Mechanical seal and method for assembling the mechanical seal

Abstract

We provide mechanical seals that enable highly accurate and uniform assembly. [Solution] The target annular body T comprises a semi-circular first segment 10 and a second segment 20. At each of the two connecting positions C, a circumferential fastener 3 is provided to fasten the first segment 10 and the second segment 20 in the circumferential direction Z. Bolt insertion holes (11, 21) for attaching a flutter 4 that aligns the axial end faces of the first segment 10 and the second segment 20 in the axial direction are formed opening on the axial end faces of the first segment 10 and the second segment 20 and along the axial direction. The bolt insertion holes (11, 21) formed in the first segment 10 and the second segment 20 are located radially outward Y2 from the circumferential fastener 3.

Description

Technical Field

[0001] The present invention relates to a mechanical seal including a stationary ring and a rotating ring arranged along an axial direction in which a rotating shaft extends, and a method for assembling the mechanical seal.

Background Art

[0002] A mechanical seal is used as a shaft seal device for rotating equipment such as pumps and agitators, and suppresses fluid leakage by seal surfaces where a stationary ring and a rotating ring arranged in the axial direction slide relative to each other. Since the seal surface is responsible for the function of suppressing fluid leakage, it is required to have high flatness.

[0003] For example, Japanese Patent Application Laid-Open No. 2011-163561 (Patent Document 1) discloses a split-type rotating ring (16) including a first split body (30) and a second split body (31) divided in the circumferential direction. According to this, an annular rotating ring (16) can be attached to a rotating shaft (11) by connecting the first split body (30) and the second split body (31) so as to entangle the rotating shaft (11). Therefore, there is an advantage that workability is improved.

[0004] Since the rotating ring (16) of Patent Document 1 is configured using the first split body (30) and the second split body (31), the axial end faces of the first split body (30) and the second split body (31) are integrated to form one seal surface. Therefore, in order to increase the flatness of the seal surface, high accuracy is required for adjusting the axial positions of the first split body (30) and the second split body (31). In the technique disclosed in Patent Document 1, the axial positions of the first split body (30) and the second split body (31) are adjusted by a taper pin (44) inserted in the circumferential direction across the first split body (30) and the second split body (31).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] However, adjusting the axial position of both halves (30, 31) using the tapered pin (44) requires fine adjustment of the insertion pressure of the tapered pin (44). Therefore, the adjustment of the axial position of both halves (30, 31) was dependent on the skill level of the operator and could not be said to be highly uniform.

[0007] In light of the above situation, there is a need for a mechanical seal that enables highly accurate and uniform assembly. [Means for solving the problem]

[0008] A mechanical seal comprising a stationary ring and a rotating ring aligned along the axial direction in which the rotating shaft extends, The stationary ring comprises a stationary side sealing surface adjacent to the rotating ring in the axial direction, The rotating ring comprises the fixed-side sealing surface of the stationary ring and the rotating-side sealing surface adjacent in the axial direction, The fixed ring and the rotating ring are used as the target annular body, The aforementioned annular body comprises a semi-circular first segment and a second segment, The first divided piece and the second divided piece are connected at two symmetrical connection points in the circumferential direction, and together they form a ring. At each of the two aforementioned connection positions, A circumferential fastener is provided, which is formed in a columnar shape that penetrates the dividing surface and fastens the first dividing piece and the second dividing piece in the circumferential direction. Bolt insertion holes for attaching flutters that align the axial end faces of the first and second divided pieces in the axial direction are formed to open on the axial end faces of the first and second divided pieces and to be aligned along the axial direction. The bolt insertion holes formed in the first and second segments are positioned radially outward from the circumferential fasteners.

[0009] With this configuration, the radial position of the first and second segmented pieces can be adjusted using circumferential fasteners, and their axial position can be adjusted with high precision using flutter. Furthermore, on the radially outer side relative to the circumferential fasteners, it is easier to secure space near the segmented surface compared to the radially inner side. Therefore, on the radially outer side relative to the circumferential fasteners, it is easier to shorten the circumferential spacing between the two bolt insertion holes for attaching the flutter. Thus, in this configuration, these two bolt insertion holes can be positioned closer together in the circumferential direction, making it easier to minimize the deflection of the flutter when it is pressed by the bolts inserted into these bolt insertion holes. This makes it easier to improve the precision of the axial position of the first and second segmented pieces. As described above, this configuration enables highly accurate and uniform assembly.

