Shaft seal device

Abstract

To realize a shaft sealing device that has a highly versatile weir structure and can appropriately guide the flushing fluid to the discharge channel. [Solution] The shaft sealing device includes an annular passage 64 formed in an annular shape along the inner circumferential surface of the case 1 at a position continuous with respect to the discharge passage 62 on the inside in the radial direction R, and a weir member 8 that changes the direction of the flushing fluid flowing circumferentially through the annular passage 64 to the outside in the radial direction R, thereby allowing the flushing fluid to flow along the discharge passage 62. The annular passage 64 is provided with a groove 641 that is cut out toward the outside in the axial direction L. The weir member 8 includes a fluid receiving portion 80 that receives the flushing fluid flowing through the annular passage 64, and a wide portion 81 that is continuous with the fluid receiving portion 80 and is formed to be wider than the fluid receiving portion 80. The wide portion 81 is configured to be able to engage with the groove 641.

Description

TECHNICAL FIELD

[0001] The present invention relates to a shaft sealing device including a casing, and a mechanical seal that penetrates into the casing and seals the periphery of a rotating shaft extending along the axial direction.

BACKGROUND ART

[0002] For example, Japanese Patent Laid-Open No. 2019-060497 (Patent Document 1) discloses a shaft sealing device for sealing the periphery of a rotating shaft in rotating equipment such as a pump. Such a shaft sealing device is intended to suppress fluid leakage.

[0003] As shown in Figure 7, in the shaft sealing device described in Patent Document 1, flushing fluid is supplied from a supply passage (106) to the in-machine region in order to cool the portion (near the sliding surface) that tends to reach a high temperature due to sliding between the rotating ring (104) and the stationary ring (102). After cooling the portion to be cooled, the flushing fluid is discharged from a discharge passage (107) to the out-of-machine region.

[0004] At a position adjacent to the discharge passage (107) on the inner side in the radial direction (R), an annular passage (108) formed in an annular shape is provided. A weir member (109) is provided in this annular passage (108). As shown in Figure 8 (a cross-sectional view taken along the line A-A in Figure 7), the weir member (109) is arranged in the annular passage (108) at a position slightly offset to the downstream side in the rotation direction of the pumping ring (105) relative to the discharge passage (107), that is, to the downstream side in the rotation direction of the rotating shaft (103).

[0005] As shown in Figure 7, the flushing fluid supplied to the machine interior from the supply passage (106) passes through the stationary ring (102) and the rotating ring (104), and is then guided to the annular passage (108) by the pumping ring (105). Then, as shown in Figure 8, the flushing fluid guided to the annular passage (108) flows through the annular passage (108) along the direction of rotation of the rotating shaft (103). This flow of flushing fluid along the direction of rotation is converted by the weir member (109) into a flow directed radially (R) outward. As a result, the flushing fluid is discharged to the machine exterior through the discharge passage (107). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-060497 [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, when attaching the weir member described above to the case, welding is sometimes used. This fixes the weir member within the annular passage formed in the case. As mentioned above, in order to guide the flushing fluid to the discharge passage, the weir member must be positioned downstream of the discharge passage in the direction of rotation of the rotating shaft. In other words, the position where the weir member should be installed relative to the annular passage depends on the direction of rotation of the rotating shaft. However, the direction of rotation of the rotating shaft is relative and changes depending on whether it is viewed from one side or the opposite side in the axial direction, and in some cases, the position of the weir member relative to the discharge passage may be reversed in the circumferential direction. However, as mentioned above, if the weir member is fixed to the case by welding or the like, it is difficult to flexibly meet such requirements.

[0008] In light of the above circumstances, there is a need for a shaft sealing device that can appropriately guide the flushing fluid to the discharge channel and has a highly versatile weir structure. [Means for solving the problem]

[0009] A shaft sealing device comprising a case and a mechanical seal that penetrates the case and seals the area around a rotating shaft that extends axially, A supply passage is formed in the case and supplies flushing fluid from the outside to the inside of the case, A discharge passage is formed in the case and discharges the flushing fluid from the inside of the case to the outside, An internal flow path within the case that serves as a flow path for the flushing fluid, A ring-shaped passage is formed along the inner circumferential surface of the case at a position continuous with respect to the discharge passage in the radial direction inward, The system comprises a weir member that changes the direction of the flushing fluid flowing circumferentially through the annular passage to the radially outward direction, thereby allowing the flushing fluid to flow along the discharge passage. The annular road is provided with a groove that is cut out toward the outward direction in the axial direction. The aforementioned weir member is, A fluid receiving section that receives the flushing fluid flowing through the annular passage, It comprises a wide portion that is continuous with the fluid receiving portion and is formed to be wider than the fluid receiving portion, The wide portion is configured to be able to engage with the groove.

