Kneader

Abstract

Provided is a kneader (41) in which maintenance for sealing materials can be performed easily. The kneader (41) comprises: a chamber (3) including a chamber body (3a) and a bearing support part (3b); a rotor (3) including a rotor body (52) and a rotor shaft (54) that are separable from each other; a bearing part (2) that rotatably supports the rotor shaft (54) inside the bearing support part (3b); an inner sealing material (4) sealing a gap between the bearing part (2) and the rotor shaft (54); and an outer sealing material (5) sealing a gap between the bearing part (2) and the bearing support part (3). Separation of the rotor body (52) from the rotor shaft (54) allows the bearing part (2) to be drawn out from between the bearing support part (3b) and the rotor shaft (54) into a kneading space (S1) inside the chamber body (3a), and allows the bearing part (2) to be inserted in between the bearing support part (3b) and the rotor shaft (54) from the kneading space (S1).

Description

Kneading machine

[0001] The present invention relates to a kneader that kneads materials in the presence of a working fluid in a supercritical or subcritical state.

[0002] Patent Document 1 discloses a kneading machine including a rotor having a rotor shaft and a viscoseal fitted to the end of the rotor shaft on the discharge side. The viscoseal has a thread groove, and the thread groove has a groove depth that increases from the pressure side to the atmosphere side in order to prevent leakage of the kneading material.

[0003] The above-mentioned kneading may be performed in the presence of a working fluid in a supercritical or subcritical state. In the kneading machine used in this case, high airtightness is required for the chamber. In particular, high sealing performance is required for the rotor shaft. Meanwhile, since the sealing material such as the ViscoSeal is a consumable item, maintenance such as replacement of the sealing material is required.

[0004] However, since the viscoseal described in Patent Document 1 is fitted to the rotor shaft and placed in the chamber together with the rotor, the rotor must be removed from the chamber in order to perform maintenance on the viscoseal, which makes it difficult to perform maintenance on the viscoseal easily.

[0005] Japanese Patent Application Publication No. 6-87119

[0006] An object of the present invention is to provide a kneader in which maintenance of a sealing material can be easily performed.

[0007] Provided is a kneader that kneads material in the presence of a working fluid in a supercritical or subcritical state, the kneader comprising a chamber, a rotor, a bearing unit, an inner seal, and an outer seal. The chamber includes a chamber body that defines a kneading space and a bearing support unit that defines a bearing accommodating space, the kneading space and the bearing accommodating space being interconnected. The rotor includes a rotor shaft and a rotor body that are separably connected in the rotor axial direction, and the rotor shaft is disposed in the bearing accommodating space so that the rotor body kneads the material in the kneading space. The bearing unit is disposed within the bearing accommodating space between an inner circumferential surface of the bearing support unit and an outer circumferential surface of the rotor shaft so as to be detachable from the bearing support unit and the rotor shaft, and rotatably supports the rotor shaft while being supported by the bearing support unit. The inner seal seals a gap between the inner circumferential surface of the bearing unit and the outer circumferential surface of the rotor shaft. The outer seal material seals a gap between the outer peripheral surface of the bearing portion and the inner peripheral surface of the bearing support portion. The bearing portion is arranged so that, when the rotor body is separated from the rotor shaft, the bearing portion can be extracted from between the inner peripheral surface of the bearing support portion and the outer peripheral surface of the rotor shaft into the kneading space in the axial direction of the rotor, and the bearing portion can be inserted from the kneading space into between the bearing support portion and the rotor shaft in the axial direction of the rotor.

[0008] FIG. 1 is a flow sheet showing a kneading apparatus according to a first embodiment of the present invention. FIG. 2 is a diagram showing a cross section along the rotor axial direction of a kneader included in the kneading apparatus. FIG. 3 is a cross-sectional view of a main part of the kneader, showing a state in which a rotor body of the kneader is coupled to a rotor shaft. FIG. 4 is a cross-sectional view of a main part of the kneader, showing a state in which the rotor body is separated from the rotor shaft. FIG. 5 is a cross-sectional view of a kneader according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view of a kneader according to a third embodiment of the present invention. FIG. 7 is a cross-sectional view of a kneader according to a fourth embodiment of the present invention. FIG. 8 is a cross-sectional view of a kneader according to a fifth embodiment of the present invention. FIG. 9 is a cross-sectional view of a kneader according to a sixth embodiment of the present invention. FIG. 10 is a cross-sectional view of a kneader according to a seventh embodiment of the present invention. FIG. 11 is a cross-sectional view of a kneader according to a modified example of the seventh embodiment. FIG. 12 is a cross-sectional view of a kneader according to an eighth embodiment of the present invention. FIG. 13 is a cross-sectional view of a kneader according to a modified example of the eighth embodiment. FIG. 14 is a cross-sectional view of a kneader according to a reference example.

[0009] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0010] FIG. 1 shows a kneading apparatus 20 including a kneader 41 according to a first embodiment of the present invention. The kneader 41 kneads materials in the presence of a working fluid in a supercritical or subcritical state. The material in each embodiment is rubber, but it may also be resin, food, or the like. The kneading apparatus 20 performs the kneading in a batch manner.

[0011] The supercritical state is a state in which the temperature is equal to or higher than the critical temperature of the working fluid and the pressure is equal to or higher than the critical pressure of the working fluid, and the subcritical state is a state in which only one of the temperature and pressure is equal to or higher than the critical value and the other is lower than the critical value, or a state in which both the temperature and pressure are lower than the critical value but at least one of the temperature and pressure is sufficiently higher than the normal value (room temperature or normal pressure) and is close to the critical state.

[0012] Examples of materials constituting the working fluid include carbon dioxide, nitrogen, hydrogen, xenon, ethane, ammonia, methanol, and water. Of these, carbon dioxide and nitrogen are suitable for kneading rubber.

[0013] In this embodiment, carbon dioxide (CO ２) is used as the working fluid, and carbon dioxide in a supercritical state (supercritical CO ２ The kneading machine according to the present invention can also be applied to mixing in the presence of other working fluids in a supercritical state or in the presence of a working fluid in a subcritical state.

[0014] The kneading device 20 includes a production section 21 and a kneading section 22 .

[0015] The production unit 21 is a supercritical CO ２ The production section 21 includes a tank 31, a first heat exchanger 32, a pump 33, and a second heat exchanger 34.

[0016] The tank 31 contains CO ２ The first heat exchanger 32 stores the CO gas supplied from the tank 31. ２ Cool the gas to obtain liquid CO ２ Liquid CO ２ To do so.

[0017] The pump 33 pumps liquid CO ２ Pressurize the CO ２ The power required to pressurize the gas is less than that of the pump 33. ２ The pump 33 requires only a small amount of power to pressurize the liquid CO2. The pump 33 pumps the pressurized liquid CO2 downstream.

[0018] The second heat exchanger 34 is a heat exchanger for ２ is heated in a container to produce liquid CO ２ is vaporized, thereby ２ supercritical CO ２ To do so.

[0019] The kneading section 22 is a supercritical CO ２ The materials are kneaded in the presence of the mixing device 41. The kneading section 22 includes the kneader 41, an adjusting valve 42, and a separation filter 43.

[0020] In the flow path connecting the production section 21 and the kneading section 22, supercritical CO ２ Materials and additives are supplied to Supercritical CO ２ The added materials and additives are introduced into the kneader 41 .

[0021] The kneader 41 contains supercritical CO ２ The material and the additive are kneaded in the presence of supercritical CO. ２ By dissolving the hydroxybenzoate in the hydroxybenzoate, the hydroxybenzoate is quickly kneaded.

