JP2002316070A - Swing rotor for centrifugal separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swing rotor for a centrifugal separator, in which a bucket is prevented from being reversed and dropping out by a comparative simple structure. SOLUTION: A bucket housing part 24 for housing the bucket 22 is prepared on a bucket holding member 21. The bucket 22 is supported to be rotated freely by projecting trunnion pins 26 onto the side walls 25a, 25b of the part 24. A long groove 47 long in the axial direction to which each of the pins 26 is engaged and inserted is formed on each of both side faces of the bucket 22. The rotational angle of the bucket 22 is controlled by arranging rotation controlling parts 52 on both side walls 25a, 25b of the part 24 so that the bucket 22 is prevented from being reversed and dropping out of the pins 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal swing rotor for separating a liquid sample such as blood using centrifugal force, and in particular, to prevent a bucket from inverting, falling off a support shaft and dropping. And a swing rotor for a centrifuge as described above.

[0002]

2. Description of the Related Art In general, small centrifuges widely used in hospitals, research laboratories, and the like, transmit the rotation of a drive motor directly to the rotor and rotate the rotor at high speed, thereby utilizing the liquid by centrifugal force. The sample is separated according to the difference in density.

[0003] By the way, as a rotor for a centrifuge,
Broadly, there are two types of rotors called "angle rotors" and "swing rotors". The angle rotor forms a main stream of the rotor, and holds a sample container (tube) containing a sample to be centrifuged at a required angle (for example, 45 °) with respect to the rotation axis of the rotor. A tube holding hole is provided. In a swing rotor, a tube is housed in a bucket, the bucket is rotatably supported by a support shaft (trunnion pin) of the rotor, and the bucket is swung up (swings) by centrifugal force. As the swing rotor, there are two types, a bucket in which a tube containing a liquid sample is loaded is provided so as not to be detachable from the swing rotor body, and a bucket in which a bucket is detachably attached to the swing rotor body. The present invention relates to the latter type of centrifuge swing rotor.

[0004] In the case of a swing rotor having a structure in which the bucket cannot be removed from the swing rotor body, the user can only perform centrifugal separation with a tube having a size that fits into the attached bucket, which is inconvenient. . When loading tubes of different sizes (small), an adapter is used, but there is a disadvantage that the number of tubes is limited. However, there is an advantage that the bucket is not erroneously hooked due to the attachment / detachment of the bucket.

On the other hand, in a swing rotor having a structure in which a bucket can be detached from a swing rotor body, several types of buckets having dimensions suitable for the tube are prepared according to the size of the tube. You can select and use buckets for
It is more versatile than a swing rotor whose bucket cannot be removed.

[0006]

As described above, in a swing rotor having a structure in which a bucket can be removed from a swing rotor body, various tubes having different dimensions can be used by replacing the bucket. However, the mounting structure of the bucket with respect to the swing rotor body usually has a long groove formed on both sides of the bucket in the axial direction, a bucket storage portion for storing the bucket on the swing rotor body side, and a support shaft (trunnion) in the bucket storage portion. pin)
Are provided corresponding to the long grooves, and the bucket is dropped from above into the bucket storage portion and is rotatably supported by trunnion pins. For this reason, when the operator mistakenly rotates the bucket after mounting the bucket in the bucket storage unit, there is a problem that the bucket is turned upside down and used in a state of dropping from the trunnion pin. For this reason, before using the centrifuge, it is necessary to check whether or not the bucket has fallen off. However, the fact is that the operator has not always sufficiently checked.

The following case is considered as an example in which the operator neglected to confirm the dropout. In other words, a plurality of (usually four) buckets are mounted on the swing rotor, but if the number of tubes is such that all the buckets are used, when the tubes are inserted into the insertion holes of the buckets. Since the user always notices that the bucket has been turned upside down and has fallen, the bucket can be returned to a normal state if it has fallen. However, when the number of tubes to be centrifuged is small, especially when there are only two tubes,
The user usually selects two buckets facing each other,
Since each of them is loaded with one tube (so as not to become unbalanced when rotating), the two buckets for loading tubes are noticed as to whether or not they have fallen off, but the tubes are not loaded. Attention may not be paid to the remaining buckets, and the user may not notice that the buckets have been turned upside down and fall off. When the swing rotor is rotated at high speed and centrifugal separation is performed in a state of being dropped, the falling bucket moves radially outward of the swing rotor due to centrifugal force, and the outer peripheral wall of the swing rotor ( The windshield).

