Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H1/00—Toothed gearings for conveying rotary motion
  • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
  • F16H1/32—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H1/00—Toothed gearings for conveying rotary motion
  • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
  • F16H1/32—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear
  • F16H1/321—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear the orbital gear being nutating
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H57/00—General details of gearing
  • F16H57/02—Gearboxes; Mounting gearing therein
  • F16H57/029—Gearboxes; Mounting gearing therein characterised by means for sealing the gearboxes, e.g. to improve airtightness
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J15/00—Sealings
  • F16J15/50—Sealings between relatively-movable members, by means of a sealing without relatively-moving surfaces, e.g. fluid-tight sealings for transmitting motion through a wall
  • F16J15/52—Sealings between relatively-movable members, by means of a sealing without relatively-moving surfaces, e.g. fluid-tight sealings for transmitting motion through a wall by means of sealing bellows or diaphragms
  • F16J15/525—Sealings between relatively-movable members, by means of a sealing without relatively-moving surfaces, e.g. fluid-tight sealings for transmitting motion through a wall by means of sealing bellows or diaphragms fixed to a part of a transmission performing a wobbling or a circular translatory movement
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H1/00—Toothed gearings for conveying rotary motion
  • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
  • F16H1/32—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear
  • F16H2001/323—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear comprising eccentric crankshafts driving or driven by a gearing
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H1/00—Toothed gearings for conveying rotary motion
  • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
  • F16H1/32—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear
  • F16H2001/327—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear with orbital gear sets comprising an internally toothed ring gear

