Closed kneader

Abstract

To provide a closed kneader that can stably keep an oil film thickness of lubricating oil supplied to a leakage prevention part between a rotor shaft part of a kneading rotor and a chamber.SOLUTION: A leakage prevention part 100 of a kneader 1 includes: a fixed side seal 10 attached to a casing so as to surround a rotor shaft part of a kneading rotor; a rotation side seal 9 attached to the rotor shaft part so as to face the fixed side seal 10, and capable of rotating while sliding with respect to the fixed side seal 10; and a lubricating oil supply mechanism 50 for supplying lubricating oil to a sliding part between the fixed side seal 10 and the rotation side seal 9. The lubricating oil supply mechanism 50 periodically repeats a supply operation and a stop operation for the lubricating so as to intermittently supply the lubricating oil to the sliding part.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an internal mixer. [Background technology]

[0002] Conventionally, there is known an internal mixer that mixes materials such as rubber and plastics with various additives. Patent Document 1 discloses such an internal mixer having a chamber and a pair of kneading rotors. The chamber forms a kneading chamber, and the pair of kneading rotors are arranged side by side in the kneading chamber and rotate. A shear force is applied to the material to be kneaded between the pair of kneading rotors and the chamber, and the material to be kneaded is kneaded.

[0003] In addition, in the technology described in Patent Document 1, a lubricant is supplied to a seal between a chamber and a rotor shaft of the kneading rotor, and a mechanism is provided to adjust the amount of lubricant supplied in accordance with the rotation speed of the kneading rotor. Specifically, the mechanism reduces the amount of lubricant supplied when the kneading rotor is operating at a low speed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6526439 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology described in Patent Document 1 is expected to have a certain effect when the kneading rotor is operated while changing its rotation speed, but in a steady state where the kneading rotor is operated at a constant speed, the amount of lubricating oil supplied cannot be reduced. In addition, when the kneading rotor rotation speed is set to a low speed, the rotation speed of the electric motor that controls the amount of lubricating oil supplied is reduced, which causes a problem that the oil film thickness of the lubricating oil becomes excessively small, which easily causes wear of surrounding members and leakage of the material to be kneaded.

[0006] An object of the present invention is to provide an internal mixer that can stably maintain the oil film thickness of the lubricating oil supplied to the leakage prevention section between the rotor shaft of the kneading rotor and the chamber while reducing the total amount of lubricating oil supplied to the sliding sections. [Means for solving the problem]

[0007] The internal mixer according to one aspect of the present invention includes a casing including a chamber for storing a material to be mixed therein, a mixing rotor including a rotor shaft extending to the outside of the chamber and a mixing blade disposed inside the chamber, and rotating to mix the material to be mixed in the chamber, and a leakage prevention unit for preventing the material to be mixed in the chamber from leaking out of the chamber. The leakage prevention unit includes a fixed side seal attached to the casing so as to surround the rotor shaft, a rotating side seal attached to the rotor shaft so as to face the fixed side seal and rotatable while sliding against the fixed side seal, and a lubricating oil supply mechanism for supplying lubricating oil to a sliding part between the fixed side seal and the rotating side seal, and the lubricating oil supply mechanism periodically repeats a supply operation and a stop operation of the lubricating oil so as to intermittently supply the lubricating oil to the sliding part.

[0008] According to this configuration, it is possible to reduce the total amount of lubricating oil supplied to the sliding parts while stably maintaining the oil film thickness necessary for lubrication. As a result, by reducing the amount of oil used, the impact on the environment due to waste oil is reduced, and it is also possible to reduce the running costs of the kneading machine.

[0009] In the above configuration, the lubricating oil supply mechanism may further include a pressing member that contacts the fixed side seal at a plurality of pressing points and presses the fixed side seal toward the rotating side seal, and the lubricating oil supply mechanism may have a plurality of oil inlets that supply lubricating oil to the sliding part near each of the plurality of pressing points.

[0010] According to this configuration, the sealing pressure between the fixed seal and the rotating seal is highest at the point pressed by the pressing member, and the sealing pressure is low at the point farthest from the pressing point in the direction of rotation. If an oil inlet were provided at a point where the sealing pressure was low, the oil pressure would open up a gap between the two seals, increasing the amount of oil that leaks out, resulting in a waste of lubricating oil. On the other hand, according to this configuration, the oil film thickness at the point pressed by the pressing member is relatively large, and oil film rupture can be effectively prevented, so that the sealing function of the leakage prevention part can be maintained even if the amount of lubricating oil supplied is reduced.

