JP2010082514A - Rotor for centrifuge and centrifuge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor for centrifuge where long buckets are provided and the center of gravity is positioned at a low point, and a centrifuge. <P>SOLUTION: The rotor for centrifuge includes a hub 12 that is rotatably connected to a driving shaft, a plurality of arms 13 disposed around a rotary shaft O of the hub 12, and a plurality of buckets 14 that are each attached to a plurality of the arms 13 and are each same shapes, wherein each of the buckets 14 is slidably pin joined to each of the arms 13 at the same positions and in the same shapes, each arm 13 is configured by a pair of arm sections 13A, 13B that support pins by the buckets 14 interposed, and a central axis La running at a center of the arm sections 13A, 13B and extending on a plane which intersects with the rotary shaft O is configured to escape from the rotary shaft O, the axes Lb of pin joints are each disposed at an equal distance from the rotary shaft O, and orthogonally intersect with the rotary shaft O and with the central axis La. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a centrifuge rotor and a centrifuge, and more particularly to a centrifuge rotor and a centrifuge provided with a swinging bucket.

  A centrifuge that rotates at a maximum rotation speed of about 3,000 to 5,000 rpm is used for the purpose of examining blood, urine, etc., and generally uses a swing rotor that houses a sample container in a rotatable bucket. Is.

  The swing rotor includes a hub extending coaxially with a drive shaft protruding into the centrifuge chamber of the centrifuge, and a plurality of arm portions extending radially outward from the hub. The arm portion is provided with a plurality of pairs each having a pair of arms facing each other, and each pair of arms rotatably supports a bucket holding a sample container. Specifically, each of the pair of arms is provided with a pair of holding pins, and the bucket is formed with a pin receiving portion that is rotatably supported by the holding pins.

  When the swing rotor rotates, the bucket supported by the arm swings horizontally around the pair of holding pins in the centrifuge chamber, and the sample in the sample container is centrifuged. In order to perform centrifugation here, the position and length of the arm part, the position of the pin in each arm that receives the pin holding part of the bucket, the length of the bucket itself, the length of the sample container held in the bucket, Due to the relationship between the inner diameter and height of the centrifuge chamber, there are dimensional constraints.

  For example, the length of the arm portion and the position of the pin receiving portion should be set as radially outward as possible so as to ensure the maximum centrifugal radius when the bucket swings in the horizontal direction. It is a condition that the bottom of this does not contact | abut to the internal peripheral surface of a centrifuge chamber. If the length of the sample container itself is too long, the tip of the sample container (the opening where the sample is inserted / discharged) contacts the upper surface of the rotor hub when the bucket or sample container swings horizontally during centrifugation. It is necessary to avoid this because it may damage the sample container due to interference.

In order to solve the above problems, Patent Document 1 discloses a configuration that prevents the tip of the sample container from interfering with the upper surface of the hub during centrifugation even when a long bucket is used. In this configuration, the free end side of each arm protrudes upward, and the pin receiving portion is formed in the protruding portion of each arm, and the position of the pin receiving portion is set higher than the upper surface of the hub. By attaching the bucket to this pin bearing, when the bucket is rotated horizontally between the pair of arms, the tip side of the sample container accommodated in the bucket can be disposed above the upper surface of the hub. Interference can be avoided.
JP-T 61-502314

  However, in the centrifuge and the centrifuge rotor shown in Patent Document 1, the position of the pin receiving portion is high, and the center of gravity of the entire rotor is at the top of the rotor, so that the stability during rotation is poor. There is. Therefore, an object of the present invention is to provide a centrifuge rotor and a centrifuge that have long buckets and that have a low center of gravity to ensure rotational stability.

  In order to solve the above-described problems, the present invention provides a hub connected to a drive shaft portion and rotatable, a plurality of arms arranged around the rotation axis of the hub, and a plurality of arms respectively attached to the plurality of arms. And each of the buckets is pivotably connected to each of the arms, and each of the arms includes a pair of arms that pin-support the bucket therebetween. The centrifuge rotor is configured such that a central axis passing through the center between the pair of arm portions deviates from the rotation axis.

