JP2009250378A - Mechanical seal device for liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanical seal device for liquid capable of preventing the wear of a seal surface even if a lubricating liquid runs short at the seal surface of a seal ring. <P>SOLUTION: This mechanical seal device has: a dimple 3 which makes a sealed fluid flow into or flow out of a seal surface 2A of a fixed seal ring or an opposite seal surface 12A of a rotating seal ring and generates dynamic pressure between the seal surface 2A and the opposite seal surface 12A; a diffusion groove 2D formed into a longitudinal groove or an annular groove in the circumferential direction in a position of the seal surface 2A on the radial opposite side of the sealed fluid of the dimple 3; and a fluid passage 20 passing through the diffusion groove 2D so that gas or liquid flows therein. Gas or liquid is supplied between the seal surface 2A and the opposite seal surface 12A from a supply opening through the fluid passage 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mechanical seal device for liquid. More specifically, the present invention relates to a shaft seal mechanical seal device for a pump, a shaft seal mechanical seal device for a hydroelectric power generation turbine, or a turbine shaft seal mechanical seal device.

  A conventional mechanical seal device according to the present invention is used for a pump, a turbine, or the like. In particular, in a pump or a turbine, the sealed fluid to be sealed may be water. In this mechanical seal device for shaft sealing, although not shown in the drawing, the sealing surface of the sealing ring for fixing that is hermetically held by the housing and the opposing sealing surface of the sealing ring for rotation that is hermetically held by the rotating shaft are in close contact with each other. Thus, the sealed water present on the outer peripheral side of the sealing surface is sealed. Since this water contains impurities, the sealing ring is made of a hard carbon or silicon carbide material so that the sealing surface is not damaged. While the water is sealed, the water is interposed between the sealing surfaces, so that the sealing surface is lubricated by the water and does not generate heat by sliding, and the sealed liquid can be sealed.

  However, in a pump or a water wheel, since the sealed water is natural water, it is often not introduced into the pump or the water wheel. In this case, since water does not intervene between the seal surfaces, both the seal surfaces are hard and thus wear rapidly because they generate high temperatures due to sliding heat generation. And since a clearance gap arises between seal surfaces by abrasion, a sealing capability is reduced. In particular, since mechanical seal devices such as pumps and water wheels are large, the diameter of the circular seal surface is increased, so that the peripheral speed is also increased. As a result, when the sealing surface loses its lubricating action, sliding heat generation on the sealing surface becomes intense and the sealing surface is worn rapidly. Further, since the seal ring made of silicon carbide or carbon material is expensive, if the seal ring is worn and damaged, the cost of the seal ring for replacement increases. Even if the liquid introduction groove communicating with the sealed fluid side is provided on the sealing surface, it is difficult to prevent the sealing surface from being worn in a state where the sealed liquid is withered.

Furthermore, as another conventional mechanical seal device, there is a seal surface of the mechanical seal device shown in FIG. 8 (see, for example, FIG. 6 of Patent Document 1 and FIG. 2 of Patent Document 2). A number of L-shaped grooves 105 are formed along the peripheral surface of the seal surface 104 of FIG. 8 corresponding to FIG. 6 of Patent Document 1. The L-shaped groove 105 includes a gas introduction groove 105A and a dynamic pressure generation unit 105B. The depth of the L-shaped groove 105 is 15 × 10 ⁻⁶ m or less (see the paragraph number 0023 in the same specification). The depth of the L-shaped groove 105 generates a dynamic pressure with respect to the gas (see paragraph number 0001 in the same specification). Since the dynamic pressure generating groove for gas is a gas, the sealing surfaces do not have a lubricating action, so that the sealing surfaces are not contacted to prevent seizure or the like. Furthermore, the depth of the groove | channel of patent document 2 is 2.5 * 10 <^-6> m or less (refer the column of the Example of the specification). The shaft hermetic sealing device of Patent Document 2 is also a gas mechanical seal device (see the title of the invention and examples in the specification). From the above, it is found that all the dynamic pressure generating grooves provided on the seal surface are used for the gas mechanical seal device.

