Drive unit for agitators

Abstract

Drive unit for agitators with agitator tools (3; 4), wherein a drive shaft (1) or a ring gear (8) directly drives a part of the agitator tools (3; 4), wherein a lower agitator tool (4) is rigidly connected to a planetary gear (2), characterized in that a planetary gear carrier (9) of the planetary gear (2) is rigidly connected to a point (12) outside the gear during operation and the drive shaft (1) is rigidly connected to a sun gear (6) of the planetary gear (2), wherein an upper agitator tool (3) is rigidly connected to a ring gear (8) of the planetary gear (2), such that the drive shaft (1) or the ring gear (8) drives the upper agitator tool (3) via the planetary gear (2) in the opposite direction to the lower agitator tool (4) during operation.

Description

Description of the invention

[0001] The present invention relates to a drive unit for agitators with stirring tools, wherein a drive shaft or a ring gear directly drives part of the stirring tools, wherein a lower stirring tool is fixedly connected to a planetary gear. State of the art

[0002] Such a drive unit is known from DE 35 20 040 A1, DE 34 04 713 A1, and DE 10 2012 206 162 A1. These prior art drive units feature multiple drive shafts or split drive shafts, each for a stirrer. These drive shafts are connected to one another via a planetary gear system such that the combination of two drive shafts results in the two drive shafts rotating in opposite directions. Such a combination of multiple drive shafts, each for a stirrer, has the disadvantage that the position of the stirrers in such a drive unit is fixed. Such a drive unit cannot, for example, be used in vessels of varying depths.

[0003] CN 1 07 519 799 A1 discloses a drive unit in which a drive shaft does not directly drive an agitator. A drive unit drives a sun gear spatially separated from the drive shaft via a drive shaft and a transmission chain. However, this prior art has the same disadvantages as mentioned above.

[0004] To improve mixing, the stirring speed is usually increased. However, as the stirring speed increases further, the liquid surface sinks centrally, resulting in the formation of a vortex. This vortex formation develops further as the stirring speed increases and, in extreme cases, can even lead to the exposure of the stirring tool. This vortex formation usually leads to the unwanted entrainment of air and, if the stirring tool is exposed, also to undesirable uneven running of the stirring tool, as the liquid bearing of the stirring tool is massively disrupted. The high stirring speed not only lowers the liquid in the center, but also significantly increases the liquid level at the edges of the container. Both effects reduce the mixing performance of the agitator.

[0005] The circulating of liquid in cylindrical containers can be remedied by installing baffles or an additional agitator. This must be taken into account for new systems; retrofitting existing systems or when stirring in existing containers such as drums, IBCs, etc., the installation of additional separate agitators is not possible due to space constraints. In most cases, the container openings are too small for this, or the existing tripod agitators cannot be retrofitted. Due to the container geometry, an eccentric arrangement of the agitator is also not possible. Equipping them with baffles is also difficult, as the containers only have small openings, and even if the container opening does allow it, secure attachment of the baffle is usually not possible.

[0006] When using two drives, it is generally possible to set different stirring directions and speeds, as described in EP 0 461 746 B1 or DE 39 01 778 C2. This, of course, results in the additional expense of a second drive and the corresponding space requirements; this is hardly possible, especially for retrofits.

[0007] Documents DE 103 14 804 A1 and US 969 120 A describe coaxial counter-rotating agitators with a gear drive. This is a non-asymmetrical gear, and the required torque can only be transmitted via a gear. For higher torques, it will require a correspondingly large size. The gear itself is permanently installed and does not rotate. Due to the one-sided force application, supporting the hollow shaft and guiding it without play is difficult.

[0008] DE 69 34 105 U describes a laboratory stirrer with counter-rotating stirring tools using a reversing gear. DE 18 03 541 U also describes a counter-rotating laboratory stirrer with a reversing gear. The first stirring tool is driven directly by the motor armature shaft, while the second stirring tool rotates in the opposite direction. A ball cage of an axial bearing is connected to the stirring tools via a hollow shaft. The movement is transmitted by the rolling of the balls in the axial bearing, driven by the armature shaft. Neither stirrer is likely capable of transmitting higher torques, and a desired gear reduction or step-up ratio is also not possible.

[0009] DE 27 35 102 A1 uses an epicyclic gear, where the opposing rotational movement is to be absorbed by the planetary gears. The solid shaft is connected to the sun gear and serves as the drive for the epicyclic gear, while the hollow shaft is connected to the planetary gears. The hollow shaft is then intended to move in the opposite direction to the sun gear. If the sun gear is driven by the solid shaft, the planetary carrier will move in the same direction of rotation, thus preventing an opposing rotational movement. Furthermore, no fixed point outside the gear is described. Task

[0010] The object of the invention is to further develop a drive unit of the type mentioned above in such a way that it is compact, can be retrofitted to existing systems if necessary, and can be adapted to different containers. It must also be possible to utilize small container openings, for example, to install hinged agitators.

[0011] This object is achieved according to the invention in that a planet gear carrier of the planetary gear is firmly connected to a point outside the gear during operation, and the drive shaft is firmly connected to a sun gear of the planetary gear, wherein a ring gear of the planetary gear is firmly connected to at least one second stirring tool, such that the drive shaft or the ring gear drives a second stirring tool via the planetary gear in the opposite direction to the second stirring tool during operation. Examples of implementation

[0012] Embodiments of the present invention are described in more detail with reference to the drawings: Fig. 1 a front view through the drive unit with planetary gear according to the present invention in a first embodiment, with a section through the planetary gear; Fig. 2 a front view through the drive unit with planetary gear according to the present invention in a second embodiment, with a section through the planetary gear; and Fig. 3 a front view through the drive unit with planetary gear according to the present invention in a third embodiment, with a section through the planetary gear, additionally with a support bridge.