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to make it possible to reliably prevent the bucket from being turned over and dropped with a relatively simple structure. An object of the present invention is to provide a swing rotor for a centrifuge.

[0009]

According to a first aspect of the present invention, there is provided a windshield case having a bottomed cylindrical shape opened upward, a bucket holding member provided in the windshield case, and A plurality of buckets detachably and rotatably locked to a bucket holding member, wherein the swing rotor for a centrifugal separator attached to the drive shaft of the drive motor is open to lower ends on both side surfaces of the bucket. A long groove in the axial direction is provided, a plurality of bucket storage portions are radially provided at equal intervals in the circumferential direction on the bucket holding member, and a pair of supports engaged with the long grooves are provided on a side wall of each bucket storage portion. A shaft and a rotation restricting portion for restricting a rotation angle of the bucket are provided. In the present invention, the support shaft rotatably supports the bucket. Since the rotation of the bucket is restricted within a certain angle by the rotation restricting portion, the bucket does not reverse, and is prevented from falling off from the support shaft.

[0010] The second invention is the above-mentioned first invention, wherein:
The rotation restricting portion is integrally provided on a side wall of the bucket storage portion. In the present invention, since the rotation restricting portion is provided integrally with the bucket holding member, a separate rotation restricting member is not required.

According to a third aspect, in the first aspect,
The rotation restricting portion is a protrusion protruding from a side wall of the bucket storage portion. In the present invention, the protrusion regulates rotation of the bucket. The head may be a screw head, a pin-shaped member, or the like.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is a cross-sectional view showing an embodiment of a centrifuge provided with a swing rotor according to the present invention, FIG. 2 is a plan view showing a part of the swing rotor when it is not used, and FIG. FIG. 4 is an enlarged sectional view taken along line III-III of FIG. 4, FIG. 4 is a plan view showing a part of the swing rotor in a centrifugal processing state, and FIG. 5 is an enlarged sectional view taken along line VV of FIG.

In FIG. 1, a centrifugal separator generally indicated by reference numeral 1 includes a drive motor 3 elastically supported in a housing 2, a swing rotor 5 detachably mounted on a drive shaft 4 of the drive motor 3, and the like. It is composed of

The drive motor 3 is a conventional well-known induction motor or synchronous motor. A flange 7 of a housing 6 for accommodating a stator, a rotor and the like (not shown) is provided with a horizontal motor mounting plate 8 provided in the housing 2. Are elastically fixed by a plurality of bolts 9 and nuts 10 through a vibration isolating material 11 such as a rubber isolating rubber.

The drive shaft 4 has an upper end formed in the housing 6.
The swing rotor 5 is fixed to the upper end of the swing rotor 5 by mounting bolts 12, and rotation is transmitted to the swing rotor 5 by a plurality of drive pins 13. The mounting bolt 12 is screwed into a screw hole 14 provided on the upper surface of the drive shaft 4 via a flat washer 15 and a spring washer 16. The flat washer 15 presses the swing rotor 5 to prevent the swing rotor 5 from slipping upward. I have. The drive pin 13 is provided so as to protrude from the upper surface of a ring-shaped swing rotor holding bracket 17 fixed to the projecting end of the drive shaft 4 by welding or the like so as to be located on the same circumference.

The swing rotor 5 includes a windshield case 20
And a bucket holding member 2 disposed in the windshield case.
1 and four buckets 22 and the like which are detachably and rotatably attached to the bucket holding member 21. In FIG. 1, the right bucket 22 shows a state where the swing rotor 5 is not rotating, and the left bucket 22 shows a state where the swing rotor 5 is rotating at high speed.