JP-A-07-260009, U.S. Pat. No. 5,092,612.

  The present invention has been made in view of the above-described problems, and the technical problem to be solved by the invention is that the heat generation of the seal surface of the mechanical seal device and the seizure / wear of the seal surface are caused. It is to prevent. Another object is to prevent the sealing surfaces from being damaged by the entry of impurities between the sealing surfaces. Furthermore, it is in improving the sealing capability of a sealing surface. At the same time, it is to improve the durability of an expensive seal ring such as silicon carbide and reduce the cost of the seal ring.

The present invention has been made to solve the technical problems as described above,
The technical solution is configured as follows.

A mechanical seal device according to a first aspect of the present invention is a mechanical seal device that shuts off a sealed liquid side and a gas side of a gap around a rotary shaft, and is for a shaft of a housing in which the rotary shaft is provided. A holding surface capable of being attached to an attachment surface surrounding the hole, an inner peripheral fitting surface around the rotating shaft, and a first passage penetrating from the one end on the fluid supply side to the inner peripheral fitting surface. An annular seal cover, an outer peripheral fitting surface that is movably fitted to the inner peripheral fitting surface of the seal cover, an inner peripheral surface that can be loosely coupled with the rotation shaft, and a joint end surface at one end surface A retainer having a flange portion provided with a second passage that communicates with the first passage and penetrates the joining end surface;
A fixed member having a first joint surface held in close contact with the joint end surface of the retainer, a seal surface provided on an end surface opposite to the first joint surface, and an inner peripheral surface capable of freely mating with the rotating shaft. A sealing ring for rotation, a sealing ring for rotation having a counter seal surface that is slidably in close contact with the sealing surface of the sealing ring for fixing, and fits with the rotating shaft, and seals the sealing ring for rotation A rotating side retainer that is held and fitted on the rotating shaft in a hermetically sealed manner is provided, and fluid to be sealed flows in and out of the sealing surface of the fixing sealing ring or the opposing sealing surface of the rotating sealing ring, and faces the sealing surface. A dimple for generating dynamic pressure between the sealing surfaces, and a diffusion groove formed in a longitudinal or annular groove in the circumferential direction at a position of the sealing surface opposite to the sealed fluid side of the dimple in the radial direction , The expansion A third passage that passes through the groove and communicates with the second passage and allows a gas or liquid to flow, and the liquid or gas passes through a fluid passage formed by the first passage, the second passage, and the third passage. It is supplied between the sealing surface and the opposing sealing surface.

  In the mechanical seal device of the present invention according to claim 2, the fluid passage is formed so as to penetrate both fitting surfaces of a retainer that holds the fixing sealing ring and a seal cover that is movably fitted to the retainer. It is what.

  In the mechanical seal device according to the first aspect of the present invention, when the rotary shaft is started, there is a case where no liquid is interposed between the seal surface and the opposed seal surface. In addition, there is a case where no liquid is interposed between the seal surface and the opposing seal surface when the rotation shaft finishes rotating. Furthermore, due to natural phenomena, the sealed fluid may not be interposed between the sealing surfaces. In such a situation, no liquid is interposed between the seal surface and the opposed seal surface, so that there is a risk that the seal surface will rapidly wear due to sliding heat generation. However, in the present invention, even in such a case, the liquid supplied from the fluid passage is interposed as a liquid film between the seal surfaces via the diffusion groove to prevent sliding heat generation. Further, the liquid film interposed between the sealing surfaces is pushed out to the sealed fluid side by dimples to prevent the sealed fluid from entering between the sealing surfaces, thereby exerting the sealing ability. Further, when there is a shortage of liquid from the fluid passage, the dynamic pressure generating force of the dimples on the seal surface brings the seal surfaces into a non-contact state, and there is an effect of preventing wear as well as sliding heat generation on the seal surface.

