JP3324225B2 - Centrifuge rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention is, double that houses the separated sample
A rotor body having a number of holes and an upper opening of the rotor body
The present invention relates to a heat radiation structure for a rotor for an ultra-high-speed centrifuge having a cover whose mouth can be closed .

[0002]

2. Description of the Related Art A conventional rotor for an ultrahigh-speed centrifuge (hereinafter referred to as a rotor) will be described with reference to FIG. Conventional rotors have been designed in consideration of the strength of the material, the stress applied to the rotor, simple processing shapes, and whether to use expensive alloy materials without waste. By installing a large-capacity refrigerator, the temperature of the rotor chamber could be sufficiently lowered, so that it was not necessary to pay particular attention to the heat radiation area of the rotor.

[0003]

In order to obtain a higher centrifugal acceleration in a centrifuge, it is necessary to increase the radius of rotation or
There are two ways to increase the rotation speed. Simply using these means increases the rotational stress of the rotor and destroys the rotor. Therefore, the rotor needs to be downsized to obtain a higher centrifugal acceleration. For this reason, there is a disadvantage that the heat radiation area of the rotor is reduced.
In addition, the flow of the market has come to require Freon-less electronic cooling (rotor chamber reaching temperature: about -40 ° C for refrigerators and about -20 ° C for electronic cooling) due to Freon regulations, so that the rotor chamber is maintained at a sufficiently low temperature. When the heat radiation area of the rotor becomes small, it becomes difficult to radiate heat.

An object of the present invention, the temperature of the rotor chamber even at a temperature higher than the conventional is to provide a rotor capable of maintaining a low temperature can be sufficiently cooled.

[0005]

SUMMARY OF THE INVENTION Ultrahigh-speed centrifuges usually rotate a rotor in a vacuum. Since it is in a vacuum, the heat generated by friction between the air and the rotor is almost negligible. Therefore, the amount of heat entering the rotor is only heat transfer from the rotating shaft. Since the heat transfer between the rotor chamber and the rotor is in a vacuum, it is radiant heat transfer. Equation 1 shows an equation of radiant heat transfer between the rotor chamber and the rotor.
(In order to simplify the equation, the rotor chamber was kept at a constant temperature.)

[0006]

(Equation 1)

Q: Heat transfer amount from rotor to rotor chamber σ: Stefan-Boltzmann constant TR: Temperature of rotor TC: Surface temperature of rotor chamber AR: Surface area of rotor AC: Surface area of rotor chamber εR: Emissivity of rotor surface εC : Emissivity of rotor chamber surface If Q on the left side of the equation is larger than the amount of heat transmitted from the rotating shaft to the rotor, the rotor temperature TR can be achieved. Here, the rotor and the rotor chamber surface are painted, and the case where the emissivity εR, εC = 1 is almost shown in Equation 2.

Q = σ (TR ⁴ −TC ⁴ ) AR (Equation ² ) In Equation 2, the dominant variables are the rotor temperature TR, the rotor chamber temperature TC, and the rotor surface area AR. However, the rotor temperature is determined by the cooling capacity specification of the centrifuge, and the rotor chamber temperature cannot be made sufficiently low as in the case of a refrigerator when electronic cooling is employed. Therefore , the purpose is
Cover that can close the outer periphery of the rotor and the upper opening of the rotor
By providing two disk-shaped heat radiation member, the difference between the rotor temperature and the rotor chamber temperature increases the surface area of the rotor Ru is achieved by improved to cool at least the rotor.

[0009]

