EP3485977B1 - Centrifuge and swing-out rotor - Google Patents

Description

The present invention relates to a centrifuge according to the preamble of claim 1 and a swing-bucket rotor according to the preamble of claim 8.

Centrifuge rotors are used in centrifuges, in particular laboratory centrifuges, in order to separate the components of samples centrifuged therein using mass inertia. Increasingly higher rotation speeds are used to achieve higher segregation rates. Laboratory centrifuges are centrifuges whose rotors work at preferably at least 3,000, preferably at least 10,000, in particular at least 15,000 revolutions per minute and are mostly placed on tables. In order to be able to place them on a work table, they have in particular a form factor of less than 1 m×1 m×1 m, so their installation space is limited. The device depth is preferably limited to a maximum of 70 cm.

Such centrifuges are used in the fields of medicine, pharmacy, biology and chemistry and the like.

In most cases it is provided that the samples are centrifuged at certain temperatures. For example, samples that contain proteins and similar organic substances must not be overheated, so that the upper temperature limit for such samples is usually around +40°C. On the other hand, certain samples are cooled by default in the +4°C range (water anomaly starts at 3.98°C).

In addition to such predetermined maximum temperatures of, for example, approx. +40°C and standard test temperatures such as +4°C, other standard test temperatures are also provided, such as +11°C, in order to check at this temperature whether the refrigeration system of the centrifuge is regulated below room temperature . On the other hand, for occupational safety reasons, it is necessary to avoid touching elements that have a temperature of greater than or equal to +60°C.

In principle, active and passive systems can be used for temperature control. Active cooling systems have a refrigerant circuit that covers the centrifuge container tempered, which indirectly cools the centrifuge rotor and the sample containers contained therein.

Passive systems are based on exhaust air-supported cooling or ventilation. This air is routed directly past the centrifuge rotor, which results in temperature control. The air is sucked into the centrifuge chamber through openings, whereby the suction takes place automatically through the rotation of the centrifuge rotor.

The samples to be centrifuged are stored in sample containers and these sample containers are driven in rotation by means of a centrifuge rotor. The centrifuge rotors are usually set in rotation by means of a vertical drive shaft that is driven by an electric motor. There are different centrifuge rotors that are used depending on the application. The sample containers can contain the samples directly, or separate sample containers containing the sample are inserted into the sample containers, so that a large number of samples can be centrifuged simultaneously in one sample container.

Very generally, centrifuge rotors are known in the form of fixed-angle rotors and swing-bucket rotors.

If the sample vessels are arranged at a fixed, predetermined angle in the centrifuge rotor, then this is a so-called fixed-angle rotor. Such fixed-angle rotors usually have a lower part and a cover, with the closed state of the cover forming an interior space between the lower part and the cover, in which the sample vessels can be arranged in order to centrifuge the samples in a suitable centrifuge.

In contrast to this, a swing-out rotor is present if there is at least one hanger in the centrifuge rotor which can swing out from a vertical position to a horizontal position depending on the rotational speed of the centrifuge rotor. The hanger is mounted on a rotor body so that it can swing out. Such hangers are usually designed as centrifuge buckets. However, hangers are also known in which the sample container itself is provided with appropriate coupling means for coupling to the centrifuge rotor and is thus held in the centrifuge rotor so that it can swing out.

In the context of the present invention, “suspension” is therefore understood not only as a holder for sample containers, but also as sample containers that are mounted such that they can swing out.
The present invention is based on such swing-bucket rotors.

For connection to the centrifuge, the swing-bucket rotor is usually provided with a hub which can be coupled to the motor-driven drive shaft of the centrifuge. The hangers of the swing-bucket rotor usually have a lower part that is closed by a cover. The lid of the hanger is designed so that it can normally be closed with the lower part. However, hangers are also known which do not have a cover.

Usually there is an aerosol-tight seal between the cover and the base. The aerosol-tight seal allows the carriers to be easily transported and manipulated without the risk of the samples contaminating the centrifuge or the environment.

The closure between the lid and the base can be designed in different ways.