[0022] When the material is a polymer material such as rubber or resin, the additive is an additive, kneaded rubber, a plant-derived material containing cellulose nanofiber, etc. When the material is a food, the additive is a food additive, etc. The addition of the additive is optional.

[0023] When the kneading in the kneader 41 is completed, the kneaded material of the material and the additives and the supercritical CO ２ The kneaded mixture and the supercritical CO ２ is separately discharged from the mixer 41. The adjusting valve 42 controls the amount of supercritical CO2 discharged from the mixer 41. ２ In this embodiment, the adjusting valve 42 adjusts the flow rate of the supercritical CO 2 discharged from the kneader 41. ２ The pressure is reduced to CO ２ The separation filter 43 separates CO ２ The additive remaining in the gas is ２ Separate from.

[0024] The kneading device 20 further includes a return flow path 23. The return flow path 23 is used to return the CO separated from the kneaded product produced by kneading the materials. ２ The gas is allowed to flow through the return flow path 23, and the CO ２ The gas is guided to the upstream side of the first heat exchanger 32. Specifically, the return flow path 23 has an upstream end and a downstream end, and the upstream end is connected to the separation filter 43 of the kneading section 22, and the downstream end is connected to a flow path connecting the tank 31 and the first heat exchanger 32.

[0025] The return flow path 23 is for discharging the CO separated from the kneaded material in the kneading section 22. ２ The gas can be returned to the production section 21 through the return flow path 23, thereby reducing the CO 2 separated from the kneaded product.２ Allows the gas to be recycled.

[0026] The overall configuration of the kneading device 20 shown in Fig. 1 is common to the second and subsequent embodiments described later. However, the specific configuration of the kneading device including the kneader according to the present invention is not limited to that shown in Fig. 1.

[0027] As shown in FIG. 2 , the kneader 41 according to the first embodiment includes a chamber 3 , a pair of rotors 5 , and a bearing portion 2 .

[0028] The chamber 3 includes a chamber main body 3a and a bearing support portion 3b. The chamber main body 3a defines a kneading space S1, and kneading of materials takes place within the kneading space S1. The bearing support portion 3b defines a pair of bearing accommodating spaces S2, and rotatably supports the pair of rotors 5 via the pair of bearing portions 2 while accommodating the pair of bearing portions 2 within the pair of bearing accommodating spaces S2. The pair of rotors 5 knead the materials within the kneading space S1 by rotating within the chamber 3.

[0029] The kneader according to the present invention is not limited to one having a pair of rotors, but also includes a kneader having only a single rotor and a kneader having three or more rotors.

[0030] The pair of rotors 5 extend in the rotor axial direction and are arranged parallel to each other in a direction perpendicular to the rotor axial direction within the chamber 3. Each of the pair of rotors 5 includes a rotor body 52 and a rotor shaft 54 ​​aligned in the rotor axial direction. Each of the pair of rotors 5 is rotatably disposed within the chamber 3 such that the rotor shaft 54 ​​is located within the bearing accommodating space S2 and the rotor body 52 can knead the material in the kneading space S1.

[0031] The rotor body 52 includes a kneading portion 52c, a first screw portion 52a, and a second screw portion 52b. The kneading portion 52c is disposed in the kneading space S1 and kneads the material. Specifically, the kneading portion 52c has an outer peripheral surface on which spiral teeth are formed. The teeth have a shape that enables the kneading portion 52c to knead the material in the kneading space S1 as the kneading portion 52c rotates in the kneading space S1. The first screw portion 52a and the second screw portion 52b are located on both sides of the rotor body 5a in the rotor axial direction and each have a screw shape that pushes the material back into the kneading space S1 as the rotor 5 rotates.

[0032] The rotor shaft 54 ​​extends along the rotor axial direction from one of both ends of the rotor body 52 in the rotor axial direction (in this embodiment, the first threaded portion 52 a). The rotor shaft 54 ​​is disposed so as to pass through the bearing portion 2 housed in the bearing housing space S2 in the rotor axial direction, and is rotatably supported by the bearing portion 2.

[0033] In each of the pair of rotors 5, the rotor body 52 and the rotor shaft 54 ​​are connected to each other in the rotor axial direction so as to be separable from each other. Specifically, in the rotor 5 according to this embodiment, the rotor body 52 can be separated from the rotor shaft 54 ​​at a position between the first thread portion 52 a and the rotor shaft 54.

[0034] 3 is an enlarged cross-sectional view of the bearing portion 2 and its surrounding area in the kneader 41, specifically, an enlarged view of the area surrounded by the dashed dotted line III in FIG. 2. The bearing portion 2 is accommodated in the bearing accommodating space S2 so as to be detachable from the bearing support portion 3b of the chamber 3. The bearing portion 2 is cylindrical and can be disposed around the rotor shaft 54, and rotatably supports the rotor shaft 54 ​​while being supported by the bearing support portion 3b. The bearing accommodating portion 3b is located on the opposite side of the rotor shaft 54 ​​across the bearing portion 2 in the radial direction of the rotor shaft 54, i.e., outside the bearing portion 2, and supports each of the pair of bearing portions 2 over the entire circumference.

[0035] The kneader 41 further includes an inner seal 4A and an outer seal 4B. The inner and outer seals 4A, 4B are arranged to prevent fluid from leaking from the bearing accommodating space S2 in the rotor axial direction.

[0036] The inner seal material 4A is annular and seals the gap between the outer peripheral surface 54a of the rotor shaft 54 ​​and the inner peripheral surface 2n of the bearing portion 2 over the entire circumference. Specifically, an annular inner seal groove 2f is formed in the inner peripheral surface 2n of the bearing portion 2, and the inner seal material 4A is fitted into the inner seal groove 2f. The inner seal material 4A illustrated in FIG. 3 is a one-sided pressure spring-integrated seal, such as Variseal (registered trademark). However, the specific structure of the inner seal material 4A is not limited. Furthermore, the kneader 41 may be provided with a plurality of inner seal materials lined up in the rotor axial direction.

[0037] The outer seal material 4B is annular and seals the gap between the outer peripheral surface 2e of the bearing portion 2 and the inner peripheral surface 3n of the bearing support portion 3b surrounding the bearing accommodating space S2 over the entire circumference. Specifically, an annular outer seal groove 2g is formed in the outer peripheral surface 2e of the bearing portion 2, and the outer seal material 4B is fitted into the outer seal groove 2g. Alternatively, the outer seal material 4B may be fitted into an annular groove formed in the inner peripheral surface 3n of the bearing support portion 3b. The outer seal material 4B illustrated in FIG. 3 is an O-ring. However, the specific structure of the outer seal material 4B is not limited. Furthermore, the kneader 41 may include a plurality of outer seal materials arranged in the rotor axial direction.

[0038] In the kneading machine 41, the rotor body 52 is separated from the rotor shaft 54 ​​for maintenance, such as replacement, of the inner seal 4A or the outer seal 4B. This separation allows the bearing 2 to be extracted from between the inner circumferential surface 3n of the bearing support 3b and the outer circumferential surface 54a of the rotor shaft 54 ​​into the kneading space S1 in the rotor axial direction. This separation also allows the bearing 2 to be inserted from the kneading space S1 into between the bearing support 3b and the rotor shaft 54 ​​in the rotor axial direction. Therefore, maintenance related to the bearing 2, particularly replacement of the seals 4A and 4B, can be easily performed. For example, extracting the bearing 2 from between the bearing support 3b and the rotor shaft 54 ​​allows the inner and outer seals 4A and 4B to be easily replaced. This operation does not require the rotor shaft 54 ​​to be removed from the chamber 3, which makes it possible to reduce the space required around the kneader 41 compared to when the rotor body 52 and the rotor shaft 54 ​​need to be removed from the chamber 3, specifically, to eliminate the need for space to extract the rotor shaft 54 ​​from the chamber 3.

