WO2013010667A1

WO2013010667A1 - Decanter centrifuge

Info

Publication number: WO2013010667A1
Application number: PCT/EP2012/003028
Authority: WO
Inventors: Harry Gaus
Original assignee: Harry Gaus
Priority date: 2011-07-19
Filing date: 2012-07-18
Publication date: 2013-01-24
Also published as: DE102011108008A1; DE202012012743U1

Abstract

In the case of a decanter centrifuge (1) comprising a centrifuge drum (2) and an extruder screw (3) rotatably mounted in the centrifuge drum (2), wherein the extruder screw (3) is driven by an electric drive (7) rotating with the centrifuge drum (2), it is proposed to arrange a feed wheel (19) in the drive train between an electric motor (11) of the drive (7) and the extruder screw (3), with which wheel lubricant is fed from the inner side (20) of a housing (13) of the drive (7) by a relative movement of the feed wheel (19) towards the housing (13) into a lubricant circulation for lubricating and cooling the drive (7), wherein the feed wheel (19) is mounted in a rotatably sliding manner on a shaft (16, 17) of the drive train and is held fixed in space during operation.

Description

Decanter centrifuge

The invention relates to a decanter centrifuge with a motor-driven, rotating centrifuge drum and a mounted therein, rotatable relative to the centrifuge drum extruder screw, wherein a drive for the extruder screw is provided which has an electric motor and a reduction gear, in a connected to the centrifuge drum and with this are arranged with the rotating housing, wherein a first motor part (stator or rotor) of the electric motor is connected to the housing and runs with the centrifuge drum and a second motor part (rotor or stator), which rotates with the motor shaft drives the reduction gear and wherein the output shaft of the Reduction gear with the extruder screw in drive ^¬ compound is.

Decanter centrifuges serve to separate an emulsion into a liquid and a solid phase in a continuous process. In most applications, the liquid phase is water, and the solid phase is a specific heavy matter that is sentimentally sent to the inner wall by the rotation of the centrifuge drum as the liquid phase accumulates toward the center of rotation. Through a concentric extruder screw within the centrifuge drum, which rotates relative to the high-speed rotating centrifuge drum, the solid phase is transported axially to an outlet, further compressed, dewatered and extruded from the outlet. The liquid phase can move the centrifuge drum against the movement of the extruder screw through an overflow at the other

CONFIRMATION COPY Exit the centrifuge drum.

The extruder screw must perform a rotation at low speed, but large torque relative to the centrifuge drum. For reasons of process control, the relative speed between the centrifuge drum and extruder screw should be adjustable and independent of the speed of the centrifuge drum. Decanter centrifuges are known in numerous designs.

For example, DE-AS 1 086 181 discloses a decanter centrifuge in which one part, for example the centrifuge drum, is driven by a motor and the other part, in this case the extruder screw, is braked via an intermediate epicyclic gearbox with a larger reduction.

Similarly, US Pat. No. 5,772,573 A discloses a decanter centrifuge in which the central shaft of a Harmony Drive with the characteristic elliptical roller bearing is fixed in space or driven by a stationary motor at low speed, while the flexible spline and the Ring gear of the Harmony Drive are co-rotated with the centrifuge drum, the extruder screw is rotatably connected to the ring gear.

DE 30 02 449 C2 shows and describes a device for controlling the relative rotational speed between the centrifuge drum and the extruder screw with two series-connected hydraulic motors and a planetary gear.

In US 3,734,399 it is proposed the centrifuge drum to drive by means of a drive motor via a hydrodynamic coupling and belt drive and the extruder screw via a controllable hydraulic pump coupled thereto, a hydraulic motor and a differential gear.

In the drives of these devices there is in each case a reaction between the centrifuge drum and the extruder screw in such a way that the drives are not independently controllable, but influence each other. In extreme cases, this can lead to the drive of the extruder screw being able to change from a drive movement into a braking movement.

The moments of the centrifuge drum and extruder screw are each based on a space-fixed machine frame, whereby the undesirable reaction arises.

