invention can therefore be used as a partially automated or self-tightening freewheel closer.

The door drive according to the invention can also be designed in such a way that the pump piston is arranged in the fluid space between the pump space and the motor unit, whereby a pushing movement of the pump piston causes the hydraulic fluid to be applied to the drive piston in the opening direction in the pressure space. In other words, in this embodiment of the door drive according to the invention, the pump piston moves away from the motor unit in order to apply hydraulic fluid to the drive piston.

Alternatively, the door drive according to the invention can be designed in such a way that the pump chamber is formed in the fluid space between the pump piston and the motor unit, whereby a pulling movement of the pump piston results in the hydraulic fluid being applied to the drive piston in the opening direction in the pressure chamber. In contrast to the embodiment of the door drive according to the invention described above, in this embodiment the pump piston moves in when the hydraulic fluid is applied to the drive piston Direction of the motor unit. In special embodiments of the door drive according to the invention, such a pulling pump movement can enable a simpler and/or more compact design of the hydraulic pump. However, the pulling pump movement means that a seal of the pump chamber relative to the motor unit, especially in the area of a bearing of the drive shaft, has to withstand higher loads.

As stated above, the hydraulic pump of the door drive according to the invention can be designed to push or pull. Depending on the purpose and/or location of the door drive according to the invention, the most suitable variant of the hydraulic pump can be selected.

Furthermore, in the door drive according to the invention it can be provided that the pump chamber is connected not only to the pressure side but also to the suction side of the hydraulic pump, it being preferably provided that the pressure side and the suction side each have a check valve, with the check valve on the pressure side during a pumping movement of the pump piston opens and the check valve on the suction side closes and a suction movement of the pump piston closes the check valve on the pressure side and opens the check valve on the suction side. In particular, this configuration can be used for both pushing and pulling pump operation.

For example, in a simplest embodiment of the door drive according to the invention, the pump chamber can only be connected to the pressure chamber via the first hydraulic connection and without check valves. A pumping movement of the pump piston delivers the hydraulic fluid from the pump chamber as the pressure side of the hydraulic pump into the pressure chamber, while a suction movement of the pump piston then sucks the hydraulic fluid out of the pressure chamber via the first hydraulic connection, whereby the pump chamber forms the suction side of the hydraulic pump.

However, separate lines or hydraulic connections can preferably be present between the pump chamber and the pressure chamber, in which case the flow directions in the hydraulic connections can then be specified accordingly via check valves.

In particular, the hydraulic connection connected to the suction side of the hydraulic pump can also be connected to a correspondingly existing fluid reservoir in order to enable several pump strokes to be carried out without emptying the pressure chamber again every time hydraulic fluid flows into the pump chamber on the suction side. Once again, this is possible for both pushing and pulling pump operation. In particular, it can even be provided that a pump chamber is provided in the hydraulic pump on both sides of the pump piston, with both pump chambers being connected to both the pressure side and the suction side of the hydraulic pump and the hydraulic connections used having correspondingly switched check valves. In this way it is possible that, regardless of the direction of movement of the pump piston, one of the pump chambers always delivers hydraulic fluid into the pressure chamber and the other pump chamber sucks in hydraulic fluid from the fluid reservoir. Overall, a continuous delivery of hydraulic fluid can be made possible in this way.

According to a further preferred embodiment of the door drive according to the invention, it can further be provided that the pump piston delimits a reserve space in the fluid space connected to the suction side of the hydraulic pump on its side opposite the pump chamber, with a connecting line in the pump piston with a check valve for a flow of hydraulic fluid from the reserve chamber into the pump chamber is arranged when the pump piston moves in the direction of the storage chamber. In other words, in this embodiment, when the hydraulic fluid is conveyed from the pump chamber into the The pressure chamber of the reserve space is simultaneously enlarged, whereby hydraulic fluid flows into this reserve space. For the next stroke of the piston, it must be moved back to its starting position, with the connecting line with the correspondingly switched check valve in the pump piston allowing hydraulic fluid to flow from the storage space in the pressure chamber. After resetting the pump piston, the pump chamber is filled again with hydraulic fluid, which can be pumped back towards the pressure chamber during the next stroke of the pump piston.

In a special embodiment of the door drive according to the invention, it can be characterized in that the connecting line ends in the receiving area and has a bypass line for the hydraulic fluid to flow past the threaded connection into the receiving area of the pump piston and/or the external thread and/or the internal thread of the threaded connection have a recessed tooth root area and/or a shortened tooth head area. In this embodiment, the pump piston of the hydraulic pump is designed with a receiving area into which the drive section of the drive shaft, designed as a threaded spindle, can immerse. In order to enable hydraulic fluid to flow from the storage space into the pressure space, it is usually necessary for the hydraulic fluid to first flow from the storage space into the receiving area, and from there further into the pressure space. This can be done, for example, by a bypass line, which in particular encompasses the area of a threaded nut of the receiving area, or by the threaded connection, the internal and/or external thread of which is preferably designed accordingly. The latter has the additional advantage in particular that friction losses can be reduced by the hydraulic fluid in the threaded connection.

In an alternative special embodiment of the door drive according to the invention, it can be designed in such a way that the connecting line is arranged in the piston plate. This special embodiment of the door drive according to the invention relates to a hydraulic pump, the pump piston of which is designed as a piston plate with a spindle section arranged thereon. It is not necessary for the hydraulic fluid to flow into the receiving area, which is formed by the drive shaft in this embodiment. By arranging the connecting line only in the piston plate, it is still possible for hydraulic fluid to flow from the storage space into the pump space.

Preferably, the door drive according to the invention can further be characterized in that a check valve for preventing a flow of hydraulic fluid from the pressure chamber to the pump chamber is arranged in the first hydraulic connection. By means of such a check valve, a simultaneous flow of hydraulic fluid from the pressure chamber to the pump chamber can be reliably prevented, particularly when the pump piston is reset in the fluid chamber, in which hydraulic fluid flows from the reserve chamber into the pump chamber. The application of the hydraulic fluid present in the pressure chamber to the drive piston, and thus in particular the pretension of the closer spring, can be safely maintained in this way.

It can also be further provided in the door drive according to the invention that the hydraulic system has a second hydraulic connection which connects the pressure chamber, in particular via a drive piston interior, with a spring chamber in which the closer spring is arranged, an electrically switchable check valve for selectively releasing or preventing a flow from the pressure chamber into the spring chamber and thereby moving the drive piston in the closing direction. In this embodiment, the spring chamber is also filled with hydraulic fluid. After a When hydraulic fluid is applied to the drive piston, it is displaced axially, which also reduces the spring space. For a return movement of the drive piston, it is therefore necessary that, on the one hand, hydraulic fluid flows out of the pressure chamber and, on the other hand, that hydraulic fluid is refilled into the spring chamber. This can be achieved particularly easily via the second hydraulic connection. The electrically switchable check valve can in particular enable external control or triggering of this movement of the drive piston in the closing direction. By blocking the electrically switchable check valve, the drive piston remains in its deflected position, whereby the closer spring remains pretensioned.

In addition, in the door drive according to the invention it can be provided that at least one throttle valve for hydraulic damping of the movement of the drive piston in the closing direction is arranged in the second hydraulic connection. A throttle valve in a hydraulic connection determines the amount of hydraulic fluid that can flow through the hydraulic connection. The preferably adjustable throttle valve in the second hydraulic connection can therefore be used to determine how quickly hydraulic fluid can flow from the pressure chamber into the spring chamber, whereby a closing speed of the door can also be automatically adjusted.