[0011] In the above configuration, the fixed side seal may have an annular groove on a surface facing the rotating side seal, and the depth of the groove may be set to vary along the rotational direction of the rotating side seal.

[0012] According to this configuration, the depth of the groove is set to vary along the direction of rotation, making it possible to partially change the pressure of the lubricating oil in the groove and to adjust the flow of the lubricating oil in the groove by the pressure difference.

[0013] In the above configuration, the oil inlet may be arranged upstream of the pressing point in the direction of rotation, and the depth of the groove may be set to become shallower as it approaches the pressing point from the oil inlet.

[0014] According to this configuration, the oil pooling effect of the groove and the wedge effect of the inclination provided in the groove can relatively increase the pressure near the pressing point, so that even if the amount of lubricating oil supplied is reduced, the oil film can be effectively prevented from breaking, and the sealing function of the leakage prevention part can be maintained. In particular, the lubricating oil that flows into the groove from the oil inlet is prevented from moving downstream in the rotation direction at the pressing point and flows back to the upstream in the rotation direction, so that the oil film around it can be thickened. Effect of the Invention

[0015] According to the present invention, it is possible to provide an internal mixer that can stably maintain the oil film thickness of the lubricating oil supplied to the leakage prevention section between the rotor shaft section of the kneading rotor and the chamber while reducing the total amount of lubricating oil supplied to the sliding sections. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a cross-sectional view of an internal mixer according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a front view showing a leakage prevention unit of the internal mixer according to one embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic perspective view showing an oil supply structure to a leakage prevention part of an internal mixer according to one embodiment of the present invention. [Figure 4] 4 is a graph showing the change in oil film thickness at a seal portion depending on the rotation speed of an oil supply mechanism of an internal mixer according to one embodiment of the present invention. [Diagram 5] 5 is an enlarged graph of a portion of the graph in FIG. 4. [Figure 6] 4 is a graph showing an average amount of oil fed in an oil feeding mechanism of an internal mixer according to one embodiment of the present invention. [Figure 7] 1 is a graph showing the relationship between the total amount of oil poured per hour and the oil film thickness in an internal mixer. [Figure 8] FIG. 13 is a schematic perspective view showing an oil supply structure to a leakage prevention portion of an internal mixer according to a modified embodiment of the present invention. [Figure 9] FIG. 9 is a plan view of the leak prevention part of FIG. 8. [Figure 10] 10 is a cross-sectional perspective view of the leak prevention portion of FIG. 9 taken along section XI-XI. [Figure 11] 10 is a cross-sectional view of the leakage prevention portion of FIG. 9 taken along section XI-XI. [Figure 12] 12 is a graph showing the distribution of groove depths of the stationary seal shown in FIGS. 10 and 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, a kneader 1 (closed kneader) according to one embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view of the kneader 1 according to this embodiment. Fig. 2 is a front view showing a leakage prevention unit 100 of the kneader 1. Fig. 3 is a schematic perspective view showing an oil supply structure to the leakage prevention unit 100 of the kneader 1. The structure and operation of the kneader 1 will be described below.

[0018] 1, the kneader 1 includes a pair of kneading rotors 2, a casing 3, a chamber 4, a ram 5, and a drop door 6. The chamber 4 is a space formed inside the casing 3.

[0019] The pair of kneading rotors 2 are rotated to knead the material to be kneaded, which is made of a polymeric material or the like, inside the chamber 4. Each kneading rotor 2 has a rotor shaft 2A and a kneading blade 2B. The rotor shaft 2A extends to the outside of the chamber 4 and is rotatably supported by the casing 3. The kneading blade 2B is disposed inside the chamber 4 and is a blade that protrudes radially outward from the rotor shaft 2A. The kneading blade 2B applies a shear force to the material to be kneaded by rotating.

[0020] The inner wall of the casing 3 is formed in a cocoon shape in the vertical cross section shown in Fig. 1, and end plates 8 are joined to both side surfaces of the casing 3 in the direction perpendicular to the paper surface of Fig. 1, as shown in Fig. 2. As a result, a chamber 4 including a pair of left and right kneading chambers 4a is formed so as to be able to accommodate the material to be kneaded therein.

