JPH0135248Y2 - - Google Patents

Description

[Detailed description of the invention] "Field of industrial application" This invention relates to a rotor mounting structure for a centrifuge that performs centrifugal separation by rotating the rotor on a sample to be separated that is attached to the rotor. be.

``Prior art'' A centrifugal separator that includes a rotor with a sample to be separated attached inside an outer box, and centrifuges the sample by rotating this rotor at a high rotational speed of, for example, 10,000 revolutions per minute. is used.

In this type of centrifuge, for example,
In order to rotate the rotor at a high rotational speed of 10,000 revolutions, the connecting and mounting part between the rotor and the rotating shaft rotated by the drive of the motor must have sufficient strength. If the strength of this connection attachment part is insufficient,
An accident may occur in which the attachment portion between the rotor and the rotating shaft breaks during rotation, and the sample to be separated is scattered. Therefore, in this type of centrifugal separator, the rotor mounting structure must be constructed with sufficient strength.

FIG. 3 is a cross-sectional view of a conventionally proposed rotor mounting structure for a centrifuge, in which an inner tank 11 is mounted inside an outer box (not shown). Inner tank 1
1 has an interior on the upper side in the figure, a rotor is attached to this inner tank 11, a sample to be separated is accommodated in this rotor, and centrifugal separation of the sample to be separated is performed by rotation of the rotor.

An insertion hole 13 is formed in the bottom plate 12 of this inner tank 11 . Through this insertion hole 13 inside the outer box,
The rotating shaft 14 is inserted into the inner tank 11 from the outside to the inside. The rotating shaft 14 is configured to rotate by being driven by a motor (not shown). On the outside of the inner tank 11, the rotating shaft 14 is connected to a ball bearing 15 in which an outer ring is fixedly provided on the bottom plate 12 of the inner tank 11, and an inner ring is positioned against a step 16 formed on the rotating shaft 14. It is inserted.

From the insertion hole 13 of the bottom plate 12 of the inner tank 11, the inner tank 1
A rotor 20 is attached to an end of a rotating shaft 14 protruding within the rotor 1 .

That is, a stepped portion 21 is formed on the protruding portion of the rotating shaft 14, and the rotating shaft 14 is formed to have a narrower diameter on the distal end side of the stepped portion 21. Step portion 2 of rotating shaft 14
A fixed body 22 is attached so as to be positioned above 1. A mounting opening 2 is provided on the bottom plate 12 side of this fixed body 22.
3 is formed, and an insertion hole 25 is formed continuously to this mounting opening 23.
4 is inserted and attached to the rotating shaft 14.

An engagement opening 31 is formed at the center of the surface of the rotor 20 that faces the fixed body 22, and an insertion hole 35 is formed at the center of the rotor 20, continuing from the engagement opening 31. Further, the end face of the fixed body 22 in the direction away from the bottom plate 12 is enlarged to serve as a contact face with the rotor 20. The center of this contact surface protrudes in a direction away from the bottom plate 12 to form an engaging body 30.

The rotor 20 is mounted on the fixed body 22 by inserting the insertion hole 35 of the rotor 20 into the protruding portion of the rotating shaft 14 and engaging the engagement body 30 with the engagement opening 31 . Mounting holes 27 are formed at a plurality of locations in the fixed body 22 and the stepped portion 21 of the rotating shaft 14 that is in contact with the fixed body 22 so that both plate surfaces communicate with each other, and joint pins 26 are inserted into the mounting holes 27.

In this way, the engaging body 30 of the fixed body 22 is engaged with the engaging port 31 of the rotor 20, and the fixed body 22 and the rotor 20 are connected to each other by the screws 32 at a plurality of positions outside the engaging body 30. fixed to each other.

Further, a screw hole 40 is provided on the protruding end surface of the rotating shaft 14.
is formed, and a screw 41 is screwed into the screw hole 40 through a washer 43 disposed so as to close the open end surface of the insertion hole 35, thereby fixing the rotating shaft 14 to the rotor 20 also at the distal end portion.

The peripheral edge of the rotor 20 is connected to the bottom plate 12 on the outside.
A sample accommodating section 20-S is provided which is inclined so as to approach the sample accommodating section 20-S, and an accommodating hole 36 formed in this sample accommodating section
The test tube in which the sample to be separated was collected is housed in the chamber. By driving a motor (not shown), the rotating shaft 14 rotates at a high speed of, for example, 10,000 revolutions per minute, and centrifugation is performed on the sample in the test tube of the sample storage section 20-S.