[0039] 5 shows a mixer 41 according to a second embodiment of the present invention. In the second embodiment, the mixer 141 includes all of the components of the mixer 41 according to the first embodiment, and in addition, the bearing portion 2 includes a bearing main body 2h and a protruding portion 6. The bearing main body 2h is a portion of the bearing portion 2 that is farther from the rotor main body 52 than the protruding portion 6 (the right-hand portion of the protruding portion 6 in FIG. 5), and is a portion that is inserted between the outer peripheral surface 54a of the rotor shaft 54 ​​and the inner peripheral surface 3n of the bearing support portion 3b.

[0040] The protruding portion 6 is configured by the end portion (left side in FIG. 5 ) of the bearing portion 2 in the rotor axial direction that is closer to the end of the rotor body 52 (the end face of the first threaded portion 52 a in this embodiment), and protrudes radially outward (upward in FIG. 5 ) of the bearing portion 2 beyond the outer circumferential surface of the bearing body portion 2 h. In other words, the protruding portion 6 has a thickness greater than the thickness of the bearing body portion 2 h in the radial direction of the bearing portion 2.

[0041] The protrusion 6 protrudes in the rotor axial direction beyond the bearing support portion 3b toward the rotor body 52 in a state in which the bearing body 2h is inserted between the bearing support portion 3b and the rotor shaft 54. The inner circumferential surface surrounding the protrusion 6 in the chamber 3 has an inner diameter large enough to ensure a working gap 3g between the inner circumferential surface and an outer circumferential surface 6a of the protrusion 6 that faces the inner circumferential surface in the radial direction, and the working gap 3g has a radial dimension large enough to allow insertion of fingers or a tool to grip the protrusion 6.

[0042] The protrusion 6 makes it easy to remove the bearing 2 from between the inner peripheral surface 3 n of the bearing support 3 b and the outer peripheral surface 54 a of the rotor shaft 54. Specifically, when the rotor body 52 is separated from the rotor shaft 54, an operator can grasp the protrusion 6 with his / her fingers or a tool and pull it in the rotor axial direction into the kneading space S1, thereby easily removing the bearing 2 from between the bearing support 3 b and the rotor shaft 54.

[0043] 6 shows a kneader 241 according to a third embodiment of the present invention. In this embodiment, the kneader 241 includes all of the components of the kneader 141 according to the first embodiment, and in addition, a male thread portion 7a is formed in the bearing portion 2, and a female thread portion 7b is formed in the bearing support portion 3b. Specifically, the male thread portion 7a is formed on the outer peripheral surface of the axially inner end portion, which is the end closer to the rotor body 52, of both end portions of the bearing portion 2 in the rotor axial direction. Specifically, the female thread portion 7b is formed on the inner peripheral surface of the bearing support portion 3b, which surrounds the end closer to the kneading space S1, of both end portions of the bearing accommodating space S2 in the rotor axial direction. The male thread portion 7a and the female thread portion 7b are threadably engageable with each other, and this engagement fixes the bearing portion 2 within the bearing support portion 3b.

[0044] The threaded engagement between the male thread portion 7a and the female thread portion 7b can be released by rotating the bearing portion 2 relative to the bearing support portion 3b with the rotor body 52 separated from the rotor shaft 54, whereby the bearing portion 2 can be easily extracted from between the inner circumferential surface 3n of the bearing support portion 3b and the outer circumferential surface 54a of the rotor shaft 54. Conversely, the threaded engagement between the male thread portion 7a and the female thread portion 7b fixes the bearing portion 2 to the bearing support portion 3b, preventing the bearing portion 2 from rotating together with the rotor shaft 54.

[0045] FIG. 7 shows a kneader 341 according to a fourth embodiment of the present invention. In this embodiment, the kneader 341 includes all of the components of the kneader 41 according to the first embodiment, and the bearing unit 2 also includes a magnetic portion 8. The magnetic portion 8 has a magnetic property that allows it to be attracted by a magnet and is provided at the axially inner end of the bearing unit 2, which is the end closest to the rotor body 52, of both ends of the bearing unit 2 in the rotor axial direction. The magnetic property of the magnetic portion 8 is strong enough to allow the magnetic portion 8 to be attracted by the magnet, such as a permanent magnet or an electromagnet, and to be pulled out from between the inner circumferential surface 3 n of the bearing support portion 3 b and the outer circumferential surface 54 a of the rotor shaft 54 ​​when the rotor body 52 is separated from the rotor shaft 54. Therefore, the magnetic portion 8 allows the bearing unit 2 to be easily removed using the magnet.

[0046] 8 shows a kneader 441 according to a fifth embodiment of the present invention. In this embodiment, the kneader 441 includes all of the components of the kneader 41 according to the first embodiment, and in addition, the bearing portion 2 has a threaded hole 9. More specifically, the threaded hole 9 is formed at an axially inner end portion, which is the end portion closer to the rotor body 52, of both end portions of the bearing portion 2 in the rotor axial direction, and opens toward the rotor body 52 along the rotor axial direction. The threaded hole 9 allows the male thread of a bolt or other tensioning tool having an outer circumferential surface on which a male thread is formed to be inserted into the threaded hole 9 while the male thread is threadedly engaged with the threaded hole 9.

[0047] In this way, the threaded hole 9 allows the bolt or other male threaded member to be screwed and inserted into the threaded hole 9 when the rotor body 52 is separated from the rotor shaft 54, thereby making it possible for an operator to easily remove the bearing portion 2 from between the inner surface 3n of the bearing support portion 3b and the outer surface 54a of the rotor shaft 54 ​​by grasping the pulling tool screwed into the threaded hole 9 and pulling it into the kneading space.

[0048] 9 shows a mixer 541 according to a sixth embodiment of the present invention. In this embodiment, the mixer 541 includes all of the components of the mixer 41 according to the first embodiment, but the bearing unit 2 of the mixer 541 includes a plurality of bearing elements shown in FIG. 9, namely, a first bearing element 2a, a second bearing element 2b, and a third bearing element 2c. The first to third bearing elements 2a to 2c are arranged in order from the side closest to the rotor body 52 in the rotor axial direction and are separable from one another. The number of the plurality of bearing elements is not limited to three, and may be two or four or more.

[0049] Each of the first to third bearing elements 2a to 2c has a threaded hole 9 similar to the threaded hole 9 shown in Fig. 8. Specifically, the threaded hole 9 is formed at an axially inner end of each of the first to third bearing elements 2a to 2c, and opens toward the rotor body 52 along the rotor axial direction. Each of the threaded holes 9 allows a bolt or other tensioning tool having an outer circumferential surface on which male threads are formed to be inserted into the threaded hole 9 while threadedly engaging with the threaded hole 9.