Definitions

• the invention relates to a rotary feedthrough for the transmission of rotational movements, in particular to a transmission rotary feedthrough, which can be advantageously hermetically sealed.
• a hermetic shield can advantageously be realized.
• the disadvantage is provided for them but no translation of the rotational movements.
• only small torques of, for example, a maximum of 5 or 10 Nm can usually be transmitted through them.
• a cycloidal gear is a special form of eccentric gear.
• the mode of operation of a cycloidal drive can be illustrated by means of FIG. 2 from [2].
• An eccentric drives with a rotational movement D1, for example via a ball bearing, an inner cam with curve sections of the number i. The cam rotates in a fixed outer bolt ring with i + 1 bolt and thus performs even a tumbling rotational movement D2 ⁇ D1. With each revolution of the drive wheel, the output continues to move around a curve section. The rotational movement of the inner cam can be tapped off via bolts and transferred to the output shaft.
• the output shaft of a cycloidal transmission generally has significantly lower speeds compared to the drive rotation.
• Cycloidal transmissions also have the advantage, with respect to vacuum applications, that the cams transmit the torque in a rolling manner.
• Cycloidal transmissions are usually very durable and require little maintenance.
• Both eccentric and cycloidal transmissions can be constructed in a variety of arrangements and gear stages. This high regular translations can be achieved. Typical translations for single-stage cycloidal transmissions range, for example, from 29: 1 to 179: 1. These gears can be loaded with high torque (compact gearbox up to several thousand Nm commercially available) and also overloaded with shocks by a factor of 5. In addition to the high load capacity and high positioning accuracies can be achieved, typically ⁇ 1 arcmin. The aforementioned gearboxes are therefore often used in robotics. However, due to the lack of sealing capabilities, a cycloidal gearbox is generally not suitable for use as a rotary feedthrough at the boundary between two spaces with different pressures (P1, P2), and especially at the boundary between vacuum and atmosphere. Task and solution
• the object of the invention is to enable a rotary feedthrough for transmitting a mechanical rotary movement from a first room to a second room, where in which spaces can be hermetically separated, such as in vacuum applications
• the rotary feedthrough according to the invention therefore comprises an optimized combination of an eccentric or cycloidal drive with a bellows seal. If the rotary feedthrough is to be operated at least on one side in a vacuum, pay attention to vacuum-compatible materials
• An eccentric movement is understood to mean a movement of a body in which all points of the body rotate at equal angular velocity on circles of equal size around different parallel axes. Unlike rotation, the body does not change its orientation in space. It is therefore a pure translation.
• eccentric for example, rotary (rotary) can be converted into translational (length) movements and vice versa.
• the purpose of the eccentric may be on the one hand the implementation of rotational to longitudinal movement or on the other hand, a power gain, in general, both effects are desired.
• the rotary feedthrough comprises a first shaft with a means for coupling this shaft with a first gear and a mounted in a housing second shaft which is connected to a second gear.
• the first and second gear are on the one hand an internal gear with i + x internal teeth and an external gear 6 with i external teeth.
• the dimensions of the external gear in relation to the internal gear are such that the external gear is able to shift in the internal gear.
• the rotary feedthrough comprises at least one means for sealing, which between a housing and one of the gears - depending on the embodiment of the invention - is arranged, and which preferably comprises a seal, for example a bellows.
• a housing is understood to mean a part of a delimitable space into or out of which a rotational movement is to be effected by the rotary feedthrough according to the invention.
• the first shaft is operated as a drive shaft and, accordingly, the second shaft as an output shaft. This is not mandatory.
• the fixedly mounted in the housing second shaft is fixedly connected to a gear.
• Hard in this context does not necessarily mean a cohesive connection, but only that there is a 1: 1 transmission of the rotational movement of the shaft and the associated gear.
• the first shaft is in contrast connected via a means for coupling with the respective other gear, which allows a transmission of the rotational movement of the shaft in an eccentric movement of the associated gear.
• the external gear and the internal gear are geometrically matched to each other.
• the external gear is disposed within the internal gear in such a manner that the external gear can roll on the internal gear, if the internal gear is fixedly connected to a shaft, or the internal gear can roll around the external gear, if the external gear is fixedly connected to a shaft.
• the second shaft is fixedly connected to an external gear or an internal gear.
• the first shaft is connected in each case via the means for coupling with the respective other gear.
• the means for coupling for example, an eccentric to call, which is fixedly connected to the first shaft and in particular via a bearing, the gear coupling to the shaft.
• the rotational movement of the drive shaft thus results in the not centrally disposed recess to an eccentric movement, which is transmitted via a pin on the inner or outer gear.
• Pin and recess are geometrically matched to each other.
• the eccentric on a not centrally arranged with respect to the first shaft pin which engages in a centrally arranged on the inner or outer gear recess.
• the rotational movement of the first shaft also leads via the non-centrally arranged pin to an eccentric movement, which is transmitted via a pin to the recess of the inner or outer gearwheel.
• pin and recess are geometrically matched to each other.
• a further alternative embodiment of the coupling means 2 provides that the first shaft is angled at the end and the end of which ends in a pin which engages in a recess centrally arranged on the gear to be coupled.
• pin and recess particularly easily on a bearing, for. As a ball bearing, be flexibly connected.
• the gearwheel coupled to the first shaft can perform no rotational movement but only a 2-dimensional eccentric movement perpendicular to the axis of the first shaft, it is advantageously possible to realize a seal between the housing and the gearwheel coupled to the first shaft.