"Problems to be solved by the invention" In the conventionally proposed centrifugal separators, the rotating shaft 14 is fixed to the rotor 20 by a screw 41, and the rotating shaft 14 is fixed to the rotor 20 by a screw 41, Rotation axis 1 also at position 32
4 is fixed to the rotor 20.

However, since the rotating shaft 14 has a narrow diameter at the stepped portion 21, the rotating shaft 14
The strength decreases discontinuously. In order to stably attach the rotor 20 to the rotating shaft 14, the stepped portion 21 is
must be formed to a certain extent. When the stepped portion 21 is made larger, the diameter of the narrow diameter portion of the rotary shaft 14 becomes smaller, and the rotary shaft 14 naturally becomes weaker at the narrow diameter portion. Moreover, due to the structure, this narrow diameter rotating shaft 1
A heavy rotor 20 is attached to the four parts, and the attached rotor 20 rotates at a high speed. Therefore, stress based on the centrifugal force generated by the rotation of the rotor 20 is concentratedly applied to this step portion 21 portion.

For this reason, the centrifugal separator accumulates fatigue effects over time due to use, concentrating on this stepped portion 21.
The strength of this part deteriorates, and this part may eventually break, resulting in damage to the centrifuge. Furthermore, if an unbalanced state occurs in the rotating mechanism of the centrifuge, stress will be concentratedly applied to the stepped portion 21, which may lead to an accident in which the centrifuge is damaged during operation. .

This invention solves the above-mentioned problems with the strength of the rotor mounting structure in conventional centrifugal separators, and makes it possible to increase the strength of the rotor's mounting on the rotating shaft. This provides a rotor mounting structure.

``Structure of the device'' In this device, an inner tank is installed inside the outer box, and an insertion hole is formed in the bottom plate of the inner tank. It is inserted and arranged. This rotating shaft is inserted into and held by a ball bearing outside the inner tank, and a rotor is attached to the end of the rotating shaft that projects from the bottom plate into the inner tank.

In this invention, the rotating shaft is formed to have approximately the same diameter from the insertion part for the ball bearing to the protruding end part to which the rotor is attached,
A cylindrical body is disposed on the inner ring of the ball bearing with the rotating shaft inserted therethrough. The end surface of this cylindrical body on the protruding end side of the rotating shaft is in contact with the end surface on the bottom plate side of the inner tank of the rotor, and the rotor is positioned on the rotating shaft by this cylindrical body and attached to the rotating shaft. It is being

``Example'' Hereinafter, the rotor mounting structure of a centrifugal separator of this invention will be described in detail based on an example using the drawings.

FIG. 1 shows the configuration of a first embodiment of this invention, in which the rotating shaft is formed to have approximately the same diameter from the portion through which the ball bearing is inserted to the protruding end portion to which the rotor is attached.

That is, a stepped portion 16 is formed on the rotating shaft 14 outside the inner tank 11, and the ball bearing 15 is positioned on the stepped portion 16 and inserted into the rotating shaft 14 with its inner ring 15-I fixed to the rotating shaft 14. will be placed. Outer ring 15-O of this ball bearing 15
is fixed to the bottom plate 12 of the inner tank 11. The rotating shaft 14 is formed to have approximately the same diameter from the portion through which the ball bearing 15 is inserted to the protruding end portion to which the rotor 20 is attached.

In the embodiment shown in FIG. 1, a minute step 45 of about 1/100 mm is formed near the end of the inner ring 15-I of the ball bearing on the rotor 20 side with respect to the rotating shaft 14. However, this minute step 45
As will be described later, this is formed for the convenience of assembly and installation, and the rotating shaft 14 starts at the step 16 position and extends approximately from the insertion part with the bearing 15 to the protruding end part which is the attachment part to the rotor 20. They are formed to have the same diameter.

First, the bearing 15 is inserted into the rotating shaft 14 from the protruding end side of the rotating shaft 14 and positioned on the stepped portion 16 . During this insertion work, the rotating shaft 1
Since the minute stepped portion 45 is formed in the bearing 4, the bearing 15 can be smoothly inserted into the rotating shaft 14, and can be moved to the stepped portion 16 position without damaging the rotating shaft 14 in the inserted state.

In this state, the bearing 15 is fixed to the bottom plate 12 of the inner tank 11 by its outer ring 15-O portion.
Further, the inner ring 15-I is fixed to the rotating shaft 14.

A cylindrical body is disposed on the inner ring of the ball bearing with a rotating shaft inserted through it, and the end face of the rotor's inner tank on the bottom plate side is in contact with the end face on the protruding end side of the cylindrical body. It is positioned in the direction of the rotating shaft and attached to the rotating shaft.