Devices are also known in which the drive of the extruder screw is attached to the centrifuge drum, whereby the undesired reaction is minimized or eliminated. However, there is still a dependency on a common main drive and limited control ranges. For example, DE 25 25 280 C2 proposes directly driving the centrifuge drum by means of a drive motor by means of drive belts, while the extruder screw can be driven independently by means of a co-rotating hydraulic motor with rotary unions for the hydraulic fluid. With an increase in the working pressure in the hydraulic system, due to a high accumulation of solids in the centrifuge separation space, while the mass flow rate of the hydraulic fluid is to be increased so that leakage losses are compensated.

Another drive of the centrifuge drum with mechanical Transmission means and a drive of the extruder screw via a revolving with the centrifuge drum hydraulic motor with variable speed are also in DE 31 16 749 C2 be ^{¬ written} .

However, the use of hydrostatic drive technology has significant disadvantages. On the one hand, the drive energy repeatedly changes the carrier, from electrical to mechanical and hydrostatic back to mechanical, resulting in significant energy losses. This is of great importance due to the very high energy requirements of a decanter centrifuge.

On the other hand there is a risk of leaks in hydraulic systems, in particular in the case of the high pressures required in the area of decanter centrifuges, which necessitates particular precautions in the area of the food industry in order to avoid contaminations.

In addition, a complex and therefore expensive control network is required in order to be able to handle the various media within the drive paths (mechanical, fluidic, hydrostatic, electrical, etc.) and to guide the decanter centrifuge to optimum criteria. The integration into standardized process control systems is made more difficult and expensive by the intermediate fluid mechanics. Due to the many different components, the maintenance and repair of such drives are complex.

In DE 10 2004 034 409 AI is proposed in a drive device for screw centrifuges with a rotating, driven by a motor drum and a coaxial mounted in this screw whose shaft is connected to a drive motor, that the drive motor for the worm from a decoupled from the motor for driving the drum, electric torque motor whose housing is fixedly connected to the drum and rotates with this. In this way it is possible to completely dispense with the use of hydraulic technology for driving the extruder screw.

In electric motors, especially in the high power range, as it is necessary for the drive of extruder screws, but there is often the problem of sufficient heat dissipation.

In this case, insufficient cooling results in the components of the decanter centrifuge being excessively stressed and failing prematurely.

It is therefore an object to provide a decanter centrifuge with improved service life, in which the extruder screw is independent of the centrifuge drum driven and has a freely selectable control range.

To solve the problem is provided according to the invention in a decanter centrifuge of the type mentioned that the motor shaft is designed as a hollow shaft, that at least a portion of the output shaft is arranged in the motor shaft, that the output shaft has a central channel to form a lubricant circuit and that in the lubricant - Circulation a delivery wheel is provided, which receives lubricant from an inner side of the centrifuge drum for supplying the lubricant circuit, wherein the feed wheel against the motor shaft and the output shaft is arranged freely rotatably. Thus, the electric motor can be cooled from the inside via the lubricant flowing through the central channel. The Decoupling the feed wheel from the motor shaft and from the output shaft has the advantage that the feed wheel does not necessarily have to rotate with the rotational speed of the centrifuge drum or the motor. As a result of the decoupling of the delivery wheel from the drive, it is thus possible to avoid centrifugal forces which would otherwise counteract the radially inwardly directed delivery rate of the delivery wheel.

For a compact design, it can be provided that the delivery wheel is rotatably mounted relative to the shaft on a shaft of a drive train comprising the motor shaft and the output shaft. It is particularly advantageous if the feed wheel is rotatably mounted on the output shaft. In order to promote the lubricant absorbed by the feed wheel in the central channel, it can be provided that on a seat of the feed wheel on the or a shaft circumferentially circumferential, closed to the outside ring groove is formed, on the one hand with at least one transport channel of the feed wheel and on the other connected to the central channel. It can be provided that the annular groove is formed on the feed wheel and / or on the shaft. The formation of an annular groove has the advantage that a transport of the lubricant from the transport channel into the central channel at any rotational positions of the feed wheel on the shaft is possible.