[0010] According to this configuration, the weir member can be installed in the annular passage by engaging the wide portion of the weir member with the groove of the annular passage. Since the wide portion can freely engage with the groove, the weir member can be removed from the annular passage by releasing this engagement. In other words, according to this configuration, the weir member can be attached to and detached from the annular passage (case), and therefore, the mounting position of the weir member on the annular passage can also be changed. Thus, according to this configuration, a weir structure can be realized that not only has the main function of converting the flow of flushing fluid, but also possesses high versatility.

[0011] Further features and advantages of the technology according to the present disclosure will become clearer from the following description of exemplary and non-limiting embodiments described with reference to the drawings. Brief Description of the Drawings

[0012] [Figure 1] Cross-sectional view showing a shaft seal device [Figure 2] Perspective view of a weir member [Figure 3] Cross-sectional view showing the main part of the shaft seal device [Figure 4] Diagram showing the installation process of the weir member in the IV arrow direction of Fig. 3 [Figure 5] V-V cross-sectional view in Fig. 3 [Figure 6] Diagram showing the weir member applied to the opposite structure in the axial direction [Figure 7] Cross-sectional view showing a conventional shaft seal device [Figure 8] A-A cross-sectional view in Fig. 7 Modes for Carrying Out the Invention

[0013] Embodiments of the shaft seal device will be described with reference to the drawings.

[0014] As shown in Fig. 1, the shaft seal device 100 includes a case 1, and a mechanical seal 4 that penetrates into the case 1 and seals the periphery of the rotating shaft 2 extending along the axial direction. Such a shaft seal device 100 may be used, for example, in a pump for supplying water to a boiler of a thermal power plant.

[0015] In the following, the "axial direction L", "radial direction R", and "circumferential direction C" are defined with the axis Ax of the rotating shaft 2 as a reference. Further, one side in the axial direction L is defined as the "first axial side L1", and the other side is defined as the "second axial side L2".

[0016] Case 1 is formed in a cylindrical shape. In the present embodiment, the case 1 is configured by arranging a plurality of annular members side by side in the axial direction L and connecting them. However, without being limited to such a configuration, the case 1 may be configured as a single integral member.

[0017] The rotating shaft 2 penetrates through the case 1 and is connected to a rotational drive source (not shown) at an end portion in the axial direction L. Examples of the rotational drive source include an electric motor, an engine, and the like.

[0018] The mechanical seal 4 includes a stationary ring 41 fixed to the case 1 so as not to be rotatable, and a rotating ring 42 that rotates integrally with the rotating shaft 2.

[0019] The stationary ring 41 is a seal ring, and is configured to be movable in the axial direction L by being biased by a biasing member 53 held by a retainer 50. A spring can be exemplified as the biasing member 53. However, the biasing member 53 may also be configured using a bellows.

[0020] The rotating ring 42 is a mating ring whose position in the axial direction L is fixed. In the present embodiment, a sleeve 3 is provided on the outer peripheral surface of the rotating shaft 2, and the rotating ring 42 is held by the sleeve 3. In this example, the rotating ring 42 is disposed radially inward R of the cylindrical holding portion 32 of the sleeve 3, and is held at that position.

[0021] In the present embodiment, the stationary ring 41 is disposed on the first axial side L1 with respect to the rotating ring 42. The rotating ring 42 is disposed on the second axial side L2 with respect to the stationary ring 41. The surface of the stationary ring 41 facing the second axial side L2 and the surface of the rotating ring 42 facing the first axial side L1 face each other in the axial direction L. As the stationary ring 41 is biased toward the second axial side L2 by the biasing member 53, the mutually axially L facing surfaces of the stationary ring 41 and the rotating ring 42 slide against each other to form a seal surface S, thereby suppressing liquid leakage.