In addition, the door drive according to the invention can be characterized in that the electrically switchable check valve is opened in a de-energized state and enables hydraulic fluid to flow from the pressure chamber into the second hydraulic connection. In other words, if the electrically switchable check valve is not activated, the drive piston moves in the closing direction, driven by the closer spring. A door equipped with the door drive according to the invention is therefore closed when the electrically switchable shut-off valve is in a de-energized state, in particular in the event of a complete power failure. closed or held in a closed position. This makes it possible to use the door drive according to the invention, for example on a fire protection door that must be closed safely in the event of a fire.

Alternatively, the door drive according to the invention can be characterized in that the electrically switchable check valve is blocked in a de-energized state and prevents hydraulic fluid from flowing from the pressure chamber into the second hydraulic connection. In this alternative embodiment of the door drive according to the invention, in particular the variant described above, the electrically switchable check valve is designed in such a way that it is closed when it is not actively energized. In other words, once a door has been opened, it remains in this open state even in the event of a power failure, since hydraulic fluid is prevented from flowing from the pressure chamber into the spring chamber. In a further preferred development, provision can even be made to control the door drive according to the invention when a triggering situation occurs, for example a fire or a power failure, in such a way that the corresponding door is opened and then held in the open position. For this purpose, the door drive according to the invention can, for example, have an additional electrical energy storage device in order to supply the hydraulic pump with electrical energy for opening the door once by applying hydraulic fluid to the pressure chamber. The shut-off valve, which locks when there is no power, then ensures that the door is kept open safely. The use of a door drive according to the invention as part of an RWA system (smoke-heat extraction) can be made possible in this way.

In particular, the door drive according to the invention can also be characterized in that the fluid space and the spring space are separated by a plate element, in particular a spring plate supporting the closer spring, the plate element having a, preferably deep-drawn, sleeve that is closed relative to the spring space and extends into the spring space and a sleeve room encloses, the sleeve space bordering the fluid space without any walls and the fluid space around the sleeve space is thereby enlarged, the sealing of the pump piston against the wall of the fluid space being arranged at an end of the pump piston facing the motor unit and a section of the pump piston during operation of the hydraulic pump at least temporarily extends into the sleeve space. In other words, in this embodiment the fluid space is at least partially arranged inside the spring space. This can preferably be promoted, for example, by designing the closer spring as a compression spring, in particular as a helical spring. Since this also automatically enables the pump piston to extend at least temporarily and in sections into the interior of the spring chamber during operation of the hydraulic pump, the entire door drive according to the invention can be designed to save space. In order to maximize this extension of the pump piston into the spring space, the seal and the threaded nut can both be arranged on the end of the pump piston facing the motor unit.

Alternatively, the door drive according to the invention can be designed in such a way that the fluid space and the spring space border one another without any walls, the seal of the pump piston against the wall of the fluid space being arranged at an end of the pump piston facing the motor unit and a section of the pump piston being at least partially in contact with the motor unit during operation Spring space extends. In this embodiment, the spring chamber thus at least essentially forms the suction side of the hydraulic pump. In this embodiment too, the pump piston extends into the spring chamber at least temporarily and in sections. This embodiment also enables a more compact and space-saving design of the door drive according to the invention. In order to maximize extension of the pump piston into the spring chamber, in this embodiment too, the seal and the threaded nut can both be located on the end facing the motor unit Pump piston can be arranged. In contrast to the variant described above, in which both pushing and pulling operation of the hydraulic pump is possible, in this alternative variant only pulling operation is possible.

Particularly preferably, the door drive according to the invention can be characterized in that the hydraulic system has a third hydraulic connection which connects the spring space with the fluid space, in particular the pump space or the storage space, the third hydraulic connection allowing a flow of hydraulic fluid when the drive piston is displaced in the opening direction of rotation the spring space into the fluid space. When the pump piston pumps, hydraulic fluid is delivered from the pressure side of the hydraulic pump to the pressure chamber, causing the drive piston to move against the force of the closing spring. This simultaneously reduces the size of the spring space, with the displaced hydraulic fluid continuing to flow via the third hydraulic connection back to the hydraulic pump, in particular to the suction side or to the reserve space forming the suction side of the hydraulic pump. In this embodiment, the spring chamber thus forms at least part of the fluid reservoir described above. Overall, in this embodiment, the hydraulic system together with the hydraulic pump, the pressure chamber and the spring chamber preferably represents a closed system. The corresponding volume changes that occur in the different rooms when operating the door drive according to the invention correspond in pairs, in particular the volume changes the pump room and the pressure room, the pressure room and the spring room, the spring room and the reserve room as well as the reserve room and the pump room. Additional fluid spaces, in particular, for example, expansion tanks for holding hydraulic fluid, can therefore be dispensed with in a door drive according to the invention.

The door drive according to the invention can also be characterized in that the first hydraulic connection and/or the second hydraulic connection and/or the third hydraulic connection is designed at least in sections as a bore, in particular a deep hole, in the housing of the door drive. In this way, the housing itself can be used to provide the hydraulic connections. Complex, especially external, additional line elements for the hydraulic connection can be avoided.

Furthermore, in the door drive according to the invention it can be provided that the fluid space is delimited on a side facing the electric motor unit by a bearing cover, the bearing cover having a bearing in which the drive shaft is axially fixed and radially mounted, the bearing cover preferably opposing the fluid space seals the environment. Through the bearing cover, three, preferably four, functions can be fulfilled by a single component, namely a delimitation of the fluid space, a storage of the drive shaft in the radial direction, a fixation of the drive shaft in the axial direction and preferably a sealing of the fluid space. Compared to a solution in which several components are required to fulfill these functions, installation space can be saved and the entire door drive according to the invention can be designed to be simpler and more compact.

Furthermore, the door drive according to the invention can be characterized in that the electric motor unit comprises a stepper motor and a planetary gear and/or a cycloid gear, wherein preferably the electric motor unit is arranged outside the housing and is attached to the housing, in particular to a housing cover. Stepper motors are electric motors that can be controlled particularly precisely, which enables particularly precise and simple adjustment of the hydraulic fluid conveyed by the hydraulic pump of the door drive according to the invention. A planetary gear or a Cycloidal gears, in turn, enable a particularly compact and space-saving translation of a speed of the stepper motor into a speed of the drive shaft with conversion of the motor torque into the required torque on the drive shaft. Another advantage of this type of geared stepper motor unit is the comparatively high torque provided given the required size and speed range. Arranging the electric motor unit on the outside of the housing can make it particularly easy to replace and/or retrofit the entire electric motor unit.

In summary, a simple motor can be arranged as a motor unit outside the housing. However, it is preferred that the motor unit, which is arranged accordingly outside the housing, is designed as a geared motor, as a stepper motor or even as a geared stepper motor. As stated above, the drive shaft of the motor can be designed, for example, as a threaded spindle. Alternatively, as also described above, a drive shaft with a threaded nut, into which a threaded spindle of the pump piston engages, is conceivable.

The invention is described below with reference to figures. Elements with the same function and mode of operation are given the same reference numbers in the figures.

