Rotary nozzle

Abstract

To provide a rotary nozzle that is configured to enable a nozzle tube to be smoothly rotated continuously for a long time, while preventing a bearing from abrading an inner wall of a case.SOLUTION: A rotary nozzle comprises: a cylindrical case C1 composed of a case main body 30 and a bottom surface member 31 screw-joined to the case main body 30; bearings B1 and B2, embedded into the case, which comprise outer wheels 34 and inner rings 33 which can rotate relatively; and a nozzle tube 29 which is rotatably supported by the bearings B1 and B2 and protruded outward from the case C1 and is supplied with fluid. A pressing ring 40, which is arranged to oppose to an end face in an axial direction of the outer ring 34 and intervened between the outer wheel 34 and the bottom surface member 31, is provided in the case main body 30. When the bottom surface member 31 is fastened to the case main body 30 by screw-joining, the bearings B1 and B2 are fixed to the case main body 30, by fastening force in the axial direction acting on the outer wheel 34 through the pressing ring 40.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rotary nozzle that rotates due to the reaction force of a fluid jet. [Background technology]

[0002] Rotary nozzles that rotate while spraying high-pressure air are conventionally known. For example, the water removal device shown in FIG. 7 uses a rotary nozzle A shown in FIG. The water removal device of FIG. 7 has a net conveyor 2 provided on top of the device main body 1, and the object to be water-removed that has been washed with water is placed on this net conveyor 2 and transported.

[0003] Above the net conveyor 2, a unit cover 3 is provided which can cover or open the top surface of the net conveyor 2, and a first air injection unit 4 is attached inside this unit cover 3. This first air injection unit 4 is fitted with a plurality of rotary nozzles A which rotate while injecting high-pressure air guided from a high-pressure air source (not shown) to blow away water droplets adhering to the surface of the object to be dewatered on the net conveyor 2.

[0004] A second air injection unit 5 is provided below the transport path of the net conveyor 2. Although not shown, the second air injection unit 5 is also provided with a plurality of rotary nozzles A, similar to the first air injection unit 4. The rotary nozzles A inject high-pressure air while rotating from below the transported object to be dewatered, thereby blowing off water droplets from the surface of the object to be dewatered.

[0005] The specific configuration of the rotary nozzle A is as shown in Fig. 8, and includes a case 6, which has a bottom 6a on one side and an opening 6b on the opposite side. An inlet 7 for high-pressure air is provided in the bottom 6a, and a supply pipe 8 having a male thread 8a formed on its outer periphery is formed integrally with the inlet 7. This supply pipe 8 is attached to the air injection units 4, 5 of the water removal device or dust removal device described above.

[0006] A nozzle tube 9 is also incorporated into the case 6. This nozzle tube 9 is made up of a shaft portion 9a that is aligned with the central axis of the case 6 and supported within the case 6, a swirling portion 9b that is inclined with respect to the axis of the shaft portion 9a, and an injection port 9c. The swirling portion 9b is positioned and tilted at an angle relative to the shaft portion 9a so that the reaction force of the high-pressure air jetted from the nozzle 9c at the tip becomes a rotational force that rotates the shaft portion 9a.

[0007] The shaft portion 9a of the nozzle tube 9 is fitted into the case 6, and ball bearings 10 and 11 are inserted between the shaft portion 9a and the case 6 so as to be aligned in the axial direction of the shaft portion 9a. These ball bearings 10 and 11 have exactly the same configuration, and therefore will be described below using the same reference numerals. Ball bearings 10 and 11 incorporate a plurality of balls 12d held by a cage 12c between an inner ring 12a and an outer ring 12b. These ball bearings 10 and 11 allow smooth rotation of nozzle tube 9 even with a small rotational force such as the reactive force of high-pressure air injection, as balls 12d roll and inner ring 12a and outer ring 12b rotate relative to each other.

[0008] The shaft portion 9a of the nozzle tube 9 is inserted into the inner ring 12a, and a pair of retaining rings 13, 14 are fixed to the shaft portion 9a at a predetermined interval in the axial direction of the shaft portion 9a, and the inner ring 12a of the ball bearings 10, 11 is held between these retaining rings 13, 14. This integrates the shaft portion 9a and the inner ring 12a. Meanwhile, a retaining ring 15 is fixed to the inner wall of the case 6 on the opening 6b side, and a set screw 16 is screwed into the bottom 6a, with the outer ring 12b of the ball bearings 10, 11 fixed between the set screw 16 and the retaining ring 15. A spacer 17 is interposed between the retaining ring 15 on the shaft portion 9a and the outer ring 12b. This allows the outer ring 12b and the case 6 to be integrated.

