System and method for balancing a centrifugal rotor

Abstract

To provide an improved system and method for performing balancing of a centrifuge rotor.SOLUTION: A rotor hub assembly for a centrifuge rotor includes a rotor hub including a head portion, an elongated shaft portion extending axially away from the head portion, and a central bore extending through the head portion and the shaft portion. The head portion includes a plurality of balancing bores each configured to selectively receive at least one balancing weight for performing balancing of the centrifuge rotor. A method for performing balancing of a centrifuge rotor is also provided.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention generally relates to centrifuge rotors, and more particularly to balancing rotors for use with centrifuges.

Background Art

[0002] Centrifuge rotors are typically used in laboratory centrifuges to hold samples during centrifugation. Centrifuge rotors can vary significantly in construction and size, but one common rotor structure is the fixed-angle rotor, which has a solid rotor body with a plurality of cell-hole cavities radially dispersed and arranged symmetrically with respect to the axis of rotation. Samples are positioned within the cavities, allowing multiple samples to be centrifuged.

[0003] Centrifuge rotors are typically used in high-speed applications where the speed of the centrifuge can exceed several hundred or even thousands of revolutions per minute, and thus must be carefully balanced. In this regard, variations in the mass of the rotor load can create undesirable force imbalances at high rotor speeds. This force imbalance can distort the spindle driving the rotor, causing damage to the centrifuge, as well as inefficiencies, wear, and noise. Conventional balancing techniques use combinations of samples and balance tubes that are all of the same weight, or various other balancing patterns that do not use balance tubes.

[0004] To detect rotor imbalance and identify specific locations in the rotor body where additional weights are needed for proper balancing, diagnostic devices or balancing machines, such as those commercially available from American Hofmann Corporation of Lynchburg, Virginia, or Schenck Corporation of Deer Park, New York, may be used. Holes are then manually drilled at the identified locations in the rotor body, which may be constructed of carbon fiber, and weights are pressed into these holes according to the information provided by the diagnostic device. The weights may be, for example, cylindrical metal bodies having a specific mass to counteract the imbalance detected by the diagnostic device.

[0005] Rotors often require rebalancing multiple times throughout their service life. For example, as a rotor wears down over time, its mass distribution can change, necessitating rebalancing. When this occurs, typically, previously installed weights must be removed from previously drilled holes, and new holes must be drilled in the rotor body, into which the same or new weights can be pressed. Thus, the previously drilled holes become unused. Often, it is desirable to fill the previously drilled holes for structural and / or aesthetic purposes, which requires repair of the rotor body. The cycle of drilling new holes in the rotor body and repairing it to fill the previously drilled holes is repeated each time the rotor is rebalanced.

[0006] Therefore, it would be desirable to provide improved systems and methods for balancing centrifugal rotors to address these and other problems associated with conventional rotors. [Overview of the project]

[0007] This invention overcomes the aforementioned and other shortcomings and drawbacks of systems and methods for balancing centrifugal rotors that are known to date. While this invention is discussed in relation to specific embodiments, it will be understood that this invention is not limited to these embodiments. On the contrary, this invention includes all substitutes, modifications, and equivalents that may fall within the spirit and scope of this invention.

[0008] According to one embodiment, a rotor hub assembly for a centrifuge rotor is provided, the rotor hub assembly having a rotor hub, the rotor hub including a head, an elongated shaft portion extending axially away from the head, and a central hole extending through the head and the shaft portion. The head includes a plurality of balance holes, each configured to selectively receive at least one balance weight.

[0009] To balance the rotor, a diagnostic device may be used to detect imbalances in the rotor and identify at least one target position on the rotor hub and at least one corresponding target weight amount, and proper balancing of the rotor is assisted by adding the target weight to the target position on the hub. Next, a suitable balance hole corresponding to the target position and a balance weight having a weight relatively close to the target weight amount may be selected.

[0010] In one embodiment, at least one balance weight includes at least one set screw having at least one threaded outer surface, and the plurality of balance holes are threaded.