To avoid centrifugal forces, which would counteract a conveying of the lubricant, it can be provided that the conveyor wheel is arranged fixed in space. For example, it can be provided for this purpose that claws of a space-fixed fixed to a machine frame hollow shaft engage in recesses of the feed wheel to fix this spatially fixed. In one embodiment of the invention can be provided that the feed wheel has at least one conveying arm, which in a transversely oriented to the longitudinal or conveying direction cross-section at least in a dipped into a formed on the inside of the housing lubricant sump portion a streamlined or teardrop-shaped profile or a having oval profile. In this case, it is particularly favorable if the profile has a length along the flow of lubricant flowing past the delivery arm, which length is greater than the width of the profile transversely to the flow direction. It can also be provided that the flowed surface of the conveying arm has a convex curvature in the profile and / or that the profile in the region of the stall has a tip to prevent eddies. The advantage here is that a trailed by the delivery arm in the lubricant sump furrow quickly closes again, so that the delivery arm does not turn empty after a full turn, but can absorb new lubricant. It can be provided that the lubricant circuit has a pressure relief valve. Thus, bearing seals and the like can be relieved. It is particularly favorable when the pressure relief valve is provided on the delivery wheel.

For example, the pressure limiting valve may be formed by a radially displaceable on the feed wheel, acted upon by a return spring valve body which seals a connected to the annular groove or annular groove monitoring channel tightly, as long as the lubricant pressure in the annular groove does not exceed a preset threshold.

For internal cooling of the electric motor can be provided that the central channel is connected to a preferably cylindrical ring shape having a gap between the motor shaft and the output shaft. This can be set up, for example, via at least one radial passage opening in the output shaft. The advantage here is that the lubricant can be brought into direct contact with the motor shaft, so that a cooling of the rotor of the motor from the inside is possible.

In one embodiment of the invention can be provided that the reduction gear is designed as a circular thrust gear or Zyklogetriebe. Thus, large reductions can be realized in a small space.

It can be provided that the reduction gear at least two eccentrically revolving cams or gears on ^{^} 2weist, which can be arranged offset in rotation to each other for balancing. Thus, a quiet run without tumbling vibrations is achievable. For example, two cams or gears can be offset from one another by 180 °, three cams or gears against each other by 120 ° are arranged rotationally offset or generally N eccentric rotating cams or gears against each other by 360 ° / N rotationally offset from each other. It can be provided that the reduction gear is arranged on the side facing away from the extruder screw side of the electric motor. Thus, the relatively large mass of the electric motor can be arranged as close to the extruder screw, which improves the overall smoothness.

To transmit the output speed of the reduction gear to the output shaft can be provided that the reduction gear rotatably on one with the output shaft connected carrier has a plurality of driving bolts, which engage in recesses at least one eccentrically rotating gear or at least one eccentrically revolving cam for producing a drive connection.

It can be provided that in the carrier at least one lubricant channel for lubricant supply of bearings is formed on the driving pin and connected to the central channel. Thus, the lubricant circuit can be additionally used to lubricate the moving parts of the reduction gear.

By using a separate electric motor for the extruder screw, in addition to the motor for driving the centrifuge drum, these drives can be operated completely independently of each other and without repercussions. The torque of the extruder screw is supported against the centrifuge drum. As there are no hydraulic elements, integration into process control systems as well as maintenance and repair are easily possible. In addition, there is no risk of contamination of the hydraulic oil, as a result of which the decanter centrifuge according to the invention can be used in particular in the food industry or in the pharmaceutical sector. For electrical contacting of the drive for the extruder screw slip rings and brushes are preferably provided in the housing exterior.

The abrasive brushes can preferably stand still. About the slip rings and brushes both the electric drive power and operating signals of the electric motor can be transmitted. The slip rings and brushes are preferably concentric with the motor housing arranged one of the output side of the transmission axially opposite housing part.

In this case, in particular, a slip ring package rotating concentrically with the housing can be provided, which is contacted by means of a plurality of grinding brushes offset in the angular direction. This ensures that there is always a contacting of the electric motor during the rotation, even if vibrations occur in the radial direction.

If the slip ring package runs on a part of the motor housing and is connected by means of resilient contacts with the motor cables, this can be easily replaced if necessary and without further connection assemblies.

The slip rings for contacting the electric motor of the drive for the extruder screw can be mounted on a hollow pin of the motor housing. The invention will now be described in more detail with reference to embodiments, but is not limited to these embodiments. Further embodiments result from combining one or more features of the protection claims with each other and / or with one or more features of the embodiments.

It shows

1 shows a schematic representation of a decanter centrifuge with a device for process control,

Fig. 2 ne sectional view of an axial section of a

Drive for an extruder screw, 3 shows a longitudinal section in the radial plane of a conveyor wheel for lubricant transport,

4 shows an axial section of the feed wheel according to FIG. 3 along A-A, FIG.

