Rotor of a centrifuge
Patent Information
- Application Number
- PCT/EP2025/056282
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-03-08
- Filing Date
- 2025-03-07
- Publication Date
- 2025-10-02
AI Technical Summary
Existing centrifuge rotors face issues with containers failing to return to a consistent rest position due to worn lubrication, leading to increased friction and potential sample damage from jerky movements, and existing solutions are complex, hygienically problematic, or introduce additional steps.
The rotor design incorporates magnetic elements, either permanent magnets or magnetizable materials, arranged in the bearing area to facilitate smooth and controlled pivoting, ensuring the container returns to a consistent rest position without axial contact, using perpendicular magnetic attraction.
This design allows for reliable, hygienic, and efficient container alignment without additional steps, preventing sample damage and maintaining smooth operation even with worn lubrication, while avoiding jerky movements.
Smart Images
Figure EP2025056282_02102025_PF_FP_ABST
Abstract
Description
[0001] Rotor of a centrifuge
[0002] The invention relates to a rotor of a centrifuge according to the type specified in the preamble of claim 1 and to a centrifuge according to the type specified in claim 15.
[0003] Centrifuges are well known. A centrifuge comprises a rotor with a rotational axis and at least one container connected to the rotor via associated bearings. The container is mounted in the rotor so that it can pivot about a pivot axis. The bearings for supporting the container in the rotor are usually provided on the sides of the container. A sample holder is inserted into the container, which has several receptacles extending along a receptacle axis. For loading and unloading, the container is pivoted into a rest position. The receptacle axis of the sample holder in the container is aligned parallel to the rotational axis of the rotor. The bearings can each be formed from a bearing journal connected to the container in a rotationally fixed manner and a bearing opening in the rotor. A lubricating film is usually applied to a support area between the bearing journal and the bearing opening, which ensures low-friction pivoting of the container about the pivot axis.
[0004] During the centrifugation cycle, the container pivots around the pivot axis so that the receiving axis of the sample holder inserted into at least one container forms an angle with the rotation axis of the rotor. The container is then in the pivoted operating position. In the rest position, i.e. when the rotor is not rotating, the container is aligned so that the openings of the sample holder receptacles face upwards and the receiving axis is aligned vertically. With extended operating times and thus multiple pivoting between the rest position and the operating position, the lubricating film is reduced over time. This increases friction in the bearing, i.e. between the bearing pin of the container and the bearing opening of the rotor. This means that smooth pivoting of the container in the rotor is no longer possible.The container does not return to its rest position after the centrifugation cycle, so the sample holder's pick-up axis is not aligned parallel to the rotor's rotation axis. However, proper return to the rest position is essential for automated loading and unloading.
[0005] Existing solutions to this problem include additional mechanical components, such as movable pins that approach the container from below in the rest position and align the container horizontally, thus vertically aligning the sample holder's receiving axis. These solutions are technically complex, critical from a hygiene perspective, and increase cycle times due to an additional work step.
[0006] Furthermore, return mechanisms from the pivoted position to the rest position of the container are provided, among others, in the CN°214°320°541 °U, CN°217°341 0 845°U, CN°217 O 888 O 325°U, CN°218 o609 o 891 o U and CN°219 o 003 o 386 oU is known. In these embodiments, a magnet is provided in the container and a magnetizable rotor or another magnet is formed in the rotor. The magnet of the container is arranged in the pivoting plane perpendicular to the pivot axis, i.e. in the area of the container facing the rotor axis, and forms a stop. When the centrifuge is not rotating, the container moves to the stop, thereby establishing a magnetic connection and positive engagement between the container and rotor in the pivoting direction of the container towards the rotor. The container always has a fixed, defined rest position at the stop, which does not change. By forming the magnetic connection at the stop in the pivoting plane perpendicular to the pivot axis, the container is pulled against the stop by the magnet when it is moved into the rest position. The magnets move almost axially towards each other. The magnets lie against one another in the rest position.This results in jerky movements and shaking of the samples in the container. This can alter or damage the samples.
[0007] It is therefore an object of the invention to further develop a rotor of a centrifuge in such a way that, while avoiding the disadvantages mentioned, the container always assumes the same rest position in a process-safe manner, without damaging the sample and without additional work steps, even if the lubricant in the bearing is worn out.
