JP6776093B2 - Centrifuge - Google Patents

Description

The present invention relates to the structure of a centrifuge (centrifuge) that separates a sample by rotating a rotor containing the sample at high speed.

A centrifuge is used to separate a sample (for example, culture solution, blood, etc.) into substances having different densities by centrifugal force at high speed rotation, or to purify or analyze the sample. In the centrifuge, a rotor that internally mounts a plurality of sample containers into which samples are injected is mounted on a rotating shaft and rotates at a high speed of, for example, about 20000 rpm at the maximum. Therefore, during operation, a configuration is required in which a rotating shaft rotating at high speed is stably supported by bearings.

At this time, when the weight distribution around the central axis of the rotating shaft is symmetrical and the center of gravity of the rotating portion, for example, the entire rotor is on the central axis, vibration during rotation does not occur. However, in reality, the center of gravity does not always coincide with the central axis depending on the condition of the sample in the rotor, for example, the balance of the sample volume injected into each sample container, and the center of gravity of the rotating shaft and the center of gravity of the entire rotor do not always coincide with each other. Vibration occurs when the position shifts. If the amplitude of this vibration becomes large, a large load is applied to the rotating shaft itself and the bearings that support it, which may impair its durability. Therefore, measures are required to prevent the amplitude of this vibration from increasing. To. Here, in general, in a single centrifuge, a plurality of types of rotors are selected and used, and the amount (weight) of the sample to be accommodated also varies depending on the processing content, and such a vibration situation. Varies depending on the type of rotor, the amount of sample, the rotation speed, and the like.

As described in Patent Document 1, the amplitude of such vibration becomes particularly large due to resonance near the natural frequency of the rotating shaft, so that the rotational speed (rotational speed per unit time) and the natural frequency of the rotating shaft become large. Significantly different situations are preferred. Therefore, for example, when rotating a light rotor at high speed, it is preferable to use a rotating shaft having a low natural frequency, and when rotating a heavy rotor at a relatively low speed, it is preferable to use a rotating shaft having a high natural frequency. preferable. Here, the natural frequency is determined by the shape / dimensions of the rotating shaft and the elastic modulus. Generally, the natural frequency is low when the rotating shaft is easily elastically deformed, and the natural frequency is low when the rotating shaft is hard to be elastically deformed and has high rigidity. Will be higher. For this reason, ideally, it is desirable to select the rotating shaft according to the situation, but if the rotating shaft is replaced for each process, the burden on the operator will be heavy, so it is suitable for most expected cases. It is preferable to use a rotating shaft that can be used.

In order to make a single rotating shaft correspond to such various cases, Patent Document 2 describes a shaft having high rigidity and a high natural frequency (high rigidity shaft) and a shaft having low rigidity and a low natural frequency (a shaft having a low natural frequency). It is described that a rotating shaft combined with an elastic shaft) is used. In this case, the motor that rotationally drives the rotating shaft extending in the vertical direction is located below, and the rotor mounted on the rotating shaft is located above. In the rotating shaft, the high-rigidity shaft is combined so as to be located below (motor side) and the elastic shaft is located above (rotor side), and the lower high-rigidity shaft is supported by a bearing. Since the elastic shaft is fixed to the high-rigidity shaft at the lower end side and is not directly supported by the bearing, it is possible to vibrate with a small amplitude with respect to the high-rigidity shaft. Here, since the high-rigidity shaft and the elastic shaft have different characteristics as described above, they are made of different materials, and after each is manufactured individually, they are coaxially connected to manufacture a rotating shaft. Will be done.

Japanese Unexamined Patent Publication No. 2004-64945 Japanese Unexamined Patent Publication No. 2005-58919

When the rotating shaft is formed by combining the high-rigidity shaft and the elastic shaft as described above, the elastic shaft is supported by the bearing to vibrate and deform while sufficiently securing the region where the elastic shaft can be elastically deformed on the upper side. It is necessary to secure a sufficient area on the lower side where is suppressed. That is, it is necessary to secure sufficiently wide two regions having different characteristics in the vertical direction.