[0011] The head of the rotor hub may include a plurality of fastening holes, each configured to selectively receive fasteners for attaching at least one ring to the rotor hub. In one embodiment, at least one ring is attached to the rotor hub and covers at least one balance weight inserted into at least one balance hole. The ring may include at least one of a magnetic ring or an annular shield. If the ring is magnetic, the magnetic ring may include a plurality of blind holes on its upper surface to selectively receive a plurality of corresponding magnets. A selected arrangement of magnets on the magnetic ring produces a magnetic field that can be identified via the Hall effect, which may be detectable by a centrifuge or an associated sensor / reader, so that the centrifuge can identify the rotor hub and / or rotor installed within the centrifuge. When the ring is a shield, the shield may be constructed of a highly magnetic material capable of preventing the magnetic field produced by the magnets from being directed upward toward the hub, and rather concentrating the magnetic field downward toward the sensor / reader of the centrifuge.

[0012] According to another embodiment, a centrifuge rotor is provided, which includes a rotor body having a plurality of tubular cavities, each cavity configured to receive a sample container inside. The centrifuge rotor further includes a rotor hub assembly as described above, the rotor hub configured to transmit torque from the centrifuge spindle to the rotor body.

[0013] A method for operating a centrifuge rotor is also provided, comprising a rotor body having a plurality of tubular cavities and a rotor hub having a plurality of balance holes, each of which is configured to selectively receive at least one of a plurality of balance weights.

[0014] A method according to one embodiment includes the steps of detecting an unbalance in a centrifuge rotor and selectively engaging at least one of a plurality of balance weights with at least one of a plurality of balance holes, depending on the detected unbalance.

[0015] A balancing method may also include the step of identifying at least one target position on the rotor hub and at least one corresponding target weight amount to be added to at least one target position below the hub in order to balance the rotor.

[0016] An exemplary method may also include the step of selecting at least one of a plurality of balance holes and at least one of a plurality of balance weights, depending on at least one identified target location and at least one corresponding target weight amount, respectively.

[0017] Various additional features and advantages of this invention will become more apparent to those skilled in the art upon careful reading of the following detailed description of exemplary embodiments together with the accompanying drawings. [Brief explanation of the drawing]

[0018] The accompanying drawings, incorporated into and forming part of this specification, illustrate embodiments of the present invention and, together with the general description of the invention presented above and the detailed description presented below, serve to illustrate the present invention.

[0019] [Figure 1] This is a perspective view of a hub assembly for a centrifugal rotor according to one embodiment of the present invention. [Figure 2] Figure 1 is an exploded perspective view of the hub assembly. [Figure 3A] This is an exploded cross-sectional view of the hub assembly in Figure 1, obtained along the cutting line 3A-3A. [Figure 3B] This is an exploded cross-sectional view of the hub assembly in Figure 1, obtained along the cutting line 3B-3B. [Figure 4] Figure 1 is a cross-sectional view of the centrifuge rotor, including the hub assembly. [Figure 5] This is a cross-sectional view similar to that of Figure 4 of a centrifugal rotor and hub assembly according to an alternative embodiment of the present invention. [Modes for carrying out the invention]

[0020] Referring to Figures 1 to 3B, an exemplary hub assembly 10 for a centrifugal rotor 12 (Figure 4) according to one embodiment of the present invention is illustrated. The hub assembly 10 includes a rotor hub 14 and at least one balance weight 16 that can be embedded in a removable manner within the rotor hub 14. As will be described in more detail below, the balance weight 16 can be selectively positioned at various predetermined positions in the rotor hub 14 for balancing the rotor 12.

[0021] The illustrated rotor hub 14 may be constructed of a metallic material such as titanium, and includes a head 20 and an elongated shaft portion 22 extending axially from the head 20. The shaft portion 22 includes a threaded outer end face 24 distal to the head 20 and a threaded outer intermediate face 26 proximal to the head 20. As best shown in Figures 3A and 3B, a central multi-stage bore 30 extends through the head 20 and the shaft portion 22 of the rotor hub 14, and the central multi-stage bore 30 includes a threaded inner surface 32 located within the shaft portion 22 distal to the head 20.