[0010] Further features and advantages of the technology relating to this disclosure will become clearer from the following description of exemplary and non-limiting embodiments, with reference to the drawings. [Brief explanation of the drawing]

[0011] [Figure 1] Cross-section of a mechanical seal [Figure 2] Axial view of the rotating ring [Figure 3] View of arrow III in Figure 2 [Figure 4] Enlarged view of the connection point [Figure 5] View from arrow V in Figure 4 [Figure 6] A flowchart showing part of the mechanical seal assembly process. [Modes for carrying out the invention]

[0012] A mechanical seal is used as a shaft sealing device for rotating equipment such as pumps and agitators, and suppresses fluid leakage around the rotating shaft. Hereinafter, embodiments of the mechanical seal will be described with reference to the drawings.

[0013] As shown in FIG. 1, the mechanical seal 100 is installed around the rotating shaft 8 penetrating the equipment case 9.

[0014] In this specification, based on the axis Ax of the rotating shaft 8, the "axial direction X", the "radial direction Y", and the "circumferential direction Z" are defined. Also, one side in the axial direction X is defined as the "first axial side X1", and the other side is defined as the "second axial side X2". The inner side in the radial direction Y is defined as the "inner radial side Y1", and the outer side is defined as the "outer radial side Y2". <OO00084> The mechanical seal 100 includes a stationary ring F, a rotating ring R, and a stopper ring S arranged along the axial direction X in which the rotating shaft 8 extends. The stationary ring F is fixed to the equipment case 9. The rotating ring R and the stopper ring S are fixed to the rotating shaft 8 and rotate integrally with the rotating shaft 8. The stationary ring F, the rotating ring R, and the stopper ring S are arranged in order from the first axial side X1 toward the second axial side X2.

[0016] The stationary ring F is a seal ring and is configured to be operable in the axial direction X by being urged by the spring 6. The rotating ring R is a mating ring whose position in the axial direction X is fixed.

[0017] A spring retainer 7 is provided in the central hole of the equipment case 9 via an O-ring 99. The spring retainer 7 includes a retainer body 70 that holds the spring 6, and a pressing body 71 that presses the stationary ring F from the outer radial side Y2 toward the inner radial side Y1.

[0018] The fixed ring F is an annular body provided around the rotation axis 8. The fixed ring F is adjacent to the retainer body 70 on the second axial side X2 and adjacent to the pressing body 71 on the radially inner side Y1. An O-ring 98 is interposed between the fixed ring F and the retainer body 70 in the axial direction X, and the space between the fixed ring F and the retainer body 70 is sealed.

[0019] The fixed ring F has a fixed-side seal surface Fs that is adjacent to the rotating ring R in the axial direction X. The fixed-side seal surface Fs is the axial end surface Xs of the fixed ring F. In the present embodiment, it is the axial end surface Xs on the second axial side X2 of the fixed ring F. The fixed-side seal surface Fs is polished, and its surface roughness (arithmetic mean roughness Ra) is preferably 0.2 [μm] or less.

[0020] The rotating ring R is an annular body provided around the rotation axis 8. In the present embodiment, the rotating ring R is adjacent to the fixed ring F on the second axial side X2. The rotating ring R is fixed to the rotation axis 8 via a stopper ring S and is configured to rotate integrally with the rotation axis 8. An O-ring 97 is interposed between the rotating ring R and the rotation axis 8 in the radial direction Y, and the space between the rotating ring R and the rotation axis 8 is sealed.

[0021] The rotating ring R has a rotating-side seal surface Rs that is adjacent to the fixed-side seal surface Fs of the fixed ring F in the axial direction X. The rotating-side seal surface Rs is the axial end surface Xs of the rotating ring R. In the present embodiment, it is the axial end surface Xs on the first axial side X1 of the rotating ring R. The rotating-side seal surface Rs is polished, and its surface roughness (arithmetic mean roughness Ra) is preferably 0.2 [μm] or less.