Fig. 1

einen erfindungsgemäßen Türantrieb in einer Außenansicht,

Fig. 2

eine Schnittansicht einer ersten Ausführungsform des erfindungsgemäßen Türantriebs,

Fig. 3

eine Schnittansicht einer ersten Ausführungsform einer Hydraulikpumpe des erfindungsgemäßen Türantriebs,

Fig. 4

eine Schnittansicht einer zweiten Ausführungsform einer Hydraulikpumpe des erfindungsgemäßen Türantriebs,

Fig. 5

eine Schnittansicht einer dritten Ausführungsform einer Hydraulikpumpe des erfindungsgemäßen Türantriebs,

Fig. 6

eine Detailansicht der in Fig. 5 gezeigten Hydraulikpumpe,

Fig. 7

eine Schnittansicht einer vierten Ausführungsform einer Hydraulikpumpe des erfindungsgemäßen Türantriebs,

Fig. 8

eine Schnittansicht einer fünften Ausführungsform einer Hydraulikpumpe des erfindungsgemäßen Türantriebs,

Fig. 9

zwei Schnittansichten einer sechsten Ausführungsform einer Hydraulikpumpe des erfindungsgemäßen Türantriebs,

Fig. 10

eine Schnittansicht einer zweiten Ausführungsform des erfindungsgemäßen Türantriebs,

Fig. 11

eine Schnittansicht einer dritten, vereinfachten Ausführungsform des erfindungsgemäßen Türantriebs in einem ersten Betriebszustand,

Fig. 12

den erfindungsgemäßen Türantrieb von Fig. 11 in einem zweiten Betriebszustand,

Fig. 13

den erfindungsgemäßen Türantrieb von Fig. 11 in einem dritten Betriebszustand, und

Fig. 14

den erfindungsgemäßen Türantrieb von Fig. 11 in einem vierten Betriebszustand.

It shows schematically:

Fig. 1

a door drive according to the invention in an external view,

Fig. 2

a sectional view of a first embodiment of the door drive according to the invention,

Fig. 3

a sectional view of a first embodiment of a hydraulic pump of the door drive according to the invention,

Fig. 4

a sectional view of a second embodiment of a hydraulic pump of the door drive according to the invention,

Fig. 5

a sectional view of a third embodiment of a hydraulic pump of the door drive according to the invention,

Fig. 6

a detailed view of the in Fig. 5 hydraulic pump shown,

Fig. 7

a sectional view of a fourth embodiment of a hydraulic pump of the door drive according to the invention,

Fig. 8

a sectional view of a fifth embodiment of a hydraulic pump of the door drive according to the invention,

Fig. 9

two sectional views of a sixth embodiment of a hydraulic pump of the door drive according to the invention,

Fig. 10

a sectional view of a second embodiment of the door drive according to the invention,

Fig. 11

a sectional view of a third, simplified embodiment of the door drive according to the invention in a first operating state,

Fig. 12

the door drive according to the invention Fig. 11 in a second operating state,

Fig. 13

the door drive according to the invention Fig. 11 in a third operating state, and

Fig. 14

the door drive according to the invention Fig. 11 in a fourth operating state.

Fig. 1 shows a door drive 200 according to the invention in an external view. What is particularly visible here is a hood 202 of the door drive 200, which covers the housing 210 (cf. Fig. 2 ) of the door drive 200 according to the invention encloses. As shown by way of example, a drive shaft 228 protrudes from the hood 202 on an upper side and is connected to a drive mechanism 218 arranged in the housing 210 (cf. Fig. 2 ) is connected in a driving manner. Furthermore, a linkage 230, designed in particular as a lever, is shown, which ensures a driving coupling between a door leaf and a lintel of the corresponding door through the door drive 200 according to the invention mounted on it. In particular, as shown, the door drive 200 according to the invention can have a freewheel 226, which is arranged, for example, between the drive shaft 228 and the linkage 230. Such a freewheel 226 makes it possible to separate a movement of the drive shaft 228, and thereby the components of the drive mechanism 218 installed inside the housing 210, from a movement of the door leaf of the door. In the illustrated embodiment, all of the elements of the door drive 200 according to the invention necessary for the actual drive, in particular for the hydraulic drive, are arranged inside the housing 210. This illustrates the advantage of the door drive 200 according to the invention of being particularly compact and requiring little installation space.

In Fig. 2 an embodiment of the door drive 200 according to the invention is shown in a sectional view. In particular, it is a particularly simple embodiment of the door drive 200 according to the invention. Inside the Housing 210 is, on the one hand, provided with a hydraulic cylinder 212, in which the drive mechanism 218 is arranged. In particular, an axially displaceable drive piston 220 and a closing spring 224 which applies a force to the drive piston 220 are arranged in the hydraulic cylinder 212. The section of the hydraulic cylinder 212 in which the closing spring 224 is arranged is also called the spring chamber 216. The drive shaft 228 is coupled to the drive piston 220 via a meshing engagement as an operative connection, so that an axial movement of the drive piston 220 in the hydraulic cylinder 212 causes a rotation of the drive shaft 228 and vice versa.

A hydraulic drive is provided in the door drive 200 according to the invention for movement of the drive piston 220 in the hydraulic cylinder 212. This hydraulic drive includes in particular a hydraulic pump 10, which has an electric motor unit 30 as a drive. According to the invention, the hydraulic pump 10 is designed as a piston pump. A pump piston 50 is arranged in a fluid space 12 and is sealed from a wall 18 of the fluid space 12, as shown preferably via a circumferential sealing element 56, for example comprising an O-ring and a piston sealing ring. This enables particularly low leakage rates for the entire hydraulic pump 10. A translational pumping or suction movement of the pump piston 50 in the fluid space 12 is driven via a drive shaft 32 of the motor unit 30, which, according to the invention, is connected to the pump piston 50 in a drive-effective manner with its drive section 34 via a threaded connection 70.

The use of a threaded connection 70 brings with it several advantages. The threaded connection 70, which can be designed as a standard thread, but preferably also, for example, as a trapezoidal thread, a buttress thread, a ball screw or a roller thread, can be used to convert the rotational movement of the drive shaft 32 into a translational movement particularly easily and safely Pump piston 50 can be converted, whereby high forces can be transmitted at the same time. High pumping pressures can thus be generated by the hydraulic pump 10 of the door drive 200 according to the invention. By dispensing with complex mechanics for moving the pump piston 50 in the fluid space 12, comprising, for example, a connecting rod or linkage mechanism, a particularly compact design of the hydraulic pump 10 can also be made possible, which also has a low level of noise during operation.

As in Fig. 2 shown, the motor unit 30 can also be arranged outside the housing 210 and attached or flanged to it. In this case, it can be provided in particular that the housing 210 and the motor unit 30 are covered by a common cover. The motor unit 30 preferably has an electric motor 36, for example a stepper motor, and a gear 38, for example a planetary gear and/or a cycloid gear, whereby accurate and precise control and/or regulation of a rotational speed of the drive shaft 32 can be achieved. The drive shaft 32 is preferably supported by a bearing cover 40, which closes the fluid space 12 at one end, with the bearing 42 provided for this purpose in particular effecting both radial storage and axial fixation of the drive shaft 32.

