JP3653017B2 - Shaft seal device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shaft seal device for a low-speed rotating device using a shaft seal member. More specifically, the present invention relates to a shaft seal device that is excellent in a shaft shake tracking function, particularly in a radial displacement tracking capability, and that maintains a good sealing property.
[0002]
[Prior art]
The low-speed rotating device is a device mainly used for stirring, drying, kneading, and conveying fluids such as liquids and powders, and has a blade, a conveyor, and the like attached to a rotating shaft. Since it is necessary to prevent fluid leakage from the rotating shaft of the rotating device, shaft seal members such as gland packing and labyrinth seal are used, for example. In addition, it is known that the rotating shaft receives a load from a fluid to be used, for example, a highly viscous fluid such as resin, and the rotating shaft is decentered, causing shaft runout. As a result, the pressing force in the circumferential direction becomes non-uniform, causing fluid leakage and problems such as premature wear of the shaft seal member. Therefore, improvement of the shaft sealing method, response to shaft runout, etc. are being studied.
[0003]
As a conventional structure, for example, there is known a rotating device for the purpose of preventing leakage of contents and ensuring airtightness by using first and second sealing devices. In this structure, a sliding ring is used between the first and second sealing devices, and a structure that can follow shaft runout is provided by using a tightening structure described below.
[0004]
The followable structure (clamping structure) will be described with reference to FIG. 6. In the clamping structure 50, the screw shaft portion 51 and the clamping nut 52 are screwed together, and the flange 53 of the second sealing device is clamped. The compression spring coil 54 is fitted into the screw shaft portion between the attached nut 52. An insertion hole 55 is provided in the flange 53 of the sealing device 58, and the flange 53 is pressed through a sliding ring 56 so as to be slidable in the radial direction against the flange 57 of the first sealing device. In this device, when the rotary shaft 59 is displaced in the radial direction (the arrow direction in FIG. 6), a frictional force acts between the end surface of the flange 53 of the sealing device and the end surface of the spring 54 of the tightening structure 50, and the friction. Since the force acts in a direction that prevents the radial displacement of the sealing device 58, the sealing structure 58 cannot sufficiently follow, the pressing force between the shaft and the shaft sealing device becomes uneven, content leakage, shaft Premature wear of the seal member occurs. Further, when the seal device 58 is displaced in the radial direction (the arrow direction in FIG. 6) due to the shaft shake, the end surface of the spring 54 that contacts the end surface of the flange 53 of the seal device together with the flange 53 of the seal device is caused by the frictional force. Due to the displacement, the spring is biased in the radial direction, the spring pressing force becomes insufficient, the pressing force between the end faces of the sliding ring 56 and the main body 57 is insufficient, and the contents leak from between the end faces. Sometimes.
[0005]
[Problems to be solved by the invention]
Therefore, such a problem is eliminated, and it is possible to follow with high responsiveness to both axial and radial displacement due to shaft runout, there is no leakage of contents, and the spring force that forms the tightening structure There is a need for a shaft seal device that does not cause as much trouble as possible.
[0006]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems. According to the first invention, the rotating device and the seal box have a screw shaft through which an insertion hole provided in a flange of the seal box is inserted. And is coupled with a tightening structure in which a spring coil is interposed in a compressed state between the flange and a tightening nut threadedly engaged with a tip side portion of a screw shaft penetrating the flange and the rotary device; and A shaft seal device having a seal member presser for tightening a shaft seal member filled in a cylindrical seal space formed between the seal box and a rotating shaft,
A sliding ring is interposed between the seal box and the rotating device, and a sliding member is disposed between the flange of the seal box and the spring coil of the clamping structure. A shaft seal device is provided.