[0022] An annular depression 34 is provided on the bottom side surface of the rotor hub 14 distal from the shaft portion 22, and a plurality of threaded fastening holes 36 spaced circumferentially apart are opened in the depression 34. Each of the fastening holes 36 is configured to receive a corresponding fastener 38 in a screwed manner to attach a ring such as a magnet ring 40 and / or an annular shield 42 to the bottom side surface of the rotor hub 14. In this regard, the exemplary magnet ring 40 includes a plurality of through holes 44 each configured to receive a corresponding one of the fasteners 38. The magnet ring 40 may also include a plurality of detent holes 46 on its upper side surface for selectively receiving a plurality of corresponding magnets 48. The selected arrangement of the magnets 48 on the magnet ring 40 provides a magnetic field that can be identified via the Hall effect and detected by a centrifuge (or a sensor / reader associated therewith), so that the centrifuge (or a controller associated therewith) can identify the hub 14 and / or the rotor 12, as would be understood by one of ordinary skill in the art. For example, the centrifuge (or its controller) can compare the detected magnetic field with various magnetic field values stored in a database to identify a particular rotor 12 or the type of rotor 12 within the centrifuge.

[0023] The exemplary annular shield 42 includes a plurality of through holes 50 each configured to receive a corresponding one of the fasteners 38, so that the annular shield 42 can be sandwiched between the magnet ring 40 and the head 20 of the rotor hub 14 within the depression 34 when the fasteners are received in the corresponding fastening holes 36 in a screwed manner. The shield 42 can be constructed of a highly magnetic material that prevents the magnetic field provided by the magnets 48 from being directed upwardly toward the hub 14 and instead concentrates the magnetic field downwardly toward the centrifuge's sensor / reader. In one embodiment, the shield 42 can be constructed of mu-metal (e.g., ASTM A753 Alloy 4).

[0024] An exemplary head 20 of the rotor hub 14 further includes a plurality of threaded balance holes 52 that are circumferentially spaced apart and open to the recess 34. In the illustrated embodiment, each of the balance holes 52 extends generally parallel to the central hole 30 of the rotor hub 14. Each of the balance holes 52 is configured to selectively receive and thread one of the balance weights 16 for balancing the rotor 12. More specifically, the balance holes 52 may have a uniform configuration such that each of the balance holes 52 has, for example, the same depth, cross-sectional dimensions, and / or thread pitch. In this manner, each of the balance holes 52 may be capable of receiving the same balance weight 16 in a threaded manner. In the illustrated embodiment, the uniform configuration of the balance holes 52 is different from the configuration of the fastening holes 36 such that the balance holes 52 may receive only the balance weights 16 while the fastening holes 36 may receive only the fasteners 38.

[0025] In the illustrated embodiment, as best shown in FIG. 2, eight balance holes 52 are provided and are arranged in four pairs and circumferentially spaced from each other about the central hole 30. Thus, the balance holes 52 define eight predetermined locations on the rotor hub 14 for receiving the balance weights 16. However, any suitable number of balance holes 52 may be used at any suitable spacing. In this regard, the cross-sectional dimensions of the head 20 may affect the surface area available for the balance holes 52 and may be increased, for example, to provide additional surface area for accommodating a greater number of balance holes 52. As will be appreciated, the number of balance holes 52 may correlate to the number of options for positioning the balance weights 16 and may also correlate to the degree of control of the center of gravity of the rotor hub 14 that affects the stability of the rotor 12.

[0026] The illustrated balance weight 16 includes a set screw 60, which has a threaded outer surface 62 and extends between a first end 64 and a second end 66 that define the length of the balance weight 16. The first end 64 is provided with a hexagonal socket 68 for receiving a tool such as a wrench, which assists in advancing the balance weight 16 into or out of one of the balance holes 52. The threaded outer surface 62 of the balance weight 16 allows for easy insertion into or removal from one of the balance holes 52 without causing any deformation to the rotor hub 14 or any other component of the rotor 12. The exemplified balance weights 16 and balance holes 52 are threaded, so that the balance weight 16 can be reliably and removably engaged with one or more of the balance holes 52, while the balance weight 16 can be reliably and / or removably engaged with the hub 14 by any other suitable means. In one embodiment, a plurality of balance weights 16 having various different lengths and / or masses may be supplied, so that balance weights 16 with different balancing characteristics can be selectively positioned within a particular balance hole 52 to achieve customized balancing.