As already stated above, shows Fig. 2 a particularly simple embodiment of the door drive 200 according to the invention, particularly with regard to the installed hydraulics. The pump piston 50 delimits a pump chamber 14 in the fluid space 12, which has a variable size when the pump piston 50 is axially displaced. This pump chamber 14 is fluidly connected to a pressure chamber 214 via a first hydraulic connection 92 of a hydraulic system 90 of the door drive 200 according to the invention, the pressure chamber 214 being located on the side of the drive piston opposite the closer spring 224 220 is located.

A movement of the pump piston 50, which leads to a reduction in the size of the pump chamber 14, thus conveys hydraulic fluid 102 from the pump chamber 14 into the pressure chamber 214. As a result, the drive piston 220 is displaced against the force of the closing spring 224, at the same time, mediated via the drive mechanism 218 , the drive shaft 228 and the linkage 230 (not shown), the door opens and / or the closer spring 224 is pretensioned. In other words, when the pump piston 50 moves as described above, the pump chamber 14 forms the pressure side 20 of the hydraulic pump 10. When the pump piston 50 moves in the opposite direction, in Fig. 2 to the right in the direction of the motor unit 30, which leads to an enlargement of the pump chamber 14, hydraulic fluid 102 is sucked back from the pressure chamber 214 into the pump chamber 14 via the first hydraulic connection 92, whereby the pump chamber 14 is therefore also connected to the suction side 22 of the hydraulic pump 10 . The associated movement of the drive piston 220 in the closing direction is additionally supported by the preloaded closer spring 224.

The various embodiments of the door drive 200 according to the invention differ in particular in the structure of the hydraulic pump 10 used in each case, as well as in the different hydraulic systems 90 and the rooms connected thereby. The following are in the Figures 3 to 9 various possible embodiments of hydraulic pumps 10 of the door drive 200 according to the invention are described. All of these hydraulic pumps 10 have in common the feature essential to the invention of a pump piston 50 driven by a threaded connection 70. The hydraulic pumps 10 shown in FIGS. 3 to 9 are described below, with particular attention to the differences between the individual variants. To avoid repetition, components that are present in several of the variants are not described again for each variant.

Fig. 3 shows a detailed view of a possible hydraulic pump 10 of a door drive 200 according to the invention. Like all of these hydraulic pumps 10, this one also has a motor unit 30, which includes an electric motor 36 and a gear 38 for driving a drive shaft 32. The drive shaft 32 in turn is supported radially by a bearing 42 and fixed axially. The bearing 42 is arranged in a bearing cover 40, which in turn delimits a fluid space 12 of the hydraulic pump 10. The fluid space 12 is otherwise arranged in a housing 210 of the door drive 200. A pump piston 50 is mounted in an axially displaceable manner in the fluid space 12. In this embodiment too, the pump piston 50 is sealed against a wall 18 of the fluid space 12 via a circumferential sealing element 56 and is delimited in the fluid space 12 by a pump space 14. As already shown in FIG Fig. 2 In the variant shown, this pump chamber 14 is connected to both the pressure side 20 and the suction side 22 of the hydraulic pump 10.

In contrast to the in Fig. 2 The embodiment of a hydraulic pump 10 shown is in the in Fig. 3 In the embodiment shown, in addition to the first hydraulic line 92, which is connected to the pressure side 20 of the hydraulic pump 10, a further hydraulic connection is provided, which is connected to the suction side 22 of the hydraulic pump 10. A check valve 98 is provided in both hydraulic connections 92, so that during a pumping movement of the pump piston 50, hydraulic fluid 102 is only delivered via the pressure side 20 of the hydraulic pump 10 and, similarly, during a suction movement of the pump piston 50, hydraulic fluid 102 is only delivered via the suction side 22 of the hydraulic pump 50 Pump chamber 40 is sucked in or pushed in.

In Fig. 3 a pressing operation of the hydraulic pump 10 is shown. By a corresponding, not shown, arrangement of the first hydraulic line 92 to that part of the fluid space 12 which is between the pump piston 50 and the motor unit 30 is located, which can be related to Fig. 3 Features and advantages described can also be made possible when the hydraulic pump 10 is in pulling mode. In particular, through an appropriate arrangement of hydraulic lines with corresponding check valves (also not shown), both volumes formed by the pump piston 50 in the fluid space 12 can be used as pump spaces 14, which, depending on the direction of movement of the pump piston 50, alternate with the pressure side 20 or the suction side 22 of the hydraulic pump 10 are connected. As a result, in particular, a continuous delivery operation of the hydraulic pump 10 can be achieved.

The following is based on the Fig. 3 the threaded connection 70 of the hydraulic pump 10, which is essential to the invention, is described in more detail. As shown, the drive shaft 32, in particular its drive section 34, can be designed as a threaded spindle 72 with an external thread 80. In turn, a receiving area 74 is provided in the pump piston 50, into which the drive section 34 of the drive shaft 32 can be immersed, preferably completely. This receiving area 74 is designed in sections as a threaded nut 76 with an internal thread 78, the external thread 80 of the threaded spindle 72 and the internal thread 78 of the threaded nut 76 corresponding to one another, engaging with one another and in this way forming the threaded connection 70.

As shown, the threaded nut 76 can preferably be arranged on an end of the pump piston 50 facing the motor unit 30. In addition, in the illustrated embodiment of the hydraulic pump 10 it is provided that an axis of the threaded connection 70 is arranged offset from a central axis of the pump piston 50. Due to the form fit formed thereby, a rotationally fixed arrangement of the pump piston 50 in the fluid space 12 can be ensured in a particularly simple manner. At the same time, this makes it possible for the fluid space 12 and the pump piston 50, the latter at least in Area of sealing relative to the wall 18 of the fluid space 12 can be cylindrical with a circular cross section, whereby the sealing of the pump piston 50 relative to the fluid space 12 is simplified.

In Fig. 4 is a variation of the in Fig. 3 hydraulic pump 10 shown. For elements of the hydraulic pump 10 not described below Fig. 4 will therefore refer to the corresponding description of the hydraulic pump 10 Fig. 3 referred. In particular, the threaded connection 70 is designed the same in both variants of the hydraulic pump 10. In contrast to that in Fig. 3 Hydraulic pump 10 shown, has the in Fig. 4 Hydraulic pump 10 shown in addition to the pump chamber 14 also has a reserve chamber 16. Both the pump chamber 14 and the reserve chamber 16 are designed as parts of the fluid chamber 12 and are delimited by the pump piston 50 and separated from one another by the latter. Furthermore, the pump chamber 14 is connected to the pressure side 20 of the hydraulic pump 10 and is fluidly connected to the pressure chamber 214, not shown, of the door drive 200 according to the invention via a first hydraulic connection 92, in which a check valve 98 is arranged. The reserve space 16, in turn, which is located on the opposite side of the pump piston 50 with respect to the pump space 14, is fluidly connected to the suction side 22 of the hydraulic pump 10 and also to a hydraulic connection. This has the particular advantage that, during a pumping movement of the pump piston 50, in which the pump chamber 14 is reduced, the reserve chamber 16 simultaneously increases, on the one hand hydraulic fluid 102 is conveyed from the pressure side 20 of the hydraulic pump 10 and at the same time new hydraulic fluid 102 is supplied the suction side 22 of the hydraulic pump 10 flows into the storage space 16. After completing a stroke of the pump piston 50, it is arranged at a left end of the fluid space 12, whereby the volume of the pump space 14 is minimal and the volume of the reserve space 16 is maximum.

