JP2009039688A - Centrifuge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safe centrifuge capable of easily opening and closing a door and securing high air tightness of a rotor chamber by preventing the opening of the door during the rotation of the rotor. <P>SOLUTION: In the centrifuge provided with a housing 1, the rotor 2 rotating while holding a sample for separation, a driving apparatus 4 for driving and rotating the rotor 2, the rotor chamber 3 having an opening part for housing the rotor 2 and taking in and taking out the rotor 2, the door 5 for opening and closing the opening part of the rotor chamber 3 and a magnet 6 disposed at the door 5 to fix the door 5 to the housing 1 by being attracted to the housing 1, a prescribed amount of movement of the door 5 is allowed while the attraction of the magnet 6 to the housing 1 is kept. For example, an elastic body 12 is provided between the magnet 6 and the door 5 to allow the movement of the door 5 by the amount of the elastic deformation of the elastic body 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a centrifuge in which a door that opens and closes an opening of a rotor chamber is fixed to a housing by a magnet.

  Generally, a centrifuge is a device that separates and purifies a sample by inserting a tube or bottle containing a sample to be separated into a rotor and rotating the rotor at a high speed. Depending on the application, product groups from low speed (maximum rotation speed of several thousand rpm) to high speed (maximum rotation speed of about 150,000 rpm) are provided.

  There are various types of rotors depending on the application, such as an angle rotor with a fixed tube hole, a swing rotor that swings from a vertical state to a horizontal state as the rotor rotates, and a bucket loaded with a tube. These various rotors can be attached to and detached from the drive unit.

  By the way, in a centrifuge, when the rotor rotates at a high speed, the temperature of the rotor rises due to the air resistance generated between the outer surface of the rotor and the air in the rotor chamber, but it is necessary to maintain a low temperature state depending on the sample. Many centrifuges are equipped with cooling devices. In particular, the high-speed centrifuge is further designed to reduce the pressure in the rotor chamber to a high vacuum or low vacuum state to avoid the influence of windage loss due to the rotation of the rotor.

  The object of application of the present invention is a centrifugal separator of a type that is equipped with a cooling device and that is operated while the rotor chamber is maintained in an atmospheric state, an example of which is shown in FIG.

  That is, FIG. 5 is a longitudinal sectional view of a conventional centrifuge, and the illustrated centrifuge includes a housing 1, a rotor chamber 3 that houses the rotor 2, a drive device 4 that rotationally drives the rotor 2, The door 5 etc. which open and close the opening part of the rotor chamber 3 are provided. Here, the rotor chamber 3 is constituted by a bowl 7 whose upper surface is open. The door 5 is pivotally attached to the housing 1 via a hinge 9, and the opening of the rotor chamber 3 is opened and closed by rotating up and down. Further, a magnet 6 is attached to the back surface of the door 5, and when the door 5 is closed as shown in the figure, the magnet 6 is in close contact with the casing 1 which is a magnetic body, and attracts the casing 1 by magnetic force. As a result, the door 5 is fixed to the housing 1.

  By the way, the drive device 4 includes a motor and is elastically supported via a plurality of vibration isolating rubbers 17 on a partition plate 16 installed in the housing 1. The drive device 4 penetrates the bowl 7 from below and faces the rotor chamber 3, and the rotor 2 is detachably mounted on the upper end thereof.

  A refrigeration pipe 8 is wound around the bowl 7, and the rotor chamber 3 is cooled through the bowl 7 by evaporation of the refrigerant flowing through the refrigeration pipe 8, and is caused by windage loss caused by the rotation of the rotor 2. Fever is suppressed. For this reason, in the centrifuge, it is necessary to thermally shut off the rotor chamber 3 and the outside and increase the air density of the rotor chamber 3. Accordingly, the periphery of the bowl 7 is covered with a heat insulating material 15 such as a foam material, and a portion of the bowl 7 through which the driving device 4 passes is hermetically sealed by a seal cover 11 made of an elastic material such as rubber.

  In order to increase the degree of sealing of the rotor chamber 3, the rotor chamber 3 needs to be a space closed to the outside except for the rotor 2 and the opening used for taking in and out of the sample. Accordingly, a packing 10 made of an elastic material is attached to the periphery of the opening of the rotor chamber 3, and when the door 5 is closed, the door 5 presses the packing 10 to bring them into close contact with each other so that the rotor chamber 3 becomes highly airtight. Thus, air does not flow out of the rotor chamber 3 while the rotor 2 is rotating. However, high airtightness here means airtightness that allows air leakage to the extent that it does not affect the cooling capacity, and vacuum seals and the like are not generally employed because of high costs.