  In the mechanical seal device of the present invention according to claim 2, the retainer is movable, and the sealing ability is not improved unless the surface pressure of the seal surface is optimized with respect to the opposing seal surface. However, when the sliding action (outer peripheral face) of the retainer is not lubricated, the responsiveness of the surface pressure of the seal face is lowered and the sealing ability is also lowered. In the present invention, the fluid passage crosses the sliding surface of the retainer. At this time, the sliding surface is lubricated by the liquid passing through the fluid passage. As a result, the surface pressure response capability of the seal surface with respect to the opposing seal surface is improved, and the seal capability is exhibited. This effect can optimize the design of the spring means for pressing the retainer.

DESCRIPTION OF EMBODIMENTS Hereinafter, a mechanical seal device according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, the shape of each drawing demonstrated below was created based on the design drawing, and its dimensional relationship is accurate.

  FIG. 1 is a half sectional view of the upper side in the axial direction of a mechanical seal device 1 according to the present invention. The front view of FIG. 1 is an annular shape inserted into the rotating shaft 50. FIG. 2 is a half sectional view of the lower side of FIG. 3 is a one-side sectional view at a position of 90 degrees in the circumferential direction from the section of FIG. 3 is a one-side cross-sectional view at a position of 45 degrees from the position of the cross-section of FIG.

  FIGS. 1, 2 and 3 show a first embodiment (Example 1) according to the present invention, which shows a main part of a mechanical seal device 1 attached to a hydro turbine for hydroelectric power generation. is there. This will be described below with reference to FIGS. The rotating shaft 50 is inserted into the shaft hole 60A of the housing 60 and is rotatably supported. The symbol R of the housing 60 is the river water side outside the machine where the sealed fluid exists (sealed fluid side). Moreover, the code | symbol A side is the gas side in the machine, or the atmosphere side. The mechanical seal device 1 is provided to seal between the shaft hole 60 </ b> A of the housing 60 through which the rotating shaft 50 passes and the rotating shaft 50. The holding surface of the seal cover 30 with the reference numeral omitted is fastened to a mounting surface 60B surrounding the shaft hole 60A of the housing 60 by a bolt 61 via a sealing O-ring. The bolts 61 are provided at regular intervals along the circumferential surface, for example, at 16 locations. The number of the bolts 61 is large because the diameter of the seal cover 40 is about 1 m, but the number of the bolts 61 is set according to the diameter of the seal cover 40.

  The seal cover 40 has a first passage 20A that can supply a liquid (also referred to as a lubricating liquid) such as tap water that does not contain impurities or a gas when the liquid is cut off, from the pipe screw on the atmosphere side A to the inner peripheral fitting surface. It penetrates through 40A. Further, the protrusion 40E provided on the side surface 40B1 of the seal cover 40 is provided with a hole-shaped spring seat 40C. A plurality of the spring seats 40C are provided along the circumferential surface, for example, 15 locations and 20 locations according to the design. The seal cover 40 is configured as a two-part, three-part or four-part split seal cover so that the seal cover 40 can be attached by tying from both sides in the radial direction facing the rotating shaft 50. In FIG. 1, the divided seal cover is divided into two parts. Then, in order to connect each divided seal cover to the annular body so as to surround the rotating shaft 50, the connecting plates 40D are welded to both connecting surface sides (both ends) of the both side surfaces 40B1 and 40B2 of each divided seal cover. (See FIG. 3).

  Each connecting plate 40D provided in each divided seal cover is attached by welding so as to face each other in close proximity. Among the pair of connection plates 40D, 40D, one connection plate 40D is provided with a female screw, and the other connection plate 40D is provided with a through hole. Then, the bolt 45 is passed through the through hole and the bolt 45 is fastened to the female screw of one of the connecting plates 40D to form each divided seal cover on the annular seal cover 40. Note that when the diameter of the seal cover 40 is small or when the seal cover 40 can be easily inserted into the rotary shaft 50, it is not necessary to have a divided structure in which the seal cover 40 is divided into divided seal covers and connected to each other. That is, you may form in the seal cover 40 which comprises the integral annular | circular shape.

