JP2601042B2 - Centrifuge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifuge for performing centrifugal separation by attaching a rotor to a rotating shaft.

[0002]

2. Description of the Related Art FIG. 2 shows a rotor holding mechanism in a conventional unbalanced type and high speed rotation type centrifuge.
Ideally, the radius r1 of the rotating shaft 1 for rotating a rotor (not shown) and the radius r3 of the coupling hole 3 should be r1 = r3. However, there is a slight gap between the rotating shaft 1 and the rotor holding surface inside the coupling hole 3 due to a limitation in machining accuracy, as is apparent from the drawing.
That is, actually, r1 ≒ r3.
Therefore, a holding member 2 which can be moved in the radial direction is attached to the upper end of the rotating shaft 1 having a tapered surface, and the coupling hole 3 is provided.
To rotate the rotor at high speed. At this time, there were only two holding positions, the contact point D of the rotating shaft 1 and the holding surface in the coupling hole 3 and the contact point E of the convex portion of the holding member 2 and the holding surface in the coupling hole 3.

[0003]

Among the conventional centrifuges, the unbalance-compatible centrifuge increases the amount of unbalance of the rotor, and the high-speed centrifuge generates abnormal vibration with high-speed rotation. Or a biting phenomenon occurs between the rotating shaft 1 and the coupling hole 3. These problems are caused by the play between the rotating shaft 1 and the coupling hole 3 caused by the two-point support described above. The method of fixing the rotor to the rotating shaft 1 by using screws or the like can eliminate the above-mentioned problems such as vibrations, but the attachment and detachment of the rotor becomes complicated and operability is deteriorated.

[0004] Accordingly, it is an object of the present invention to provide a centrifuge with good operability that eliminates abnormal vibration of the rotating shaft and the coupling hole.

[0005]

In order to achieve the above object, according to the present invention, a holding member movable in a radial direction is attached to an upper end of a rotating shaft into which a coupling hole provided in a rotor bottom is inserted. The radius of curvature of the holding member is equal to or larger than the radius of the coupling hole.

[0006]

In the centrifuge constructed as described above, the contact between the rotating shaft and the coupling hole is made at least at three points, so that the rotor is securely held and the occurrence of abnormal vibration is suppressed. Can work.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG.
FIG. 2 is a longitudinal sectional view showing a structure of a centrifuge driving unit. Rotating chamber 6
The rotor 4 housed therein has a coupling hole 3 for coupling with the rotating shaft 1. A drive device 5 is provided below the rotation chamber 6, and a rotation shaft 1 extending upward from the drive device 5 is inserted into the coupling hole 3, and the rotor 4 and the rotation shaft 1 are connected to each other, and The rotational drive of the device 5 is transmitted to the rotor 4.

FIG. 3 is an enlarged vertical sectional view of a connecting portion between the rotating shaft 1 and the rotor 4 in FIG. A groove is provided at the upper end of the rotating shaft 1 into which the coupling hole 3 is inserted, and the holding member 2 is attached to the groove. The holding member 2 and the rotating shaft 1 are connected by a spring 5, and the holding member 2 presses the coupling hole 3 in the radial direction.

The radius of curvature r2 of the holding member 2 is
It is larger than the radius r1 of the rotating shaft 1. That is, r1 <r2. Therefore, the holding member 2 pressed in the radial direction by the spring 5 comes into contact with the coupling hole 3 at two points B and C, and the rotating shaft 1 is held at three points A, B, and C. Become.

When the weight of the holding member 2 is 4.8 g and the rotation radius at the position of the center of gravity is about 8 mm, the rotation speed is set to 700
When the rotation is 00, the weight applied by the centrifugal force of the holding member 2 reaches 210 kg. Therefore, in the case of three-point holding without a play portion, the pressing force of the holding member 2 against the coupling hole 3 is more reliable. And retention is more robust.

[0011]

As described in detail above, according to the present invention,
Since the rotating shaft and the rotor coupling hole are supported at at least three points, play at the joint between the rotating shaft and the rotor coupling hole can be eliminated. Since the sticking phenomenon can be prevented, the rotor can be securely held. Further, since the structure does not require screws or the like, a centrifuge with excellent operability can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along the line OO ′ of FIG. 3 showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a conventional rotor holding state.

FIG. 3 is a longitudinal sectional view showing a connecting portion between a rotating shaft and a rotor according to one embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a structure of a driving part of the centrifuge.

[Explanation of symbols]

1 is a rotating shaft, 2 is a holding member, 3 is a coupling hole, 4 is a rotor, and 5 is a spring.

Claims (1)

(57) [Claims] 1. A centrifugal machine in which an upper end of a rotary shaft is inserted into a coupling hole provided at a bottom of a rotor to rotate a rotor, wherein a radius is formed at an upper end of the rotary shaft inserted into the coupling hole. A centrifuge wherein a holding member movable in a direction is attached, and a radius of curvature of the holding member is equal to or larger than a radius of the coupling hole.