EP3774062B1 - Centrifuge having a drum tool - Google Patents

Description

The present invention relates to a centrifuge with a drum tool according to the preamble of claim 1.

A centrifuge drum, in particular a separator drum, of the generic type has several drum parts. This includes a lower drum part and an upper drum part and, if necessary, a drum locking ring. A screw connection is formed between at least two of these parts. It is important to be able to tighten and loosen these with a tool in order to open or close the drum.

This screw connection is loosened and tightened using an impact wrench adapted to the respective drum, which is usually designed as a ring wrench.

Here, the ring wrench is placed in a form-fitting manner on the locking ring of the drum and then caused to rotate by hitting it with the help of a firing pin or sledgehammer, which loosens (or tightens) the screw connection. The drum is not mechanically fixed during this process. The counter-torque against the impact on the drum locking ring is provided by the frictional moments of the screw connection and the mass moment of inertia of the drum.

The problem that arises from this is discussed in the GB 437 030 described. Due to the required play between the ring wrench and the torque transfer surfaces on the drum locking ring, there is a risk of local plastic deformation of the torque transfer surfaces on the drum locking ring due to an impulse load that results from the sudden introduction of force into the ring wrench. The plastic deformation appears in the form of hammer-like depressions on the torque transmission surfaces. Depending on the frequency of loosening and retightening, there is progressive wear on the torque transmission surfaces, which can be accompanied by increasing burrs on the torque transmission surfaces, which must be minimized.

Approaches to solving this problem can also be found in the DE 2615 058 or the DE 484 735 . However, according to the technical teachings of the two publications, leverage forces are used that act on one side of the screw connection of the drum locking ring, which can still lead to the threads tilting and thus to the screw connection seizing.

Another disadvantage of the proposed solution DE 2615 058 and DE 484 735 is that the drum must be mechanically fixed because the lever mechanism requires a counter torque to the torque of the lever.

The technological background also includes: DE 10 2012 213 821 A1 and the US 5,996,441 A1 called. The DE 10 2012 213 821 A1 discloses a device for the automated production and release of screw connections. The US 5,996,441 A1 discloses an adjustable electric bottle opener.

The US 2012/100 980 A1 discloses the subject matter of the preamble of claim 1.

Based on the prior art, the object of the invention is to provide a centrifuge with a drum tool for a centrifuge drum in which the disadvantages of the prior art are reduced.

The invention solves this problem with the subject matter of claim 1.

A centrifuge, in particular a separator, is created for the centrifugal processing of a flowable product and drum tool, with at least the following features: a rotatable drum which delimits a centrifugal space and wherein the drum has at least two drum parts that can be rotated relative to one another on a thread, the drum tool, which for opening and / or closing the drum by rotating the drum parts screwed together via the thread, the drum tool having at least the following: a holding element that can be attached to one drum part, a driver element that can be attached to the other, relatively rotatable drum part, at least one rotating device for Relative rotation of the holding element relative to the driver element together with the drum parts, the holding element and the driver element each having two or more points of attack for the rotating device, which are arranged symmetrically in such a way that the forces generated by the rotating device generate a torque for relatively rotating the drum parts, but none or none significantly disadvantageous The resulting force is created, which acts on the screwed drum parts on one side (radial and/or axial), so that they cannot tilt during relative rotation.

In this way, tilting of the drum parts screwed together is avoided and the disadvantages described above are easily reduced.

In order to simplify handling, it is provided that the rotating device has one or more length-variable actuators.

The invention is particularly suitable for centrifuges in which the lower drum part and the upper drum part are either screwed directly together or in which a drum locking ring and the upper drum part or the lower drum part are screwed together.

According to a structurally simple variant, the holding element can be designed as a retaining ring and/or the driver element can be designed as a driver ring.

It can further be advantageously and simply provided that the holding element, in particular the holding ring, has two or more support arms on which the points of attack for the rotating device are formed.

In order to easily implement the subject matter of claim 1 structurally, it can be provided that the points of application are arranged offset by 180 ° or by 120 ° or by 90 ° on the holding element, in particular the retaining ring, and on the driver element, in particular the driver ring. Other variants of this type are conceivable.

It can further be provided that one of the length-variable actuators is arranged between corresponding points of engagement of the holding element, in particular of the retaining ring, and of the driver element, in particular of the driver ring. The variable-length actuators can preferably work according to a fluidic operating principle (hydraulic or pneumatic) or according to an electromotive operating principle.

For example, it can be provided that the drum locking ring has an external thread and the lower drum part has a corresponding internal thread.

Handling can be further simplified if the retaining ring can be placed on the lower part of the drum and clamped to it. It can further advantageously be provided that the driver ring can be placed on the locking ring and can be secured to it in a rotationally fixed manner.