  In the centrifuge rotor having the above-described configuration, each of the arms and each of the buckets is preferably configured such that each pin joint axis is disposed at an equal distance from the rotation shaft.

  According to such a configuration, in the state where the rotor is rotated and the bucket is swung in the horizontal direction, the axis of the bucket orthogonal to the pin joint axis is substantially coincident with the central axis of the arm portion. It does not coincide with the radial axis centered on the rotation axis. Therefore, in a state where the bucket swings and is in the horizontal direction, the sum of the distance from the hub central axis to the pin joint position and the distance from the pin joint position to the outer peripheral end of the bucket is from the hub rotation axis. A value larger than the distance (rotation radius) from the pin joint position to the outermost peripheral position can be set. That is, when a bucket having the same shape is used as compared with a conventional centrifuge rotor in which the axial direction of the bucket coincides with the radially extending axis when using buckets having the same length, the present invention The centrifuge rotor can reduce the distance (rotation radius) from the rotation axis to the outermost peripheral position. Therefore, even when a long bucket is used, an increase in the distance (radius) from the rotating shaft of the centrifuge rotor to the outermost peripheral position can be suppressed. In addition, since a long bucket can be mounted as described above, by setting the bucket length to a suitable value, an end portion that becomes an anti-peripheral position of the bucket in a state where the bucket swings and is in a horizontal direction; Interference with the hub around the rotating shaft is suppressed. Therefore, it is not necessary to prevent the interference between the pin joint position above the upper surface of the hub and the end portion of the bucket that is opposite to the outer peripheral position of the bucket and the hub, and the high center of gravity of the centrifuge rotor can be suppressed.

  Moreover, the distance between one adjacent arm and another arm among several arms can be taken large. Therefore, by increasing the distance between one adjacent arm and the other arm, the cross-sectional area of the portion connected to the hub of the arm can be increased. Centrifugal force is also applied to each arm by the rotation of the centrifuge rotor, but the strength of the arm against the centrifugal force can be increased by taking a large cross-sectional area as described above, so that the centrifuge can withstand higher speed rotation. A machine rotor can be provided. Further, if the above-described cross-sectional area is not increased, the space between the pair of arm portions can be increased and the space between the pair of arm portions up to a position near the center axis of the hub. A longer bucket can be held without changing its turning radius.

  In order to solve the above-described problems, the present invention defines any one of the above-described centrifuge rotors, a drive unit that drives the centrifuge rotors, and a rotor chamber that houses the centrifuge rotors. There is provided a centrifuge comprising: a rotor chamber defining section formed; and a door placed on the rotor chamber defining section for closing and releasing the rotor chamber.

  According to the centrifuge rotor and the centrifuge of the present invention, the rotational stability can be ensured by setting the center of gravity to a low position.

  Hereinafter, a rotor for a centrifuge and a centrifuge according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5. A centrifuge 1 shown in FIG. 1 mainly includes a frame 2, a motor 3, a chamber part 4, a door 5, and a rotor part 10. The frame 2 forms a skeleton of the centrifuge 1 and is covered with a housing 21 to form an outline of the centrifuge 1. A control device (not shown) for driving and controlling the motor 3 and the like is disposed in the housing 21.

  The motor 3 has a shaft case 3A, and a drive shaft (not shown) is disposed in the shaft case 3A. A coupling part 3B called a crown for engaging with the rotor is provided at one end of the drive shaft on the side opposite to the motor. It is fixed to the frame 2 by a motor support portion 31 made of vibration-proof rubber or the like that absorbs vibration or the like, and the shaft case 3A is disposed so as to protrude into a rotor chamber 4a described later.

  The chamber portion 4 is provided on the frame 2 and includes a metal plate 4A that forms an upper chamber that opens upward and incorporates the rotor portion 10, and a heat insulating material 4B that is disposed around the metal plate 4A. It is configured. Further, in the chamber portion 4, an opening 4 b from which the shaft case 3 </ b> A of the motor 3 protrudes is formed in a portion that becomes the bottom wall of the rotor chamber 4 a. The opening 4b from which the shaft case 3A protrudes in the chamber 4 is attached with a cover 4C to close the opening 4b.