By the way, in the conventional centrifuge, as pointed out also in Patent Document 1, the air around the rotor 2 moves in the outer peripheral direction by the centrifugal force during the rotation of the rotor 2, and as a result, the center of the rotor chamber 3 The part may become negative pressure.
JP 2000-107643 A

  In the centrifuge shown in FIG. 5, when the central portion of the rotor chamber 3 becomes negative pressure as described above, a differential pressure is generated between the central portion and the space near the driving device 4, and this differential pressure causes an external pressure. From the air flows into the rotor chamber 3. For this reason, the overall pressure inside the rotor chamber 3 is increased by the inflowing air, the door 5 receives pressure from the rotor chamber 3, and the door 5 that receives the pressure is inclined to open gradually around the hinge 9. The magnet 6 fixed to the magnet 6 is also tilted in conjunction with it. For this reason, the magnet 6 cannot be brought into close contact with the casing 1 and the contact area is reduced, so that the attractive force of the casing 1 is reduced. Further, depending on the degree of inclination of the door 5, the magnet 6 cannot attract the casing 1, and a serious problem that the door 5 opens may occur.

  In order to solve the above problem, a method of increasing the mass of the door 5 so that the door 5 does not float up can be considered. However, since the door 5 becomes heavy in this method, the door 5 is opened and closed while the rotor 2 is stopped. Work becomes difficult. As another method, it is conceivable to increase the attractive force of the magnet 6, but this method also makes it difficult to open the door 5.

  The present invention has been made in view of the above problems, and the object of the present invention is that the door can be easily opened and closed, and the door is prevented from being opened while the rotor is rotating to ensure high airtightness in the rotor chamber. It is to provide a safe centrifuge that can be made.

  In order to achieve the above object, the invention described in claim 1 is a housing, a rotor that holds and rotates a sample to be separated, a driving device that rotationally drives the rotor, and the rotor that is housed and put in and out. A rotor chamber having an opening for opening, a door for opening and closing the opening of the rotor chamber, and a magnet that is provided on the door and is attracted to the housing to fix the door to the housing The centrifuge is configured to allow a predetermined amount of movement of the door while maintaining the magnet attracted to the casing.

  According to a second aspect of the present invention, in the first aspect of the present invention, a seal member that seals the rotor chamber in close contact with the door in the closed state is attached to the periphery of the opening of the rotor chamber, and the movement of the door The amount is set to a value capable of maintaining the close contact between the door and the seal member.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, an elastic body is provided between the magnet and the door, and the door is allowed to move by an amount of elastic deformation of the elastic body. And

  The invention according to claim 4 is the invention according to claim 1 or 2, characterized in that the magnet and the door are engaged with each other with a predetermined amount of backlash, allowing the door to move by the backlash. To do.

  According to a fifth aspect of the present invention, in the invention of the fourth aspect, a countersunk hole is formed in the magnet, and a stepped pin fixed to the door is engaged with the concave and convex portions with a predetermined amount of play. It is characterized by.

  According to the first aspect of the present invention, even if the door moves by a predetermined amount, the magnet is attracted to the casing to prevent the door from opening, and according to the second aspect of the present invention, the door controlled by the magnet Since the amount of movement is set to a value that allows the seal member attached to the periphery of the opening of the rotor chamber to be kept in close contact with the door, even if the door moves by a predetermined amount, the door is prevented from opening while the rotor is rotating. Thus, high airtightness can be secured in the rotor chamber, and the safety of the centrifuge can be improved.

  Moreover, since the door can be prevented from opening without increasing the mass of the door or increasing the attractive force of the magnet, it is possible to easily open and close the door without impairing the opening and closing of the door. it can. Furthermore, since it is not necessary to seal the rotor chamber with a vacuum seal or the like, high airtightness can be secured in the rotor chamber with an inexpensive configuration.

  According to the invention described in claim 3, while allowing the door to move by the amount of elastic deformation of the elastic body provided between the magnet and the door, the magnet is brought into close contact with the housing to prevent the door from opening. High airtightness can be secured in the rotor chamber.