[0022] In the illustrated example, a retaining ring 51 is provided between the fixed ring 41 and the biasing member 53 in the axial direction L, to hold the fixed ring 41. The fixed ring 41 is configured to be biased by the biasing member 53 via the retaining ring 51.

[0023] Here, the sealing surface S where the surfaces of the stationary ring 41 and the rotating ring 42 slide against each other, and its surrounding areas, tend to become hot due to friction. Therefore, a flushing fluid is used to cool these areas. For example, the flushing fluid is the same fluid as the sealed fluid (boiler water).

[0024] The shaft sealing device 100 includes a case 1 formed therein, a supply passage 61 that supplies flushing fluid from the outside to the inside of the case 1, a discharge passage 62 formed in the case 1 that discharges the flushing fluid from the inside to the outside of the case 1, and an internal passage 63 that serves as a flow path for the flushing fluid within the case 1.

[0025] The flushing fluid is supplied from outside case 1 to the internal flow path 63 via the supply passage 61, and after cooling the target area, mainly the sealing surface S, it is discharged to the outside of case 1 via the discharge passage 62. Although not shown in the diagram, the high-temperature flushing fluid discharged from the discharge passage 62 is cooled by a cooler and supplied back into the machine via the supply passage 61. In other words, the flushing fluid is configured to cool the target area by repeatedly exchanging heat while circulating inside and outside the machine.

[0026] Thus, the flushing fluid flows in the order of supply passage 61, internal passage 63, and discharge passage 62.

[0027] The supply path 61 is formed to penetrate the case 1 in the radial direction R. The supply path 61 may be along the radial direction R, or it may be inclined with respect to the radial direction R. Alternatively, it may be composed of straight paths or curved paths.

[0028] The internal flow path 63 includes at least a fixed-side internal region 63b located on the first axial side L1 (opposite side from the rotating ring 42) of the fixed ring 41, a rotating-side internal region 63d located on the second axial side L2 (the side where the rotating ring 42 is located) of the fixed ring 41, and a fixed ring through-hole 63c that penetrates the fixed ring 41 in the axial direction L and connects the fixed-side internal region 63b and the rotating-side internal region 63d.

[0029] In this embodiment, the internal flow path 63 further includes an adapter ring through hole 63a. In this example, the shaft sealing device 100 includes an adapter ring 54 positioned radially R outward from the fixed ring 41. The adapter ring 54 is connected to the retainer 50. The adapter ring through hole 63a is a hole that penetrates a portion of the adapter ring 54 radially R, and connects the supply path 61 to the fixed-side internal region 63b.

[0030] In this embodiment, the flushing fluid supplied into the machine from the supply passage 61 is configured to flow sequentially through the adapter ring through-hole 63a, the fixed-side machine region 63b, the fixed ring through-hole 63c, and the rotating-side machine region 63d, which serve as the internal flow path 63. The flushing fluid then proceeds to the discharge passage 62.

[0031] In this embodiment, the shaft seal device 100 includes a pumping ring 55 for directing the flushing fluid in the internal region (rotating internal region 63d) into the discharge passage 62. The pumping ring 55 is configured to rotate integrally with the rotating shaft 2. In this example, the pumping ring 55 is positioned to cover the cylindrical holding portion 32 of the sleeve 3 from the outside in the radial direction R.

[0032] The pumping ring 55 is adjacent to the rotating side internal region 63d. The pumping ring 55 has an inclined surface 55a that slopes outward in the radial direction R as it progresses from the first axial side L1 to the second axial side L2. The flushing fluid in the rotating side internal region 63d flows outward in the radial direction R along the inclined surface 55a due to the rotation of the pumping ring 55.

[0033] The shaft seal device 100 includes an annular passage 64 formed in an annular shape along the inner circumferential surface of the case 1, at a position continuous with respect to the discharge passage 62 in the radial direction R. The flushing fluid is introduced from the rotating side machine internal region 63d into the annular passage 64 by the action of the pumping ring 55. The flushing fluid then flows through the annular passage 64 along the circumferential direction C in the same direction as the rotation direction CW of the pumping ring 55 (see also Figure 5).

