Cycloidal gearbox with two transmission stages, drive unit, method for operating the drive unit and gripping or clamping device with such a gearbox

Abstract

The invention relates to a gearbox (16), in particular for use in electronic gripping or clamping directions, a drive unit (10) and electronic gripping or clamping devices (120), wherein the gearbox comprises a drive shaft (24), an eccentric (28), a first internal gear (30), a first external gear (38), a second internal gear (32), a second external gear (40), a first output element (46), a second output element (48) and an output shaft (58).

Description

[0001] The invention relates to a gearbox, in particular for use in electronic gripping or clamping devices, a drive unit, a method for operating the drive unit and an electronic gripping or clamping device.

[0002] Electronic gripping or clamping devices have several movable gripping or clamping elements that can clamp the component to be fixed. An electric motor is used to drive the gripping or clamping elements, and its power output corresponds to the product of its rotational speed and torque. To generate the forces necessary for gripping or clamping the components, the torque provided by the electric motor is increased in a gearbox. As a result, due to the inversely proportional relationship, the rotational speed and thus the travel speed of the gripping or clamping elements decreases. Consequently, gripping or clamping components that require a long travel distance of the gripping or clamping elements is very time-consuming. In particular, changing between components with a large diameter and those with a small diameter is inefficient.

[0003] Cycloidal gear units with two gear stages are known from EP 3 301 323 and EP 3 301 324. JP H05 39 235 Y2 discloses a reduction gear unit. US 4 807 494 A discloses a planetary gear unit with a stepwise adjustable gear ratio. CN 102 787 469 A discloses a fully automatic delay clutch for washing machines.

[0004] The invention is based on the objective of providing a gearbox, a drive unit and an electronic gripping or clamping device that enables efficient gripping or clamping of components, in particular with different diameters.

[0005] This problem is solved by a transmission according to claim 1. Further developments of the transmission are the subject of claims 2 to 11. The problem is further solved by a drive unit according to claims 12 to 14. The problem is further solved by a method for operating a drive unit according to the invention according to claim 15. The problem is further solved by an electronic gripping or clamping device according to claim 16.

[0006] The transmission comprises a drive shaft, an eccentric, a first inner gear, and a first outer gear. The first inner gear and the first outer gear each have several teeth, which are arranged in a uniform distribution along their respective outer and inner circumferences. The teeth of the first inner and outer gears are rounded and have arcuate flanks. The teeth of the first inner gear are designed as cams, and the teeth of the first outer gear are designed as rollers. The transmission also includes a first output element and an output shaft, which provides an interface to subsequent assemblies, such as a clamping unit with gripping or clamping elements. The drive shaft and the output shaft are arranged coaxially with each other along a longitudinal axis of the transmission.

[0007] The drive shaft and the eccentric are connected to each other in a rotationally fixed and preferably also a displacement-fixed manner. It is possible for the drive shaft and the eccentric to be supplied separately and, in particular, connected to each other in a rotationally fixed manner by means of a positive-locking connection, preferably by means of polygonal surfaces. This enables a modular design of the gearbox and ensures reliable torque transmission. Alternatively, it is possible for the drive shaft and the eccentric to be formed in one piece. This reduces assembly effort. The eccentric has an eccentric center located on an eccentric plane that runs orthogonally to the longitudinal axis of the gearbox. The eccentric center is spaced from the longitudinal axis of the gearbox by an eccentricity measure.

[0008] The first inner gear has at least one largely centrally arranged, preferably circular, main recess. The eccentric is arranged in the main recess of the first inner gear, wherein the eccentric and the first inner gear are rotatable relative to each other. It is preferred if a rotary bearing, in particular a plain bearing, a ball bearing, or a needle bearing, is arranged between the main recess and the eccentric. In this way, the frictional forces acting between the eccentric and the first inner gear can be reduced.

[0009] The first inner gear and the first outer gear have a different number of teeth. The first inner gear rolls against the first outer gear, performing an elliptical (cycloidal) motion around the longitudinal axis of the gear.

[0010] The first inner gear has several secondary recesses, in particular circular ones. The secondary recesses are arranged around the main recess, in particular at equal angular intervals to each other on a circular line concentric with the main recess.

[0011] The first output element has several drive pins that have a smaller diameter than the secondary recesses of the first inner gear. Preferably, the diameter of the drive pins is smaller than the diameter of the secondary recesses of the first inner gear by at least approximately twice the eccentricity of the eccentric. The drive pins are arranged so that they engage correspondingly in the secondary recesses of the first inner gear. It is possible that wear-optimized and / or friction-optimized materials and / or surface structures, in particular plain bearings, are provided on the circumferential surfaces of the drive pins.