On the other hand, particularly in a tabletop centrifuge, the total height is required to be low, that is, the height is low, and for this purpose, the total length of the rotating shaft is required to be shortened. For this reason, it has been difficult to secure a sufficiently wide area for each of the above two regions to realize desired characteristics. Alternatively, in order to sufficiently secure the two regions having different characteristics in the vertical direction as described above, the structure of the rotating shaft (high-rigidity shaft and elastic shaft) becomes complicated, the manufacturing cost increases, and the manufacturing thereof becomes high. The process has also become complicated. This increased the manufacturing cost of the centrifuge itself.

For this reason, an inexpensive low-profile centrifuge in which vibration during operation is suppressed has been required.

The present invention has been made in view of such problems, and an object of the present invention is to provide an invention for solving the above problems.

The present invention has the following configurations in order to solve the above problems.
Centrifuge of the present invention, have along the vertical direction, a rotary shaft which is rotatably supported by bearings is driven driven by being mounted on the upper side of the rotary shaft, a rotor which the sample is contained therein, a centrifuge having a, the rotary shaft is rotatably supported by the bearing, a high-rigidity shaft which first hole is a recess dug down from the upper side is formed along a central axis, said An elastic shaft engaged in the extending direction of the high-rigidity shaft and a second hole provided along the central shaft are formed on the upper side of the high-rigidity shaft, and the elastic shaft is formed in the second hole. A fitting member that is inserted and engaged with the first hole portion to be mounted on the high-rigidity shaft, and a fastening member that comes into contact with the fitting member from above, and an outer surface of the fastening member. It is characterized in that the inner surface of the first hole portion of the high-rigidity shaft is screwed .
The centrifuge of the present invention is characterized in that the cross-sectional shape of the second hole portion along the vertical direction is a conical shape that spreads upward.
The centrifuge of the present invention is characterized in that the inner peripheral surface of the first hole portion around the central axis and the outer peripheral surface of the fitting member around the central axis have a cylindrical shape.
In the centrifuge of the present invention, the high-rigidity shaft is rotatably supported by a first bearing provided on the upper side and a second bearing provided on the lower side, and the fitting member is the fitting member. It is characterized in that it is located below the first bearing.
In centrifuge of the present invention, the the fastening member is characterized in that the through hole of the elastic shaft Ru is inserted in the vertical direction as the air gap is formed between the outer periphery of the elastic shaft is provided ..
The centrifuge of the present invention is characterized in that the fitting member is made of a material having a coefficient of thermal expansion larger than that of the high-rigidity shaft.
The centrifuge of the present invention includes a motor that rotationally drives the high-rigidity shaft from below, and the bottom surface of the first hole is located above the magnet provided in the motor. To do.
The centrifuge of the present invention is characterized in that the high-rigidity shaft is made of a soft magnetic material.
The centrifuge of the present invention includes a rotary shaft that is rotatably supported by a bearing and extends in the vertical direction, and a rotor that is driven by being mounted on the rotary shaft and houses a sample inside. The rotary shaft is rotatably supported by the bearing and has a hole portion that is dug downward, and has a lower rigidity than the first shaft and is less rigid than the first shaft. Penetration through which the second shaft is inserted in the vertical direction with a gap formed between a second shaft having a fitting portion fitted in the hole portion on the lower side and the outer periphery of the second shaft. A fastening member having a hole, the outer surface of the fastening member and the inner surface of the hole portion in the first shaft are screwed together, and the fitting portion is fitted into the hole portion. The member is in contact with the fitting portion from above, and the second shaft is mounted on the first shaft.

Since the present invention is configured as described above, it is possible to obtain an inexpensive low-profile centrifuge in which vibration during operation is suppressed.

It is sectional drawing which shows the structure of the centrifuge which concerns on embodiment of this invention. It is sectional drawing which enlarges and shows the motor and the rotating shaft in the centrifuge which concerns on embodiment of this invention. It is sectional drawing which enlarges and shows the structure of the rotating shaft in the centrifuge which concerns on embodiment of this invention. It is an assembly drawing of the rotating shaft in the centrifuge which concerns on embodiment of this invention. FIG. 5 is an enlarged cross-sectional view showing a motor and a rotation shaft in two examples of a conventional centrifuge.

