Door drive and door system

Abstract

A door operator, in particular a swing door operator, comprises an electric motor for providing motor torque, an output shaft suitable for being coupled via a lever or linkage to a door frame or leaf to provide opening torque and to actively move the door from its closed position to its open position and / or to hold it in its open position, and a multi-stage gearbox that couples the electric motor to the output shaft. The gearbox comprises an input stage with an input element for supplying the motor torque, an output stage with an output element that is rotationally fixed to the output shaft, and at least one intermediate gear stage between the input stage and the output stage. The gear stage on the output shaft has a module of 1.5 mm or more and is sintered.

Description

[0001] The invention relates to a door drive, in particular a swing door drive, comprising an electric motor, an output shaft, and a multi-stage gearbox. The invention also relates to a door system, in particular a swing door system, comprising a door with a frame and a leaf pivotably mounted on the frame, and a door drive, wherein the output shaft of the door drive is coupled to the frame or the leaf.

[0002] (Revolving) door operators are designed to actively move a door, especially a revolving door such as a swing door, from its closed position to its open position and to hold it in the open position. For this purpose, such door operators are typically mounted on a fixed component such as the door frame. Their output shaft is connected to a sliding block and a guide rail on one of the door leaves via a linkage or lever. Due to the dimensions of the frame, it is essential that such door operators be as compact as possible. In particular, the door operator should not normally exceed a height of approximately 70 mm. Naturally, door operators should also be as cost-effective as possible.

[0003] The document DE 10 2020 125 098 A1 relates to a method for pivoting a leaf, in particular a door leaf or a window leaf, from a closed position at an opening angle of 0° to an open position at an opening angle greater than 0° and / or from the open position at the opening angle greater than 0° to the closed position at the opening angle of 0° by means of a leaf torque, wherein the leaf torque comprises a manual torque, in particular generated by a person, and a drive torque, wherein the drive torque is generated by means of a drive device with a drive module, a closer module and a control module, wherein the drive module comprises an electrical machine comprising one, in particular a single, stator and one, in particular a single, rotor, wherein the closer module has an energy storage device, in particular a mechanical one,wherein the control module comprises a control device, wherein the drive torque includes a machine torque generated directly or indirectly by the electric machine and a closing torque generated by the closing module. The machine torque is greater than 0 Nm when at least one of the opening angles is greater than 0°.

[0004] The document DE 10 2015 202 852 B3 relates to a door drive, in particular a revolving door drive, comprising a housing, an output shaft that can be coupled to a door leaf or a frame, a motor for driving the output shaft, and a spring unit that is tensioned during a respective opening movement of the door leaf and released during a respective closing movement of the door leaf. The output shaft can be driven by the motor via a rack that can be actuated by a spur-bevel gearing system that comprises a helical spur gear section on the motor side, a straight-toothed spur gear section on the rack side, and a bevel gear section arranged therebetween, in particular provided with Gleason gearing.

[0005] The publication DE 10 2019 200 656 A1 relates to a drive for a revolving door, comprising a geared motor with an electric drive unit and a gear unit. The electric drive unit comprises a brushless DC motor. The gear unit is multi-stage and equipped with an angular gear and spur gear stages.

[0006] It is therefore an object of the present invention to provide a door drive that is compact and inexpensive to manufacture.

[0007] This problem is solved by the subject matter of the independent claims. Advantageous further developments are the subject matter of the dependent claims and emerge from the description and the drawings.

[0008] The door drive according to a first and second aspect of the present invention can, in particular, be a revolving door drive and comprises an electric motor for providing a motor torque, an output shaft suitable for being coupled to a frame or a leaf of a door via a lever or a linkage to provide an opening torque and actively move the door from its closed position to its open position and / or to hold it in its open position, and a multi-stage gearbox that couples the electric motor to the output shaft. The gearbox has an input stage with an input element for feeding the motor torque, an output stage with an output element that is rotationally fixedly connected to the output shaft, and at least one gear intermediate stage between the input stage and the output stage. The output element is sintered and has a modulus of 1.5 mm or more.

[0009] The output element is the gear stage on the output shaft.

[0010] Additional gear stages can also be sintered.

[0011] The module of the gear stage on the output shaft (module of the output element) can optionally be 1.75 mm to 3.25 mm, preferably 2 mm to 3 mm, in particular 2.5 mm.

[0012] The module is a measure, familiar to those skilled in the art, of the size of the teeth of a gear and is given in millimeters. The module m corresponds to the pitch circle diameter d of the gear divided by the number z of teeth on the gear: m=dz

[0013] The module is therefore an important parameter for the design of gears. Depending on the load to which the gears are subjected, the module must be selected accordingly so that the teeth are large enough to bear the load.

