centrifuge

Abstract

The invention relates to a centrifuge (10), in particular a laboratory centrifuge, comprising a) a rotor (32) for accommodating a container of material to be centrifuged, b) a drive shaft (42), on which the rotor (32) is supported, c) a motor (18), which drives the rotor (32) via the drive shaft (42), d) a bearing unit (44) having a bearing (20, 22, 24; 46, 48, 50, 52, 54, 56; 64, 66, 68), which has a damping element (20a, 22a, 24a; 46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) comprising a spring axis (20e, 22e, 24e; 46e, 48e, 50e; 52e, 54e, 56e; 64e, 66e, 68e), and e) a carrier element (16) for fastening the motor (18) in the centrifuge (10) via the bearing unit (44). The invention is characterized in that at least one damping element is completely composed of metal and is configured as a metal lining (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a), which comprises a wire mesh having elastic properties.

Description

Technical Field

[0001] This invention relates to centrifuges, particularly laboratory centrifuges. Background Technology

[0002] Many different designs of centrifuges are known, especially laboratory centrifuges. Because laboratory space is often limited, there has been a constant effort to develop a device that is as compact as possible. Furthermore, laboratory centrifuges typically load and unload samples from above, so sufficient free space above the device must be available to open the lid.

[0003] Simultaneously, good damping needs to be considered when designing centrifuges to overcome the inevitable imbalances that occur during centrifuge operation. A commonly known method for this purpose is, for example, to support the rotor-carrying motor on damping elements, the spring axes of which are parallel to the longitudinal axis of the motor. These damping elements are typically made primarily of resin / rubber. Such resin / rubber damping elements are reasonably priced and available in a variety of different constructions and materials. These characteristics are clearly defined and documented, meaning that damping elements constructed in this way are widely used. Therefore, such damping elements are used in the redesign or modification of centrifuges. For applications where significant imbalances do not occur during operation, such damping elements are also perfectly adequate.

[0004] This type of centrifuge is also used in fully automated systems. For example, when using dual rotors, the centrifuge is required to have high imbalance compatibility. This phenomenon, for example, exists in rotors loaded with an odd number of samples, resulting in an operating condition (Lauf) where, for example, one rotor is fully loaded while the other is unloaded.

[0005] However, centrifuges are being used to solve increasingly complex tasks. Imbalances that occur during centrifuge operation are therefore becoming increasingly problematic for such complex tasks and processes, as known rubber-based damping elements have proven insufficient in terms of their damping characteristics and range. Existing damping elements can only adequately absorb the generated forces, which adversely affects the process being performed. Furthermore, damping elements are also subject to compression, which shortens their lifespan and that of the centrifuge itself.

[0006] Therefore, attempts have been made to address this problem by arranging the spring axes of the damping elements in different ways relative to the rotor and motor. Furthermore, various different types of damping elements have been connected in series.

[0007] For example, DE 39 22 744 A1 discloses a centrifuge having a rotor containing a container holding material to be centrifuged. The rotor is driven by a drive shaft connected to a motor. The motor, with its drive shaft and rotor, is connected to a support unit having multiple damping elements, each including a spring axis. An integral connection to a load-bearing element is used to secure the motor and components supported by the motor within the centrifuge. The spring axes of these damping elements can be positioned at an acute angle σ relative to the motor's axis of rotation Y. Each damping element is connected to the support unit via a strut. These struts are arranged concentrically with the corresponding spring axes of the damping elements. The support unit includes a load-bearing plate. The damping elements are formed by a helical spring and another damping element in the form of two compensation chambers, with damping fluid flowing between the two compensation chambers through a throttling channel according to the load direction.

[0008] WO 2015 / 128296 A1 sets the spring axis of the damping element at a certain angle and uses the metal leaf spring (equivalent to the connecting piece) as another damping element, in combination with the rubber damping block.

[0009] GB 739 666 A discloses a centrifuge in which a rubber liner serves as a damping element, and an arm damped by frictional resistance serves as another damping element.

[0010] US 1,848,641 A discloses a centrifuge in which a motor is supported in a housing by a strut and a damping element in the form of a spring.

[0011] DE 195 16 904 A1 discloses a laboratory centrifuge with a vibration damping device made of rubber.

[0012] Known measures for damping motors with rotors carried by the motor are not very effective, especially in the 15 to 50 Hz frequency range. However, the aim is to improve both the permissible imbalance of the centrifuge and the damping across the entire frequency range occurring during centrifuge operation, thereby improving the application possibilities of the centrifuge while ensuring safe and reliable operation. Rotor bursting is not permitted, especially not within the critical resonant range. Rotor misalignment must be kept as small as possible. Furthermore, increasing the overall size to take additional measures to improve damping is not allowed.

[0013] Simultaneously, during operation, vibration transmission from the rotating object (i.e., the partially loaded unbalanced rotor) to the support plate connecting the centrifuge housing should be as low as possible. Otherwise, unacceptable noise will occur, and the centrifuge will begin to move, for example, on a laboratory bench due to vibration. Summary of the Invention

[0014] Therefore, the objective of this invention is to improve the centrifuge so as to achieve sufficient damping over the widest possible frequency range while avoiding the aforementioned disadvantages.

[0015] The centrifuge includes a rotor, a container for holding materials to be centrifuged and separated; a drive shaft on which the rotor is supported; a motor that drives the rotor via the drive shaft; a support unit having support members, each support member having a damping element with a spring axis; and a load-bearing element for securing the motor in the centrifuge via the support unit.

[0016] This invention is based on the understanding that known metal gaskets can be used as damping elements in heavy-load applications and harsh environmental conditions because metal gaskets have significantly better damping characteristics over a wide frequency range than damping elements previously known for use in centrifuges.