5 is a sectional view of an axial section of another embodiment of a drive for the extruder screw,

6 shows a radial section of the permanently excited rotor in the drive according to FIG. 5, FIG.

7 is a radial section of the electric motor in the drive according to FIG. 5, FIG.

Fig. 8 is an axial section of another invention

Drive for the extruder screw and Fig. 9 is a radial section of a drive according to the invention with additional external cooling.

A designated as a whole with 1 decanter centrifuge has, according to FIG. 1, a centrifuge drum 2 and a stored therein, rotatable relative to the centrifuge drum 2 extruder screw 3.

The centrifuge drum 2 is driven by a motor 4 and a belt drive 5. The drive of the motor 4 takes place via an inverter 6.

The extruder screw 3 is moved independently of a drive 7, which rotatably with the centrifuge drum. 2 is connected and is co-rotated with this.

The drive 7 is connected via stationary stationary connection elements 8 with a frequency converter 9. The frequency converter 9 also allows the detection of other operating parameters such as speed, torque, slip, power, temperature, etc. without additional sensors. The control of the frequency converter 9 can via a conventional computer 10, which in turn is connected to a higher-level controller (SCADA).

By using standardized components for the inverters 6, 9 and the computer 10, they can be replaced quickly in the event of a fault or a defect.

FIG. 2 shows an axial section through the drive 7 from FIG. 1.

The drive 7 has an electric motor 11 and a reduction gear 12, which are arranged in a housing 13.

The housing 13 is rotatably connected to the centrifuge drum 2 and is rotated together with this.

The electric motor 11 has an energized stator 14, which is fixed to the inside of the housing 13.

The electric motor 11 further comprises an asynhcronen, provided with short-circuit cage rotor 15, which rotates with the motor shaft 16.

The motor shaft 16 constitutes the driving shaft of the reduction gear 12. The motor shaft 16 is formed as a hollow shaft, and the output shaft 17 of the reduction gear 12 is passed through the motor shaft 16, so that a portion of the output shaft 17 is disposed in the motor shaft 16.

To form a lubricant circuit, an axially extending central channel 18 is formed in the output shaft 17. This central channel 18 may, as shown in Fig. 2, be arranged centrally in the output shaft 17, but there are also off-center configurations possible.

On the output shaft 17, a feed wheel 19 is rotatably mounted with respect to the output shaft 17 on this output shaft 17. This delivery wheel 19 is set up so that lubricant which accumulates in a lubricant sump (not further shown) on the inside 20 of the housing 13 due to the rotation of this housing 13 can receive it and convey it to the central channel 18.

Fig. 3 and Fig. 4 show various views of the feed wheel 19. In detail, Fig. 3 shows a radial section through the feed wheel 19, while Fig. 4 shows an axial section along the line A-A in Fig. 3.

At the seat of the feed wheel 19 on the output shaft 17, an annular collecting channel in the form of an annular groove 21 is formed on the feed wheel 19, which completely rotates the output shaft 17 in the circumferential direction.

The annular groove 21 is connected to two transport channels 22 of the delivery wheel 19, via which the lubricant received from the inside 20 is transported to the annular groove 21. In the assembled position shown in FIG. 2, the annular groove is connected via star-shaped in the output shaft 17 formed radial bores 23 with the central channel 18. Thus, the lubricant adhering to the inner side 20 and forming a lubricant sump can be received by the feed wheel 19 and conveyed via the annular groove 21 into the central channel 18. In this case, the housing 13 rotates while the feed wheel 19 remains fixed in space. In order to keep the feed wheel 19, recesses 24 are formed on the feed wheel 19, in which claws 25 engage in the manner of a dog clutch. The claws 25 are formed at an axial end of a hollow shaft 26 which is rotatably connected at its opposite axial end with a flange 27. The flange 27 is connected via bolts 28 by struts, not shown, with the fixed, stationary machine frame 66 (see Fig. 9). In this way, the feed wheel 19 is prevented from rotating relative to a fixed coordinate system and slides on the output shaft 17 when the output shaft 17 rotates. The feed wheel 19 remains in this way independent of the rotation of the motor shaft 16 or the output shaft 17 fixed in space.