[Function] The outer periphery of the rotor and the upper opening of the rotor can be closed.
By providing a disk-shaped heat radiating portion on the cover, the surface area of the rotor is increased and the cooling efficiency by radiation in vacuum can be improved, so that the temperature difference between the rotor chamber temperature as the cooling surface and the rotor temperature is small. Can cool the rotor.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. Figure 1 shows a row with multiple holes for storing separated samples .
The upper opening of the rotor body 1c and the rotor body 1c is closed.
And an ultracentrifuge rotor 1 having a cover 3
Some shows an embodiment of a chromatography data hereinafter) is a cross-sectional side view.
Hole 1a for storing separated sample in rotor body 1c
When the sample receiving hole 1a of the rotor body 1c has holes 1b for rotating shaft and the fitting of the drive unit for rotating the rotor body 1c is provided is sealed by cover 3. A disc-shaped heat radiating portion 2 (heat radiating plate) is attached to a lower portion of the rotor 1. The heat radiation part 2 is larger than the maximum outer diameter of the rotor body 1c.
And the thickness of the outer periphery of the heat radiating portion 2 is
It has a structure that is thinner than the center thickness due to the shape of the rotor, and is in close contact with the rotor 1. Here, the heat radiation part 2 is a rotor body
Care must be taken to ensure a heat transfer area with the rotor 1c, and the heat radiating portion 2 may be integrally formed with the rotor body 1c . In addition, by providing the heat dissipation unit 2 at the bottom of the rotor body 1c, increasing the rotational direction of the inertia moment of the rotor 1, it is possible to improve the rotational stability of the rotor 1 because it can lower the center of gravity of the rotor 1. FIG. 2 is a sectional view taken along the line AA
FIG. 3 is a sectional view taken along line BB of FIG. 1.
In both figures, the hatched portions in the figures are portions where high stress is generated during rotation. The bottom from a sample receiving hole 1a of the rotor 1 the heat radiating portion 2
Is provided, the restriction of the high stress generated around the sample accommodating hole 1a is eliminated, and the outer diameter of the heat radiating section 2 can be increased. The hatched portion (high stress portion) in FIG.
This is due to the mass of the outer peripheral portion, and the stress can be reduced by making the outer peripheral portion of the heat radiating portion thinner. Furthermore, by thinning the tape over path shaped as in FIG. 1, it is possible to increase the heat dissipation area. As a material of the heat sink, a metal having a specific strength equal to or higher than that of the material of the rotor body 1c is desirable as long as it is a metal. Among nonmetals, carbon fiber and aramid fiber reinforced resins with lower density than metals are promising. When the heat radiating portion 2 is formed as a separate member, it is most preferable to press-fit the heat radiating portion , and the best design is that the heat radiating portion mounting portion of the rotor expands due to centrifugal stress during rotation and appropriately presses the heat radiating portion inner diameter portion. Combining different materials and shapes.
FIG. 4 is a partially sectional side view showing another embodiment of the rotor 1 according to the present invention. The rotor body 1c and the hole 1a for housing a separate sample, and a hole 1b is provided with a rotary shaft and the fitting of the drive unit for rotating the rotor body 1c, the low
The sample accommodating hole 1a of the tab body 1c is closed by a cover 3. The cover 3 is larger than the fitting portion with the rotor body 1c.
It has a protruding disk-shaped heat radiating portion 3a.
The thickness of the outer periphery of the heat radiating portion 3a is formed smaller than the thickness of the center . Although it is possible to manufacture the cover 3 and the heat radiating portion 3a as separate members, care must be taken to ensure the close contact surface between the cover 3 and the heat radiating portion 3a, that is, the heat transfer area. FIG. 5 is a partially sectional side view showing still another embodiment of the rotor 1 according to the present invention. The rotor body 1c is provided with a hole 1a for accommodating the separated sample and a hole 1b for fitting with a rotation shaft of a driving unit for rotating the rotor body 1c .
The sample receiving hole 1a of the data body 1c is closed by a cover 3. Two disk-shaped heat radiating portions 2 are attached to the upper and lower portions of the rotor body 1c , and have a structure in which the outer peripheral portion of the heat radiating portion 2 is thinned. Heat radiating part 2 the rotor body 1
close contact with c It should be noted that to ensure the heat transfer area between the rotor body 1c. The heat radiating part 2 Rotabo
It is advantageous in terms of heat transfer if it is integrally formed with the die 1c . To give an actual example, our rotor 120A for small ultracentrifuges
T has a shape as shown in Fig. 6 and has a maximum outer diameter of 79mm, a total height of about 48mm, and an effective heat radiation area (excluding metal surfaces with low emissivity).
125 cm ² . When this was operated by a small ultracentrifuge equipped with a refrigerator, the rotor was turned off at room temperature -30 ° C.
° C. When this is operated by a small ultracentrifuge equipped with an electronic cooling device whose rotor chamber temperature drops only to −20 ° C., the rotor temperature becomes 6 ° C. This is 0 ° C even at -20 ° C
In order to be able to cool down, the heat radiation area must be increased. The required area can be obtained by solving Equation 3, where the surface area of the rotor needs to be 178 cm ² .
What is necessary is just to give the heat radiation part of 3 cm < ² > or more to the rotor 1. FIG.
In the case where the method shown in FIG. 1 is adopted, if the disc-shaped heat radiating portion 2 having a diameter of 100 mm is attached to the lower portion of the rotor body 1c, the rotor is kept at 0 ° C. even if the rotor chamber can only be cooled down to −20 ° C.
Can be cooled.