[0009] A pair of retaining rings 18, 19 are provided on the shaft portion 9a on the side of the swivel portion 9b when viewed from the opening 6b of the case 6, and a cover 20 is interposed between these retaining rings 18, 19, with a wave washer 21 interposed between one of the retaining rings 18 and the cover 20. The elastic force of this wave washer 21 presses the cover 20 against the retaining ring 19 fixed to the shaft portion 9a, and the cover 20 is fixed to the nozzle tube 9.

[0010] The cover 20 as described above comprises a plate-shaped covering portion 20a and a bottom portion 20b continuous with the covering portion 20a. The covering portion 20a has a shaft hole 20c in the center whose inner diameter matches the outer periphery of the shaft portion 9a, and by inserting the shaft portion 9a into the shaft hole 20c, the covering portion 20a faces the opening 6b of the case 6 and covers the opening 6b.

[0011] In addition, the entire circumference of the bottom 20b of the cover 20 reaches at least the opening level of the opening 6b, and the cover 20 covers and closes the opening 6b of the case 6. This prevents water droplets, dust, and the like from entering the case 6 through the opening 6b. As mentioned above, the inner diameter of the axial hole 20c of the cover 20 is the same as the outer diameter of the axial portion 9a, so even if water droplets form on the surface of the covering portion 20a of the cover 20, they are less likely to enter the inside of the cover 20 through the axial hole 20c.

[0012] In addition, a small hole 22 is formed in the shaft portion 9a of the nozzle tube 9 between the retaining ring 15 fixed to the case 6 and the cover 20, so that the pressure of the high-pressure air introduced into the nozzle tube 9 is introduced into the cover 20 from the small hole 22. The pressure introduced into the cover 20 from these small holes 22 corresponds to the injection pressure of the high-pressure air and is higher than the pressure outside the cover 20. Therefore, while high-pressure air is being supplied to the nozzle tube 9, the pressure inside the cover 20 is maintained higher than the external pressure, and the high-pressure air escapes from inside the cover 20 to the outside, making it difficult for water droplets and the like to enter the interior through the gap between the bottom portion 20b of the cover 20 and the outer peripheral surface of the case 6.

[0013] With the above configuration, when high-pressure air is supplied to the first and second air injection units 4 and 5, the high-pressure air is guided from the supply pipe 8 to the nozzle tube 9 and is forcefully injected from the injection port 9c. At this time, the shaft portion 9a rotates due to the reactive force of the high-pressure air jet, and the swiveling portion 9b rotates around the axis of the shaft portion 9a, and the jet direction of the high-pressure air also rotates. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-042451 [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-176140 Summary of the Invention [Problem to be solved by the invention]

[0015] In the conventional rotary nozzle A described above, the ball bearings 10, 11 are pressed against the case 6 by two small set screws 16. However, it is difficult to equalize the tightening force of the pair of set screws 16, 16, which can result in differences in the pressing force on the outer ring 12b. Furthermore, the set screws 16 can become loose due to vibrations that occur during operation of the water removal device. As described above, if there is a difference in the pressing force of the pair of set screws 16, 16, the axes of the ball bearings 10, 11 may tilt with respect to the central axis of the case 6 or may rattle.

[0016] When the axes of ball bearings 10, 11 are tilted, outer ring 12b is not properly fixed to case 6, so when nozzle tube 9 is rotated in this state, outer ring 12b rotates along with inner ring 12a, rubbing against the inner wall of case 6 and generating wear powder. Also, if set screw 16 becomes loose, the entire ball bearings 10, 11 may rotate together with nozzle tube 9, causing outer ring 12b to rub against the inner wall of case 6 and generating wear powder. If the generated wear particles get into the ball bearings 10 and 11, they will adhere to the balls 12d and cause rotational resistance, hindering smooth rotation of the nozzle tube 9.

[0017] The nozzle tube 9 rotates using the reaction force of the high-pressure air jet as a rotational force, but this rotational force is very small. For example, even if you insert your finger to stop the rotation of the rotating part 9b while it is rotating, you will feel almost no pain and the rotation of the rotating part 9b will be stopped. Because the rotational force of the nozzle tube 9 is so small, if the above-mentioned wear powder gets into the ball bearings 10 and 11 and the rotational resistance increases even slightly, the nozzle tube 9 will stop rotating.

[0018] An object of the present invention is to provide a rotary nozzle that can prevent wear on the inner wall of the case and maintain smooth rotation for a long period of time. [Means for solving the problem]

[0019] A first invention is a rotary nozzle comprising: a cylindrical case; a supply pipe connected to the case and supplying a fluid to be supplied to the case; a bearing incorporated in the case and including outer and inner rings that are rotatable relative to one another; and a nozzle tube that is rotatably supported by the bearing and protrudes outward from the case and to which fluid is supplied from within the case, wherein the nozzle outlet of the nozzle tube rotates due to the reaction force of the fluid sprayed from the nozzle tube; the case comprises a case body from which the nozzle tube or the supply pipe protrudes, and a bottom member that is screwed to the case body to close the bottom surface on the side opposite to the side from which the nozzle tube or the supply pipe protrudes; a retaining ring is provided within the case body, positioned opposite to the axial end face of the outer ring, and interposed between the outer ring and the bottom member; when the bottom member is screwed to the case body, the outer ring is fixed to the case body by the axial tightening force acting on the outer ring via the retaining ring.

