JPH0619843U - Centrifuge rotor and bucket - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the generation of vortices and shorten the centrifugation time. [Structure] An outer shape of a vertical cross section passing through an axis of a horizontal disk-shaped rotor body is a streamline flowing from the axis in a radial direction or a shape close thereto. A plurality of rectangular bucket storage recesses are formed along the radius from the outer peripheral edge of the body. A fan-shaped rotor yoke that holds the bucket is formed between adjacent bucket storage recesses. When the bucket is swung up, the shape of its longitudinal cross-section is substantially the same as that of the rotor 2, and the bucket 3 is just fitted into the recess for storing the bucket to form a state in which one rotating disk is formed. As a result, eddies generated on the bottom surface side and the side surface side of the conventional bucket are suppressed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotor and a bucket of a centrifuge, and particularly to reduction of form resistance (wind loss).

[0002]

[Prior art]

 As shown in FIG. 4, the centrifuge 1 is equipped with a bucket 3 containing a sample tube or a tube rack containing sample tubes, which is mounted on a rotor 2 which is rotationally driven by a motor 1. In the figure, the bucket 3 is shown in a state of being swung up 90 degrees by receiving the centrifugal force due to the rotation. The rotor 2 is attached to the rotating shaft of the motor 1 by a nut 4. In the motor 1, a flange 6 integrally formed on the outer peripheral surface of the motor case is supported by a coil spring 8 mounted on the bottom surface of an outer box 7. A circular opening is provided on the upper surface 7a of the outer box 7, and the upper edge of the pan-shaped inner tank 9 is attached to the inner edge of the opening. A circular hole is provided at the center of the bottom surface of the inner tank 9, and the motor 1 projects into the inner tank 9 through the circular hole. A motor cover 10 made of rubber is hung on the protruding portion of the motor 1, and the rotary shaft of the motor protrudes from the hole of the cover.

A lid 12 is placed on the upper surface 7 a of the outer box, and an air suction hole 12 a is formed in the lid 12 on the extension line of the motor rotation shaft. When the rotor 2 rotates, the air on the central part of the rotor is blown to the outside, and the negative pressure is applied to that part. Therefore, the air is automatically sucked from the suction hole 12a, and the inner tank along the rotor 2 and the bucket 3 is sucked. 9 flows to the outside of the inner tank 9 through the exhaust hole 9a and is discharged to the outside of the outer box 7 through the sound deadening passage 13.

Since the rotor 2 and the bucket 3 are rotated at a high speed of, for example, 4000 rpm, heat is generated by friction with air, and the heat of the motor 1 is transferred to the rotor 2 through the rotating shaft, so that the rotor 2 has a considerably high temperature. become. Therefore, there is a risk that the sample will change its heat. Therefore, while the rotor is rotating, the outside air is automatically sucked in to cool the rotor 2, the bucket 3, the motor 1 and the like.

As shown in FIG. 5, in a conventional rotor 2, four arms 22 are integrally provided in a cross shape from an outer peripheral surface of a disk-shaped central portion 21, and each arm 22 has a Y shape in the middle. An engaging groove 24 for engaging the engaging pin 3a of the bucket 3 is formed in the branch portion 23 so as to be obliquely outward from the upper surface of the arm 22. The branch portions 23 of the adjacent arms 22 facing each other are substantially parallel to each other, and the bucket 3 is arranged between the branch portions 23.

As shown in FIG. 6A, the bucket 3 has a cylindrical shape that accommodates a sample tube 26 resembling a cylindrical bottle, and as shown in FIG. 6B, a plurality of test tube-shaped sample tubes (not shown). There is a rectangular parallelepiped shape that accommodates a rectangular tube rack 27 into which a square tube is inserted. On these peripheral surfaces, a pair of engaging pins 3a are provided which respectively project in the rotational direction of the rotor and in the opposite direction.