[0008] In a known manner, a rotor for a centrifuge comprises at least one container which is pivotably mounted in the rotor about a pivot axis perpendicular to a pivot plane via a bearing in the rotor and has at least one sample holder which has at least one receptacle extending along a receptacle axis. The container can be pivoted between a horizontal rest position with the receptacle facing upwards and a pivoted operating position. In the rest position, the receptacle axis of the receptacle is aligned perpendicular to the pivot axis. The pivot axis runs perpendicular to a rotor axis about which the rotor is rotatably mounted. The container is laterally connected to at least one rotor arm of the rotor via the bearing. The container has a magnetic element and the rotor has a magnetic element assigned to the magnetic element.
[0009] According to the invention, the magnetic elements of the rotor and the container are arranged in the area of the bearing. The magnetic elements allow for simple and direct influence on the pivoting of the container. This also provides a simple and reliable way of returning at least one container from the pivoted operating position to the rest position using magnetic forces, thus avoiding a stop that would abruptly terminate the pivoting movement. Instead, the container is gently decelerated. Even a possible overshoot does not lead to a jerky movement, since there is no longer a stop.
[0010] Preferably, a gap is provided between the magnetic element of the rotor and the associated magnetic element of the container in the rest position. The magnetic forces of attraction do not act axially to each other, but perpendicular to the longitudinal axes of the magnetic elements. Contact between the magnetic elements and the resulting sudden impact of the container against the rotor is prevented in all states.
[0011] Preferably, the magnetic elements are each permanent magnets, or one magnetic element is a permanent magnet and an associated magnetic element is a magnetizable element. The magnetizable element can also be formed by the container or the rotor. Thus, within the meaning of the invention, a component made of a magnetizable material also forms a magnetic element. Permanent magnets are highly efficient and require little maintenance. This ensures a long service life for the alignment of the container. The interaction of one or more permanent magnets on the container or rotor and the magnetizable element on the other component is easy to implement.
[0012] According to a further advantageous embodiment of the invention, the rotor and the container each have at least one associated magnetic element in the form of a permanent magnet. The magnetic element of the rotor and the magnetic element of the container are aligned with opposite polarity. This ensures a reliable and permanent magnetic interaction.
[0013] Preferably, the rotor is provided with two rotor arms assigned to the container. The container is connected to each rotor arm laterally via a bearing. Mounting the container between and on two rotor arms enables a uniform, stable distribution of the forces acting on the container to the rotor.
[0014] Preferably, the rotor and / or the container each have a plurality of magnetic elements. By providing a plurality of magnetic elements, the elements can be arranged accordingly depending on the shape, size, and arrangement of the container to ensure reliable return of the container from the operating position to the rest position.
[0015] According to a further advantageous embodiment of the invention, the magnetic elements of the container and the rotor are arranged in the region of the two bearings.
[0016] The magnetizable element is preferably made of ferromagnetic material, in particular fine-grain structural steel. This enables a strong magnetic attraction between the magnet and the magnetizable element. Preferably, the rotor itself forms the magnetizable element.
[0017] Preferably, the rotor and / or the container each have several, in particular two, magnetic elements in the area of a bearing. These are arranged symmetrically on the rotor and the container relative to a plane passing through the pivot axis. The magnetic attraction forces of the magnetic elements on the associated magnetizable or magnetic element are thus evenly distributed around the pivot axis. This enables the container to be permanently and precisely aligned from the operating position to the rest position.
[0018] According to a further advantageous embodiment of the invention, the magnetic elements, in particular of the container, are each located on a horizontal axis such that, in the rest position of the container, the horizontal axis is aligned perpendicular to the receiving axis. This arrangement of the magnetic elements ensures that the container can be reliably returned to the horizontally designed rest position. Preferably, in the rest position of the container, the associated magnetic elements of the rotor and the container are aligned to at least 50%, in particular 90%, overlap with one another. This ensures that the magnetic attraction forces due to the overlap of the associated magnetic elements are sufficiently large to securely align the container from the operating position to the rest position.
[0019] According to a further advantageous embodiment of the invention, the container has a bearing journal connected to the container in a rotationally fixed manner, and the rotor has a bearing opening associated with the bearing journal. The bearing journal and the bearing opening form the bearing. In particular, a lubricant, preferably lubricating grease, is introduced into the bearing. This allows for simple mounting of the container. The lubricant enables a low-friction pivoting movement.