[0020] In a second invention, the nozzle tube comprises a linear shaft portion disposed within the case body and a swiveling portion protruding from the case body while maintaining an inclination angle relative to the shaft portion; an opening provided in the case body through which the shaft portion protrudes so as to be rotatable relative to the case body; and a cover member having a shape corresponding to the opening; the cover member comprises a tubular portion into which the shaft portion is inserted within the case body, which passes through the inner ring and is rotatably supported by the inner ring; and a plate-shaped cover portion extending continuously from one end of the tubular portion in the outer radial direction of the tubular portion and covering the opening from the outside of the case body; and the shaft portion, when inserted into the tubular portion, is rotatable integrally with the tubular portion by the inner ring.

[0021] In a third aspect of the present invention, the nozzle tube and the cover member are integrally molded.

[0022] In a fourth aspect of the present invention, the case is configured by joining a male thread provided on the outer periphery of the case body with a female thread provided on the inner periphery of the bottom member.

[0023] In a fifth aspect of the present invention, the inner diameter of the retainer ring is the same as the inner diameter of the outer ring of the bearing.

[0024] In a sixth aspect of the present invention, the nozzle tube is fixed to the case body, and the bottom member has an opening through which the supply pipe protrudes so as to be rotatable relative to the case body. The supply pipe is fixed to the inner ring within the case, and the case is rotatable integrally with the nozzle tube. [Effects of the Invention]

[0025] According to the first aspect of the present invention, the retaining ring can press the entire circumference of the outer ring of the bearing, allowing the pressing force to be applied evenly. Because the pressing force is applied evenly to the bearing, the bearing does not tilt or rattle. Therefore, no wear debris is generated from the inner wall of the case, and the smooth rotation of the rotary nozzle is not hindered by the intrusion of wear debris. In addition, the case is formed by a case body and a bottom member, and the bearing can be inserted from the bottom member side. Therefore, the diameter of the opening through which the nozzle tube or supply pipe is inserted can be minimized, which also prevents moisture, dust, and other foreign matter from entering the case through the opening.

[0026] According to the second aspect of the present invention, the opening through which the nozzle tube protrudes is covered by the cover member that rotates integrally with the nozzle tube, thereby preventing water droplets and the like from entering the case. Therefore, it is possible to prevent foreign matter from entering from the outside from interfering with the smooth rotation of the nozzle tube. Furthermore, because the cylindrical portion of the cover member into which the nozzle tube is inserted is inserted into the inner ring, even if water droplets do enter the case along the outer periphery of the nozzle tube, they pass through the cylindrical portion inside the inner ring and do not enter the bearing, thereby reliably preventing rotational resistance caused by water droplets.

[0027] According to the third aspect of the present invention, the nozzle tube and the cover member are integrated, eliminating any gap between them, so that water droplets adhering to the nozzle tube do not flow along the outer periphery of the nozzle tube into the case, thereby more reliably preventing rotational resistance caused by water droplets. Furthermore, the number of parts is reduced and the process of attaching the cover member can be omitted, improving the workability of assembling the rotary nozzle.

[0028] According to the fourth aspect of the present invention, since the bottom member is located outside the case body, when the supply pipe is fixed to the bottom member, a tool for attaching and detaching the supply pipe can be fitted around the outer periphery of the bottom member. There is no need to provide a separate part for fitting the tool, and the axial length of the rotary nozzle does not increase.

[0029] According to the fifth aspect of the present invention, the force of the retainer ring is likely to act evenly over the entire outer ring of the bearing, and the bearing can be more reliably fixed to the case.

[0030] According to the sixth aspect of the present invention, the nozzle tube and case rotate together with the outer ring, which has a relatively large diameter, making the rotation axis less likely to tilt than when the inner ring rotates. This means that the case can be supported more stably and wear on the case due to bearing rattle can be prevented. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a cross-sectional view of a rotary nozzle according to a first embodiment. [Figure 2] FIG. 2 is a front view of the cover member of the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view of a rotary nozzle according to the second embodiment. [Figure 4] FIG. 4 is a front view of a nozzle tube with a cover according to the second embodiment. [Figure 5] FIG. 5 is a cross-sectional view of a rotary nozzle according to the third embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a rotary nozzle according to the fourth embodiment. [Figure 7] FIG. 7 is a perspective view of the water removal device. [Figure 8] FIG. 8 is a cross-sectional view of a conventional rotary nozzle used in a water removal device. DETAILED DESCRIPTION OF THE INVENTION

[0032] [First embodiment] A first embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a cross-sectional view of a rotary nozzle N1 of the first embodiment, and Figure 2 is a front view of a cover member. As shown in FIG. 1, the rotary nozzle N1 of the first embodiment has a nozzle tube 29 rotatably supported by a pair of ball bearings B1 and B2 that are incorporated into a case C1. Like the conventional nozzle tube 9 shown in Figure 8, the nozzle tube 29 consists of a linear shaft portion 29a supported by ball bearings B1 and B2 inside the case C1, a swiveling portion 29b that maintains an inclination angle relative to the shaft portion 29a, and an injection port 29c.