[0034] The shaft seal device 100 is equipped with a weir member 8 that changes the direction of the flushing fluid flowing in the circumferential direction C through the annular passage 64 to the radial direction R outwards, and directs the flushing fluid along the discharge passage 62 (see also Figure 5). The flushing fluid flowing through the annular passage 64 has its direction changed by the weir member 8 to the radial direction R outwards, and is discharged outside the machine through the discharge passage 62.

[0035] The discharge passage 62 is formed to penetrate the case 1 in the radial direction R. The discharge passage 62 may be along the radial direction R, or it may be inclined with respect to the radial direction R. Alternatively, it may be composed of straight paths or curved paths.

[0036] Thus, the weir member 8 is provided in the annular passage 64 and has the function of changing the direction of the flushing fluid. Furthermore, the weir member 8 according to this disclosure is configured to be detachably attached to the annular passage 64. This makes it possible to change the position of the weir member 8 relative to the annular passage 64.

[0037] As will be explained in detail later, in order to change the direction of the flushing fluid flowing through the annular passage 64 to the same direction as the rotation direction of the pumping ring 55 (the rotation direction CW of the rotating shaft 2) and guide it to the discharge passage 62, the position where the weir member 8 should be installed must be downstream of the discharge passage 62 in the rotation direction CW (see also Figure 5). In other words, the position where the weir member 8 should be installed relative to the annular passage 64 depends not only on the position of the discharge passage 62 but also on the rotation direction CW of the rotating shaft 2. However, the rotation direction CW of the rotating shaft 2 is relative and changes depending on whether it is viewed from the first axial side L1 or the second axial side L2 (in the example shown in Figure 6, "CWW" is the rotation direction), and in some cases, the position of the weir member 8 may be required to be reversed in the circumferential direction C.

[0038] The weir member 8 according to this disclosure is detachable from the annular passage 64 and its position can be changed, thus meeting the above requirements. In other words, the weir member 8 can be positioned at an appropriate location that allows the flushing fluid to be guided to the discharge passage 62 depending on the situation. The weir structure of the shaft sealing device 100 according to this disclosure will be described in detail below.

[0039] As shown in Figure 2, the weir member 8 includes a fluid receiving section 80 that receives the flushing fluid flowing through the annular passage 64, and a wide section 81 that is continuous with the fluid receiving section 80 and is wider than the fluid receiving section 80.

[0040] In this embodiment, the fluid receiving portion 80 is a rectangular parallelepiped block. The wide portion 81 is formed in a plate shape. The fluid receiving portion 80 and the wide portion 81 are integrally formed using the same material. In this example, the weir member 8 has an insertion hole 83 into which a fastener 70, described later, is inserted. The insertion hole 83 is formed to penetrate both the wide portion 81 and the fluid receiving portion 80.

[0041] As described above, the wide portion 81 is formed in a plate-like, or rectangular, shape. Therefore, the wide portion 81 has a longitudinal extension portion 811 and a short extension portion 812 that is shorter than the longitudinal extension portion 811. The longitudinal extension portion 811 constitutes the long side of the rectangular wide portion 81, and the short extension portion 812 constitutes the short side of the rectangular wide portion 81.

[0042] As shown in Figure 3, the annular passage 64 is provided with a groove 641 that is cut outwards in the axial direction L. In this embodiment, the annular passage 64 comprises a main passage 640 through which the flushing fluid mainly flows, and a groove 641 formed continuously with respect to the main passage 640 in the radial direction R. The groove 641 is formed continuously with respect to the main passage 640 in the radial direction R. The groove 641 has a wider axial width L than the main passage 640.

[0043] The wide portion 81 of the weir member 8 is configured to be able to engage with the groove 641 of the annular passage 64. When the wide portion 81 engages with the groove 641, the weir member 8 is installed in the annular passage 64. Conversely, when the engagement of the wide portion 81 with the groove 641 is released, the weir member 8 is removed from the annular passage 64. In this way, the weir member 8 is detachably attached to and removed from the annular passage 64.

[0044] When the wide portion 81 is engaged with the groove 641 in the annular passage 64, the wide portion 81 is positioned to fill the groove 641, and the fluid receiving portion 80 is positioned to fill the main passage 640. "Positioned to fill" includes not only positioning without any gaps, but also positioning with a gap that is considered to be a design error.