A disadvantage of such swing-bucket rotors is that they take up a relatively large amount of space due to the pivoting of the hanger that occurs during swing-out, so that the centrifuges used for centrifuging must be dimensioned relatively large compared to fixed-angle rotors.

The U.S. 3,028,075 A describes a centrifuge with a swing-bucket rotor having six trunnion rings. These trunnion rings are mounted on bolts, allowing them to oscillate in a radial plane. Within the trunnion ring there are sample holders, which are mounted horizontally pivotable relative to the trunnion ring via bolts, the pivotability taking place here in a tangential plane. There are also recesses for the bearing journal rings.

The DE 10 2006 027 680 A1 shows a swing-out rotor with a swing-out container, which has stops for maximum deflection positions opposite the arms of the centrifuge rotor. For this purpose, the swing-out container has a horizontal stop edge and a inclined running stop edge on and on the rotor arms are corresponding stop edges.

The U.S. 3,377,021 A shows a swing-bucket rotor that has receptacles for sample containers to be suspended. These sample containers have a receiving area for samples that can be closed with a lid.

The U.S. 4,435,168 A shows a centrifuge rotor with swing-out containers, which are rotatably mounted between rotor arms about pivots. The rotor arms have a continuous slot that ends in a recess. Bearing pieces are inserted into this recess, with the two webs of the rotor arm being able to be bent up slightly by means of the slot in order to be able to insert and clamp the bearing pieces.

It is therefore the object of the present invention to design the swing-bucket rotor in such a way that this disadvantage is reduced. In particular, the swing-bucket rotor should require less installation space with the same load capacity (ie sample quantity to be taken up). The centrifuge provided with the swing-bucket rotor should preferably be able to have smaller dimensions or, with the same dimensions, be able to take up a larger sample quantity.

This object is achieved with the centrifuge according to claim 1 according to the invention and the swing-bucket rotor according to claim 8 according to the invention. Advantageous developments are specified in the dependent claims and in the following description together with the figures.

The inventors recognized that this task can be solved in a surprising manner in a particularly simple manner if recesses are provided in the swing-bucket rotor, into which at least parts of the hanger and/or sample containers mounted therein can dip when the hanger swings out. As a result, the swing-bucket rotor can be designed much more compactly with the same loading capacity of the hanger. In this context, it can be provided that areas of the cover, areas of the lower part or areas of both the lower part and the cover dip into the recesses when swinging out.

The centrifuge according to the invention, which is in particular a laboratory centrifuge, comprises a swing-bucket rotor driven by drive means, which has one or more hangers, preferably buckets, and a rotor hub for coupling to the drive means, with the hanger being mounted so that it can swing out between two rotor arms of a rotor base body, and is characterized characterized in that the rotor arms have recesses into which the hanger and/or the sample containers mounted therein dip at least partially in the swung-out state.

In an advantageous further development it is provided that the recesses are formed as grooves, in particular as fluting. They can then be introduced into the swing-bucket rotor in a particularly simple manner, for example as part of a forming process when producing the basic rotor body.

In an advantageous development it is provided that the recesses are rounded. As a result, only the smallest possible recess is required for immersing the hanger.

In an advantageous development, it is provided that the recesses extend over a length of the rotor arm that is shorter than the distance between the rotor hub and the mounting of the hangers. Then the stability of the swing-bucket rotor is guaranteed even in the limit range.

In an advantageous further development it is provided that the recesses extend over a height of the rotor arm which is less than the height of the rotor arm at the location of the recess, the recesses being delimited in particular by upper and lower webs. Then the stability of the swing-bucket rotor is guaranteed even in the limit range.

In an advantageous further development it is provided that two recesses arranged on different sides of a rotor arm are connected by an opening. For example, the connected cavities may have the cross-sectional shape of a diabolos with a central passage. As a result, the compactness and mass reduction of the swing-bucket rotor can be further improved.

In an advantageous further development it is provided that the rotor arms are designed with a smaller cross-section at the location of the recess than in areas without a recess. This reduces the inertial mass of the swing-bucket rotor, which reduces the energy requirement when starting centrifugation.