[0033] The case C1 of the first embodiment is made up of a case body 30 and a bottom member 31. The case body 30 is cylindrical and has an opening 30a at one axial end face through which the swirling portion 29b of the nozzle tube 29 protrudes, and an open portion 30b at the other end (opposite side). A male thread 30c is formed on the outer surface on the open portion 30b side.

[0034] The bottom member 31 has a flat bottom portion 31a and a sidewall portion 31b along its outer periphery. A through-hole 31c is formed in the center of the bottom portion 31a to guide high-pressure air into the case C1. The bottom member 31 also has a supply pipe 32 that protrudes from the bottom portion 31a to the side opposite the sidewall portion 31b. The inner circumferential surface of the supply pipe 32 is formed to be continuous with the through-hole 31c. The supply pipe 32 supplies high-pressure air into the case C1 through the through-hole 31c. A male thread 32a is formed on the outer periphery of the supply pipe 32. Furthermore, an internal thread 31d that meshes with the external thread 30c of the case body 30 is formed on the inner peripheral surface of the side wall portion 31b of the bottom member 31. By joining the internal thread 31d with the external thread 30c, the case C1 is formed, in which the case body 30 and the bottom member 31 are integrated. Meanwhile, the external peripheral surface of the side wall portion 31b of the bottom member 31 has a polygonal planar shape such as a regular hexagon. In the drawing, reference numeral 30d denotes a notch formed on the outer circumferential surface of the case body 30, into which a tool such as a wrench is inserted when joining the case body 30 to the bottom member 31.

[0035] The pair of ball bearings B1, B2 assembled into the case C1 have the same configuration, and therefore their respective components will be described using the same reference numerals. The ball bearings B1, B2 are configured with a plurality of balls 35 interposed between an inner ring 33 and an outer ring 34, and these balls 35 are held in a cage 36. In the following description, the upper ball bearing B1 in the drawing will be referred to as the first ball bearing B1, and the lower ball bearing B2 in the drawing will be referred to as the second ball bearing B2.

[0036] The rotary nozzle N1 also includes a cover member 37 (see FIG. 2) that is attached to the nozzle tube 29. 1 and 2 includes a cylindrical portion 37a and a cover portion 37b. The inner diameter of the cylindrical portion 37a matches the outer diameter of the shaft portion 29a of the nozzle tube 29, and the outer diameter of the cylindrical portion 37a matches the inner diameter of the inner ring 33 of the ball bearings B1 and B2. The cover portion 37b is formed at one end of the cylindrical portion 37a and has a disk shape that expands in the radially outward direction. A skirt portion 37c is formed on the outer peripheral edge of the cover portion 37b, extending downward in the drawing, i.e., toward the bottom member 31 of the case C1. The cylindrical portion 37a has a stepped portion 37d formed by increasing the outer diameter within a bottom portion 37c on the cover portion 37b side. When the cylindrical portion 37a is inserted into the inner ring 33, the stepped portion 37d abuts against the end face of the inner ring 33, thereby serving as an axial stopper for the inner ring 33.

[0037] Ball bearings B1, B2, etc. are incorporated into the case C1 as described above, and the assembly structure is as follows. The shaft portion 29a is inserted into the cylindrical portion 37a of the cover member 37 from above in the drawing, and the shaft portion 29a of the nozzle tube 29 with the cover member 37 attached is inserted into the case main body 30 through the opening 30a. A pair of ball bearings B1 and B2 are inserted into the cylindrical portion 37a from below in the drawing and attached. Thereafter, a pair of retaining rings 38 and 39 are fitted to the shaft portion 29a near both ends thereof, and the cover member 37 and the inner rings 33 of the ball bearings B1 and B2 are held between these retaining rings 38 and 39.

[0038] A retaining ring 40 is interposed between the outer ring 34 of the second ball bearing B2 and the inner bottom surface 31e of the bottom member 31. The retaining ring 40 is tubular, and its outer diameter is set slightly smaller than the inner diameter of the side wall of the case body 30 to allow axial movement. This makes it easy to insert the retaining ring 40 into the case body 30. Furthermore, the axial length of the retaining ring 40 is set slightly larger than the distance from the end of the open portion 30b to the lower end face of the outer ring 34 of the second ball bearing B2 in the drawing when the pair of ball bearings B1 and B2 are pressed against the inner bottom surface 30e of the case body 30. In other words, the end face of the retaining ring 40 inserted into the case body 30 protrudes slightly from the end of the open portion 30b of the case body 30 (the end face of the peripheral wall of the case body 30) to the outside of the case body 30 (toward the bottom member 31). The inner diameter of the retainer ring 40 is made to match the inner diameter of the outer ring 34 .