From a design perspective, it can advantageously be provided that at least two or more support arms projecting radially outwards are formed on the retaining ring and on the driver ring and that the actuators are placed between corresponding support arms of the retaining ring and the driver ring.

To implement the invention, it can further advantageously be provided that the actuators act on fastening points of the corresponding support arms, with the fastening points on the retaining ring and the fastening points on the support arms each having the same radial distance from the axis of rotation (so that there is a pairwise symmetry) and preferably lie in an axial plane and / or that the actuators are designed the same.

For this purpose, it can advantageously be provided that the support arms also lie in one plane. They can be the same length radially.

The drum tool thus advantageously serves to facilitate and thus simplify the opening and closing process of the drum, especially with regard to occupational safety. With the drum tool, the drum can be advantageously opened using a fluidic operating principle by rotating the drum closure ring in the range of 0.5° to 45° (angular degrees), particularly preferably 2° to 20°, in the opening direction. The drum locking ring can then be unscrewed further by hand.

Further advantageous refinements can be found in the subclaims.

Figur 1:

eine Vorderansicht einer Zentrifugentrommel im Schnitt, ohne die erfindungsgemäße Öffnungs- und/oder Verschlussvorrichtung;

Figur 2:

die Vorderansicht der Zentrifugentrommel im Schnitt aus Fig. 1 mit der erfindungsgemäßen Öffnungs- und/oder Verschlussvorrichtung;

Figur 3:

eine Ausschnittsvergrößerung der Fig. 2, in der das erfindungsgemäße Trommelwerkzeug dargestellt ist;

Figur 4:

eine Draufsicht der Zentrifugentrommel mit dem erfindungsgemäßen Trommelwerkzeug aus Fig. 2

The invention is described in more detail below using exemplary embodiments with reference to the figures. Show it:

Figure 1:

a front view of a centrifuge drum in section, without the opening and/or closing device according to the invention;

Figure 2:

the front view of the centrifuge drum in section Fig. 1 with the opening and/or closing device according to the invention;

Figure 3:

an enlargement of the section Fig. 2 , in which the drum tool according to the invention is shown;

Figure 4:

a top view of the centrifuge drum with the drum tool according to the invention Fig. 2

In Figure 1 a drum 1 of a centrifuge - here as an example of a separator with a vertical axis of rotation - is shown.

The drum 1 has several drum parts. This includes a lower drum part 2 and an upper drum part 3 as well as a drum locking ring 4. A screw connection is formed between at least two of these parts. It is important to be able to tighten and loosen these with a tool in order to open or close the drum.

Here the upper drum part 3 is inserted into the lower drum part 2. It rests there on an inner radial collar 2a of the drum base 2.

A gap is formed between the outer circumference of the conical upper drum part 3 and the inner circumference of the lower drum part 2, which is at least partially cylindrical on the inside. The locking ring 4, which is also cylindrical on the radial outside, is inserted into this gap. The locking ring 4 has an external thread and the lower drum part 2 has a corresponding internal thread (see also Fig. 3 ). The locking ring 4 is screwed into the drum base 2. It rests on the radially outer edge of the upper drum part 3 and holds it in the lower drum part 2.

This is an exemplary type of screw connection. It is essential that a screw connection is formed between two drum parts. If no locking ring is provided, a screw connection can also be formed directly between the upper drum part and the lower drum part. (not shown here). Other such and similar screw connection variants, which are not shown here, can also be implemented.

The drum lock ring 4 points in Fig. 1 and 3 a conical inner surface 7, which corresponds geometrically to a conical outer surface 8 of the drum upper part 2. By screwing the drum locking ring 4 via its external thread 5 into the internal thread 6 of the drum lower part 2, the conical inner surface 7 of the drum locking ring 4 rests against the conical outer surface 8 of the drum upper part 3, so that it is firmly held in the drum lower part 2.

The drum locking ring 4 also has - here on its axial top - circumferentially distributed torque transmission geometries. These are designed here as cup-like depressions 9.

In Fig. 2 the drum 1 is shown with a drum tool 100 according to the invention.

The drum tool 100 has at least one or more rotating devices as well as a holding means and a driving means.

The holding means and the driving means are designed here as a holding ring 101 and a driving ring 109, which have fastening points or means for one or more variable-length actuators.

The retaining ring 101 here has a substantially angular cross section with ring sections 101a and 101b sealed at right angles to one another.

The retaining ring 101 can be placed on the drum radially from the outside with its ring section 101a. In this state, the ring portion 101a is vertically oriented. In this state, the further ring section 101b extends radially outwards from the ring section 101a.