[0017] Therefore, according to the present invention, at least one damping element is made entirely of metal and is constructed as a metal liner comprising a metal mesh with elastic properties. However, it is first necessary to determine the various parameters of the metal liner for the centrifuge in a complex manner. The frequency-dependent values ​​for damping in the metal liner are not available from the manufacturer of such a metal liner. Therefore, for relatively lightweight centrifuges, especially laboratory centrifuges, complex calculations and measurements are required to design such a metal liner. Thus, all measurements, calculations, and simulations for designing the metal liner for the centrifuge must be performed incrementally for different types of centrifuges. If this has been done and the parameters for the centrifuge have been optimized, the results in terms of damping characteristics over a wide frequency range are outstanding.

[0018] For certain installation situations, it is advantageous for the metal gasket to be constructed in a cylindrical shape. This allows for a space-saving structural design of the metal gasket, taking into account the cross-section of the existing coupling element and / or the surface area required for absorbing forces.

[0019] To cope with different rotor loads, two metal bushings together form a damping element. The first metal bushing reacts to the rotor's offset in the first direction, and the second metal bushing reacts to the rotor's offset in the second direction, especially the offset in the opposite direction to the first direction. This ensures that the metal bushings only bear compressive stress, as they might be damaged or even destroyed under tensile loads.

[0020] According to an advantageous embodiment of the invention, the support unit has at least one support member with a support plate. A first metal liner is disposed on one side of the support plate, and a second metal liner is disposed on the other side of the support plate.

[0021] A guide pin can pass through a first metal gasket that indirectly or directly abuts against a support plate, a support plate, and a second metal gasket that indirectly or directly abuts against a support plate and a load-bearing element. One side of the guide pin is fixedly connected to the load-bearing element. The other side of the guide pin is provided with a head that indirectly or directly abuts against the first metal gasket. The first metal gasket, the support plate, and the second metal gasket are free to move relative to the guide pin. This ensures damping in opposite directions, which is necessary to prevent possible movement in these directions during centrifuge operation; however, the metal gaskets only bear pressure.

[0022] The damping elements of different support members can also be constructed differently, especially the damping element of the first support member is optimized in terms of damping, while the damping element of the second support member is optimized in terms of bearing gravity. For example, the damping element of the first support member may include at least one metal pad, while the damping element of the second support member may include at least resin / rubber.

[0023] The advantage of this design is that the support components with metal pads can be optimized for the damping required by the centrifuge's support unit, while the resin / rubber support components bear the load of the motor with the rotor. Thus, for example, the lower and upper metal pads will bear the same force. This allows the use of metal pads optimized for damping. Furthermore, the load of the motor with the rotor does not need to be considered when designing the metal pads. In principle, smaller, softer metal pads can be used because these do not bear the load of the motor and rotor, and therefore are not preloaded.

[0024] Preferably, the spacing between adjacent damping elements and / or support members relative to the drive axis in the circumferential direction is equal.

[0025] In some implementations, it may be advantageous to arrange at least one spring axis of the damping element perpendicular to the drive shaft.

[0026] As a supplementary or alternative solution, at least one spring axis of the damping element may also be arranged parallel to the drive shaft.

[0027] According to one embodiment of the present invention, a plurality of support members having damping elements are provided. The spring axis of half of the damping elements is arranged perpendicular to the drive shaft, while the spring axis of the other half of the damping elements is arranged parallel to the drive shaft.

[0028] Here, the spring axes of the damping elements are alternately arranged perpendicular to and parallel to the drive shaft.

[0029] Preferably, the damping element allows a maximum offset of less than 2 mm, especially less than 1.5 mm, in the region of the rotor, and / or a maximum offset of less than 1 mm, especially less than 0.9 mm, in the region of the damping element.

[0030] For example, three damping elements can be set up, with their spring axes arranged in the same way.

[0031] According to one embodiment of the invention, a shim, particularly a metal shim, is provided to restrict the damping element on one side in the direction of the spring axis. This shim ensures that the generated force can be applied or transmitted across the entire cross-section of the damping element.

[0032] The shim can completely cover the damping element in the direction of the spring axis.

[0033] To prevent corrosion, the metal gasket is made of steel wire containing chromium and nickel. Therefore, it is made of rust-free steel wire.

[0034] Preferably, the steel wire has a diameter of 0.05 mm to 0.5 mm (inclusive). It has been shown that optimal elastic deformation for the intended purpose can be obtained within this range.

[0035] For example, metal gaskets can be designed with an outer diameter ranging from 12 mm to 50 mm (inclusive).

[0036] Metal gaskets can be constructed, in particular, as hollow cylinders, especially hollow cylinders with an inner diameter of 4 mm to 12 mm.

[0037] To best meet the requirements of the centrifuge during operation, the damping coefficient k of the metal liner at the predetermined excitation frequency is within the following range:

[0038] At an excitation frequency of 1 Hz, the damping coefficient k is between 500 and 8000 Ns / m;

[0039] At an excitation frequency of 10 Hz, the damping coefficient k is between 300 and 5000 Ns / m;

[0040] At an excitation frequency of 20 Hz, the damping coefficient k is between 200 and 2500 Ns / m;

[0041] At an excitation frequency of 50 Hz, the damping coefficient k is between 80 and 1200 N / m;

[0042] At an excitation frequency of 100 Hz, the damping coefficient k is between 40 and 500 Ns / m.

[0043] According to one embodiment of the invention, the stiffness (c) of the metal gasket is in the range of 3 to 300 N / mm.