[0022] The fixed-side seal surface Fs and the rotating-side seal surface Rs slide against each other to form the seal surface of the mechanical seal 100. Thereby, leakage of fluid is suppressed.

[0023] The stopper ring S is an annular body provided around the rotation axis 8. In the present embodiment, the stopper ring S is adjacent to the rotating ring R on the second axial side X2.

[0024] The stopper ring S is fixed to the rotating shaft 8 by a set screw Sa positioned along the radial direction Y, and is configured to rotate integrally with the rotating shaft 8. The stopper ring S is also connected to the rotating ring R by a drive pin Sb positioned along the axial direction X, and is configured to rotate integrally with the rotating ring R. In this way, the rotating ring R is fixed to the rotating shaft 8 via the stopper ring S, and is configured to rotate along with the rotation of the rotating shaft 8.

[0025] At least one of the fixed ring F, rotating ring R, and stopper ring S described above can be constructed using a plurality of segmented pieces that are cut radially in the Y direction and divided circumferentially in the Z direction, and the plurality of segmented pieces are connected in the circumferential Z direction to form an annular shape. These annular bodies can be attached to the rotating shaft 8 by connecting the plurality of segmented pieces in the circumferential Z direction so as to wrap around the rotating shaft 8. In other words, the annular bodies can be attached while the rotating shaft 8 is installed in the rotating equipment. Thus, the segmented structure of these annular bodies contributes to improved workability.

[0026] Here, since the sealing surface of the mechanical seal 100 is responsible for suppressing fluid leakage, high precision is required in the flatness of the fixed-side sealing surface Fs and the rotating-side sealing surface Rs, which slide against each other.

[0027] As described above, when the rotating ring R is a segmented annular body composed of multiple segmented pieces, the axial end faces Xs of each segmented piece form a single rotating side sealing surface Rs. In this case, if the segmented pieces are connected with axial misalignment, a step in the axial direction X will occur on the rotating side sealing surface Rs, affecting the flatness of the rotating side sealing surface Rs. A similar problem arises when the stationary ring F is a segmented annular body. Therefore, high precision is required for the assembly of segmented annular bodies, but conventionally, this has depended on the skill level of the worker performing the assembly.

[0028] Therefore, the assembly method for the mechanical seal 100 according to this disclosure allows for the assembly of the segmented annular body with high precision, regardless of the operator's skill level. Furthermore, the mechanical seal 100 according to this disclosure has a structure that enables such assembly.

[0029] In the following, we define the target annular body T as at least one of the stationary ring F, the rotating ring R, and the stopper ring S, and describe the structure of the target annular body T.

[0030] In this embodiment, both the rotating ring R and the stopper ring S are the target annular body T. The target annular body T is assembled using a flutter 4. The flutter 4 is made of a flat plate-shaped member, and its surface is preferably polished. By arranging the flat plate-shaped flutter 4 across both sides of the dividing surface Ds (see Figure 2, etc.) of the target annular body T and pressing the flutter 4 against the axial end face Xs of the target annular body T from the axial X, the axial end face Xs can be uniformly aligned. As a result, when the target annular body T is a rotating ring R, the flatness of the rotating side sealing surface Rs can be finished with high precision, and the finish is less affected by the skill level of the worker. Therefore, it is easier to ensure uniformity of assembly.

[0031] In the rotating ring R, the flutter 4 is used only during assembly. That is, in the final product, the flutter 4 is removed from the rotating ring R. On the other hand, in the stopper ring S, the flutter 4 remains attached to the stopper ring S even after being used during assembly. Since the flutter 4 may also be used during maintenance of the mechanical seal 100, keeping it attached to the stopper ring S in this way makes management easier. In other words, in this embodiment, the flutter 4 is attached to the stopper ring S.

[0032] Figures 2 to 5 show the rotating ring R during assembly, in which the flutter 4 is attached to the rotating ring R. As described above, after assembly, the flutter 4 is removed from the rotating ring R. Below, the structure of the target annular body T will be explained using the rotating ring R as an example, but its main structure is similar for the stopper ring S.