[0039] The above-mentioned retaining ring 40 is inserted into the case body 30 from the downward direction in the drawing, and placed in the case body 30 together with the ball bearings B1 and B2. Then, the case body 30 and the bottom member 31 are screwed together using the male thread 30c of the case body 30 and the female thread 31d of the bottom member 31 to form the rotary nozzle N1. 7 by tightening the male thread 32a of the supply pipe 32 to the air injection units 4 and 5. At this time, a wrench or the like is applied to the outer peripheral surface of the peripheral wall of the bottom member 31, which is formed in a regular hexagon or the like, to attach or detach the supply pipe 32 to or from the water removal apparatus, or to screw the bottom member 31 to the case main body 30.

[0040] Note that reference numeral 41 in Figure 1 denotes an oil supply hole that penetrates the bottom member 31 to supply oil to the ball bearings B1 and B2. With this oil supply hole 41, it is possible to supply oil to the ball bearings B1 and B2 without disassembling the case C1. However, with the rotary nozzle N1 of this embodiment, the oil supply hole 41 is not necessary because the ball bearings B1 and B2 can be easily oiled by removing the bottom member 31. Also, the oil supply hole 41 may be provided with a cap made of rubber or the like (not shown).

[0041] [Actions and effects] In the rotating nozzle N1 of the first embodiment, when the bottom member 31 is screwed to the case body 30, the pressing force of the retaining ring 40 acting on the outer ring 34 of the second ball bearing B2 presses the first ball bearing B1 against the inner bottom surface 30e of the case body 30. The axial length of the retaining ring 40 is set so that it protrudes slightly outward from the open portion 30b of the case body 30, so that the inner bottom surface 31e of the screw-connected bottom member 31 reliably presses against one end face of the retaining ring 40 on the bottom member 31 side. At this time, the entire other end face of the retaining ring 40 contacts the entire end face of the outer ring 34 of the second ball bearing B2. Therefore, the pressing force of the retaining ring 40 can be applied evenly around the entire circumference of the outer ring 34 of the second ball bearing B2. As a result, the ball bearings B1, B2 do not tilt or rattle.

[0042] Furthermore, if the inner diameter of the retaining ring 40 matches the inner diameter of the outer ring 34 of the second ball bearing B2, a pressing force can be applied across the entire diametric width of the outer ring 34 of the second ball bearing B2, allowing for more secure fixation. Therefore, the generation of wear powder on the inner wall of the case body 30 is suppressed, and the movement of the ball bearings B1, B2 is not hindered by the intrusion of wear powder.

[0043] Furthermore, the cover member 37 can prevent water droplets adhering to the swivel portion 29b from entering the inside of the case main body 30. Specifically, because the opening 30a is covered by the cover portion 37b and the skirt portion 37c, water droplets can be prevented from entering through the opening 30a. Furthermore, because the outer diameter of the shaft portion 29a of the nozzle tube 29 matches the inner diameter of the tubular portion 37a of the cover member 37, water droplets rarely enter the case C1 along the outer periphery of the shaft portion 29a. Even if water droplets along the outer periphery of the shaft portion 29a do enter the case C1, the water droplets flow along the inner wall of the tubular portion 37a of the cover member 37 and do not flow directly into the cage 36 of the ball bearings B1 and B2. Therefore, water droplets do not enter and cause rotational resistance in the ball bearings B1 and B2.

[0044] If water droplets adhere to the ball 35 of the cage 36, the minerals, dust, and other foreign matter contained in the water droplets may cause rotational resistance of the ball 35. If the rotational resistance increases even slightly due to the intrusion of foreign matter, the nozzle tube 29 will not be able to rotate smoothly, but the rotary nozzle N1 equipped with the cover member 37 of the first embodiment can prevent the occurrence of rotational resistance due to the intrusion of such water droplets.

[0045] Furthermore, because the cylindrical portion 37a of the cover member 37 acts as a spacer between the shaft portion 29a of the nozzle tube 29 and the ball bearings B1, B2, it is possible to increase the diameter of the inner ring 33 and employ larger ball bearings B1, B2 compared to when ball bearings are attached directly to the shaft portion 29a of the nozzle tube 29. This allows the nozzle tube 29 to rotate more stably and extends the life of the ball bearings attached to the rotary nozzle N1.