[0021] An inlet 3a is formed in the upper center of the casing 3, through which the material to be kneaded, such as rubber or plastic, is fed into the chamber 4. A ram 5 is provided in the inlet 3a so as to be movable up and down, and presses the material to be kneaded fed into the chamber 4. Meanwhile, an outlet 3b is formed in the lower center of the chamber 4 so that the material to be kneaded that has reached a desired kneading state can be discharged to the outside, and a drop door 6 is provided for opening and closing the outlet 3b. The ram 5 and drop door 6 come into close contact with the casing 3 during kneading, thereby constituting part of the inner wall surface of the chamber 4.

[0022] 2 and 3, the kneader 1 further includes a leakage prevention unit 100. The leakage prevention unit 100 prevents the material to be kneaded, which is forced into the chamber 4 and kneaded, from the end of the kneading rotor 2 to the end of the kneading chamber 4a. It functions as a dust stop device to prevent dust from leaking out to the outside.

[0023] The leakage prevention unit 100 includes a rotating-side seal member 9, a fixed-side seal member 10, a plurality of cooling water pipes 16, a plurality of lubricating oil pipes 18, a yoke 20, a pair of yoke pins 21, a yoke stud 22, and a hydraulic cylinder 23. Furthermore, the kneader 1 includes a lubricating oil supply mechanism 50 that supplies lubricating oil to the leakage prevention unit 100 (FIG. 3).

[0024] The fixed side seal member 10 has a ring shape and is attached to the casing 3 so as to surround the rotor shaft portion 2A. The rotating side seal member 9 has a ring shape and is attached to the rotor shaft portion 2A so as to face the fixed side seal member 10. The rotating side seal member 9 is rotatable integrally with the rotor shaft portion 2A while sliding relative to the fixed side seal member 10. In other words, the rotating side seal member 9 rotates, whereas the fixed side seal member 10 does not rotate. The rotating side seal member 9 and the fixed side seal member 10 have ring-shaped opposing surfaces (surfaces, seal surfaces) that face each other. A seal portion is formed between these opposing surfaces to prevent leakage of the dust.

[0025] The fixed-side seal member 10 is fitted in a liquid-tight manner to the end plate 8 via a seal ring (not shown) on the kneading rotor 2 side so as to prevent leakage of the material to be kneaded or the lubricating oil to the outside. As shown in Fig. 2, a cooling water pipe 16 and a lubricating oil pipe 18 are connected to the end plate 8, and the fixed-side seal member 10 is cooled by flowing cooling water into the cooling water pipe 16. Meanwhile, the lubricating oil is supplied between the fixed-side seal member 10 and the rotating-side seal member 9 by flowing the lubricating oil into each lubricating oil pipe 18 from a lubricating oil supply mechanism 50 shown in Fig. 3.

[0026] Here, each sliding surface of the rotating seal member 9 and the fixed seal member 10 is formed of, for example, a hard-cladding metal. Note that materials that can be used for these sliding surfaces include various steels and copper alloys, as well as non-oil-impregnated materials such as ceramics and sintered carbon, and oil-impregnated metals such as gunmetal, cast iron, and sintered metals.

[0027] The yoke 20 is a plate material for transmitting the operating force of the hydraulic cylinder 23 to the fixed-side seal member 10, with the hydraulic cylinder 23 attached to one end and a yoke pin 21 attached to each of the other bifurcated ends. A yoke stud 22 is inserted into the bifurcated portion of the yoke 20 (approximately the center portion of the yoke 20), and the yoke 20 swings around this yoke stud 22 as a fulcrum. The yoke stud 22 is fixed to the end plate 8, and the yoke 20 is supported by the end plate 8 at the yoke stud 22. The tips of the two yoke pins 21 are fitted into holes formed in the end face of the fixed-side seal member 10 on the outer side of the rotor shaft portion 2A.

[0028] The fixed seal member 10 is prevented from rotating by yoke pins 21 attached to the two bifurcated ends of the yoke 20. The yoke pins 21 are pressed against the fixed seal member 10 via the yoke 20 by a hydraulic cylinder 23, thereby more reliably preventing the fixed seal member 10 from rotating.