[0012] The gear ratio i1 of this gear is determined according to the following formula, where z1 is the number of teeth of the first outer gear and z2 is the number of teeth of the first inner gear: i1=z2 / (z1−z2)

[0013] In particular, the number of teeth of the first outer gear z1 is 1 greater than the number of teeth of the first inner gear z2. In this case, the number of teeth of the first inner gear z2 determines the gear ratio of this gear.

[0014] According to the invention, the transmission comprises a second inner gear comprising teeth. The first inner gear and the second inner gear are connected to each other in a rotationally fixed manner. Furthermore, the transmission comprises a second outer gear comprising teeth. The teeth of the second inner and the second outer gear are, in particular, rounded and have arcuate flanks. The teeth of the second inner gear are, in particular, designed as cams, and the teeth of the second outer gear are, in particular, designed as rollers. The second inner gear rolls within the second outer gear and drives it. The transmission also comprises a second output element, which is connected to the second outer gear in a rotationally fixed manner.

[0015] A gear ratio i2 of this gear is determined according to the following formula, where z1 is the number of teeth of the first outer gear, z2 is the number of teeth of the first inner gear, z3 is the number of teeth of the second inner gear and z4 is the number of teeth of the second outer gear: i2=1 / (1−(z1*z3 / z2*z4))

[0016] Specifically, the number of teeth of the first outer gear z1 is 1 greater than the number of teeth of the first inner gear z2, the number of teeth of the second outer gear z4 is 1 greater than the number of teeth of the second inner gear z3, and the difference between the number of teeth of the first outer gear z1 and the number of teeth of the second outer gear z4 is equal to 1. In this case, the gear ratio is the product of the number of teeth of the first inner gear z2 and the number of teeth of the second outer gear z4.

[0017] Furthermore, the transmission includes a switching device that can be selectively engaged with either the first or the second output element. The switching device is also engaged with the output shaft. Thus, the switching device enables selectable torque transmission from either the first or the second output element to the output shaft. The two output elements have different speeds and torques, with the product of speed and torque being at least approximately the same for both output elements. By actuating the switching device, it is possible to switch between the two output elements, i.e., the two gears of the transmission: a rapid traverse and a standard gear. Preferably, the rapid traverse is achieved via a rotary coupling of the first output element, and the standard gear via a rotary coupling of the second output element to the output shaft.

[0018] The gearbox and / or the switching device are designed such that, in the unactuated state of the switching device, the power gear, i.e., a low rotational speed or travel speed, is selected. This prevents accidental activation of the rapid traverse and damage to the gearbox and / or the gripping or clamping device and / or the component to be gripped or clamped. Preferably, the gearbox is self-locking in power gear. Therefore, a force and / or torque acting on the output shaft cannot rotate the gearbox due to the high gear ratio. This ensures that any gripping and / or clamping force already applied is maintained by the gearbox even if the electric motor used for gripping and / or clamping is switched off or fails. The electric motor thus does not need to continuously apply torque to generate the necessary gripping or clamping force.Similarly, in the case of manual generation of the torque required for gripping and / or clamping, for example by a crank, the torque does not have to be applied continuously.

[0019] In a preferred embodiment, it is provided that that the second inner gear and the second outer gear have a different number of teeth z3 and z4 respectively, and that the difference in the number of teeth of the first inner gear z2 and the first outer gear z1, as well as the difference in the number of teeth of the second inner gear z3 and the second outer gear z4, are equal. This ensures reliable operation of the gearbox.

[0020] Furthermore, it is preferably provided that the first inner gear and the second inner gear have a different number of teeth z2 and z3, respectively. This enables particularly reliable operation of the gearbox.

[0021] It is preferred that the first and second inner gears are connected to each other in a way that prevents displacement. This ensures the reliable operation of the gearbox. It is particularly preferred that the first and second inner gears are formed in one piece. This reduces assembly effort.

[0022] In a preferred embodiment, the second outer gear and the second output element are connected to each other in a way that prevents displacement. This increases the operational reliability of the gearbox. It is particularly preferred that the second outer gear and the second output element are formed in one piece. This reduces assembly effort.

[0023] Furthermore, it is preferred that the shifting device includes a clutch element that can be displaced along the longitudinal axis of the transmission. This allows a shifting operation to be carried out in a simple manner.