That is, the cylindrical body 50 is disposed on the end surface of the inner ring 15-I of the bearing 15 on the rotor 20 side. 1st
In the illustrated embodiment, at one end surface of the cylindrical body 50 in which the insertion hole 51 for the rotation shaft 14 is formed, the peripheral portion of the insertion hole 51 is integrally protruded along the rotation shaft 14 to form a contact body 53. The cylindrical body 50 is connected to this opposing body 53
are disposed in opposing positions on the inner ring 15-I of the bearing 15.

At one end surface of the cylindrical body 50 , a plurality of pin holes 54 are formed outside the opposing body 53 so as to penetrate through the end surface of the cylindrical body 50 . Joint pins 55 are driven into these pin holes 54, and the ends of the joint pins are arranged to protrude from the other end surface of the cylindrical body 50.

The rotating shaft 14 and the cylindrical body 50 are connected to each other by pin means (not shown) so that the rotational position is ensured. The rotor 2 is placed on this cylindrical body 50.
0 is attached. The insertion hole 35 of the rotor 20 is inserted into the rotary shaft 14 from the protruding end of the rotary shaft 14 . A mounting hole 58 having an inner diameter slightly larger than the diameter of the joint pin is formed in the end plate of the rotor 20 in the insertion direction at a position corresponding to the joint pin 55 protruding from the plate surface of the opposing cylindrical body 50. The rotor 20 is mounted on the cylindrical body 50 by inserting the joint pin 55 into the mounting hole 58.

A screw hole 60 that is continuous with the screw hole 40 formed on the protruding end surface of the rotating shaft 14 is formed in the rotor 20, and screws 41 are screwed into these screw holes 40 and 60, so that the rotating shaft 14 is connected to the rotor 20. Fixed.

The length of the cylindrical body 50 in the rotation axis direction determines the distance between the rotor 20 and the end plate of the inner ring 15-I of the bearing 15 located opposite thereto. By setting the length of the cylindrical body 50, the rotor 20 can be fixedly attached to the rotating shaft 14 at a predetermined distance from the bottom plate 12 of the inner tank 11, and an optimum rotational state can be set.

The rotating shaft 14 is substantially constant from the part where it is inserted into the bearing 15 to the end where the rotor 20 is attached, and its strength is increased.

Since the rotor 20 is attached to the rotating shaft 14 having the same diameter, stress due to the centrifugal force of the rotor is not applied locally, and age fatigue does not accumulate. In addition, even if an unbalanced state exists in the rotational drive section of the centrifugal separator, there is no place where stress is applied locally, so it is possible to prevent the accidental breakage of the rotational shaft of the centrifugal separator.

The configuration is shown in Figure 2, which is the second part of this invention.
This embodiment is an example in which this invention is applied to a rotor 20 for holding capillary tubes.

When performing a hematocrit measurement on a blood sample, the blood sample is collected into a capillary tube, and the capillary tube from which the blood sample is collected is held securely against a rotor and rotated at a high speed of, for example, 12,000 revolutions per minute. It is necessary to rotate the rotor at rotational speed to perform centrifugation.

For this reason, the rotor 20 in this case is formed into a substantially disk shape as shown in FIG. It is formed. In the example shown in FIG. 2, protrusions from the plate surface of the rotor 20 are formed on the center side and at approximately the center of the plate surface, and capillary tubes are formed radially symmetrically with respect to these protrusions. A housing groove 65 is formed.

By unscrewing the screws 41, the lid body 66 is configured to be removable from the rotor 20, and with the lid body 66 removed, capillary tubes (not shown) are inserted into the capillary tube storage grooves 65. Inset and accommodated. After accommodating the capillary tubes, the cap 66 is fitted onto the rotor 20 and the screw 41 is tightened, and the cap 67 presses the cap 66 against the rotor 20 against the biasing force of the spring 66-S. can be covered.

An elastic protector 68 is fixed to the inner circumferential end surface of the rotor 20 in the extending direction of the capillary tube receiving groove 65 . When centrifugal force is applied to the capillary tube accommodated in the capillary tube accommodation groove 65 by the rotation of the rotor 20,
The end of the capillary tube on the inner peripheral end surface side of the rotor 20 comes into contact with this elastic protector 68 . Therefore, the end of the capillary tube does not come into direct contact with the inner circumferential end surface of the rotor 20, thereby preventing the capillary tube from being damaged.

