Rotor for a centrifuge and centrifuge

Abstract

Rotor (20) for a centrifuge (1), which is set in rotation by a drive source (9), comprising: a rotor body (21) in which a recess (22) is formed; a rotor core (40) which is arranged in the recess (22); and a rotor cover (30) for closing an opening of the rotor body (21), characterized in that the rotor core (40) comprises: a column-shaped solid section (41); a disc section (44) extending radially outwards from an upper surface of the solid section (41); a liquid supply groove (50) arranged on an upper surface of the rotor core (40) and extending continuously from the solid section (41) to the disk section; and a liquid supply opening designed to extend downwards from the upper surface of the solid section (41) and further in a radial direction, and a stress relief groove (57, 158) which is formed on a lower surface of the disc section (44).

Description

BACKGROUND Technical Area

[0001] The present invention relates to a rotor for a centrifuge which injects a sample from the outside of a device during rotation of the rotor and collects a centrifuged sample outside the device during rotation of the rotor, and relates to a centrifuge which uses the same. State of the art

[0002] A centrifugal separator contains a rotor (rotating body) within a rotor chamber (rotation chamber). The rotor holds a sample to be separated and is rotated at high speed by a drive device such as a motor or similar, while a section of the rotor chamber is closed by a door. This process separates and cleans the sample held in the rotor, or performs other operations. In normal use, when the rotor's rotation has stopped, the sample to be separated is placed in a sample container and held by the rotor. The rotor is then rotated by the drive device after the rotor chamber door is closed. Once the centrifugal separation process is complete, the rotor stops rotating, the door is opened, and the sample container is removed.

[0003] Another centrifugal separation method used in medicine, pharmaceuticals, and similar fields involves a continuous rotor system. In this system, a sample is separated from the outside of a centrifuge body by being continuously and directly fed into a rotor via a tube. Examples of continuous rotor designs are shown, for instance, in patent literature 1 and patent literature 2. When using a continuous rotor, a sample container is positioned outside the centrifuge body. A sample flow path is formed by a tube extending from the container to the rotor, which is located in a rotor chamber of the centrifuge body. The sample to be separated is continuously fed from the sample container into the rotor while the rotor rotates.

[0004] In the centrifugal separator, which uses a continuous rotor, an adapter is located at the door separating the inner and outer chambers of the centrifuge body. This adapter allows a sample tube to be inserted from the outside of the centrifuge body into the rotor chamber. The adapter enables the introduction and discharge of a liquid, such as a density gradient fluid, a sample, or similar, into and out of the rotor's interior from near an axial center on the top of the rotating rotor. The rotor has various shapes, such as a shell with a lid (rotor cap), and an element called the rotor core is positioned inside the rotor to direct the flow of the introduced and discharged liquid in a predetermined direction. The rotor core also comes in various shapes.In one example, the top of the rotor core is brought into close contact with the rotor cover, and several grooves are formed in the top for the supply of the density gradient fluid, extending radially outwards from near the center of the central axis. [Literature on the state of the art][Patent literature] Patent literature 1: Disclosed Japanese utility model JP S60 - 119 946 U. Patent Literature 2: Japanese Patent Disclosure No. JP 2010 - 82 567 A. Patent literature 3: DE 12 37 360 A. SUMMARY [Problems to be solved]

[0005] Since the rotor core used in the continuous rotor is located inside the rotor and rotated at high speed in a state where the rotor's interior is filled with a fluid such as the density gradient fluid, the sample, or similar, a stress caused by hydraulic pressure generated by centrifugal separation is concentrated on a specific point of a groove section formed in the rotor core, e.g., the fluid feed groove radially formed in the upper surface. This stress acts in a direction that deforms the area surrounding the groove section of the rotor core, so the rotor core must possess sufficient strength to withstand the stress. In addition to strength, it is also important that the rotor core has a sufficient service life to withstand repeated use.

[0006] The present invention has been completed in consideration of the above background, and the objective is to provide a rotor for a centrifuge which suppresses the deformation of a rotor core by averaging a load which is locally applied by a hydraulic pressure which is applied to a liquid supply groove which is formed in the upper surface of the rotor core, and to provide a centrifuge which uses the rotor for a centrifuge.

[0007] Another object of the present invention is the provision of a rotor for a centrifuge which has a sufficient span in service life by suppressing the deformation of a rotor core, and a centrifuge which uses the rotor for the centrifuge. [Means of solving the problems]

[0008] Typical features of the invention disclosed in the present application are described below.

[0009] According to a feature of the present invention, a rotor for a centrifuge, which is rotated by a drive source, comprises a rotor body having an internally formed recess, a rotor core arranged in the recess, and a rotor cover for closing an opening in the rotor body. The rotor core comprises: a column-shaped solid section; a disk section extending radially outward from an upper surface of the solid section; a liquid feed groove arranged in an upper surface of the rotor core and configured to extend through from the solid section to the disk section; and a liquid feed opening configured to extend downward from the upper surface of the solid section and further in a radial direction. A stress relief groove is formed in a lower surface of the disk section.The rotor core is a single-piece element made of resin or metal, and an upper opening section of the fluid supply groove is sealed by contact with an inner lower wall of the rotor cover. The stress relief groove is located on a section that partially overlaps the position of the fluid supply groove when the disk section is viewed along an axis. Furthermore, the stress relief groove is a groove that extends in a straight line radially from an inner circumferential side to an outer circumferential side on the lower surface of the disk section and is configured such that an end section on the outer circumferential side reaches an outer edge section of the disk section.