[0050] The bearing portion 2 includes a plurality of inner seals 4A and an outer seal 4B. Each of the inner seals 4A is equivalent to the inner seal 4A shown in FIG. 2, and the outer seal 4B is equivalent to the outer seal 4B shown in FIG. 2. The inner seals 4A are attached to the inner circumferential surface of the bearing portion 2 at a plurality of positions spaced apart in the rotor axial direction. Specifically, in the example shown in FIG. 9, inner seal grooves 2f are formed on the inner circumferential surfaces of the second bearing element 2b and the third bearing element 2c, respectively, and the inner seals 4A are fitted into the inner seal grooves 2f. Meanwhile, the outer seal 4B is fitted into an outer seal groove 2g formed on the outer circumferential surface of the second bearing element 2b. The inner seal 4A may be attached to the inner circumferential surface of the first bearing element 2a. The outer seal 4B may also be attached to the outer circumferential surfaces of the first bearing element 2a and the third bearing element 2c.

[0051] In the kneading machine 541, with the rotor body 52 separated from the rotor shaft 54, the first bearing element 2a, the second bearing element 2b, and the third bearing element 2c can be extracted in that order from between the inner circumferential surface 3n of the bearing support portion 3b and the outer circumferential surface 54a of the rotor shaft 54 ​​in the rotor axial direction. Specifically, an operator can easily extract each of the first to third bearing elements 2a to 2c by threading the male threads of a pulling tool into the respective threaded holes 9 of the first to third bearing elements 2a to 2c and pulling the pulling tool. Furthermore, the contact area between the outer circumferential surface of each of the plurality of bearing elements 2a to 2c and the inner circumferential surface 3n of the bearing support portion 3b is smaller than, for example, the contact area between the outer circumferential surface 2e of the bearing portion 2 shown in FIG. 2 and the inner circumferential surface 3n of the bearing support portion 3b, making it easy to extract each of the plurality of bearing elements 2a to 2c. This allows for further improvement in maintainability of the kneading machine 541. This effect becomes more pronounced as the number of the bearing elements increases.

[0052] In addition, the multiple inner sealing materials 4A seal the gap between the inner surface 2n of the bearing portion 2 and the outer surface 54a of the rotor shaft 54, thereby improving the airtightness of the kneader 541.

[0053] 10 shows a mixer 641 according to a seventh embodiment of the present invention. Like the mixer 541 according to the sixth embodiment, the mixer 641 according to this embodiment includes a bearing unit 2 including a plurality of bearing elements, but the plurality of bearing elements are four bearing elements, namely, a first bearing element 2a, a second bearing element 2b, a third bearing element 2c, and a fourth bearing element 2d, which are arranged in this order from the side closest to the rotor body 52 in the rotor axial direction. A threaded hole 9 is formed at the axially inner end of each of the first to fourth bearing elements 2a to 2d, and each threaded hole 9 opens toward the rotor body 52 along the rotor axial direction.

[0054] Like the kneader 541 according to the sixth embodiment, the kneader 641 according to this embodiment includes a plurality of inner seal materials 4A and an outer seal material 4B, and the plurality of inner seal materials 4A are fitted into inner seal grooves 2f formed in the inner peripheral surfaces of the second and third bearing elements 2b and 2c, respectively. The inner seal material 4A fitted into the inner seal groove 2f of the second bearing element 2b includes a portion interposed between the second bearing element 2b and the third bearing element 2c in the rotor axial direction, and the inner seal material 4A fitted into the inner seal groove 2f of the third bearing element 2b includes a portion interposed between the third bearing element 2c and the fourth bearing element 2d in the rotor axial direction. On the other hand, the outer seal material 4B is fitted into an outer seal groove 2g formed in the second bearing element 2b.

[0055] Although not shown, it is preferable that adjacent bearing elements of the plurality of bearing elements 2a to 2d in the rotor axial direction have shapes that allow them to fit together. For example, the surface of the first bearing element 2a that faces the second bearing element 2b in the rotor axial direction may have a convex portion that protrudes in the rotor axial direction toward the second bearing element 2b, and the second bearing element 2b may have a concave portion that receives the convex portion. Conversely, the second bearing element 2b may have the convex portion, and the first bearing element 2a may have the concave portion. In this case, it is preferable that the inner seal groove 2f for receiving the inner seal material 4A be formed at a position in the rotor axial direction that is separated from the end of the bearing element where the convex portion or the concave portion is formed, as shown in FIG. 9, for example.

[0056] The kneader 641 further includes a sleeve 10 shown in FIG. 10. The sleeve 10 is disposed so as to be interposed between the inner circumferential surfaces of the plurality of bearing elements 2a to 2d and the outer circumferential surface 54a of the rotor shaft 54 ​​in the radial direction of the bearing portion 2. The sleeve 10 includes a sleeve main body 10a and a sleeve protrusion 10b. The sleeve main body 10a has a cylindrical shape extending in the rotor axial direction along the outer circumferential surface 54a of the rotor shaft 54. The sleeve protrusion 10b is formed at one of both end portions of the sleeve main body 10a in the rotor axial direction that is farther from the rotor main body 52, and protrudes radially outward beyond the outer circumferential surface of the other portion. With the plurality of bearing elements 2a to 2d and the sleeve 10 inserted into the bearing accommodating space S2 of the bearing support portion 3b, a gap 14 in the rotor axial direction is formed between the sleeve protruding portion 10b and the bearing element farthest from the rotor main body 52 among the plurality of bearing elements 2a to 2d, i.e., the fourth bearing element 2d. Specifically, a recess 2r for ensuring the gap 14 is formed in one of both ends of the fourth bearing element 2d in the rotor axial direction, the end closer to the sleeve protruding portion 10b.

[0057] The sleeve 10 can be extracted in the rotor axial direction into the kneading space together with the first to fourth bearing elements 2a to 2d in a state in which the rotor body 52 is separated from the rotor shaft 54. In other words, extracting the sleeve 10 in the rotor axial direction makes it possible to extract the plurality of bearing elements 2a to 2d together with the sleeve 10 from between the inner circumferential surface 3n of the bearing support portion 3b and the outer circumferential surface 54a of the rotor shaft 54. This makes it possible to extract the entire bearing portion 2 in a shorter time than the process of extracting the plurality of bearing elements 2a to 2d one by one.

[0058] The sleeve 10 does not necessarily have to be extracted together with all of the plurality of bearing elements 2 a to 2 d. For example, it is possible to extract only the bearing element of the plurality of bearing elements 2 a to 2 d that is closest to the rotor body 52, i.e., the first bearing element 2 a, using a pulling tool such as a bolt, and then grasp the outer circumferential surface of the sleeve 10 exposed thereby to extract the sleeve 10 and the remaining bearing elements, i.e., the second to fourth bearing elements 2 b to 2 d, all together.

[0059] The inner seal material 4A according to the present embodiment seals the gap between the outer peripheral surface of the sleeve 10 and the inner peripheral surface of the bearing portion 2. In this way, the gap sealed by the inner seal material 4A and present between the inner peripheral surface 2n of the bearing portion 2 and the outer peripheral surface 54a of the rotor shaft 54 ​​is not limited to the gap formed between the inner peripheral surface 2n of the bearing portion 2 and the outer peripheral surface 54a of the rotor shaft 54, for example, as shown in Fig. 3 , but also includes a gap formed between the outer peripheral surface of the sleeve 10 and the inner peripheral surface of the bearing portion 2 at a position radially outward of the outer peripheral surface 54a of the rotor shaft 54, as shown in Fig. 10 .