The windshield case 20 is formed in a cylindrical shape with a bottom opening upward by an aluminum alloy or the like, so that a cylindrical windshield 20A and a disk closing the lower end side opening of the windshield 20A are formed. The bottom plate 20B is formed with a fitting hole 23 which is sufficiently larger than the outer diameter of the upper end of the drive shaft 4 at the center of the bottom plate 20B. Case 2
The depth of 0 is set sufficiently larger than the height of the bucket 22.

In FIG. 1 to FIG. 5, the bucket holding member 21 is made of a molded product made of an aluminum alloy integrally formed by die casting, and has four radially formed radially spaced at equal intervals in the circumferential direction. Bucket storage unit 24
have. The bucket accommodating portion 24 is formed of a substantially rectangular concave portion which is long in the radial direction and is open to the upper and lower surfaces and the outer peripheral surface of the bucket holding member 21. The bucket 22 is rotatably supported by two opposing side walls 25a and 25b. Supporting shafts (trunnion pins) 26 are respectively provided so as to be aligned with their axes.

Further, the structure of the bucket holding member 21 will be described in detail.
Cylindrical boss 21A having a through-hole 28 (FIG. 1) through which the upper end of the boss 21A penetrates, and four arms 21B integrally extending radially outward from each corner of the boss 21A.
It is composed of At the center of the lower end of the boss portion 21A, a small-diameter cylindrical portion 30 penetrating through the fitting hole 23 of the windshield case 20 is integrally provided. This small-diameter cylindrical portion 30
Has a pin fitting hole 31 in which the drive pin 13 is fitted on the lower surface, and presses the flat washer 15 against the upper surface of the boss portion 21A by fastening the mounting bolt 12 so that the upper surface of the swing rotor holding bracket 17 is formed. It is pressed.

In FIG. 2, the arm 21B has a first arm 21B ₁ extending in a diagonal direction of the boss 21A.
Second and third arms 21B2 and 21B3 provided in a forked shape at the tip of the _first arm 21B1, and _second and _third arms 21B2 and 21B3.
Fan-shaped plate 21 covering the upper surfaces of the arms 21B ₂ and 21B ₃
Is composed of a B _4, 2 two arms 21B adjacent to the boss portion 21A, the space surrounded by the 21B forming the bucket accommodating portion 24. The first arm 21B
₁ has the same height as the boss portion 21A, and the lower surface thereof is in close contact with the upper surface of the bottom plate 20B of the windshield case 20, and is fixed by a set screw 33 (FIG. 1). The second and third arm portions 21B ₂ and 21B ₃ are formed to have a smaller dimension in the height direction than the first arm portion 21B _1, so that an appropriate gap G ₁ ( FIG. 1) is set. The outer surfaces (opposing surfaces) of the second and third arms 21B ₂ , 21B ₃ of the two adjacent arms 21B, 21B oppose each other.
25b are formed, and the trunnion pins 26 are protruded.

[0021] The fan-shaped plate portion 21B ₄ has an upper surface that the boss portion 21A, forms a first upper surface and the same surface of the arm portion 21B _1, the outer periphery is fitted into the windshield wall 20A of the windshield case 20 I agree.

The bucket 22 is made of a molded product made of an aluminum alloy and integrally formed by forging or extrusion. The bucket 22 is formed in a cylindrical shape having a substantially elliptical shape in plan view and opening downward, so that the bucket 22 has a substantially cylindrical shape. Oval upper plate 22A
And four oval tube sections 22B, each of which has an oval cylindrical section 22B integrally connected to the outer peripheral edge of the lower surface of the upper plate section 22A, and into which the tube 41 for storing the liquid sample 40 is inserted in the upper plate section 22A. The holes 42 are formed so as to be located on the same circumference at equal intervals in the circumferential direction, and communicate with the inside of the cylindrical portion 22B.