[0007]

[Problems to be solved by the device]

 Recently, there has been a new request from users to shorten the centrifugation time of blood, etc., and to cope with this, increase the rotation speed of the rotor to generate a larger centrifugal force and shorten the centrifugation time. An attempt was made to However, although the motor input was increased to increase the rotor rotation speed, the wind resistance increased and the rotation speed did not increase as expected, resulting in a slight reduction in separation time. As a result of investigating the cause of the increase in wind resistance, eddies 31 are generated in the vicinity of the side surface of the bucket 3 opposite to the rotor rotation direction as shown in FIG. 6C, and as shown in FIG. It was found that the eddy 32 generated in the pipe with the tank 9 was the main cause. The present invention has been made in view of such circumstances, and its purpose is to suppress eddies that occur during rotation as much as possible to reduce wind loss (shape resistance) and adapt to high-speed rotation. It is to provide a rotor and a bucket that contribute to shortening the centrifugation time.

[0008]

[Means for Solving the Problems]

 (1) In the rotor according to claim 1, the outer shape of the vertical cross section passing through the axis of the horizontal disk-shaped rotor body is a streamline flowing from the axis in the radial direction or a shape close thereto. Further, a plurality of rectangular (when viewed from above the body) bucket storage recesses are formed at equal angular intervals along the radius from the outer peripheral edge of the body, and the buckets are held between adjacent bucket storage recesses. A fan-shaped rotor yoke (as viewed from above the body) is formed.

(2) The invention of claim 2 is a bucket for a centrifuge mounted in the bucket storage recess of the rotor, wherein the outer shape of the bucket viewed from the upper opening side of the bucket is It has a rectangular shape with a thickness approximately equal to the vertical dimension of the outer shape of the recessed portion of the bucket housing seen from the side and a width slightly smaller than the lateral dimension, on both side surfaces of the bucket that are close to and opposite to the rotor yoke. An engaging portion for attaching to the rotor yoke is provided.

In a state where the bucket is mounted on the rotor and swung up by the rotation of the rotor, the outer shapes of the both side surfaces of the bucket are substantially the same as the outer shape of the side surfaces of the mating rotor yokes that are closely opposed to each other. At the same time, the bottom edge of the bucket when viewed from above the rotor is an arc having a radius of curvature substantially the same as the outer circumference of the rotor yoke.

[0011]

【Example】

 1 to 3, parts corresponding to those in FIGS. 4 to 6 are designated by the same reference numerals, and duplicate description will be omitted. The embodiment of FIG. 1 is a case where the rotor 2 is provided with an engagement groove 2c for holding the bucket 3, and the bucket 3 is provided with an engagement pin 3a which engages with the engagement groove 2c. 2 is a case in which the engagement pin 2a is provided on the bucket 2 and the engagement groove 3b is provided on the bucket 3.

In the rotor 2 of the present invention, the outer shape of the vertical cross section passing through the axis of the horizontal disk-shaped body 2'is a streamline flowing from the axis in the radial direction or a shape close thereto. A plurality (four in the figure) of rectangular (when viewed from above the body) bucket storage recesses 2b are formed at equal angular intervals along the radius from the outer peripheral edge of the body 2 '. As a result, a fan-shaped rotor yoke 2a for holding the bucket 3 (as viewed from above the body) is formed between the adjacent bucket storage recesses 2b.

An engagement portion (engagement groove 2c or engagement pin 2a) for holding the bucket 3 is provided at an end of the rotor yoke 2a on the bucket storage recess 2b side. When the engaging groove 2c is provided, it is desirable that the inlet of the groove be provided as close to the motor shaft as possible in order to reduce windage loss. The bucket 3 mounted in the bucket storage recess 2b has a thickness whose outer shape as viewed from the upper opening 3e side is approximately equal to the vertical dimension of the outer shape of the inner surface 2d of the bucket storage recess 2b as viewed from the side of the rotor 2. t and a width w which is slightly smaller than the lateral dimension thereof are rectangular. Engagement portions (engagement pins 3a or engagement grooves 3b) for attaching to the rotor yoke 2a are provided on both side surfaces 3f and 3g of the bucket 3 which are close to and face the rotor yoke 2a.