  The inner peripheral fitting surface 40A of the seal cover 40 is slidably fitted to the outer peripheral fitting surface 30A of the retainer 30. The retainer 30 is formed in a shape in which a flange portion 30B is provided at the end of the cylindrical body. The retainer 30 is provided with a first passage 20A penetrating from the one side surface 40B2 (one end portion for supplying a liquid or gas fluid) into the L-shaped inner peripheral fitting surface 40A. The inner circumferential fitting surface 40A side of the first passage 20A is formed in a groove having a width larger than the diameter of the first passage 20A in the axial direction. In addition, a second passage 20B is provided that communicates with the first passage 20A and has the other end in the axial direction penetrating the joint end surface of the flange portion 30B. A fitting surface communicating with the first passage 20A of the second passage 20B is formed in a groove having a width larger than the diameter of the second passage 20B in the axial direction symmetrical to the first passage 20A. The two grooves having a width in the axial direction are for allowing the first passage 20A and the second passage 20B to communicate with each other even if the retainer 30 moves by a minute distance in the axial direction.

  In addition, a joining end face (also simply referred to as an end face) of the flange portion 30B through which the second passage 20B passes is formed in a recess that surrounds the second passage 20B and is larger than the second passage 20B. The entirety of the first passage 20A and the second passage 20B is a fluid passage 20 for liquid or gas. Then, liquid or gas passing through the fluid passage 20 is formed on both sides where the first passage 20A and the second passage are connected between the outer peripheral fitting surface 30A of the retainer 30 and the inner peripheral fitting surface 40A of the seal cover 40. O-rings 21 and 21 for sealing are provided so as not to leak to the outside from between the fittings. The fluid passage 20 normally supplies a liquid, but when the liquid is insufficient due to a natural phenomenon (a water turbine for power generation in a mountainous area may cause a shortage of water due to a natural phenomenon), gas is pumped. This liquid pump can supply liquid or gas.

  Between the flange portion 30B of the retainer 30 and the spring seat 40C of the seal cover 40, spring means (coiled spring) 41 that pushes the flange portion 30B of the retainer 30 forward from the seal cover 40 is provided in the circumferential direction. The number of seats 40C is provided. In addition, the retainer 30 is loosely fitted on the inner peripheral surface with a clearance from the rotation shaft 50. Furthermore, the inner peripheral surface of the retainer 30 on the flange portion 30B side is formed as a stepped surface. The retainer 30 is also formed as a split retainer in the same manner as the seal cover 40. As shown in part A of FIG. 3, the tightening portion 30 </ b> C of the retainer 30 is a pair of two projecting plates that protrude in the radial direction, and connects the two tightening plates to each other. The split retainer is joined to the annular body by tightening the hexagon socket head cap screw 46 and the socket bolt 47. A pair of clamping plates of the retainer 30 is provided by the number of divisions of the division retainer. The retainer 30 can also be formed in an integral annular shape without being configured as a split retainer when the diameter is small or when the structure can be easily inserted into the rotary shaft 50.

  The first holder 35 is coupled to the flange portion 30 </ b> B of the retainer 30 in the axial direction by a hexagon socket bolt 46. The first holder 35 is also divided in the same manner as the retainer 30, and a first fastening plate 35 </ b> A that protrudes in the radial direction is provided on the outer periphery on each coupling surface side of each divided holder. The pair of first fastening plates 35 </ b> A and 35 </ b> A at two places in the circumferential direction are fastened in the same manner as the retainer 30. The first holder 35 provided with a pair of first fastening plates 35A, 35A is configured to hold the divided fixing sealing ring (hereinafter also referred to as a fixed sealing ring) 2 in an annular shape so as not to move in the axial direction. It is.