[0060] The rotor shaft 54 ​​preferably has a rotor shaft protruding portion 54b that faces one of the two ends of the bearing portion 2 in the rotor axial direction that is farther from the rotor main body 52. ​​The rotor shaft protruding portion 54b makes it possible to extract the entire bearing portion 2, including the plurality of bearing elements 2a to 2d and the sleeve 10, together with the rotor shaft 54, by extracting the rotor shaft 54 ​​from the bearing support portion 3b into the kneading space in the rotor axial direction (to the right in FIG. 10).

[0061] The inner circumferential surface of the first bearing element 2a, which is the bearing element closest to the rotor body 52 among the plurality of bearing elements 2a to 2d, and the outer circumferential surface of the sleeve body 10a may have a shape that threads together. For example, a female thread portion may be formed on the inner circumferential surface of the first bearing element 2a, and a male thread portion that can threadably engage with the female thread portion may be formed on the outer circumferential surface of the sleeve body 10a. This makes it possible to pull the first bearing element 2a into the kneading space using a pulling tool or the like, thereby extracting the remaining bearing elements 2b to 2d and the sleeve 10 all at once. In this case, the sleeve 10 and the first bearing element 2a may rotate together with the rotor shaft 54 ​​as the rotor 5 rotates.

[0062] Alternatively, the sleeve 10 may be extracted after the bearing elements 2a to 2d have been extracted one by one.

[0063] The sleeve protrusion 10b more reliably extracts the bearing elements 2a to 2d together with the sleeve 10 from between the inner circumferential surface 3n of the bearing support 3b and the outer circumferential surface 54a of the rotor shaft 54. Furthermore, the gap 14 in the rotor axial direction, i.e., the gap 14 formed between the fourth bearing element 2d and the sleeve protrusion 10b when the bearing elements 2a to 2d and the sleeve 10 are inserted between the inner circumferential surface 3n of the bearing support 3b and the outer circumferential surface 54a of the rotor shaft 54, makes it possible to prevent seizure from occurring during rotation of the rotor 5. Specifically, the sleeve 10 may rotate together with the rotor shaft 54 ​​when the rotor 5 rotates, but because the bearing elements 2a to 2d are supported by the bearing support 3, the rotation of the rotor 5 may involve relative rotation between the sleeve 10 and the bearing elements 2a to 2d. On the other hand, if the pressure of the working fluid in the chamber 3 is high, the pressure of the working fluid may push the plurality of bearing elements 2a to 2d toward the opposite side of the rotor body 52 in the rotor axial direction. In this case, the gap 14 prevents the fourth bearing element 2d from being pressed against the sleeve protrusion 10b in the rotor axial direction, thereby preventing relative rotation between the plurality of bearing elements 2a to 2d and the sleeve 10 from causing seizure between the fourth bearing element 2d and the sleeve protrusion 10b.

[0064] The kneader 641 according to this embodiment further includes a sleeve seal 11 that seals between the outer peripheral surface 54a of the rotor shaft 54 ​​and the inner peripheral surface 10n of the sleeve 10. The sleeve seal 11 is, for example, an O-ring, and is attached to the outer peripheral surface 54a of the rotor shaft 54. Specifically, an annular seal groove 54f is formed in the outer peripheral surface 54a of the rotor shaft 54, and the sleeve seal 11 is fitted into the seal groove 54f.

[0065] The kneader 641 further includes a rotation prevention member for preventing rotation of the bearing 2 relative to the bearing support 3b. Specifically, the kneader 641 includes a first rotation prevention member 12A and a second rotation prevention member 12B as illustrated in FIG. 10. The first rotation prevention member 12A penetrates the bearing support 3b in the radial direction from the outer surface of the bearing support 3b to the bearing accommodating space S2, and the radially inner end of the first rotation prevention member 12A engages with a target bearing element selected from the plurality of bearing elements 2a to 2d, i.e., the second bearing element 2b in FIG. 10. Similarly, the second rotation prevention member 12B penetrates the bearing support 3b in the radial direction from the outer surface of the bearing support 3b to the bearing accommodating space S2, and the radially inner end of the second rotation prevention member 12B engages with a target bearing element selected from the plurality of bearing elements 2a to 2d, i.e., the third bearing element 2c in FIG. 10.

[0066] The first and second anti-rotation members 12A, 12B prevent the second and third bearing elements 2b, 2c, which are the target bearing elements, from rotating around the rotor shaft 54 ​​relative to the bearing support portion 3b, thereby preventing the second and third bearing elements 2b, 2c from rotating together with the rotor shaft 54 ​​as the rotor 5 rotates.

[0067] As described above, the structure in which two axially adjacent bearing elements fit together makes it possible to suppress rotation of the target bearing element by preventing rotation of the target bearing element, thereby also suppressing rotation of the bearing element that fits with the target bearing element. This makes it possible to reduce the number of anti-rotation members required to prevent rotation of each of the multiple bearing elements 2 a to 2 d. For example, the structure in which the first bearing element 2 a and the second bearing element 2 b shown in FIG. 10 fit together makes it possible for the second anti-rotation member 12A to prevent rotation of the second bearing element 2 b, thereby also suppressing rotation of the first bearing element 2 a.

[0068] As shown in FIG. 11 as a modified example of the kneader 641, the kneader 641 may further include a Viscoseal 15. The Viscoseal 15 is disposed between the outer peripheral surface of the sleeve 10 and the inner peripheral surface 3n of the bearing support portion 3b. The Viscoseal 15 is interposed between the first bearing element 2a and the rotor main body 52 in the rotor axial direction. Furthermore, a spacer 16 is interposed between the Viscoseal 15 and the first bearing element 2a. The Viscoseal 15 threads into the outer peripheral surface of the sleeve main body 10a. Specifically, a male thread portion 17a is formed on the outer peripheral surface of the sleeve main body 10a, and a female thread portion 17b that threads into the male thread portion 17a is formed on the inner peripheral surface of the Viscoseal 15. This threaded engagement causes the sleeve 10 and the Viscoseal 15 to rotate together with the rotor shaft 54 ​​as the rotor 52 rotates. In addition, the threaded engagement allows the plurality of bearing elements 2a to 2d and the sleeve 10 to be pulled together from between the outer peripheral surface 54a of the rotor shaft 54 ​​and the inner peripheral surface 3n of the bearing support portion 3b by pulling the viscoseal 15 toward the kneading space.

[0069] 12 shows a mixer 741 according to an eighth embodiment of the present invention. Similar to the mixer 641 according to the seventh embodiment, the mixer 741 according to this embodiment also includes a bearing unit 2 including a plurality of bearing elements arranged in the rotor axial direction, the bearing elements being a first bearing element 2a, a second bearing element 2b, a third bearing element 2c, and a fourth bearing element 2d. A threaded hole 9 is formed in the axially inner end of each of the first to third bearing elements 2a to 2c. The mixer 741 further includes a plurality of inner seals 4A that seal the gap between the outer peripheral surface of the sleeve 10 and the inner peripheral surface of the bearing unit 2, and an outer seal 4B that seals the gap between the outer peripheral surface of the bearing unit 2 and the inner peripheral surface 3n of the bearing support portion 3b. The plurality of inner seals 4A include an inner seal 4A that is fitted into an inner seal groove 2f formed in the second bearing element 2b and includes a portion interposed between the second bearing element 2b and the third bearing element 2c, and an inner seal 4A that is fitted into an inner seal groove 2f formed in the third bearing element 2c and includes a portion interposed between the third bearing element 2c and the fourth bearing element 2d. The outer seal 4B is, for example, an O-ring, and is attached to the outer peripheral surface of the second bearing element 2b.