[0045] As shown in Figure 2, in this embodiment, the outer end face 8f of the weir member 8 in the radial direction R is a curved surface that conforms to the shape of the annular passage 64. This allows the weir member 8 to be positioned in the annular passage 64 with no gap or with a very small gap.

[0046] Figure 4 shows how the weir member 8 is attached to the annular road 64.

[0047] As shown in Figure 4, the dimension 811L of the longitudinal extension 811 in the wide section 81 (see Figure 2) is larger than the axial dimension 640L of the part of the ring road 64 without groove 641 (main road 640), and smaller than the axial dimension 641L of groove 641 in the ring road 64. Furthermore, the dimension 812L of the short extension 812 in the wide section 81 (see Figure 2) is smaller than the axial dimension 640L of the part of the ring road 64 without groove 641 (main road 640).

[0048] Therefore, when attaching the weir member 8 to the annular passage 64, first, as shown by the dashed line in Figure 4, the weir member 8 is positioned inside the annular passage 64 with the longitudinal extension 811 of the wide portion 81 aligned with the circumferential direction C. In this state, the weir member 8 is rotated 90° so that the longitudinal extension 811 of the wide portion 81 is aligned with the axial direction L, as shown by the solid line in Figure 4. As a result, the wide portion 81 engages with the groove 641, and the weir member 8 is attached to the annular passage 64, resulting in the state shown in Figure 3. Note that when the wide portion 81 is engaged with the groove 641, the direction in which the insertion hole 83 extends will be along the radial direction R.

[0049] As shown in Figure 5, mounting positions 64S for the weir member 8 are set at positions adjacent to the discharge passage 62 on at least both sides in the circumferential direction C along the annular passage 64. A groove 641 is provided at each mounting position 64S, 64S. In this embodiment, the groove 641 is provided around the entire circumference of the annular passage 64. The portion of the groove 641 adjacent to the discharge passage 62 in the circumferential direction C is set as the mounting position 64S where the weir member 8 should be installed.

[0050] Here, if we define the direction of rotation of the rotating shaft 2 as the rotational direction CW, the weir member 8 is attached to the annular passage 64 at the mounting position 64S that is adjacent to the discharge passage 62 on the downstream side in the rotational direction CW. This makes it possible to change the direction of the flushing fluid flowing through the annular passage 64 in the rotational direction CW to the outside of the radial direction R and guide it to the discharge passage 62. Note that "CW" in Figure 5 indicates the rotational direction of the rotating shaft 2 when viewed from the axial first side L1.

[0051] In this embodiment, a circumferential fixing means 7 for fixing the weir member 8 in the circumferential direction C is provided at the mounting position 64S. The circumferential fixing means 7 is configured using a fastener 70 that presses the weir member 8 against the outer circumferential surface of the annular passage 64. A set screw can be exemplified as the fastener 70. The set screw, when inserted into the insertion hole 83 of the weir member 8, is in contact with the outer circumferential surface of the annular passage 64 from the inside in the radial direction R. However, the configuration is not limited to this, and for example, a through hole with an internal thread may be provided on the outer circumferential surface of the annular passage 64 at the mounting position 64S, and the weir member 8 may be fixed using a bolt that is screwed into this through hole.

[0052] The weir member 8 is fixed by the circumferential fixing means 7, so that it is not pushed even when subjected to pressure from the flushing fluid. Furthermore, when the rotation of the rotating shaft 2 stops, the flow of the flushing fluid also stops, and negative pressure may be generated inside the annular passage 64. When negative pressure is generated, the weir member 8 is subjected to a force acting in the opposite direction to the direction in which it was pushed by the flushing fluid. However, as in this configuration, because the weir member 8 is fixed by the circumferential fixing means 7, the weir member 8 can be kept in the appropriate position even when such negative pressure is generated.

[0053] Figure 5 illustrates the case where a weir member 8 is provided downstream of the discharge passage 62 in the rotation direction CW, based on the rotation direction CW of the rotating shaft 2 as viewed from the first axial side L1. However, even if the rotating shaft 2 is actually rotating in the same direction, it will appear reversed when viewed from the opposite side of the axial direction L (the second axial side L2).