To be able to carry out another stroke, for example if a single If the stroke is not sufficient for a complete opening of the door equipped with the door drive 200 according to the invention, the pump piston 50 must be reset, in other words partially, preferably completely, shifted to the right in the fluid space 12. So that the hydraulic fluid 102 present in the storage space 16 can flow into the pump space 14 at the same time, a connecting line 60 is arranged in the pump piston 50. A check valve 98 in the connecting line ensures, in particular, that hydraulic fluid 102 only flows through the connecting line 60 during the resetting movement of the pump piston 50 and that the connecting line 60 is blocked during a pumping movement of the pump piston 50.

Fig. 5 shows a slight modification of the one already in Fig. 4 Hydraulic pump 10 shown, reference is made to the description above. At the in Fig. 5 The variant of the hydraulic pump 10 shown is compared to that in Fig. 4 In the variant shown, the pressure side 20 and the suction side 22 of the hydraulic pump 10 are swapped. Of all the other components, only the hydraulic valve 98 is arranged exactly upside down in the connecting line 60. In other words shows Fig. 5 an embodiment of the hydraulic pump 10 for pulling operation, whereas Fig. 4 shows a variant of the hydraulic pump 10, which is designed for pressing operation. As a result, however, all of them can already be referred to Fig. 4 described functions of the hydraulic pump 10, in particular the resetting of the pump piston 50 after executing a stroke, also through the variant of the hydraulic pump 10 Fig. 5 be made possible.

As described above, when the respective pump piston 50 is reset, the flows into the Fig. 4 , 5 shown hydraulic pumps 10 hydraulic fluid 102 from the reserve space 16 into the pump chamber 14, in particular regardless of which side of the pump piston 50 with respect to the motor unit 30 the respective reserve chamber 16 or pump chamber 14 is arranged is. Like in the Fig. 4 , 5 shown, a connecting line 60 with a check valve 98 is provided, which in particular connects the receiving area 74 in the pump piston 50 with the pump chamber 14 ( Fig. 4 ) or the storage room 16 ( Fig. 5 ) connects. In both variants, the hydraulic fluid 102 must first flow into the receiving area 74.

Possible solutions for this are for the in Fig. 4 shown embodiment of the hydraulic pump 10 as a detailed view in Fig. 6 shown. For example, the connecting line 60 may include a bypass line 62, which allows the hydraulic fluid 102 to flow past the threaded connection 70. Alternatively or additionally, the external thread 80 of the threaded spindle 72 and/or the internal thread 78 of the threaded nut 76 can also have a recessed tooth root area 82 and/or a shortened tooth head area 84. In this way too, hydraulic fluid 102 can flow from the corresponding part of the fluid space Fig. 6 from the storage space 16 into the receiving area 74 can be made possible.

Solutions for the hydraulic pump 10 of Fig. 5 is obtained based on the in Fig. 6 shown embodiment by replacing the storage space 16 with the pump space 14 and by reversing the flow direction of the hydraulic fluid 102.

A variant of the hydraulic pump 10 that is significantly different from the possible embodiments of the hydraulic pump 10 shown so far is in Fig. 7 shown. Here too, the hydraulic pump 10 has, in addition to the usual components such as motor 30, a pump chamber 14 and a holding chamber 16 as parts of the fluid chamber 12, which are separated from one another by the pump piston 50. However, the structure of the pump piston 50 and the drive section 34 of the drive shaft 32 differ from those in Fig. 7 illustrated variant of Hydraulic pump 10 from the possible embodiments of hydraulic pumps 10 described above.

The pump piston 50 has in particular a piston plate 52, which carries the sealing element 56 for sealing against the wall 18 of the fluid space 12. Furthermore, the connecting line 60 and the corresponding check valve 98 are arranged in the piston plate 52. A spindle section 54 is provided on the piston plate 52, which is designed as a threaded spindle 72 and extends in the direction of the motor unit 30. To accommodate this spindle section 54, the drive shaft 32, in particular its drive section 34, now has a receiving area 74 into which the spindle section 54 can be immersed, preferably completely, as shown. At the end of the receiving area 74 facing away from the motor unit 30, this is designed as a threaded nut 76, which carries an internal thread 78 and thus engages in the external thread 80 of the threaded spindle 72. In order to enable an exchange of hydraulic fluid 102 between the storage space 16 and the receiving area 74, analogous to those in Fig. 6 In the solutions shown, compensation bores 62 can be provided in the drive section 34 and/or in the threaded spindle 72 or corresponding configurations of the threaded connection 70. In this way, the threaded connection 70 which is essential to the invention is also formed in this embodiment for driving the axial displacement of the pump piston 50 in the fluid space 12. Furthermore, as shown, an axial offset can also be provided in this embodiment for the rotationally fixed arrangement of the pump piston 50 in the fluid space 12 between the threaded connection 70 and the fluid space 12.

Another possible embodiment of the hydraulic pump 10 is in Fig. 8 shown. In this embodiment of the door drive 200 according to the invention, in which the hydraulic pump 10 Fig. 8 is installed, the spring chamber 216 is also filled with hydraulic fluid 102. In particular, the fluid space 12 of the hydraulic pump 10 and the spring space 216 border one another without any walls. In other words no separation between the spring space 216 and the fluid space 12 is required. At the same time, the seal of the pump piston 50 against the wall 18 of the fluid space, in particular provided by the sealing element 56, is arranged at an end of the pump piston 50 facing the motor unit 30. As a result, the pump piston 50 can at least temporarily extend into the spring space 216 during an axial displacement driven by the motor unit 30. If, as shown, the closer spring 224 is designed as a compression spring, in particular as a helical spring, the pump piston 50 can preferably even extend into the interior of the closer spring 224, which enables a particularly compact design of the door drive 200 according to the invention. In other words, the spring space 216 essentially forms the suction side 22 of the hydraulic pump 10. A separately provided reserve space 16 (in Fig. 8 not shown) of the hydraulic pump 10 can therefore be omitted. Overall, with this structure, only pulling operation of the hydraulic pump 10 is possible. In summary, in this way a particularly simple, compact and space-saving embodiment of the hydraulic pump 10 and, as a result, also of the door drive 200 according to the invention can be made possible. Otherwise, the hydraulic pump 10 is like the one already referred to Fig. 5 described variant of the hydraulic pump 10.

Fig. 9 shows a further variant of the hydraulic pump 10 in two sectional views, in which the pump piston 50 also extends at least partially into the spring chamber 216. Figure A shows a section through the entire door drive 200, Figure B shows a perspective section through elements of the corresponding hydraulic pump 10.

In contrast to that in Fig. 8 In the variant shown, the fluid space 12 is sealed from the spring space 216. For this purpose, in particular, a plate element 110 is provided, which is arranged between the spring space 216 and the fluid space 12 is. In particular, the plate element can be a spring plate 112 that supports the closer spring 24. This plate element 110 has, for example, a deep-drawn sleeve 114 that is closed relative to the spring space 216 and extends from the plate element 110 into the spring space 216. By designing the closer spring 224 as a compression spring, in particular as a helical spring, the sleeve 114 can preferably also extend into the interior of the closer spring 224. The sleeve space 116 formed inside the sleeve 114 borders the fluid space 12 without walls, as a result of which the fluid space 12 is enlarged by the volume of the sleeve space 116. Overall, the pump piston 50 can also extend in the part of the fluid space 12 formed by the sleeve space 116. Which already in relation to Fig. 8 The advantages described with regard to a particularly compact and space-saving embodiment of the hydraulic pump 10 and, as a result, also of the door drive 200 according to the invention can therefore also be achieved through the in Fig. 9 shown embodiment of the hydraulic pump 10 can be made possible.