According to the invention, it is provided that the recesses cover a region of the rotor arms which, in relation to the radius of the swing-out rotor, corresponds to half the distance between the axis of rotation of the swing-out rotor and the bearing of the hanger. Then the swing-bucket rotor is particularly compact.

In an advantageous further development it is provided that the swing-bucket rotor has at least three, preferably at least four, rotor arms for at least three, preferably at least four hangers mounted between them. Of course, five or more rotor arms can also be provided in order to store an equal number of hangers in between so that they can swing out.

Independent protection is claimed for the swing-bucket rotor according to the invention for a centrifuge, which can be driven by a drive means of the centrifuge, the swing-bucket rotor having one or more hangers, preferably cups, and a rotor hub for coupling to the drive means, the hanger between two rotor arms of a rotor base body is mounted such that it can swing out, and is characterized in that the rotor arms have recesses into which the hanger and/or the sample container mounted therein at least partially immerse in the swing-out state.

In an advantageous development, the swing-bucket rotor has at least one of the features of the centrifuge according to the invention.

Fig. 1

die erfindungsgemäße Zentrifuge in einer perspektivischen Ansicht,

Fig. 2

den erfindungsgemäßen Ausschwingrotor der erfindungsgemäßen Zentrifuge nach Fig. 1 gemäß einer ersten bevorzugten Ausgestaltung in einer Draufsicht in einem nicht ausgeschwungenen Zustand der Gehänge,

Fig. 3

den erfindungsgemäßen Ausschwingrotor nach Fig. 2 in einer Schnittansicht in einem ausgeschwungenen Zustand der Gehänge,

Fig. 4

den Rotorgrundkörper des erfindungsgemäßen Ausschwingrotors nach Fig. 2 in einer perspektivischen Ansicht,

Fig. 5

den Rotorgrundkörper nach Fig. 4 in einer perspektivischen Schnittansicht,

Fig. 6

den erfindungsgemäßen Ausschwingrotor der erfindungsgemäßen Zentrifuge nach Fig. 1 gemäß einer zweiten bevorzugten Ausgestaltung in einer Schnittansicht in einem ausgeschwungenen Zustand der Gehänge und

Fig. 7

eine Detailansicht des Ausschwingrotors nach Fig. 6 auf die Ausnehmungen mit den darin eintauchenden Probenbehältern.

The features and further advantages of the present invention will become clear below on the basis of the description of two preferred exemplary embodiments in connection with the figures. The following are shown purely schematically:

1

the centrifuge according to the invention in a perspective view,

2

the swing-bucket rotor according to the invention of the centrifuge according to the invention 1 according to a first preferred embodiment in a plan view in a non-swinged-out state of the hangers,

3

the swing-bucket rotor according to the invention 2 in a sectional view with the hangers in a swung-out state,

4

the basic rotor body of the swing-bucket rotor according to the invention 2 in a perspective view,

figure 5

the rotor body 4 in a perspective sectional view,

6

the swing-bucket rotor according to the invention of the centrifuge according to the invention 1 according to a second preferred embodiment in a sectional view in a swung-out state of the hangers and

7

a detailed view of the swing-bucket rotor 6 onto the recesses with the sample containers immersed in them.

In the Figures 1 to 5 the centrifuge 10 according to the invention with the swing-bucket rotor 12 according to the invention inserted therein and designed according to a first preferred embodiment is shown as an example.

It can be seen that the centrifuge 10 is designed as a laboratory centrifuge which has a housing 14 with a cover 16 . The swing-bucket rotor 12 is arranged in the centrifuge container 18 of the centrifuge 10 on a drive shaft (not shown) of a centrifuge motor (not shown).

The swing-bucket rotor 12 has a basic rotor body 20 with a hub 22 which is coupled to the drive shaft via screws 23 . The basic rotor body 20 has four rotor arms 24, which are each offset from one another in the circumferential direction by 90° on the hub 22. The rotor arms 24 open into arm branches 26, on each of which two retaining pins 28 are arranged, the oppositely arranged retaining pins 28, 28' of two oppositely arranged arm branches 26, 26' being aligned in such a way that they lie in one line and thus form a swing-out axis form A.