[0027] In the embodiment shown, the balance weight 16 may be covered by a magnetic ring 40 and / or annular shield 42, or concealed within a corresponding balance hole 52 by the magnetic ring 40 and / or annular shield 42, thereby preventing the balance weight 16 from being visible from outside the hub assembly 10 or easily accessible.

[0028] Referring next to Figure 4, the rotor hub assembly 10 may be used in a centrifuge rotor 12. The rotor 12 includes a rotor body 70 that is symmetrical with respect to the axis of rotation defined by the rotor hub 14, and a sample contained in a sample container (not shown) positioned within the rotor body 70 can be centrifuged around the axis of rotation.

[0029] The illustrated rotor body 70 includes a substantially cylindrical hole 72 for receiving at least the shaft portion 22 of the hub 14, the hole 72 being configured to be coaxial with the hub 14, thereby allowing the hole 72 to also define an axis of rotation. As shown, a number of recesses 74 are provided around the hole 72, the purpose of which is explained below. The rotor body 70 also includes upper and lower cavities 76 and 78 adjacent to both ends of the hole 72.

[0030] Multiple tubular cell cavity 80 extend from the upper cavity 76 into the rotor body 70. Each cavity 80 is suitably sized and shaped to accommodate at least one of the sample containers for centrifugal rotation of the sample containers around the axis of rotation. It will be recognized that any suitable number of cell cavity 80 may be used. The term “tubular” as used herein refers to any suitable cross-sectional shape, which includes, but is not limited to, rounded corners (e.g., elliptical, circular, or conical), quadrilateral, regular polygon, or irregular polygon, or any other suitable shape. Thus, the term is not intended to be limited to the substantially circular cross-sectional profile of the exemplary cavity 80 illustrated in the figure. In one embodiment, the rotor body 70 is constructed of carbon fiber material. For example, the rotor body 70 may be compression-molded from layers of resin-coated carbon fiber laminate material.

[0031] In the shown embodiment, the rotor body 70 and the rotor insert 82 are co-molded within the hole 72. The insert 82 securely mounts the rotor body 70 on the hub 14 by including at least a threaded hole 84 to receive and engage with the threaded outer intermediate surface 26 of the shaft portion 22 of the hub 14 in a manner that screws into the outer intermediate surface 26. The insert 82 also includes a plurality of webs 86, each of which is received in one of the corresponding recesses 74 of the rotor body 70. When the rotor 12 is rotated during use, the hub 14 applies torque to the insert 82, and the insert 82 applies torque to the rotor body 70, for example, through engagements between the webs 86 and the recesses 74.

[0032] With the rotor body 70 mounted on the rotor hub 14, a hub retainer 90 is removably fastened to the hub 14 to further facilitate holding the rotor body 70, the hub 14, and the insert 82 in place relative to each other. In this regard, the hub retainer 90 includes at least a threaded hole 92 to receive the threaded outer end face 24 of the shaft portion 22 of the hub 14 and to engage with the outer end face 24 in a manner that it screws into the outer end face 24.

[0033] The rotor 12 also includes a lid 100 that is removably coupled to the rotor hub 14 above the rotor body 70 to assist in holding the sample container within it while the rotor body 70 is rotating. An illustrated lid 100 is substantially disc-shaped and includes a central hole 102 and a peripheral groove 104, the purposes of which are described below, for receiving an O-ring 106 to provide a fluid seal between the lid 100 and the rotor body 70 when the lid 100 is removably coupled to the rotor body 70. In one embodiment, the lid 100 is constructed of carbon fiber material. For example, the lid 100 may be compression-molded from layers of resin-coated carbon fiber laminate material.