[0070] Similar to the bearing portion 2 according to the seventh embodiment, the bearing portion 2 further includes the sleeve 10 and a sleeve sealant 11. The sleeve 10 is interposed radially of the bearing portion 2 between inner circumferential surfaces of the first to fourth bearing elements 2a to 2d and the outer circumferential surface of the rotor shaft 54. The sleeve 10 includes a cylindrical sleeve main body 10a and a sleeve protrusion 10b, and the sleeve sealant 11 is fitted into a seal groove 54f formed in the outer circumferential surface 54a of the rotor shaft 54 ​​to provide a seal between the inner circumferential surface 10n of the sleeve 10 and the outer circumferential surface 54a of the rotor shaft 54.

[0071] The kneader 741 according to the eighth embodiment further includes an inner pile seal 18 (see FIG. 12). The inner pile seal 18 protects the inner seal 4A from foreign matter in the material being kneaded. For example, if a powder material containing nanomaterials such as silica or carbon is kneaded in the kneading space S1 (see FIG. 2), the powder material may enter the bearing housing space S2 and damage the inner seal 4A or the outer seal 4B, thereby reducing the sealing performance of the seals 4A and 4B. In particular, because the inner circumferential surface of the bearing portion 2 is in sliding contact with the outer circumferential surface of the sleeve body 10a in the circumferential direction, the size of the gap between the inner circumferential surface of the bearing portion 2 and the outer circumferential surface 54a of the rotor shaft 54 ​​is likely to vary in the axial direction, making it easy for the powder material to enter the gap. The inner pile seal 18 prevents powder material from entering the gap from the kneading space and reaching the inner seal 4A.

[0072] Specifically, the inner pile seal 18 is positioned closer to the kneading space in the rotor axial direction than the inner seal material 4A, so as to seal the gap between the inner circumferential surface of the bearing portion 2 and the outer circumferential surface 54a of the rotor shaft 54 ​​(in the eighth embodiment, the gap between the inner circumferential surface of the bearing portion 2 and the outer circumferential surface of the sleeve body 10a). In the kneader 741 illustrated in FIG. 12 , an annular inner pile seal groove 2p is formed on the inner circumferential surface of the first bearing element 2a, which is positioned closer to the kneading space than the inner seal material 4A, and the inner pile seal 18 is fitted into the pile seal groove 2p. The inner pile seal 18 includes a base fabric and a plurality of fibrous cut pile yarns woven into the base fabric. The base fabric is formed into an annular shape and fitted into the inner pile seal groove 2p. The cut pile yarns are raised from the base fabric toward the outer peripheral surface 54a of the rotor shaft 54, thereby sealing the gap between the inner peripheral surface of the first bearing element 2a and the outer peripheral surface of the sleeve body 10a. Specifically, in the eighth embodiment, the tip portions of the cut pile yarns of the inner pile seal 18 are pressed against the outer peripheral surface of the sleeve body 10a, thereby preventing powder material that has entered the gap between the inner peripheral surface of the bearing portion 2 and the outer peripheral surface of the sleeve 10 from reaching the inner sealing material 4A.

[0073] In this way, even if powder material enters the gap between the inner surface of the bearing portion 2 and the outer surface 54a of the rotor shaft 54, or in Figure 12, the gap between the inner surface of the bearing portion 2 and the outer surface of the sleeve body 10a, the inner pile seal 18 reduces the possibility of the powder material passing over the inner pile seal 18 and reaching the inner sealing material 4A, thereby preventing the powder material from damaging the inner sealing material 4A and reducing the sealing properties of the inner sealing material 4A.

[0074] 13 as a modification of the eighth embodiment, the kneader 741 preferably further includes an outer pile seal 19. The outer pile seal 19 is provided to prevent the powder material from reaching the outer sealing material 5.

[0075] Specifically, the outer pile seal 19 is disposed at a position closer to the kneading space in the rotor axial direction than the outer seal material 4B, so as to seal the gap between the outer peripheral surface of the bearing portion 2 and the inner peripheral surface 3n of the bearing support portion 3b surrounding the bearing accommodating space S2. In the kneader 741 illustrated in Figure 13, an annular outer pile seal groove 2q is formed on the outer peripheral surface of the first bearing element 2a, which is located closer to the kneading space than the outer seal material 4B, and the outer pile seal 19 is fitted into the outer pile seal groove 2q. Like the inner pile seal 18, the outer pile seal 19 includes a base fabric and a large number of fibrous cut pile yarns, and the base fabric is formed in an annular shape and fitted into the outer pile seal groove 2q. The cut pile yarn is raised from the base fabric toward the inner peripheral surface 3n of the bearing support portion 3b, thereby sealing the gap between the outer peripheral surface of the first bearing element 2a and the inner peripheral surface 3n of the bearing support portion 3b. Specifically, in the eighth embodiment, the tip portion of the cut pile yarn of the outer pile seal 19 is pressed against the inner peripheral surface 3n of the bearing support portion 3b, thereby preventing powder material that has entered the gap between the outer peripheral surface of the bearing portion 2a and the inner peripheral surface 3n of the bearing support portion 3b from reaching the outer sealing material 5.

[0076] The materials constituting the inner pile seal 18 and the outer pile seal 19 preferably have an SP value capable of suppressing swelling of the inner pile seal 18 and the outer pile seal 19 due to contact with the working fluid. The SP value (Hildebrand solubility parameter: δ) is a physical property defined as the square root of the cohesive energy density and is a numerical value that indicates the solubility behavior of a solvent. The smaller the difference between the SP values ​​of the inner pile seal 18 and the outer pile seal 19 and the SP value of the working fluid, the more likely the swelling will occur, and the swelling will promote a decrease in the sealing ability and durability of the inner pile seal 18 and the outer pile seal 19.

[0077] Specifically, the working fluid is supercritical CO ２ If CO ２The SP value of the material constituting the inner pile seal 18 and the material constituting the outer pile seal 19 is 8.7. ２ It is preferable that the difference between the SP value of the supercritical CO 2 as the working fluid and the SP value of the supercritical CO 2 as the working fluid is more than 0.7, that is, less than 8.0 or more than 9.4. ２ Regardless of the use of the inner pile seal 18 and the outer pile seal 19, it is possible to effectively prevent deterioration in the sealing properties and durability of each of the inner pile seal 18 and the outer pile seal 19.

[0078] In this way, even if the powder material gets into the gap between the inner circumferential surface of the bearing portion 2 and the inner circumferential surface 3n of the bearing support portion 3b, the outer pile seal 19 reduces the possibility of the powder material passing over the outer pile seal 19 and reaching the outer seal material 4B, thereby preventing the powder material from damaging the outer seal material 4B and reducing the sealing ability of the outer seal material 4B. The outer pile seal 19 does not necessarily have to be used together with the inner pile seal 18. For example, the inner pile seal 18 may be omitted in the kneader 741 shown in FIG. 13.

[0079] The effects provided by the mixers according to the above-described embodiments become even clearer when compared with a mixer 941 shown as a reference example in Fig. 14. The mixer 941 includes a rotor 95 including a rotor body 952 and a rotor shaft 954, a chamber 93 including a chamber body and a bearing support portion 93b, and a plurality of seals 94A and 94B. Each of the plurality of seals 94A and 94B is a one-sided pressure seal with a built-in spring, and seals between the outer peripheral surface of the rotor shaft 954 and the inner peripheral surface of the bearing support portion 93b. The bearing support portion 93b is composed of a plurality of members 96A, 96B, 96C, 96D, 96E, and 96F arranged in the rotor axial direction. The sealing material 94A is sandwiched between the members 96B and 96D in the rotor axial direction and fixed at a position radially inward of the member 96C, and the sealing material 94B is sandwiched between the members 96D and 96F in the rotor axial direction and fixed at a position radially inward of the member 96E.