[0010] According to a further feature of the present invention, several liquid supply grooves are formed at equal intervals in a circumferential direction, and the load-release groove is configured in a manner corresponding to the multiple liquid supply grooves. For example, the liquid supply groove has a U-shaped cross-section orthogonal to a direction of extension, and the load-release groove has a rectangular, U-shaped, or V-shaped cross-section orthogonal to the direction of extension. Furthermore, a depth D2 of the load-release groove satisfies the condition D1 + D2 < T, where T is the thickness of the disk section and D1 is the depth of the liquid supply groove. In this way, multiple load-release grooves are distributed circumferentially or radially with respect to each of the liquid supply grooves.Furthermore, blades are arranged that extend radially outwards from an outer circumferential surface of the solid section. These blades have the form of a vertical plate connected to the disk section, and the solid section and the blades are either formed as one piece or separately.

[0011] According to a further feature of the present invention, a column-shaped projection, which projects axially upwards, is formed in an axial center of the upper surface of the solid section. The liquid supply groove consists of four axial groove sections extending downwards in an outer circumferential surface of the projection, and a radial groove section extending radially outwards from the lower end of the axial groove section with respect to the solid section.Furthermore, the fluid supply opening has a first fluid supply opening, which has an upper opening in the axial center of the upper surface of the projection, extends downwards in the axial direction and outwards in the radial direction in the center, and opens near the lower surface of the disk section on the outer circumferential surface of the solid section, and a second fluid supply opening, which has an opening at a position next to the outside in the radial direction from the upper opening of the first fluid supply opening, extends downwards in the axial direction and outwards in the radial direction in the center, and has an opening in the outer circumferential surface of the solid section.A centrifuge is configured using the centrifuge rotor, configured as above; a door adapter, mounted on the rotor cover and having a through-hole through which a flow path, supplying and removing a liquid to and from the recess, passes; a tray defining a rotor chamber in which the centrifuge rotor rotates; and a housing to hold the drive source and the tray. [Effect]

[0012] According to the present invention, the load relief groove is formed in the lower surface of the disc section of the rotor core, which extends in a radial direction, at a position that partially overlaps the position of the fluid supply groove, and thus the concentration of the load that is locally applied can be relieved by the fluid supply groove formed in the upper surface of the rotor core, the deformation of the rotor core during high-speed rotation can be suppressed, and the service life of the rotor core can be extended. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is an overall configuration diagram of a centrifuge 1 according to an embodiment of the present invention. Fig. Figure 2 is an enlarged view of a rotor 20 made of Fig. 1. Fig. Figure 3 is a perspective view of a rotor core 40 made of Fig. 2, viewed diagonally from below. Fig. Figure 4 is a perspective view of the rotor core 40 of Fig. 2 in oblique view from above. Fig. 5 (A) is a partial side view of a disk section 44 of the rotor core 40, seen from a section B of Fig. 4, and (B) of Fig. 5 and (C) of Fig. Figure 5 shows partial cross-sectional views to illustrate the stress on the liquid supply grooves 152 and 52. Fig. Figure 6 is a schematic view of the rotor 20 to illustrate a liquid supply state of a density gradient liquid during a centrifugal separation process. Fig. Figure 7 is a schematic view of the rotor 20 to illustrate a liquid supply state of a sample during the centrifugal separation process. Fig. Figure 8 is a schematic view of the rotor 20 to illustrate a discharge state of a separated sample during the centrifugal separation process. Fig. Figure 9 shows a partial top view and a partial side view to illustrate a liquid supply groove according to an embodiment of the design. Fig. Figure 10 shows a partial top view and a partial cross-sectional view to illustrate the liquid supply groove according to the exemplary embodiment of the design. Fig. Figure 11 shows a partial top view and a partial cross-sectional view to illustrate a liquid supply groove according to an embodiment of the design. Fig. Figure 12 shows diagrams of a rotor core 140 of a conventional centrifuge, (A) of Fig. Figure 12 is a perspective view of the rotor core 140 when viewed obliquely from below, and (B) of Fig. Figure 12 is a perspective view of the rotor core 140 when viewed obliquely from above. DESCRIPTION OF THE EXECUTION FORMS

[0013] An embodiment of the present invention is described below with reference to the drawings. It should be noted that in the following figures the same parts are designated with the same reference numerals and that repeated descriptions are omitted. Furthermore, the directions up, down, left, and right are described as corresponding to the directions shown in the diagrams.

[0014] Fig. Figure 1 is a cross-sectional view showing the overall structure of a centrifuge 1 according to an embodiment of the present invention. In the centrifuge 1, an interior of the housing 2, which consists of a box-shaped sheet or the like, is divided into an upper and a lower chamber by a partition plate 13, and a tray 3 formed from a thin metal plate is arranged in the upper chamber. A rotor chamber 4 is formed by closing an opening section of the tray 3 with a sliding door 18. A rotor 20 is a so-called rotating body for continuous centrifugal separation, which allows the insertion and removal of a sample to be separated during rotation and is mounted on a rotating shaft 10 of a motor 9 serving as a drive device. The motor 9 is attached to the partition plate 13, which forms part of the housing 2, via a damper 12. Foot elements 16 are arranged on the underside of the housing 2.

[0015] The shell 3 is made of a material such as stainless steel, an aluminum alloy, a copper alloy, or similar, and has a substantially circular cross-section in the horizontal direction and a substantially bowl-like shape with an opening at the top. A cooling device 14 for cooling the rotor chamber 4 in order to cool (maintain) the rotor 20 at a set temperature is arranged on a bottom surface of the shell 3. A metal protector 8, with a thickness of a few millimeters to several tens of millimeters, is arranged on the outside of the shell 3.