As shown, for example, the sleeve space 116 can form the reserve space 16 of the hydraulic pump 10 as part of the fluid space 12. As already described above for other embodiments of the hydraulic pump 10, a connecting line 60 with a check valve 98 is arranged in the pump piston 50, which allows hydraulic fluid 102 to flow from the storage space 16 into the pump space 14 when the pump piston 50 is reset. In the Fig. 9 The variant shown thus allows, in other words and in particular in contrast to the one in Fig. 8 shown embodiment also a pushing operation of the hydraulic pump 10, with at least essentially the same space requirements. However, a pulling operation can also be realized by a corresponding design, in particular by swapping the suction side 22 and pressure side 20 or the storage space 16 and the pump space 14, as well as by turning the check valve 98 in the connecting line 60.

Regardless of the differences described above, in Fig. 9 illustrated variant of the hydraulic pump 10 also provides that the fluid space 12 and the threaded connection 70 are arranged without mutual axial offset. In order to achieve a rotationally fixed arrangement of the pump piston 50 in the fluid space 12, the pump piston 50 is accommodated in the fluid space 12 in a form-fitting manner in the circumferential direction. In order to achieve this, the otherwise circular cross section of the pump piston 50, in particular the cross section of the section of the pump piston 50 guided through the receptacle in the plate element 110, and of the fluid space 12, in particular the corresponding cross section of the receptacle of the plate element 110, is designed to be partially linearly flattened, see in particular Figure B of the Fig. 9 . In other words, the receptacle in the plate element 110 and the corresponding section of the pump piston 50 have a respective contour that is designed to be positively coordinated with one another.

Fig. 10 shows a possible embodiment of the entire door drive 200 according to the invention in a sectional view. In addition to the hydraulic drive components, in particular comprising the hydraulic pump 10, the door drive 200 according to the invention has mechanical components, for example a closer spring 224, through which a mechanical, in particular independent, closer functionality of the door drive 200 can be made possible. The representation of the Fig. 10 is particularly aimed at the hydraulic function of the door drive 200 according to the invention. Therefore, only the components of the door drive 200 according to the invention that are essential for this operation are described below.

In this embodiment too, the hydraulic pump 10 has a pump piston 50 which can be axially displaceable via a motor unit 30 and which is coupled to the motor unit 30 via a threaded connection 70. The hydraulic pump 10 points a pressure side 20 and a separate suction side 22, whereby a pump chamber 14 of the hydraulic pump 10 is connected to the pressure side 20 and a reserve chamber 16, which is separated from the pump chamber 14 by the pump piston 50, is connected to the suction side 22 of the hydraulic pump 10.

Furthermore, the door drive 200 shown has a hydraulic system 90 with several hydraulic connections 92, 94, 96, 104. Preferably, at least parts of these hydraulic connections 92, 94, 96, 104 can be designed as deep holes in the housing 210 of the door drive 200 according to the invention. Thus, the pump chamber 14 of the hydraulic pump 10 is connected via a first hydraulic connection 92, in which a correspondingly arranged check valve 98 is placed, to the pressure chamber 214, which is arranged on the side of the drive piston 220 facing away from a closing spring 224. A second hydraulic connection 94 enables hydraulic fluid 102 to flow between the pressure chamber 114 and the spring chamber 216, in particular the hydraulic fluid 102 also flows through the drive piston interior 222. A third hydraulic connection 96 in turn enables hydraulic fluid 102 to flow from the spring chamber 216 to the reserve chamber 16 of the hydraulic pump 10. A fourth hydraulic connection 104 enables hydraulic fluid 102 to flow from the spring chamber 216 in particular by means of a check valve 98 arranged accordingly in the fourth hydraulic connection 104 the pressure chamber 214. In particular, an electrically switchable check valve 300 is arranged in the second hydraulic connection 94. This check valve 300 can be closed or opened with appropriate electrical control. Both alternatives of the check valve 300 can be used in a door drive 200 according to the invention, namely that the check valve 300 is closed when energized or that the check valve is opened when energized. Below, the door drive 200 shown according to the invention is initially described in general terms with reference to the check valve 300, and finally the two design variants of the check valve 300 are also discussed. Further are also in the second Hydraulic connection 94 throttle valves 100 and another check valve 98 available.

Possible processes of operation of this in Fig. 10 Door drive 200 according to the invention shown is described below. Without operating the hydraulic pump 10, the door drive 200 according to the invention can be operated as a normal hydraulically damped door closer. An opening movement of the door leads to a displacement of the drive piston 220 against the force of the closing spring 224, with hydraulic fluid 102 simultaneously flowing from the spring chamber 216 into the pressure chamber 214 via the drive piston interior 222 and the fourth hydraulic line 104.

Depending on the setting of the electrically switchable check valve 300, there are now two options. When the check valve 300 is closed, following the deflection, the drive piston 220 is held in its deflected position by the hydraulic structure of the door drive 200 according to the invention, since hydraulic fluid 102 is prevented from flowing out of the pressure chamber 214. A freewheel 226 (see. Fig. 1 ) can be provided, which in this case still allows the door to move at least essentially without resistance.

Alternatively, the electrically switchable check valve 300 can be opened to allow hydraulic fluid 102 to flow into the second hydraulic connection 94, so that when the door is released, the closing spring 224 presses the drive piston 220 back into its starting position and at the same time presses hydraulic fluid 102 back into the spring chamber via the second hydraulic connection 94 216 flows. Here, the two, preferably adjustable, throttle valves 100 arranged in the second hydraulic connection 94 and the additional check valve 98 ensure that the closing speed (through the in Fig. 10 right throttle valve 100 shown) and at the same time for a so-called final stroke functionality, in which the door can be accelerated at the end of its closing movement in order to guarantee an absolutely safe closing of the door, for example by engaging a latch (through the in Fig. 10 left throttle valve 100 shown and the check valve 98 present in the associated branch of the second hydraulic connection 94).

Alternatively, at least hydraulic opening of the door is also possible, driven via the hydraulic pump 10 of the door drive 200 according to the invention. In the following Fig. 11 to 14 is the one in Fig. 10 shown embodiment of the door drive 200 according to the invention is shown in further illustrations, each of which only shows the hydraulic components necessary for the hydraulically driven operation of the door drive 200 according to the invention. For simplicity and to avoid repetition, the hydraulically driven operation of the door drive 200 according to the invention is described below with reference to Fig. 11 to 14 described. With regard to features of the door drive 200 according to the invention that are not described below, reference is made to the above description, in particular Fig. 10 , referred.

Fig. 11 shows an initial state for the hydraulically driven operation of the door drive 200 according to the invention. The pump piston 50 is located in the fluid space 12 in such a position that a volume of the pump space 14 is maximized and a volume of the storage space 16 is minimized. As the pressure side 20 of the hydraulic pump 10, the pump chamber 14 is connected to the pressure chamber 214 in front of the drive piston 220 via the first hydraulic connection 92, in which a correspondingly arranged check valve 98 is placed. A second hydraulic connection 94, in which the electrically switchable check valve 300 is arranged, connects the pressure chamber 214 with the spring chamber 216, with a flow of hydraulic fluid via a throttle valve 100 in this second hydraulic connection 94 102 can be regulated. The spring chamber 216, in which in particular the closer spring 224 is arranged, is in turn connected to the reserve chamber 16 of the hydraulic pump 10 via a third hydraulic connection 96. For the reset of the pump piston 50, which is also described below (cf. Fig. 13 ) in particular also has a connecting line 60 with a check valve 98.