The centrifuge according to the embodiment of the present invention will be described. Similar to the centrifuge described in Patent Document 2, the rotating shaft used in this centrifuge is configured by combining a high-rigidity shaft and an elastic shaft. FIG. 1 is a cross-sectional view in the vertical direction along the axis of the rotating shaft 10 showing the configuration of the centrifuge 100.

In FIG. 1, the rotor 20 is provided in the rotor chamber 21A surrounded by the bowl 21, and is detachably mounted on the upper portion of the rotating shaft 10. The rotary shaft 10 and the rotor 20 are rotationally driven by a motor 30 provided on the lower side of the rotary shaft 10 in a state where the upper side of the rotor chamber 21A is sealed by the lid portion 22. The motor 30, bowl 21, and the like are fixed to the housing 23.

Inside the rotor 20, sample containers (not shown) in which samples to be centrifuged are injected are arranged and installed concentrically. Further, there are a plurality of types (size, structure) of the rotor 20, and the user selects this type according to the processing content. The mounting structure of the rotor 20 with respect to the upper portion of the rotating shaft 10 is the same as that conventionally known. Although a mechanism for controlling the rotation of the motor 30 and the temperature of the bowl 21 is actually provided in the housing 23, the description thereof is omitted in FIG. 1 because it is irrelevant to the present invention. ing.

FIG. 2 is a cross-sectional view taken along the central axis 10A of the rotating shaft 10 showing an enlarged configuration of the motor 30 and the rotating shaft 10 in FIG. Here, the rotating shaft 10 includes a large-diameter high-rigidity shaft 11 integrated with the rotor 31 of the motor 30 on the lower side, and an elastic shaft 12 fixed coaxially with the high-rigidity shaft 11. The high-rigidity shaft 11 is rotatably supported in the motor housing 32 by the upper first bearing (ball bearing) 33A and the lower second bearing 33B. Further, in the high-rigidity shaft 11, a balance ring 11A for balancing the rotating shaft 10 is provided in a region between the rotor 31 and the first and second bearings 33A and 33B in the upper and lower parts, respectively. .. Further, a stator (magnet) 34 is fixed to the motor housing 32 at the same height as the rotor 31 and on the outside thereof. The rotor 31 is composed of a permanent magnet, the stator 34 is composed of an electromagnet, and by controlling the current flowing through the stator 34, the high-rigidity shaft 11 (rotating shaft 10) to which the rotor 31 is fixed is rotated. Can be driven.

The high-rigidity shaft 11 is preferably made of a soft magnetic material and a highly rigid material. Since the high-rigidity shaft 11 is a soft magnetic material, in the configuration of FIG. 2, the high-rigidity shaft 11 becomes a passage for magnetic flux by the magnet 34, leakage of magnetic flux is suppressed, and a large torque is generated for the rotor 31. Can be done. Further, by increasing the rigidity of the high-rigidity shaft 11, the natural frequency of the high-rigidity shaft 11 can be increased. This makes it easy to support the high-rigidity shaft 11 with the first and second bearings 33A and 33B. Specifically, martensitic SUS steel can be used as the material constituting the high-rigidity shaft 11.

On the other hand, as the material constituting the elastic shaft 12, it is preferable to use a material having a wide elastic deformable region and a large toughness, and specifically, an oil tempered wire for a spring can be used. Further, since the high-rigidity shaft 11 and the elastic shaft 12 are made of different materials in this way, both are separately molded and manufactured.

FIG. 3 is a particularly enlarged view of the upper portion of the high-rigidity shaft 11 and the vicinity of the lower portion of the elastic shaft 12 in FIG. In the rotating shaft 10, the fitting member 13 and the fastening member 14 are used when the elastic shaft 12 is coaxially fixed to the high-rigidity shaft 11. Therefore, when the elastic shaft 12 is fixed to the high-rigidity shaft 11, they do not come into direct contact with each other. FIG. 4 is an assembly view of the high-rigidity shaft 11, the fitting member 13, the elastic shaft 12, and the fastening member 14.