The brushes 30 for electrical contacting of the electric motor 11 and the connection elements 8 forming the cable connection and the protective hood 31 for these connection elements 8 also remain fixed in space.

The hollow shaft 26 receives an oil filter 32, which rotatably is connected to the output shaft 17 and in which the central channel 18 opens. The oil filter 32 is screwed into the output shaft 17, whereby a sliding seal can be omitted.

The thus co-rotated oil filter 32 has radial outlet openings 33 through which lubricant due to the self-rotation of the oil filter 32 is conveyed to the bearing 34 of the output shaft 17.

The aforementioned transport channels 22 are each arranged in a conveying arm 29. The conveying arms extend radially with respect to the center of rotation of a cylindrical base body 34 of the feed wheel 19 and protrude from this cylindrical body 34.

A probe portion is arranged in each case as a collection nozzle 35 to the radially außenseit strength ends of the conveying arms 29, said passage ^¬ channels are directed exclusively tangentially or in the circumferential direction 36 and open into the respective transport channel 22nd

In a region of the conveying arm 29, which dips into the already mentioned lubricant sump on the inside 20 of the housing 13 in the use position, the conveying arm 29 is configured with a cross-section, which in the flow direction of the flowing lubricant, ie in the circumferential direction with respect to the center of rotation of the feed wheel 29, has a length which is greater than the width transversely to this length, ie in the axial direction with respect to the center of rotation of the conveyor wheel 19.

This oval profile forms a streamline shape for the lubricant passing by, through which a furrow formation is largely avoided behind the conveying arm 29 in the lubricant sump.

To relieve the lubricant-supplied bearings and seals a pressure relief valve 37 is formed on the feed wheel 19, which has a valve body 38 which closes by means of a return spring 39 a branched off from the annular groove 21 monitoring channel 40. Excess lubricant can exit the lubricant outlet 72 via this pressure limiting valve 37 and be returned to the mentioned lubricant sump.

The valve body 38 consists of a cylinder with star-shaped projections 41, wherein the valve body 38 is guided by these star-shaped projections 41. Once the valve body 38 is lifted by the lubricant pressure from the monitoring channel 40, lubricant can flow between the star-shaped projections 41 to the outside. In Fig. 2 it is further seen that the central channel 18 is connected via radial passage openings 42 with the gap 43 between the motor shaft 16 and the output shaft 17, so that the promoted by the feed wheel 19 lubricant u.a. in this space 43 is promoted, where he can cool the motor shaft 16 and thus the rotor 15 from the inside.

The reduction gear 12 is designed as a circular thrust gear or Zyklogetriebe and has two eccentrically rotating gears or cams 44 which are mounted on eccentrics 45 by means of needle roller 74.

The eccentrics 45 are formed on the motor shaft 16. Upon rotation of the motor shaft 16 thus the gears or cams 44 are unrolled at a ring gear 46. In this case, an outer toothing may be formed on the toothed wheel or the cam disk 44, which meshes with an internal toothing of the ring gear 46, or recesses and projections may be formed on the toothed wheel or cam disk 44 which interact with webs on the ring gear 46 such that the gear or cam 44 rolls on a rotation of the eccentric 45 on the ring gear 46.

Since in a complete revolution of the eccentric 45, the single gear or the single cam 44 occupies a differential angle with respect to their initial orientation, which is a fraction of a full circle, the rapid rotation of the motor shaft 16 is converted into a slow rotation of the output shaft 17.

To achieve this, a support 47 is rotatably disposed on the output shaft 17, which carries driving pin 48.

The driving pins 48 engage in a respective bore 49 on the gears or cams 44. As a result, the resulting from the mentioned differential angle slow rotational movements are transmitted to the output shaft 17.

Inside the carrier 47, a supply channel 50 is formed, which is fed from the central channel 18 and which supplies the bearings 51 with the driving pin 48 with lubricant.

It should be mentioned that the collecting nozzles 35 are designed as adapted according to shape and inlet cross-section probe parts to the amount of entry after the operating data, the viscosity etc. to determine.

On the housing 13 circumferential cooling fins 53 are formed on the outside relative to the stator 14 and in particular in the region of the stator winding 52, via which the stator 14 can be cooled.