[0054] Figure 6 shows the case in which the weir member 8 is installed based on the rotation direction of the rotation axis 2 (hereinafter referred to as "reverse direction CCW") as viewed from the second axial side L2.

[0055] In this case, the weir member 8 is attached to the annular passage 64 at the mounting position 64S that is adjacent to the discharge passage 62 on the downstream side in the reverse direction CCW among the mounting positions 64S, 64S. This makes it possible to change the direction of the flushing fluid flowing through the annular passage 64 in the reverse direction CCW to the outside of the radial direction R and guide it to the discharge passage 62.

[0056] Thus, in the shaft sealing device 100 according to this disclosure, the weir member 8 is detachably attached to the annular passage 64. Therefore, based on the direction in which the rotating shaft 2 rotates (the direction in which the flushing fluid flows) and the position of the discharge passage 62, it is possible to select an appropriate position to guide the flushing fluid flowing through the annular passage 64 to the discharge passage 62 and install the weir member 8 at that position.

[0057] Although detailed illustrations are omitted, the shaft sealing device 100 is provided along the same rotation axis 2 and includes a pair of mechanical seals 4 and a weir structure (discharge passage 62, annular passage 64, weir member 8) that are symmetrical with respect to each other in the axial direction L. According to the shaft sealing device 100 of this disclosure, the weir member 8 can be variably attached to the annular passage 64, so in order to achieve the symmetrical structure described above, it is sufficient to use two sets of the same member, and it is not necessary to use two different types of dedicated members.

[0058] [Other Embodiments] Next, other embodiments will be described.

[0059] (1) In the above embodiment, an example was described in which the groove 641 is provided around the entire circumference of the annular passage 64. However, the invention is not limited to such an example. The groove 641 only needs to be provided at the mounting position 64S of the weir member 8.

[0060] (2) In the above embodiment, an example was described in which a fastener 70 is used as the circumferential fixing means 7 for fixing the weir member 8 in the circumferential direction C. However, the invention is not limited to such an example. For example, the weir member 8 may be fixed in the circumferential direction C by making the portion of the weir member 8 that contacts the annular passage 64 have a high coefficient of friction. In other words, the weir member 8 itself may have the circumferential fixing means 7.

[0061] (3) In the above embodiment, an example was described in which the outer end face 8f of the weir member 8 in the radial direction R is a curved surface that follows the shape of the annular road 64. However, the embodiment is not limited to this example. The outer end face 8f of the weir member 8 in the radial direction R may be flat.

[0062] (4) The configurations disclosed in the embodiments described above can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. With regard to other configurations, the embodiments disclosed herein are merely illustrative in all respects. Therefore, various modifications can be made as appropriate without departing from the spirit of this disclosure.

[0063] [Summary of this embodiment] The following is a summary of this embodiment.

[0064] A shaft sealing device comprising a case and a mechanical seal that penetrates the case and seals the area around a rotating shaft that extends axially, A supply passage is formed in the case and supplies flushing fluid from the outside to the inside of the case, A discharge passage is formed in the case and discharges the flushing fluid from the inside of the case to the outside, An internal flow path within the case that serves as a flow path for the flushing fluid, A ring-shaped passage is formed along the inner circumferential surface of the case at a position continuous with respect to the discharge passage in the radial direction inward, The system comprises a weir member that changes the direction of the flushing fluid flowing circumferentially through the annular passage to the radially outward direction, thereby allowing the flushing fluid to flow along the discharge passage. The annular road is provided with a groove that is cut out toward the outward direction in the axial direction. The aforementioned weir member is, A fluid receiving section that receives the flushing fluid flowing through the annular passage, It comprises a wide portion that is continuous with the fluid receiving portion and is formed to be wider than the fluid receiving portion, The wide portion is configured to be able to engage with the groove.

[0065] According to this configuration, the weir member can be installed in the annular passage by engaging the wide portion of the weir member with the groove of the annular passage. Since the wide portion can freely engage with the groove, the weir member can be removed from the annular passage by releasing this engagement. In other words, according to this configuration, the weir member can be attached to and detached from the annular passage (case), and therefore, the mounting position of the weir member on the annular passage can also be changed. Thus, according to this configuration, a weir structure can be realized that not only has the main function of converting the flow of flushing fluid, but also possesses high versatility.