As shown in FIG. 4, the high-rigidity shaft 11 is formed with a first hole portion 11B, which is a hole portion dug down from the upper surface thereof along the central shaft 10A. The bottom surface 11B1 of the first hole portion 11B is formed so as to be higher than the rotor 31. The first hole portion 11B is roughly classified into a lower region 11B2, which is a region on the bottom surface 11B1 side, and an upper region 11B3 on the upper side thereof in the vertical direction. The inner peripheral surface of the lower region 11B2 has a cylindrical shape centered on the central axis 10A, and the inner peripheral surface of the upper region 11B3 has a similar cylindrical shape, but the inner peripheral surface is threaded. ing.

The fitting member 13 includes a cylindrical outer peripheral surface corresponding to the inner peripheral surface of the lower region 11B2 in the first hole portion 11B, and as shown in FIG. 3, the lower region on the bottom side of the first hole portion 11B. It is provided in 11B2. Further, as shown in FIG. 4, the fitting member 13 is formed with a second hole portion 13A, which is a hole portion dug down along the central axis 10A from the upper side thereof. In this configuration, the second hole portion 13A is formed so as to penetrate the fitting member 13 in the vertical direction. The cross-sectional shape of the second hole portion 13A in FIG. 3 is a tapered (conical) shape with the upper side slightly widened, and the taper angle is as small as about 1 °.

Further, the elastic shaft lower portion 12A, which is a region on the lower side of the elastic shaft 12, has a tapered shape corresponding to the tapered shape of the second hole portion 13A. Therefore, in the state before the fitting member 13 is mounted in the first hole portion 11B, the elastic shaft 12 (elastic shaft lower portion 12A) is fitted into the second hole portion 13A from above, and the fitting member 13 and the elastic shaft are fitted. It is possible to integrate and fix the twelve. After that, in this state, the fitting member 13 can be fitted into the first hole portion 11B of the high-rigidity shaft 11 from above.

Further, the fastening member 14 is provided with a through hole 14A that penetrates the fastening member 14 in the vertical direction. On the other hand, the outer peripheral surface 14B on the lower side of the fastening member 14 is threaded to be screwed with the first hole portion 11B. Therefore, when the fitting member 13 and the elastic shaft 12 are mounted, the fastening member 14 is inserted from above in the first hole portion 11B with the elastic shaft 12 inserted through the through hole 14A in the vertical direction. And the outer peripheral surface 14B is fixed by abutting with the inner surface of the first hole portion 11B. Therefore, the fastening member 14 is fixed to the high-rigidity shaft 11 and the fitting member 13. On the other hand, at the time of fixing, a gap is formed between the elastic shaft 12 penetrating the through hole 14A in the vertical direction and the inner peripheral surface of the through hole 14A. Therefore, the elastic shaft 12 can be elastically deformed (vibrated) slightly in the region above the fitting member 13. On the other hand, the elastic shaft 12 is fixed to the fitting member 13 or the high-rigidity shaft 11 on the lower side of this region.

In forming the above configuration, first, the high-rigidity shaft 11, the elastic shaft 12, the fitting member 13, and the fastening member 14 are individually molded and manufactured. After that, in the positional relationship shown in FIG. 4, the lower end of the elastic shaft 12 is attached to the elastic shaft with the elastic shaft 12 inserted through the through hole 14A from above, and the lower end of the elastic shaft 12 is attached to the fitting member 13. It is fixed by press-fitting it into the two-hole portion 13A from above. After that, the fitting member 13 in which the elastic shaft 12 is press-fitted is fitted into the first hole portion 11B and fixed. At this time, an adhesive may be used. In this state, the structure of FIG. 3 can be formed by tightening the fastening member 14 from above until it is locked to the fitting member 13 and screwing it into the first hole portion 11B to fix it.

As shown in FIG. 2, in the vertical direction, the high-rigidity shaft 11 is vertically supported by the first and second bearings 33A and 33B, respectively, whereby the entire rotating shaft 10 is supported. On the other hand, as shown in FIG. 3, the fitting member 13 is in a state where the first hole portion 11B is formed deeper than a certain height of the upper first bearing 33A and the fitting member 13 is mounted. It can be configured so that it is located at a position lower than the bearing 33A of 1. Even in such a case, the first hole portion 11B does not adversely affect the support of the high-rigidity shaft 11 by the first bearing 33A. Further, in the vertical direction, the elastic shaft 12 is firmly fixed to the high-rigidity shaft 11 in the region where the fitting member 13 is located.