[0033] As shown in Figures 2 and 3, the target annular body T comprises a semi-circular first segment 10 and a second segment 20. The first segment 10 and the second segment 20 are connected by a dividing surface Ds at two symmetrical connection positions C in the circumferential direction Z, and together they form an annular structure.

[0034] The target annular body T is formed by the connection of two members, a first segment 10 and a second segment 20, in the circumferential direction Z. Therefore, the first segment 10 and the second segment 20 are connected at two points in the circumferential direction Z. The position where they are connected is the connection position C, and the surface where the first segment 10 and the second segment 20 meet at this connection position C is the segmentation surface Ds.

[0035] Furthermore, since each of the first and second division pieces 10 and 20 is formed in a semi-circular shape, that is, in an arc shape with a central angle of 180°, one connection point C is located 180° away in the circumferential direction Z from the other connection point C. Therefore, the two connection points C are positioned symmetrically in the circumferential direction Z. The division planes Ds are located on a virtual straight line L that longitudinally bisects the symmetric annular body T in the radial direction Y, as shown in the axial view X in Figure 2.

[0036] At each of the two connection positions C, a circumferential fastener 3 is provided to fasten the first dividing piece 10 and the second dividing piece 20 in the circumferential direction Z. The circumferential fastener 3 is formed in a columnar shape that penetrates the dividing surface Ds. More specifically, the circumferential fastener 3 is formed in a columnar shape (cylindrical in this example) having a linear central axis. Furthermore, the circumferential fastener 3 is arranged to penetrate the dividing surface Ds along a direction perpendicular to the dividing surface Ds. In this embodiment, the circumferential fastener 3 is a reamer bolt 3. The first dividing piece 10 and the second dividing piece 20 are fastened together by the reamer bolt 3 to form a single symmetric annular body T.

[0037] The reamer bolt 3 has a function to connect the first segment 10 and the second segment 20, as well as a function to adjust the radial position of the first segment 10 and the second segment 20. In this embodiment, the outer surface of the reamer bolt 3 is formed parallel to the axis. By using such a reamer bolt 3, workability is improved compared to when using a tapered pin that requires adjustment of insertion pressure.

[0038] In this embodiment, a receiving recess 12 for accommodating the head 3a of the reamer bolt 3 is formed at each of the two connection positions C. The shaft portion 3b of the reamer bolt 3 penetrates the first dividing piece 10 and the second dividing piece 20. The two receiving recesses 12 at each connection position C are formed on the same side with respect to the dividing surface Ds in an axial view X. This configuration allows the reamer bolt 3 to be attached to the rotating ring R from the same side with respect to the dividing surface Ds, thus improving work efficiency. In the illustrated example, the two receiving recesses 12 are formed in the first dividing piece 10.

[0039] In this embodiment, the recess 22 into which the tip of the shaft portion 3b of the reamer bolt 3 protrudes is formed on the opposite side from the receiving recess 12 with respect to the dividing surface Ds. That is, the two recesses 22 at each connection position C are formed on the same side with respect to the dividing surface Ds in an axial view X. The tip of the shaft portion 3b of the reamer bolt 3 is fastened with a nut in the recess 22. With this configuration, the nuts on the two reamer bolts 3 can be fastened from the same side with respect to the dividing surface Ds, which improves work efficiency. In the illustrated example, the two recesses 22 are formed in the second dividing piece 20.

[0040] At each of the two connection positions C, bolt insertion holes (11, 21) for attaching a flutter 4 that aligns the axial end faces Xs of the first and second divided pieces 10 and 20 with the axial direction X are formed along the axial direction X, opening into the axial end faces Xs of the first and second divided pieces 10 and 20 respectively. With the flutter 4 in contact with the axial end faces Xs, the flutter 4 is attached to the axial end faces Xs by inserting bolts 40 into the bolt insertion holes (11, 21).

[0041] When the target annular body T is a rotating ring R, the bolt insertion holes (11, 21) are formed to open to the axial end face Xs of the rotating ring R that is opposite to the rotating side sealing surface Rs (see Figure 3). In this embodiment, the bolt insertion holes (11, 21) are formed to open to the axial end face Xs of the axial second side X2 of the rotating ring R.