[0014] Preferably, the output gear and the gears of the intermediate gear stage(s) are sintered, particularly for cost reasons, as this allows for cost savings of over 50% compared to machined gears. Due to the output gear's module of 1.6 mm or more, it is possible to compensate for the typically lower strength of the sintered material, such as sintered steel, so that the gears offer significant cost savings while still exhibiting strength equivalent to machined gears.

[0015] Typically, the speed and torque are changed within a transmission stage, although this is not always necessary. Transmission stages can be designed, for example, as gear stages or belt stages. Within the scope of the present invention, the input stage is the transmission stage that includes the input element through which the motor torque is supplied. The output stage is the transmission stage that includes the output element to which the output shaft is rotationally fixed and, in particular, coaxially connected. The intermediate gear stage(s) connect(s) the input stage and the output stage.

[0016] The output shaft is typically coupled to a door frame or leaf via a lever or linkage. The lever may have a sliding block at its end, which is guided in a slide rail attached to the frame or leaf. The linkage may be, in particular, a scissor linkage, the end of which is attached to the frame or leaf.

[0017] In the first aspect, the gear(s) of the intermediate gear stage each have a mounting bore for a ball bearing to support the respective gear on a journal of the gearbox housing. The ball bearing can be fitted into the mounting bore with its outer ring, holding the gear in position. Instead of a protruding bearing journal, a mounting bore is used, which can be easily manufactured by sintering and also results in a compact design.

[0018] In the second aspect, the input stage has a pulley with a recess, in particular annular, wherein a pinion of the subsequent intermediate gear stage is fixedly arranged on the pulley, and wherein a bearing section of a gearbox housing extends into the recess and accommodates a ball bearing for the pinion in order to mount the pinion and the pulley to the housing. The pulley and pinion can be fixedly connected to each other, for example, by a bolt, a key, a splined shaft, or by similar known means.

[0019] In a preferred configuration, the electric motor is a brushless DC motor, also known as a BLDC motor. BLDC motors can be relatively short and flat, which positively impacts the compactness of the door drive. Due to its compact design, the BLDC motor can be installed with its output shaft running perpendicular to the gearbox. At the same time, BLDC motors are comparatively lightweight for the same power output, especially compared to other DC motors.

[0020] The BLDC motor has a rated speed of approximately 3700-5600 revolutions per minute. Other DC motors have comparable rated speeds of 1500-2500 revolutions per minute. To achieve the same speed at the output shaft, the overall gear ratio is approximately 500-600 instead of 250-300.

[0021] Preferably, the electric motor has an output shaft that is non-rotatably connected to the input element for transmitting the motor torque to the input element. The input stage further comprises a driven gear driven by the input element, and the axis of the output shaft runs parallel to the rotational axis of the driven gear. In particular, the input stage can be designed as a belt stage. This configuration enables higher transmission efficiency compared to solutions in which the axis of the output shaft runs transversely to the rotational axis of the driven gear. For example, the efficiency loss is approximately 30% if the input stage is a helical gear stage or worm gear stage, whereas only approximately 5% efficiency is lost with spur gear or belt gear stages.

[0022] The gearbox can have at least four, in particular exactly four, gear stages. Previously known door drives typically have three gear stages. A four-stage gearbox can reduce higher rated speeds of the electric motor and achieve a higher torque at the output element. The use of a BLDC motor, for example, can result in a higher rated speed compared to other DC motors. For example, the rated speed can be in the range of approximately 3,700 rpm. -1 up to 5,600 rpm -1 To achieve a comparable door opening time, a higher gear ratio and thus a fourth gear stage is desirable.

[0023] The gear(s) of the intermediate gear stage can be formed as a single unit with the pinion of the subsequent gear stage. Such combined gear elements are well suited for sintering. Furthermore, the one-piece design eliminates the need for additional connecting elements such as keys or joining processes, which is also advantageous for achieving good strength.

[0024] In a preferred embodiment of the second aspect, the gear wheel of the intermediate gear stage or the gear wheels of the intermediate gear stages each have a receiving bore for a ball bearing for supporting the respective gear wheel on a journal of a transmission housing. The ball bearing can be fitted into the receiving bore with its outer ring and hold the gear wheel in position. Instead of a protruding bearing journal, a receiving bore is used, which can be easily manufactured by sintering and also results in a compact design.

