EP0733406B1 - Centrifuge with a drive unit and an endless transmission means - Google Patents

Description

The invention relates to a centrifuge with an elastically mounted centrifuge drum, a drive unit, which the centrifuge drum with an endless propellant drives, and arranged in the plane of the endless propellant Strain relief means for those caused by the continuous propellant Tensile forces.

For the sugar industry, for example, are continuously operating centrifuges known. The elastic support of the centrifuge drum is said to vibrate isolate the unbalance acting on the drum and resulting from it Vibrations originate. A flexible connection between the Storage of the centrifuge drum and the centrifuge housing decouples the Vibrations of the centrifuge drum so that it does not leak to the environment be passed on. Are preferably used for such an elastic damping Connection vibrating metal rubbers used. Furthermore Endless propellants are used for power transmission, which is known to the Bearing a large lateral force in the form of the drive and preload forces exercise. V-belt drives are usually used. The from the Lateral force resulting from drive and preload forces causes a Relocation of the centrifuge drum. Consequently, the vibration dampers tense, which is essential when using vibrating metal rubbers deteriorated vibration isolation leads and also the life of the Vibration damper greatly shortened.

To solve this problem, it is known the driving and biasing forces of the endless drive by providing an auxiliary shaft from the elastic Decouple the storage of the centrifuge drum. This auxiliary wave is just like the drive unit is fixed, so that the V-belt pulleys have a defined distance. The auxiliary wave leads over a vibration isolating coupling the drive torques in the axial direction the shaft of the elastically supported centrifuge drum. This solution is however, very complex and expensive. The auxiliary wave needs one appropriate console and must be stored at least twice.

Furthermore, the axial alignment of the auxiliary shaft to the shaft of Centrifuge drum for a low-wear run of the centrifuge extremely important. The adjustment work is therefore correspondingly complex.

In addition, US Pat. No. 4,640,770 is operated in batches Centrifugal system known in which a rotatable shaft at one end a gimbal, with at the other end of the Shaft the centrifuge drum is arranged. The wave is in one elongated bearing supported, the bearing and thus the shaft near the Centrifuge drum elastic by means of a support structure on a fixed Base frame is supported. The cardanic bearing on End of the shaft facing away from the centrifuge drum allows the Swiveling of the centrifuge drum connected to the drive shaft two axes of rotation arranged perpendicular to each other and orthogonal to the shaft, however, the centrifuge drum is free to move in lateral directions not possible. That is, deflection movements in axial and to the shaft radial direction can be prevented by the universal joint. The disadvantage is hence that forces generated in the centrifuge drum in the universal joint are positively guided, so that the lateral portion of the deflection forces directly on the bearings of the universal joint act, so that there is increased wear arises.

A similar solution is also presented by EP 0 311 791 A2, in which one Centrifuge with vertical centrifuge spindle also with a cardan joint at the end of the centrifuge spindle facing away from the centrifuge drum is arranged. The drive between the drive unit and the centrifuge spindle takes place via a drive belt. Just as with US 4,640,770 perpendicular to the tensile force direction of the one acting on the spindle axis Drive belt arranged cardan joint axis in the horizontal central plane the spindle-side pulley.

From DE-PS 640 787 a pendulum centrifugal machine with a drive motor connected to the centrifuge drum by a drive belt is known, the drive motor being firmly connected to a support arm on the shaft bearing of the drum. The centrifugal machine and the drive motor are flexibly suspended on all sides. The drive belt tension can be adjusted by moving the drive motor on the support arm. It is disadvantageous that the vibrations originating from the drum are transmitted directly to the drive motor via the support arm, and the drive motor brings large forces into the system as a vibrating mass.
Furthermore, from WO 93/10373 a strain relief device for drive belt drives is known, in which the pretensioning and driving forces on the pulley shafts are absorbed by a pressure rod on both sides of the belt pulleys are screwed on, which have a bearing on the inside in which the corresponding pulley shafts are supported. The shaft distance can be adjusted by turning the elongated sleeve.