[0046] In order to confirm the durability of the rotary nozzle N1 of this embodiment, the rotary nozzle N1 was attached to the water removal device shown in Fig. 7, and an operation test of the water removal device was carried out. Specifically, seven rotary nozzles N1 were attached to the water removal device, and the operation in the water removal process after the product was washed with water was continued without maintenance. On the other hand, for the conventional rotary nozzle A, compressed air was supplied to multiple rotary nozzles A and they were rotated in a place where there was no water scattering, not during the water removal process. In both cases, operation was repeated daily for 4 to 12 hours / day.

[0047] As a result, all of the rotary nozzles N1 maintained the desired smooth rotation state after a total operating time of approximately 1070 hours had elapsed, and the operating test has continued since then. In contrast, the conventional rotary nozzle A began to stop and rotate intermittently after the total operating time exceeded approximately 950 hours. When rotary nozzle A was inspected, it was found that the set screws 16, 16 had come loose and the inner wall of the case 6 was worn away. From these findings, it was confirmed that the rotary nozzle N1 of the first embodiment can prevent wear on the inner wall of the case and maintain smooth rotation for a long period of time. Furthermore, the rotary nozzle N1 did not experience any problems due to water droplets entering the nozzle.

[0048] [Second embodiment] 3 and 4 shows a rotary nozzle N2 in which a nozzle tube 42 with a cover is assembled into a case C2. Fig. 3 is a cross-sectional view of the rotary nozzle N2, and Fig. 4 is a front view of the nozzle tube 42. The second embodiment has almost the same structure as the rotary nozzle N1 of the first embodiment, except for the nozzle tube 42. Therefore, in Figure 3, the same components as those in the first embodiment are given the same reference numerals as in Figure 1, and detailed description of each component will be omitted.

[0049] 3, a nozzle tube 42 of the second embodiment is a member obtained by integrating the nozzle tube 29 of the first embodiment with a cover member 37. The nozzle tube 42 includes a linear shaft portion 42a, a swiveling portion 42b that maintains an inclination angle with the axis of the shaft portion 42a, and an injection port 42c. A covering portion 37b and a skirt portion 37c similar to those of the cover member 37 are integrally formed with the shaft portion 42a. Furthermore, the outer diameter of the portion of the shaft portion 42a that is supported by the ball bearings B1 and B2 is made to match the inner diameter of the inner rings 33 of the ball bearings B1 and B2.

[0050] As shown in FIG. 3, in the second embodiment, the retaining ring 38 used to fix the cover member 37 shown in FIG. 1 is omitted, but the other configurations are the same as those of the rotary nozzle N1 of the first embodiment shown in FIG. 1. In the second embodiment, the rotary nozzle N2 also has a pressure ring 40 interposed between the inner bottom surface 31e of the bottom member 31 of the case C2 and the ball bearing B2, and this pressure ring 40 applies a pressure force to the outer rings 34 of the ball bearings B1 and B2.

[0051] [Actions and effects] In the second embodiment, the retaining ring 40 also applies a uniform pressing force to the entire circumference of the outer ring 34 of the second ball bearing B2. This prevents tilting or rattle of the ball bearings B1 and B2, and prevents wear on the inner wall of the case body 30. This allows smooth rotation to be maintained for a long period of time. Other effects similar to those of the first embodiment can be obtained.

[0052] In the second embodiment, the cover is integrated with the nozzle tube 42, eliminating the need for the retaining ring 38 used in the first embodiment to secure the cover member 37. This reduces the number of parts and simplifies the assembly process, improving workability. Furthermore, since there is no gap between the shaft portion 42a of the nozzle tube 42 and the cover portion 37b, there is no risk of water droplets running along the outer periphery of the shaft portion 42a or the swivel portion 42b entering the case C2.

[0053] [Third embodiment] FIG. 5 is a cross-sectional view of a rotary nozzle N3 according to the third embodiment. The rotary nozzle N3 of the third embodiment has a nozzle tube 29 rotatably supported on a case C3 by a pair of ball bearings B1 and B2. Other than the configuration of the case C3, the third embodiment is the same as the first embodiment. In Fig. 5, the same reference numerals as in Fig. 1 indicate the same components as in the first embodiment.

[0054] The case C3 of the third embodiment is made up of a case body 43 and a bottom member 44. The case body 43 has an opening 43a through which the nozzle tube 29 protrudes, an open portion 43b through which ball bearings B1 and B2 are inserted toward the inner bottom surface 43e, a female thread 43c formed on the inner periphery, and a notch 43d for a tool formed on the outer periphery. The bottom member 44 has a disk-shaped bottom portion 44a, with a through hole 44b formed in the center for guiding high-pressure air to the nozzle tube 29. The bottom portion 44a also has a supply pipe 32 formed therein that is continuous with the through hole 44b and protrudes outward from the bottom surface. The supply pipe 32 supplies high-pressure air into the case C3 through the through hole 44b. A male thread 32a is formed on the outer periphery of the supply pipe 32.