[0007]
Further, according to the second invention, a first sealing device and a second sealing device are disposed in order from the rotating device main body, and the first sealing device includes a first sealing box, a rotating shaft, and the first sealing box. A first shaft seal member press for clamping a shaft seal member filled in a cylindrical seal space formed between them from the atmosphere region side, and the second seal device includes a second seal box, A shaft seal member filled in a cylindrical seal space formed between the rotating shaft and the second seal box is configured from a second shaft seal member press for clamping from the atmosphere region side,
The first seal device and the second seal device are configured such that a screw shaft through which an insertion hole provided in a flange of the second seal box is inserted is screwed to the flange of the first seal box and the second seal is provided. A shaft seal device connected by a tightening structure in which a spring coil is interposed in a compressed state between a flange of a box and a tightening nut screwed to a tip side portion of a screw shaft passing through the box,
A sliding ring is interposed between the first seal device and the second seal device, and a sliding member is disposed between the flange of the two seal box and the spring coil of the clamping structure. A shaft seal device is provided.
[0008]
Further, according to the third aspect of the present invention, a cylindrical seal space formed between the rotary shaft and the first seal member press, the seal box, and the second seal member press in order from the rotating device main body is provided. It has a structure that fills and seals the shaft seal member,
The first seal member presser and the seal box are formed by screwing a screw shaft through which an insertion hole provided in the flange of the seal box is inserted into the first seal member presser and the flange of the seal box. A shaft seal device connected by a tightening structure in which a spring coil is interposed in a compressed state between a tightening nut screwed into a tip side portion of a threaded shaft that has penetrated,
A shaft seal device is provided, wherein a sliding member is disposed between the flange of the seal box and the spring coil of the tightening structure.
[0009]
In a preferred embodiment of each invention, the sliding member comprises at least three rolling elements on a circumference and a holding member for holding the rolling element, and the rolling element is slidably in contact with the flange.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The apparatus of the present invention is a shaft seal device having a tightening structure for inserting a seal device flange into a rotary device main body or another seal device so that the seal device can be relatively displaced in the axial direction and the radial direction of the rotation shaft. In particular, the apparatus is capable of following a displacement in the radial direction such as a shaft runout, has no leakage of contents, and has been improved so as to keep the packing tightening force stable even during the shaft runout.
[0011]
First, the fastening structure 10 used in the apparatus of the present invention will be described, and then the characteristic part of the present invention will be described.
As shown in FIG. 1, the tightening structure 10 is configured to screw a screw shaft 11 through which an insertion hole 15 provided in a flange 13 of a sealing device 18 is inserted into a rotary device main body 17 and to penetrate the flange 13 and the screw shaft 11. In this structure, a spring coil, preferably a compression spring coil 14, is interposed between the tightening nut 12 screwed into the distal end portion of the screw shaft 11. Preferably, the compression spring coil 14 is covered with a bottomed cylindrical body 28 (hereinafter also referred to as a collar) interposed in the screw shaft 11. By providing the collar 28, the spring coil 14 extends beyond the axial length of the collar when the tightening pressure is eased as the gland packing or the like, which is a shaft seal member, wears. The effect of giving an indication of tightening can be obtained.
[0012]
A feature of the device of the present invention is that between the components of the clamping structure 10 (compression spring coil 14, preferably the compression spring coil 14 is covered with a collar 28) and the flange 13 of the sealing device 18. The sliding member 20 is arranged so that the sliding member 20 contacts the flange 13. With such a configuration, the frictional force of the contact surface between the component part of the tightening structure 10 and the flange 13 of the sealing device 18 is reduced, and the sealing device 18 particularly has a shaft shake or the like with respect to the rotating device body 17. Since there is no decrease in the pressing force of the sliding ring 16 to the device body 17 due to the occurrence of partial distortion of the compression spring coil 14, there is no leakage of the contents. In addition, there is an effect that the packing tightening force is kept stable even when the shaft is shaken. Further, by providing the collar, it is possible to more effectively prevent the partial distortion of the compression spring coil 14.