[0029] The hydraulic cylinder 23 is a linear actuator that has a cylinder body and a piston rod, and the piston rod moves linearly when hydraulic oil is supplied to and discharged from the inside of the cylinder. Note that the linear actuator refers to an actuator that moves linearly, and is not limited to the hydraulic cylinder 23. Also, the actuation source of the linear actuator is not limited to hydraulic pressure, and may be other liquids, or a pneumatic cylinder may be used.

[0030] With reference to FIG. 3, the lubricating oil supply mechanism 50 includes a motor 51, an oil supply mechanism 52, a lubricating oil tank 53, an oil amount adjusting mechanism 54, and a controller 60.

[0031] The oil supply mechanism 52 has a crankshaft 52A and three discharge cylinders 52B (plungers) respectively connected to the three crank portions of the crankshaft. The motor 51 rotates upon receiving a command signal from the controller 60, and rotates the crankshaft 52A in the oil supply mechanism 52. Each discharge cylinder 52B corresponds to a plunger pump, and sucks the lubricating oil from the lubricating oil tank 53 and discharges the lubricating oil toward the leakage prevention part 100 as the crankshaft 52A rotates. At this time, the lubricating oil is supplied through the lubricating oil piping 18 in FIG. 2, and the lubricating oil flows into the oil inlet 18A formed in the fixed side seal member 10. The oil inlet 18A penetrates the fixed side seal member 10 and communicates with the sliding part with the rotating side seal member 9. As a result, a lubricating oil layer W (FIG. 3) is formed between the rotating side seal member 9 and the fixed side seal member 10. The three crank portions of the crankshaft 52A are arranged at 120 degree intervals along the rotational direction, and are set with equal phase differences from one another.

[0032] The oil amount adjusting mechanism 54 adjusts the stroke of the piston of the discharge cylinder 52B when the crankshaft 52A of the oil supply mechanism 52 makes one rotation, thereby adjusting the amount of lubricating oil 52C discharged from each discharge cylinder 52B. The oil amount adjusting mechanism 54 may be operated by an operator, or may adjust the stroke of the piston in response to a command signal received from the controller 60.

[0033] As shown in FIG. 3, in this embodiment, the lubricating oil is supplied between the stationary seal member 10 and the rotating seal member 9 from three oil inlets 18A formed in the stationary seal member 10. At this time, the lubricating oil is supplied to each oil inlet 18A in sequence due to the phase difference between the three crank parts of the crankshaft of the lubricating oil supply mechanism 50. FIG. 4 is a graph showing the transition of the oil film thickness of the seal part according to the rotation speed of the lubricating oil supply mechanism 50 of the closed type kneader 1 according to this embodiment. FIG. 5 is a graph in which a part (bold frame part) of the graph in FIG. 4 is enlarged. FIG. 4 shows the oil film thickness at each oil supply interval according to the rotation speed of the motor 51 under the condition that the total amount of oil supply is constant.

[0034] In Fig. 4, the graphs for the four conditions other than 60 rpm (3 cranks) show the transition of the oil film thickness according to the rotation speed of the motor 51 in a hypothetical case where one crank portion is arranged on the crankshaft 52A in Fig. 3. As shown in Fig. 4, it can be seen that the higher the rotation speed of the motor 51, i.e., the shorter the oil supply interval, the smaller the fluctuation in the oil film thickness and the larger the minimum oil film thickness.

[0035] On the other hand, 60 rpm (3 cranks) in Fig. 4 shows the transition of the oil film thickness when the motor 51 rotates at 60 rpm in the case where three crank sections are provided on the crankshaft 52A as shown in Fig. 3. As shown in Fig. 4 and Fig. 5, when the discharge cylinders 52B are provided on the crank sections that are 120 degrees out of phase with each other, it is confirmed that the minimum oil film thickness is the largest compared to the other four conditions.