[0016] A ring 11 is arranged at the upper end of the rotating shaft 10 of the motor 9, and a rotating shaft bore 25 of the rotor 20 is positioned such that it engages with the ring 11. A control device 15 for controlling the operation of the motor 9 or the like is arranged inside the housing 2. The control device 15 contains a microprocessor, and the rotation of the motor 9, the operation of the cooling device 14, and the supply and discharge of a density gradient liquid, a sample, or the like are controlled by executing a computer program. A display device, such as a liquid crystal display (not shown) or the like, is arranged on an upper surface of the housing 2.

[0017] A door adapter 70, containing a sealing element, is located on the top of the rotor 20. The door adapter 70 is a stationary element, and a sealing attachment containing the sealing element 71 is supported by a through-hole 18a in the door 18. A sample inlet / outlet 72, a density gradient fluid inlet 73, and a water outlet 74 of a cooling water tube are located on the sealing element 71. Although not shown, a tube (not shown) for supplying and removing a sample and the density gradient fluid is connected to the sample inlet / outlet 72, and a tube for supplying the density gradient fluid is connected to the density gradient fluid inlet 73. The water outlet 74 is connected to a tube (not shown) for circulating cooling water that cools a sealing element (not shown).

[0018] The rotor 20 receives a sample to be separated and separates the sample into layers in a radial direction by being set in rotation by the motor 9. A rotor body 21 has the shape of a shell. A screw thread is formed on an upper end section on the outer circumference of the shell shape, and the rotating shaft bore 25, which is attached to the rim 11 fixed at a front end (upper end) of the rotating shaft 10, is formed on a bottom surface. A core (rotor core 40) is arranged on the inside of a recess 22, which is set back inwards from an upper opening of the rotor body 21, and the opening is closed by a cover 30. The rotor core 40 has a blade 58 (see Fig. 2 to 4, which will be described later), which serves as a partition that divides a partition chamber 24 into four sections which, viewed from above, have a fan shape.

[0019] The lid 30 has an inner screw that is attached to the outer screw of the rotor body 21 and receives the sample by closing the open part of the cup-shaped rotor body 21 and the separation chamber 24 (see Fig. 2 for the reference numeral) is closed by the lid 30 and the rotor body 21. In the centrifuge 1 according to the invention, not only the so-called rotor 20 can be used for continuous centrifugal separation, but also a general angle rotor or a tilting rotor. The angle rotor has mounting holes for attaching a plurality of test containers in a circumferential direction. When the angle rotor is mounted on the ring 11, the in Fig. 1 Door adapter 70 shown removed and the passage opening 18a of door 18 closed.

[0020] Fig. Figure 2 is an enlarged view of the rotor 20. The rotor 20 consists of the cup-shaped rotor body 21, the rotor core 40 for guiding the liquid to predetermined radial and axial positions of the separation chamber (receiving section) 24 and for drawing the liquid from these predetermined radial and axial positions, and the cover 30, which closes the upper opening of the rotor body 21. The rotor body 21 is formed by integral casting of a metal, such as a titanium alloy or similar material. An external screw (not shown) is formed on the outer circumferential section of the upper opening section of the rotor body 21, and the rotating shaft bore 25, which is attached to the rim, is formed on a bottom surface.

[0021] The cover 30 is a one-piece element made of a metal, such as a titanium alloy or similar, and consists of a disk surface 31 arranged on the same surface as an opening surface of the rotor body 21, and a cylindrical surface 32 extending downwards from an outer edge section of the disk surface 31. An internal screw is formed on the inner circumferential side of the cylindrical surface 32, which is attached to the external screw formed on the side of the rotor body 21. The cover 30 receives the sample by closing the open part of the cup-shaped rotor body 21, and the separation chamber 24 is formed in the interior of the cover 30 and the rotor body 21. To improve airtightness, a sealing packing 28 is arranged at a connection section between the cover 30 and the rotor body 21.Furthermore, a through-bore 30a for a shaft 35 is formed in a central axial section of the cover 30, into which it can be inserted. The shaft 35 is fastened to the cover 30 with a nut (not shown). A double tube is formed, in which an outer tube is formed on the outside of an inner tube, and a passage is formed in which the inner tube is connected to a central axial hole 45 of the rotor core 40, and the outer tube is connected to an inverted funnel-shaped flow path section 34, which has an upside-down funnel shape and is formed on the lower surface on the central axis line of the cover 30. The inverted funnel-shaped flow path section 34 serves as part of a passage for supplying and discharging the density gradient fluid, a buffer fluid, or the like.

[0022] The rotor core 40 essentially consists of a substantially cylindrical solid section 41 and an annular disk section 44, which extends radially outward in a flange-like shape on the same surface as an upper surface of the solid section 41. The solid section 41 and the disk section 44 are formed by integral casting of resin or metal. The solid section 41 is not completely columnar, and its diameter is shaped such that the outer diameter decreases slightly from the top to the bottom. A columnar projection 43 is formed in the center of an upper surface of the rotor core 40, projecting upward in a convex shape and engaging in a columnar recessed section (a recess 37) formed in the cover 30.In the center of a lower surface of the rotor core 40, a recess 42a is formed, which is convexly concave upwards and engages in a projection 23 that is formed near the central axis of a bottom surface of the rotor body 21 and projects upwards. An O-ring 27 is arranged between the recess 42a and the projection 23 and seals to prevent fluid from leaking from the lower end of a central shaft hole 45, indicated by an arrow 45c, to the underside of a stage section 42.

[0023] A fluid supply groove (radial groove) 52 is formed in the upper surface of the rotor core 40. This groove serves to supply fluid and extends in a radial direction. An outer peripheral side end section of the fluid supply groove 52 extends to a position that essentially reaches the inner wall surface of the recess in the rotor body 21. The fluid supply groove 52 is formed on an upper surface of the disk section 44, and a stress relief groove 57 is formed on a lower surface of the disk section 44, corresponding to the position of the fluid supply groove 52.