The hangers 30 are designed as cups 32 with lids 34 . In these cups 32, samples that are included in sample containers or sample carriers and where the sample containers or sample carriers are optionally arranged in adapters (all not shown), are arranged in order to centrifuge them using the centrifuge 10 .

The hangers 30 have pin receptacles 36 which have an upper stop 38 and two lateral guides 40 . The hangers 30 can be arranged on the retaining pins 28 with the aid of these pin receptacles 36 . The upper stops 38 rest on the retaining pins 28 and the lateral guides 40, together with a design of the pin receptacles 36 that fits in relation to the retaining pins 28, form a pivot bearing 41 about the swing-out axis A, so that the hanger 30 about the swing-out axis A from the in 2 non-swing position shown in the in 3 swing out position shown.

The non-swinged-out position, in which the longitudinal axis L of the hanger extends parallel to the axis of rotation D of the swing-out rotor 12, is assumed by the hanger 30 while the swing-out rotor 12 is at a standstill. The swing-out position, in which the longitudinal axis L of the hanger extends perpendicularly to the axis of rotation D of the swing-bucket rotor 12, is assumed by the hanger 30 while the swing-bucket rotor 12 is operating at a sufficient speed.

Starting from the hub 22, the rotor arms 24 have a slightly conically tapering cross section, the thickness B being constant over the entire height H, except for the areas in which the recesses 42 are provided. There, the thickness B' is significantly reduced, as is particularly evident in figure 5 can be seen. These recesses 42 extend over an area that lies halfway between the swing-out axis A and the axis of rotation D in relation to the radius of the swing-out rotor 12 .

The recesses 42 are fluted and rounded and the lids 34 of the cups 32 can dip into them when swung out, as in FIG 3 can be seen.

Due to the fact that the recesses 42 are delimited at the top and bottom by webs 44, a high level of rigidity and stability is ensured even at high speeds of the swing-bucket rotor 12 despite the removal of material.

This special configuration of the swing-bucket rotor 12 with recesses 42 into which the hangers 30 can immerse results in numerous advantages.

On the one hand, the swing-out axes A can be brought closer to the axis of rotation D with an identical hanger 30 . As a result, the centrifuge containers 18 and thus also the centrifuges 10 can be made much more compact because swinging out now requires less installation space.

On the other hand, instead of a more compact design of the centrifuges 10, the dimensions of both the centrifuge container 18 and the basic rotor body 20 can be retained and instead the hangers 30 can be enlarged so that a larger sample quantity can be centrifuged.

In addition, a reduction in the inertial mass of the swing-bucket rotor 12 is associated with the recesses 42, as a result of which the energy expenditure is significantly reduced, especially when the centrifuge 10 is started up.

Even if the cover 34 of the hanger 30 dips into the recess 42 in the exemplary embodiment described, the invention is not restricted to this. The swing-bucket rotor 12 can also be designed in such a way that only the cup 32 itself or the cup 32 and cover 34 together can enter the recess.

In the second preferred embodiment of the swing-bucket rotor 50 according to the invention, however, it is shown that the hanger 52 itself does not have to dip into the recess 42, but it can also be provided that a sample container 54 arranged in the hanger 52, in which a sample 56 is located , Immersed in this recess 42 during swing, as 6 and according to the relevant detailed view 7 can be removed. The installation space is then also made more compact.

It has become clear from the above description that the present invention provides a centrifuge 10 and a swing-bucket rotor 12, 50 with which the installation space within the centrifuge 10 can be used much better.