[0020] Preferably, the rotor is H-shaped with four rotor arms and two containers arranged between the rotor arms. This rotor design allows for two containers to be easily and securely mounted on the rotor. Furthermore, reliable pivoting of the containers is ensured.
[0021] A magnetic element includes, on the one hand, all types of magnets such as permanent magnets and, on the other hand, magnetizable or magnetized elements.
[0022] A further aspect of the invention relates to a centrifuge comprising a rotor designed as described.
[0023] Further advantages, features and possible applications of the present invention will become apparent from the following description in conjunction with the embodiments shown in the drawings.
[0024] In the description, claims, and drawings, the terms and associated reference symbols used in the list of reference symbols below are used. In the drawings, the following definitions apply:
[0025] Fig. 1 is a perspective view obliquely from above of a rotor with containers, the containers being in the rest position; Fig. 2 is a perspective view obliquely from above of the rotor with containers, the containers being in the operating position;
[0026] Fig. 3 is a side view of the rotor with containers, with the container in the operating position;
[0027] Fig. 4 is a side view of the rotor with containers, with the container in the rest position, and
[0028] Fig. 5 is a side schematic view of the rotor with containers, with the container in the rest position.
[0029] Figures 1 to 5 each show a rotor 12 for a centrifuge. The rotor 12 is connected via two bearings 24a, 24b to two containers 14, which are pivotably mounted in the bearings 24a, 24b about a pivot axis 18.
[0030] Fig. 1 shows a perspective view obliquely from above of the rotor 12 with containers 14, wherein the containers 14 are in a rest position RS.
[0031] The rotor 12 is H-shaped, with four rotor arms 12b being provided, each pair of rotor arms 12b being centrally connected to one another via a connecting arm 12c. The rotor 12 has a rotation axis 12a around which the rotor 12 can rotate in the centrifuge. The rotor 12 is connected to a centrifuge drive via a connecting element 12d in the connecting arm 12c and is rotatable via the drive. In the two opposite, half-open areas of the H-shape, a container 14 is inserted between the rotor arms 12b and is laterally connected to the respective rotor arm 12b via the associated bearing 24a, 24b. The rotation axis 12a is arranged centrally in the connecting arm 12c.
[0032] The containers 14 are rectangular in shape and each have two lateral, oppositely formed side elements 14a and a receiving area 14b. The side elements 14a are essentially eyelet-shaped and extend from the receiving area 14b along the rotation axis 12a. A bearing pin 14c is arranged on the side element 14a, which is part of the bearing 24a, 24b and is connected to the container 14 in a rotationally fixed manner. The containers 14 are connected to the rotor 12 via bearings 24a, 24b, pivotable about the pivot axis 18, via the two associated rotor arms 12b. The bearings 24a, 24b are formed by the bearing pins 14c of the containers 14 and the bearing openings 12e of the rotor arms 12b associated with the bearing pins 14c. The bearing pins 14c are each mounted in the bearing openings 12e.A lubricant, namely lubricating grease, is introduced between the bearing pins 14c and the bearing openings 12e of the rotor arms 12b in order to enable low-friction pivoting of the containers 14 about the pivot axis 18.
[0033] A pivot plane 18a is formed, with the pivot axes 18 aligned perpendicular to the pivot plane 18a. The pivot axes 18 of the two containers 14 are aligned parallel to each other. The pivot plane 18a extends through the rotation axis 12a. The containers 14 are held at a distance from the connecting arm 12c by the rotor arms 12b, so that the container 14 is not blocked in the event of a possible overshoot from the operating position BS beyond the rest position RS.
[0034] A sample holder 16 is inserted into the receiving area 14b of the container 14. The sample holder 16 has several receptacles 16a. Each sample receptacle 16a is assigned a receiving axis 16b, with the receiving axes 16b of each sample holder 16 being parallel to one another and, in the rest position RS, parallel to the rotor axis 12a. Samples can be inserted into each of the receptacles 16a. The sample holder 16 is designed as a microtiter plate.