  According to the fourth and fifth aspects of the present invention, the door is allowed to move by the amount of back-and-forth engagement between the magnet and the door, but the magnet is brought into close contact with the housing to prevent the door from being opened. High airtightness can be ensured.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
1 and 2 are longitudinal sectional views of the centrifuge according to the first embodiment of the present invention. FIG. 1 shows a state where the door is not inclined, and FIG. 2 shows a state where the door is inclined.

  The centrifuge according to the present embodiment includes a casing 1 made of magnetic metal, a rotor chamber 3 that houses a rotor 2, a drive device 4 that rotationally drives the rotor 2, and an opening of the rotor chamber 3 that opens and closes. 5 etc. Here, the rotor chamber 3 is constituted by a bowl 7 whose upper surface is opened, and the bowl 7 is constituted by a material having high corrosion resistance such as stainless steel. The door 5 is pivotally attached to the housing 1 via a hinge 9, and the opening of the rotor chamber 3 is opened and closed by rotating up and down.

  Thus, in the present embodiment, the magnet 6 is attached to the back surface of the door 5 via the elastic body 12, and when the door 5 is closed as shown, the magnet 6 is a magnetic body. The door 5 is fixed by adhering to the body 1 and attracting the housing 1 by magnetic force.

  By the way, the drive device 4 includes a motor and is elastically supported via a plurality of vibration isolating rubbers 17 on a partition plate 16 installed in the housing 1. The drive device 4 penetrates the bowl 7 from below and faces the rotor chamber 3, and the rotor 2 is detachably mounted on the upper end thereof.

  A refrigeration pipe 8 is wound around the bowl 7, and the rotor chamber 3 is cooled through the bowl 7 by evaporation of the refrigerant flowing through the refrigeration pipe 8, and is caused by windage loss caused by the rotation of the rotor 2. Fever is suppressed. For this reason, in the centrifuge, it is necessary to thermally shut off the rotor chamber 3 and the outside and increase the air density of the rotor chamber 3. Accordingly, the periphery of the bowl 7 is covered with a heat insulating material 15 such as a foam material, and a portion of the bowl 7 through which the driving device 4 passes is hermetically sealed by a seal cover 11 made of an elastic material such as rubber.

  In order to increase the degree of sealing of the rotor chamber 3, the rotor chamber 3 needs to be a space closed to the outside except for the rotor 2 and the opening used for taking in and out of the sample. Accordingly, a packing 10 made of an elastic material is attached to the periphery of the opening of the rotor chamber 3, and when the door 5 is closed, the door 5 presses the packing 10 to bring them into close contact with each other to keep the rotor chamber 3 highly airtight. The air is prevented from flowing out from the rotor chamber 3 while the rotor 2 is rotating.

  In such a centrifuge, when the rotor 2 rotates at a high speed in the rotor chamber 3, the air around the rotor 2 moves in the outer circumferential direction by centrifugal force, so that the central portion of the rotor chamber 3 becomes negative pressure. . For this reason, a differential pressure is generated between the central portion of the rotor chamber 3 and the space in the vicinity of the drive device 4 outside, and air flows into the rotor chamber 3 through the gap of the drive device 4 due to this differential pressure. For this reason, the total pressure inside the rotor chamber 3 rises due to the inflowing air, and the door 5 receives the pressure from the rotor chamber 3 and moves and tilts in the opening direction as shown in FIG.

  Thus, in this embodiment, since the elastic body 12 is provided between the magnet 6 and the door 5, the movement of the door 5 by the amount of elastic deformation of the elastic body 12 is maintained while the magnet 6 is in close contact with the housing 1. Permissible. Here, the amount of elastic deformation of the elastic body 12 (the amount of movement of the door 5) is set smaller than the crushing allowance of the packing 10, and even if the door 5 moves in the opening direction and tilts as shown in FIG. The close contact between the door 5 and the packing 10 is maintained, and the door 5 is opened so that no gap is generated between the door 5 and the packing 10. For this reason, the adhesion of the magnet 6 to the housing 1 is maintained, the suction force of the housing 1 of the magnet 6 can be kept high, and the door 5 is prevented from opening to ensure high airtightness in the rotor chamber 3. Thus, the outflow of air from the rotor chamber 3 can be prevented and the safety of the centrifugal separator can be improved.

  Further, since the door 5 can be prevented from opening without increasing the mass of the door 5 or increasing the attractive force of the magnet 6, the door 5 can be easily opened and closed without being damaged. Can be opened and closed.

  Furthermore, since it is not necessary to seal the rotor chamber 3 with a vacuum seal or the like, high airtightness can be secured in the rotor chamber 3 with an inexpensive configuration.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.