[0034] As shown, the lid 100 can be attached to the rotor body 70 in a removable manner via a lid screw 110. The illustrated lid screw includes an upper flange 112, a threaded lower outer surface 114, and a multi-stage hole 116. As shown, the threaded lower outer surface 114 is received by and engages with the threaded inner surface 32 of the hub 14 in a screw-in manner, thereby causing the upper flange 112 to press the spacer 118 against the lid 100. When the lid 100 is attached to the rotor body 70 in a removable manner via the engagement of the lid screw 110 with the hub 14 and the engagement of the spacer 118 with the lid 100, it prevents access to the sample container held in the cavity 80, such as during high-speed rotation. A tie-down screw or pin 120 may be inserted through the hole 116 of the lid screw 110 and attached in a screw-in manner to the knob 122. The tie-down pin 120 may be configured to engage with a cooperating hole in a centrifuge spindle (not shown), which then assists in mounting the rotor 12 to the centrifuge spindle. As shown, the tie-down pin 120 may be biased away from the centrifuge spindle by a helical spring 124. The threshold force of the helical spring 124 may be overcome, prompting the tie-down pin 120 to engage with the hole in the centrifuge spindle, which can then be actuated to drive the rotor 12 to high-speed centrifugal rotation. As those skilled in the art will recognize, one or more of the rotor mounting components described above may be made of any suitable metallic or non-metallic material.

[0035] To balance the rotor 12, a diagnostic device may be used to detect an imbalance in the rotor 12 and to identify at least one target position on the hub 14 and at least one corresponding target weight amount, and proper balancing of the rotor 12 is assisted by adding the target weight to the target position on the hub 14. Depending on the specific diagnostic device used, the user may input a radius value (e.g., distance from the axis of rotation) indicating that the target position is desired to be on the hub 14 rather than on the rotor body 70. A suitable balance hole 52 corresponding to the target position and a balance weight 16 having a weight relatively close to the target weight amount may then be selected.

[0036] To counteract the imbalance detected by the diagnostic device, at least one selected balance weight 16 may then be engaged in a manner that screws into at least one balance hole 52, according to the information provided by the diagnostic device. For example, as shown, a single balance weight 16 may be engaged in a manner that screws into one of the balance holes 52, while the remaining balance holes 52 may be left open. Alternatively, any number of balance weights 16 may be mounted in any number of balance holes 52, as this may be appropriate for achieving the desired balancing of the rotor 12. In any case, the balance weights 16 may be concealed within each of the balance holes 52 as described above, and the balanced rotor 12 can be safely rotated at high speed for centrifugal separation.

[0037] Subsequently, rebalancing of the rotor 12 can be performed by detecting a new imbalance in the rotor 12, as well as by, for example, disengaging one or more balance weights 16 by simply screwing them into their respective balance holes 52, repositioning the removed balance weights 16 into different balance holes 52, engaging one or more different balance weights 16 into one or more different balance holes 52 by screwing them into one or more different balance holes 52, and / or replacing the removed balance weights 16 with one or more balance weights 16 having different lengths and / or masses. Thus, the balance weights 16 and balance holes 52 eliminate the need to repeatedly drill holes in the rotor body 70, or the need to close such holes when they are no longer used during rebalancing.

[0038] While the balance weights 16 and corresponding balance holes 52 have been described with respect to the exemplified hub assembly 10 and rotor 12, the balance weights 16 and balance holes 52 may be incorporated into any suitable hub assembly and / or rotor. For example, the balance weights 16 and balance holes 52 may be incorporated into a hub assembly that does not feature a magnetic ring 40 (including magnets 48) and / or annular shield 42. In such cases, the balance weights 16 may be concealed using a dedicated cover, or the balance weights 16 may be exposed. In addition, or alternatively, the balance weights 16 and balance holes 52 may be incorporated into other carbon fiber rotors of various designs and / or rotors constructed from different materials.

[0039] For example, and not limited to, other exemplary rotors suitable for balancing by the rotor balancing method described herein are the rotors of models F10-4x1000 LEX, F21-8x50y, F12-6x500 LEX, F20-12x50 LEX, F14-14x50cy, F14-6x250y, and F17-6x250 LEX, commercially available from the common applicant, Fiberlite Centrifuge, LLC of Santa Clara, CA.

[0040] Figure 5 illustrates a centrifuge rotor 12a and hub assembly 10a according to an alternative embodiment of the present invention, such as the centrifuge rotor of the common applicant's Model F10-4x1000.