[0024] Furthermore, it is advantageous that the coupling element is rotationally fixed to at least one positive-locking element and that either the first or the second output element engages positively with the positive-locking element. This ensures reliable operation of the gearbox.

[0025] It is further preferred that the first output element engages radially in recesses of the positive locking element, or that the second output element engages axially in recesses of the positive locking element. It is particularly preferred that teeth arranged on an end face of the second output element can engage in recesses of the positive locking element. This also contributes to reliable operation of the gearbox.

[0026] It is particularly preferred that the switching device comprises at least one displacement device which can move the clutch element along the longitudinal axis of the transmission. This allows a switching operation to be carried out in a simple manner.

[0027] Furthermore, it is preferred that the displacement device includes a controllable displacement element. Alternatively or additionally, it is preferred that the displacement device includes a return element. This enables reliable operation of the transmission, particularly during shifting operations.

[0028] Furthermore, it is advantageous that the displacement element comprises at least one pneumatic cylinder and / or hydraulic cylinder and / or lifting magnets and / or handling element and / or a motor-spindle unit and / or rotary unit with guide ramps and / or rotary unit with guide cams. This allows for simple displacement of the coupling element.

[0029] In a preferred embodiment, the displacement element comprises several pneumatic cylinders and / or hydraulic cylinders and / or lifting magnets and / or handling elements, which are arranged, in particular, at equal intervals from one another on a circular line concentric to the longitudinal axis of the transmission. This further improves the displacement of the coupling element.

[0030] It is particularly preferred that the first outer gear is connected to the gearbox housing in a rotationally fixed and, in particular, also displacement-resistant manner. This also contributes to the reliable operation of the gearbox.

[0031] Furthermore, it is preferred that the drive shaft and the eccentric are positively connected to each other, in particular via polygonal surfaces. This enables a modular design of the gearbox and ensures reliable torque transmission.

[0032] The problem underlying the invention, mentioned at the outset, is further solved by a drive unit according to claim 12. The drive unit comprises a gearbox according to the invention, a control unit, and an electric motor. An output shaft of the electric motor is rotationally fixed to the drive shaft and / or formed integrally with the drive shaft. This enables reliable torque transmission and a compact design of the drive unit.

[0033] It is advantageous that the control device is configured to engage the switching device with either the first output element or the second output element, depending on at least one controlled variable. This enables efficient operation of the gearbox.

[0034] In a preferred embodiment, the at least one controlled variable comprises a sensor signal and / or a length measurement and / or a diameter measurement and / or a distance measurement and / or a weight measurement and / or a position measurement and / or a load measurement and / or an external input value, in particular of a component to be gripped or clamped when used in electronic gripping or clamping devices. Preferably, the sensor signal comprises signals from a distance sensor and / or a load sensor and / or a voltage sensor and / or a current sensor and / or a speed sensor. More preferably, the distance measurement comprises, in particular, the distance between one or more gripping or clamping elements and a component to be gripped or clamped. This enables efficient and reliable operation of the gearbox.

[0035] The problem underlying the invention, mentioned at the outset, is further solved by a method for operating a drive unit according to the invention as described in claim 15. For large distances, the switching device engages with the first output element, and / or for large weights or loads, the switching device engages with the second output element. Advantageously, when there is a large distance between the component to be gripped or clamped and the gripping or clamping elements, the coupling element engages with the first output element, whereas when there is a small distance between the component to be gripped or clamped and the gripping or clamping elements, the coupling element engages with the second output element. This enables reliable operation of the gearbox and particularly efficient execution of clamping operations.

[0036] An advantage is that the gearbox and the electric motor are arranged in a single housing in such a way that the housing largely encloses both components. This contributes to a compact design of the drive unit and protects it from environmental influences.

[0037] The problem underlying the invention, mentioned at the outset, is further solved by an electronic gripping or clamping device according to claim 16. This device comprises a drive unit according to the invention and at least two gripping elements for gripping and / or at least two clamping elements for clamping a component. In particular, the electronic gripping or clamping device comprises at least one connection device that connects the gripping and / or clamping elements to the output shaft, for example, an auxiliary gearbox and / or a threaded spindle. This enables efficient and reliable handling of the component.

[0038] Further features and advantages of the invention are the subject of the following description of preferred embodiments.