  The fixed seal ring 2 is divided into two parts like the retainer 30 and has a cross section as shown in FIG. That is, the sealing surface 2A is provided on one end surface of the fixed sealing ring 2, and the first joint surface 2E is provided on the other end surface. The seal surface 2A is polished to a mirror finish. The third passage 20D penetrating in the axial direction of the fixed seal ring 2 is in close contact with the joining end surface of the retainer 30 and the first joint surface 2E of the fixed seal ring 2 so as to communicate with the second passage 20B. The close structure of both the parts forms a large concave portion surrounding the second passage 20B on the joining end face of the retainer 30, and an O-ring 23 for sealing is provided around the outer periphery of the concave portion to form the second passage 20B and the second passage 20B. The periphery of the gap between the communication with the three passages 20D is sealed. Further, the fixing pin 5 driven into the joining end surface of the retainer 30 is engaged with the engaging hole 2H provided in the first joining surface 2E of the stationary sealing ring 2 so that the stationary sealing ring 2 does not rotate in the circumferential direction. Hold on.

A tapered surface is provided on the first outer peripheral surface 2B of the fixed sealing ring 2. The first O-ring 22 for sealing is elastically deformed in a triangular shape between the tapered surface of the fixed sealing ring 2 and the stepped surface of the first holder 35 and is divided by the first holder 35. The fixed sealing ring 2 is held on the annular body. When the fixed sealing ring 2 is tightened by the first holder 35, it is preferable to sandwich the first spacer 34 therebetween. The fixed sealing ring 2 configured in this manner forms an L-shaped dimple 3 on the R side (outer peripheral side) of the sealed fluid (river water or river water becomes insufficient) on the seal surface 2A (others). (See FIG. 6 for the example of this). The dimple 3 is L-shaped and symmetrically arranged in the circumferential direction so as to form a pair of dimples 3 for both forward and reverse rotation. As an example, the fixed sealing ring 2 has a diameter of about 500 mm. Therefore, 12 pairs (24 pieces) of dimples 3, 3,... Are provided on the sealing surface 2A. The number of the dimples 3 is set in consideration of the size of the fixed sealing ring 2 and the pumping force. The plane width of the dimple 3 is preferably 5 mm to 25 mm, for example. The depth is preferably 15 × 10 ⁻⁶ m to 50 × 10 ⁻⁶ m. When the rotary seal ring 12 is rotated only in one direction, it is not necessary to form a pair of dimples, and the L shapes may be arranged in the same shape in the circumferential direction. The dimple 3 includes a fluid inflow / outflow groove 3A in the radial direction and a dynamic pressure generation groove 3B in the circumferential direction.

  The dimple 3 pumps the liquid supplied from the third passage 20 </ b> D to the outer peripheral side depending on the radial and circumferential lengths of the dimple 3. At the same time, it serves to introduce the fluid on the sealed fluid side R into the sealing surface. Since the dimple 3 is pumped by the dynamic pressure generating groove 3B, the circumferential length of the dynamic pressure generating groove 3B is larger than that in the case where gas is interposed in the seal surfaces 2A and 12A (as compared to the conventional technique). ), It is good to form short. Further, the inflow / outflow grooves 3A may be formed wider than the case where gas is interposed between the seal surfaces 2A and 12A. Furthermore, a long diffusion groove 2D in the circumferential direction is formed on the inner peripheral side of the dimple 3 (when the fluid to be sealed is on the first inner peripheral surface 2C side of the seal surface 2A, the diffusion groove 2D and the outlet of the fluid passage 20 are It becomes the outer peripheral side of the dimple 3). The depth of the diffusion groove 2 </ b> D is preferably deeper than the depth of the dimple 3. The exit of the third passage 20D is provided at substantially the center in the circumferential direction of the diffusion groove 2D.

  The third passage 20D penetrates in the axial direction of the fixed sealing ring 2. However, if the third passage 20D is inclined from the middle of the third passage 20D toward the sealed fluid side and toward the dimple 3, from 20 degrees to 50 degrees. good. The number of third passages 20D is four to twelve. The diffusion grooves 2D and the dimples 3 configured in this way form a liquid between the seal surfaces 2A and 12A with a liquid ejected from the third passage 20D to form a lubricating action, and the liquid lubricated by the dimples 3 Pumping to the sealed fluid side R prevents the sealed fluid from entering the seal surfaces 2A and 12A. At the same time, the fluid to be sealed is prevented from entering between the sealing surfaces 2A and 12A by the pumping action of the dimple 3, thereby exerting the sealing ability. At the same time, when the fluid to be sealed, which is natural water, is insufficient or when the water is cut off and does not intervene in the seal surfaces 2A and 12A, the liquid supplied from the fluid passage 20 is liquidated to the seal surface 2 by the dimple 3. Diffusion like a film prevents the seal surfaces 2A and 12A from being worn by a lubricating action. Further, the seal surfaces 2A and 12A are brought into a non-contact state between the seal surfaces 2A and 12A by the pressure generated by the dynamic pressure generating groove 3B to prevent damage to the seal surfaces 2A and 12A. The fixed sealing ring 2 is made of a wear-resistant material such as silicon carbide, carbon, ceramic, super steel or the like.