[0036] FIG. 6 is a graph showing the average oil supply amount in the lubricant supply mechanism 50 of the kneader 1 according to this embodiment, which corresponds to the condition of 60 rpm (3 cranks) in FIG. 4 and FIG. 5. In FIG. 6, the oil supply amount from the discharge cylinders corresponding to the three crank parts is shown as q (+0°), q (+120°), and q (+240°), and the average oil supply amount is shown as sum q. As shown in FIG. 6, if the oil supply amount from each discharge cylinder is ideally expressed as a sine wave, the average oil supply amount is a superposition of three sine waves, and a state close to continuous supply can be formed despite the intermittent supply. As a result, as described above, the minimum oil film thickness can be maintained large. On the other hand, compared with the case where a constant amount of lubricant is continuously supplied, wasteful supply can be reduced and the oil film thickness can be stably maintained.

[0037] FIG. 7 is a graph showing the relationship between the total oil amount per hour and the oil film thickness for an internal mixer. The graph corresponds to the results of an experiment conducted to explain the effect of the mixer 1 according to this embodiment. The oil film thickness in FIG. 7 is the thickness immediately below the oil inlet 18A, for example. Table 1 shows the details of each data shown in FIG. 7. [Table 1]

[0038] FIG. 7 and Table 1 compare the oil film thickness when the rotation speed of the motor 51 is reduced without changing the amount of oil supplied per revolution (white circles) and when the rotation speed of the motor 51 is reduced without changing the amount of oil supplied per revolution (black circles), based on the oil film thickness when the rotation speed of the motor 51 is 60 rpm and the amount of lubricating oil supplied per revolution by the discharge cylinder 52B is 0.75 cc (inside the thick frame). As shown in FIG. 7, the oil film thickness changes more significantly in the data group in which the rotation speed of the motor 51 is changed than in the data group in which the amount of oil supplied per revolution is changed. These results confirm that the rotation speed of the motor 51 contributes more to the oil film thickness than the amount of oil supplied per revolution. That is, as with the graphs in FIG. 4 and FIG. 5, it can be seen that the oil film thickness is closely related to the oil supply interval.

[0039] In this embodiment, based on the above results, a lubricating oil supply mechanism 50 that supplies lubricating oil to the sliding portion between the rotating side seal member 9 and the fixed side seal member 10 periodically repeats the supply operation and the stopping operation of the lubricating oil so as to intermittently supply lubricating oil to the sliding portion.

[0040] According to this configuration, the total amount of lubricating oil supplied to the sliding parts can be reduced while the oil film thickness required for the lubricating function can be stably maintained. As a result, by reducing the amount of oil used, the impact on the environment caused by waste oil is reduced, and the running costs of the kneader 1 can be reduced. Furthermore, in this embodiment, the lubricating oil is intermittently supplied by the lubricating oil supply mechanism 50, so that the pulsating supply action can prevent momentary oil outflow from the sliding parts, thereby further improving the lubricating effect.

[0041] In this embodiment, the yoke 20 (pressing member) comes into contact with the fixed seal member 10 at a plurality of yoke pins 21 (pressing points) and presses the fixed seal member 10 toward the rotating seal member 9. The lubricant supply mechanism 50 has a plurality of oil inlets 18A for supplying lubricant to the sliding parts in the vicinity of each of the plurality of yoke pins 21. Here, as an example, the vicinity can be within a range of ±10 degrees in the rotational direction.

[0042] With this configuration, the sealing pressure between the fixed seal member 10 and the rotating seal member 9 is highest at the yoke pin 21 of the yoke 20, and the sealing pressure is low at the point farthest from the yoke pin 21 in the direction of rotation. If the oil inlet 18A were provided at a location where the sealing pressure was low, the oil pressure would open up a gap between the two seal members, increasing the amount of oil that leaks out, resulting in a waste of lubricating oil. On the other hand, with the above configuration, the oil film thickness in the vicinity of the yoke pin 21 of the yoke 20 is relatively large, and oil film breakdown can be effectively prevented, so that the sealing function of the leakage prevention part 100 can be maintained even if the amount of lubricating oil supplied is reduced.

[0043] In addition, in an intermittent oil supply mechanism such as that of this embodiment, the oil film thickness may be significantly reduced when oil supply is stopped, and wear is likely to occur when the oil film is small. Therefore, a hydrostatic oil supply mechanism, which does not fluctuate in the amount of oil supplied, appears to be more advantageous in terms of oil film formation than such an intermittent oil supply mechanism. However, it is known that such a hydrostatic mechanism, which always supplies a constant amount of oil, has a complex structure. Therefore, in this embodiment, while adopting an intermittent oil supply mechanism, attention is paid to how to shorten the oil supply interval, that is, to approach the hydrostatic oil supply mechanism, and as a result, an increase in the oil film thickness is realized.