[0044] The advantages of using metal liners in centrifuges, in addition to the aforementioned damping characteristics, include excellent aging resistance. There is no hardening or creep of the material. When stainless steel is used, it imparts resistance to corrosion from solvents, acids, oils, greases, liquids, and dust. Furthermore, this type of metal liner exhibits high aging resistance. Metal liners have high compatibility with imbalances, require less installation space, and can therefore be positioned relatively close to the motor and rotor within the centrifuge housing. Moreover, installation under load improves operational safety and reliability. Unlike known resin elements that can break under tensile loads, metal liners prevent breakage. Furthermore, the parameters of metal liners remain almost constant throughout their service life. Temperature fluctuations also do not affect the parameters of metal liners. Therefore, they can be used in hot engine compartments without altering the centrifuge's operating characteristics. Attached Figure Description

[0045] Other advantages, features, and application possibilities of the present invention can be seen from the following description in conjunction with the embodiments shown in the accompanying drawings.

[0046] In the specification, claims, and drawings, the terms and related reference numerals used are listed in the reference numeral list below. The drawings are illustrated below:

[0047] Figure 1a A perspective sectional view of a centrifuge having a motor, rotor, safety container (Sicherheitskessel), and damping elements made of rubber according to the prior art is shown.

[0048] Figure 1b The motor, support plate, and damping elements are shown supported within the centrifuge housing. Figure 1a A partial perspective view;

[0049] Figure 1c Show Figure 1a A longitudinal sectional view;

[0050] Figure 1d Show Figure 1c A partial sectional view Z;

[0051] Figure 1e Show Figure 1a Cross-sectional view;

[0052] Figure 1f Showing according to Figure 1e A cross-sectional view from above along line CC;

[0053] Figure 2a A perspective sectional view of a centrifuge having a motor, rotor, safety container and damping element according to a first embodiment of the present invention is shown.

[0054] Figure 2bThis diagram illustrates a motor, support plate, and damping element supported within a centrifuge housing according to a first embodiment of the present invention. Figure 2a A partial perspective view;

[0055] Figure 2c Show Figure 2a A longitudinal sectional view;

[0056] Figure 2d Show Figure 2c A partial sectional view Z;

[0057] Figure 2e Show Figure 2a Cross-sectional view;

[0058] Figure 2f Showing according to Figure 2e A cross-sectional view of the line CC from above;

[0059] Figure 3a A perspective sectional view of a centrifuge according to a second embodiment of the present invention is shown, the centrifuge having a motor, rotor, safety container and damping element as shown in FIG2 and a prior art damping element as shown in FIG1;

[0060] Figure 3b The motor, support plate, and damping elements are shown supported within the centrifuge housing. Figure 3a A partial perspective view;

[0061] Figure 3c Show Figure 3a A longitudinal sectional view;

[0062] Figure 3d Show Figure 3c A partial sectional view Z;

[0063] Figure 3e Show Figure 3a Cross-sectional view;

[0064] Figure 3f Showing according to Figure 3e A cross-sectional view of the line CC from above;

[0065] Figure 4a A perspective sectional view of a centrifuge according to a third embodiment of the present invention is shown, the centrifuge having a motor, a rotor, a safety container, and a damping element constructed according to the prior art and another configuration of FIG1.

[0066] Figure 4b The motor, support plate, and damping elements are shown supported within the centrifuge housing. Figure 4a A partial perspective view;

[0067] Figure 4c Show Figure 4a A longitudinal sectional view;

[0068] Figure 4d Show Figure 4c A partial sectional view Z;

[0069] Figure 4e Show Figure 4a Cross-sectional view;

[0070] Figure 4f Showing according to Figure 4e A cross-sectional view of the line CC from above;

[0071] Figure 5a A perspective sectional view of a centrifuge according to a fourth embodiment of the present invention is shown, the centrifuge having a motor, a rotor, a safety container and a damping element according to another configuration;

[0072] Figure 5b The motor, support plate, and damping elements are shown supported within the centrifuge housing. Figure 5a A partial perspective view;

[0073] Figure 5c Show Figure 5a A longitudinal sectional view;

[0074] Figure 5d Show Figure 5c A partial sectional view Z;

[0075] Figure 5e Show Figure 5a Cross-sectional view;

[0076] Figure 5f Showing according to Figure 5e A cross-sectional view of the line CC from above;

[0077] Figure 6 A graph showing the offset of the motor shaft in the upper part (in the rotor region) and in the lower part (in the support structure region, i.e., in the damping element region); and

[0078] Figure 7 A graph showing the offset of the axis of rotation with a rubber element and a metal pad. Detailed Implementation

[0079] Figures 1 to 5 show different views of five different embodiments of the laboratory centrifuge 10, wherein Figure 1 shows a prior art embodiment, and Figures 2 to 5 show four different embodiments according to the present invention. To better illustrate the essential elements of the invention, not all components of the centrifuge 10 are shown in the figures. Only the components necessary for understanding the invention are shown in the respective figures.

[0080] Figures 1a to 1fAn embodiment of a conventional laboratory centrifuge 10 is shown.

[0081] Inside the centrifuge housing 12, within the internal space 14, the motor 18 is mounted on a base plate 16 via three supports 20, 22, and 24. The base plate 16 has four integrated legs 26 located on its underside, positioned in the corner regions of the base plate 16. The laboratory centrifuge 10 is mounted on, for example, a laboratory bench (not shown) via the legs 26.

[0082] The centrifuge housing 12 encloses the internal space 14 at the top and has a recess 30 concentric with the motor axis 28 through which the rotor 32 can be loaded.