[0024] The central axis hole 45 is formed concentrically to a rotational axis A1 of the rotor core 40. The central axis hole 45 is formed by drilling in a manner that extends from a position indicated by arrow 45a on the upper surface of the rotor core 40 to a position indicated by arrow 45c on the lower surface. Furthermore, a radial hole 46 is formed obliquely in the lower surface of the rotor core 40, extending from near a position indicated by arrow 46a to a position indicated by arrow 45b in the center of the central axis hole 45. In total, four radial holes 46 are formed at equal intervals and at 90-degree intervals in the circumferential direction (in Fig. (Only two holes are visible due to the cross-sectional position). The radial bore 46, like the central axle hole 45, can also be produced by drilling.

[0025] Although in the vertical cross-sectional position in Fig. 2. Due to different arrangement positions in the circumferential direction, the rotor core 40 contains an essentially L-shaped through-hole 47 (schematically shown in...). Fig. 7 shown) formed, which connects an upper surface of the projection 43 with the vicinity of the upper end of the massive section 41, indicated by an arrow 41b.

[0026] Fig. Figure 3 is a perspective view of the rotor core 40, seen obliquely from below. The rotor core 40 is arranged to form a passage for the sample or the density gradient fluid in the rotor body 21 and is manufactured by integral molding of a synthetic resin or metal. The four blades 58 formed on the rotor core 40 are shaped to prevent turbulence of the sample and the density gradient fluid in the separation chamber 24 (see Figure 3). Fig. 2) An outlet opening of the liquid supply groove 52 is located at an outer edge section of the disk section 44. To ensure that the liquid discharged radially outwards from the liquid supply groove 52 effectively flows into the lower space, a slightly inwardly concave, arc-shaped section 56 is formed near the opening of the liquid supply groove 52 of the disk section 44. The design of the concave section 56 ensures that the flow path is not restricted even when an outer circumferential surface of the disk section 44, with the exception of the concave section 56, is in close contact with an inner circumferential sidewall surface of the rotor body 21. An opening 47a of an L-shaped hole 47 is located near the upper end of the solid section 41, as indicated by arrow 41b, and is positioned directly below the disk section 44.An opening of the L-shaped hole 47 on the other side opens onto the top of the projection 43 (see . Fig. 2), which is formed on the central axis on the top side of the rotor core 40.

[0027] An opening 46a of the radial hole 46, which is connected to the central axial hole 45 (see Fig. 2) is connected, is formed in a lower surface of the solid section 41 of the rotor core 40. As shown in the cross-sectional view of Fig. As shown in Figure 2, the radial hole 46 is shaped more obliquely than horizontally, and it slopes upwards when approaching the axis of rotation A1. The fluid does not flow when the four openings 46a are in close contact with the base surface of the rotor body 21 (see Figure 2). Fig. 2) Therefore, the stepped section 42, which projects slightly downwards, is formed on the underside of the solid section such that a gap remains between the outer edge of a bottom surface of the solid section 41 and the rotor body 21. By forming the stepped section 42 in this way, the sample can be smoothly fed into or out of the separation chamber 24 through a first liquid inlet opening using the radial hole 46 (see Fig. 2) flow. Furthermore, the radial opening 46 is the first liquid supply opening and the L-shaped opening 47 is a second liquid supply opening, which are independent flow paths.

[0028] Here, the shape of a conventional rotor core 140 is described with reference to Fig. 12 described. The conventional rotor core 140 has a solid section 141 and a disk section 144 extending radially outward from an upper surface of the rotor core 140. In addition, a titanium sleeve 160 made of a titanium alloy is attached to an outer circumferential surface of the solid section 141. A resin blade (not shown) is attached to the outer circumferential side of the titanium sleeve 160, and the conventional rotor core 140 has an overall shape similar to that of the rotor core 40 described in Fig. The embodiment shown in Figure 3 corresponds to the titanium sleeve 160, which is used to reinforce the solid section 141 and is fitted into it. A resin blade (not shown) can be attached to the outer circumferential side of the titanium sleeve 160. The blade (not shown) has almost the same shape as the one shown in Figure 3. Fig. 3 Blade 58 shown. A first fluid supply opening (a radial hole 146) and a second fluid supply opening (an L-shaped hole 147), which are the same as those in Fig. The features shown in Figure 3 are also formed in the conventional rotor core 140. Furthermore, four radially extending fluid supply grooves 152 are formed in an upper surface 144a of the solid section 141 and the disk section 144. A projection 143 is formed in the center of the upper surface of the solid section 141, and the shape of the solid section 141 and the positions of the holes and grooves formed on it are the same as in the figures shown. Fig. 2 and Fig. 3 shown. However, as shown. Fig. As can be seen in Figure 12(A), a lower surface 144b of the disk section 144 is flat and has no grooves or depressions formed therein.

[0029] The difference between the rotor core 40 and the one in Fig. The difference in the conventional rotor core 140 shown in Figure 12 is that the blade 58 is also contained within the rotor core 40 and is formed integrally with the rotor core 40, and that the stress relief groove 57 is formed in the lower surface of the disk section 44. The stress relief groove 57 is formed on the underside of the fluid supply groove 52, which is formed in the upper surface of the disk section 44. The stress relief groove 57 is arranged such that it partially overlaps a position where the fluid supply groove 52 is formed when viewed in the direction of axis A1. Furthermore, the radial outer end section of the stress relief groove 57 opens into the recessed section 56.At the radial inner end section of the load relief groove 57, a smooth edge section is formed in a spherical shape, as shown by arrow 57a, in order to avoid as much as possible a concentration of the load at a particular bending point.