In Fig. 2 it is further apparent that the two gears or cams 44 are mutually offset by 180 ° on the output shaft 17 are arranged so that compensate for the imbalances formed by the eccentric arrangement.

In Fig. 2, the lubricant flow of the lubricant circuit is shown by arrows.

Fig. 2 also shows the electrical connection of the electric motor 11, which is designed in this example with an internal squirrel cage rotor 15 and an external wound stator 14. On a pin 54 there is the slip ring body 55 which rotates with the housing 13 and which is contacted by the grinding brushes 30, which are diametrically opposed in pairs or offset by 90 °. On a contact plate 56, the motor lines 57 are connected, which are guided by a tight passage and the indicated grooves and holes in the stator winding 42.

The apparent in Fig. 3 conveyor arms 29 may be arranged axially offset from each other. In this way it can be avoided that a conveying arm 29 in the furrow drawn by the leading, other conveying arm 29 runs in the lubricant sump. In the reduction gear 12, the output shaft 17 is driven with respect to the motor shaft 16 in the opposite direction of rotation. FIG. 5 shows an axial section of a further drive 7 according to the invention, as it can be used in a decanter centrifuge 1 according to the invention according to FIG. 1.

In this drive 7 are functionally and / or structurally identical components and details with the same reference numerals as in Fig. 2 to 4 and not described again separately.

The drive 7 according to FIG. 5 differs from the drive 7 according to FIGS. 2 to 4 by the design of the electric motor 11.

In the electric motor 11 according to FIG. 5, the permanent magnets 58 are buried in the rotor 15 under the outer surface of the rotor 15.

Fig. 6 shows in a radial section, as two magnets 58 in a V-shaped layer form a pole 59 or 60 with opposite polarity and with concentrated magnetic flux, the tooth winding 52 with a usually three-strand single acting on the teeth 62 of the stator 14 together , This known per se high-pole design results in particularly large torques at a preferred axial length here by the elimination of winding heads.

8 shows an axial section of a third embodiment according to the invention of a drive 7 for the extruder screw 3 from FIG. 1. In Fig. 8 are functionally or constructively to the embodiment of FIG. 2 similar components or details with the same reference numerals and not described again separately. The comments on Fig. 2 apply accordingly.

The embodiment of FIG. 8 differs from the embodiments of FIG. 2 and FIG. 5 in that the ring gear 46 of the reduction gear 12 is not fixed to the housing 13, but via a support plate 73 on the output shaft 17.

The exemplary embodiment according to FIG. 8 differs further from the exemplary embodiments described above in that the carrier 47 of the driver pin 48 is not fixed to the output shaft 17 but to the housing 13.

Thus, it can be achieved that the motor shaft 16 and the output shaft 17 rotate in the same direction during operation.

Fig. 9 shows in an axial section, a solution for supporting the heat release over the outside of the housing 13 of independent inventive importance. Here, the housing 13, which receives the electric motor 11 rotates in the direction of arrow 63. The protective cover 31 with the connecting cable 64 is held by a torque arm 65 which engages the flange 27 on the machine frame 66 fixed space.

An eccentric to the drive 7 and in particular the center of rotation 61, the housing 13 surrounding hood 67 has entry slots, between which in the interior of the hood 67 a Flow channel 70 is formed.

Due to the eccentric arrangement of the hood 67, a constriction or obstruction of the flow channel 70 is formed in the region of the outlet slots 69, through which an air flowing in the flow channel 70 air is passed through the outlet slots 69 to the outside.

Additional, on the inside of the hood 67 formed, radially inwardly projecting baffles 71 enhance this effect.

Due to the rotation of the housing 13, the air located in the flow channel 70 is entrained and promoted from the outlet slots 69 because of the constriction at the end of the flow channel 70.

This creates a negative pressure, through which new air flows through the inlet slots 68 in the flow channel 70. In this way, a cooling flow is generated by the self-rotation of the housing 13 without an additional fan must be present.

In the decanter centrifuge 1 with a centrifuge drum 2 and a rotatably mounted in the centrifuge drum 2 extruder screw 3, wherein the extruder screw 3 is driven by a rotating with the centrifuge drum 2 electric drive 7, it is proposed in the drive train between an electric motor 11 of the drive 7 and Extruder screw 3 to arrange a feed wheel 19, with which lubricant from the inside 20 of a housing 13 of the drive 7 by a relative movement of the feed wheel 19 against the housing 13 in a lubricant circuit for lubrication and cooling of the drive. 7 is promoted, wherein the feed wheel 19 is rotatably mounted slidably on a shaft 16, 17 of the drive train and is kept stationary in space.