[0025] In a preferred embodiment of the first aspect, the input stage has a pulley with a recess, in particular annular, wherein a pinion of the subsequent intermediate gear stage is arranged non-rotatably on the pulley, and wherein a bearing section of a housing of the transmission extends into the recess and accommodates a ball bearing for the pinion in order to support the pinion and the pulley on the housing. The pulley and pinion can be non-rotatably connected to each other, for example, by a bolt, a key, a splined shaft, or by similar known means.

[0026] Preferably, the output stage is designed as a gear stage. This contributes to high efficiency and good, cost-effective manufacturability.

[0027] A return element can be provided that is connected to the output element in a rotationally fixed manner, in particular one that is formed integrally therewith, and is designed to interact with a mechanical energy store to bring about an automatic movement of the door into the closed position when the motor torque is lost. The mechanical energy store can in particular be a spring that is tensioned when the door is opened. If the motor torque is lost, for example in the event of a power failure, the tensioned spring causes the door to close. The return element preferably has a heart-shaped cam disc on which a pressure roller of the door drive, coupled to the mechanical energy store, rolls.

[0028] In a preferred embodiment, the output shaft includes internal teeth, in particular internal splined teeth, for engaging a corresponding toothing of a lever or linkage of the door drive. This ensures that the rotation of the output element results in an opening movement of the door leaf.

[0029] The invention also relates to a door system, in particular a revolving door system, comprising a door with a frame and a leaf pivotably mounted on the frame, as well as the door drive described above. The output shaft is coupled to the frame or the leaf.

[0030] The invention is explained below only by way of example with reference to the schematic drawings. These drawings show Fig. 1 a perspective view of a door drive according to an exemplary embodiment, Fig. 2 a perspective view of the door drive mechanism Fig. 1, Fig. 3 another perspective view of the door drive mechanism Fig. 1, Fig. 4 a sectional view of the door drive Fig. 1 corresponding to the section plane IV, Fig. 5 a sectional view of the door drive Fig. 1 according to the cutting plane V and Fig. 6 a sectional view of the door drive Fig. 1 corresponding to section plane VI.

[0031] Fig. Figure 1 shows a perspective view of a door drive 10, with the housing of the door drive 10 hidden. The door drive 10 has an electric motor 11, which in the present embodiment is designed as a brushless DC motor, also known as a BLDC motor.

[0032] Preferably, a BLDC external rotor motor is used, whose motor shaft is arranged parallel to the shaft of the output stage. The external rotor is equipped with ferrite magnets, unlike internal rotors, which are often built with expensive and stronger neodymium magnets. The larger effective radius of the external rotor partially compensates for its lower magnetic force.

[0033] In addition, the door drive 10 has an output shaft 67 with an internal toothing 61, namely an internal spline. The internal toothing 61 serves to engage a lever or rod (not shown) with a corresponding external toothing. The output shaft 67, coupled to a frame or leaf of a door via the lever or rod, provides an opening torque to actively move the door from its closed position to its open position and / or to hold it in its open position.

[0034] The door drive 10 also includes a gearbox 13. The gearbox 13 is connected between the electric motor 11 and the output shaft 67, so that motor torque supplied to the gearbox 13 by the electric motor 11 causes the output shaft 67, and thus the lever or linkage, to rotate via the gearbox stages. The electric motor 11, the gearbox 13, and the output shaft 67 are housed in a casing 15, which is composed of two casing parts 15a and 15b (see Figure 1). Fig. 4 to 6), which are connected to each other by means of connecting elements such as screws, pins or bolts.

[0035] How Fig. 2 and Fig. As shown in Figure 3, the transmission 13 in the present embodiment has four gear stages, namely an input stage 17, an output stage 21 and two intermediate gear stages 25, 27. Usually, each stage serves to change the speed and the torque.

[0036] The input stage 17 is designed as a belt stage and comprises a driven pulley 31 and an input element 19 in the form of a smaller, driving pulley, which can be engaged with an output shaft (not shown) of the electric motor 11 to transmit the motor torque to the input element 19. A toothed belt 29 is engaged with the input element 19 and the pulley 31, so that the pulley 31 is driven by the input element 19 via the belt 29.

[0037] The pulley 31 is, as can be seen from Fig. 2 and Fig. As can be seen in Figure 6, the gear 33 is non-rotatably connected to a gear 33, which is meshed with another gear 35. The gear 33 and the gear 35 together form the first intermediate gear stage 25, with the gear 33 functioning as a pinion and the gear 35 as a wheel. In this example, the intermediate gear stage 25 is designed as a spur gear stage. In other embodiments, it is also conceivable that the intermediate gear stage 25 has helical teeth.