  The fixed sealing ring 2 shown in FIG. The fixed sealing ring 2 shown in FIG. 6 is a case where the diameter is small such as 100 mm to 300 mm. That is, this fixed sealing ring 2 is not divided. When the fixed seal ring 2 is divided, the space between the dimple 3 and the dimple 3 in contact with the ring is divided into two in the radial direction. The dimple 3 provided on the seal surface 2A shown in FIG. 6 is a case where the sealed fluid side R is on the outer peripheral side. The shape of the dimple 3 is not limited to the L shape, and may be any other shape as long as it allows the liquid to flow in and out and causes a pumping action or a dynamic pressure generating force. However, the depth of the groove of the dimple 3 is made deep unlike the case of the gas of the prior art. In addition, when the to-be-sealed fluid side R exists in the 1st internal peripheral surface 2C of the fixed sealing ring 2, it forms in the fixed sealing ring 2 as shown in FIG. In FIG. 7, the diffusion groove 2D is formed as an annular groove on the seal surface 2A, but can also be formed as an intermittent groove as shown in FIG. That is, the diffusion groove 2D of the fixed sealing ring 2 can form an annular groove, an intermittent groove, a groove meandering in the circumferential direction, etc., if the liquid to be lubricated is diffused to the seal surface 2A to form a liquid film. 7 having the same reference numerals as those in FIG. 6 have the same configuration. In FIG. 7, an example in which the fixed sealing ring 2 is not divided is described. However, the fixed sealing ring 2 may be divided into two or three in the radial direction according to the size of the fixed sealing ring 2.

  A rotational sealing ring (hereinafter also referred to as a rotational sealing ring) 12 is disposed at a position facing the fixed sealing ring 2. The cross-sectional shape of the rotary seal ring 12 is as shown in FIG. An opposing seal surface 12 </ b> A is provided on one end surface of the rotary seal ring 12. The opposed seal surface 12A is finished to be a mirror surface so as to be slidable with the seal surface 2A. A second joint surface 12E is provided on the end surface opposite to the opposing seal surface 12A in the axial direction. A second engagement hole 12H that engages with the drive pin 15 is provided in the second joint surface 12E of the rotary seal ring 12. The second outer peripheral surface 12B of the rotary seal ring 12 is formed in substantially the same shape as the first outer peripheral surface 2B of the fixed seal ring 2. Further, the second inner peripheral surface 12C is non-contact with the rotation shaft 50 provided with a gap. The rotary sealing ring 12 divided into the two parts is fastened to the annular body together with the second holders 36 and 36. Similarly to the first holder 36, the second holder 36 is provided with a second fastening plate 36A for each divided holder. Then, the fastening plates 36A and 36A facing each other are fastened with hexagon socket head bolts and socket bolts, and the rotary seal ring 12 is coupled to the annular body together with the second holder 36. The second O-ring 22 and the second spacer 34 are interposed between the rotary seal ring 12 and the second holder 36 in the same manner as the first O-ring and the first spacer 34.