[0013] Based on the Fig. A first embodiment of the invention is explained below in Figure 1. It shows a front view with a section through a planetary gear 2. The illustrated drive unit consists of a drive shaft 1 and the planetary gear 2, as well as an upper 3 and a lower stirring tool 4. The planetary gear 2 is arranged on the drive shaft 1 of the drive unit. The drive shaft 1 extends through the planetary gear 2 and is connected via a clamping connection 5 to a sun gear 6 of the planetary gear 2, thereby driving the planetary gear 2.

[0014] The planetary gear unit 2 consists of the sun gear 6, planet gears 7, a planet gear carrier 9, and an external ring gear 8. The planet gears 7 are located between the sun gear 6 and the ring gear 8 and are mounted on a planet gear carrier 9. This planet gear carrier 9 is structurally guided to the outside of the planetary gear unit 2 and has mounting receptacles 10 there. A torque arm 13 connects the planet gear carrier 9 to a fixed point 12 outside the planetary gear unit 2. The fixed point 12 can be, for example, mounting points for the drive itself, such as the drive support in tripod agitators or the bridge in container agitators, or even a mounting flange on or in a container. Thus, the planet gear carrier 9 cannot move. The ring gear 8 closes off the planetary gear unit 2 to the outside. Mounting points 11 are located on this ring gear 8.A holder 14 with the upper stirring tools 3 is attached to these fastening points 11.

[0015] Due to this arrangement and fastening of the planetary gear 2, when the drive shaft 1 rotates, there is a rotational movement of the sun gear 6 with the lower stirring tools 4 and a rotational movement of the ring gear 8 and the upper stirring tools 3 attached to it in the opposite direction of rotation to the drive shaft 1.

[0016] The gear ratio can be selected by appropriately selecting the gears (sun gear 6, planetary gears 9, ring gear 8), and power is transmitted via multiple gears, thus allowing high torques to be transmitted. A further advantage of the planetary gear 2 is its smooth running and compact design.

[0017] It is also possible for the drive shaft 1 to be connected to the sun gear 6 using other detachable and non-detachable connections. If the power is transmitted from the drive shaft 1 to the sun gear 6 using a clamp connection 5, the planetary gear 2 can also be moved to the desired position on the drive shaft 1 of the drive. In this case, the torque arm 13 must also be able to accommodate the change in length.

[0018] Due to the compact design of the planetary gear 2, it can also be guided through small container openings. When equipped with folding agitators, this variant can also be used in IBC containers with limited opening diameters.

[0019] The planetary gear 2 is designed in such a way that it can have contact with the stirring medium itself; this can be achieved by selecting suitable materials and using appropriate seals Fig. 2 Version with hollow shaft 15

[0020] The illustration Fig. 2 shows a second embodiment according to the invention with a hollow shaft 15. The torque support 13 also ensures the fixation of the planetary gear carrier 9 outside the transmission. Fig. 03 Version with hollow shaft 15 and support bridge 16

[0021] The illustration Fig. Figure 3 shows a third embodiment of the invention with a hollow shaft 15 and the transmission mounted outside a container by means of a support bridge 16. The planetary gear carrier 9 is fixed directly to the support bridge 16. The hollow shaft 15 can be sealed to the container by selecting a suitable seal 17. List of reference symbols 1 drive shaft 2 planetary gears 3 upper stirring tool 4 lower stirring tool 5 clamp connection 6 Sun gear 7 planetary gears 8 ring gear 9 planetary gear carrier 10 mounting points planet gear carrier 11 mounting points ring gear 12 fixed point 13 Torque support 14 holders 15 Hollow shaft 16 Girder bridge 17 Sealing hollow shaft

Claims

[1] Drive unit for agitators with agitating tools (3; 4), wherein a drive shaft (1) or a ring gear (8) directly drives part of the agitating tools (3; 4), wherein a lower agitating tool (4) is fixedly connected to a planetary gear (2), characterized by in that a planet gear carrier (9) of the planetary gear (2) is firmly connected to a point (12) outside the gear during operation and the drive shaft (1) is firmly connected to a sun gear (6) of the planetary gear (2), wherein an upper stirring tool (3) is firmly connected to a ring gear (8) of the planetary gear (2) in such a way that the drive shaft (1) or the ring gear (8) drives the upper stirring tool (3) via the planetary gear (2) in the opposite direction to the lower stirring tool (4) during operation. [2] Drive unit according to claim 1 characterized by that the ring gear (8) is connected to the upper stirring tool (3) via a holder (14) or a hollow shaft (15). [3] Drive unit according to one of claims 1 or 2, characterized by that the planet gear carrier (9) is guided on both sides of the gearbox (2). [4] Drive unit according to one of claims 1 to 3, characterized by that the planetary gear (2) is detachably fastened to the drive shaft (1) via a clamping connection (5) such that the planetary gear (2) can be moved on the drive shaft (1) to a desired position. [5] Drive unit according to one of claims 1 to 4, characterized by that several stirring tools (3; 4) are attached to the drive shaft (1). [6] Drive unit according to one of claims 1 to 5, characterized by that the connection from the drive shaft (1) to the sun gear (6) is made by force-locking or form-locking connections. [7] Drive unit according to one of claims 1 to 6, characterized by that the drive shaft (1) is hollow. [8] Drive unit according to one of the preceding claims, characterized by that the planetary gear (2) is designed as an epicyclic gear.

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