[0013]
The sliding member 20 used in the apparatus of the present invention is roughly divided into two types, a rolling element and a sliding element. The rolling element is mainly a spherical body. In order for the rolling element made of a spherical body to function as a stable sliding member, at least three spherical bodies are arranged at almost equal intervals (for example, spacers). It is only necessary that they are arranged on the periphery of the through-hole of the flange 13 of the sealing device. The number of spherical bodies may be increased, and the spherical bodies may be arranged densely so as to contact each other in a circumferential shape. The spherical body used for the rolling element is preferably a true sphere, but may not necessarily be a true sphere, and may be a cylindrical body. The spacer (cage) partially surrounds the rolling element and moves together with the rolling element. The spacer serves to hold the rolling elements to the sliding member by placing the rolling elements at an appropriate interval and usually guiding them. Instead of the spacer, one separator may be placed between the two rolling elements to move with the rolling elements. As a specific sliding member, as illustrated in FIG. 2, a structure in which one side of the outer ring or inner ring of a single type thrust ball bearing is removed, that is, at least three or more balls and at least a part of those balls are included. The ring structure includes a spacer that can roll the spheres in an exposed state and holds the spheres at equal intervals, and a holding member that holds the spacers and the spheres. The back surface of the holding member is a flat surface. The sliding surface (spherical body portion) of such a sliding member is configured to slidably contact with the flange, and the component (compression spring coil and / or collar) of the clamping structure is configured to contact the back surface of the holding member. ing.
[0014]
Examples of the sliding body include a slide bearing in which a filler is mixed with a fluororesin having a small coefficient of friction and formed into a ring shape. As the fluororesin, for example, resins generally used by those skilled in the art, such as tetrafluoroethylene resin (PTFA) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA), are preferably used. A sliding body, such as a slide bearing, is used so that its smooth surface is in contact with the flange. Therefore, it is preferable that the flange is formed of a smooth surface, for example, a slide bearing.
[0015]
In the present invention, the seal box refers to a structure for pressing a shaft seal member such as a staffin box or a packing box, and the shaft seal member refers to a member such as a gland packing or a labyrinth seal. Means an apparatus including these seal box, shaft seal member, and seal member presser for clamping the shaft seal member.
[0016]
[Action]
In the shaft seal device of the present invention, as shown in FIG. 1, the sliding member 20 is disposed between the flange 13 and the compression spring coil 14 of the tightening structure 10, and therefore, between the flange 13 and the spring 14. The frictional force can be greatly reduced, whereby the sealing device 18 is easily displaced following the displacement of the rotating shaft 19 and the radial displacement followability is increased. Further, the partial distortion of the spring coil 14 is not generated, and the axial tightening pressure can be kept constant.
[0017]
【Example】
Hereinafter, the present invention will be described based on examples. In the following, the tightening structure refers to a tightening structure in which a compression spring coil is inserted into a screw shaft portion between the flange and the tightening nut unless otherwise specified.
[0018]
(Example 1)
In the shaft seal device (FIG. 3) of the first embodiment, the rotary device main body 17 and the packing box 31 a that is a seal box are connected by the first tightening structure 30 with the sliding ring 16 interposed therebetween. The first tightening structure 30 is configured such that a screw shaft 11 through which an insertion hole 15 provided in a flange 31b of a packing box 31a is inserted is screwed to a rotary device 17, and the flange 31b and the tip of the screw shaft 11 penetrating through the flange 31b. The sliding member 20 and the compression spring coil 14 are interposed so as to come into contact with the surface of the flange 31b between the tightening nut 12 screwed to the side portion. The first tightening structure 30 includes a bottomed cylindrical body (collar) 28 that houses a spring between the nut and the sliding portion. As shown in FIG. 2, the sliding member 20 is composed of a ring structure in which at least three spheres are arranged on the circumference at equal intervals. The spheres are in contact with the surface of the flange 31b. On the flat surface (back surface), the end surface of the collar 28 and / or the end surface of the compression spring coil 14 are pressed. And the gland packing 23 which is a shaft seal member filled in the cylindrical seal space formed between the packing box 31a and the rotary shaft 19 is provided with a packing presser 32a (seal member presser) with a second tightening structure. The structure is clamped by tightening at 34. The second tightening structure 34 and the first tightening structure 30 are the same except that the sliding member 20 is interposed in the first tightening structure 30.