The cylindrical portion 22B has the same outer shape as the upper plate portion 22A in plan view, and has two flat plate portions 44 opposed in the long axis direction (axial direction of the trunnion pin 26).
a, 44b and two flat plate portions 45a, 45a facing each other in the short axis direction (the direction orthogonal to the axis of the trunnion pin 26).
45b and these flat plate portions 44a, 44b, 45a, 4
4b connecting four convex curved surface portions 46a to 46d (FIG. 5)
And two flat plate portions 4 facing each other in the major axis direction.
A long groove 47 into which the protruding end of the trunnion pin 26 is inserted is formed in the axial direction of the bucket 22 at 4a, 44b. The upper end of the long groove 47 has flat plate portions 44a, 4a.
4b is located near the upper end, and the lower ends are flat plate portions 44a, 44b.
It is open at the lower end. The bucket 22 is formed in a symmetrical shape with respect to the major axis and the minor axis, respectively.
It is possible to attach to.

In FIG. 3, the opening of the tube 41 after the liquid sample 40 is stored is hermetically closed by a lid 50, and the tube 41 is inserted into the tube insertion hole 42 of the bucket 22 from above.

When the bucket 22 is mounted on the bucket storage section 24 of the bucket holding member 21, the bucket 22 is positioned above the bucket storage section 24 so that the long groove 47 is positioned directly above the right and left trunnion pins 26. Adjust the orientation. Then, the bucket 22 is inserted into the bucket storage section 24 from above, and the trunnion pin 26 is engaged with the long groove 47. When the bucket 22 is inserted into the bucket storage portion 24 by a predetermined amount, the trunnion pin 26 is moved to the upper groove wall 47 a of the long groove 47.
(FIG. 3), and the bucket 22 is rotatably suspended and supported.

In the centrifugal separator 1 having such a structure, when the drive motor 3 is driven by energization to rotate the drive shaft 4, the swing rotor 5 rotates at high speed integrally with the drive shaft 4 (for example, at 12,000 rpm). ) To give a centrifugal force to the bucket 22. For this reason, the bucket 22 uses the trunnion pin 26 as a fulcrum of rotation by the centrifugal force and the arrow A in FIG.
The tube 41 is turned approximately 90 degrees in the direction B and turned sideways.
The sample having a high density of the liquid sample 40 in the
The low density sample is moved radially inward and centrifuged.

When the bucket 22 is mounted on the bucket storage portion 24, the upper end of the bucket 22 is supported by the trunnion pin 26. Therefore, the bucket 22 does not normally rotate and turn upside down. If the hand is accidentally touched or turned over during operation or the like, the trunnion pin 26 will lose its support.
And falls on the bottom plate 20B of the windshield case 20.

Therefore, in the present invention, in order to prevent such a reversal and dropping of the bucket 22, the bucket 2 is further provided on each of the side walls 25 a and 25 b of each of the bucket storage sections 24.
2 is provided with a rotation restricting portion 52 for restricting the rotation angle to about 90 °. The rotation restricting portion 52, FIG. 2, together toward the center of the bucket accommodating portion 24 from the respective side walls 25a, 25b upper and side surfaces of the fan-shaped plate portion 21B ₄ of 4 and 5 It is composed of a protruding eave-like projection. For this reason, the width of the bucket storage portion 24 is smaller on the distal end side than the width of the bucket 22 in the long axis direction. The position where the rotation restricting portion 52 is formed depends on the trunnion pin 26.
From a more positions not hindrance to attachment and detachment of the bucket 22 on the outside periphery of the fan-shaped plate portion 21B _4, the upper surface in the state which became sideways particular by approximately 90 ° pivoting bucket 22 during centrifugation (Fig. 5 At the convex curved surface portions 46a, 46b)
There may be within the range of contact, in the present embodiment shows an example in which with a length extending to the outer periphery of the plate portion 21B _4. Further, the rotation restricting portion 52, the reverse triangular cross-sectional shape as shown in FIG. 5, the upper surface 52a forms an upper surface flush with the fan-shaped plate portion 21B _4, the slope 52b
Are convex curved surface portions 46a, 46 of the cylindrical portion 22B of the bucket 22.
b, 46c, and 46d are formed on an arc surface with substantially the same radius of curvature.