[0044] Here, the inventor of the present invention conducted further experiments in addition to the above experiments and found that it is preferable to supply oil from one oil inlet 18A at least once per second, more preferable to supply oil at least 1.5 times per second, and most preferable to supply oil at least 2.0 times per second. With this configuration, it is possible to shorten the period during which lubricating oil is not supplied to the sliding portion between the two seals.

[0045] In addition, in order to suppress the consumption of lubricating oil, it is more preferable to set the amount of oil supplied per revolution to 0.3 cc or less.

[0046] 3, the lubricating oil supply mechanism 50 has a plurality of plunger pump structures with different oil supply timings (having phase differences), thereby shortening the oil supply interval between the rotating seal member 9 and the fixed seal member 10. In particular, as in this embodiment, by providing three or more oil supplies per rotation of the motor 51 and providing a phase difference between each of them, the oil supply interval can be further shortened.

[0047] Next, a modified embodiment of the present invention will be described. FIG. 8 is a schematic perspective view showing an oil supply structure to the leakage prevention unit 100 of the kneader 1 according to this modified embodiment. FIG. 9 is a plan view of the leakage prevention unit 100 of FIG. 8. FIG. 10 is a sectional perspective view including the section XI-XI of the leakage prevention unit 100 of FIG. 9. FIG. 11 is a sectional view of the leakage prevention unit 100 of FIG. 9 at the section XI-XI. FIG. 12 is a graph showing the distribution of the depth of the groove 10A of the fixed side seal member 10 shown in FIG. 10 and FIG. 11. The horizontal axis of the graph in FIG. 12 corresponds to the angle θ in FIG. 9. The "pressing" portion shown in FIG. 12 corresponds to the yoke pin 21 in FIG. 9 to FIG. 11.

[0048] Referring to Fig. 8, in this embodiment, two oil inlets 18A are provided in the fixed seal member 10. In this case, the lubricant supply mechanism 50 shown in Fig. 3 also has two discharge cylinders, and oil is alternately supplied due to the phase difference between them. As shown in Figs. 10 and 11, an annular groove 10A is provided in the surface of the fixed seal member 10 that faces the rotating seal member 9. As a result, the groove 10A has the effect of storing lubricant between the rotating seal member 9 and the fixed seal member 10 (oil pool effect).

[0049] Furthermore, the depth of the groove 10A of the fixed seal member 10 is set to vary along the rotational direction of the rotating seal member 9. In particular, in this modified embodiment, the oil inlet 18A is disposed upstream of the yoke pin 21 in the rotational direction, and the depth of the groove 10A is set to become shallower from the oil inlet 18A toward the yoke pin 21, as shown in Figures 11 and 12.

[0050] 11, when lubricating oil is supplied from oil inlet 18A while rotating side seal member 9 is rotating in the rotational direction, the lubricating oil that has flowed into groove 10A tries to move toward yoke pin 21 due to the rotational force of rotating side seal member 9. However, because groove 10A is inclined so that its depth is shallow as described above, the flow is suppressed (wedge effect).

[0051] According to this configuration, the oil pooling effect of the groove 10A and the wedge effect of the inclination provided in the groove 10A can make the pressure near the yoke pin 21 relatively high. Therefore, even if the amount of lubricating oil supplied is reduced, the oil film can be effectively prevented from breaking, and the sealing function of the leakage prevention part 100 can be stably maintained. In particular, the lubricating oil that flows into the groove 10A from the oil inlet 18A is prevented from moving downstream in the rotation direction near the yoke pin 21 and flows upstream in the rotation direction. Therefore, it is possible to impart a moving force along the rotation direction to the lubricating oil that has been poured, and the oil film thickness can be increased by turning back the lubricating oil. Furthermore, the lubricating oil can be stably supplied to the entire area of ​​the groove 10A in the rotation direction by the turned back lubricating oil. As a result, the rotating side seal member 9 is floated relatively to the fixed side seal member 10, and the rotation performance of the kneading rotor 2 can be stably maintained.