The retaining ring 101 is in Fig. 3 with the ring section 101a on the outer circumference of the drum lower part 2. Here it ends in the vertical direction approximately with the upper end of the lower drum part 2. In this way, a support surface is formed in alignment with an upper axial plane of the drum locking rings 4.

The retaining ring 101 has a plurality of bores 101c which pass vertically through the radially aligned ring section 101b. The retaining ring 101 also has a conical outer surface 102 on its vertically extending ring section 101a. Corresponding to the conical outer surface 102 is a conical inner surface 103 of a clamping ring 104, which can be attached radially from below to the retaining ring 101 and in Fig.3 is attached to it in this way.

The clamping ring 104 has several threaded holes 104a distributed around its circumference, here vertically aligned. These are aligned with the holes 101c. Here screws 105 are screwed vertically from above through the holes 101c into the threaded holes 104a. The screw 105 each has a screw head 105a, which engages in a step or countersink 101d of the bore 101c, which is each formed by the retaining ring 101.

By tightening the screws 105, the clamping ring 104 is pulled in the axial direction with its conical inner surface 103 against the conical outer surface 102 of the retaining ring 101. As a result, the retaining ring 101 experiences on its peripheral surface a radial force F _R directed towards an interior of the drum 1, which leads to a frictional connection of the retaining ring 101 to the lower drum part 2.

Fig. 3 and 4 further show that at least two support arms 107a, 107b extending radially outwards can be formed on the retaining ring 101, offset circumferentially. These rest on the retaining ring 101 and are attached to it.

The attachment of the support arms 107a, b can, for example, be designed as a cohesive connection in the form of a weld seam 108a, 108b or can be done in another way, for example by pins and / or screws.

A driver element lies radially inside of the support arms 107a, b in the same plane as the support arms 107a, b. This can be designed as a driver ring 109. It can have the same axial extent as the support arms 107a, b.

In Fig. 4 the drum tool 100 is shown in a top view. The driver element 109 has at least two - here two - support arms 110a, 110b that extend radially outwards.

The driver element 109 has several driver bolts 106 - here four - which engage vertically - here vertically from above - each in the recesses 9, which the drum locking ring 4 forms here. The driving pins 106 together with the respective recess 9 form a torque transmission device.

One end of an actuator 111a, 111b is arranged on the support arms 110a, 110b. The respective actuator can advantageously be pivotally attached to the respective support arm 110a, 110b. The respective actuator 111a, 111b works here advantageously and simply according to a fluidic operating principle and can each be designed, for example, as a hydraulic cylinder. Both actuators 111a, 111b can be in In a preferred embodiment, it can be designed the same way, so have the same diameter and/or the same stroke and/or the same pressure/pull. The other ends of the respective actuators 111a, 111b are each supported on a corresponding support arm 107a, 107b of the retaining ring 101. The drum tool 100 thus has at least two actuators 111a, 111b, the length of which is variable.

The at least two actuators 111a, 111b or the two hydraulic cylinders thus generate a relative rotation between the support arms 107a, 107b and the corresponding support arms 110a, 110b by changing their length.

This results in a rotating movement of the drum locking ring 4 relative to the drum lower part 2, whereby the screw connection between the drum locking ring 4 or the drum upper part 3 and the drum lower part 2 can be detached and preferably also tightened again.

The two actuators 111a, 111b or the two hydraulic cylinders are advantageously attached to the circumference of the drum 1 or the drum locking ring 4, offset by 180 degrees, so that no one-sided moment acts on the drum locking ring 4 and the screw connection between the drum locking ring 4 or The upper drum part 3 and the lower drum part 2 are excluded. More support arms can also be provided and more actuators, for example three each, which would then be arranged offset by 120°. Further, finer, uniform angular distributions can be implemented accordingly.

The actuators can each be symmetrically and in the same axial plane on the support arms 107a, 107b; Attack 110a, 110b (at their attachment points).

The simultaneous actuation of the hydraulic cylinders causes an advantageously uniform rotational movement of the drum locking ring 4 or the upper drum part 3 relative to the lower drum part 2.

In this way, no resulting torque can act on the lower drum part 2, provided - as explained above - the actuators 111a, 111b are designed the same. The The lower drum part 2 therefore does not have to be fixed against possible rotational movement during the opening process.

If the actuators 111a, 111b or the fluid cylinders are designed as double-acting cylinders, so that the piston rods are both extended and retracted pneumatically or hydraulically, the drum tool 100 is also used in the manner described to close the screw connection of the drum lower part 2 or the Drum upper part 3 and the drum locking ring 4 can be used.