[0083] The centrifuge lid 34 is segmentally fitted into the recess 30, thereby enclosing the internal space 14. During operation of the laboratory centrifuge 10, ambient air flows into the internal space 14 through concentrically arranged vents 36 and another laterally arranged vent 38. For this purpose, the centrifuge lid 34 is a double-shell design, thereby forming a flow channel 34a between the lateral vent 38 and the concentric vent 36. The centrifuge lid 34 is pivotally supported on the centrifuge housing 12 in a conventional manner.

[0084] A concentric recess 30 of the centrifuge housing 12 abuts a safety container 40, which is fixedly connected to the centrifuge housing 12. A drive shaft 42 passes through the safety container 40 via a corresponding hole introduced into the bottom of the safety container 40. A rotor 32 is mounted in a torsion-resistant manner on the drive shaft 42 connected to a motor 18. The rotor 32 is driven by the motor 18 via the drive shaft 42 in a known manner.

[0085] The motor 18 is fixedly mounted and placed in the support unit 44. The support unit 44 is connected to the base plate 16 via support members 20, 22, and 24. For this purpose, the support unit 44 has plate-shaped protrusions 44a, 44b, and 44c, respectively. Specifically, the plate-shaped protrusion 44a is connected to the support member 20, the plate-shaped protrusion 44b is connected to the support member 22, and the plate-shaped protrusion 44c is connected to the support member 24. The support members 20, 22, and 24 are used to position the support unit 44 so that it is spaced at a predetermined distance from the base plate 16.

[0086] The support member 20 has a damping element in the form of a rubber gasket 20a that abuts against the base plate 16. The rubber gasket 20a is constructed as a cylinder. Threaded pins 20b are connected to each end face of the rubber gasket 20a and secured to the base plate 16. The underside of a plate-shaped protrusion 44a abuts against the upper side of the rubber gasket 20a. The support unit 44 is held on the rubber gasket 20a of the support member 20 by a nut 20c, which is screwed onto the bolt 20b and pressed against the upper side of the plate-shaped protrusion 44a. A washer 20d is positioned between the nut 20c and the upper side of the plate-shaped protrusion 44a.

[0087] Supports 22 and 24 are constructed in a corresponding manner.

[0088] The support member 22 has a damping element in the form of a rubber gasket 22a, which abuts against the base plate 16. The rubber gasket 22a is constructed as a cylinder. Threaded pins 22b are connected to the respective end faces of the rubber gasket 22a and secured to the base plate 16. The lower side of a plate-shaped protrusion 44b abuts against the upper side of the rubber gasket 22a. The support unit 44 is held on the rubber gasket 22a of the support member 22 by a nut 22c, which is screwed onto the bolt 22b and presses against the upper side of the plate-shaped protrusion 44b. A washer 22d is positioned between the nut 22c and the upper side of the plate-shaped protrusion 44b.

[0089] The support member 24 has a damping element in the form of a rubber gasket 24a, which abuts against the base plate 16. The rubber gasket 24a is constructed as a cylinder. Threaded pins 24b are connected to the end faces of the rubber gasket 24a and secured to the base plate 16. The lower side of a plate-shaped protrusion 44c abuts against the upper side of the rubber gasket 24a. The support unit 44 is held on the rubber gasket 24a of the support member 24 by a nut 24c, which is screwed onto the bolt 24b and presses against the upper side of the plate-shaped protrusion 44c. A washer 24d is placed between the nut 24c and the upper side of the plate-shaped protrusion 44c.

[0090] Rubber gaskets 20a, 22a, and 24a have spring axes 20e, 22e, and 24e, respectively. The spring axes are the same as the axes of the corresponding bolts 20b, 22b, and 24b and are arranged parallel to the motor axis 28.

[0091] Therefore, the motor 18, as well as the drive shaft 42 and rotor 32, are fully arranged in and supported by the support unit 44. These components are connected to the centrifuge housing 12 via supports 20, 22, and 24. The support unit 44 is supported in the centrifuge housing by rubber gaskets 20a, 22a, and 24a, preventing noise generation. However, the damping characteristics are insufficient.

[0092] Figures 2a to 2fA first embodiment of the laboratory centrifuge 10 according to the present invention is shown. The same reference numerals are used for the same parts hereinafter. Furthermore, only the differences from existing embodiments are discussed.

[0093] Referring to the embodiment shown in Figure 1, this embodiment includes different support members 46, 48, and 50. Plate-shaped protrusions 44a, 44b, and 44c are located on the first metal gaskets 46a, 48a, and 50a, respectively. These first metal gaskets 46a, 48a, and 50a are pre-tensioned by the mass load of the motor 18 and the rotor 32. Furthermore, the first metal gaskets 46a, 48a, and 50a are configured to be slightly shorter than the rubber gaskets 20a, 22a, and 24a in Figure 1 and are located on the support shoulders 46f, 48f, and 50f. The support shoulders 46f, 48f, and 50f are threadedly connected to the base plate 16. Bolts 46b, 48b, and 50b extend upward from support shoulders 46f, 48f, and 50f, penetrating plate-shaped protrusions 44a, 44b, and 44c, second metal washers 46g, 48g, and 50g having the same design as the first metal washers 46a, 48a, and 50a, and gaskets 46d, 48d, and 50d. Nuts 46c, 48c, and 50c are screwed onto bolts 46b, 48b, and 50b, and pressed against the gaskets and second metal washers 46g, 48g, and 50g. Furthermore, second gaskets 46h, 48h, and 50h are provided between the second metal washers 46g, 48g, and 50g and the support shoulders 46f, 48f, and 50f.

[0094] Therefore, in this way, the first metal pads 46a, 48a, and 50a prevent downward movement, while the second metal pads 46g, 48g, and 50g prevent upward movement. They each bear only pressure, thereby achieving optimal damping characteristics for the metal pads.