[0041] The centrifuge rotor 12a in Figure 5 includes four circumferentially spaced cell cavity 80a, each configured to detachably receive a large-capacity sample container, such as a sample container capable of holding at least 750 ml and up to 1000 ml of sample. Exemplary large-capacity sample containers suitable for use with the rotor 12a in Figure 5 are described in full in U.S. Patents 8,215,508 and 9,987,634, each owned by the common applicant and incorporated herein by reference.

[0042] Similar to the embodiment of the centrifuge rotor 12 and hub assembly 10 in Figure 4, the hub assembly 10a for the centrifuge rotor 12a in Figure 5 includes a rotor hub 14a and at least one balance weight 16a, similar to the balance weight 16 in Figure 4, which can be embedded in the rotor hub 14a in a removable manner.

[0043] The illustrated rotor hub 14a, like the rotor hub 14 in Figure 4, may be constructed of a metallic material such as titanium, and includes a head 20a and an elongated shaft portion 22a extending axially from the head 20a. The shaft portion 22a includes a threaded outer end face 24a distal to the head 20a and a threaded outer intermediate face 26a proximal to the head 20a. A central multi-stage hole 30a extends through the head 20a and the shaft portion 22a of the rotor hub 14a, and the central multi-stage hole 30a includes a threaded inner surface 32a located within the shaft portion 22a distal to the head 20a.

[0044] An annular recess 34a is provided on the bottom surface of the rotor hub 14a distal to the shaft portion 22a, and a plurality of threaded fastening holes (not shown) are opened in the recess 34a, spaced apart in the circumferential direction, similar to the fastening hole 36 in Figure 3A. Each of the fastening holes (not shown) is configured to receive a corresponding fastener (not shown) in a manner similar to the fastener 38 in Figures 3A and 3B, thereby attaching the magnetic ring 40a and / or annular shield 42a to the bottom surface of the rotor hub 14a. The illustrated magnetic ring 40a includes a plurality of through holes (not shown), similar to the through hole 44 in Figure 3A, each configured to receive one corresponding fastener (not shown). The magnetic ring 40a may also include a plurality of blind holes (not shown) on its upper surface, similar to the blind hole 46 in Figure 3B, for selectively receiving a plurality of corresponding magnets (not shown), similar to the magnets 48f in Figures 3A and 3B. A selected arrangement of magnets on the magnetic ring 40a produces a magnetic field that can be identified via the Hall effect, which may be detectable by a centrifuge (or associated sensor / reader), so that the centrifuge (or associated controller) can identify the hub 14a and / or rotor 12a, as will be understood by those skilled in the art. For example, the centrifuge (or its controller) can identify a particular rotor 12a or type of rotor 12a within the centrifuge by comparing the detected magnetic field with various magnetic field values ​​stored in a database.

[0045] Similar to the annular shield 42 in Figures 3A, 3B, and 4, the annular shield 42a includes a plurality of through holes (not shown), similar to the through hole 50 in Figure 3A, each configured to receive a corresponding fastener (not shown), so that the annular shield 42a can be sandwiched between the magnet ring 40a and the head 20a of the rotor hub 14a within the recess 34a when a fastener (not shown) is received in such a manner that it screws into the corresponding fastening hole (not shown). As described above in relation to the shield 42 in Figures 3A, 3B, and 4, the shield 42a may be constructed of a highly magnetic material capable of preventing the magnetic field provided by the magnet (not shown) from being directed upward toward the hub 14a, and rather concentrating the magnetic field downward toward the centrifuge sensor / reader. In one embodiment, the shield 42a may be constructed of mu-metal (e.g., ASTM A753 Alloy 4).

[0046] The head 20a of the rotor hub 14a further includes a plurality of circumferentially spaced threaded balance holes 52a that open into the recess 34a. In the shown embodiment, each of the balance holes 52a extends substantially parallel to the central hole 30a of the rotor hub 14a. Each of the balance holes 52a is configured to selectively and screw into one of the balance weights 16a in order to balance the rotor 12a in a manner similar to the balancing method described in detail above in relation to the centrifuge rotor 12 of Figure 4.

[0047] Similar to the centrifuge rotor 12 in Figure 4, the balance weight 16a may be covered by a magnetic ring 40a and / or annular shield 42a, or the balance weight 16a may be concealed within the corresponding balance hole 52a by the magnetic ring 40a and / or annular shield 42a, thereby preventing the balance weight 16a from being visible from or easily accessible from outside the hub assembly 10a.