[0035] The container 14 can assume two positions in the rotor 12: the rest position RS and an operating position BS. In the rest position RS, the container 14 is aligned horizontally, so that the receiving axes 16b of the sample holders 16 are aligned parallel to the rotation axis 12a. In the operating position BS, the containers 14 are each pivoted inward toward the rotation axis 12a of the rotor 12, with the receiving axes 16b each aligned at an acute angle of less than or equal to 90° with the rotation axis 12a in a side view. The containers 14 in Fig. 1 are aligned in the rest position RS.
[0036] Figure 2 shows a perspective view obliquely from above of the rotor 12 with containers 14, with the containers 14 in the operating position BS. The two containers 14 are aligned in the operating position BS. The receiving axes 16b of the inserted sample holders 16 are aligned at an acute angle of 90° to the rotation axis 18 in a side view. The operating position BS is reached during a centrifugation process in a centrifuge.
[0037] Fig. 3 shows a side detail view of the rotor 12 with containers 14, wherein the container 14 shown is aligned in the operating position BS.
[0038] Two circular magnetic elements 20a, 20b are each incorporated into the side elements 14a of the container 14. The magnetic elements 20a, 20b are of identical design and are located on a horizontal axis 22, which is aligned parallel to the underside 14d of the container 14. In the operating position BS, the magnetic elements 20a, 20b are each arranged outside of the rotor 12. The magnetic elements 20a, 20b are each arranged on one side of the pivot axis 18, with the pivot axis 18 being centrally located between the magnetic elements 20a, 20b.
[0039] The magnetic elements 20a, 20b are designed as permanent magnets.
[0040] Fig. 4 shows a side detail view according to Fig. 3, wherein the container 14 shown is aligned in the rest position RS.
[0041] The rotor 12 is made of a ferromagnetic material, namely fine-grain structural steel, and thus forms a magnetizable element. The magnetic elements 20a, 20b interact with the rotor 12 when the containers 14 pivot back from the operating position BS to the rest position RS. This occurs when the centrifuge's centrifugation process is complete and the rotor 12 no longer rotates around the rotation axis 12a, or the rotation speed is significantly slowed.
[0042] In the rest position RS, a gap is formed between the magnetic elements 20a, 20b and the rotor arm 12b of the rotor 12 facing the magnetic elements 20a, 20b. In the rest position RS, the magnetic elements 20a, 20b do not touch the rotor arm 12b of the rotor 12 facing the magnetic elements 20a, 20b.
[0043] Due to the magnetic attraction force of the magnetic elements 20a, 20b and magnetizable areas of the rotor 12, the containers 14 are aligned in the rest position RS. For this purpose, the magnetic elements 20a, 20b and the illustrated side arm 12b of the
[0044] Rotors 12 by approx. 90%.
[0045] By increasing the rotational speed of the centrifuge, the magnetic attraction force between magnetic elements 20a, 20b and the magnetizable areas of the rotor 12 is overcome, so that the containers 14 can pivot from the rest position RS to the operating position BS.
[0046] Fig. 5 shows a side schematic view of the rotor 12 with containers 14, wherein the container 14 shown is in the rest position RS.
[0047] This design of the rotor 12 with containers 14 for a centrifuge enables a simple and reliable return of the containers 14 from the operating position BS to the rest position RS.
[0048] Furthermore, the samples placed in the sample holder 16 are prevented from being influenced too strongly by the recirculation, so that a reliable centrifugation is possible.
[0049] Container 14 on the rotor 12 or the magnetic elements 20a, 20b on the rotor 12 in the
[0050] Rest position RS is avoided in all cases.