[0095] Figures 3a to 3f A second embodiment of the laboratory centrifuge 10 according to the present invention is shown. The same reference numerals are used for the same parts hereinafter. Furthermore, only the differences from the centrifuge of FIG1 and the first embodiment will be discussed.

[0096] This embodiment has a total of six support members, namely the three support members 20, 22, and 24 according to FIG. 1 and the three support members 46, 48, and 50 according to the first embodiment of the present invention. Therefore, the support unit 44 also includes six plate-shaped protrusions 44d, 44e, 44f, 44g, 44h, and 44i. Specifically, protrusion 44d is connected to support member 20, protrusion 44e is connected to support member 22, protrusion 44f is connected to support member 24, protrusion 44g is connected to support member 46, protrusion 44h is connected to support member 48, and protrusion 44i is connected to support member 50. Support members 20, 22, 24, 46, 48, and 50 are arranged concentrically with the motor axis 28 at the same spacing on the base plate 16. In this embodiment, support members 46, 22, 48, 24, 50, and 20 are arranged counterclockwise next to support member 20, 22, 22, 44, 24, 24, and 50, respectively. Thus, the types of support members 20, 22, and 24 according to FIG. 1 are alternately arranged with the types of support members 46, 48, and 50 of the first embodiment of the present invention. This has the advantage that the damping required by the support unit 44 of the centrifuge 10 is essentially achieved by the support members 46, 48, and 50, and the support members 20, 22, and 24 bear the load of the motor with the rotor, thereby the lower and upper metal pads are loaded equally. This allows the use of metal pads optimized for damping. The load of the motor with the rotor need not be considered when designing the metal pads.

[0097] Figures 4a to 4f A third embodiment of the laboratory centrifuge 10 according to the present invention is shown. The same reference numerals are used for the same parts hereinafter. Furthermore, only the differences from the first or second embodiment according to the present invention and from the centrifuge head 10 according to FIG. 1 will be discussed.

[0098] This embodiment, like the second embodiment, has a total of six support members: three support members 20, 22, and 24 according to FIG. 1, and three support members 52, 54, and 56 with horizontal damping. The support unit 44 has three plate-shaped protrusions 44d, 44f, and 44h for each of the three support members 20, 22, and 24. Specifically, protrusion 44d is connected to support member 20, protrusion 44f is connected to support member 22, and protrusion 44h is connected to support member 24.

[0099] Support brackets 44j, 44k, and 44l are provided between the three protrusions 44d, 44f, and 44h of the support unit 44. The support brackets 44j, 44k, and 44l first extend horizontally from the support unit 44, and then extend vertically upwards parallel to the motor axis 28. Relative to the motor axis 28, each support bracket 44j, 44k, and 44l is provided with support plates 58, 60, and 62 extending upwards from the base plate 16 and parallel to the motor axis 28.

[0100] Starting from support plates 58, 60, and 62, second gaskets 52h, 54h, and 56h, second hollow cylindrical metal gaskets 52g, 54g, and 56g, support brackets 44j, 44k, and 44I, first metal gaskets 52a, 54a, and 56a, first gaskets 52d, 54d, and 56d, and nuts 52c, 54c, and 56c are arranged in support members 52, 54, and 56. Bolts 52b, 54b, and 56b are threaded to support plates 58, 60, and 62 and pass through second gaskets 52h, 54h, and 56h, second hollow cylindrical metal gaskets 52g, 54g, and 56g, support brackets 44j, 44k, and 44I, first metal gaskets 52a, 54a, and 56a, and first gaskets 52d, 54d, and 56d. Nuts 52c, 54c, and 56c are screwed onto bolts 52b, 54b, and 56b, and pressed against first washers 52d, 54d, and 56d and first metal gaskets 52a, 54a, and 56a.

[0101] Support members 20, 22, 24, 52, 54, and 56 are arranged concentrically with the motor axis 28 at the same spacing on the base plate 16. Here, in a counterclockwise direction, support member 52 is arranged next to support member 20, support member 22 is arranged next to support member 52, support member 54 is arranged next to support member 22, support member 24 is arranged next to support member 54, support member 56 is arranged next to support member 24, and support member 20 is arranged next to support member 56. Therefore, the first type of support members 20, 22, and 24 of the first embodiment and the third type of support members 52, 54, and 56 are arranged alternately.

[0102] Support members 52, 54, and 56 have spring axes 52e, 54e, and 56e, respectively. The spring axes 52e, 54e, and 56e of the supports 52, 54, and 56 are arranged perpendicular to the motor axis 28. Therefore, these supports react to possible offsets of the motor 18 and rotor 32.

[0103] In this embodiment, damping is also primarily achieved by supports 52, 54, and 56. The metal gaskets here bear only pressure, thus allowing them to exhibit optimal damping characteristics. Rubber gaskets 20a, 22a, and 24a bear the load of the motor with its rotor. This allows the use of metal gaskets optimized for damping.

[0104] Figures 5a to 5f A fourth embodiment of the laboratory centrifuge 10 according to the present invention is shown. The same reference numerals are used for the same parts hereinafter. Furthermore, only the differences from the first, second, or third embodiments of the present invention will be discussed.

[0105] The support unit 44 is configured as in the first embodiment. However, a different support structure is used. Three support members 64, 66, and 68 are provided, which are respectively connected to the plate-shaped protrusions 44a, 44b, and 44c. Support brackets 70, 72, and 74 are provided radially spaced from the plate-shaped protrusions 44a, 44b, and 44c. The support brackets 70, 72, and 74 extend vertically upward from the base plate 16 and then bend horizontally toward the motor axis 28. The support unit 44 is supported by the support brackets 70, 72, and 74. In this embodiment, starting from the protrusions 44a, 44b, and 44c of the plate shape, there are second gaskets 64h, 66h, and 68h, second metal gaskets 64g, 66g, and 68g, support brackets 70, 72, and 74, first metal gaskets 64a, 66a, and 68a, first gaskets 64d, 66d, and 68d, and nuts 64c, 66c, and 68c.