[0042] At each of the two connection positions C, the bolt insertion holes (11, 21) formed in the first segment 10 and the second segment 20 are positioned radially outward Y2 from the reamer bolt 3.

[0043] As shown in Figure 4, it is easier to secure space near the dividing surface Ds at the radially outer Y2 relative to the reamer bolt 3 compared to the radially inner Y1, making it easier to position the two bolt insertion holes (11, 21) closer to the dividing surface Ds. In other words, because the reamer bolt 3 is formed in a columnar shape that penetrates the dividing surface Ds, the outer circumferential surface Ys2 of the target annular body T becomes further radially Y from the reamer bolt 3 the closer it is to the dividing surface Ds. On the other hand, the inner circumferential surface Ys1 of the target annular body T becomes closer to the reamer bolt 3 the closer it is to the dividing surface Ds. Therefore, it is easier to secure a wide space in the radially Y direction near the dividing surface Ds at the radially outer Y2 relative to the reamer bolt 3, while it is more difficult to secure space in the radially Y direction near the dividing surface Ds at the radially inner Y1 relative to the reamer bolt 3.

[0044] If we were to secure space to form two bolt insertion holes (11, 12) radially inward Y1 from the reamer bolt 3, we would need to increase the distance between the two bolt insertion holes (11, 12) in the circumferential Z direction. For example, in the example in Figure 4, if we were to secure space to form two bolt insertion holes (11, 12) radially inward Y1 from the reamer bolt 3, we would need to space the two bolt insertion holes (11, 12) in the circumferential Z direction by about the same amount as the dimensions of the reamer bolt 3. In this case, the flutter 4 would become larger, and the flutter 4 would be more prone to deflection because the pressing positions of the two bolts 40 would be separated in the circumferential Z direction.

[0045] However, as described above, in this embodiment, the two bolt insertion holes (11, 21) at the connection position C are positioned radially outward Y2 from the reamer bolt 3. Therefore, the two bolt insertion holes (11, 21) can be brought closer to the circumferential direction Z, and the flutter 4 can be made smaller. As a result, the deflection of the flutter 4 can be suppressed, and the axial end face Xs of the target annular body T can be appropriately pressed.

[0046] In this embodiment, the flutter 4 and the reamer bolt 3 partially overlap in an axial view X. This allows the size of the pressing surface of the flutter 4 to be appropriately secured while positioning the two bolt insertion holes (11, 21) at the connection position C radially outward Y2 from the reamer bolt 3.

[0047] Figure 5 is a view along arrow V in Figure 4, and is a radial Y view of the dividing surface Ds viewed from the radially outer side Y2. As shown in Figure 5, in this embodiment, at the connection position C, the bolt insertion holes (11, 21) formed in the first dividing piece 10 and the second dividing piece 20 are arranged to overlap with the reamer bolt 3 in the radial Y view. This allows the two bolt insertion holes (11, 21) and the reamer bolt 3 at the connection position C to be arranged in a consolidated manner. Therefore, it is easier to miniaturize the target annular body T.

[0048] Thus, at the two connection points C where the first segment 10 and the second segment 20 are connected, the two bolt insertion holes (11, 21) for attaching the flutter 4 are positioned radially outward Y2 from the reamer bolts 3. The bolts 40 inserted into each bolt insertion hole (11, 21) are positioned radially outward Y2 from the center of the flutter 4. Therefore, the pressing position by the bolts 40 is biased radially outward Y2 from the center of the radial direction Y in the flutter 4.

[0049] However, as shown in Figure 2, the mounting structure of the flutter 4 at one connection position C and the mounting structure of the flutter 4 at the other connection position C are point-symmetric with respect to the axis Ax. Therefore, even if the pressing position of the flutter 4 by the bolt 40 is biased radially outward Y2, the bias cancels out between the one connection position C and the other connection position C, making it possible to appropriately press the target annular body T in the axial direction X.

[0050] Next, we will explain the assembly method of the mechanical seal 100, and more specifically, the assembly method of the target annular body T.

[0051] As shown in Figure 6, this assembly method comprises a connecting step S1 for connecting the first divided piece 10 and the second divided piece 20, an axial adjustment step S2 for aligning the first divided piece 10 and the second divided piece 20 in the axial direction X, and a radial adjustment step S3 for aligning the first divided piece 10 and the second divided piece 20 in the radial direction Y.