[0019]
By having such a structure, the packing box can be displaced quickly and sufficiently in the radial direction, so the followability due to shaft runout is high, and this prevents the pressing force between the shaft and the packing from becoming uneven. Can maintain a proper seal. Furthermore, since the pressing force of each compression spring coil 14 does not generally weaken due to the bias distortion of the spring coil, and the pressing force of each compression spring coil does not vary, the packing box is pressed by the sliding ring 16. The load will not be uneven. Therefore, the contents or purge gas does not leak from between the end face of the sliding ring 16 and the flange end face of the rotating device 17.
[0020]
(Example 2)
FIG. 4 shows a shaft seal device according to Embodiment 2 of the present invention. In this shaft seal device, a first seal device 48 and a second seal device 48 are arranged in order from the rotary device main body 17. The first sealing device 48 includes a first packing box 36a and a first packing for clamping a gland packing 23a filled in a cylindrical seal space formed between the rotary shaft 19 and the first packing box 36a. It consists of a presser 37a. The flange 36b of the first packing box 36a of the first sealing device is coupled to the rotary device body 17, and the other flange 36c of the first packing box 36a and the flange 37b of the first packing presser 37a are: The gland packing 23a is clamped by being tightened via the first tightening structure 40.
[0021]
The second sealing device 49 includes a second packing box 38a and a second packing for clamping the gland packing 23b filled in a cylindrical seal space formed between the rotary shaft 19 and the second packing box 38a. It consists of a presser 39a. And the flange 38c of the 2nd packing box 38a and the flange 39b of the 2nd packing presser 39a are clamped via the 2nd clamping structure 41, and are pinching the gland packing 23b.
[0022]
In the shaft seal device according to the second embodiment, the third fastening structure 42 is fixed with the sliding ring 16 interposed. In the third tightening structure 42, the screw shaft 11 through which the insertion hole 15 provided in the flange 38c of the second packing box 38a is inserted is screwed to the rotating device 17, and the flange 38c and the screw shaft 11 passing through the flange 38c are inserted. The sliding member 20 and the compression spring coil 14 are interposed so as to be in contact with the surface of the flange 31b between the tightening nut 12 screwed to the tip end portion of the flange 31b. The third tightening structure 42 includes a bottomed cylindrical body (color) 28. As shown in FIG. 2, the sliding member 20 is composed of a ring structure in which at least three spheres are arranged on the circumference at equal intervals. The spheres are in contact with the surface of the flange 31b. On the flat surface (back surface), the end surface of the collar 28 and / or the end surface of the compression spring coil 14 are pressed.
[0023]
The first tightening structure 40 and the second tightening structure 41 are the same structure except that the sliding member 20 is interposed in the third tightening structure 42.
[0024]
By having such a structure, the packing box can be displaced quickly and sufficiently in the radial direction, so the followability due to shaft runout is high, and this prevents the pressing force between the shaft and the packing from becoming uneven. Can maintain a proper seal. Furthermore, since the pressing force of each compression spring coil 14 does not generally weaken and the pressing force of each compression spring coil does not vary, the load that the sliding ring 16 presses the packing box becomes non-uniform. There is no. Therefore, the contents or purge gas does not leak from between the end face of the sliding ring 16 and the flange end face of the rotating device 17.
[0025]
The shaft seal device of the second embodiment is preferably provided with a sealing gas supply means 43, and the purge pressure of the sealing gas is preferably adjusted to be higher by about 0.05 to 0.1 MPa than the pressure of the contents. If the pressure is less than 0.05 MPa, the effect of preventing the content from entering does not increase. If the pressure exceeds 0.1 MPa, in addition to the tightening pressure of the gland packing 23, an excessive seal pressure acts on the gland packing 23. The pressure between the shaft and the outer diameter of the shaft becomes too high, causing abnormal sliding and leakage of contents, and purge gas leaks from between the sliding ring end surface and the flange in sliding contact with it. .
[0026]
As shown in FIG. 4, the sealing gas is preferably purged by mounting the lantern ring 44 in the second packing box 38 a and providing the sealing gas recovery means 45. Examples of the sealing gas recovery means 45 include appropriate means for providing a leak hole and recovering the toxic gas and the seal gas leaked from the inside of the rotating body device. If the sealing gas containing these toxic gases is released to the atmosphere side, there is a risk of adversely affecting the health of the worker.