Reference List

10

centrifuge according to the invention

12

first preferred embodiment of the swing-bucket rotor according to the invention

14

Centrifuge housing 10

16

Centrifuge lid 10

18

Centrifuge bowl 10

20

rotor body

22

hub

23

Screws for coupling the swing-bucket rotor 12 to the drive shaft of the centrifuge 10

24

rotor arms

26, 26'

arm junctions

28, 28'

retaining pins

30

hangers

32

Mug

34

Lid

36

pin recordings

38

upper stop of the pin holders 36

40

Lateral guides of the pin holders 36

41

pivot bearing

42

recesses

44

Webs for the upper and lower delimitation of the recesses 42

50

second preferred embodiment of the swing-bucket rotor according to the invention

52

hangers

54

sample container

56

sample

B

Rotor arm thickness 24

B'

Thickness of the rotor arms 24 in the area of the recesses 42

D

Axis of rotation of the swing-bucket rotor 12

H

Rotor arm height 24

L

hanger longitudinal axis

A

swing axis

Claims (9)

1. Centrifuge (10), in particular laboratory centrifuge, comprising a swing-out rotor (12; 50) which is driven by drive means, has an axis of rotation (D) and has one or more suspended elements (30; 52), preferably buckets (32), which have a suspended element longitudinal axis (L), and a rotor hub (22) for coupling (23) to the drive means, wherein the suspended element (30; 52) is mounted so as to swing out between two rotor arms (24) of a rotor base body, wherein a swung-out state is present in which the suspended element longitudinal axis (L) extends perpendicularly to the axis of rotation (D) of the swing-out rotor (12), wherein the rotor arms (24) comprise recesses (42) into which the suspended element (30) and/or sample containers (54) accommodated therein dip at least in sections in the swung-out state, characterised in that the recesses (42) cover a region of the rotor arms (24) which corresponds, with respect to the radius of the swing-out rotor (12), to half the distance between the axis of rotation (D) of the swing-out rotor (12) and the support (41) of the suspended element (30; 52).
2. Centrifuge (10) according to Claim 1, characterised in that the recesses (42) are formed as grooves, in particular as flutes, and/or in that the recesses (42) are formed to be rounded.
3. Centrifuge (10) according to claim 1 or 2, characterised in that the recesses (42) extend over a length of the rotor arm (24) which is less than the distance between the rotor hub (22) and the support (41) of the suspended elements (30).
4. Centrifuge (10) according to any one of the preceding claims, characterised in that the recesses (42) extend over a height of the rotor arm (24) which is less than the height (H) of the rotor arm (24) at the location of the recess (42), wherein the recesses (42) are delimited in particular by upper and lower webs (44).
5. Centrifuge according to any one of the preceding claims, characterised in that two recesses arranged on different sides of a rotor arm are connected by an opening.
6. Centrifuge (10) according to any one of the preceding claims, characterised in that the rotor arm (24) is designed with a smaller cross-section at the location of the recess (42) than in regions without the recess (42).
7. Centrifuge (10) according to any one of the preceding claims, characterised in that the swing-out rotor (12) has at least three, preferably at least four, rotor arms (24) for at least three, preferably at least four, suspended elements (30) supported between them.
8. Swing-out rotor (12; 50) for a centrifuge (10), which can be driven by a drive means of the centrifuge (10), wherein the swing-out rotor (12; 50) has an axis of rotation (D) and comprises one or more suspended elements (30; 52), preferably buckets (32), and a rotor hub (22) for coupling (23) to the drive means, wherein the suspended element (30; 52) is mounted so as to swing out between two rotor arms (24) of a rotor base body (20), wherein a swung-out state is present in which the suspended element longitudinal axis (L) extends perpendicularly to the axis of rotation (D) of the swing-out rotor (12), wherein the rotor arms (24) comprise recesses (42) into which the suspended element (30) and/or sample containers (54) accommodated therein dip at least in sections in the swung-out state, characterised in that the recesses (42) cover a region of the rotor arms (24) which corresponds, with respect to the radius of the swing-out rotor (12), to half the distance between the axis of rotation (D) of the swing-out rotor (12) and the support (41) of the suspended element (30 ; 52).
9. Swing-out rotor (12; 52) according to claim 8, characterised by the features relating to the swing-out rotor of at least one of claims 2 to 7.

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