[0106] Bolts 64b, 66b, and 68b are threaded onto the plate-shaped protrusions 44a, 44b, and 44c and pass through the second washers 64h, 66h, and 68h, the second hollow cylindrical metal gaskets 64g, 66g, and 68g, the support brackets 70, 72, and 74, the first metal gaskets 64a, 66a, and 68a, and the first washers 64d, 66d, and 68d. Nuts 64c, 66c, and 68c are screwed onto the bolts 64b, 66b, and 68b and are pressed against the first washers 64d, 66d, and 68d and the first metal gaskets 64a, 66a, and 68a.

[0107] Support members 64, 66, and 68 are respectively provided with spring axes 64e, 66e, and 68e, which are arranged parallel to the motor axis 28. However, the support unit is not located on the support members 20, 24, and 26 in the first embodiment, but is supported by the support members 64, 66, and 68 through support brackets 70, 72, and 74. In this embodiment, first retaining pads 64a, 66a, and 68a are arranged above the support brackets 70, 72, and 74, and second retaining pads 64g, 66g, and 68g are arranged between the plate-shaped protrusions 44a, 44b, and 44c of the support unit 44 and the support brackets 70, 72, and 74.

[0108] In this embodiment, the support unit 44 is suspended and damped in one direction by metal bushings 64a, 66a, 68a and in the other direction by metal bushings 64g, 66g, 68g.

[0109] The metal gasket used in the embodiments of the invention is constructed as a cylinder and has an outer diameter ranging from 12 mm to 50 mm (inclusive). The inner diameter ranges from 4 mm to 12 mm. The gasket completely covers the end face of the metal gasket. Bolts pass through the metal gasket in such a way that the metal gasket remains freely movable relative to the bolts.

[0110] Different implementations can optimize the centrifuge 10 for different applications. The metal liner causes a maximum offset of less than 2 mm, especially less than 1.5 mm, in the height of the rotor. The maximum offset in the height of the metal liner is less than 1 mm, preferably less than 0.9 mm.

[0111] The metal gasket can be formed from steel wire comprising chromium and nickel and constructed to be rust-free. The diameter of the steel wire is in the range of 0.05 mm to 0.5 mm (inclusive).

[0112] The damping coefficient k of the metal bushing used in each embodiment falls within the following range for a given excitation frequency:

[0113] At an excitation frequency of 1 Hz, the damping coefficient k is between 500 and 8000 Ns / m;

[0114] At an excitation frequency of 10 Hz, the damping coefficient k is between 300 and 5000 Ns / m;

[0115] At an excitation frequency of 20 Hz, the damping coefficient k is between 200 and 2500 Ns / m;

[0116] At an excitation frequency of 50 Hz, the damping coefficient k is between 80 and 1200 N / m;

[0117] At an excitation frequency of 100 Hz, the damping coefficient k is between 40 and 500 Ns / m.

[0118] By using the metal gasket instead of or attached to the rubber elements that have been used to date, a large degree of unbalanced compatibility is provided in a small structural space.

[0119] This can be clearly seen by comparing the metal gaskets mentioned above with conventionally used rubber / resin components.

[0120] In the resin elements used, the damping coefficient starts from a very small value and decreases as the excitation frequency increases. From approximately 30 Hz, damping practically ceases to exist; see [link to relevant documentation]. Figure 6 This is a graph showing the offset of the motor axis in the upper part (in the rotor region) and the lower part (in the support structure region, i.e., in the damping element region).

[0121] The spectrum is traversed according to time. See also Figure 7 The rotor accelerates from a stationary state to its rated speed.

[0122] exist Figure 7 As can be seen, by using a metal liner according to the present invention, the offset can be reduced from about 6 mm to about 1 mm. Conversely, in the same centrifuge, with unchanged dimensions (the distance between the rotor and the centrifuge container), the permissible imbalance can be significantly increased.