  The door 5 is hinged on the chamber portion 4 so as to be opened and closed, and is configured to close and seal the rotor chamber 4a and to keep the rotor chamber 4a open so that the rotor portion 10 can be attached and detached. . A lock mechanism 5 </ b> A that holds the door 5 in a closed state is provided at a portion of the door 5 that is positioned on the chamber portion 4 in a closed state. Locking the lock mechanism 5A prevents the door 5 from being opened while the rotor unit 10 is rotating.

  The rotor portion 10 is configured to be fixed so as to rotate coaxially and integrally with the shaft case 3 </ b> A, and mainly includes a swing rotor body 11 and a bucket 14. As shown in FIG. 2, the swing rotor body 11 is composed of a hub 12 and four arm portions 13 that are equally arranged on four sides of the hub 12. As shown in FIG. 1, the hub 12 is formed in a columnar shape and is a place connected to the coupling portion 3B. The four arm portions 13 are arranged at intervals of 90 ° around the rotation axis O of the hub 12 and are configured in a point-symmetric shape with the rotation axis O as the center of the object. Therefore, only one arm portion 13 of the four arm portions 13 will be described unless otherwise specified. The arm portion 13 connects between a pair of the first arm portion 13A and the second arm portion 13B extending in parallel with each other on a plane orthogonal to the rotation axis O, and the first arm portion 13A and the second arm portion 13B. It is mainly composed of the wall 13E. The first arm portion 13A and the second arm portion 13B are configured such that a central axis La passing through the center between the first arm portion 13A and the second arm portion 13B deviates from the rotation axis O. That is, the central axis La extends parallel to the axis extending through the rotation axis O in the radial direction with a certain distance L1.

  By adopting such a configuration, one arm portion 13 (for example, the arm portion 13 in FIG. 2A) and another adjacent arm portion 13 (for example, the arm portion 13 in FIG. 2B) are provided. The distance between can be increased. Specifically, the first arm portion 13A of one arm portion 13 and the second arm portion 13B of another arm portion 13 adjacent to the first arm portion 13A of one arm portion 13 are connected from the hub 12. The width in the direction intersecting with the radial direction of the extended region S can be increased. Further, the first arm portion 13A of one arm portion 13 and the second arm portion 13B of another arm portion 13 adjacent to the first arm portion 13A of one arm portion 13 are one from the rotation axis O. The region S is configured to be positioned on a straight line connecting the center of gravity Ca of the first arm portion 13A of the arm portion 13 and the second arm portion 13B of the other arm portion 13. When the swing rotor body 11 is rotated, a centrifugal force is generated in the first arm portion 13A of one arm portion 13 and the second arm portion 13B of the other arm portion 13, but the centrifugal load is the center of gravity Ca. Since it acts on a straight line connecting the rotation axis O, the centrifugal load due to the centrifugal force is borne in the region S. Therefore, by increasing the width of the region S, the cross-sectional area of the cross section that intersects the radial direction in the region S increases, and the stress per unit area in the cross section that intersects the radial direction of the region S can be reduced. Therefore, the strength against the centrifugal force in the region S can be increased, and higher speed rotation can be handled.

  In addition, the width of the region S only needs to withstand the centrifugal force generated at a predetermined number of revolutions (in the present embodiment, about 3,000 to 5,000 rpm). There should be a minimum width. When the width of the region S is set to the minimum necessary, a large space between the pair of first arm portions 13A and the second arm portions 13B can be taken. Specifically, the wall portion 13E is brought close to the position near the hub 12, and the extension amount of the pair of first arm portions 13A and the second arm portion 13B extending from the wall portion 13E is increased, thereby the pair of first arm portions. The space between 13A and the 2nd arm part 13B is enlarged.