[0052] In the connecting process S1, a reamer bolt 3 is inserted across the first segment 10 and the second segment 20, and the reamer bolt 3 is temporarily tightened. "Temporary tightening" means tightening with some allowance for tightening. In the connecting process S1, the reamer bolt 3 is temporarily tightened in such a way that relative movement of the first segment 10 and the second segment 20 in the axial direction X is permitted.

[0053] Following the coupling process S1, an axial adjustment process S2 is performed. In the axial adjustment process S2, the flutter 4 is brought into contact with the respective axial end faces Xs of the first segment 10 and the second segment 20 from the axial direction X, and the flutter 4 is tightened against the respective axial end faces Xs by bolts 40 inserted into bolt insertion holes (11, 21). The respective axial end faces Xs of the first segment 10 and the second segment 20, located on both sides in the circumferential direction Z with respect to the segment surface Ds, are pressed by a single flutter 4. As a result, the respective axial end faces Xs of the first segment 10 and the second segment 20 become flush with each other, along the surface of the flutter 4.

[0054] Thus, by using the flutter 4 in the axial adjustment step S2, the first segment 10 and the second segment 20 can be aligned with high precision in the axial direction X. Furthermore, in the aforementioned connecting step S1, the temporary tightening of the reamer bolt 3 provides a margin of error that allows the first segment 10 and the second segment 20 to move relative to each other in the axial direction X, thereby further improving the accuracy of the axial position adjustment in the subsequent axial adjustment step S2.

[0055] Following the axial adjustment process S2, the radial adjustment process S3 is performed. In the radial adjustment process S3, the first segment 10 and the second segment 20 are aligned in the radial direction Y, and then the reamer bolt 3 used in the connecting process S1 is tightened to fasten the first segment 10 and the second segment 20 together. "Final tightening" means tightening so that there is no excess tightening allowance. As described above, the axial adjustment process S2 is performed before the radial adjustment process S3, and the axial position of the first segment 10 and the second segment 20 has already been adjusted, so in this radial adjustment process S3, only the radial position of the first segment 10 and the second segment 20 is adjusted. In other words, the axial position of the first segment 10 and the second segment 20, which requires higher precision than the radial position, is less affected by the radial adjustment process S3.

[0056] According to the mechanical seal 100 and its assembly method described above, high-precision and highly uniform assembly is possible.

[0057] [Other Embodiments] Next, other embodiments will be described.

[0058] (1) In the above embodiment, an example was described in which the circumferential fastener 3 is a reamer bolt 3 whose outer surface is parallel to the axis. However, the example is not limited to this example, and tapered pins or bolts may also be used as the circumferential fastener 3.

[0059] (2) In the above embodiment, an example was described in which the bolt insertion holes (11, 21) formed in the first divided piece 10 and the second divided piece 20 are arranged to overlap with the reamer bolt 3 in a radial Y view. However, the invention is not limited to this example, and the two bolt insertion holes (11, 21) may be arranged so as not to overlap with the reamer bolt 3 in a radial Y view.

[0060] (3) In the above embodiment, an example was described in which both the rotating ring R and the stopper ring S are the target annular body T. However, the embodiment is not limited to such an example, and it is sufficient if at least one of the stationary ring F, the rotating ring R, and the stopper ring S is the target annular body T.

[0061] (4) In the above embodiment, an example was described in which the two receiving recesses 12 for accommodating the head 3a of the reamer bolt 3 are formed on the same side with respect to the dividing surface Ds in an axial view X. However, the example is not limited to this example, and the two receiving recesses 12 may be formed on opposite sides with respect to the dividing surface Ds.

[0062] (5) In the above embodiment, an example was described in which the rotating ring R is fixed to the rotating shaft 8 using a stopper ring S. However, the invention is not limited to such an example, and the rotating ring R may be fixed to the rotating shaft 8 without using a stopper ring S. For example, the rotating ring R may be fixed to the rotating shaft 8 using a flat plate-shaped key that engages with grooves extending in the axial direction X provided on both the inner surface of the rotating ring R and the outer surface of the rotating shaft 8.

