Rotor of a dual centrifuge

Abstract

The invention relates to a rotor (10) of a dual centrifuge wherein the rotor has a rotor head (12) and an additional rotational mechanism for at least one rotational unit (22) which is provided in the rotor head (12) and comprises a bearing unit (70) and a rotational head (24) that is connected to the bearing unit (70) which is rotatably mounted and can be driven relative to the rotor head (12) by an additional rotational mechanism, an opening (16) for the rotational unit (22) being provided in which the rotational unit is accommodated and by means of which the bearing (70) is arranged such that it is fixed relative to the rotor head (12). The invention is characterized in that the rotational unit (22) has a housing (26) in which the bearing unit (70) is accommodated and in which the rotational head (24) engages, and in that the housing (26) and the rotational head (24) form, with bearing unit (70), a structural unit, the housing (26) being mounted such that it cannot rotate relative to the rotor head (12) and such that it can be detached from the rotor head.

Claims

1. A rotor (10) of a dual centrifuge, comprising: a rotor head (12); a rotational unit (22); said rotational unit (22) comprises: a bearing unit (70); a rotational head (24) which includes a rotatable shaft (25); said rotatable shaft (25) supported by said bearing unit (70); and, a housing (26); said bearing unit (70) is mounted in said housing (26) and supports said rotatable shaft (25); said rotational head (24) includes a wall (24a); a gear (36) is affixed to said wall (24a) of said rotational head (24); a central gear (40) affixed to, and driven by, a motor; said central gear (40) engages said gear (36) driving said rotational head (24); said rotational head (24) of said rotational unit (22) is rotatable with respect to said housing (26) and is driven relative to said rotor head (12) and said housing (26) by said central gear (40) driving said gear (36) affixed to said wall (24a); a recess (16) in said rotor head (12); said bearing unit (70) resides in said housing (26); said housing (26) resides in, and is removably affixed to, said recess (16) of said rotor head (12).

2. A rotor (10) of a dual centrifuge, comprising: a rotor head (12); a rotational unit (22); a rotational head (24) includes a wall (24a); a gear (36) is affixed to said wall (24a) of said rotational head (24); a central gear (40) affixed to, and driven by, a motor; said central gear (40) engages said gear (36) driving said rotational head (24); said rotational unit (22) is provided in said rotor head (12); said rotational unit (22) forms a structural unit comprised of: a housing (26), a bearing unit (70), said rotational head (24), and, said rotational head (24) includes a shaft (25); said shaft (25) of said rotational head (24) engages said bearing unit (70); said bearing unit (70) is mounted in said housing (26); said bearing unit (70) enabling rotation of said rotational head (24) relative to said housing (26); said rotational head (24) is driven relative to said rotor head (12) by said central gear (40) driving said gear (36) affixed to said wall (24a); a recess (16) in said rotor head (12); said rotational unit (22) partially resides in said recess (16) of said rotor head (12); said housing (26) of said rotational unit (22) is fixed to said rotor head (12); and, said housing (26) cannot rotate relative to said rotor head (12) and is detachable from said rotor head.

3. The rotor (10) according to claim 2, further comprising: said recess (16) extends through a portion of said rotor head (12); said rotational unit (22) is mounted therein and extends through said recess (16); and, a lower portion of said housing (26) of said rotational unit (22) protrudes from said recess (16).

4. The rotor (10) according to claim 3, further comprising: said rotor head includes a rotationally symmetrical shape defining an envelope (12A).

5. The rotor (10) according to claim 4, further comprising: said housing (26) has a height and at least 30% of said height of said housing (26) protrudes beyond said envelope (12A).

6. The rotor (10) according to claim 3, further comprising: said lower region of said housing (26) has cooling ribs (42).

7. The rotor (10) according to claim 3, further comprising: said rotational unit (22) is securely connected to said rotor head (12) by a releasable quick fastener or a screw connection.

8. The rotor (10) according to claim 3, further comprising: said housing (26) has sides, one of said sides includes a plurality of cooling ribs, and on another side of said housing (26) remote from said side which includes said plurality of cooling ribs (42), a flange (84) is provided which bears against said rotor head (12).

9. The rotor (10) according to claim 3, further comprising: said recess (16) and said housing (26) are adapted to each other.