When the bucket 3 is mounted on the rotor 2 and is swung up by the rotation of the rotor 2, the outer shapes of both side surfaces 3 f and 3 g of the bucket 3 become the outer shapes of the side surfaces of the opposing rotor yoke 2 a that face each other. The bottom edge 3h of the bucket 3 as viewed from above the rotor 2 is an arc having a radius of curvature substantially equal to the radius R of the outer circumference of the rotor yoke 2a, while having a substantially equal streamline shape or a shape close thereto.

The streamline-shaped cross section of the rotor and bucket of the present invention may have a vertically asymmetrical shape as shown in (b) and (c) in addition to the shape of (a) shown in FIG. 3B.

[0016]

[Effect of device]

 As described above, the peripheral wall of the rotor 2 and the bottom of the bucket 3 have almost the same streamline, and when the bucket 3 is swung up, the shapes of the longitudinal sections of the rotor 2 and the bucket 3 are almost the same. Then, the bucket 3 is just fitted into the bucket storage recess 2b of the rotor, so that a single rotating disk is formed (FIG. 3A). As a result, the eddy 32 (FIG. 4) generated between the bottom surface of the bucket 3 and the inner tank 9 and the eddy 31 (FIG. 6C) generated on the peripheral surface of the bucket 3 opposite to the rotor rotation direction are eliminated. . Therefore, the windage loss is smaller than in the conventional case, the rotation speed is increased, and thus the centrifugation time can be shortened.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of the present invention, in which A is a rotor A
0B sectional view, B is a plan view of A, C, D and E are a plan view, a front view and a side view of the bucket, respectively.

FIG. 2 is a view showing another embodiment of the present invention, in which A is a sectional view of the rotor taken along the line A0B, B is a plan view of A, and C, D, and E are plan views, front views, and side views of the bucket, respectively.

FIG. 3A is a longitudinal sectional view showing an outline of a centrifuge using a rotor and a bucket of the present invention, and B is a view showing a modified streamline-shaped cross section of the rotor and the bucket of the present invention.

FIG. 4 is a vertical sectional view showing an outline of a conventional centrifugal separator using a rotor and a bucket.

FIG. 5 is a perspective view of a rotor equipped with a conventional bucket.

6A and 6B are perspective views of a conventional bucket, and C is a view showing the flow of air around the bucket of A during rotor rotation.

[Procedure amendment]

[Submission date] June 23, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

Claims (2)

[Scope of utility model registration request] 1. A horizontal disk-shaped rotor body has a vertical cross-section that passes through the axis of the body and has a streamline shape that flows in the direction of the radiation from the axis or a shape close to the streamline. Bucket accommodating recesses having a shape (as viewed from above the body) are formed at equiangular intervals, and fan-shaped (as viewed from above the body) rotor yokes for holding buckets are formed between adjacent bucket accommodating recesses. A rotor for a centrifuge. 2. A bucket for a centrifuge, which is mounted in the bucket storage recess of the rotor, wherein the outer shape of the bucket viewed from the upper opening side of the bucket is the bucket storage recess viewed from the side of the rotor. Thickness of the outer surface of the bucket is approximately equal to the vertical dimension, and a rectangular shape with a width that is slightly smaller than the lateral dimension of the outer surface of the bucket.
An engaging portion for attaching to the rotor yoke is provided, and in a state where the engaging portion is attached to the rotor and swung up by the rotation of the rotor, the outer shapes of the both side surfaces of the bucket are approximately the same as the outer shape of the side surface of the mating rotor yoke that is closely opposed. A bucket for a centrifuge characterized in that the bucket has an equal streamline shape or a shape close to it, and a bottom edge of the bucket viewed from above the rotor is an arc having a radius of curvature substantially the same as the outer circumference of the rotor yoke.