Fig. 12 shows a hydraulically or electrohydraulically driven displacement of the drive piston 220 against the force of the closing spring 224. For this purpose, the pump piston 50, driven by the motor unit 30, was displaced in the fluid space 12 and the hydraulic fluid 102 present in the pump space 14 was thereby conveyed into the pressure space 214. Since the electrically switchable check valve 300 is closed, this leads to a displacement of the drive piston 220 in the direction of its open position and thus, for example, to an opening movement of the door and / or to a prestressing of the closer spring 224. This open position of the drive piston 220 can, for example, an opening angle of the door between greater than 0° and 180°, in particular between 75° and 105°, preferably 90°. At the same time, the displacement of the drive piston 220 reduces the size of the spring chamber 216, whereby hydraulic fluid 102 is automatically pressed from the spring chamber 216 via the third hydraulic connection 96 into the reserve chamber 16 of the hydraulic pump 10, which is connected to the suction side 22 of the hydraulic pump 10.

In order to be able to carry out a new stroke with the pump piston 50, it must be reset inside the hydraulic pump 10. This is in Fig. 13 shown. Driven by the motor unit 30, the pump piston 50 is displaced in the fluid space 12 in such a way that the volume of the pump space 14 increases again and at the same time the volume of the reserve space 16 decreases. The hydraulic fluid 102 displaced in this way from the storage space 16 flows into the pump chamber 14 via the connecting line 60 and the correspondingly arranged check valve 98. In this way, for example, it can be made possible to reach the open position of the drive piston 220 using several strokes of the pump piston 50 or to increase the possible achievable range of open positions of the drive piston 220 expand.

Fig. 14 now shows the state of the door drive 200 according to the invention, if starting from the state of Fig. 13 the electrically switchable check valve 300 is opened. Hydraulic fluid 102 can flow from the pressure chamber 214 into the spring chamber 216 via the second hydraulic connection 94 and the throttle valve 100 arranged therein. In this way, the drive piston 220 is pushed back into its starting position, in particular by the mechanical energy stored in the closer spring 224.

In particular, it can preferably be provided that this open state of the electrically switchable check valve 300 is also assumed in the de-energized state of the check valve 300. In other words, the check valve 300 is closed when energized. In particular, a displacement of the drive piston 220 into its starting position can be ensured even in the event of a power failure. It can be possible to use the door drive 200 according to the invention on fire doors, for which it must be ensured that the corresponding door is closed or kept closed in the event of a fire, in particular in the event of a power failure in the event of a fire.

Alternatively, the electrically switchable check valve 300 can also be designed such that it is open in the energized state and remains closed in the de-energized state. In this case, it can be ensured that the drive piston 220 remains in place even in the event of a power failure after previously carried out hydraulic testing Deflection remains in this deflected position. This makes it possible to keep the corresponding door open, for example as an escape route or as a supply air area for an SHEV system.

Reference symbol list

10

hydraulic pump

12

Fluid space

14

Pump room

16

Reserve room

18

wall

20

Print page

22

suction side

30

Motor unit

32

drive shaft

34

Drive section

36

Electric motor

38

transmission

40

Bearing cap

42

camp

50

pump piston

52

Piston plate

54

Spindle section

56

Sealing element

60

connecting line

62

Bypass line

70

Thread connection

72

threaded spindle

74

Recording area

76

threaded nut

78

inner thread

80

External thread

82

Tooth base area

84

Tooth tip area

90

Hydraulic system

92

First hydraulic connection

94

Second hydraulic connection

96

Third hydraulic connection

98

check valve

100

Throttle valve

102

Hydraulic fluid

104

Fourth hydraulic connection

110

Plate element

112

spring plate

114

sleeve

116

Sleeve space

200

Door drive

202

Hood

210

Housing

212

Hydraulic cylinder

214

Pressure room

216

Spring room

218

Drive mechanics

220

Drive piston

222

Drive piston interior

224

Closer spring

226

Freewheel

228

drive shaft

230

linkage

300

Check valve

Claims (27)