  In the arm portion 13, a holding pin 13 </ b> C and a holding pin 13 </ b> D having a circular cross section protrude from positions facing each other on the mutually facing surfaces of the first arm portion 13 </ b> A and the second arm portion 13 </ b> B. The holding pins 13C and 13D are arranged such that the pin axis Lb from the one holding pin 13C to the other holding pin 13D is orthogonal to the central axis La. The rotation axis O and the pin axis Lb do not directly intersect, but are at right angles when viewed from the direction of the arrow V in FIG. Further, in the arm portion 13, the holding pins 13C and 13D are such that the distance L2 from the pin shaft Lb position of the holding pins 13C and 13D position to the wall portion 13E is from the position of locking portions 14a and 14b in the bucket 14 to be described later to the uppermost portion of the bucket 14. It is arrange | positioned in the position which becomes larger than the distance L3. As described above, since the wall portion 13E is close to the hub 12, the distance L2 from the pin shaft Lb position of the holding pins 13C and 13D to the wall portion 13E can be increased.

  Further, by shifting the center axis La, a predetermined width is secured in the region S. If the predetermined width is secured, the space between the first arm portion 13A and the second arm portion 13B is expanded. May be.

  An example of the bucket 14 is shown in FIG. A substantially cylindrical bucket body 14A with one end closed, a cap 14B for closing the other end opening of the bucket body 14A, and a sample container 14C containing a sample to be inserted into the bucket body 14A from the other end opening and separated. It is mainly composed. Locking portions 14a and 14b with which the holding pin 13C and the holding pin 13D (FIG. 2) engage are formed on both side portions of the bucket body 14A. As shown in FIG. 4, the locking portion 14a is formed so that the inner peripheral surface has a substantially U shape, and the locking portion 14b is formed in the same manner. Therefore, by inserting the holding pins 13C and 13D into the locking portions 14a and 14b, the bucket 14 is pin-joined to the arm portion 13 (FIG. 2), and the bucket 14 swings with the pin shaft Lb as the swinging axis. Can move. The distance L3 from the swing center position of the locking portions 14a and 14b, which is the pin joint position, to the end portion (upper end portion) of the bucket 14 on the cap 14B side is from the position of the holding pins 13C and 13D to the wall portion 13E. It is configured to be slightly smaller than the distance L2. Further, the distance from the positions of the locking portions 14a and 14b, which are pin joint positions, to the end (lower end) of the bucket 14 on the side opposite to the cap 14B is defined as L4.

  In the bucket 14, the diameter of the cap 14 </ b> B and the diameter of the position where the locking portions 14 a and 14 b of the bucket body 14 </ b> A are formed are slightly smaller than the distance from the first arm portion 13 </ b> A to the second arm portion 13 </ b> B. It is configured. Therefore, in a state in which the bucket 14 is disposed between the first arm portion 13A and the second arm portion 13B and pin-joined, the central axis Lc of the bucket 14 is always perpendicular to the pin axis Lb, and its swinging Is coincident with a plane orthogonal to the pin axis Lb. Further, the position of the center of gravity Cb of the bucket 14 is substantially the center position in the vertical direction and the width direction, as shown in FIGS.

  When the bucket 14 is attached to the swing rotor body 11, the lower end of the bucket 14 is suspended from the positions of the holding pins 13C and 13D (FIG. 2) as shown in FIG. 1 when the rotor portion 10 is not rotating. It is arranged in the state that was done.

  When the rotor unit 10 is rotated from this state, the bucket 14 swings about the pin shaft Lb, and the longitudinal direction coincides with the horizontal direction as shown in FIG. In this state, the central axis Lc that passes through the center of gravity Cb of the bucket 14 and is orthogonal to the pin axis Lb coincides with the central axis La, and therefore coincides with an axis extending radially from the rotational axis O of the hub 12. There is no. Therefore, the sum of the distance L5 from the rotation axis O to the pin joint position P1 and the distance L4 from the pin joint position P1 to the outer end (lower end) P2 of the bucket 14 with the bucket 14 in the horizontal direction. (L5 + L4) can be set to a value larger than the rotation radius L6 of the rotor portion 10 which is the distance from the rotation axis O to the pin outer peripheral position P2 to the outermost peripheral position P2 (L5 + L4> L6). Therefore, the distance L4 from the pin joint position to the outer peripheral end of the bucket 14 can be made larger than the value obtained by subtracting the distance L5 from the rotational radius L6 to the rotational axis O to the pin joint position (L4> L6-L5). ).

