Centrifuge with exchangeable rotors

Abstract

A dual centrifuge (10) embodies the following: a driveshaft (16), a rotor (20), which is mounted on the driveshaft (16) and which can be removed axially in a removal direction (E), for a dual centrifuge, having at least one rotational unit (30); an opening (18) in the rotor (20), wherein an end region (16a) of the driveshaft (16) at least engages into said opening; and an additional drive mechanism (32) for the rotational unit or the rotational units (30). The dual centrifuge additionally has a design for operating various additional types of rotors; however, only one rotor (20, 40, 50) can be arranged on the driveshaft (16) at all times. The various rotor types (40, 50) are also adapted to the additional drive mechanism (32) for the rotational units (30) such that the function is not adversely affected. A design for operating at least one angular head rotor (40) and a swing-out rotor (50). For this purpose, the driveshaft (16) and the various rotor types (40, 50) are adapted to each other. The bearing (16), the driveshaft (16), and the various rotor types (40, 50) are adapted to one another such that each non-dual rotor (40, 50) has a geometry that is measured such that when the rotor (40, 50) is mounted, a drive device (32a) of the additional drive mechanism (32) for the rotational units (30) is arranged so as to not contact the mounted rotor (40, 50).

Claims

1. A dual centrifuge, comprising a) driveshaft, b) a first rotor designed as a dual centrifuge rotor which is mounted on the driveshaft and which dual centrifuge rotor can be removed from the driveshaft axially in a removal direction, and having one or plural rotational units, c) an opening in the first rotor which is at least engaged by an end portion of the driveshaft, d) an additional drive mechanism for the one or plural rotational units, and e) at least one second rotor of a type different from the first rotor, wherein only one of the first and second rotors is arranged on the driveshaft at a time, and wherein the second rotor is adapted to the additional drive mechanism for the one or plural rotational units, characterized in that the at least one second rotor is selected from one of an angle head rotor and a swing-out rotor, for which a bearing, the driveshaft and the selected second rotor are adapted to one another, with the selected second rotor having a geometry that is dimensioned such that, after the selected second rotor has been mounted on the driveshaft, the additional drive mechanism for the one or plural rotational units is configured so as not to contact the mounted selected second rotor.

2. A dual centrifuge according to claim 1 wherein at least each the first rotor, and the at least one second rotor has a quick fastener for mounting on and securing the respective first or second rotor to the driveshaft.

3. A dual centrifuge according to claim 2 characterized in that the driveshaft is directly connected to a drive motor, wherein the driveshaft and a motor shaft of the drive motor constitute an integrally formed structural unit of the same material.

4. A dual centrifuge according to claim 1 characterized in that a safety vessel is provided in which the first rotor or the selected second rotor is arranged and into which at least part of the driveshaft projects, wherein the largest diameter of the first rotor or the selected second rotor is 96%, at the most, of the diameter of the safety vessel.

5. A dual centrifuge according to claim 1 characterized in that the driveshaft is designed as a solid shaft.

6. A dual centrifuge according to claim 1 characterized in that the one or plurality of rotational units are each rotatably mounted within a pivot bearing and include a rotary head connected to the pivot bearing via a rotation axis, which rotary head is driven relative to the first rotor by the additional drive mechanism of the centrifuge.

7. A dual centrifuge according to claim 6 characterized in that the first rotor has different transmission ratios provided for the additional drive mechanism.

8. A dual centrifuge according to claim 6 characterized in that the first rotor includes a central gear centrically arranged to form a structural unit therewith, wherein the central gear is connected for co-rotation with a motor and is operatively connected to at least one of the one or plurality of rotational units such that rotation of the first rotor will cause a gear of the connected one of the rotational units to mesh with the central gear.

9. A dual centrifuge according to claim 1 characterized in that the additional drive mechanism includes a gear which is firmly connected to a motor housing and is penetrated by the driveshaft.

10. A dual centrifuge according to claim 9 characterized in that the first rotor includes a central gear centrically arranged to form a structural unit therewith, wherein the central gear is connected for co-rotation with a motor and is operatively connected to at least one of the one or plurality of rotational units such that rotation of the first rotor will cause a gear of the connected one of the rotational units to mesh with the central gear.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Throughout the description, the claims and the drawings, those terms and associated reference signs are used as are listed in the List of Reference Signs below. In the drawings:

(2) FIG. 1 is a lateral sectional view of a dual centrifuge according to the invention with a DC rotor mounted therein;

(3) FIG. 2a is a lateral sectional view of the DC rotor of FIG. 1 and of the portion of the drive motor which is close to the rotor;

(4) FIG. 2b is a lateral sectional view of another inventive embodiment of a DC rotor in the removed condition and of the portion of the drive motor which is close to the rotor;

(5) FIG. 2c is a perspective view of a DC rotor of the type illustrated in FIGS. 1, 2a and 2b mounted on a driveshaft;