10. The rotor (10) according to claim 9, further comprising: said housing (26) includes a cross-sectional shape and said recess (16) includes a cross-sectional shape; said cross-sectional shape of said housing (26) and said cross-sectional shape of said recess (16) prevent rotation, said housing (26) and said recess (16) being in a polygonal shape or a cylindrical shape with projections and associated grooves.

11. The rotor (10) according to claim 3, further comprising: a housing cover (80) with a central bore for said shaft (25) of said rotational head (24); and, said housing (26) and said housing cover (80) define a bearing space (64) for said bearing unit (70).

12. The rotor (10) according to claim 11, further comprising: said bearing space (64) is sealed in a lubricant-tight manner.

13. The rotor (10) according to claim 12, further comprising: said bearing space (64) is filled with lubricant; and, said lubricant is roller-bearing grease.

14. The rotor (10) according to claim 12, further comprising: said bearing space (64) is filled with lubricant up to 50% of said height of said bearing space (64).

15. The rotor (10) according to claim 3, further comprising: said rotational unit (22) has a wall (26a); and, said wall (26a) of said rotational unit (22) is in contact with said rotor head (12) for heat dissipation.

16. A rotational unit (22) for a rotor, comprising: a housing (26), a bearing unit (70) and a rotational head (24) form a structural unit; a rotor head (12) includes a recess (16) therein; said housing (26) has sides, one of said sides includes a plurality of cooling ribs, and on another side of said housing (26) remote from said side which includes said plurality of cooling ribs (42), a flange (84) is provided which bears against said rotor head (12); said housing of said structural unit and said structural unit is removably mounted to said rotor head (12); a gear (36) is affixed to a wall (24a) of said rotational head (24); a central gear (40) is affixed to, and driven by, a motor; said central gear (40) engages said gear (36) driving said rotational head (24); said rotational head (24) of said rotational unit (22) is rotatable with respect to said housing (26).

Description

(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 which follows below. In the drawings:

(2) FIG. 1a is a perspective view of a rotor 10 according to the invention with two rotational units 22;

(3) FIG. 1b is a sectional view of the rotor 10 of FIG. 1a;

(4) FIG. 2 is a perspective view of an inventive embodiment of a rotational head 24 without the gearing 36;

(5) FIG. 3 is a perspective view of an adapter 50 according to the invention;

(6) FIG. 4 is an exploded view of a rotational unit 22 of the invention;

(7) FIG. 5a is a view of the rotational unit 22 of in FIG. 4; and

(8) FIG. 5b is a view of a lateral section of the rotational unit 22 shown in FIG. 4 and FIG. 5a taken along the cutting line and in the cutting direction C-C depicted in FIG. 5a.

(9) FIG. 1a is a perspective view of a rotor 10 according to the invention with two rotational units 22 for use in a dual centrifuge not shown in the figures. FIG. 1b is a sectional view of the rotor 10 illustrated in FIG. 1a.

(10) The rotor 10 has a rotor head 12 of a rotationally symmetrical basic shape, which defines an envelope. The rotor head 12 is provided with a bottom 15 and a circumferential wall 14 which surrounds the bottom 15 and extends upwardly. A drive axis A runs perpendicularly through the center 13 of the rotor head 12. A drive shaft not shown in the figures extends with its free end through a recess 18 which is provided in the bottom 15 and concentric with the drive axis A. Above the recess 18, a receiving tube 20 is disposed which is integrally formed with the bottom 15 and which serves to center and vertically secure the rotor head 12 on the drive shaft.

(11) The wall 14 has a vertical portion 14a and an oblique portion 14b which inclines downward toward the drive shaft. Two recesses 16 are provided which are located opposite each other relative to the drive axis A and which partially extend through the vertical portion 14a of the wall 14 and the oblique portion 14b of the wall 14. The rotational units 22 are accommodated in the respective recesses 16.

(12) The rotational units 22 each have an axis of rotation R1, R2 and are aligned by the recesses 16 in such a way that the rotational axes R1 and R2 intersect the drive axis A at an acute angle above the rotor 10. Furthermore, the free ends of the rotational units 22 facing away from the drive axis A, i.e. the housings 26 described below, protrude from the envelope in the area of the oblique portion 14b of the wall 14.