[0048] As shown in Figure 5, the rotor 12a includes a rotor body 70a that is symmetrical with respect to the axis of rotation defined by the rotor hub 14a, and a sample contained in a sample container (not shown) positioned within the rotor body 70a can be centrifuged around the axis of rotation.

[0049] The rotor body 70a in Figure 5 includes a substantially cylindrical hole 72a for receiving at least the shaft portion 22a of the hub 14a, and the hole 72a is configured to be coaxial with the hub 14a, thereby allowing the hole 72a to also define an axis of rotation.

[0050] A tubular cell cavity 80a extends from the upper cavity 76a into the rotor body 70a. Each of the cavities 80a is suitably sized and shaped to accommodate at least one of the sample containers for centrifugal rotation of the sample containers around the axis of rotation. As will be recognized, any suitable number of cell cavity 80a may be used. In one embodiment, as with the rotor 12 in Figure 4, the rotor body 70a is constructed of carbon fiber material. For example, the rotor body 70a may be compression molded from layers of resin-coated carbon fiber laminate material.

[0051] In the embodiment shown, the rotor body 70a and the rotor insert 82a are co-molded within the hole 72a. The insert 82a includes a threaded hole 84a to securely mount the rotor body 70a on the hub 14a, for at least to receive the threaded outer intermediate surface 26a of the shaft portion 22a of the hub 14a and to engage with the outer intermediate surface 26a in a manner that screws into it.

[0052] With the rotor body 70a mounted on the rotor hub 14a, a hub retainer 90a is removably fastened to the hub 14a to further facilitate holding the rotor body 70a, the hub 14a, and the insert 82a in a fixed position relative to each other. The hub retainer 90a includes at least a threaded hole 92a to receive the threaded outer end face 24a of the shaft portion 22a of the hub 14a and to engage with the outer end face 24a in a manner that screws into it.

[0053] The rotor 12a also includes a lid 100a that is removably coupled to the rotor hub 14a above the rotor body 70a to assist in holding the sample container within it while the rotor body 70a is rotating, for example. The lid 100a is substantially disc-shaped and includes a central hole 102a and a peripheral groove 104a, the peripheral groove 104a being for receiving an O-ring 106a to provide a fluid seal between the lid 100a and the rotor body 70a when the lid 100a is removably coupled to the rotor body 70a. In one embodiment, the lid 100a is constructed of carbon fiber material. For example, the lid 100a may be compression-molded from layers of resin-coated carbon fiber laminate material.

[0054] Similar to the lid 100 in Figure 4, the lid 100a may be removably coupled to the rotor body 70a via a lid screw 110a. The illustrated lid screw includes an upper flange 112a, a threaded lower outer surface 114a, and a multi-stage hole 116a. As shown, the threaded lower outer surface 114a is received by and engages with the threaded inner surface 32a of the hub 14a in a screw-in manner, thereby causing the upper flange 112a to press the spacer 118a against the lid 100a. When the lid 100a is removably coupled to the rotor body 70a via the engagement of the lid screw 110a with the hub 14a and the engagement of the spacer 118a with the lid 100a, it prevents access to the sample container held in the cavity 80a, such as during high-speed rotation. A tie-down screw or pin 120a may be inserted through the hole 116a of the cover screw 110a and coupled in a manner that it screws onto the knob 122a. The tie-down pin 120a may be configured to engage with a cooperating hole in a centrifuge spindle (not shown), which then assists in mounting the rotor 12a to the centrifuge spindle. As shown, the tie-down pin 120a may be biased away from the centrifuge spindle by a helical spring 124a. The threshold force of the helical spring 124a may be overcome, prompting the tie-down pin 120a to engage with the hole in the centrifuge spindle, which can then be actuated to drive the rotor 12a to high-speed centrifugal rotation. As with the centrifuge rotor 12 and hub assembly 10 in Figure 4, as will be apparent to those skilled in the art, one or more of the rotor mounting components described above may be made of any suitable metallic or non-metallic material.