Also in this second embodiment, the bearing 15
A cylindrical body 50 is placed on the inner ring 15-I. In the second embodiment, a joint pin is not driven into the cylindrical body 50, and the cylindrical body is thin-walled, and its entire end surface is connected to the inner ring 15 of the bearing 15.
- located on I. With the rotor 20 removed, the cylindrical body 50 is inserted from the protruding end of the rotating shaft 14 and positioned on the inner ring 15-I. A pin means (not shown) is provided between the rotating shaft 14 and the cylindrical body 50 so as to pass through the shaft, so that the rotation of the rotating shaft 14 is reliably transmitted to the cylindrical body.

In this embodiment, the mounting bracket 70 is inserted through the circumferential surface of the rotating shaft 14, and the end surface of the mounting bracket 70 on the bottom plate 12 side is positioned in opposition to the end surface of the cylindrical body 50 in the protruding direction. Screw holes 71 are formed at multiple locations through the plate surface of the mounting bracket 70 and the plate surface of the rotor 20 opposing thereto, and by screwing the screws 32 into the screw holes 71, the mounting bracket 70 The rotor 20 is fixed to. Further, the mounting bracket 70 is fixed to the rotating shaft 14 by tightening the screw 41. If necessary, the fixation between the two can be strengthened by a pin fixing means inserted into the shaft (not shown).

As described above, when the screw 41 is unscrewed, the lid 66 is removed and the capillary is accommodated in the capillary tube accommodation groove 65, the lid 66 is closed and the screw 41 is tightened, so that the rotor 20 accommodates the capillary and It will be completely covered. When the rotating shaft 14 is rotated by the motor in this state, the rotation of the rotating shaft 14 is transmitted to the rotor 20, and the hematocrit value of the sample to be separated is measured.

In this embodiment as well, the rotary shaft 14 is formed to have approximately the same diameter from the insertion part into the bearing 15 to the attachment end of the rotor 20, and since there is no stepped part in the rotary shaft 14, the mechanical strength of the rotary shaft 14 is improves.

Therefore, there are no parts to which stress is applied intensively during operation of the centrifuge, and damage due to the application of concentrated stress due to the existence of an unbalanced state does not occur, and fatigue accumulates over time. There are no fragile parts, and the strength of the centrifuge's rotational drive section is dramatically improved.

"Effects of the invention" As explained above in each embodiment, in this invention, the rotating shaft rotated by the motor has approximately the same diameter from the insertion engagement part with the bearing to the protruding end part where the rotor is attached. It is formed of.
Therefore, there are no locations on the rotating shaft where stress is concentrated, and the strength for holding a heavy rotor is increased. This prevents fatigue from accumulating intensively and causing deformation over time, extending the operating life of the centrifuge. Further, even if an unbalanced state exists in the rotational drive section of the centrifugal separator, stress is not intensively applied to the rotational shaft portion, so damage accidents during operation can be prevented.

In each example, a structure in which the rotor is attached directly to the rotating shaft of the motor inside the outer box has been explained, but there is also a structure in which the rotor is rotated by transmitting the rotation of the motor to the rotating shaft with a belt. It is possible.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the configuration of a first embodiment of this invention, Figure 2 is a sectional view showing the configuration of a second embodiment of this invention, and Figure 3 is a conventional centrifuge. FIG. 3 is a cross-sectional view showing the rotor mounting structure of FIG. 11: Inner tank, 12: Bottom plate, 13: Insertion hole, 1
4: Rotating shaft, 15: Ball bearing, 15-
I: inner ring, 15-O outer ring, 16: step, 20: rotor, 35: insertion hole, 40, 60, 71: screw hole, 32, 41: screw, 45: minute step, 50:
Cylindrical body, 51: Insertion hole, 53: Opposite body, 54: Pin hole, 55: Joint pin, 58: Mounting hole, 6
6: Lid body, 65: Capillary tube accommodation groove, 68: Elastic protector.

Claims (1)

[Scope of utility model registration request] An inner tank is attached to the outer box, an insertion hole is formed in the bottom plate of the inner tank, and a rotating shaft is inserted from the outside of the inner tank to the inside of the inner tank through this insertion hole, and this rotating shaft is inserted into the outer box. In a centrifugal separator, a rotor is inserted into and held by a ball bearing on the outside of the inner tank, and a rotor is attached to an end of the rotating shaft that projects from the bottom plate into the inner tank, the rotating shaft is inserted into the ball bearing. A cylindrical body is formed to have approximately the same diameter from the insertion portion to the protruding end, and the rotating shaft is inserted into the inner ring of the ball bearing, and the cylindrical body has a diameter that is approximately the same from the insertion portion to the protruding end. The rotor is positioned on the rotating shaft by the cylindrical body with the end face of the rotor on the bottom plate side facing the end face,
A rotor mounting structure for a centrifuge, characterized in that the rotor mounting structure is mounted on the rotating shaft.