Claims

claims

Decanter centrifuge (1) with a motor-driven revolving centrifuge drum (2) and an extruder screw (3) mounted therein, rotatable relative to the centrifuge drum (2), a drive (7) being provided for the extruder screw (3) comprising an electric motor ( 11) and a reduction gear (12) arranged in a housing (13) connected to and rotating with the centrifuge drum (2), a first motor part (stator (14) or rotor (15)) of the electric motor (11 ) is connected to the housing (13) and runs with the centrifuge drum (2) and a second motor part (rotor (15) or stator (14)), which rotates with the motor shaft (16) drives the reduction gear (12), and in that the output shaft (17) of the reduction gear (12) is drive-connected to the extruder screw (3), characterized in that the motor shaft (16) is designed as a hollow shaft, that at least a portion of the output shaft (17) is arranged in the motor shaft (16), that the output shaft (17) has a central channel (18) for forming a lubricant circuit and that in the lubricant circuit a delivery wheel (19) is provided, which lubricant from an inner side (20 ) of the housing (13) for supplying the lubricant circuit receives, wherein the feed wheel (19) relative to the motor shaft (16) and the output shaft (17) is arranged freely rotatably.

Decanter centrifuge (1) according to claim 1, characterized in that the feed wheel (19) on a shaft (16, 17) of the motor shaft (16) and the output shaft (17) comprehensive output line, in particular on the motor shaft (16) or on the output shaft (17), relative to the shaft (16, 17) is rotatably mounted.

Decanter centrifuge (1) according to claim 1 or 2, characterized in that on a seat of the conveyor wheel (19) on the or a shaft (16, 17) in the circumferential direction um ^¬ running, outwardly closed annular groove (21) is formed, which on the one hand with at least one transport channel (22) of the feed wheel (19) and on the other hand with the central channel (18) is connected.

Decanter centrifuge (1) according to one of claims 1 to 3, characterized in that the conveyor wheel (19) is arranged fixed in space.

Decanter centrifuge (1) according to one of claims 1 to 4, characterized in that the conveying wheel (19) has at least one conveying arm (29), which in a transverse to the longitudinal or conveying direction oriented cross-section at least in one on the inside ( 20) of the housing (13) formed dew point section has a streamlined or teardrop-shaped profile or an oval profile. 6. decanter centrifuge (1) according to one of claims 1 to 5, characterized in that the lubricant circuit, in particular the feed wheel (18), a pressure relief valve (37). 7. decanter centrifuge ge (1) according to one of claims 1 to 6, characterized in that the central channel (18) with a preferably cylindrical annular space (43) between the motor shaft (16) and the output shaft (17) is connected, in particular via at least one radial passage opening (42) in the output shaft (17).

8. decanter centrifuge (1) according to one of claims 1 to 7, characterized in that the reduction gear (12) is designed as a circular thrust gear or Zyklogetriebe.

9. decanter centrifuge (1) according to one of claims 1 to 8, characterized in that the reduction gear (12) has at least two eccentrically revolving gears or cams (44), which are arranged offset in rotation to each other for balancing.

10. decanter centrifuge (1) according to one of claims 1 to 9, characterized in that the reduction gear (12) on the side facing away from the extruder screw (3) side of the electric motor (11) is arranged.

11. decanter centrifuge (1) according to one of claims 1 to 10, characterized in that the conveying wheel (19) on the side facing away from the electric motor (11) side of the reduction gear (12) is arranged.

12. decanter centrifuge (1) according to one of claims 1 to 11, characterized in that the reduction gear (12) on a with the output shaft (17) rotatably connected carrier (47) driving pin (48) which in bores (49) of the or an eccentrically revolving gear or the or an eccentrically revolving cam plate (44) engage for the preparation of the drive connection. Decanter centrifuge (1) according to one of claims 1 to 12, characterized in that formed in the carrier (47) at least one supply channel (50) for lubricant supply of bearings (51) on the driving pin (48) and connected to the central channel (18) is.