On the other hand, as described above, the elastic shaft 12 can vibrate in the region above the fitting member 13 located below the first bearing 33A. Therefore, in the above configuration, while the elastic shaft 12 sufficiently secures a region where the elastic shaft 12 can be elastically deformed on the upper side, the high-rigidity shaft 11 is supported by the first and second bearings 33A and 33B, and vibration and deformation occur. It is possible to secure a sufficient area to be suppressed on the lower side without increasing the total length of the rotating shaft 10.

In addition, this structure can be easily and inexpensively manufactured as described below.

For example, in the high-rigidity shaft 11, instead of providing the first hole portion 11B, a tapered hole portion corresponding to the second hole portion 13A is provided, and the hole portion is directly provided without using the fitting member 13. The elastic shaft 12 may be fixed. 5 (a) and 5 (b) are diagrams showing two examples of structures having such a configuration in correspondence with FIG. 2.

In FIG. 5A, the fitting member 13 is not used, and the rotating shaft 110 is configured by combining the high-rigidity shaft 111 and the elastic shaft 112. A tapered hole portion 111A corresponding to the second hole portion 13A is formed on the upper portion of the high-rigidity shaft 111. The shape of the elastic shaft 112 is the same as that of the elastic shaft 12, and the tapered elastic shaft lower portion 112A of the elastic shaft 112 can be fixed to the hole 111A from above. In this case, the elastic shaft 112 can vibrate only in the region above the hole 111A. Therefore, in order to widen this region, the elastic shaft 112 is located above the high rigidity shaft 111. It is necessary to lengthen. Therefore, the total length of the rotating shaft 110 becomes long.

On the other hand, FIG. 5B is an improved structure of the structure of FIG. 5A so that the total length of the rotating shaft is shortened. In the rotating shaft 210 used in this case, the high-rigidity shaft 211 is formed with a hole 211A. The hole portion 211A is formed deeper than the hole portion 111A, and has a tapered region 211A1 having a tapered shape and provided on the bottom side in the vertical direction, and a tapered region 211A1 having a diameter larger than that of the tapered region 211A1. It is divided into a large diameter region 211A2 provided at the upper part. In this case, the taper region 211A1 corresponds to the hole portion 111A, and the elastic shaft 212 is fixed in the taper region 211A1 in the same manner as for the hole portion 111A. On the other hand, in the large diameter region 211A2 above the tapered region 211A1, the inner surface of the hole 211A and the elastic shaft 212 can be in a non-contact state, so that the elastic shaft 212 vibrates in the large diameter region 211A2. It can also vibrate above it. On the other hand, the support of the high-rigidity shaft 211 by the first and second bearings 33A and 33B is performed in the same manner as the structure of FIG. 5A. Therefore, a region where the high-rigidity shaft 211 is supported by the first and second bearings 33A and 33B and vibration and deformation are suppressed can be sufficiently secured on the lower side, and at the same time, a region where the elastic shaft 212 can vibrate. The total length of the rotating shaft 210 can be made shorter than that in the case of FIG. 5A. Therefore, the structure of FIG. 5B is preferable for reducing the height of the centrifuge.

On the other hand, since the high-rigidity shaft 211 used here is composed of the tapered region 211A1 and the large-diameter region 211A2, the hole portion 211A deeper than the hole portion 111A is formed. Here, the inner surface shape of the large diameter region 211A2 may be non-contact with the elastic shaft 112, and this shape can be a cylindrical surface shape that can be easily processed. Therefore, high accuracy is not required in the processing for forming only the large diameter region 211A2. On the other hand, since the tapered region 211A1 is formed to coaxially fix the elastic shaft 212 to the high-rigidity shaft 211, high accuracy is required in its processing. Therefore, in the end, high accuracy is required to form the deep hole portion 211A, and particularly high accuracy is required in the processing of the tapered region 211A1 which is the deepest portion thereof. In general, it is not easy to form such a deep hole with high accuracy in a steel material that constitutes the high-rigidity shaft 211, and it is not possible to manufacture such a high-rigidity shaft 211 at low cost. Have difficulty. That is, although the structure shown in FIG. 5B suppresses vibration during rotation and makes it possible to reduce the height of the centrifuge, it has been difficult to make the centrifuge inexpensive.