(13) Each rotational unit 22 has a largely rotationally symmetrical outer contour, and comprises a rotatably mounted rotational head 24 (see FIG. 2) for supporting an adapter 50 for material to be centrifuged (see FIG. 3), and a housing 26 (see FIG. 4) in which a bearing 70 for the rotational head 24 is provided, which is in turn engaged by the rotational head 24 with a bearing shaft 25 that is provided on its side facing the housing 26. Part of the bearing shaft 25 is visible in FIG. 2 and in FIG. 5b.

(14) The rotational head 24 has an outer wall 24a which is concentric to the axis of rotation R1, R2. The housing 26 is provided with a wall 26a which is concentric to the axis of rotation R1, R2. The diameter of the rotational head 24 is larger than that of the housing 26 so that a shoulder 28 is formed between the outer wall 24a and the wall 26a with which the rotational unit 22 partially engages its associated recess 16, see FIG. 1a.

(15) The dimensions of the housing 26 are adapted to the respective associated portions of the recesses 16. To ensure the non-rotatable connection of the housing 26 and the rotor head 12, a groove is formed in the housing 26 parallel to the axis of rotation R1, R2 and a projection is provided on the rotor head 12, which projection is associated with the groove. For the sake of clarity, the groove and the projection are not shown in the figures. Moreover, the arrangement of the groove and the projection may also be reversed. Furthermore, it is also conceivable to choose a polygonal design instead of the cylindrical design of the housing 26 so as to ensure that the housing is mounted in the rotor head in a non-rotatable manner.

(16) According to FIG. 1a, the rotational head 24 is furthermore closed on the side remote from the housing 26 by a closure cap 30 which is concentrically arranged relative to the axis of rotation R1, R2. A closure knob 32 is likewise concentrically arranged on the closure cap 30, which knob 32 serves as a handle to unlock the closure cap 30 by a rotary movement and remove it, and/or to put the closure cap 30 on and lock it in place by a rotary movement against the unlocking direction.

(17) A circumferential projection 34 is provided on the upper wall 24a adjacent to the shoulder 28, see FIG. 2 for example, which projection 34 securely mounts a gearing 36, which is non-rotatably connected to the wall 24a, in a concentric alignment relative to the axis of rotation R1, R2. For transmitting the rotary movement of the rotational heads 24 about the axes of rotation R1, R2 of the rotational units 22, a gear is provided below the rotor head 12 for each rotational head 24, which gear is not shown in the figures for the sake of clarity. This gear 24 is in engagement with the gearing 36 on the one hand and with a central gear 40 which is non-rotatably connected to a motor housing not shown in the figures opposite the rotatable rotor head 12, for example by a screw connection. Such a transmission of rotary movements is well known and described in the prior art, so that no further explanations are required here.

(18) The ratio of the main rotation (rotation of the rotor 10) to the reverse rotation (rotation of the rotational head 24) is given by the transmission ratio between the gear wheel (not shown) and the central gear 40. With the rotor head 12 removed, the gear (not shown) and the central gear 40 can be easily replaced. Therefore the speed ratio can be changed easily, by adapting the diameters of the gear (not shown) and the central gear 40.

(19) The side of the housing 26 which is remote from the rotational head 24 has cooling ribs 42. The cooling ribs 42 are aligned perpendicular to the direction of rotation of the rotor head 12.

(20) FIG. 2 is a perspective view of an inventive embodiment of a rotational head 24 without the gearing 36. Evenly spaced recesses 34a are arranged along the entire periphery of the projection 34 through which screws 36a extend which are provided on the underside of the gearing 36, as seen in FIG. 1a, and which engage in associated threaded bores in the gearing 36. The screws 36a extending through the recesses 34a securely mount the gearing 36 on the wall 24a and in the rotational head 24 and in particular ensure that the gearing is non-rotatably mounted relative to the rotational head 24.

(21) Within the wall 24b, walls 44 are mounted on a base plate 24b, which walls 44 are adapted to securely mount an adapter 50 shown in FIG. 3 for material to be centrifuged. The walls 44 define an inner profile which is matched to the outer profile of the adapter 50 of FIG. 3, which adapter 50 has a cross-shaped base area of two superposed rectangles which are concentrically rotated orthogonally to each other. The walls 44 are partially connected to each other for improved stability. Four walls 44, of which two each are disposed opposite each other as a pair, each have an outer profile 44a formed thereon which is rounded in such a manner that it is concentric with the wall 24a. The wall 24a has four equally spaced bores 24c adjacent its upper edge, which bores 24c are adapted to lock the closure cap 30 that has corresponding projections.