From US 3,463,022 is an adjusting device for the tension of a Chain drive known in which a cylinder is provided, the piston rod attacks on a chain tensioner and, for example, with a Shear spring is preloaded in the cylinder chamber. This device is suitable but not for centrifuges.

The object of the invention is to provide a centrifuge with an elastically mounted Centrifuge drum, a drive unit that the centrifuge drum with a Continuous propellant drives, and means for strain relief for those of the To specify endless propellants caused by the Centrifuge drum has all degrees of freedom.

This problem is solved in that the means for strain relief between deflecting means belonging to the endless propellant are arranged and a have elastic thrust element.

Through this strain relief device, the driving and biasing forces of the endless propellant compensated by a counterforce. Consequently the elastic mounting of the centrifuge drum is not tense, so that too no shifting of the rotating drum to the stationary centrifuge inlet arises. Thus the service life of the elastic bearing of the centrifuge drum elevated. In addition, simple vibration dampers such. B. Vibrating metal rubbers can be used. The fact that the wave of Centrifuge drum not at a point in space, for example by a Cardan joint, is fixed, up and down movements or lateral Shifts are not necessarily hindered, but cushioned elastically. The centrifuge drum is in all on the elastic vibration dampers Direction of movement can be deflected elastically. In particular, the Swing the centrifuge drum up and down due to imbalance or shift laterally. The wear on the bearing elements of the This reduces the centrifuge drum.

The strain relief device arranged according to the invention allows one Safe setting and re-tensioning of the endless propellant. Across from conventional constructions with a second shaft can reduce the overall height be significantly reduced. This not only reduces costs and reduces the space requirement of the entire system, and operation is simplified, since the Accessibility from above for the entire centrifuge is significantly improved.

The strain relief acts in the plane of the endless propellant, the line of action preferably aligned with the input and output shafts. So they work Strain relief means exactly that generated by the endless propellant Drive and biasing forces counter without any further tension or Tipping moment arises. The elastic suspension of the centrifuge drum is therefore not unilaterally loaded even during centrifuge operation, so that the service life of the vibration damper is extended. The elastic Thrust element supports the drive and generated by the endless propellant Preload force is released elastically and thus decouples the centrifuge drum vibrationally from the drive.

If the endless propellant is a belt drive, it is a particularly good one Decoupling of the centrifuge drum from the environment is achieved. A belt drive also works on the centrifuge drum in the event of imbalance and vibrations trouble-free.

Characterized in that the elastic thrust element or at least one compression spring Compression spring package, preferably designed as coil springs, or a Has rubber spring, an ideal vibration decoupling of the drive unit reached by the centrifuge drum. The compression spring or the compression spring assembly is generated those to compensate for the driving and preloading forces of the endless traction means required counterforce.

A compression spring package is the most compact version, which consequently takes up the most space can reduce as far as possible.

Alternatively, rubber springs would have the advantage of being self-damping different spring stiffness from the areas left / right on the one hand and Avoid front / rear on the other hand. Have both preferred alternatives also the advantage of not needing a guide or additional elements that the Could otherwise restrict freedom of movement.

Characterized in that the strain relief device has a push rod, a End of the push rod, preferably adjustable in the axial direction, on the Drive unit is attached and the other end of the push rod over the elastic Thrust element is connected to the elastically mounted centrifuge drum is a ideal adhesion between drive unit and elastically mounted Centrifuge drum reached.

With a longer length of the push rod it may be necessary to attach the push rod intercept an interim storage facility. Preferably, the push rod in the Intermediate storage slidable but secured against rotation, for example by one in one Grooving tongue, held.