• This seal may in particular be hermetic, so that on the drive and the driven side of this rotary feedthrough two distinct spaces arise, which may differ by the prevailing pressure and / or media containing them (gas / liquid), without the transmission of rotational movement is influenced by it.
• the means for sealing is advantageously flexible designed, since it must accommodate the eccentric movement of the coupled to the shaft 1 gear relative to the housing.
• the means comprises, for example, one or more bellows or else only one flexible foil.
• the material used in the seal can be advantageously adapted to the corresponding requirement with respect to the temperature, the set pressure difference, or even the existing media (aggresive, corrosive, etc.).
• the operation of the rotary feedthrough according to the invention according to a first embodiment will be described below, without this being to be understood as a restriction.
• the first shaft (in this case the drive shaft) with an eccentric as means for coupling transmits the rotational movement D1 of the shaft in an eccentric movement of the coupled thereto the internal gear.
• the eccentric movement of the internal gear 5 causes the external gear fixedly connected to the second shaft (here output shaft) to roll on the teeth of the internal gear wheel and thereby undergo a rotational movement D2 itself. Due to the arrangement of i + x teeth on the internal gear and i teeth on the external gear, the rotational movements are transmitted in such a way that a rotational movement D2 ⁇ D1, ie a reduction, results on the output side.
• the internal gear Due to the fact that the internal gear carries out an eccentric movement but no rotational movement, it can advantageously be connected via a hermetic seal to a housing in which the output shaft 3 is mounted.
• the seal comprises a bellows. This embodiment is thus particularly suitable to apply the rotary feedthrough to a boundary of two rooms with different pressures.
• a pressure P1 can be set in the housing, while outside the housing, on the side of the drive shaft, there is a pressure P2> P1.
• the difference between the rotary feedthrough according to the invention and a cycloidal drive lies in the fact that an internal circular disk with external teeth (external gear) is simultaneously displaced into eccentric motion and rotational motion by the rotational movement of the drive shaft in a cycloidal gear, while in the rotary feedthrough according to the invention the internal gear wheel is only in an eccentric motion is offset.
• the drive shaft relative to the output shaft can be advantageously hermetically sealed, so that such a rotary feedthrough is particularly suitable for the transmission of a rotational movement in or out of a vacuum.
• the seal can be done for example via one or more bellows.
• the crucial point in the invention lies in the transition of a rotational movement D1 of a first shaft (in particular a drive shaft) in a translational movement only (eccentric movement), and from this back to a rotational movement D2 of the output shaft, combined with the possibility of a hermetic seal , which allows the application of this device, especially at the boundary between atmospheric pressure and vacuum.
• a rotational movement D1 of a first shaft in particular a drive shaft
• a rotational movement D2 of the output shaft combined with the possibility of a hermetic seal , which allows the application of this device, especially at the boundary between atmospheric pressure and vacuum.
• an additional Oldham coupling can optionally also ensure that the gearwheel coupled to the drive shaft exclusively performs an eccentric movement and no rotational movement and thus the seal also does not undergo rotational movement or has to intercept it.
• a first shaft transmits the rotational movement D1 of the drive shaft via a means for coupling in an eccentric movement of the external gear coupled to the drive shaft.
• the eccentric movement of the external gear leads analogous to the operation of a cycloidal to the fact that the firmly connected to the second shaft (output shaft) internal gear rolls on the teeth of the external gear and thereby undergoes a rotational movement D2 itself.
• the arrangement of i teeth on the external gear and i + x teeth on the internal gear also in this embodiment, a transmission of the rotational movement such that a rotational movement D2 ⁇ D1, ie a reduction results.
• the hermetic seal is in this case between the housing and the external gear, wherein optionally the external gear has an additional device that extends beyond the dimensions of the correlating with the external gear internal gear, so as to allow a good connection of the seal to the housing.
• This additional device can be considered as part of the external gear or as part of the seal.
• Such an additional device could for example be a circular disc which is fixed on the outside of the rolling in the internal gear external gear and has a much larger diameter than the internal gear.
• On the outer edge then, for example, could set a bellows, which is connected to the housing, so that even with an eccentric movement of the outer gear, the bellows does not abut against the internal gear.
• this embodiment is thus particularly suitable to apply the rotary feedthrough to a boundary of two rooms with different pressures or media that must be sealed from each other.
• the means for sealing itself can in the simplest case consist of a bellows seal with only one bellows. But there are also embodiments with multiple Balgabdichtungen possible. It is also conceivable, depending on the geometry of the housing at the location of the rotary feedthrough any other flexible way of sealing, as long as it allows an eccentric movement relative to a fixed housing, such as a flexible film.
• the sealing should be suitable for the possible fields of application and the temperatures and pressure conditions set there. When used in aggressive media, attention must be paid to appropriate stability and durability of the materials used, in particular the bellows or the film.
• rotary feedthrough can do without lubricant, and thereby the scope of this rotary feedthrough is not limited to certain temperature ranges, as is otherwise known from the prior art for gearboxes with lubricants used only in a specific temperature interval or operated.
• the high positioning accuracy is achieved by a high reduction and simultaneous backlash of the transmission, with a corresponding stiff torque support is assumed.