[0030] Fig. Figure 4 is a perspective view of the rotor core 40 in an oblique top view. The top of the rotor core 40 is formed by the top of the solid section 41, shown by a dashed line, and a plane on which the disk sections 44 formed on the outside in a radial direction are continuous. The upper opening 45a of the central shaft hole 45 is formed near the center of the shaft on the upper surface of the solid section 41. The upper opening 45a is also an opening section of the first fluid supply opening. Four upper openings 47c are formed around the upper opening 45a. The upper openings 47c are located in the upper surface of the projection 43 and are directed slightly outwards in a radial direction from the axis of rotation A1. Since the shaft 35 (see Figure 4) Fig. 2) is guided through the upper opening 45a, an independent flow path is maintained which cannot be confused with a flow path through the upper opening 47c.

[0031] A passage, primarily for supplying the density gradient fluid or the like into the separation chamber, is formed by fluid supply grooves 51 and 52, which are formed in the upper surface of the rotor core 40. Fluid supply groove 51 is a groove section that extends from top to bottom along the outer circumferential surface of the projection 43 and serves as a closed passage when the projection 43 abuts the recess 37 of the cover 30. Fluid supply groove 52 is a groove section that extends from the inside to the outside in a radial direction along the outer circumferential surface of the projection 43 and serves as a closed passage when the upper surface of the rotor core 40 abuts the inner lower surface of the cover 30.The arc-shaped section 56, which is recessed radially towards the inside, is arranged at the radially outer end section of the liquid supply groove 52, and the liquid that reaches the outer section in a radial direction through the liquid supply groove 52 flows to the separation chamber 24 (see . Fig. 2) on the underside. Four radially connected blades 58 are integrally formed on the outer circumferential surface of the solid section 41 of the rotor core 40. These blades 58 divide the interior of the separation chamber 24 (see Fig. 2) into four rooms. As in Fig. As shown in Figure 3, the opening 46a of the radial hole 46 (the first liquid supply opening) and the opening 47a of the L-shaped hole 47 (the second liquid supply opening) are arranged in each of the four separate spaces.

[0032] In the upper surface of the rotor core 40, four holes 49 are arranged at equal intervals in the circumferential direction at the upper end section of the solid section 41. These holes 49 are shaped so that they engage with a special clamping device when the rotor core 40 is removed from the rotor body 21.

[0033] Fig. Figure 5 is a partial side view of the disk section 44 of the rotor core 40. Fig. 4, as seen from a B section. The thickness of the disk section 44 is T, and the cross-sectional shape of the fluid supply groove 52, which extends radially from the inside out in the upper surface 44a of the disk section 44, has a semi-oval shape, resembling a half-oval. The inner end section of the fluid supply groove 52 is connected to the fluid supply groove 51, which extends along the axis. The fluid supply groove 51 is a groove that is recessed into the outer circumferential surface of the projection 43 on the inner circumferential side. In the embodiment, the stress relief groove 57, which extends radially from the inside out in the lower surface 44b of the disk section 44, is formed at the circumferential position corresponding to the fluid supply groove 51 (e.g.,The fluid supply groove 51 is located approximately in the same position on the lower surface of the disc section 44. The stress relief groove 57 also has the same shape as the fluid supply groove 52, and its cross-sectional shape is a semi-oval, resembling half an oval. The stress relief groove 57 is a groove that extends in the direction of the fluid supply groove 51. It is desirable that the depth D1 of the fluid supply groove 52 be deeper in the direction of the sheet thickness than the depth D2 of the stress relief groove. However, the depth D1 of the fluid supply groove 52 depends on various conditions, such as the shape, hydraulic pressure, and the like; therefore, the optimal shape is determined after the strength has been sufficiently verified.However, it is necessary that D1 + D2 is sufficiently smaller than the thickness T and that a sufficient distance remains between the fluid supply groove 52 and the stress relief groove 57. The circumferential width W1 of the fluid supply groove 52 is designed to be constant in the radial direction from the inside to the outside. Similarly, the width W2 of the stress relief groove varies depending on various conditions such as shape, hydraulic pressure, and the like, and the optimal shape is thus determined after the strength has been sufficiently verified.

[0034] Here, the manner in which load fluctuations are generated due to the presence of the groove section (the liquid supply groove 52) is described with reference to the Fig. 5(B) and Fig. 5(C) described. Fig. 5(B) shows a liquid supply groove 152 of the in Fig. The conventional rotor core 140 shown in Figure 12. In the fluid supply groove 152, the fluid injected into the rotor core 40, such as the density gradient fluid, the sample, or similar, exerts a uniform hydraulic pressure on positions with the same radius. However, since the hydraulic pressure caused by the high-speed rotation of the rotor 20 is also exerted on the wall surface of the groove section (the fluid supply groove 152) in the directions of arrows 65a and 65b, with the corner of the groove section acting as the pivot point, a moment is generated that bends the area around the center of the groove upwards into a convex shape, as shown by arrows 66a and 66b. Thus, a force acts during rotation that deforms the fluid supply groove 152 upwards into a convex shape. Therefore, during the Fig. In the embodiment shown in Figure 5(C), a moment is also generated on the underside of the disk section 44 by forming a groove section (the load relief groove 57), which bends the groove section (the load relief groove 57) downwards, as shown by the dashed arrows 68a and 68b, using the hydraulic pressure acting on the lower groove section (the load relief groove 57), as shown by the dashed arrows 67a and 67b, and thereby the moments (66a, 66b) generated by the upper groove and the moments (68a, 68b) generated by the lower groove are practically canceled out to suppress the deformation, and the load in the upper and lower groove sections is relieved, which reduces the deformation of the disk section 44.In this way, by reducing the deformation of the core during rotation, the effect of material fatigue due to repeated use can be reduced and the service life of the rotor core 40 can be extended.