[0055] Furthermore, a male thread 44c that meshes with the female thread 43c of the case body 43 is formed on the outer surface of the bottom portion 44a of the bottom member 44. The case C3 is configured by threadably coupling the case body 43 and the bottom member 44 with this male thread 44c and the female thread 43c, which is different from the other embodiments. In this third embodiment, the retaining ring 40 is also interposed between the inner bottom surface 44d of the bottom member 44 and the outer ring 34 of the second ball bearing B2 to exert a pressing force toward the inner bottom surface 43e of the case main body 43.

[0056] [Actions and effects] In this third embodiment, too, by screwing together the case body 43 and the bottom member 44, the retaining ring 40 interposed between the inner bottom surface 44d of the bottom member 44 and the outer ring 34 of the second ball bearing B2 can apply an even pressing force to the entire circumference of the outer ring 34 of the ball bearings B1 and B2. Also, the cover member 37 closes the opening 43a to prevent water droplets and the like from entering the case body 43, which is the same as in the first embodiment. The third embodiment is opposite to the first embodiment in the relationship between the male and female threads of the case body and the bottom member. In this way, the male thread may be provided on either the case body or the bottom member that are screwed together.

[0057] However, when the external threads 44c are formed on the outer surface of the bottom member 44 as in the third embodiment, the case body 43 cannot be turned when tightening or loosening the external threads 32a of the supply pipe 32 to the air injection units 4, 5. This is because turning the case body 43 may tighten or loosen the case body 43 rather than the external threads 32a of the supply pipe 32. This can be solved by providing a holder on the bottom member 44 for holding tools or fingers so that force is not applied to the case body 43, but this increases the overall axial length by the length of the holder.

[0058] [Fourth embodiment] FIG. 6 is a cross-sectional view of a rotary nozzle N4 according to the fourth embodiment. The rotary nozzle N4 of the fourth embodiment is configured so that the case C4 rotates together with the nozzle tube 45. Similar to case C1 shown in Fig. 1, case C4 is configured by screwing together case main body 30 and bottom member 31. Case C4 in the fourth embodiment is upside down compared to case C1 of the first embodiment shown in Fig. 1, but the ball bearings B1 and B2 and retaining ring 40 incorporated in case C4 are the same as those in the first embodiment, and the same reference numerals as in Fig. 1 are used for the same components as in the first embodiment.

[0059] The following description will focus on the differences from the first embodiment. The shaft 45a of the nozzle tube 45, which is continuous with the central through-hole 31c, is integrally formed on the bottom surface portion 31a of the bottom surface member 31. This nozzle tube 45 also has a swirl portion 45b that maintains an inclination angle with respect to the linear shaft portion 45a, and an injection port 45c. In this fourth embodiment, since the nozzle tube 45 and the bottom surface member 31 are integrally configured, water droplets along the outer periphery of the nozzle tube 45 or water droplets scattered by the ejected air do not enter the case C4 from the swirl portion 45b side. For this reason, the cover member 37 of the first embodiment is omitted.

[0060] Ball bearings B1 and B2 are incorporated in the case body 30, and a supply pipe 46 for supplying high-pressure air to the nozzle tube 45 is inserted into the inner ring 33 of the ball bearings B1 and B2. In the fourth embodiment, the portion of the supply pipe 46 that is supported by the inner ring 33 is a large-diameter portion 46b that matches the inner diameter of the inner ring 33. A pair of retaining rings 47, 48 are attached to the supply pipe 46 at positions sandwiching the inner rings 33, 33 of the ball bearings B1, B2, and the supply pipe 46 and the inner ring 33 are integrated together. A male thread 46a is formed on the outer peripheral surface of the end side of the supply pipe 46 that protrudes from the case body 30 through the opening 30a of the case body 30, and this male thread 46a is used to attach the supply pipe 46 to the air injection units 4, 5 of the water removal device.

[0061] [Actions and effects] In the rotary nozzle N4 of the fourth embodiment, the nozzle tube 45 is integrated with the bottom member 31, and the supply pipe 46 is supported by the inner ring 33 so as to be rotatable relative to the case body 30. Therefore, the nozzle tube 45 and case C4 rotate together due to the injection force of high-pressure air. Since the case C4, which has a larger diameter than the shaft 45a of the nozzle tube 45, serves as the rotating body, there is less wobble of the rotation shaft compared to other embodiments in which the shaft of the nozzle tube rotates, and stable rotation is maintained. This allows for even less wobble in the ball bearings B1 and B2.

[0062] In addition, with respect to the rotary nozzle N4, a pressing force can be applied evenly to the entire circumference of the outer ring 34 of the second ball bearing B2 by means of a pressing ring 40 interposed between the inner bottom surface 31e of the bottom member 31 and the outer ring 34 of the second ball bearing B2. Therefore, the ball bearings B1 and B2 can be securely fixed to the case C4, and the inner wall of the case C4 will not be worn down by tilted or loose ball bearings B1 and B2. Therefore, the rotary nozzle N4 can maintain smooth rotation for a long period of time, and the frequency of maintenance can be reduced, similar to the other embodiments.