As described above, each side wall 2 of the bucket storage portion 24
If the rotation restricting portions 52 are provided on the 5a and 25b,
G22 is 90 ° in the direction of arrow A from the vertical state shown in FIG.
The operator cannot carelessly touch the
It will turn over and fall off from the trunnion pin 26
There is no such thing. In addition, rotation in the direction opposite to the direction A in FIG.
About the boss 21A of the bucket holding member 21 and the bucket.
Spacing G with ket 22 _Two Is set so narrow that
Will not turn.

FIGS. 6 to 8 show another embodiment of the present invention. FIG. 6 is a plan view showing a part of the swing rotor when it is not used, and FIG. FIG. 8 is a plan view showing a part of the processing state in a broken state.
It is a VIII-VIII line expanded sectional view. The same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, a protrusion 60 is provided on each of the side walls 25a, 25b of the bucket storage portion 24, and the protrusion 6
An example in which 0 is used as a rotation restricting portion that restricts the rotation of the bucket 22 is shown. In this case, in the present embodiment, screw holes are provided in the side walls 25a and 25b, a set screw 61 is screwed into the screw holes, and the head is
Although an example using 0 is shown, a pin-shaped member may be used instead of the set screw 61. It will be apparent that even in such a structure, the protrusions 60 can prevent the bucket 22 from turning over and falling off.

In the above-described embodiment, the example in which the rotation restricting portions (52 or 60) are provided on both side walls 25a and 25b of the bucket storage portion 24, however, the present invention is not limited to this. Not limited, bucket 2
As long as it has a shape and a structure that can prevent the inversion and dropping of the two, it may be provided on only one of the side walls. In addition, the protrusion 60 is attached to each side wall 25a, 25b by one.
The number is not limited to one, and a plurality may be provided.

[0033]

As described above, the swing rotor for a centrifugal separator according to the present invention can reliably prevent the bucket from being inverted or dropped due to an operation error or the like. Therefore, it is possible to prevent the swing rotor from rotating at a high speed in a state where the bucket is dropped. Further, since it is only necessary to provide a protrusion, even an existing product can be easily remodeled.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a centrifuge provided with a swing rotor according to the present invention.

FIG. 2 is a plan view showing a part of a swing rotor when not used, which is cut away.

FIG. 3 is an enlarged sectional view taken along line III-III of FIG. 2;

FIG. 4 is a partially cutaway plan view showing the swing rotor in a centrifugal processing state.

FIG. 5 is an enlarged sectional view taken along line VV of FIG. 4;

FIG. 6 is a partially cutaway plan view of a swing rotor showing another embodiment of the present invention.

FIG. 7 is a partially cutaway plan view showing the swing rotor in a centrifugal processing state.

8 is an enlarged sectional view taken along line VIII-VIII of FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Centrifuge, 2 ... Housing, 3 ... Drive motor, 4 ... Drive shaft, 5 ... Swing rotor, 20 ... Windshield case, 21 ... Bucket holding member, 22 ... Bucket, 24 ... Bucket storage part, 25a, 25b ... side wall, 26 ... support shaft (trunnion pin), 40 ... liquid sample, 41 ... tube, 47 ... long groove, 52 ... rotation restricting part, 60 ... protrusion, 61 ... set screw.

Claims (3)

[Claims] 1. A windshield case having a bottomed cylindrical shape that opens upward, a bucket holding member disposed in the windshield case, and a plurality of detachably and rotatably locked to the bucket holding member. A swing rotor for a centrifuge attached to a drive shaft of a drive motor, comprising: a plurality of buckets, wherein a plurality of buckets are stored in the bucket holding member; Parts are provided radially at equal intervals in the circumferential direction, a pair of support shafts engaged with the long grooves on the side wall of each bucket storage portion, and a rotation restricting portion that restricts the rotation angle of the bucket. A swing rotor for a centrifuge, comprising: 2. The swing rotor for a centrifuge according to claim 1, wherein the rotation restricting portion is integrally provided on a side wall of the bucket storage portion. 3. The swing rotor for a centrifuge according to claim 1, wherein the rotation restricting portion is a protrusion protruding from a side wall of the bucket storage portion.