On the other hand, in the configuration according to the above embodiment, the hole portion 111A or the second hole portion 13A having the same tapered inner surface as the tapered region 211A1 is formed in the fitting member 13. Here, since the fitting member 13 has a shorter overall length than the high-rigidity shaft 11 and is a small component, its processing is easy, and the tapered second hole portion 13A as described above is described. It is also easy to form on the small fitting member 13. On the other hand, the first hole portion 11B is formed on the high-rigidity shaft 11 having a long overall length, but the inner surface shape of the first hole portion 11B is a cylindrical surface shape that can be easily processed as described above. Can be manufactured at low cost.

Further, in the above configuration, the fastening member 14 is mainly provided to prevent the fitting member 13 from moving upward in the first hole portion 11B. Therefore, the fastening member 14 is narrowed so as to come into contact with the fitting member 13 from above by being screwed into the first hole portion 11B in a state where the elastic shaft 12 is inserted into the through hole 14A in a non-contact manner. However, high precision is not required for the shape. Further, the fastening member 14 is also small like the fitting member 13. Therefore, the fastening member 14 can be easily manufactured. Further, if the fitting member 13 is firmly fixed in the first hole portion 11B so as not to move in the vertical direction, the fastening member 14 is unnecessary.

Further, as described above, the materials constituting the high-rigidity shaft 11 and the elastic shaft 12 have characteristics individually required for each. On the other hand, as long as the fitting member 13 and the fastening member 14 can be fixed to the high-rigidity shaft 11 together with the elastic shaft 12 as described above, the fitting member 13 and the fastening member 14 are attached to the materials constituting the fitting member 13 and the fastening member 14. There are few restrictions. Therefore, the materials that can be easily processed as described above can also be used as these materials. Further, as the material constituting the fitting member 13, the same material as that of the high-rigidity shaft 11 can be used. Alternatively, by using a material having a larger coefficient of thermal expansion than the material constituting the high-rigidity shaft 11 as the material constituting the fitting member 13, the fitting member 13 and the first hole portion 11B can be separated from each other when the temperature rises. The bond becomes stronger. Since there are fewer restrictions on the material constituting the fastening member 14 than with respect to the material constituting the fitting member 13, there is a wide range of room for material selection.

Therefore, each of the above parts can be manufactured easily and inexpensively, and the centrifuge 100 can be inexpensive.

Further, the configuration according to the above embodiment is also preferable in the operation of the motor 30 from the following viewpoints. In FIG. 2, the magnetic path through which the magnetic flux in the motor 30 passes passes from, for example, the stator 34 on the left side to the rotor 31 on the left side, passes through the central high-rigidity shaft 11, passes through the rotor 31 on the right side, and is fixed on the right side. It reaches the child 34. At this time, the high-rigidity shaft 11 is made of a soft magnetic material (ferromagnetic material), and the first hole portion 11B is provided above the magnetic path, that is, as shown in FIG. 2, the first hole portion By placing the bottom surface 11B1 of 11B above the magnetic path, the area from the left rotor 31 to the right rotor 31 in FIG. 2 can be filled with a soft magnetic material (ferromagnetic material). .. As a result, torque can be generated in the rotor 31 with high efficiency by using the magnetic field formed by the stator 34.

As described above, even when the bottom surface 11B1 of the first hole portion 11B is set higher than the rotor 31, the upper first bearing 33A is at a higher position than the rotor 31 as shown in FIG. , The bottom surface 11B1 of the first hole portion 11B or the fitting member 13 can be provided at a position lower than that of the first bearing 33A. As a result, it is possible to widen the region where the elastic shaft 12 can be elastically deformed while suppressing the total length of the rotating shaft 10. Therefore, in the above-mentioned centrifuge 100, vibration during operation is suppressed, and the centrifuge 100 can be made into a low profile type.