For tensioning the endless propellant, especially the V-belt, is the Drive unit can be moved on a console, for example by means of elongated holes, educated. After pretensioning the V-belt, the drive unit is on the Console screwed tight again. The prestressing is preferably carried out via a Adjusting nut on a threaded portion of the push rod on the strain relief device. Thereafter, the average driving force from the drive motor over the V-belt drive is transferred to the centrifuge drum by another Biasing the elastic push element on the threaded portion of the Push rod of the strain relief device can be preset. So that's it elastically supported centrifuge drum during centrifuge operation in the essentially in their zero position, d. H. is the elastic support of the centrifuge drum tension-free and has an ideal vibration-decoupling effect.

A preferred embodiment is described below with reference to the drawing described in detail.

Fig. 1

eine Seitenansicht, teils geschnitten, des erfindungsgemäßen Zentrifugenantriebs und

Fig. 2

eine Draufsicht auf den Zentrifugenantrieb gemäß Fig. 1.

It shows

Fig. 1

a side view, partly in section, of the centrifuge drive according to the invention and

Fig. 2

2 shows a plan view of the centrifuge drive according to FIG. 1.

Fig. 1 shows a part of a continuously running centrifuge with an elastic stored centrifuge drum 11 and a drive unit 12, which by means of a Electric motor 13 and a V-belt pulley 14 attached to its shaft a V-belt 16 a V-belt pulley 15 which is fixed to the bearing shaft Centrifuge drum 11 is connected drives. The centrifuge drum 11 is rotatable held on a centrifuge drum base plate 21. The Centrifuge drum base plate 21 is over vibrating metal rubbers 17 with a Base plate 20 connected. The drive unit 12 is fixed via a motor base plate 2, however adjustable via elongated holes, by means of screws 18 with the base plate 20 connected.

Exactly in the connecting line of the two deflection points of the V-belt 16, i. H. in the cutting line through the two axes of the V-belt pulleys 14 and 15 defined plane with the plane spanned by the V-belt 16 is a Strain relief device 19 arranged. The strain relief device 19 exists from a push rod 1 and an elastic push element 6, one end of the Push rod 1 with the motor base plate 2 which can be moved in elongated holes Drive unit 12 is connected and its opposite end with a End of the elastic push element 6 is connected. The other end of the elastic push element 6 is with the elastically mounted centrifuge drum base plate 21 connected. The elastic push element 6 consists of a Spring pack of three compression springs arranged parallel to each other.

The elastic thrust element 6 provides the driving and biasing forces of the V-belt opposing counterforce. To set this counterforce is how 2, a threaded section 22 on that of the drive unit 12 facing end of the push rod 1 is provided on the nuts 9, 10th are screwed on to make the push rod 1 adjustable in the axial direction and consequently the spring assembly of the elastic thrust element 6 as desired preload.

To ensure the centered position of the push rod 1 and emigration To avoid push rod is at the end facing away from the drive unit 12 An intermediate bearing 3 is provided in the push rod 1, in which the push rod 1 centers, but is held axially displaceable. The intermediate storage 3 is on the Centrifuge drum base plate 21 attached. At interim storage 3 is one Plain bearing sleeve 4 arranged around the push rod 1 mounted therein easily to keep sliding. The plain bearing sleeve 4 is by means of screws 7, 8 on the intermediate storage 3 attached. In the bore inside the plain bearing sleeve 4 is an axially parallel Groove provided, in which a spring 5, which is also in an axially parallel groove Push rod 1 is inserted, engages. The push rod 1 is thus secured against rotation stored.

The strain relief device of the centrifuge according to the invention is like described below. First, the drive unit 12 by loosening the Screws 18 loosened from the base plate 20. The drive unit 12 is thus with her Motor base plate 2 can be moved along the elongated holes located therein. Then the V-belt 16 loosely placed on the V-belt pulleys 14 and 15. By preloading the elastic thrust element 6 by adjusting the nuts 9, 10 on the Threaded portion 22 of the push rod 1 is around the V-belt pulleys 14 and 15 placed V-belts 16 tensioned.