  The rotation side retainer 31 is divided, and a third tightening plate 32A similar to the tightening plate 35A of the first holder 35 is provided on the outer surface of the rotation side retainer 31 on the divided surface side for each divided retainer. Then, the third clamping plate 32A is clamped by the hexagon socket head cap screw 46 to couple the rotation side retainer 31 to the annular body. At this time, the rotation side retainer 31 is fitted to the rotary shaft 50 via the sealing O-ring 25 and is joined to the rotary sealing ring 12 in a sealing manner via the sealing O-ring 24 (see FIG. 2). ). Further, the drive pin 15 that has been driven into and fitted into the hole of the rotation side retainer 31 engages with the second locking hole 12H of the rotation sealing ring 12 and is fixed so that both parts rotate (see FIG. 2). reference). Further, the second holder 36 and the rotation side retainer 31 are coupled by being tightened by a hexagon socket head cap screw 46.

  The clamp ring 37 on the sealed fluid side R from the rotation side retainer 31 is divided. Also in the divided clamp ring, a fourth fastening plate 37A similar to the first holder 35 is provided on the divided surface side of each divided clamp ring. In the same manner as the first holder 35, the clamp ring 37 is joined to the annular body by fastening the fourth fastening plate 37 </ b> A with the hexagon socket head cap bolt 46 and the socket bolt 47. At the same time, the key groove 37 </ b> B provided in the clamp ring 37 engages with the key 42 provided on the rotating shaft 50 and is fixed so as to rotate together with the rotating shaft 50. The clamp ring 37 and the rotating side retainer 31 are coupled in the axial direction by a hexagon socket head cap screw 46.

  The bypass passage 20C in FIG. 2 allows the liquid flowing from the fluid passage 20 through the bypass passage 20C to flow along the flow line F1 of the flow line shown in the figure so as to reach the outer peripheral side of both the seal surfaces 12A and 12A. And dust etc. are prevented from adhering to the sealing surfaces 2A and 12A. Part B of FIG. 3 shows another cross section of FIG. Moreover, the A part of FIG. 3 shows the cross section of a position 90 degrees different from FIG. In addition, the mechanical seal device 1 is configured to be easily inserted into a rotating shaft 50 that is divided into a plurality of portions in the circumferential direction and mounted on the machine. The mechanical seal device 1 includes the seal surfaces 2A and 12A. Even if each seal surface 2A, 12A is divided by the effect of the lubricating liquid from each of the dimples 3, 3... And the fluid passage 20, the sealing ability can be exhibited without any problem.

  The mechanical seal device 1 configured in this manner supplies and lubricates a lubricating liquid such as tap water flowing through the fluid passage 20 between the seal surfaces 2A and 12A. When the river water on the sealed fluid side R is insufficient due to a natural phenomenon, the seal surfaces 2A and 12A may slide and generate heat in a dry state. However, the lubricating liquid supplied from the fluid passage 20 Sliding heat generation of each sealing surface 2A, 12A is prevented. The lubricating action and sealing effect of the seal surfaces 2A and 12A are effectively exhibited by the dimple 3 as described above. At the same time, the lubricating liquid present on the seal surfaces 2A and 12A effectively prevents the sealed fluid including mud from entering the seal surfaces 2A and 12A by the pumping action of the dimple 3, thereby improving the sealing performance. Let Further, even when the supply of the lubricating liquid to the seal surfaces 2A and 12A is stopped due to a shortage of river water due to a natural phenomenon and due to a failure or the like, the dimple 3 generates dynamic pressure between the seal surfaces 2A and 12A to Sliding heat generation can be prevented by bringing the seal surfaces 2A and 12A into a non-contact state. If this sliding heat generation is prevented, seizure and damage caused on the seal surfaces 2A and 12A can be prevented. For this reason, if damage to the expensive seal rings 2 and 12 can be prevented, this damage prevention has a great effect of reducing the cost.

  Although the mechanical seal device 1 according to the first embodiment has been described with respect to the split mechanical seal device 1, the mechanical seal device 1 may be configured as an integrated mechanical seal device 1 depending on a device to be attached (such as a power generation turbine). In this case, the disassembled parts described above are integrated, and the fastening plates 32A, 35A, 36A, and 37A are not necessary.

  As described above, this mechanical seal device is useful as a shaft seal device for large liquids. In particular, since a large seal ring is expensive, it is useful as a mechanical seal device that prevents wear of the seal surface. Furthermore, the cost of the expensive seal ring can be reduced, which is useful.