In the above configuration, the second hole portion 13A penetrates the fitting member 13 in the vertical direction, but the second hole portion penetrates the fitting member as long as the elastic shaft can be fixed to the fitting member. do not have to. Further, the inner surface of the second hole portion 13A and the elastic shaft lower portion 112A have a tapered shape, but these shapes are arbitrary as long as the elastic shaft lower portion can be fixed to the second hole portion.

In the above configuration, the method of fixing the fitting member to the high-rigidity shaft (first hole portion) is arbitrary. In either case, the region where the elastic shaft vibrates can be widened above the fitting member. Further, the method of fixing the fastening member to the high-rigidity shaft (first hole) is also arbitrary, and the shape thereof is also arbitrary as long as the elastic shaft can be vibrated while supporting the fitting member as described above. is there.

10, 110, 210 Rotating shaft 10A Central shaft 11, 111 High rigidity shaft 11A Balance ring 11B First hole 11B1 Bottom surface 11B2 Bottom region 11B3 Upper region 12, 112, 212 Elastic shaft 12A, 112A Elastic shaft lower 13 Fitting member 13A 2nd hole 14 Fastening member 14A Through hole 14B Outer surface 20 Rotor 21 Bowl 22 Lid 23 Housing 21A Rotor chamber 30 Motor 31 Rotor (magnet)
32 Motor housing 33A 1st bearing 33B 2nd bearing 34 Stator (magnet)
111A, 211A Hole 211A1 Taper area 211A2 Large diameter area

Claims (9)

There along the vertical direction, a rotary shaft which is rotatably supported by bearings, is driven driven by being mounted on the upper side of the rotary shaft, a centrifugal machine comprising a rotor sample is contained therein, the hand,
The axis of rotation is
Is rotatably supported by the bearing, a high-rigidity shaft which first hole is a recess dug down from the upper side is formed along the central axis,
On the upper side of the high-rigidity shaft, an elastic shaft engaged in the extending direction of the high-rigidity shaft and
A second hole provided along the central axis is formed, and the elastic shaft is inserted into the second hole and engaged with the first hole to be mounted on the high-rigidity shaft. Combined members and
A fastening member that comes into contact with the fitting member from above,
Equipped with
A centrifuge characterized in that the outer surface of the fastening member and the inner surface of the first hole portion of the high-rigidity shaft are screwed together . The centrifuge according to claim 1, wherein the cross-sectional shape of the second hole portion along the vertical direction is a conical shape that spreads upward. The centrifuge according to claim 1 or 2, wherein the inner peripheral surface of the first hole portion around the central axis and the outer peripheral surface of the fitting member around the central axis have a cylindrical shape. The high-rigidity shaft is rotatably supported by a first bearing provided on the upper side and a second bearing provided on the lower side.
The centrifuge according to any one of claims 1 to 3, wherein the fitting member is located below the first bearing. The fastening member
Any one of claims 1 to 4, wherein said elastic shaft that vertical direction is inserted through so Ru through holes are provided as gap is formed between the outer periphery of the elastic shaft The centrifuge described in. The centrifuge according to any one of claims 1 to 5, wherein the fitting member is made of a material having a coefficient of thermal expansion larger than that of the high-rigidity shaft. A motor for rotationally driving the high-rigidity shaft from below is provided.
The centrifuge according to any one of claims 1 to 6 , wherein the bottom surface of the first hole is located above the magnet provided in the motor. The centrifuge according to claim 7 , wherein the high-rigidity shaft is made of a soft magnetic material. A centrifuge including a rotating shaft rotatably supported by a bearing and extending in the vertical direction, and a rotor driven by being mounted on the rotating shaft and accommodating a sample inside.
The axis of rotation is
A first shaft that is rotatably supported by the bearing and has a hole that is dug downward.
A second shaft having a lower rigidity than the first shaft and having a fitting portion fitted in the hole portion on the lower side,
A fastening member having a through hole through which the second shaft is inserted in the vertical direction in a state where a gap is formed between the second shaft and the outer circumference of the second shaft.
Equipped with
The outer surface of the fastening member and the inner surface of the hole portion in the first shaft are screwed together, and the fastening member comes into contact with the fitting portion from above in a state where the fitting portion is fitted into the hole portion. The centrifuge is characterized in that the second shaft is mounted on the first shaft.

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