The drum tool 100 advantageously serves to facilitate the opening and closing process of the drum 2, especially with regard to work safety. With the drum tool 100, the drum 1 can be opened using a fluidic operating principle by rotating the drum closure ring in the range from 0.5° to 45° (angular degrees), particularly preferably 2° to 20°, in the opening direction. The drum locking ring can then be unscrewed further by hand.

By turning the drum locking ring 4 in the opening direction, it is raised slightly due to the pitch of the thread 5, 6. This height offset between the drum locking ring 4 and the retaining ring 101 is compensated for by the play within the pivoting fastenings of the actuators.

The pulse-controlled and wear-causing opening process with an impact wrench designed as a ring wrench is completely eliminated.

Reference symbols

1

drum

2

drum base

2a

Federation

3

Drum top

4

Drum lock ring

5

External thread

6

inner thread

7

Inner surface

8th

external surface

9

deepening

100

Drum tool

101

retaining ring

101a

Ring section

101b

Ring section

101c

drilling

101d

grading

102

external surface

103

Inner surface

104

Clamping ring

104a

Threaded hole

105

screw

105a

screw head

106

driving pin

107a, 107b

Support arms

108a, 108b

Weld

109

driving ring

110a, 110b

Support arm

111a, 111b

actuator

FR

Radial force

Claims (14)

1. Centrifuge, in particular a separator, for the centrifugal processing of a flowable product and a drum tool, having at least the following features:

   a. a rotatable drum (1) defining a centrifuge chamber and

   b. wherein the drum (1) has at least two drum parts (2, 3, 4) rotatable relative to one another on a thread,

   c. the drum tool (100), which is designed to open and/or close the drum by rotating the drum parts (2, 3, 4) screwed together via the thread,

   d. wherein the drum tool has at least the following:

   i. a retaining element which can be attached to one drum part (2),

   ii. a driving element which can be attached to the other, relatively rotatable drum part (3, 4),

   iii. at least one rotation device for rotating the retaining element relative to the driving element together with the drum parts (2, 3, 4),

   characterized in that

   e. the retaining element and the driving element each having two or more points of engagement for the rotation device, wherein these points of engagement are arranged symmetrically in such a way that the forces generated by the rotation device produce a torque for the relative rotation of the drum parts, but no resulting force is produced which acts unilaterally on the screwed drum parts, and

   f. the rotation device comprises one or more actuators (111) of variable length.
2. Centrifuge according to claim 1, characterized in that the retaining element is designed as a retaining ring (101) and/or in that the driving element is/are designed as a driving ring (109).
3. Centrifuge according to claim 1 or 2, characterized in that the retaining element, in particular the retaining ring (101), has two or more support arms (107a, 107b) on which the points of engagement for the rotation device are formed.
4. Centrifuge according to claim 1, 2 or 3, characterized in that the points of engagement are arranged on the retaining element, in particular retaining ring (101), and on the driving element, in particular the driving ring (109), each offset by 180° or by 120° or by 90°.
5. Centrifuge according to one of the preceding claims, characterized in that one of the actuators (111) of variable length is arranged in each case between corresponding ones of the points of engagement of the retaining element, in particular the retaining ring (101), and the driving element, in particular the driving ring (109).
6. Centrifuge according to one of the preceding claims, characterized in that the actuators operate according to a fluidic operating principle or according to an electromotive operating principle.
7. Centrifuge according to one of the preceding claims, characterized in that the retaining ring (101) can be placed against the lower drum part (2) and can be tightly clamped to it.
8. Centrifuge according to claim 7, characterized in that the driving ring (109) can be placed on the locking ring (104) and can be fixed to said ring in a rotationally fixed manner.
9. Centrifuge according to claim 8, characterized in that at least two or more radially outwardly projecting support arms (107a, 107b; 110a, 110b) are formed in each case on the retaining ring (101) and on the driving ring (109).
10. Centrifuge according to claim 9, characterized in that the actuators (111a, 111b) are placed between corresponding support arms (107a, 107b; 110a, 110b) of the retaining ring (101) and the driving ring (109).
11. Centrifuge according to claim 10, characterized in that the actuators (111a, 111b) engage on attachment points of the corresponding support arms (107a, 107b; 110a, 110b), which are each designed symmetrically to the axis of rotation and preferably lie in an axial plane.
12. Centrifuge according to one of the preceding claims, characterized in that the actuators (111a, 111b) are of the same design.
13. Centrifuge according to one of the preceding claims, characterized in that the lower drum part (2) and the upper drum part (3) are either directly screwed together or in that a drum locking ring (4) and/or the upper drum part (3) or the lower drum part (2) are screwed together.
14. Centrifuge according to one of the preceding claims, characterized in that the drum locking ring (4) has an external thread (5) and the lower drum part (2) has a corresponding internal thread (6).

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