[0027]
Furthermore, as a preferred embodiment, in the shaft seal device of the second embodiment, a jack bolt 46 is provided on a flange 36b in contact with the rotating device main body 17 of the first packing box 36a. The jack bolt 46 is used for flange centering. Since the jack bolt 46 can adjust the centering between the casing and the first packing box 36a, the gland packing 23a can be smoothly mounted on the rotating shaft 19, and the gland packing 23a to be mounted can be smoothly mounted. Since it can be tightened uniformly between the circumference and the outer circumference of the rotating shaft 19, so-called one-sided contact can be prevented, avoiding the situation where the parts that are strongly hit are severely worn and the parts that are weakly hit are leaked. It is done.
[0028]
Further, as another preferred embodiment, it is preferable to provide the cooling means 47 on the outer peripheral side of the first packing box 36a. When the flange 36b is exposed to a high temperature due to a temperature rise caused by sliding contact between the gland packing 23a and the rotating shaft 19, or due to heat in the rotating device body, the flange 36b is thermally expanded or contracted. As a result, the pressure acting on the gland packing 23a varies. In such a situation, the sliding state under excessive pressure results in abnormal wear of the rotating shaft 19 or a decrease in sealing performance due to insufficient pressure. Various problems caused by the sliding contact heat or the heat in the rotating device are solved by providing the cooling means 47 on the outer peripheral side of the first packing box 36a.
[0029]
(Example 3)
A shaft seal device according to Embodiment 3 of the present invention will be described with reference to FIG. The apparatus according to the third embodiment includes a first packing holder 24 a, a staffin box 21 a, and a second packing holder 25 a in order from the rotary device body 17, and a cylindrical shape formed between these and the rotary shaft 19. The seal space is filled with a gland packing 23 and clamped.
[0030]
In the shaft seal device according to the third embodiment, the flange 24b of the first packing presser 24a and the flange 21b of the staffin box 21a are fixed to each other via the tightening structure 10. In this tightening structure 10, a screw shaft 11 through which an insertion hole 15 provided in a flange 21b of a staffin box 21a is inserted is screwed into a flange 24b of a first packing presser 24a, and a flange 21b and a screw passing through the flange 21b are screwed. The sliding member 20 and the compression spring coil 14 are interposed so as to contact the surface of the flange 21b between the fastening nut 12 screwed into the tip end portion of the shaft 11. The tightening structure 10 includes a bottomed cylindrical body (color) 28. As shown in FIG. 2, the sliding member 20 is composed of a ring structure in which at least three spheres are arranged on the circumference at equal intervals. The spheres are in contact with the surface of the flange 31b. On the flat surface (back surface), the end surface of the collar 28 and / or the end surface of the compression spring coil 14 are pressed.
[0031]
By having such a structure, the staffin box can be displaced quickly and sufficiently in the radial direction, so that followability due to shaft runout is high, and this may cause uneven pressing force between the shaft and the packing. And maintain a proper seal. Furthermore, since the pressing force of each compression spring coil does not weaken as a whole, and the pressing force of each compression spring coil does not vary, the load that presses the staffin box against the packing presser (on the equipment flange side) is uneven. It will never be. Accordingly, the tightening pressure on the packing does not decrease or vary, and a stable seal can be maintained for a long time.
[0032]
【The invention's effect】
The shaft seal device of the present invention has a tightening structure having a structure in which a frictional force generated by the flange end surface and the spring end surface of the seal device is reduced by interposing a sliding member between the flange end surface and the spring end surface of the seal device. Therefore, the followability to the radial displacement is particularly excellent. Further, since the gland packing is kept stable even when the shaft is shaken, the contents can be prevented from leaking.
[Brief description of the drawings]
FIG. 1 is a view showing a tightening structure used in a shaft seal device of the present invention.
FIG. 2 is a schematic view showing a rolling element as one of sliding members used in the present invention.