Door drive (200) for a door, comprising a housing (210) with a hydraulic cylinder (212), a drive mechanism (218) which can be coupled to the door and is arranged in the hydraulic cylinder (212) and has a displaceable drive piston (220) and a closer spring (224) which acts on the drive piston (220) in the closing direction of the door, the one opposite the closer spring (224). A pressure chamber (214) is formed on the side of the drive piston (220) for applying a hydraulic fluid (102) to the drive piston (220) in the opening direction of the door, a hydraulic system (90), and a hydraulic pump (10) for conveying the hydraulic fluid (102) into the pressure chamber (214), characterized, in that the hydraulic pump (10) is designed as a piston pump with a pump piston (50) which is axially displaceable and rotationally fixed in a fluid space (12) and is sealed against a wall (18) of the fluid space (12) and which has a pump piston (50) connected to the pressure side (20). the pump chamber (14) connected to the hydraulic pump (10), the hydraulic system (90) having a first hydraulic connection (92) which connects the pump chamber (14) to the pressure chamber (214), wherein the hydraulic pump (10) comprises an electric motor unit (30) with a drive shaft (32) and a drive section (34) of the drive shaft (32) is coupled to the pump piston (50) via a threaded connection (70) in order to drive the pump piston (50 ) to move axially in the fluid space (12) and thereby carry out a stroke of the pump piston (50). Door drive (200) according to claim 1,
characterized,
that an axis of the threaded connection (70) is arranged offset from a central axis of the pump piston (50) in order to arrange the pump piston (50) in a rotationally fixed manner in the fluid space (12). Door drive (200) according to claim 1 or 2,
characterized,
that for the rotation-proof arrangement of the pump piston (50) in the fluid space (12), the pump piston (50) is received in a form-fitting manner in the circumferential direction in the fluid space (12), in particular wherein the pump piston (50) and the wall (18) of the fluid space (12) are one have a different shape from a circle and/or wherein a guide groove is provided on the pump piston (50) and a corresponding guide pin is provided on the wall (18) of the fluid space (12), or vice versa. Door drive (200) according to one of the preceding claims,
characterized,
that the threaded connection (70) is designed as a trapezoidal thread, a buttress thread, a ball screw or a roller thread. Door drive (200) according to one of the preceding claims,
characterized,
that for the threaded connection (70), the drive section (34) is designed as a threaded spindle (72) with an external thread (80) and the pump piston (50) has a receiving area (74), preferably a receiving bore, for receiving the threaded spindle (72), wherein the receiving area (74) at least in sections as a threaded nut (76) with a corresponding internal thread (78), the threaded nut (76) preferably being arranged on an end of the pump piston (50) facing the motor unit (30). Door drive (200) according to one of the preceding claims 1 to 4,
characterized,
in that the pump piston (50) has a piston plate (52) sealed against the axial wall (18) of the fluid space (12) and a spindle section (54) arranged on the piston plate (52), the spindle section (54) being used for the threaded connection (70). is designed as a threaded spindle (72) with an external thread (80) and the drive section (34) has a cylindrical receiving area (74), preferably a receiving hole shaped as a blind hole, for receiving the spindle section (54), the receiving area (74) being at least partially is designed as a threaded nut (76) with a corresponding internal thread (78), the threaded nut (76) preferably being arranged at an end of the receiving area (74) facing away from the motor unit (30). Door drive (200) according to one of the preceding claims,
characterized,
in that a sealing element (56), in particular comprising an O-ring and a piston sealing ring, is arranged circumferentially on the pump piston (50) to seal against the axial wall (18) of the fluid space (12). Door drive (200) according to one of the preceding claims,
characterized,
that the drive piston (220) can be moved into an open position against the force of the closing spring (224) by a single stroke or several strokes, preferably a single stroke, of the pump piston (50). Door drive (200) according to claim 8,
characterized,
that in the assembled state of the door drive (200), the opening position of the drive piston (220) corresponds to an opening angle of the door between greater than 0° and 180°, in particular between 75° and 105°, preferably 90°. Door drive (200) according to one of the preceding claims 8 or 9, characterized in
in that the door drive (200) has a freewheel (226) coupled to the drive mechanism (218), the freewheel (226) to enable freewheeling functionality in the assembled state of the door drive (200) after the drive piston (220) has reached the open position and For the duration of the arrangement of the drive piston (220) in the open position, a movement of the door is decoupled from a movement of the drive piston (220). Door drive (200) according to one of the preceding claims,
characterized,
that the pump piston (50) is arranged in the fluid space (12) between the pump space (14) and the motor unit (30), whereby a pushing movement of the pump piston (50) for applying the hydraulic fluid (102) to the drive piston (220) in the opening direction in the pressure chamber (214). Door drive (200) according to one of the preceding claims 1 to 10,
characterized,
in that the pump chamber (14) is formed in the fluid chamber (12) between the pump piston (50) and the motor unit (30), whereby a pulling movement of the pump piston (50) for applying the hydraulic fluid (102) to the drive piston (220) in the opening direction in the pressure chamber (214). Door drive (200) according to one of the preceding claims,
characterized,
in that the pump chamber (14) is connected not only to the pressure side (20) but also to the suction side (22) of the hydraulic pump (10), it being preferably provided that the pressure side (20) and the suction side (22) each have a check valve (98). have, wherein when the pump piston (50) pumps, the check valve (98) of the pressure side (20) opens and the check valve (98) of the suction side (22) closes and when the pump piston (50) suctions, the check valve (98) of the pressure side closes (20) closes and the check valve (98) on the suction side (22) opens. Door drive (200) according to one of the preceding claims 1 to 12,
characterized,
in that the pump piston (50) delimits a holding space (16) connected to the suction side (22) of the hydraulic pump (10) in the fluid space (12) on its side opposite the pump chamber (14), with a connecting line (60) in the pump piston (50). is arranged with a check valve (98) for a flow of hydraulic fluid (102) from the storage space (16) into the pump space (14) when the pump piston (50) moves in the direction of the storage space (16). Door drive (200) according to claim 14 and claim 5,
characterized,
that the connecting line (60) ends in the receiving area (74) and has a bypass line (60) for the hydraulic fluid (102) to flow past the threaded connection (70) into the receiving area (74) of the pump piston (50) and/or the external thread (80) and/or the internal thread (78) of the threaded connection (70) have a recessed tooth root area (82) and/or a shortened tooth head area (84). Door drive (200) according to claim 14 and claim 6,
characterized,
that the connecting line (60) is arranged in the piston plate (52). Door drive (200) according to one of the preceding claims,
characterized,
in that a check valve (98) is arranged in the first hydraulic connection (92) to prevent a flow of hydraulic fluid (102) from the pressure chamber (214) to the pump chamber (14). Door drive (200) according to one of the preceding claims,
characterized,
in that the hydraulic system (90) has a second hydraulic connection (94) which connects the pressure chamber (214), in particular via a drive piston interior (222), with a spring chamber (216) in which the closer spring (224) is arranged, wherein in the second hydraulic connection (94) has an electrically switchable check valve (300) for selectively releasing or preventing a flow from the pressure chamber (214) into the spring chamber (216) and thereby for moving the drive piston (220) in the closing direction. Door drive (200) according to claim 18,
characterized,
in that at least one throttle valve (100) is arranged in the second hydraulic connection (94) for hydraulic damping of the movement of the drive piston (220) in the closing direction. Door drive (200) according to claim 18 or 19,
characterized,
that the electrically switchable check valve (300) is opened in a de-energized state and releases a flow of hydraulic fluid (102) from the pressure chamber (214) into the second hydraulic connection (94). Door drive (200) according to claim 18 or 19,
characterized,
that the electrically switchable check valve (300) is blocked in a de-energized state and prevents a flow of hydraulic fluid (102) from the pressure chamber (214) into the second hydraulic connection (94). Door drive (200) according to one of the preceding claims 18 to 21,
characterized,
in that the fluid space (12) and the spring space (216) are separated by a plate element (110), in particular a spring plate (112) supporting the closer spring (224), the plate element (110) having a preferably deep-drawn shape relative to the spring space ( 216) has a closed sleeve (114) which extends into the spring space (216) and encloses a sleeve space (116), the sleeve space (116) bordering the fluid space (12) without walls and thereby the fluid space (12) around the sleeve space (116) is enlarged, the seal of the pump piston (50) being arranged against the wall (18) of the fluid space (12) at an end of the pump piston (50) facing the motor unit (30) and located at During operation of the hydraulic pump (10), a section of the pump piston (50) extends at least temporarily into the sleeve space (116). Door drive (200) according to one of the preceding claims 18 to 21,
characterized,
that the fluid space (12) and the spring space (216) adjoin one another without any walls, the seal of the pump piston (50) being arranged against the wall (18) of the fluid space (12) at an end of the pump piston (50) facing the motor unit (30). and during operation of the hydraulic pump (10), a section of the pump piston (50) extends at least temporarily into the spring chamber (216). Door drive (200) according to one of the preceding claims 18 to 22,
characterized,
in that the hydraulic system (90) has a third hydraulic connection (96) which connects the spring chamber (216) with the fluid chamber (12), in particular the pump chamber (14) or the reserve chamber (16), the third hydraulic connection (96). a displacement of the drive piston (220) in the opening direction allows hydraulic fluid (102) to flow from the spring space (216) into the fluid space (12). Door drive (200) according to one of the preceding claims,
characterized,
that the first hydraulic connection (92) and/or the second hydraulic connection (94) and/or the third hydraulic connection (96) is designed at least in sections as a bore, in particular a deep hole, in the housing (210) of the door drive (200). Door drive (200) according to one of the preceding claims,
characterized,
in that the fluid space (12) is delimited on a side facing the electric motor unit (30) by a bearing cover (40), the bearing cover (40) having a bearing (42) in which the drive shaft (32) is axially fixed and radially mounted is, wherein the bearing cover (40) preferably seals the fluid space (12) from the environment. Door drive (200) according to one of the preceding claims,
characterized,
in that the electric motor unit (30) comprises a stepper motor and a planetary gear (38) and/or a cycloid gear (38), wherein preferably the electric motor unit (30) is arranged outside the housing (210) and on the housing (210), in particular on a Housing cover is attached.

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