[0039] The drawing shows: Fig. 1 an exploded view of a drive unit according to the invention with a gearbox according to the invention from a first viewing direction; Fig. 2. An exploded view showing the drive unit according to Fig. 1 from a second perspective; Fig. 3 a representation of a gear diagram of the gearbox of the drive unit according to Fig. 1; Fig. 4 a longitudinal section of the drive unit according to Fig. 1; Fig. 5 a representation of the gear scheme according to Fig. 3 in a first switching state; Fig. 6 a longitudinal section of the drive unit according to Fig. 4 in a first switching state; Fig. 7 a representation of the gear scheme according to Fig. 3 in a second switching state; Fig. 8 a longitudinal section of the drive unit according to Fig. 4 in a second switching state; and Fig. 9 a schematic representation of an electronic gripping or clamping device according to the invention.

[0040] The Fig. Figure 1 shows a drive unit 10, particularly for use in electronic gripping or clamping devices, in an exploded view from a first perspective. Fig. 2 shows the drive unit 10 after Fig. 1. From a second perspective. Fig. Figure 3 shows the gear diagram of gearbox 16 of drive unit 10. Fig. 1. The Fig. Figure 4 shows a corresponding longitudinal section of the drive unit 10. Fig. 1.

[0041] The drive unit 10 extends along a longitudinal axis 12 of the transmission and comprises an electric motor 14 and a gearbox 16, which also extend along the longitudinal axis 12 of the transmission. Furthermore, the drive unit 10 comprises a motor shield 17 with cable guide elements 19, a control unit 18, and a housing 20 in which at least the electric motor 14 and, in particular, the control unit 18 are arranged.

[0042] The control unit 18 is configured to supply and control the electric motor 14 with externally provided electrical energy. The externally provided energy can be supplied, in particular, by a power grid and / or an accumulator and / or a battery and / or a fuel cell. The electric motor 14 is configured to convert the electrical energy into a rotational movement and to introduce it, at least indirectly, into the gearbox 16. The gearbox 16 is configured to adapt and / or transform the movement and to make it available to at least one assembly (not shown), for example, a gripping or clamping unit with gripping or clamping elements.

[0043] How Fig. Figure 4 shows that the electric motor 14 includes an output shaft 22 which extends along the longitudinal axis 12 of the transmission.

[0044] The gearbox 16 comprises a drive shaft 24 extending along the longitudinal axis 12 of the gearbox and preferably formed integrally with the output shaft 22 of the electric motor 14, i.e., the output shaft 22 of the electric motor 14 is simultaneously the drive shaft 24 of the gearbox 16. The gearbox 16 comprises a coupling element 26 having polygonal surfaces 86 and an eccentric 28.

[0045] The drive shaft 24 is connected to the coupling element 26 in a rotationally fixed and, in particular, also a displacement-fixed manner along the longitudinal axis 12 of the transmission, especially via a press fit 84. The coupling element 26 is positively connected to the eccentric 28 via the polygonal surfaces 86, 88 and thus rotationally fixed. The eccentric 28 is radially supported on its inner side, especially via a needle bearing 27 comprising needles 25.

[0046] As the Fig. As shown in Figure 1, the eccentric 28 has an eccentric center 21 lying on an eccentric plane 15 that is orthogonal to the longitudinal axis 12 of the transmission. The eccentric center 21 of the eccentric 28 is, by definition, eccentric, i.e., not concentric, but rather spaced a distance 23 from the longitudinal axis 12 of the transmission. The longitudinal axis 12 of the transmission therefore does not pass through the eccentric center 21. Consequently, an outer circumferential surface of the eccentric 28 is not concentric with the longitudinal axis 12 of the transmission.

[0047] As the Fig. 1, Fig. 2 and Fig. As shown in Figure 4, the eccentric 28 has a ring collar 29 that protrudes radially on the outside of the eccentric 28.

[0048] Furthermore, the transmission 16 comprises a first internal gear 30 and a second internal gear 32, which are preferably formed in one piece. The first internal gear 30 and the second internal gear 32 each comprise teeth 34 and 36, which are preferably arranged evenly distributed along their respective outer circumferences. Preferably, the number of teeth 36 of the second internal gear 32 differs from the number of teeth 34 of the first internal gear 30. The teeth 34 of the first internal gear 30 and the teeth 36 of the second internal gear 32 are preferably rounded with arcuate flanks and are particularly designed as cams. The first internal gear 30 comprises a largely centrally arranged, preferably circular, main recess 31 in which the eccentric 28 is arranged. In particular, the outer circumferential surface of the eccentric 28 is at least partially arranged within the main recess 31.