FIG. 3 is a schematic view showing a shaft seal device according to Embodiment 1 of the present invention.
FIG. 4 is a schematic view showing a shaft seal device according to Embodiment 2 of the present invention.
FIG. 5 is a schematic diagram showing a shaft seal device according to Embodiment 3 of the present invention.
FIG. 6 is a schematic view showing a tightening structure used in a conventional shaft seal device.
[Explanation of symbols]
10, 50 Tightening structure 11, 51 Screw shaft portion 12, 52 Tightening nut 13, 53, 57 Flange 14, 54 Compression spring coil 20, Sliding member 18, 58 Sealing device 15, 55 Insertion hole 16, 56 Sliding ring 17 Rotating equipment body 19 59 Rotating shaft 21a Stuffing box 21b Stuffing box flange 21c Stuffing box flange 22 Sealing space 23, 23a, 23b Gland packing 24a First packing presser 24b First packing presser flange 25a Second packing Presser 25b Second packing presser flange 26 O-ring 28 Bottomed cylinder (color)
30 First tightening structure 31a Packing box 31b Packing box flange 32a Packing retainer 33, 44 Lantern ring 34 Second tightening structure 36a First packing box 36b First packing box flange 36c First packing box flange 37a First Packing retainer 37b First packing retainer flange 38a Second packing box 38c Second packing box flange 39a Second packing retainer 39b Second packing retainer flange 40 First tightening structure 41 Second tightening structure 42 Third tightening Structure 43 Sealing gas supply means 45 Sealing gas recovery means 46 Jack bolt 47 Cooling means 48 First sealing device 49 Second sealing device

Claims (4)

The rotating device and the seal box are screwed into the rotating device with a screw shaft through which an insertion hole provided in the flange of the seal box is inserted, and screwed into the flange and the tip side portion of the screw shaft passing through the flange. A shaft that is connected to a tightened nut with a spring coil in a compressed state and is filled in a cylindrical seal space formed between the seal box and the rotary shaft A shaft seal device having a seal member press for tightening the seal member,
A sliding ring is interposed between the seal box and the rotating device, and a sliding member is disposed between the flange of the seal box and the spring coil of the clamping structure. Shaft seal device. A first sealing device and a second sealing device are arranged in order from the rotating device main body, and the first sealing device is a cylindrical shape formed between the first seal box, the rotating shaft, and the first seal box. The shaft seal member filled in the seal space is composed of a first shaft seal member presser for clamping the shaft seal member from the atmosphere region side, and the second seal device includes a second seal box, the rotating shaft, and the second seal. A shaft seal member filled in a cylindrical seal space formed between the box and a second shaft seal member press for pressing from the atmosphere region side,
The first seal device and the second seal device are configured such that a screw shaft through which an insertion hole provided in a flange of the second seal box is inserted is screwed to the flange of the first seal box and the second seal is provided. A shaft seal device connected by a tightening structure in which a spring coil is interposed in a compressed state between a flange of a box and a tightening nut screwed to a tip side portion of a screw shaft passing through the box,
A sliding ring is interposed between the first seal device and the second seal device, and a sliding member is disposed between the flange of the two seal box and the spring coil of the clamping structure. A shaft seal device. The rotary device main body has a first seal member presser, a seal box, and a second seal member presser in order, and a cylindrical seal space formed between these and the rotary shaft is filled with the shaft seal member and sandwiched. Has a structure to press,
The first seal member presser and the seal box are formed by screwing a screw shaft through which an insertion hole provided in the flange of the seal box is inserted into the first seal member presser and the flange of the seal box. A shaft seal device connected by a tightening structure in which a spring coil is interposed in a compressed state between a tightening nut screwed into a tip side portion of a threaded shaft that has penetrated,
A shaft seal device, wherein a sliding member is disposed between the flange of the seal box and the spring coil of the tightening structure. The sliding member comprises at least three rolling elements on a circumference and a holding member that holds the rolling element, and the rolling element is slidably in contact with the flange. The shaft seal device according to item.

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