(6) FIG. 3a is a lateral sectional view of an angle head rotor mounted on a driveshaft in the manner specified by the present invention and of the portion of the drive motor which is close to the rotor;

(7) FIG. 3b is a perspective view of the angle head rotor illustrated in FIG. 3a mounted on a driveshaft and of the drive motor;

(8) FIG. 4a is a lateral sectional view of a swing-out rotor mounted on a driveshaft in the manner specified by the present invention and of the portion of the drive motor which is close to the rotor, and

(9) FIG. 4b is a perspective view of the swing-out rotor illustrated in FIG. 4a mounted on a driveshaft and of the drive motor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(10) FIG. 1 is a lateral sectional view of a dual centrifuge 10 according to the invention having a DC rotor 20 mounted on a drive motor 12. The dual centrifuge 10 is contained in a housing 11 which comprises an underside 11a and a housing cover 11b which can be opened. When the housing cover 11b is open, the DC rotor 20 can be removed vertically in a removal direction E, starting from the underside 11a.

(11) FIG. 2a is a view of the DC rotor 20 of FIG. 1 mounted on the drive motor 12, which view only shows the portion of the drive motor 12 which is close to the rotor, without the housing 11.

(12) Within the housing 11, the DC rotor 20 is surrounded by a safety vessel 60 which is arranged concentrically with the DC rotor 20. The safety vessel 60 has a circumferential sidewall 60a which is integrally formed with, and made of the same material as, a vessel bottom 60b disposed below the DC rotor 20.

(13) An opening 60c is provided in the vessel bottom 60b which opening 60c is concentric with the sidewall 60a and the drive motor 12 extends through it. The outer circumference of the drive motor 12 and the opening 60c are adapted to one another and provided with a seal (not shown for reasons of clarity). This ensures that in the case of a rotor crash, any flying parts as well as any leakage of material to be centrifuged will be contained within the safety vessel 60.

(14) The drive motor 12 which has a cylindrical motor shaft 14 and which is surrounded by a motor housing 12a, is firmly connected to the underside 11a. The motor shaft 14 is integrally formed with, and made of the same material as, the driveshaft 16, which has an end portion 16a on its free end. The end portion 16a tapers in the removal direction E and partly engages the installed DC rotor 20. A drive axis A extends through the motor shaft 14 and the driveshaft 16. A rotor hub 22 of the DC rotor 20 has an opening 22a which is concentric with the drive axis A and which has parts of its inner contour adapted to the outer contour of the end portion 16a and which also tapers in the removal direction E. This adaptation and the conical taper fix the DC rotor 20 against the removal direction E.

(15) On the side of the DC rotor 20 which faces away from the drive motor 12 a quick fastener 24 is provided which extends into the opening 22a, partially surrounds the end portion 16a of the driveshaft 16 and secures the DC rotor 20 against accidental removal from the driveshaft 16 by means of a push-down mechanism not shown in FIG. 1. Safety devices of this type are well known from the prior art for which reason no further explanations are required here. Instead of a push-down mechanism, a screw which can simply be released by means of an Allen key could also be chosen as a quick-release fastener.

(16) Two openings 26 are provided in the rotor hub 22 which are disposed opposite each other relative to the opening 22a. A rotational unit 30 is mounted in each opening 26. The rotational units 30 comprise a rotational head 34 which is rotatably mounted for supporting sample container receiving units (not shown) for sample containers containing samples to be processed, and a housing 35 in which a bearing 36 for the rotational head 34 is provided. This bearing 36 is in turn penetrated by a bearing shaft of the rotational head 34. This bearing shaft is disposed on the side of the rotational head 34 which faces the housing 35 and is not shown for the reasons of clarity.

(17) The outer profile of the rotational units 30 is rotationally symmetrical and adapted to the inner profile of the opening 26 in the areas associated with the opening 26, and the rotational units 30 have a centric rotational axis R about which they rotate in operation. The rotational units 30 are mounted symmetrically relative to the opening 22a in such a manner that their rotational axes R intersect on the drive axis A above the opening 22a.

(18) An additional drive mechanism 32 is provided for driving the rotational units 30 which mechanism 32 comprises a stationary central gear 32a as well as circumferential toothing 32b on either rotational unit 30. The central gear 32a is concentric with the drive axis A and disposed on the side of the motor housing 12a which faces the DC rotor 20 in such a manner that it surrounds the driveshaft 14. Upon rotation of the DC rotor 20, the teeth of the toothing 32b will mesh with the stationary central gear 32a, thus causing the rotational units 30 to rotate as the DC rotor 20 rotates in operation.