[0035] The following describes the feed and discharge states of the density gradient liquid or sample during the centrifugal separation process with reference to the Fig. 6 to 8 described. Fig. Figure 6 is a diagram showing the state of the density gradient fluid supply during a preparation phase before the sample is injected into rotor 20. In each of the Fig. Figures 6(A) to 8(A) show the liquid supply groove 52 and the first liquid supply opening (the radial hole 46) enlarged so that the liquid flow is visible. The second liquid supply opening (the L-shaped hole 47) is shifted to the circumferential position to be visible in the same cross-sectional view. These figures are schematic views and do not correspond to the actual scale and arrangement. In particular, it should be noted that the shape of the rotor core 40 is shown smaller and the size of the individual passages is enlarged.

[0036] One step of the sample injection process is described. When the process is initiated by an operator using a display panel (not shown), the control device 15 rotates the motor 9 and turns the rotor 20 at a speed of approximately 3,000 rpm. At this point, the control device 15 actuates the cooling device 14 to cool the temperature inside the rotor chamber 4 to a predetermined temperature. Subsequently, the control device 15 (not shown) uses the outer passage of the double channel, which penetrates the central axis of the cover 30, to supply the density gradient fluid, as indicated by arrow 81a. Fig. In Figure 6(A), the symbols are only marked on the black arrows on the left. However, since the rotor is rotationally symmetric, the fluid flows into the separation chamber 24 on the right side of the diagram in the same manner. The density gradient fluid, flowing as shown by arrow 81a and reaching part of a space 36 on the top of the projection 43, flows due to centrifugal force along the outer circumferential surface of the inverted funnel-shaped flow path section 34, which is formed in a funnel shape, and flows into the fluid inlet grooves 51 and 52, as shown by arrows 81b to 81d. Since the rotor 20 rotates at a speed of 3,000 rpm, the fluid here flows due to centrifugal force along the outer circumferential surface and thus does not flow into the L-shaped opening 47.The liquid that has flowed to the outer edge of the liquid supply groove 52 flows into the separation chamber 24, as shown by arrows 82a and 82b. In this way, the density gradient liquid is filled into the separation chamber 24, and at this point, layers of liquids with different densities are formed in the separation chamber 24 by the exchange and flow of the density gradient liquid with different specific gravities. When the interior of the separation chamber 24 is filled with the density gradient liquid, the excess density gradient liquid, which has a low specific gravity, is moved as shown by arrows 83a to 83c and 84a to 84c, forced out through the radial opening 46, as shown by arrow 85, towards the center, and flows through the central shaft hole 45, as shown by arrows 86, 86a, and 86b, to be discharged to the outside of the rotor 20.In this way, the density gradient liquid required for sample separation is injected from the outside of the rotor 20 using a liquid feed pump (not shown) and discharged from the shaft 35.

[0037] Next, with reference to Fig. 7. A centrifugal separation step is described. The flow path is determined by the injection state of the in Fig. The density gradient fluid shown in Figure 6 is switched to, the rotational speed of the rotor 20 is increased to 32,000 to 35,000 rpm, and, as shown by arrow 87a, the sample is fed from the inside of the shaft 35 using the fluid feed pump (not shown). The sample, flowing through the central shaft hole 45 and the radial bore 46, as shown by arrows 87a to 87c, passes through the gap between the lower surface of the solid section 41 of the rotor core 40 and the lower surface of the rotor body 21, as shown by arrow 87d, and flows into the separation chamber 24. In the separation chamber 24, the high-density component moves to the outer circumferential side and the low-density component moves to the inner circumferential side due to the centrifugal force of the high-speed rotating rotor 20.Since the sample flows continuously, as shown by arrows 87a to 87d, the component with a lower specific gravity moves on the inner circumferential side of the separation chamber 24 towards the inside of the opening 47a of the L-shaped hole 47, as shown by arrow 87f, is then discharged from the upper opening 47c formed on the projection 43, as shown by arrow 87g, and is finally discharged outwards by the rotor 20, as shown by arrow 87h. While the sample flows continuously into the rotor 20 in this manner, the process is carried out for a time suitable for centrifugal separation.

[0038] Fig. Figure 8 is a diagram illustrating a procedure for extracting a separated sample component (separated sample 90) after completion of the centrifugal separation process. The rotor 20 is decelerated back down to 3,000 rpm. Then, a high-density extrusion fluid is injected from a sample outlet opening, as indicated by arrows 88a to 88d. Subsequently, the extrusion fluid is injected into the separation chamber 24, as shown by arrow 88e, causing the separated sample component to be extracted from the separation chamber 24 to be extruded from the outer circumferential side, as shown by arrows 90a to 90c, towards the inner circumferential side. The density gradient liquid on the inner circumferential side of the separated sample 90 is drained out of the shaft 35 as shown by arrows 91a to 91c, 92, 93a and 93b.When the extrusion fluid is injected, the separated sample 90 is discharged along the inner circumferential side following the density gradient fluid, and thus the separated sample 90 is collected. The density gradient fluid containing precipitated particles can be collected separately by a fraction collector, while the absorbance is measured with a spectrophotometer or the like. In this way, the separated sample 90 is pushed from the outside into the interior of the separation chamber 24 by further flow of the extrusion fluid, and the separated sample 90 is collected through the central axis hole 45, as shown by arrows 93a and 93b. The above series of steps is carried out in a condition in which the rotor chamber 4 and the atmosphere are sealed.