[0066] The wide portion has a longitudinally extended portion and a shorter longitudinally extended portion, The dimensions of the longitudinal extension are greater than the axial dimension of the portion of the annular road without the groove, and smaller than the axial dimension of the groove in the annular road. Preferably, the dimensions of the short-side extension are smaller than the axial dimensions of the portion of the annular road without the groove.

[0067] According to this configuration, when attaching the weir member to the annular road, the weir member is positioned within the annular road so that its longitudinally extended portion is aligned with the direction of extension of the annular road, and then the weir member is rotated so that its longitudinally extended portion is aligned with the width direction of the annular road, thereby engaging the wider portion with the groove. With this configuration, the weir member can be attached to the annular road through such a simple operation.

[0068] The mounting positions for the weir members are set at positions adjacent to the discharge passage on each of the circumferential sides in the annular passage, It is preferable that the grooves are provided at each mounting position.

[0069] With this configuration, the mounting position for the weir member can be selected in accordance with the direction in which the flushing fluid flows through the annular passage. Therefore, the weir member can be positioned at an appropriate location that can guide the flushing fluid to the discharge passage depending on the situation.

[0070] Preferably, the mounting position is provided with circumferential fixing means for fixing the weir member in the circumferential direction.

[0071] With this configuration, the weir member can be fixed in the circumferential direction within the annular passage, thereby preventing the weir member from shifting position due to being pushed by the flushing fluid flowing through the annular passage.

[0072] It is preferable that the radially outer end face of the weir member is a curved surface that conforms to the shape of the annular road.

[0073] This configuration makes it difficult for gaps to form between the annular passage and the weir member, and makes it easier to enhance the function of the weir member in converting the flow of the flushing fluid. [Industrial applicability]

[0074] The technology relating to this disclosure can be used in a shaft sealing device comprising a case and a mechanical seal that seals around a rotating shaft that penetrates the case and extends along the axial direction. [Explanation of Symbols]

[0075] 100: Shaft sealing device 1: Case 2: Rotation axis 4: Mechanical seal 7: Circumferential fixing means 8:Weir member 8f: End face 80: Fluid receiving section 81: Wide part 811:Longitudinal extension 812:Short extension part 61: Supply route 62:Exhaust channel 63: In-flight airflow path 64: Circular Road 64S: Mounting position 641: Groove C: Circumferential direction L: Axial direction R: Radial direction

Claims

1. A shaft sealing device comprising a case and a mechanical seal that penetrates the case and seals the area around a rotating shaft that extends axially, A supply passage is formed in the case and supplies flushing fluid from the outside to the inside of the case, A discharge passage is formed in the case and discharges the flushing fluid from the inside of the case to the outside, An internal flow path within the case that serves as a flow path for the flushing fluid, A ring-shaped passage is formed along the inner circumferential surface of the case at a position continuous with respect to the discharge passage in the radial direction inward, The system comprises a weir member that changes the direction of the flushing fluid flowing circumferentially through the annular passage to the radially outward direction, thereby allowing the flushing fluid to flow along the discharge passage. The annular road is provided with a groove that is cut out toward the outward direction in the axial direction. The aforementioned weir member is, A fluid receiving section that receives the flushing fluid flowing through the annular passage, It comprises a wide portion that is continuous with the fluid receiving portion and is formed to be wider than the fluid receiving portion, The wide portion is configured to be able to engage with the groove, and is part of a shaft sealing device.

2. The wide portion has a longitudinally extended portion and a shorter longitudinally extended portion, The dimensions of the longitudinal extension are greater than the axial dimension of the portion of the annular road without the groove, and smaller than the axial dimension of the groove in the annular road. The shaft sealing device according to claim 1, wherein the dimension of the short-side extension is smaller than the axial dimension of the portion of the annular road that does not have a groove.

3. The mounting positions for the weir members are set at positions adjacent to the discharge passage on each of the circumferential sides in the annular passage, The shaft sealing device according to claim 1, wherein grooves are provided at each mounting position.

4. The shaft sealing device according to claim 3, wherein the mounting position is provided with circumferential fixing means for fixing the weir member in the circumferential direction.

5. The shaft sealing device according to any one of claims 1 to 4, wherein the radially outer end face of the weir member is a curved surface that conforms to the shape of the annular road.

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