[0055] While various embodiments have been described in considerable detail, illustrating different aspects of the principle of this invention, these embodiments are not intended to limit the scope of the invention to such details or impose any limitations. The various features shown and described herein can be used individually or in any combination. Additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the invention in its broadest mode is not limited to the specific details shown and described, representative apparatus and methods, or exemplary examples. Thus, deviations from such details can be made without departing from the general concept of the invention.

Claims

1. A centrifuge rotor, A rotor body having multiple tubular cavities, each configured to receive a sample container inside, This includes a rotor hub assembly for the centrifuge rotor, The rotor hub is configured to transmit torque from the centrifuge spindle to the rotor body. The rotor hub assembly is A rotor hub comprising a head, an elongated shaft portion extending axially away from the head, and a central hole extending through the head and the shaft portion, Includes a ring fastened to the head, The head includes a plurality of balance holes, each configured to selectively receive at least one balance weight, and the ring encloses the balance weight, wherein the rotor is a centrifugal separator.

2. The centrifuge rotor according to claim 1, wherein the balance weight of the head is positioned within the internal space of the lower cavity of the centrifuge rotor, spaced apart from the sample container of the centrifuge rotor.

3. The centrifugal separator rotor according to claim 1, further comprising at least one balance weight received by at least one of the plurality of balance holes.

4. The centrifugal separator rotor according to claim 3, wherein the at least one balance weight includes at least one set screw having at least one threaded outer surface.

5. The centrifuge rotor according to claim 3 or 4, wherein the at least one balance weight is selected to balance the centrifuge rotor during centrifugal separation by the centrifuge rotor.

6. The centrifugal rotor according to any one of claims 1 to 5, wherein the head includes a plurality of fastening holes, each configured to selectively receive fasteners for attaching at least one ring to the rotor hub.

7. The centrifugal separator rotor according to claim 6, wherein each of the balance holes is of the first configuration, and each of the fastening holes is of a second configuration different from the first configuration.

8. The centrifugal rotor according to any one of claims 1 to 7, further comprising at least one ring attached to the rotor hub and covering the at least one balance weight.

9. The centrifugal rotor according to claim 8, wherein the at least one ring includes at least one of a magnetic ring or an annular shield.

10. The centrifugal separator rotor according to any one of claims 1 to 9, wherein the plurality of balance holes have a uniform configuration.

11. The centrifugal separator rotor according to any one of claims 1 to 10, wherein the plurality of balance holes are arranged on the head of the rotor hub at intervals from each other in the circumferential direction.

12. The centrifugal separator rotor according to any one of claims 1 to 11, wherein each of the plurality of balance holes is threaded.

13. The centrifugal separator rotor according to any one of claims 1 to 12, wherein the plurality of balance holes include eight balance holes.

14. The centrifugal separator rotor according to any one of claims 1 to 13, wherein the rotor hub is constructed of a metal material.

15. A method for operating a centrifuge rotor according to any one of claims 1 to 14, comprising a rotor body having a plurality of tubular cavities and a rotor hub having a plurality of balance holes, wherein each balance hole is configured to selectively receive at least one of a plurality of balance weights, To detect an imbalance in the centrifuge rotor, A method comprising selectively engaging at least one of the plurality of balance weights with at least one of the plurality of balance holes in response to the detected imbalance.

16. The method according to claim 15, further comprising identifying at least one target position on the rotor hub and at least one corresponding target weight amount to be added to the at least one target position on the rotor hub, in order to balance the centrifugal rotor.

17. The method according to claim 16, further comprising selecting at least one of the plurality of balance holes and at least one of the plurality of balance weights, depending on at least one identified target position and at least one corresponding target weight amount, respectively.

18. The method according to any one of claims 15 to 17, wherein selectively engaging at least one of the plurality of balance weights with at least one of the plurality of balance holes includes engaging the at least one balance weight in a manner such as screwing it into at least one of the balance holes.

19. The method according to any one of claims 15 to 18, further comprising rotating the centrifuge rotor for centrifugal separation with the at least one balance weight selectively engaged with at least one balance hole.

20. The method according to claim 19, further comprising selectively disengaging the at least one balance weight from at least one of the balance holes after centrifugal separation.

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