[0063] In the first to fourth embodiments, a pair of ball bearings B1 and B2 is used as the bearing. If the number of ball bearings is large, the axial length of the portion supported by the bearings becomes long, making it difficult for the rotation axis to wobble, but the number of ball bearings is not limited to two and can be any number.

[0064] Furthermore, the larger the diameter of the ball bearings B1 and B2, the more stable the rotation. Therefore, in the above embodiment, the cylindrical portion 37a of the cover member 37 is attached to the shaft portion 29a of the nozzle tube 29, and the shaft portion 42a and the large-diameter portion 46b of the supply pipe 46 are formed to fit the large-diameter inner ring 33, but this configuration is not essential. Furthermore, if the axial length or diameter of the bearing increases, the case will also become larger, so the size of the bearing should be selected appropriately taking into consideration the location of use, etc.

[0065] Furthermore, although the first to fourth embodiments use a nozzle tube with only one jet orifice, a single rotary nozzle may be provided with multiple jet orifices. For example, a nozzle tube may be used in which a single shaft portion branches into multiple swirl portions, each of which has a jet orifice, or an air reservoir may have multiple jet orifices. In these cases, the multiple jet orifices must maintain a jet direction and positional relationship such that the reaction force of the jetted fluid as a whole becomes a swirling force.

[0066] Furthermore, the high-pressure air sprayed from the rotary nozzles N1 to N4 can blow away not only water droplets but also dust adhering to the surface of objects being transported by the net conveyor 2. In other words, the rotary nozzles N1 to N4 can be used not only as a water removal device but also as a dust removal device. [Industrial Applicability]

[0067] The rotary nozzle of the present invention is ideal for use in water removal devices and dust removal devices. [Explanation of symbols]

[0068] N1, N2, N3, N4 rotating nozzle C1, C2, C3, C4 Case 30,43 Case body 30a,43a opening 31,44 Bottom member 30c, 44c male thread 31d, 43c female thread 32,46 Supply pipe 29, 42, 45 Nozzle tube 29a,42a,45a Shaft part 29b, 42b, 45b Swivel section 29c,42c,45c injection port B1, B2 (Bearing) Ball bearing 33 Inner Circle 34 outer ring 37 Cover member 37a Cylinder part 37b Cover 40 retaining ring

Claims

1. A cylindrical case and a supply pipe connected to the case and supplying the fluid to the case; a bearing incorporated in the case and including an outer ring and an inner ring that are rotatable relative to each other; a nozzle tube rotatably supported by the bearing, protruding outward from the case, and receiving fluid from inside the case; A rotary nozzle in which the nozzle tube's nozzle outlet rotates due to the reaction force of the fluid injected from the nozzle tube, the case includes a case body from which the nozzle tube or the supply pipe projects, and a bottom member that is screw-connected to the case body and closes the bottom surface on the side opposite to the side from which the nozzle tube or the supply pipe projects, a retaining ring disposed within the case body and disposed opposite an axial end face of the outer ring and interposed between the outer ring and the bottom member; When the bottom member is fastened to the case body by a screw connection, the outer ring is fixed to the case body by the axial fastening force acting on the outer ring via the retaining ring.

2. the nozzle tube comprises a linear shaft portion disposed within the case body and a swivel portion protruding from the case body and maintaining an inclination angle with respect to the shaft portion; an opening provided in the case body through which the shaft portion protrudes so as to be relatively rotatable; a cover member having a shape corresponding to the opening, The cover member is the shaft portion is inserted into the case body, the shaft portion passes through the inner ring, and the shaft portion is rotatably supported by the inner ring; and a plate-like cover portion is continuous with one end of the cylindrical portion, extends radially outward from the cylindrical portion, and covers the opening from the outside of the case body, The shaft portion is inserted into the cylindrical portion and is rotatable integrally with the cylindrical portion by the inner ring. The rotary nozzle of claim 1 .

3. 3. The rotary nozzle according to claim 2, wherein the nozzle tube and the cover member are integrally molded.

4. The above case is The case body is provided with a male screw on the outer periphery thereof and a female screw on the inner periphery thereof. The rotary nozzle of claim 1 .

5. The inner diameter of the retaining ring matches the inner diameter of the outer ring of the bearing. The rotary nozzle of claim 1 .

6. The nozzle tube is fixed to the bottom member, the case body has an opening through which the supply pipe protrudes so as to be relatively rotatable; the supply pipe is fixed to the inner ring within the case, 2. The rotary nozzle according to claim 1, wherein the case is rotatable integrally with the nozzle tube.

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