[0051] -IQ-
[0052] Reference symbol list
[0053] 12 Rotor
[0054] 12a Axis of rotation of the rotor 12
[0055] 12b Rotor arm of rotor 12
[0056] 12c Connecting arm of the rotor 12
[0057] 12d Connecting element of the rotor 12
[0058] 12e Bearing opening of the side arm 12b of the rotor 12
[0059] 14 containers
[0060] 14a Side element of the container 14
[0061] 14b Container receiving area 14
[0062] 14c Bearing journal container 14
[0063] 14d Bottom of the container 14
[0064] 16 sample holders
[0065] 16a Sample holder 16
[0066] 16b Mounting axis of the sample holder 16
[0067] 18 Swivel axis
[0068] 18a Swivel plane
[0069] 20a first magnetic sub-element
[0070] 20b second magnetic sub-element
[0071] 22 Axis
[0072] 24 bearings in the rotor 12 for the bearing journal 14c of the container 14
[0073] 24a Bearing of the first rotor arm 12b
[0074] 24b Bearing of the second rotor arm 12b
[0075] RS rest position
[0076] BS operating position
Claims
P a t e n t a n s p r ü c h e 1. Rotor (12) for a centrifuge, comprising at least one container (14) pivotably mounted about a pivot axis (18) in the rotor (12) via a bearing (24) with at least one sample holder (16) having at least one receptacle (16a) extending along a receptacle axis (16b), wherein the container (14) is pivotable between a rest position (RS) with an upwardly directed receptacle (16a) and a pivoted operating position (BS), wherein in the rest position (RS) the receptacle axis (16a) of the receptacle (16) is oriented perpendicular to the pivot axis (18), wherein the pivot axis (18) extends perpendicular to a rotor axis (12a) about which the rotor (12) is rotatably mounted, wherein the container (14) is laterally connected to the rotor (12) via at least one rotor arm (12b) of the rotor via the bearing (24), and wherein the container (14) has a magnetic element (20a, 20b) and the rotor (12) has a magnetic element (20a, 20b) associated with the magnetic element (20a,20b), characterized in that the magnetic elements (20a, 20b) of the rotor (12) and the container (14) are arranged in the region of the bearing (24).
2. Rotor according to claim 1, characterized in that a gap is provided between the magnetic element (20a, 20b) of the rotor (12) and the associated magnetic element (20b, 20a) of the container (14) in the rest position (RS).
3. Rotor according to one of the preceding claims, characterized in that the magnetic elements (20a, 20b) are each permanent magnets, or a magnetic element (20a, 20b) is a permanent magnet and an associated magnetic element (20a, 20b) is a magnetizable element.
4. Rotor according to claim 3, characterized in that the rotor (12) and the container (14) each have at least one mutually associated magnetic element (20a, 20b) in the form of a permanent magnet, wherein the magnetic element (20a, 20b) of the rotor (12) and the magnetic element (20b, 20a) of the container (14) are aligned with a reverse polarity to each other.
5. Rotor according to one of the preceding claims, characterized in that the container (14) is arranged at a distance from the rotor (12) in the pivoting range such that an overshoot of the container (14) towards the rotor (12) beyond the rest position (RS) is possible.
6. Rotor according to one of the preceding claims, characterized in that the rotor (12) is provided with two rotor arms (12b) assigned to the container (14), wherein the container (14) is laterally connected to a rotor arm (12b) via a respective bearing (24a, 24b).
7. Rotor according to claim 6, characterized in that the rotor (12) and / or the container (14) each has a plurality of magnetic elements (20a, 20b).
8. Rotor according to claim 6 and 7, characterized in that the magnetic elements (20a, 20b) of the container (14) and / or the rotor (12) are arranged in the region of the two bearings (24a, 24b).
9. Rotor according to one of claims 3 to 8, characterized in that the magnetizable element is made of ferromagnetic material, in particular fine-grain structural steel.
10. Rotor according to one of the preceding claims, characterized in that the rotor (12) and / or the container (14) have a plurality, in particular two, magnetic elements (20a, 20b) in the region of a bearing (24), which are arranged symmetrically on the rotor (12) and / or on the container (14) to a plane through the pivot axis (18).
11. Rotor according to claim 10, characterized in that the magnetic elements (20a, 20b) are each located on a horizontal axis (22) so that in the rest position (RS) of the container (14) the horizontal axis (22) is aligned perpendicular to the receiving axis (16b).
12. Rotor according to one of the preceding claims, characterized in that in the rest position (RS) of the container (14), the mutually associated magnetic elements (20a, 20b) of the rotor (12) and the container (14) are aligned to at least 50%, in particular 90%, in register with each other.
13. Rotor according to one of the preceding claims, characterized in that the container (14) has a bearing journal (14c) connected to the container (14) in a rotationally fixed manner and the rotor (12) has a bearing opening (12e) associated with the bearing journal (14c), and the bearing journal (14c) and the bearing opening (12e) form the bearing (24), in particular a lubricant, in particular lubricating grease, is introduced into the bearing (24).
14. Rotor according to one of the preceding claims, characterized in that the rotor (12) is H-shaped, with four rotor arms (12b) and two containers (14).
15. Centrifuge comprising a rotor (12) according to any one of the preceding claims.