[0063] (6) The mechanical seal 100 relating to this disclosure can be applied to balanced, unbalanced, rotary, and stationary mechanical seals.

[0064] (7) The configurations disclosed in the embodiments described above can be applied in combination with configurations disclosed in other embodiments, as long as they do not cause any inconsistencies. 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.

[0065] [Summary of this embodiment] The following is a summary of this embodiment.

[0066] A mechanical seal comprising a stationary ring and a rotating ring aligned along the axial direction in which the rotating shaft extends, The stationary ring comprises a stationary side sealing surface adjacent to the rotating ring in the axial direction, The rotating ring comprises the fixed-side sealing surface of the stationary ring and the rotating-side sealing surface adjacent in the axial direction, The fixed ring and the rotating ring are used as the target annular body, The aforementioned annular body comprises a semi-circular first segment and a second segment, The first divided piece and the second divided piece are connected at two symmetrical connection points in the circumferential direction, and together they form a ring. At each of the two aforementioned connection positions, A circumferential fastener is provided, which is formed in a columnar shape that penetrates the dividing surface and fastens the first dividing piece and the second dividing piece in the circumferential direction. Bolt insertion holes for attaching flutters that align the axial end faces of the first and second divided pieces in the axial direction are formed to open on the axial end faces of the first and second divided pieces and to be aligned along the axial direction. The bolt insertion holes formed in the first and second segments are positioned radially outward from the circumferential fasteners.

[0067] With this configuration, the radial position of the first and second segmented pieces can be adjusted using circumferential fasteners, and their axial position can be adjusted with high precision using flutter. Furthermore, on the radially outer side relative to the circumferential fasteners, it is easier to secure space near the segmented surface compared to the radially inner side. Therefore, on the radially outer side relative to the circumferential fasteners, it is easier to shorten the circumferential spacing between the two bolt insertion holes for attaching the flutter. Thus, in this configuration, these two bolt insertion holes can be positioned closer together in the circumferential direction, making it easier to minimize the deflection of the flutter when it is pressed by the bolts inserted into these bolt insertion holes. This makes it easier to improve the precision of the axial position of the first and second segmented pieces. As described above, this configuration enables highly accurate and uniform assembly.

[0068] The circumferential fastener is a reamer bolt, At each of the two aforementioned connection positions, Preferably, the bolt insertion holes formed in the first and second divided pieces are arranged to overlap with the circumferential fasteners in a radial view along the radial direction.

[0069] This configuration allows the two bolt insertion holes at the connection point and the circumferential fastener to be arranged in a consolidated manner, making it easier to miniaturize the mechanical seal.

[0070] The rotating ring is connected to the aforementioned rotating ring and includes a stopper ring fixed to the aforementioned rotating shaft, It is preferable that both the rotating ring and the stopper ring are the target annular body.

[0071] With this configuration, flutter can be used in the assembly of the rotating ring and the stopper ring connected to it. Therefore, it becomes possible to properly assemble the rotating ring and the stopper ring with respect to the rotating shaft.

[0072] The rotating ring is the target annular body, The circumferential fastener is a reamer bolt, Each of the two aforementioned connection positions has a recess for accommodating the head of the reamer bolt. Preferably, the two receiving recesses are formed on the same side with respect to the dividing surface in an axial view along the axial direction.

[0073] With this configuration, the reamer bolt can be attached to the rotating ring from the same side relative to the dividing surface, making it easier to improve work efficiency.

[0074] The above describes the method for assembling the mechanical seal, A connecting step of connecting the first divided piece and the second divided piece, After the connecting step, an axial adjustment step is performed to align the first divided piece and the second divided piece in the axial direction, The axial adjustment step is followed by a radial adjustment step of aligning the first divided piece and the second divided piece in the radial direction. In the connecting step, the circumferential fastener is inserted across the first and second divided pieces, and the circumferential fastener is temporarily tightened. In the axial adjustment step, the flutter is brought into contact with the axial end faces of the first and second divided pieces from the axial direction, and the flutter is tightened against the axial end faces of the first and second divided pieces with bolts inserted into the bolt insertion holes. In the radial adjustment step, it is preferable to align the first and second divided pieces radially, and then tighten the circumferential fastener used in the connecting step to tighten the first and second divided pieces together.