[0052] Furthermore, with the above-mentioned configuration, when viewed along the direction of rotation, the supply of lubricating oil to areas with large mechanical pressure is promoted, and the supply of lubricating oil to areas with small mechanical pressure is reduced. As a result, the unevenness of the amount of oil flowing out between the rotating seal member 9 and the fixed seal member 10 is reduced, and it becomes possible to maintain the sealing function with a small amount of oil.

[0053] The depth of the groove 10A is not limited to the above. For example, the depth of the groove 10A may be set according to the number, shape, flow path structure, etc. of the oil inlet 18A. By setting the depth of the groove 10A to vary along the rotation direction of the rotating side seal member 9, it becomes possible to partially change the pressure of the lubricating oil in the groove 10A, and the flow of the lubricating oil in the groove 10A can be adjusted by the pressure difference.

[0054] Although the kneader 1 according to each embodiment of the present invention has been described above, the present invention is not limited thereto, and further modified embodiments such as those exemplified below can be adopted.

[0055] 2 and 3, the lubricating oil supply mechanism 50 is described as being composed of the crankshaft 52A connected to the motor 51 and the three discharge cylinders 52B, but the present invention is not limited to this. An opening / closing valve may be provided in the oil supply passage communicating with the multiple oil inlets 18A of the fixed side seal member 10, and the supply and stop of the lubricating oil may be periodically repeated by opening and closing the opening / closing valve.

[0056] In each of the above-described embodiments, the fixing structure of the stationary seal member 10 by the yoke 20 is not limited to two-point support, but may have three or more support points.

[0057] In addition, the phases of the three crank parts shown in Fig. 3 are not limited to 120 degree intervals. The phases of two crank parts and the remaining crank part may be set to 180 degree intervals, so that lubricating oil is alternately supplied to two of the three oil inlets 18A and the remaining oil inlet 18A.

[0058] Furthermore, unlike the above-described embodiments, the pressing points may be pressed individually by actuators such as cylinders or springs, without using a mechanical pressing mechanism such as the yoke 20 or the like. [Explanation of symbols]

[0059] 1. Mixer (internal mixer) 2 Kneading rotor 2A Rotor shaft 2B Mixing wing section 3. Casing 3a Inlet 3b Outlet 4. Chamber 4a Mixing room 5. Ram 6. Drop Door 7 Rotor shaft 9 Rotating side seal member (rotating side seal) 10 Fixed side seal member (fixed side seal) 10A groove 16 Cooling piping 18 Lubricating oil piping 18A Oil filler port 20 Yoke (pressing member) 21 Yoke pin (pressure point) 22 yoke stud 23 Hydraulic cylinder 50 Lubricating oil supply mechanism 51 Motor 52 Oil supply mechanism 53 Lubricating Oil Tank 54 Oil amount adjustment mechanism 60 Controller 100 Leakage prevention part W Lubricating oil layer

Claims

1. A casing including a chamber for accommodating an object to be mixed therein; A kneading rotor including a rotor shaft portion extending outside the chamber and a kneading blade portion disposed inside the chamber, and kneading the material to be kneaded in the chamber by rotating; a leakage prevention unit that prevents the material to be kneaded in the chamber from leaking to the outside of the chamber; Equipped with The leakage prevention portion is a stationary seal attached to the casing so as to surround the rotor shaft; a rotating seal attached to the rotor shaft portion so as to face the stationary seal and rotatable while sliding relative to the stationary seal; a lubricating oil supply mechanism that supplies lubricating oil to a sliding portion between the fixed side seal and the rotating side seal, the lubricating oil supply mechanism periodically repeating a supply operation and a stop operation of the lubricating oil so as to intermittently supply the lubricating oil to the sliding portion.

2. a pressing member that contacts the stationary seal at a plurality of pressing points and presses the stationary seal toward the rotating seal; 2. The internal mixer according to claim 1, wherein the lubricating oil supply mechanism has a plurality of oil inlets for supplying lubricating oil to the sliding portion in the vicinity of each of the plurality of pressing points.

3. 3. The internal mixer according to claim 2, wherein a ring-shaped groove is provided on a surface of the stationary seal that faces the rotating seal, and the depth of the groove is set to vary along the rotation direction of the rotating seal.

4. The oil inlet is disposed upstream of the pressing point in the rotation direction, 4. The internal mixer according to claim 3, wherein the depth of the groove is set to become shallower from the oil inlet toward the pressing point.

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