[0038] The gear 35 is, as seen from Fig. 2 and Fig. As can be seen in Figure 5, the combination gear element is formed in one piece with a gear 37, wherein the gear 37 functions as the pinion of the subsequent gear stage, namely the second intermediate gear stage 27. The gear 37 is in mesh with a gear 39, which functions as the gear of the intermediate gear stage 27.

[0039] The gear 39 is, as seen from Fig. 2 and Fig. As can be seen in Figure 4, the gear element is formed in one piece with a gear 41, the gear 41 functioning as the pinion of the subsequent gear stage, namely the output stage 21. The gear 41 is in mesh with a gear 43, which functions as the gear and output element 23 of the output stage 21. The output stage 21 is also designed as a spur gear stage.

[0040] The output element 23 of the output stage 21 is connected in a rotationally fixed manner to the output shaft 67. Due to the torque transmission to the output element 23, the output shaft 67 is thus set in rotation.

[0041] Formed in one piece with the starting element 23, it is in Fig. 2. The return element 59 comprises a heart-shaped cam disk, on which a pressure roller of the door drive 10 rolls, coupled to a mechanical energy storage device (also not shown). The mechanical energy storage device can, in particular, be a spring that is tensioned when the door is opened by means of the electric motor 11 and the gear 13. If the motor torque subsequently ceases, for example due to a power failure, the spring relaxes, so that the pressure roller exerts pressure on the cam disk and rotates the output shaft 67 back against the opening direction. The door then moves automatically into its closed position.

[0042] The gears 33, 35, 37, 39, 41, 43 of the intermediate gear stages 25, 27 and the output stage 21 are sintered. In the present embodiment, the gears 41, 43 of the output stage 21 have a modulus m of approximately 1.5 mm to 3 mm to compensate for the somewhat lower strength of the sintered steel compared to machined steel gears and to achieve the required service life.

[0043] In order to be able to sinter the wheel 39 of the gear intermediate stage 27 with the pinion 41 of the output stage 21 as one part, the combination gear element is provided with no bearing journal on the side of the wheel 39, but rather a receiving bore 47 for a ball bearing 49, as Fig. Figure 4 shows this. This also facilitates manufacturing by sintering. The ball bearing 49 holds the wheel 39 in position with its outer ring, while a pin 53 of the housing part 15b engages in the ball bearing bore and receives the inner ring of the ball bearing 49. This allows the dimensions of the door drive 10 to be kept correspondingly compact. The situation is similar as follows: Fig. Figure 5 shows the gear 35 of the intermediate gear stage 25, which has a receiving bore 45 for a ball bearing 49. The ball bearing 49 holds the gear 35 in position with its outer ring, while a pin 51 of the housing part 15a engages in the ball bearing bore and receives the inner ring of the ball bearing 49. Another ball bearing 49 is in contact with an outer bearing journal 63 of the pinion 37 with its inner ring. The outer ring of this ball bearing 49 is received in the housing part 15b.

[0044] How Fig. 2, Fig. 5 and Fig.As shown in Figure 6, the pulley 31 has an annular recess 55. A bearing section 57 of the housing part 15a extends into the recess 55 and accommodates a ball bearing 49 for the pinion 33 of the intermediate gear stage 25, in order to support the pinion 33 and the pulley 31 on the housing 15. Another ball bearing 49 is in contact with an outer bearing journal 65 of the pinion 33 via its inner ring.

[0045] The illustrated embodiment corresponds to a door drive 10, which is inexpensive to manufacture due to the use of sintered gears, yet whose gears also exhibit sufficient strength. Furthermore, the door drive 10 is extremely compact and lightweight due to the use of the BLDC motor 11 and the design of the gears and the housing 15. Finally, the belt drive, in particular, ensures a significantly higher efficiency instead of a worm gear drive.

[0046] The output element 23 has, in addition to the two bearing points, three functional areas: the gear 43, the heart curve of the return element 59, and the internal toothing 61. Ideally, the three functional areas are manufactured in one sintering process, which significantly reduces costs.

[0047] If the output element 23 were machined from a solid block, the gear 43 would have to be milled, the return element 59 milled, and the internal teeth 61 broached. Due to the large amount of material removed, the output element would then be very expensive.