The now properly pre-tensioned V-belt 16 defines the axial distance of drive unit 12 and centrifuge drum 11. The elastic Vibrating metal rubbers 17 hold the centrifuge drum base plate 21 and thus the Centrifuge drum 11 in its unloaded zero position. The engine base 2 of the Drive unit 12 is in accordance with the bias of the V-belt 16 in the Elongated holes of the motor base plate 2 have been moved on the base plate 20. Now the motor unit 12 or the motor base plate 2 is firmly attached to the base plate 20 Tighten the screws 18 connected.

Then can between the drive unit 12 and centrifuge drum 11 at Operation acting driving force in the strain relief device 19 accordingly be compensated. For this purpose, the elastic push element 6 by twisting the Nuts 9, 10 further tensioned on the threaded portion 22 of the push rod 1, see above that the average driving torque acting in the operating state is balanced can be.

With such a centrifuge, the centrifuge drum 11 is in the Hibernation, d. H. with the centrifuge stopped, no longer in its zero position. However is the centrifuge drum 11 after the start-up process during continuous centrifuge operation in unstressed center or zero position, so that the Vibrating metal rubbers have an ideal vibration damping effect and a long service life to have. The dynamic behavior of the centrifuge is improved because the V-belt pulleys can be precisely aligned with each other and no tilting moment works in storage.

According to the invention that are required to drive the centrifuge drum Belt tensile forces compensated by a resilient counterforce. The counterforce acts in the axis of symmetry of the belt drive between the drive unit and Centrifuge drum. This can be advantageous for those caused by the belt drive Tensioning forces do not act on the elastic centrifuge drum bearing. The The centrifuge drum is therefore in the operating state, i. H. with continuous Centrifuge operation, in unstressed zero position. There is therefore no relocation of the rotating centrifuge drum for stationary centrifuge inlet. Therefore kick no sealing problems between centrifuge drum and centrifuge inlet or Centrifuge housing. There is therefore the possibility of one rotating product distributor with a stationary steam bell, which would hardly be possible without the strain relief according to the invention.

REFERENCE SIGN LIST

1

Push rod

2nd

Motor base plate

3rd

Interim storage

4th

Plain bearing sleeve

5

feather

6

elastic push element

7

screw

8th

screw

9

mother

10th

mother

11

Centrifuge drum

12th

Drive unit

13

Electric motor

14

V-belt pulley

15

V-belt pulley

16

V-belts

17th

Vibrating metal rubber

18th

screw

19th

Strain relief device

20th

Base plate

21

Centrifuge drum base plate

22

Thread section

Claims (8)

1. A centrifuge with a resiliently mounted centrifuge drum (11), a drive unit (12) driving the centrifuge drum with an endless drive means, and means for tension relief arranged in the plane of the endless drive means for the tensile forces produced by the endless drive means, characterized in that the means for tension relief (19) are arranged between reversing means (14, 15) of the endless drive means and comprise a resilient thrust member (6).
2. A centrifuge according to Claim 1, characterized in that the resilient thrust member (6) is provided with at least one compression spring or a stack of compression springs.
3. A centrifuge according to Claim 2, characterized in that the compression spring or the stack of compression springs is formed by helical springs.
4. A centrifuge according to Claim 1, 2 or 3, characterized in that the endless drive means is a belt drive (16).
5. A centrifuge according to Claim 1, 2, 3 or 4, characterized in that the means for tension relief (19) are provided with a connecting rod (1), wherein one end of the connecting rod (1) is secured to the drive unit (12) and the other end of the connecting rod (1) is connected by way of the resilient thrust member (6) to the resiliently mounted centrifuge drum (11).
6. A centrifuge according to Claim 5, characterized in that the connecting rod (1) is adjustable in the axial direction.
7. A centrifuge according to Claim 5 or 6, characterized in that the connecting rod (1) is held in a displaceable manner on an intermediate bearing (3), and preferably in a manner preventing rotation.
8. A centrifuge according to one of Claims 1 to 7, characterized in that the drive unit (12) is displaceable in order to tension the endless drive means.

Images