  3 and 4 are longitudinal sectional views of the centrifuge according to the second embodiment of the present invention. FIG. 3 shows a state where the door is not tilted, and FIG. 4 shows a state where the door is tilted. The same elements as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and the repetitive description thereof will be omitted below.

  In the present embodiment, a counterbore hole 13 is formed in the magnet 6, and a stepped pin 14 protrudes from the back surface of the door 5, and the stepped pin 14 is predetermined in the counterbore hole 13 of the magnet 6. The protrusions and recesses are engaged with the backlash. Here, the backlash formed between the stepped pin 14 and the counterbore hole 13 is adjusted in advance so as to be smaller than the crushing allowance of the packing 10.

  Thus, when the door 5 moves in the opening direction about the hinge 9 and tilts as shown in FIG. 4 because the pressure in the rotor chamber 3 is increased by the rotation of the rotor 2 in the rotor chamber 3, the door The inclination of 5 is absorbed by the play between the stepped pin 14 and the counterbore hole 13, and the magnet 6 is kept in close contact with the housing 1 even when the door 5 is lifted. Here, since the backlash formed between the stepped pin 14 and the counterbore hole 13 is set smaller than the crushing allowance of the packing 10 as described above, the door 5 moves in the opening direction as shown in FIG. Even if the door 5 is tilted, the close contact between the door 5 and the packing 10 is maintained, the door 5 opens and no gap is generated between the door 5 and the packing 10.

  Therefore, according to the present embodiment, the adhesion of the magnet 6 to the casing 1 is maintained, the suction force of the casing of the magnet 6 can be kept high, the door 5 is prevented from opening, and the rotor chamber 3 is high. Airtightness can be ensured, the outflow of air from the rotor chamber 3 can be prevented, and the safety of the centrifuge can be improved.

  Moreover, since the door 5 can be prevented from opening without increasing the mass of the door 5 or increasing the attractive force of the magnet 6 as in the first embodiment, the openability of the door 5 is impaired. The door 5 can be easily opened and closed.

  The present invention can be applied to a centrifugal separator of a type in which a rotor is rotationally driven in the rotor chamber while being cooled by a cooling device while keeping the rotor chamber in an atmospheric state.

It is a longitudinal cross-sectional view of the state which the door of the centrifuge which concerns on Embodiment 1 of this invention does not tilt. It is a longitudinal cross-sectional view of the state which the door of the centrifuge which concerns on Embodiment 1 of this invention inclines. It is a longitudinal cross-sectional view of the state which the door of the centrifuge which concerns on Embodiment 2 of this invention does not tilt. It is a longitudinal cross-sectional view of the state in which the door of the centrifuge which concerns on Embodiment 2 of this invention inclined. It is a longitudinal cross-sectional view of the conventional centrifuge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing | casing 2 Rotor 3 Rotor chamber 4 Drive apparatus 5 Door 6 Magnet 7 Bowl 8 Refrigeration piping 9 Hinge 10 Packing (seal member)
DESCRIPTION OF SYMBOLS 11 Seal rubber 12 Elastic body 13 Counterbore hole 14 Stepped pin 15 Heat insulating material 16 Partition plate 17 Anti-vibration rubber

Claims (5)

A case, a rotor that holds and rotates a sample to be separated, a driving device that rotationally drives the rotor, a rotor chamber that has an opening for housing and removing the rotor, and the rotor chamber In a centrifuge provided with a door that opens and closes an opening, and a magnet that is provided on the door and is attracted to the casing to fix the door to the casing.
A centrifuge configured to allow a predetermined amount of movement of the door while holding the magnet attracted to the casing.   At the periphery of the opening of the rotor chamber, a seal member that seals the rotor chamber in close contact with the door in the closed state is attached, and the amount of movement of the door is set to a value that can maintain close contact between the door and the seal member. The centrifuge according to claim 1, which is set.   The centrifuge according to claim 1 or 2, wherein an elastic body is provided between the magnet and the door, and the movement of the door is allowed by an amount of elastic deformation of the elastic body.   The centrifuge according to claim 1 or 2, wherein the magnet and the door are engaged with each other with a predetermined amount of backlash to allow movement of the door by the backlash. The centrifuge according to claim 4, wherein a counterbore hole is formed in the magnet, and a stepped pin fixed to the door is engaged with the counterbored hole with a predetermined amount of play.

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