[0039] As described above, in this embodiment, in addition to the fluid supply groove 52, the stress relief groove 57 is formed in the upper surface of the rotor core 40. This reduces the deformation of the rotor core 40 during high-speed rotation, thereby decreasing the risk of breakage during repeated use and significantly extending the service life of the rotor core 40.

[0040] Next, a variation example of the load release groove 57 of the embodiment is presented with reference to the Fig. 9 to 11 described. As in Fig. As described in Figure 5(C), the stress relief groove 57 is designed to counteract the bending moment caused by the fluid supply groove 52. Therefore, the stress relief groove 57 can be formed in various positions with respect to its shape and arrangement, and its shape can differ as long as the effect is sufficient. Fig. Figure 9(A) shows the shape of the load-release groove 57 of the embodiment, and the load-release groove 57 is designed such that it extends from the vicinity of a connecting section between the solid section 41 and the disk section 44 to the outer edge section. At this point, the right-hand part shows the variation in the cross-sectional shape of the fluid supply groove 52 and the load-release groove. The uppermost side view shows the [unclear] in the Fig. The cross-sectional shape of the load release groove 57 described in sections 3 to 8 is shown. Furthermore, the cross-sectional openings of the liquid supply groove 52 and the load release groove 57, located on the right side of the Fig. The 9 shown are rectangular, but actually the corners in the grooves can be rounded, as in Fig. 5(A) shown. With regard to the one on the upper right side of Fig. 9(A) The side surface shape shown is the width (length in circumferential direction) of the liquid supply groove 52 the same as that of the load release groove 57.

[0041] In the middle of the right side of Fig. In the side surface shape shown in 9(A), the width of the load release groove 77a is approximately 50% smaller than the width of the fluid supply groove 52. In the Fig. In the side surface shape shown in Figure 9(A) at the bottom right, the width of the load relief groove 77b is approximately 50% larger than the width of the fluid supply groove 52. In this way, the shapes of the load relief groove 57, 77a and 77b can be changed as long as the load reduction effect can be achieved.

[0042] In Fig. 9(B) the radial lengths of the load relief grooves 77 (77c to 77e) are the same as those of the load relief grooves 57, 77a and 77b in Fig. 9(A), and the stress relief grooves 77 are shaped such that they have a side face and cross-section in the form of an arc instead of a substantially rectangular shape. Three shapes of the stress relief grooves 77c to 77e are shown on the right side of Fig. 9(B) is shown. However, even if the cross-sectional shape of the load relief grooves 77c to 77e is curved orthogonally to the longitudinal direction, the load reduction effect can be achieved.

[0043] Fig. Figure 9(C) shows that the radial length of one load release groove 78 is shorter than that of the load release groove 78 of Fig. 9(B). At this point, the inner position indicated by arrow 78a is shifted outwards without changing the radial outer position of the load release groove 78. As shown on the right side of Fig. As shown in 9(C), the cross-sectional shape of the load release groove 78 is arc-shaped and orthogonal to the longitudinal direction, but the one in Fig. 9(A) and Fig. The forms shown in 9(B) can also be assumed.

[0044] Fig. Figure 10(A) shows that the position of a stress relief groove 79 on the outer side does not extend radially to the position at the outer edge of the disk section 44, but is located slightly inside the outer edge, as indicated by arrow 79b. As shown by arrow 79a, the position of the stress relief groove 79 on the inner circumferential side is the same as that of the stress relief groove 57, which is located in the Fig. 3 to 5 are shown here. Here, as on the right side of Fig. As shown in Figure 10(A), the cross-sectional shape of the load release groove 79 in a CC cross-section is arc-shaped, but various cross-sectional shapes are possible, as shown in the Fig. 8 and Fig. The 9 shown can also be assumed.

[0045] Fig. 10(B) shows that two in Fig. The stress relief grooves 79 shown in Figure 10(A) are arranged at intervals such that they lie next to each other in the circumferential direction. The position of each of the stress relief grooves 79A and 79B on the inner circumferential side is almost the same as that of the grooves shown in the Fig. 3 to 5 shown load release groove 57, and the position of each of the load release grooves 79A and 79B on the outer circumferential side is almost the same as that of the in Fig. 10(A) shown load relief groove 79. As the two cross-sectional shapes of a DD section on the right show, the cross-sectional shapes of the load relief grooves 79A and 79B can be an arc shape or an essentially rectangular shape like the load relief grooves 79C and 79D.

[0046] Fig. Figure 11 shows another example of a stress relief groove. Fig. In 11(A), three hemispherical recesses 157A to 157C are formed instead of the groove. As shown on the right side of Fig. As shown in Figure 11(A), the cross-sectional shape of the recess 157C in an EE cross-section is semicircular. The positions at which these recesses 157A to 157C are formed are arranged such that they completely or partially overlap the liquid supply groove 52 when viewed in the direction of axis A1.

[0047] In Fig. 11(A) Several stress relief grooves are designed to be intermittent in the radial direction, but in Fig. 11(B) The stress relief groove is designed such that its width (length in the circumferential direction) changes according to the radial position. That is, when the disk section 44 is viewed from the underside, a stress relief groove 158 is formed in a triangular, wedge-shaped form. The cross-sectional shape in an FF cross-section is as shown on the right side of Fig. 11(B) shown. In addition, the cross-sectional shape of the load relief groove 158 can be arc-shaped, with the corners being formed by a smooth, curved surface instead of being formed in an essentially rectangular shape with corners.