[0075] This assembly method allows for high-precision adjustment of the axial position between the first and second segmented pieces using a flutter. Furthermore, the axial adjustment process using the flutter is performed before the radial adjustment process in which the circumferential fasteners are fully tightened. Therefore, the axial adjustment process, which contributes to improving the flatness of the sealing surface, can be performed with high work efficiency, making it easier to improve the flatness of the sealing surface after assembly. [Industrial applicability]

[0076] The technology relating to this disclosure can be used in a mechanical seal comprising a stationary ring and a rotating ring arranged along the axial direction in which the rotating shaft extends, and in a method for assembling said mechanical seal. [Explanation of symbols]

[0077] 100: Mechanical seal 8: Rotation axis F: Fixed ring Fs: Fixed side sealing surface R: Rotating ring Rs: Rotating side sealing surface S: Stopper Ring 4: Flutter 3: Reamer bolt (circumferential fastener) 3a:Head 10: 1st divided piece 12: Recessed area 20:Second divided piece 22: Recess 40: Bolt C: Connection position Ds: Division plane T: Target ring body X: Axial direction Xs: Axial end face Y: Radial direction Z: Circumferential direction S1: Connection process S2: Axial adjustment process S3: Radial adjustment process

Claims

1. A mechanical seal comprising a stationary ring and a rotating ring aligned along the axial direction in which the rotating shaft extends, The stationary ring comprises a stationary side sealing surface adjacent to the rotating ring in the axial direction, The rotating ring comprises the fixed-side sealing surface of the stationary ring and the rotating-side sealing surface adjacent in the axial direction, The fixed ring and the rotating ring are used as the target annular body, The aforementioned annular body comprises a semi-circular first segment and a second segment, The first divided piece and the second divided piece are connected at two symmetrical connection points in the circumferential direction, and together they form an annular structure. At each of the two aforementioned connection positions, A circumferential fastener is provided, which is formed in a columnar shape that penetrates the dividing surface and fastens the first dividing piece and the second dividing piece in the circumferential direction. Bolt insertion holes for attaching flutters that align the axial end faces of the first and second divided pieces in the axial direction are formed to open on the axial end faces of the first and second divided pieces and to be aligned along the axial direction. A mechanical seal in which the bolt insertion holes formed in the first and second segmented pieces are located radially outward from the circumferential fastener.

2. The circumferential fastener is a reamer bolt, At each of the two aforementioned connection positions, The mechanical seal according to claim 1, wherein the bolt insertion holes formed in each of the first and second divided pieces are arranged to overlap with the circumferential fasteners in a radial view along the radial direction.

3. The rotating ring is connected to the aforementioned rotating ring and includes a stopper ring fixed to the aforementioned rotating shaft, The mechanical seal according to claim 1, wherein both the rotating ring and the stopper ring are the target annular body.

4. The rotating ring is the target annular body, The circumferential fastener is a reamer bolt, Each of the two aforementioned connection positions has a recess for accommodating the head of the reamer bolt. The mechanical seal according to claim 1, wherein the two receiving recesses are formed on the same side with respect to the dividing surface in an axial view along the axial direction.

5. A method for assembling a mechanical seal according to any one of claims 1 to 4, A connecting step of connecting the first divided piece and the second divided piece, After the connecting step, an axial adjustment step is performed to align the first divided piece and the second divided piece in the axial direction, The process includes, after the axial adjustment step, a radial adjustment step in which the first divided piece and the second divided piece are aligned in the radial direction. In the connecting step, the circumferential fastener is inserted across the first and second divided pieces, and the circumferential fastener is temporarily tightened. In the axial adjustment step, the flutter is brought into contact with the axial end faces of the first and second divided pieces from the axial direction, and the flutter is tightened against the axial end faces of the first and second divided pieces with bolts inserted into the bolt insertion holes. A method for assembling a mechanical seal, wherein in the radial adjustment step, the first segment and the second segment are aligned in the radial direction, and then the circumferential fastener used in the connecting step is tightened to fasten the first segment and the second segment together.

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