[0049] The eccentric 28 and the main recess 31 are rotatable relative to each other. How Fig. As shown in Figure 4, a rotary bearing 90 is provided to reduce friction between the eccentric 28 and the main recess 31. This bearing comprises an inner bearing ring 92 and an outer bearing ring 94. The inner bearing ring 92 is rotationally fixed to the eccentric 28 in a joining section 93, in particular by press-fitting, and is axially supported by the ring flange 29. The outer bearing ring 94 is fixed in the main recess 31 in a joining section 95, in particular by press-fitting.

[0050] As the Fig. 1 and Fig. As shown in Figure 4, the first internal gear 30 comprises several, in particular circular, secondary recesses 33 which are arranged around the main recess 31, in particular at equal angular intervals to each other on a circular line concentric to the main recess.

[0051] The transmission 16 further comprises a first outer gear 38 and a second outer gear 40. The first outer gear 38 and the second outer gear 40 each have teeth 42 and 44, which are arranged, in particular, evenly distributed along their respective inner circumferences. The teeth 42 of the first outer gear 38 and the teeth 44 of the second outer gear 40 are, in particular, designed as rollers 37. The needle bearing 27 is, in particular, supported on the first outer gear 38.

[0052] The first inner gear 30 and the first outer gear 38 have a different number of teeth 34, 42. In particular, the number of teeth 42 of the first outer gear 38 is 1 greater than the number of teeth 34 of the first inner gear 30. Preferably, the second inner gear 32 and the second outer gear 40 also have a different number of teeth 36, 44. In particular, the number of teeth 44 of the second outer gear 40 is 1 greater than the number of teeth 36 of the second inner gear 32.

[0053] In particular, the difference in the number of teeth 34, 42 is the same as the difference in the number of teeth 36, 44. The difference in the number of teeth is therefore identical for both pairs of teeth. Specifically, the first outer gear 38 has one more tooth 42 than the first inner gear 30. Specifically, the second outer gear 40 has one more tooth 44 than the second inner gear 32. Alternatively, the difference in teeth 34, 42 or 36, 44 between the inner gears 30, 32 and their respective corresponding outer gears 38, 40 can be a plurality, in particular 2, 3, or 4.

[0054] The second outer gear 40 is mounted so as to be rotatable relative to the housing 20. How Fig. As shown in Figure 4, a rotary bearing 96 is provided between the second outer gear 40 and the frame 78, comprising an inner bearing ring 98 and an outer bearing ring 100. The inner bearing ring 98 is pressed onto the second outer gear 40 in a joining section 102. The outer bearing ring 100 is axially secured to the frame 78 by a retaining ring 104.

[0055] As the Fig. 1 and Fig. As shown in Figure 2, the transmission 16 further comprises a first output element 46 and a second output element 48. The first output element 46 has several drive pins 47 on its end face facing the electric motor 14. These drive pins extend along the longitudinal axis 12 of the transmission and are preferably arranged at equal intervals and have a largely cylindrical cross-section. The drive pins 47 are arranged corresponding to the secondary recesses 33 of the first inner gear 30 and have a smaller diameter than the secondary recesses 33. In particular, the diameter of the drive pins 47 is at least approximately twice the eccentricity dimension 23 of the eccentric 28 smaller than the diameter of the secondary recesses 33 of the first inner gear 30. The drive pins 47 are arranged in the secondary recesses 33 and can roll or rotate within them.

[0056] The first output element 46 is rotationally and displacement-resistant, in particular via at least one screw connection 51, connected to an output coupling element 49, which has several teeth 50 arranged along its circumference on its inner side, preferably at equal angular intervals. The second output element 48 is in particular formed integrally with the second outer gear 40 and has several teeth 52 arranged along its circumference on its end face, preferably at equal angular intervals.

[0057] A rotation of the drive shaft 24 causes the eccentric 28 to rotate, and the first inner gear 30 to roll against the first outer gear 38, which is stationary. In this process, the first inner gear 30, and consequently the auxiliary recesses 33, execute an elliptical (cycloidal) motion around the longitudinal axis 12 of the transmission. This causes the drive pins 47 to roll in the auxiliary recesses 33, and the first output element 46 to rotate around the longitudinal axis 12 of the transmission. In summary, the (circular) rotational motion of the drive shaft 24 around the longitudinal axis 12 of the transmission is converted into an elliptical (cycloidal) motion of the first inner gear 30 by the eccentric 28 located in the main recess 31. This elliptical movement is converted into a (circular) rotary movement of the first output element 46 around the longitudinal axis 12 of the transmission by the driver bolts 47 arranged in the secondary recesses 33.