[0080] In order to replace the first and second seal materials 94A, 94B in the kneader 941, it is necessary to remove the rotor 95 from the chamber 93 and disassemble the chamber 93, which is a cumbersome task. In contrast, in the kneader in each of the above embodiments, maintenance of the seal materials 4A, 4B can be easily performed by separating the rotor body 52 from the rotor shaft 54 ​​and extracting the bearing portion 2 from between the inner peripheral surface 3 n of the bearing support portion 3 b and the outer peripheral surface 54 a of the rotor shaft 54.

[0081] Although the embodiments of the present invention have been described above, they are merely illustrative examples and do not limit the present invention, and the specific configurations and other aspects can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferred actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention.

[0082] For example, the rotation prevention members 12A, 12B according to the seventh embodiment can be applied to any of the first to sixth and eighth embodiments.

[0083] In each of the sixth to eighth embodiments, as a means for facilitating removal of the bearing portion 2, any of the protrusion 6 according to the second embodiment, the male threaded portion 7a and the female threaded portion 7b according to the third embodiment, and the magnetic portion 8 according to the fourth embodiment may be provided at the end of the bearing portion 2 instead of the screw hole 9.

[0084] Each of the inner pile seal 18 and the outer pile seal 19 can be applied to any of the first to seventh embodiments. For example, even in a mixer that does not include the sleeve 10, such as the mixer 41 according to the first embodiment, the inner pile seal 18 can be disposed so as to seal the gap between the inner peripheral surface 2n of the bearing portion 2 and the outer peripheral surface 54a of the rotor shaft 54.

[0085] As described above, a kneading machine capable of easily performing maintenance on its sealing material is provided. The kneading machine kneads materials in the presence of a working fluid in a supercritical or subcritical state. The kneading machine includes a chamber, a rotor, a bearing unit, an inner seal, and an outer seal. The chamber includes a chamber body defining a kneading space and a bearing support unit defining a bearing accommodating space, the kneading space and the bearing accommodating space being interconnected. The rotor includes a rotor shaft and a rotor body separably connected in the rotor axial direction, the rotor shaft being disposed in the bearing accommodating space, and the rotor body kneads the materials in the kneading space. The bearing unit is disposed in the bearing accommodating space between the inner circumferential surface of the bearing support unit and the outer circumferential surface of the rotor shaft so as to be detachable from the bearing support unit and the rotor shaft, and rotatably supports the rotor shaft while being supported by the bearing support unit. The inner seal material seals a gap between an inner peripheral surface of the bearing portion and the outer peripheral surface of the rotor shaft. The outer seal material seals a gap between the outer peripheral surface of the bearing portion and the inner peripheral surface of the bearing support portion. The bearing portion is arranged such that, when the rotor body is separated from the rotor shaft, the bearing portion can be extracted from between the inner peripheral surface of the bearing support portion and the outer peripheral surface of the rotor shaft in the axial direction of the rotor and inserted from the kneading space into between the bearing support portion and the rotor shaft in the axial direction of the rotor.

[0086] In the kneading machine, maintenance, such as replacement, of the inner seal and the outer seal can be easily performed by simply separating the rotor body from the rotor shaft and extracting the bearing from between the inner circumferential surface of the bearing support and the outer circumferential surface of the rotor shaft. Furthermore, it is not necessary to remove the rotor shaft from the chamber for maintenance of the inner seal or the outer seal, which makes it possible to reduce the space required around the kneading machine for removing the rotor shaft.

[0087] Preferably, the bearing includes a bearing body accommodated in the bearing accommodating space and a protruding portion located closer to the rotor body in the rotor axial direction than the bearing body and having a thickness in the radial direction of the bearing portion greater than that of the bearing body, and the protruding portion protrudes in the rotor axial direction toward the rotor body beyond the bearing support portion when the bearing body is inserted between the bearing support portion and the rotor shaft. The protruding portion makes it easy to remove the bearing from between the outer circumferential surface of the rotor shaft and the inner circumferential surface of the bearing support portion.

[0088] The bearing portion may include a male thread portion, and the bearing support portion may include a female thread portion that can be threadedly engaged with the male thread portion. The male thread portion is formed on the outer peripheral surface of one of both end portions of the bearing portion in the rotor axial direction that is closer to the rotor body. The female thread portion is formed on the inner peripheral surface of the bearing support portion that surrounds the bearing accommodating space, and is threadedly engaged with the male thread portion to fix the bearing portion within the bearing accommodating space, thereby preventing the bearing portion from rotating with the rotor shaft.

[0089] The bearing portion may include a magnetic portion. The magnetic portion is magnetic and is provided at one of both ends of the bearing portion in the rotor axial direction that is closer to the rotor main body. The magnetic portion enables the magnetic portion to be attracted by a magnet. Specifically, the magnetism of the magnetic portion has a strength that enables the magnetic portion to be attracted to a magnet and pulled out from between the inner circumferential surface of the bearing support portion and the outer circumferential surface of the rotor shaft when the rotor main body is separated from the rotor shaft, thereby making it easy to remove the bearing portion from between the outer circumferential surface of the rotor shaft and the inner circumferential surface of the bearing support portion.

[0090] The bearing portion may have a threaded hole formed in one of both ends of the bearing portion in the rotor axial direction that is closer to the rotor body and that opens in the rotor axial direction toward the rotor body, thereby enabling a pulling tool for pulling the bearing portion to be threadedly engaged with the threaded hole and connected to the bearing portion.

[0091] The bearing portion may include a plurality of bearing elements that are arranged in the rotor axial direction to rotatably support the rotor shaft. This allows the bearing portion to be removed from between the outer circumferential surface of the rotor shaft and the inner circumferential surface of the bearing support portion on a bearing element-by-bearing element basis, and to be inserted between the outer circumferential surface of the rotor shaft and the inner circumferential surface of the bearing support portion on a bearing element-by-bearing element basis.

[0092] In this case, the rotor shaft may further include a sleeve interposed between the plurality of bearing elements and the outer peripheral surface of the rotor shaft in the radial direction of the bearing portion, wherein the sleeve allows the plurality of bearing elements arranged around the sleeve to be extracted from between the inner peripheral surface of the bearing support portion and the outer peripheral surface of the rotor shaft when the rotor body is separated from the rotor shaft.

[0093] Preferably, the sleeve includes a sleeve main body extending in the rotor axial direction along the outer circumferential surface of the rotor shaft, and a sleeve protrusion protruding radially outward from one of both ends of the sleeve main body in the rotor axial direction opposite the rotor main body. The sleeve protrusion enables the multiple bearing elements to be more reliably removed together with the sleeve. Here, when the multiple bearing elements and the sleeve are inserted into the bearing accommodating space, a gap in the rotor axial direction is preferably formed between the sleeve protrusion and the bearing element farthest from the rotor main body, and the sleeve protrusion. The gap suppresses seizure between the sleeve protrusion and the bearing elements as the rotor rotates.

[0094] The kneader further includes an inner pile seal that seals a gap between the inner peripheral surface of the bearing portion and the outer peripheral surface of the rotor shaft, and the inner pile seal is preferably located closer to the rotor body in the axial direction of the rotor than the inner sealing material. The inner pile seal prevents foreign matter that has entered the gap from the kneading space from reaching the inner sealing material, thereby preventing the sealing performance of the inner sealing material from being reduced by the foreign matter.