• the rolling friction of all elements involved in the transmission also ensures a very low breakaway torque.
• gears or the heat-be- layering of gears all common materials are suitable, as they are already known from the prior art for cycloidal gear. Particular mention should be made of metals, high-performance plastics and ceramics, wherein the gears may be made entirely from these materials or may be coated only with these materials.
• Ceramics are particularly advantageous for use in a vacuum or high vacuum, since they do not require any lubricant, have a high load rating, ie. H. are highly resilient, and are particularly suitable for high temperatures and high speeds. It would even be sufficient if only one of the gears, so the internal gear or external gear, would be made of a ceramic, would include a ceramic or would be coated only with a ceramic.
• a clutch can additionally be provided, which can compensate for an axial displacement between the input and output shafts.
• a particularly well suited for this coupling is, for example, an Oldham clutch.
• Figure 1 Schematic representation of the so-called cat tail principle from [1].
• Figure 2 Schematic representation of a cycloidal from [2].
• FIG. 3 Schematic sectional drawing of an embodiment of the invention
• Rotary feedthrough with an integral with the output shaft internal gear.
• FIG. 4 Schematic sectional drawing of an embodiment of the invention
• FIG. 5 Schematic sectional drawing of an embodiment of the invention
• FIG. 6 Schematic representation of exemplary embodiments of the means for coupling between a drive shaft and an inner or outer gear.
• Figure 7 Schematic representation of the meshing of an external gear with i + x
• Teeth in an internal gear with i teeth Teeth in an internal gear with i teeth.
• Figure 8 Schematic sectional drawings of a particular embodiment of the rotary feedthrough according to the invention with additional support by a Oldhamkupplung.
• FIG. 9 Schematic representation of an Oldham clutch
• Figure 10 Schematic representation of a particular embodiment of the inventive rotary feedthrough, here with 10 bolts / rolling elements as an internal gear and a cam with 9 teeth as external gear in cross section.
• the internal gear 5 does not rotate about its own axis, but merely performs an eccentric predetermined by the eccentric movement. As can be seen from FIG. 3, the internal gear wheel 5 can thereby be supported against rotation and sealed, for example, by a bellows 7 relative to a housing 4.
• the external gear 5 is set by the eccentric movement of the internal gear 6 itself in a rotational movement.
• FIG. 4 shows a further embodiment of the invention, in which now the drive shaft 1 with an external gear 6 and the output shaft 3 is fixedly connected to a réelle leopard- 5. Again, there is a conversion of a rotational movement D1 of the drive shaft 1 first in an eccentric movement of the external gear 6, which causes a rotational movement D2 of the corresponding internal gear 5, which transmits them to the fixedly connected output shaft 3.
• FIG. 5 shows a further embodiment of the invention similar to that shown in FIG. However, in this case, the seal is not made by a bellows but due another geometric arrangement of the housing by a flexible, gas-impermeable film.
• FIG. 6 shows by way of example possible and suitable embodiments of the coupling between the drive shaft 1 and an eccentric 2 fixedly connected thereto on one side and the gearwheel connected thereto in a flexible manner, this depending on the embodiment both an internal gearwheel and an external gearwheel (not shown here). can be.
• an internal gearwheel and an external gearwheel not shown here.
• an additional eccentric because here an angled drive shaft 1 at the same time assumes the function of an eccentric.
• FIG. 7 shows the central arrangement of an external gearwheel 6 and that of the encircling internal gearwheel 5 in cross section. Due to the fact that the internal gear i + x teeth, but the external gear 6 has only i teeth, the external gear is forced into a rotational movement by an eccentric movement of the internal gear wheel, since the teeth of the external gear roll on the internal gear accordingly. Due to the different number of teeth, it is thus imperative always to a reduction of the rotational movements of drive and output shaft. A 1: 1 transmission of the rotational movement of the drive shaft to the output shaft can thus not be realized with the rotary feedthrough according to the invention in this embodiment.
• FIG. 8 shows an embodiment of the rotary feedthrough according to the invention with an additional support by means of an Oldham coupling (FIG. 9, section B-B).
• the drive shaft 1 generates a circular movement of the cycloidal disk 6.
• a bellows 7, which allows the hermetic seal to the housing 4, is fastened to the cycloidal disk 6.
• the moment support of the cycloid disc (cam disc) 6 is effected by the Oldham clutch 10.
• this consists of a disc with two horizontal 1 1 and a vertical 12 slot. In the horizontal slots 11 engage on the cam 6 fixed sleeves 13. In the vertical slot engages a web 14 which is fixedly connected to the housing 4. Basically, even with cycloidal gearboxes the Oldham clutch can be dispensed with and the moment can be supported via the bellows.
• FIG. 10 shows the engagement of the rolling bodies 15 in the cycloidal disk (cam disk).
• the rolling elements are in turn held by roller bearings 16 here.
• the entire gear stage can thus be implemented purely rolling. Cycloidal transmissions are usually not self-locking. It is thus possible to change from drive to output side. In this way, for example, a faster rotary motion could be generated in a vacuum.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Retarders (AREA)
• Gears, Cams (AREA)
• Sealing Devices (AREA)
• Diaphragms And Bellows (AREA)
• General Details Of Gearings (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=61972269

Family Applications (1)

Country Status (6)

Families Citing this family (1)

Family Cites Families (4)

• 2017
  • 2017-04-05 DE DE102017003305.6A patent/DE102017003305A1/de not_active Withdrawn
• 2018
  • 2018-03-10 JP JP2019548010A patent/JP2020515779A/ja not_active Withdrawn
  • 2018-03-10 CN CN201880015186.4A patent/CN110325763A/zh not_active Withdrawn
  • 2018-03-10 WO PCT/DE2018/000063 patent/WO2018184611A1/de unknown
  • 2018-03-10 EP EP18717822.3A patent/EP3607225A1/de not_active Withdrawn
  • 2018-03-10 US US16/490,610 patent/US20200018381A1/en not_active Abandoned

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