[0048] Even if the return element 59 had to be milled and the internal toothing 61 had to be cleared in the sintered starting element 23, the chip volume and costs would be significantly smaller than in machining from a solid block. List of reference symbols 10 Door drive 11 Electric motor 13 gearboxes 15 cases 15a Housing part 15b Housing part 17 Entry level 19 Entrance element 21 Output stage 23 Starting element 25 Gear intermediate stage 27 Intermediate gear stage 29 belts 31 Pulley 33 gear 35 gear 37 gear 39 gear 41 gear 43 gear 45 Mounting hole 47 Intake bore 49 ball bearings 51 cones 53 cones 55 Exclusion 57 Storage section 59 Reset element 61 Internal teeth 63 bearing journals 65 bearing journals 67 Output shaft

Claims

[1] Door drive (10), in particular revolving door drive, which an electric motor (11) for providing a motor torque, an output shaft (67) which is suitable for being coupled to a frame or a leaf of a door via a lever or a linkage in order to provide an opening torque and to actively move the door from its closed position to its open position and / or to hold it in its open position, and a multi-stage gearbox (13) which couples the electric motor (11) to the output shaft (67), wherein the transmission (13) has an input stage (17) with an input element (19) for feeding the engine torque, an output stage (21) with an output element (23) which is connected in a rotationally fixed manner to the output shaft (67), and at least one gear intermediate stage (25, 27) between the input stage (17) and the output stage (21), wherein the output element (23) is sintered and has a module of 1.5 mm or more, and wherein the wheel (35, 39) of the gear intermediate stage (25, 27) or the wheels (35, 39) of the gear intermediate stages (25, 27) each have a receiving bore (45, 47) for a ball bearing (49) for mounting the respective wheel (35, 39) on a pin (51, 53) of a housing (15) of the transmission (13). [2] Door drive (10) according to claim 1, characterized bythat the output element (23) is fully sintered with a gear (43), a return element (59) and an internal toothing (61), or that the return element (59) is milled and the internal toothing (61) is cleared. [3] Door drive (10) according to claim 1 or 2, characterized by that the module of the output element (23) is 1.5 mm to 3.25 mm, preferably 2 mm to 3 mm, in particular 2.5 mm. [4] Door drive (10) according to one of the preceding claims, characterized by that the electric motor (11) is a brushless DC motor, preferably an external rotor motor, whose drive shaft is parallel to the output shaft (67). [5] Door drive (10) according to one of the preceding claims, characterized by that the input stage (17) is designed as a toothed belt stage. [6] Door drive (10) according to one of the preceding claims, characterized bythat the transmission (13) has at least four, in particular exactly four, transmission stages (17, 21, 25, 27). [7] Door drive (10) according to one of the preceding claims, characterized by that the wheel (35, 39) of the gear intermediate stage (25, 27) or the wheels (35, 39) of the gear intermediate stages (25, 27) is or are formed as a combination gear element in one piece with the pinion (37, 41) of the respective subsequent gear stage (21, 27). [8] Door drive (10), in particular revolving door drive, which an electric motor (11) for providing a motor torque, an output shaft (67) which is suitable for being coupled to a frame or a leaf of a door via a lever or a linkage in order to provide an opening torque and to actively move the door from its closed position to its open position and / or to hold it in its open position, and a multi-stage transmission (13) which couples the electric motor (11) to the output shaft (67), wherein the transmission (13) has an input stage (17) with an input element (19) for feeding the engine torque, an output stage (21) with an output element (23) which is connected in a rotationally fixed manner to the output shaft (67), and at least one gear intermediate stage (25, 27) between the input stage (17) and the output stage (21), wherein the output element (23) is sintered and has a module of 1.5 mm or more, wherein the input stage (17) has a belt wheel (31) with a particularly annular recess (55), wherein a pinion (33) of the subsequent gear intermediate stage (25) is arranged in a rotationally fixed manner on the belt wheel (31), and wherein a bearing section (57) of a housing (15) of the transmission (13) dips into the recess (55) and accommodates a ball bearing (49) for the pinion (33) in order to mount the pinion (33) and the belt wheel (31) on the housing (15). [9] Door drive (10) according to one of the preceding claims, characterized by that the output stage (21) is designed as a gear stage. [10] Door drive (10) according to one of the preceding claims, characterized bythat a return element (59) is provided which is connected to the output element (23) in a rotationally fixed manner and, in particular, is formed in one piece therewith and is designed to cooperate with a mechanical energy store in order to bring about an automatic movement of the door into the closed position when the motor torque ceases. [11] Door drive (10) according to claim 10, characterized by that the return element (59) has a heart-shaped cam disc on which a pressure roller of the door drive (10) coupled to the mechanical energy storage device rolls. [12] Door drive (10) according to one of the preceding claims, characterized by that the output shaft (67) has an internal toothing (61), in particular an internal serration, for engaging a corresponding toothing of a lever or a linkage of the door drive (10). [13] Door system, in particular a revolving door system, comprising a door with a frame and a leaf pivotably mounted on the frame and a door drive (10) according to one of the preceding claims, wherein the output shaft (67) is coupled to the frame or the leaf.

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