[0095] The kneader further includes an outer pile seal that seals a gap between the outer peripheral surface of the bearing portion and the inner peripheral surface of the bearing support portion that surrounds the bearing accommodating space, and the outer pile seal is preferably located closer to the rotor body in the rotor axial direction than the outer sealing material. The outer pile seal prevents foreign matter that has entered the gap from the kneading space from reaching the outer sealing material, thereby preventing the sealing performance of the outer sealing material from being reduced by the foreign matter.

[0096] The working fluid is supercritical CO ２ In this case, the material constituting the inner pile seal preferably has an SP value of less than 8.0 or more than 9.4. This increases the difference between the SP value of the working fluid (8.7) and the SP value of the inner pile seal, thereby suppressing swelling of the inner pile seal due to contact with the working fluid and effectively preventing deterioration of the sealing ability and durability of the inner pile seal due to the swelling.

[0097] Similarly, the working fluid is supercritical CO ２ In this case, the material constituting the outer pile seal preferably has an SP value of less than 8.0 or more than 9.4. This increases the difference between the SP value of the working fluid (8.7) and the SP value of the outer pile seal, thereby suppressing swelling of the outer pile seal due to contact with the working fluid and effectively preventing deterioration of the sealing ability and durability of the outer pile seal due to the swelling.

[0098] The kneader may further include a rotation prevention member that prevents the bearing from rotating about the rotor shaft relative to the bearing support. Preventing rotation of the bearing by the rotation prevention member further ensures that the bearing supports the rotor shaft rotatably.

[0099] When the bearing portion includes a plurality of bearing elements that are arranged in the rotor axial direction and rotatably support the rotor shaft, it is preferable that the anti-rotation member is arranged to prevent rotation of a target bearing element selected from the plurality of bearing elements, and the target bearing element and the bearing element adjacent to the target bearing element in the rotor axial direction have shapes that fit together to suppress relative rotation between them. This makes it possible for the anti-rotation member to prevent rotation of the target bearing element, thereby also suppressing rotation of the bearing element that fits with the target bearing element.

Claims

1. A kneader for kneading materials in the presence of a working fluid in a supercritical or subcritical state, comprising: a chamber including a chamber body defining a kneading space and a bearing support part defining a bearing accommodating space, the kneading space and the bearing accommodating space communicating with each other; a rotor including a rotor shaft and a rotor body interconnected in the rotor axial direction so as to be separable from each other, the rotor shaft being disposed in the bearing accommodating space and the rotor body being configured to knead the material in the kneading space; a bearing part disposed in the bearing accommodating space between an inner peripheral surface of the bearing support part and an outer peripheral surface of the rotor shaft so as to be detachable from the bearing support part and the rotor shaft, the bearing part rotatably supporting the rotor shaft while being supported by the bearing support part; an inner seal material for sealing a gap between the inner peripheral surface of the bearing part and the outer peripheral surface of the rotor shaft; and an outer seal material for sealing a gap between the outer peripheral surface of the bearing part and the inner peripheral surface of the bearing support part, A kneader in which the bearing portion is positioned so that, upon separation of the rotor body from the rotor shaft, the bearing portion can be extracted from between the inner circumferential surface of the bearing support portion and the outer circumferential surface of the rotor shaft into the kneading space in the axial direction of the rotor, and the bearing portion can be inserted from the kneading space between the bearing support portion and the rotor shaft in the axial direction of the rotor.

2. A kneading machine as described in claim 1, wherein the bearing portion includes a bearing main body portion accommodated in the bearing accommodating space, and a protruding portion located closer to the rotor body in the rotor axial direction than the bearing main body portion and having a thickness greater in the radial direction of the bearing portion than the thickness of the bearing main body portion, and the protruding portion protrudes in the rotor axial direction toward the rotor body beyond the bearing support portion when the bearing main body portion is inserted between the bearing support portion and the rotor shaft.

3. A kneading machine as described in claim 1, wherein the bearing portion includes a male threaded portion which is formed on the outer peripheral surface of the end of the bearing portion closest to the rotor body in the rotor axial direction, and the bearing support portion includes a female threaded portion which can be screwed into the male threaded portion, and the female threaded portion is formed on the inner peripheral surface of the bearing support portion which surrounds the bearing accommodating space, and the bearing portion is fixed within the bearing accommodating space by screwing into the male threaded portion.

4. A kneader as described in claim 1, wherein the bearing portion includes a magnetic portion, which is provided at one of the two ends of the bearing portion in the rotor axial direction that is closer to the rotor body, and which has magnetism that enables the magnetic portion to be attracted to a magnet.

5. A kneader as described in claim 1, wherein the bearing portion has a threaded hole, the threaded hole being formed at one of the two ends of the bearing portion in the rotor axial direction that is closer to the rotor body, and opening in the rotor axial direction toward the rotor body.

6. A kneader according to any one of claims 1 to 5, wherein the bearing portion includes a plurality of bearing elements, the plurality of bearing elements being arranged in line in the axial direction of the rotor to rotatably support the rotor shaft.

7. A kneading machine as claimed in claim 6, further comprising a sleeve interposed between said plurality of bearing elements and said outer peripheral surface of said rotor shaft in the radial direction of said bearing portion, said sleeve being capable of being removed from between the inner peripheral surface of said bearing support portion and the outer peripheral surface of said rotor shaft together with said plurality of bearing elements arranged around said sleeve when said rotor body is separated from said rotor shaft.

8. A kneading machine as described in claim 7, wherein the sleeve includes a sleeve main body extending in the rotor axial direction along the outer circumferential surface of the rotor shaft, and a sleeve protrusion protruding radially outward from the end of the sleeve main body opposite the rotor body, of both ends in the rotor axial direction, and when the multiple bearing elements and the sleeve are inserted into the bearing accommodating space, a gap in the rotor axial direction is formed between the bearing element farthest from the rotor body among the multiple bearing elements and the sleeve protrusion.

9. A kneader as claimed in claim 1, further comprising an inner pile seal for sealing a gap between the inner peripheral surface of the bearing portion and the outer peripheral surface of the rotor shaft, the inner pile seal being located closer to the rotor body in the axial direction of the rotor than the inner sealing material.

10. The kneader according to claim 9, wherein the working fluid is supercritical CO ２ and the material constituting the inner pile seal has an SP value of less than 8.0 or more than 9.

4.

11. A kneader as claimed in claim 1, further comprising an outer pile seal for sealing a gap between the outer peripheral surface of said bearing portion and the inner peripheral surface of said bearing support portion surrounding said bearing accommodating space, said outer pile seal being located closer to said rotor body in the rotor axial direction than said outer sealing material.

12. The kneader according to claim 11, wherein the working fluid is supercritical CO ２ and the material constituting the outer pile seal has an SP value of less than 8.0 or more than 9.

4.

13. A kneader according to any one of claims 1 to 5, further comprising a rotation prevention member that prevents the bearing portion from rotating about the rotor shaft relative to the fixed portion.

14. A kneading machine as described in claim 13, wherein the bearing portion includes a plurality of bearing elements, the plurality of bearing elements are arranged in a line in the rotor axial direction to rotatably support the rotor shaft, the rotation prevention member is arranged to prevent rotation of a target bearing element selected from the plurality of bearing elements, and the target bearing element and a bearing element adjacent to the target bearing element in the rotor axial direction have shapes that fit together to suppress relative rotation with each other.

Images