(19) The only difference between the DC rotor 20 illustrated in FIG. 2b and the DC rotor shown in FIG. 2a is that instead of a central gear 32a mounted on the motor housing 12a, a central gear 32c is provided which is structurally integrated into the DC rotor 20. The central gear 32c is rotatably mounted in the rotor on guiderails (not shown for reasons of clarity) and has two retaining pins 33 on its side facing the drive motor 12, which pins 33 will engage associated recesses 33a in the motor housing 12a when the DC rotor 20 is mounted on the drive motor 12. The dimensions of the recesses 33a are adapted to the dimensions of the retaining pins 33. The retaining pins 33 engaging the recesses 33a fix the central gear 32c in the mounted state of the DC rotor 20 in such a way that it will not rotate along with the DC rotor 20 in operation. Similar to the principle explained with reference to FIG. 2a, the rotational units 30 are made to rotate when the toothing 32b meshes with the central gear 32c during operation of the centrifuge 10. For reasons of clarity, the view of FIG. 2b shows the DC rotor 20 removed from the drive motor 12.

(20) For ease of reference, FIG. 2c is a perspective view of the DC rotor 20 mounted on the drive motor 12.

(21) FIG. 3a is a lateral sectional view of an angle head rotor 40 according to the invention which is suitable for fitting on the drive motor 12, as well as of the portion of the drive motor 12 which is close to the rotor. This view shows the angle head rotor 40 after it has been taken off the drive motor 12.

(22) The angle head rotor has a central rotor hub 42 and an opening 42a through which the driveshaft 16, in a mounted state thereof, engages the angle head rotor 40. As in the case of the previously illustrated DC rotor 20, on the side of the angle head rotor 40 facing away from the drive motor 12, a quick fastener 44 is centrally provided which is engaged by the end portion 16a of the driveshaft 16 when the angle head rotor 40 is placed on the drive motor 12 and is fixed by a push-down mechanism not shown in detail for reasons of clarity.

(23) Along the periphery of the angle head rotor 40, receiving bores 46 are uniformly distributed for receiving sample containers (not shown) which bores 46 each have a longitudinal axis 46a. The receiving bores 46 are inclined relative to the rotor 40 in such a way that their longitudinal axes 46a will intersect at an acute angle on the drive axis A above the driveshaft 16. This lateral sectional view shows four receiving bores 46.

(24) As already set out with reference to FIGS. 1 and 2a, a central gear 32a is disposed on the motor housing 12a as part of the additional drive mechanism 32 required for driving the rotational units 30 in such a way that it will be penetrated by the driveshaft 16. To be able to fit the angle head rotor 40 easily on the drive motor 12 despite the presence of the central gear 32a not required for its operation, a central circumferential recess 42b associated with the central gear 32a is provided in the rotor hub 42, which recess 42b is larger than the central gear 32a so that the central gear 32a will not contact the rotor hub 42 once the angle head rotor 40 has been mounted. Consequently, also an angle head rotor 40 can be mounted in the dual centrifuge 10 intended for use with DC rotors 20.

(25) For ease of reference, the view of FIG. 3b shows the angle head rotor 40 mounted on the drive motor 12.

(26) FIG. 4a is a lateral sectional view of a swing-out rotor 50 mounted on the drive motor 12 as well as of the portion of the drive motor 12 which is close to the rotor. FIG. 4b is a perspective view of the swing-out rotor 50 and the drive motor 12.

(27) Four Y-shaped support arms 52c are formed on a rotor hub 52, between which four swing-out buckets 56 are pivotally mounted for holding four sample container receptacles (not shown) for sample containers containing samples to be centrifuged. Similar to the angle head rotor 40, the swing-out rotor 50 has a central opening 52a which is engaged by the end portion 16a of the driveshaft 16. On the side of the swing-out rotor 50 which faces away from the drive motor 12 a quick fastener 54 is centrally disposed which is engaged by the end portion 16a of the driveshaft 16 when the swing-out rotor 50 is placed onto the drive motor 12 and which is fixed by a push-down mechanism not shown in detail for reasons of clarity.

(28) As in the case of the angle head rotor 40 illustrated in FIG. 3a, a central circumferential recess 52b associated with the central gear 32a is provided in the rotor hub 52, which recess 52b is larger than the central gear 32a so as to prevent the central gear 32a from contacting the rotor hub 52 once the swing-out rotor 50 has been mounted. Consequently, a swing-out rotor 50 can also be mounted in the dual centrifuge 10 intended for use with DC rotors 20.

LIST OF REFERENCE SIGNS

(29) 10 dual centrifuge 11 centrifuge housing 11a underside 11b housing cover 12 drive motor 12a motor housing 14 motor shaft 16 driveshaft 16a end portion 20 DC rotor 22 rotor hub 22a opening 24 quick fastener 26 opening 30 rotational unit 32 additional drive mechanism 32a central gear 32b toothing 32c central gear 33 retaining pin 33a recess 34 rotational head 35 housing 36 pivot bearing 40 angle head rotor 42 rotor hub 42a opening 42b recess 44 quick fastener 46 receiving bore 46a longitudinal axis 50 swing-out rotor 52 rotor hub 52a opening 52b recess 52c support arms 54 quick fastener 56 swing-out bucket 60 safety vessel 60a sidewall 60b vessel bottom 60c opening E removal direction A drive axis R rotational axis