It is sectional drawing of the one side of the mechanical seal apparatus concerning 1st Embodiment of this invention. It is a half sectional view of the mechanical seal apparatus which shows the other cross section of FIG. It is a whole sectional view of a mechanical seal device showing other sections of Drawing 1. It is a half sectional view of the fixed sealing ring shown in FIG. It is a half sectional view of the rotation sealing ring shown in FIG. It is a front view of the fixed sealing ring shown in FIG. It is a front view of the other fixed sealing ring concerning FIG. It is a front view of a part of a conventional fixed sealing ring.

Explanation of symbols

1 Mechanical seal device
2 Sealing ring for fixing (fixed sealing ring)
2A Seal surface
2B 1st outer peripheral surface
2C 1st inner peripheral surface
2D diffusion groove
2E 1st joint surface
3 dimples
3A Inflow / outflow groove
3B Dynamic pressure generating groove
5 Fixing pin
12 Rotating seal ring (Rotating seal ring)
12A Opposing seal surface
12B Second outer peripheral surface
12C 2nd inner peripheral surface
12E Second joint surface
12H Second locking hole
20 Fluid passage
20A 1st passage
20B 2nd passage
20C bypass passage
20D 3rd passage
22 1st O-ring, 2nd O-ring
23 O-ring
30 Retainer
30A outer peripheral mating surface
30B Flange
30C Tightening part
31 Rotating side retainer
32A 3rd clamping plate
34 1st spacer, 2nd spacer
35 First holder
35A clamping plate
36 Second holder
36A Second clamping plate
37 Clamp ring
37A 3rd clamping plate
37B Keyway
40 Seal cover
40A Inner peripheral mating surface
40B1 side
40B2 side
40C Spring seat
40D connecting plate
40E protrusion
45 volts
46 Hexagon socket head cap screw
47 Socket bolt
50 axis of rotation
60 housing
60A shaft hole
60B Mounting surface
61 volts
A Gas side (atmosphere side)
B Sealed fluid side (liquid side)

Claims (2)

A mechanical seal device that shuts off a sealed liquid side and a gas side of a gap around a rotating shaft,
A holding surface capable of being attached to a mounting surface surrounding a shaft hole of a housing in which the rotary shaft is provided, an inner peripheral fitting surface around the rotary shaft, and an inner periphery from one end on the fluid supply side An annular seal cover having a first passage penetrating the fitting surface;
An outer peripheral fitting surface that is movably fitted to the inner peripheral fitting surface of the seal cover, an inner peripheral surface that can be loosely coupled with the rotary shaft, and a flange portion that has a joint end surface on one end surface And a retainer having a second passage that communicates with the first passage and penetrates the joining end surface;
A fixed member having a first joint surface held in close contact with the joint end surface of the retainer, a seal surface provided on an end surface opposite to the first joint surface, and an inner peripheral surface capable of freely mating with the rotating shaft. Sealing ring,
One end of the sealing ring that is slidable and in close contact with the sealing surface of the sealing ring for fixing and that can be fitted to the rotating shaft, and the sealing ring for rotation that holds and rotates the sealing ring for rotation It has a rotating side retainer that fits hermetically on the shaft,
A dimple that causes fluid to flow into and out of the sealing surface of the sealing ring for fixing or the opposing sealing surface of the sealing ring for rotation and generates dynamic pressure between the sealing surface and the opposing sealing surface; A gas having a diffusion groove formed in a circumferential groove or an annular groove in the circumferential direction at a position opposite to the sealed fluid side in the radial direction, and penetrating into the diffusion groove and communicating with the second passage; A third passage through which liquid flows, and liquid or gas is supplied between the seal surface and the opposing seal surface through a fluid passage formed by the first passage, the second passage, and the third passage. A mechanical seal device.   2. The fluid passage according to claim 1, wherein the fluid passage is formed so as to penetrate both fitting surfaces of the retainer that holds the fixing sealing ring and a seal cover that is movably fitted to the retainer. Mechanical seal device.

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