[0011] ^{σ (TR 4 -TC1 4) AR1} {εR -1 + (εC -1 -1) AR1 / AC} -1 = σ (TR 4 -TC2 4) AR2 {εR -1 + (εC -1 - 1) AR2 / AC｝ ^-1 (Equation 3) σ: Stefan-Boltzmann constant 5.669 × 1
0 ^-8 W / m ² k ⁴ TR: rotor temperature 273 k (0
° C) TC1: rotor chamber surface temperature (refrigerator) 243k (-3
TC2: rotor chamber surface temperature (electronic cooling) 253k (-2
0 ° C) AR1: Surface area of 120AT rotor 1.25 × 10
^-2 m ² AR2: Area required to cool rotor to 0 ° C. AC: Surface area of rotor chamber 0.106 m ² εR: Emissivity of rotor surface 0.9 εC: Emissivity of rotor chamber surface 0.9

[0012]

According to the present invention, the outer periphery of the rotor body is
By providing a disk-shaped heat radiating section integrally, the heat radiating surface of the rotor
The product can be increased and the heat radiation of the rotor can be performed efficiently.
Further, according to the present invention, a disk-shaped heat radiating portion is provided on the cover.
The thickness of the outer periphery of this heat radiation part is formed thinner than the thickness of the center.
This reduces the stress caused by centrifugal force and
Loss can be prevented.

[Brief description of the drawings]

FIG. 1 is a partially sectional side view showing one embodiment of a rotor for an ultracentrifuge according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a partial sectional side view showing another embodiment of the rotor for an ultracentrifuge according to the present invention.

FIG. 5 is a partial sectional side view showing still another embodiment of the rotor for an ultracentrifuge according to the present invention.

FIG. 6 is a partially sectional side view showing a conventional ultracentrifuge rotor.

[Explanation of symbols]

1 the fitting portion of the rotor, 1a is a sample receiving hole, 1b and the rotary shaft, 1c rotor body, 2 is the heat radiating portion, 3 cover, 3
a is a heat radiation part .

Claims (5)

(57) [Claims] 1. A method according to claim 1 , wherein said hole has a plurality of holes for storing separated samples.
Rotor body and upper opening of the rotor body can be closed
In centrifuge rotor having a a cover, wherein
A centrifugal separator rotor characterized in that a disk-shaped heat radiating portion is integrally provided on the outer periphery of a rotor body . 2. The rotor body is larger than a maximum outer diameter.
The heat radiating portion having a diameter is provided at a lower portion of the rotor body.
Centrifuge rotor of claim 1 wherein characterized in that that. 3. The thickness of the outer periphery of the heat radiating portion is tapered.
, Characterized by being formed thinner than the center thickness by
The rotor for a centrifuge according to claim 1 or claim 2 . 4. A plurality of said discharge members are provided on an outer periphery of said rotor body.
Centrifuge rotor of claim 1, wherein that said Rukoto provided thermal unit. 5. A rotor having a plurality of holes for storing separated samples.
Rotor body and upper opening of the rotor body can be closed
A centrifugal separator rotor having a
The cover has a disc-shaped heat radiating portion, and the outer periphery of the heat radiating portion is provided.
The thickness of is characterized by being formed thinner than the center thickness
Rotor for centrifuge.