[0058] The transmission ratio i1 of the rotational speed or torque of the drive shaft 24 and the first output element 46 is determined according to the following formula, where z1 is the number of teeth 42 of the first outer gear 38 and z2 is the number of teeth 34 of the first inner gear 30: i1=z2 / (z1−z2)

[0059] In particular, z1 is 1 greater than z2. In this case, the gear ratio i1 is determined by the number of teeth 34 of the first inner gear 30. If this gear has, for example, 19 teeth 34, the gear ratio is 1:19.

[0060] Since the first inner gear 30 and the second inner gear 32 are non-rotatably connected and, in particular, are formed in one piece, a rotation of the drive shaft 24 causes the second inner gear 32 to also perform an elliptical (cycloidal) movement about the longitudinal axis 12 of the transmission. This results in the second inner gear 32 rolling against the second outer gear 40 and driving it. Since the second outer gear 40 is formed in one piece with the second output element 48, the second output element 48 is also rotated about the longitudinal axis 12 of the transmission.

[0061] In summary, a (circular) rotary motion of the drive shaft 24 about the longitudinal axis 12 of the transmission is converted by the eccentric 28 arranged in the main recess 31 into an elliptical (cycloidal) motion of the first inner gear 30 and the second inner gear 32. By the rolling of the second inner gear 32 in the second outer gear 40, this elliptical motion is converted into a (circular) rotary motion of the second outer gear 40 and thus of the second output element 48.

[0062] The gear ratio i2 of this gear is determined according to the following formula, where z1 is the number of teeth 42 of the first outer gear 38, z2 is the number of teeth 34 of the first inner gear 30, z3 is the number of teeth 36 of the second inner gear 32 and z4 is the number of teeth 44 of the second outer gear 40: i2=1 / (1−(z1*z3 / z2*z4))

[0063] In particular, z1 is 1 greater than z2, z4 is 1 greater than z3, and the difference between z1 and z4 is equal to 1. In this case, the transmission ratio of the rotational speed or torque of the drive shaft 24 and the second output element 48 is the product of the number of teeth 34 of the first inner gear 30 and the number of teeth 44 of the second outer gear 40. For example, if the first inner gear 30 has 19 teeth 34 and the second outer gear 40 has 21 teeth 44, the transmission ratio is 1: (19 x 21 = 399).

[0064] The gearbox 16 further comprises an output shaft 58, which is rotatable about the gearbox's longitudinal axis 12. A rotary bearing 106 is provided for this purpose, comprising an inner bearing ring 108 and an outer bearing ring 110. The inner bearing ring 108 is pressed onto the output shaft 58 in a joining section 112. The outer bearing ring 110 is supported by shoulders of the clutch cover 80 and the second housing cover 82.

[0065] The transmission 16 also includes a switching device 53, by which either the first output element 46 or the second output element 48 is selectively coupled, at least indirectly, to the output shaft 58. The switching device 53 comprises a coupling element 54 and a positive-locking element 56, which is connected to the coupling element 54 in a rotationally and displacement-resistant manner. The positive-locking element 56 has several radial recesses 60 on its inner surface, which are arranged corresponding to the teeth 50 of the output coupling element 49. The positive-locking element 56 also has several axial recesses 62 on its end face, which are arranged corresponding to the teeth 52 of the second output element 48. The coupling element 54 has several radial recesses 64 on its inner surface, arranged along its circumference and preferably at equal angular intervals.

[0066] The output shaft 58 has several radially projecting teeth 66 on its outer surface, which are arranged corresponding to the recesses 64 of the coupling element 54. The output shaft 58 forms an interface to subsequent assemblies (not shown), for example, a gripping or clamping unit with gripping or clamping elements.

[0067] The transmission 16 also includes a displacement device 68, which is designed to displace the switching device 53 along the longitudinal axis 12 of the transmission and to optionally couple the first output element 46 or the second output element 48 at least indirectly with the output shaft 58.

[0068] The displacement device 68 comprises a coupling displacement element 55, which is arranged to be displaceable relative to the coupling element 54 and rotatable relative to the coupling element 54.