[0123] List of icon numbers

[0124] 10 Laboratory centrifuge; 12 Centrifuge housing; 14 Internal space of centrifuge housing 12; 16 Base plate; 18 Motor; 20 Support - Left side - Type 1; 20a Metal gasket; 20b Bolt; 20c Nut; 20d Washer; 20e Spring axis; 22 Support - Front - Type 1; 22a Metal gasket; 22b Bolt; 22c Nut; 22d Washer; 22e Spring axis; 24 Support - Right side - Type 1; 24a Metal gasket; 24b Bolt; 24c Nut; 24d Washer; 24e Spring axis; 26 Legs of base plate 16; 28 Motor axis / rotor axis; 30 Recess in centrifuge housing 12; 32 Rotor; 34 Centrifuge cover; 34a Flow channel; 36 Vent - Concentric; 38 Vent - Lateral; 40 Safety container; 42 Drive shaft; 44 Support unit for motor 18; 44a Plate-shaped protrusion - associated with support member 20 or 46; 44b Plate-shaped protrusion - associated with support member 22 or 48; 44c Plate-shaped protrusion - associated with support member 24 or 50; 44d Plate-shaped protrusion - associated with support member 20; 44e Plate-shaped protrusion - associated with support member 46; 44f Plate-shaped protrusion - associated with support member 22; 44g Plate-shaped protrusion - associated with support member 48; 44h Plate-shaped protrusion - associated with support member 24; 44i Plate-shaped protrusion - associated with support member 50; 44j Support bracket - associated with support member 52; 44k Support bracket - associated with support member 54; 44l Support bracket - associated with support member 56; 46 Support member - left side - second type; 46a First metal gasket; 46b Bolt; 46c Nut; 46d First washer; 46e Spring axis; 46f Support shoulder; 46g Second metal gasket; 46h Second washer; 48 Support - Center - Type II; 48a First metal gasket; 48b Bolt; 48c Nut; 48d First washer; 48e Spring axis; 48f Support shoulder; 48g Second metal gasket; 48h Second washer; 50 Support - Right side - Type II; 50a First metal gasket; 50b Bolt; 50c Nut; 50d First washer; 50e Spring axis; 50f Support shoulder; 50g Second metal gasket; 50h Second washer; 52 Support - Left side - Type III; 52a First metal gasket; 52b Bolt; 52c Nut; 52d First washer; 52e Spring axis; 52g Second metal gasket; 52h Second gasket; 54 Support member - center - type 3; 54a First metal gasket; 54b Bolt; 54c Nut; 54d First gasket; 54e Spring axis; 54g Second metal gasket; 54h Second gasket; 56 Support member - right side - type 3;56a First metal gasket; 56b Bolt; 56c Nut; 56d First washer; 56e Spring shaft; 56g Second metal gasket; 56h Second washer; 58 Support plate of support member 52; 60 Support plate of support member 54; 62 Support plate of support member 56; 64 Support member; 64a First metal gasket; 64b Bolt; 64c Nut; 64d First washer; 64e Spring shaft; 64g Second metal gasket; 64h Second washer; 66 Support member; 66a First metal gasket; 66b Bolt; 66c Nut; 66d First washer; 66e Spring shaft; 66g Second metal gasket; 66h Second washer; 68 Support member; 68a First metal gasket; 68b Bolt; 68c Nut; 68d First washer; 68e Spring shaft; 68g Second metal gasket; 68h Second gasket; 70 Support bracket; 72 Support bracket; 74 Support bracket.

Claims

1. A centrifuge (10), comprising: a) Rotor (32), a container for holding the material to be centrifuged; b) Drive shaft (42), on which rotor (32) is supported; c) Motor (18), which drives rotor (32) via drive shaft (42); d) A support unit (44) having support members (46, 48, 50, 52, 54, 56; 64, 66, 68), each support member having a damping element (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) containing a spring axis (46e, 48e, 50e; 52e, 54e, 56e; 64e, 66e, 68e); and e) A support element (16) for fixing the motor (18) in the centrifuge (10) via the support unit (44). The feature is that at least one damping element is made entirely of metal and is constructed as a metal pad (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) comprising a metal mesh with elastic properties. Two metal pads (46a, 48a, 50a; 46g, 48g, 50g, 52a, 54a, 56a; 52g, 54g, 56g; 64a, 66a, 68a; 64g, 66g, 68g) together form a damping element, wherein the first metal pad (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) reacts to the rotor (32) in the first direction of offset, and the second metal pad (46g, 48g, 50g; 52g, 54g, 56g; 64g, 66g, 68g) reacts to the rotor (32) in the second direction opposite to the first direction of offset; The support unit (44) includes at least one support member (46, 48, 50) having a support plate (44a, 44b, 44c; 44d, 44e, 44f; 44g, 44h, 44i; 44j, 44k, 44l), wherein the first metal pad (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) is disposed on one side of the support plate (44a, 44b, 44c; 44d, 44e, 44f; 44g, 44h, 44i; 44j, 44k, 44l), and the second metal pad (46g, 48g, 50g; 52g, 54g, 56g; 64g, 66g, 68g) is disposed on the other side of the support plate (44a, 44b, 44c); A guide pin (46b, 48b, 50b; 52b, 54b, 56b; 64b, 66b, 68b) passes through the first metal gasket (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a), the support plate (44a, 44b, 44c; 44d, 44e, 44f; 44g, 44h, 44i; 44j, 44k, 44l) and the second metal gasket (46g, 48g, 68b). 50g; 52g, 54g, 56g; 64g, 66g, 68g, wherein the first metal gasket indirectly or directly abuts against the support plate (44a, 44b, 44c; 44d, 44e, 44f; 44g, 44h, 44i; 44j, 44k, 44l), and the second metal gasket indirectly or directly abuts against the support plate (44a, 44b, 44c; 44d, 44e, 44f; 44g, 44h, 44l). i; 44j, 44k, 44l) and the bearing element (16), and the guide pins (46b, 48b, 50b; 52b, 54b, 56b; 64b, 66b, 68b) are fixedly connected to the bearing element (16) on one side and have a head on the other side, the head abutting indirectly or directly against the first metal pad (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a). The first metal gasket (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a), the support plate (44a, 44b, 44c), and the second metal gasket (46g, 48g, 50g; 52g, 54g, 56g; 64g, 66g, 68g) are freely movable relative to the guide pin (46b, 48b, 50b; 52b, 54b, 56b; 64b, 66b, 68b).

2. The centrifuge according to claim 1, characterized in that, The metal gaskets (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) are constructed in a cylindrical shape.

3. The centrifuge according to claim 1, characterized in that, The damping elements (20a, 22a, 24a; 46a, 48a, 50a; 52, 54, 56; 64, 66, 68a) of different support members (20, 22, 24; 46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) have different configurations.

4. The centrifuge according to claim 3, characterized in that, The first damping element includes at least one metal pad (46a, 48a, 50a; 52a, 54a, 56a; 64, 66, 68), and the second damping element (20a, 20b, 20c) includes at least resin.