[0048] The rotor core 40 of the embodiment and various variations of the stress relief groove have been described above, but the shape of the rotor core 40 is not limited to the shapes in the embodiment described above, and the same effect as in the embodiment can be achieved as long as the rotor core 40 has a type of recess formed on the lower surface of the disk section 44. Furthermore, the rotor core 40 can be made of metal instead of synthetic resin material. [List of reference symbols] 1 centrifuge 2 cases 3 bowls 4 Rotor space 8 Protector 9 engine 10 rotating shaft 11 wreath 12 dampers 13 Dividing plate 14 Cooling device 15 Control unit 16 foot element 18 Door 18a Through hole 20 Rotor 21 rotor bodies 22 Exclusion 23 lead 24 Separation chamber 25 holes for the rotating shaft 27 O-ring 28 sealing packs 30 Cover 30a Through hole 31 disc area 32 cylindrical surface 34 Inverted funnel-shaped flow path section 35 wave Room 36 37 Exclusion 40 core 41 massive section 42 step ratio 42a Exclusion 43 lead 44 disc section 45 central axle hole 45a upper opening 46 radial holes 46a Opening 47 L-shaped opening 47a Opening 47c upper opening 49 holes 50 Liquid supply groove 51 Liquid supply groove 52 Fluid supply groove 56 in-depth section 57 Load relief groove 58 shovel blade 70 door adapters 71 Sealing housing 72 Sample inlet / outlet 73 Density gradient fluid inlet 74 Water outlet 77, 77a to 77c Load relief groove 78, 79, 79A, 79B Load relief groove 90 separated samples 140 core 141 Fixed Section 143 lead 144 disc section 144a upper surface 144b lower surface 146 Radial Hole 147 L-shaped hole 152 Liquid supply groove 158 Load relief groove 160 titanium sleeve A1 axis of rotation

Claims

[1] Rotor (20) for a centrifuge (1), which is set in rotation by a drive source (9), comprising: a rotor body (21) in which a recess (22) is formed; a rotor core (40) which is arranged in the recess (22); and a rotor cover (30) for closing an opening of the rotor body (21), characterized by , that the rotor core (40) has the following features: a column-shaped solid section (41); a disc section (44) extending radially outwards from an upper surface of the solid section (41); a liquid supply groove (50) arranged on an upper surface of the rotor core (40) and extending continuously from the solid section (41) to the disk section; and a liquid supply opening designed to extend downwards from the upper surface of the solid section (41) and further in a radial direction, and a stress relief groove (57, 158) which is formed on a lower surface of the disc section (44). [2] Rotor (20) for a centrifuge (1) according to claim 1, wherein the rotor core (40) is a one-piece element made of resin or metal, an opening section of the liquid supply groove is closed by contact with an inner wall of the rotor cover (30) and when the disk section (44) is viewed in an axis direction, the stress relaxation groove (57, 158) is arranged at a position that partially overlaps with the position of the liquid supply groove (50). [3] Rotor (20) for a centrifuge (1) according to claim 2, wherein the load release groove (57, 158) is a groove extending radially from an inner circumferential side to an outer circumferential side on the lower surface of the disk section (44), and an end section on the outer circumferential side reaches an outer edge section of the disk section (44). [4] Rotor (20) for a centrifuge (1) according to claim 3, wherein a plurality of liquid feed grooves (50) are formed at equal intervals in the circumferential direction, and the load release groove (57, 158) is shaped to correspond to the plurality of liquid feed grooves (57, 158). [5] Rotor (20) for a centrifuge (1) according to claim 4, wherein the liquid feed groove (50) has a U-shaped cross-section orthogonal to the direction of extension, and the stress relaxation groove (57, 158) has a rectangular, U-shaped or V-shaped cross-section orthogonal to the direction of extension. [6] Rotor (20) for centrifuge (1) according to claim 5, wherein a depth D2 of the load release groove (57, 158) satisfies D1 + D2 < T, wherein a thickness of the disk section (44) is T and a depth of the liquid feed groove (50) is D1. [7] Rotor (20) for a centrifuge (1) according to claim 6, wherein a plurality of the load relief grooves (57, 158) are distributed in the circumferential direction or in the radial direction with respect to each of the liquid supply grooves (50). [8] Rotor (20) for a centrifuge (1) according to one of claims 1 to 7, wherein a blade (58) is further arranged extending radially outwards from an outer circumferential surface of the solid section (41), wherein the blade (58) has a vertical plate shape connected to the disk section (44), and the disk section (44), the solid section (41) and the blade (58) are formed in one piece. [9] Rotor (20) for a centrifuge (1) according to claim 8, wherein a column-shaped projection (143) extending axially upwards is formed in an axial center of the upper surface of the solid section (41), and the liquid feed groove (50) is formed from axial groove sections (51) extending downwards on an outer circumferential surface of the projection (143), and four radial groove sections (152) extending radially outwards from a lower end of the axial groove section (51) with respect to the solid section (41). [10] Rotor (20) for a centrifuge (1) according to claim 9, wherein the liquid inlet opening has the following: a first fluid supply opening (46, 146) having an upper opening in the axial center of an upper surface of the projection (143), extending downwards in the axial direction and outwards in the radial direction, and opening near the lower surface of the disk section (44) on the outer circumferential surface of the solid section (41); and a second liquid supply opening (47, 147) having an opening at a position next to the outside in the radial direction from the upper opening of the first liquid supply opening (46, 146), extending downwards in the axial direction and outwards in the center in the radial direction, and having an opening on the outer circumferential surface of the solid section (41). [11] Centrifuge (1) which has the following features: a rotor (20) for a centrifuge (1) according to one of claims 1 to 10; a door adapter which is mounted on the rotor cover (30) and has a through-hole through which a flow path runs, which directs a liquid into and out of the recess (22); a shell defining a rotor chamber (4) in which the rotor (20) for the centrifuge (1) rotates; and a housing (2) for receiving the drive source (9) and the shell (2).

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