(22) FIG. 3 is a perspective view of the aforementioned adapter 50 for material to be centrifuged. On the periphery of the aforementioned cross-shaped base area, the adapter 50 has vertically disposed integral outer walls 52. Within the outer walls 52, five rectangular recesses 56 are provided which are delimited from each other by partition walls 54, with the vertical extension of the recesses 56 corresponding to the vertical extension of the wall 24a of the rotational head 24. The recesses 56 are used to receive the sample container receptacles not shown in the figures and are adapted to the shape of the sample container receptacles.

(23) Adjacent to the free upper edges of the outer walls 52 of the adapter 50, a bearing surface 58 is disposed perpendicularly on the outer walls 52, which surface 58, in the inserted state of the adapter 50, will rest on the free upper edges of the walls 44. The bearing surface 58 has an outer contour 60 which is substantially concentric with the wall 24a of the rotational head 24 and which has four bulges 62 which are equally spaced from one another over the periphery. The bulges 62 facilitate handling of the adapter 50 during insertion into and removal from the rotational head 24.

(24) FIG. 4 is an exploded view of the rotational unit 22 comprising the rotational head 24 and the housing 26 with a bearing unit 70 integrated in the housing 26, with a drive shaft not shown for reasons of clarity extending concentrically through said bearing unit 70.

(25) Starting from the housing 26, disposed along the axis of rotation R1, R2 are a clamping nut 72 for biasing the bearing unit 70, two single-row angular contact ball bearings 74a and 74b, an outer washer 76 located between the angular ball bearings 74a and 74b, as well as an inner washer 78 and a cover disk 80. All of the above elements of the bearing unit 70 have concentric bores, through which the bearing shaft 25 of the rotational head 24 extends in a play-free manner.

(26) On the cover disk 80, eight recesses 82 are provided at equal intervals and adjacent to the outer periphery. On the side associated with the rotational head 24, the housing 26 has a flange 84 which in turn has eight recesses 86 arranged at regular intervals that are associated with the recesses 82.

(27) FIG. 5a is a bottom view of the rotational unit 22. A cylinder screw 88 each engages the recesses 82 of the cover disk 80 and extends through the associated recesses 86 of the flange 84. Five recesses 82a each and five recesses 86a associated with the recesses 82a are provided. The cylinder screws 88 provide a screw connection of the housing 26 and the cover disk 80 in such a way that they, together with the bearing shaft 25 of FIG. 2, delimit a bearing space (64) which is encapsulated toward the outside in a lubricant-tight manner (see FIG. 5b).

(28) It is well known how to fit angular contact ball bearings in pairs and how to bias them, so that further explanations are unnecessary here.

(29) FIG. 5b is a view of a cross-section of the mounted rotational unit 22 shown in FIGS. 4 and 5a taken along a line C-C depicted in FIG. 5a. A lubricant refill valve having a valve line 92 is provided on the wall 26a between the bottom plate 24b and the angular contact ball bearings 74b. If necessary, this lubricant refill valve can be used to refill lubricant into the bearing space 64 which is encapsulated from the outside in a lubricant-tight manner. A lubricant level indicator 90 arranged on the wall 26a outside the housing 26 is used for inspecting the lubricant level.

LIST OF REFERENCE SIGNS

(30) 10 rotor 12 rotor head 13 center 14 wall 14a vertical portion 14b inclined portion 15 bottom 16 recesses 18 recess 20 receiving tube 22 rotational unit 24 rotational head 24a outer wall 24b base plate 24c bores 25 bearing shaft 26 housing 26a wall 28 shoulder 30 closure cap 32 closure knob 34 projection 34a recess 36 gearing 36a screws 40 central gear 42 cooling ribs 44 walls 44a outer profile 50 adapter 52 outer walls 54 partition walls 56 recesses 58 bearing surface 60 outer contour 62 bulges 64 bearing space 70 bearing unit 72 clamping nut 74a, b angular ball bearings 76 outer washer 78 inner washer 80 cover disk 82 recesses 82a recesses 84 flange 86 recesses 86a recesses 88 cylinder screws 90 lubricant level indicator 92 lubricant refill valve A drive axis R1, R2 axes of rotation