5. The centrifuge according to claim 1, characterized in that, The spacing between adjacent damping elements (20a, 20b, 20c; 46a, 48a, 50a; 52a, 54a, 56a; 64, 66, 68) is equal relative to the drive shaft (42) in the circumferential direction.

6. The centrifuge according to claim 1, characterized in that, At least one spring axis (52e, 54e, 56e) of the damping element is arranged perpendicular to the drive shaft (42).

7. The centrifuge according to claim 1, characterized in that, At least one spring axis (20e, 22e, 24e; 46e, 48a, 50a; 64a, 66a, 68a) of the damping elements (20a, 22a, 24a; 46e, 48e, 50e; 64e, 66e, 68e) is arranged parallel to the drive shaft (42).

8. The centrifuge according to claim 1, characterized in that, The device is provided with multiple support members (20, 22, 24; 52, 54, 56) having damping elements (20a, 22a, 24a; 52a, 54a, 56a), wherein the spring axes (52e, 54e, 56e) of half of the damping elements (52a, 54a, 56a) are arranged perpendicular to the drive shaft (42), and the spring axes (20e, 22e, 24e) of the other half of the damping elements (20a, 22a, 24a) are arranged parallel to the drive shaft (42).

9. The centrifuge according to claim 1, characterized in that, The spring axes (52e, 54e, 56e) of the damping elements (52a, 54a, 56a) are perpendicular to the drive shaft (42), and the spring axes (20e, 22e, 24e) of the damping elements (20a, 22a, 24a) are parallel to the drive shaft (42) and are alternately arranged.

10. The centrifuge according to any one of claims 1-9, characterized in that, The damping elements (46a, 48a, 50a; 52a, 54a, 56a; 62, 64, 66) allow a deflection of less than 2 mm in the region of the rotor (32).

11. The centrifuge according to any one of claims 1-9, characterized in that, The damping elements (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) are allowed to deflect less than 1 mm in the region of the damping elements (20a, 22a, 24a).

12. The centrifuge according to any one of claims 1-9, characterized in that, Three damping elements (20a, 22a, 24a; 46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) are provided, and the spring axes (20e, 22e, 24e; 46e, 48e, 50e; 52e, 54e, 56e; 64e, 66e, 68e) of the three damping elements are arranged in the same manner.

13. The centrifuge according to any one of claims 1-9, characterized in that, A shim (20d, 22d, 24d; 46d, 48d, 50d; 52d, 54d, 56d, 64d, 66d, 68d) is provided to limit the damping element (20a, 22a, 24a; 46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) on one side in the direction of the spring axis (20e, 22e, 24e; 46e, 48e, 50a; 52a, 54a, 56a; 64a, 66a, 68a) on the other side.

14. The centrifuge according to claim 13, characterized in that, The gaskets (20d, 22d, 24d; 46d, 48d, 50d; 52d, 54d, 56d, 64d, 66d, 68d) completely cover the damping elements (20a, 22a, 24a; 46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) in the direction of the spring axis (20e, 22e, 24e; 46e, 48e, 50a; 52a, 54a, 56a; 64a, 66a, 68a).

15. The centrifuge according to any one of claims 1-9, characterized in that, The metal gaskets (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) are formed from steel wire containing chromium and nickel.

16. The centrifuge according to claim 15, characterized in that, The steel wire has a diameter of 0.05 mm to 0.5 mm.

17. The centrifuge according to any one of claims 1-9, characterized in that, The metal gaskets (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) have an outer diameter of 12 mm to 50 mm.

18. The centrifuge according to any one of claims 1-9, characterized in that, The metal gaskets (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) are constructed as hollow cylinders.

19. The centrifuge according to any one of claims 1-9, characterized in that, The damping coefficient k of the metal gaskets (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) is: At an excitation frequency of 1 Hz, the range is between 500 and 8000 Ns / m; At an excitation frequency of 10 Hz, the range is between 300 and 5000 Ns / m; At an excitation frequency of 20 Hz, the range is between 200 and 2500 Ns / m; At an excitation frequency of 50 Hz, the range is between 80 and 1200 Ns / m; At an excitation frequency of 100 Hz, the range is between 40 and 500 Ns / m.

20. The centrifuge according to any one of claims 1-9, characterized in that, The stiffness (c) of the metal gaskets (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) is in the range of 3 N / mm to 300 N / mm.

21. The centrifuge according to claim 3, characterized in that, The damping elements (20a, 22a, 24a; 46a, 48a, 50a; 52, 54, 56; 64, 66, 68a) of different support members (20, 22, 24; 46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) have different configurations. The damping elements (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) of the first support member (46, 48, 50; 52, 54, 56; 64, 66, 68a) are optimized in terms of damping, and the damping elements (20, 22, 24) of the second support member (20, 22, 24) are optimized in terms of bearing gravity.

22. The centrifuge according to claim 10, characterized in that, The damping elements (46a, 48a, 50a; 52a, 54a, 56a; 62, 64, 66) allow a deflection of less than 1.5 mm in the region of the rotor (32).

23. The centrifuge according to claim 11, characterized in that, The damping elements (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) are allowed to deflect less than 0.9 mm in the region of the damping elements (20a, 22a, 24a).

24. The centrifuge according to claim 13, characterized in that, The gaskets (20d, 22d, 24d; 46d, 48d, 50d; 52d, 54d, 56d, 64d, 66d, 68d) are metal gaskets.

25. The centrifuge according to claim 18, characterized in that, The metal gaskets (46a, 48a, 50a; 52a, 54a, 56a; 64a, 66a, 68a) are constructed as hollow cylinders with an inner diameter of 4 mm to 12 mm.

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