[0069] The displacement device 68 further comprises controllable displacement elements 70 extending along the longitudinal axis of the transmission and, in particular, including lifting magnets and / or handling elements and / or motor-spindle units and / or rotary units with guide ramps and / or rotary units with guide cams. Preferably, the displacement elements 70 are arranged at equal angular intervals from one another around the longitudinal axis 12 of the transmission. The transmission 16 further comprises return elements 72, which extend, in particular, along the longitudinal axis 12 of the transmission and are preferably designed as helical springs that counteract the force of the displacement elements 70. Preferably, the return elements 72 are also arranged at equal angular intervals from one another around the longitudinal axis 12 of the transmission.

[0070] The displacement elements 70 and the return elements 72 act on at least one driver 114, which is arranged on the coupling displacement element 55 in a displacement-resistant and, in particular, rotation-resistant manner. The driver 114 and the coupling element 54 are rotatable relative to each other about the longitudinal axis 12 of the transmission. The driver 114 is coupled to the coupling element 54 in a displacement-resistant manner, in particular via a positive-locking connection 116. The driver 114 thus transmits a control signal from the displacement elements 70 to the coupling element 54.

[0071] The housing 20 is designed in multiple parts and includes in particular a first housing cover 74, a base body 76, a frame 78, a coupling cover 80 and a second housing cover 82.

[0072] The Fig. 5 shows the gearbox diagram according to Fig. 3 in a first switching state. The Fig. Figure 6 shows a longitudinal section of the drive unit. Fig. 4 in a first switching state.

[0073] This first switching state represents an activation state, i.e., with activated sliding elements 70. Upon activation, the sliding elements 70 exert a force (in Fig. 6 “to the right”) against the action of the return elements 72, whereby the switching device 53 (in Fig. 6 is forced “to the right”. This brings the radial recesses 60 of the positive locking element 56 into engagement with the teeth 50 of the output coupling element 49. Thus, the first output element 46 is operatively coupled with the coupling element 54 and therefore also with the output shaft 58.

[0074] This coupling preferably represents a rapid traverse in which high rotational speeds or traverse rates are achieved, but only low high torques or forces can be applied. Rapid traverse is particularly suitable for efficiently bridging long travel distances, such as those encountered when clamping or gripping components with significantly different dimensions.

[0075] The Fig. Figure 7 shows the gearbox diagram according to Fig. 3 in a second switching state. The Fig. Figure 8 shows a longitudinal section of the drive unit. Fig. 4 in a second switching state.

[0076] This second switching state represents a rest position, i.e., with the displacement elements 70 not activated. (In the) Fig. 8 “to the left”) acting force of the return elements 72 will act on the switching device 53 (in Fig. 8 (to the left) is forced into the rest position. This brings the recesses 62 of the positive locking element 56 into engagement with the teeth 52 of the second output element 48. Thus, the second output element 48 is operatively coupled to the coupling element 54 and therefore also to the output shaft 58.

[0077] This coupling preferably represents a power transmission in which high torques or forces can be applied, but low rotational speeds or traverse rates prevail. The power transmission is particularly suitable for the precise control or movement of gripping or clamping elements, as well as for applying high gripping or clamping forces.

[0078] The Fig. Figure 9 shows a schematic representation of an electronic gripping or clamping device 120 according to the invention. The electronic gripping or clamping device 120 comprises a drive unit 10 with an electric motor 14 and a gearbox 16, wherein the drive unit 10, the electric motor 14 and the gearbox 16 are arranged according to the Fig. 1 to 8. Furthermore, a carrier plate 122 is provided on which several gripping or clamping elements 124, movable towards and away from each other, are arranged. The drive unit 10 is designed to displace the gripping or clamping elements 124 preferably radially to the longitudinal axis 12 of the transmission and thereby selectively fix or release a component (not shown) to be gripped or clamped.