  In the conventional centrifuge, since the axial direction of the bucket coincides with the axis extending in the radial direction, the sum of the distance L4 ′ (corresponding to the distance L4) and the distance L5 ′ (corresponding to the distance L5) in the conventional centrifuge is conventional. Is equal to the rotation radius L6 ′ (corresponding to the rotation radius L6), and therefore the distance L4 ′ in the conventional centrifuge is equal to the value obtained by dividing the rotation radius L6 ′ by the distance L5 ′ (L4 ′ = L6′−L5). '). Therefore, when the rotation radius L6 = the rotation radius L6 ′ and the distance L5 = the distance L5 ′, the distance L4> the distance L4 ′, and the distance L4 from the pin joint position to the lower end portion of the bucket 14 in this embodiment The distance can be larger than the distance L4 ′ from the pin joint position in the centrifuge to the lower end of the bucket.

  As described above, in the swing rotor body 11, the distance L2 from the holding pins 13C and 13D positions to the wall portion 13E can be increased, and therefore the distance L3 from the pin joint position to the upper end portion of the bucket 14 is increased. Can do. In addition, since the distance L4 from the pin joint position to the lower end of the bucket 14 can be increased, a longer bucket 14 than the conventional one is mounted on the rotor unit 10 having the same radius of rotation L6 as that of the conventional centrifuge. It is possible to suppress the increase in the rotation radius L6.

  As described above, since the long bucket 14 can be mounted, by setting the length of the bucket 14 to a suitable value, the upper end of the bucket 14 and the rotating shaft can be rotated in a state where the bucket 14 swings horizontally. Interference with the hub 12 around O is suppressed. Therefore, it is not necessary to adopt a configuration for preventing interference between the bucket 14 and the hub 12 such as letting the pin joint position escape above the upper surface of the hub, and the high center of gravity of the rotor portion 10 can be suppressed.

The side sectional view of the centrifuge concerning an embodiment of the invention. The top view of the swing rotor in the rotor of the centrifuge concerning embodiment of this invention. Side surface sectional drawing of the bucket in the rotor of the centrifuge concerning embodiment of this invention. The front view of the bucket in the rotor of the centrifuge concerning embodiment of this invention. The top view in the rotation state of the rotor of the centrifuge concerning embodiment of this invention.

Explanation of symbols

1. Centrifuge 2. Frame 3. Motor 3A Shaft case 3B Coupling part 4. Chamber part 4A Metal plate 4B Heat insulation 4C Cover 4a Rotor room 4b ..Opening part 5 ..Door 5A ..Lock mechanism 10 ..Rotor part 11 ..Swing rotor body 12 ..Hub 13 ..Arm part 13A ..First arm part 13B ..Second arm part 13C. Holding pin 13D ... Holding pin 13E ... Wall 14 ... Bucket 14A ... Bucket body 14B ... Cap 14C ... Sample container 14a ... Locking portion 14b ... Locking portion 21 ... Housing 31 ... Motor Support part

Claims (3)

A rotatable hub connected to the drive shaft,
A plurality of arms arranged around a rotation axis of the hub;
A plurality of buckets respectively attached to the plurality of arms,
Each of the buckets is swingably pinned to each of the arms,
Each of the arms is configured to include a pair of arm portions that pin-support the bucket therebetween, and a center axis that passes through the center between the pair of arm portions is configured to deviate from the rotation axis. A rotor for a centrifuge characterized by that.   2. The centrifuge according to claim 1, wherein each of the arms and each of the buckets is configured such that an axis of each of the pin joints is arranged at an equal distance from the rotation shaft. Rotor. The centrifuge rotor according to claim 1 or 2,
A drive unit for driving the centrifuge rotor;
A rotor chamber defining section that defines a rotor chamber that houses the rotor for the centrifuge;
A centrifuge comprising: a door placed on the rotor chamber defining portion and closing and releasing the rotor chamber.

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