Claims

[1] Gearbox (16) comprising - a drive shaft (24), - an eccentric (28), - a first internal gear (30) comprising teeth (34), - a first external gear (38) comprising teeth (42), - a first output element (46) and - an output shaft (58), wherein the drive shaft (24) and the output shaft (58) are arranged coaxially to each other along a longitudinal axis (12) of the transmission, wherein the drive shaft (24) and the eccentric (28) are connected to each other in a rotationally fixed manner, wherein the first internal gear (30) has at least one largely centrally arranged, preferably circular, main recess (31), wherein the eccentric (28) is arranged in the main recess (31) of the first internal gear (30), wherein the eccentric (28) and the first internal gear (30) are rotatable relative to each other, wherein the first inner gear (30) and the first outer gear (38) have a different number of teeth (34, 42), wherein the first inner gear (30) rolls on the first outer gear (38) and thereby performs an elliptical movement around the longitudinal axis (12) of the transmission, wherein the first inner gear (30) has several secondary recesses (33), wherein the secondary recesses (33) are arranged around the main recess (31), wherein the first output element (46) has several drive pins (47), wherein the drive pins (47) have a smaller diameter than the secondary recesses (33) of the first internal gear (30), wherein the drive pins (47) are arranged such that they engage correspondingly in the secondary recesses (33) of the first inner gear (30), characterized by , that the transmission (16) includes a second internal gear (32) comprising teeth (36), wherein the first inner gear (30) and the second inner gear (32) are connected to each other in a rotationally fixed manner, wherein the transmission (16) comprises a second external gear (40) comprising teeth (44), wherein the second inner gear (32) rolls in the second outer gear (40) and drives it, wherein the transmission (16) comprises a second output element (48), wherein the second output element (48) is non-rotatably connected to the second outer gear (40), wherein the transmission (16) comprises a switching device (53), wherein the switching device (53) can be selectively engaged with the first output element (46) or with the second output element (48), and wherein the switching device (53) is engaged with the output shaft (58). [2] Gearbox (16) according to claim 1, characterized by , that the second inner gear (32) and the second outer gear (40) have a different number of teeth (36, 44), wherein the difference in the number of teeth (34, 42) of the first inner gear (30) and the first outer gear (38) and the difference in the number of teeth (36, 44) of the second inner gear (32) and the second outer gear (40) are equal. [3] Gearbox (16) according to claim 1 or 2, characterized by , that the first inner gear (30) and the second inner gear (32) have a different number of teeth (34, 36). [4] Gearbox (16) according to any of the preceding claims, characterized by , that the first inner gear (30) and the second inner gear (32) are connected to each other in a way that prevents displacement. [5] Gearbox (16) according to any one of the preceding claims, characterized by , that the second outer gear (40) and the second output element (48) are connected to each other in a way that prevents displacement. [6] Gearbox (16) according to any one of the preceding claims, characterized by , that the switching device (53) includes a clutch element (54) which can be displaced along the longitudinal axis (12) of the transmission. [7] Gearbox (16) according to claim 6, characterized by , that the coupling element (54) is connected to at least one positive locking element (56) in a rotationally fixed manner, wherein optionally the first output element (46) or the second output element (48) engages positively in the positive locking element (56). [8] Gearbox (16) according to claim 7, characterized by , that the first output element (46) engages radially in recesses (60) of the positive locking element (56) or the second output element (48) engages axially in recesses (62) of the positive locking element (56). [9] Gearbox (16) according to any one of claims 6 to 8, characterized by, that the switching device (53) includes at least one displacement device (68) which can displace the clutch element (54) along the longitudinal axis (12) of the transmission. [10] Gearbox (16) according to any one of the preceding claims, characterized by , that the first outer gear (38) is connected to a housing (20) of the gearbox (16) in a rotationally fixed and, in particular, also displaceably fixed manner. [11] Gearbox (16) according to any one of the preceding claims, characterized by , that the drive shaft (24) and the eccentric (28) are positively connected to each other. [12] Drive unit (10), in particular for use in electronic gripping or clamping devices, comprising a gearbox (16) according to one of claims 1 to 11, a control device (18) and an electric motor (14), wherein an output shaft (22) of the electric motor (14) is rotationally fixed to the drive shaft (24) and / or is formed integrally with the drive shaft (24). [13] Drive unit (10) according to claim 12, characterized by , that the control device (18) is configured to engage the switching device (53) either with the first output element (46) or with the second output element (48), depending on at least one controlled variable. [14] Drive unit (10) according to claim 13, characterized by , that the at least one controlled variable includes a sensor signal and / or a length measurement and / or a diameter measurement and / or a distance measurement and / or a weight measurement and / or a position measurement and / or a load measurement and / or an external input value. [15] Method for operating the drive unit (10) according to claim 14, characterized by , that with large distance dimensions the switching device (53) is engaged with the first output element (46), and / or that with large weight dimensions or large load dimensions the switching device (53) is engaged with the second output element (48). [16] Electronic gripping or clamping device (120) comprising the drive unit (10) according to any one of claims 12 to 14 and at least two gripping or clamping elements (124) for gripping and / or clamping a component.

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