JP7064071B2 - Shaft sealing device and rotary machine equipped with this shaft sealing device - Google Patents

Description

The present disclosure relates to a shaft sealing device and a rotary machine including the shaft sealing device.

Patent Document 1 describes a shaft sealing device that seals between a fluid high pressure side and a fluid low pressure side in the axial direction of a rotating shaft in a rotating machine such as a gas turbine, a steam turbine, or a compressor. As shown in FIG. 12, such a shaft seal device 100 includes an annular seal piece laminate 102 in which a plurality of thin plate seal pieces 101 are laminated in the circumferential direction of the rotating shaft 110, a fluid high pressure side 108, and a fluid. The high-pressure side retainer 103 and the low-pressure side retainer 104 that support the seal piece laminate 102 in the housing 107 by sandwiching the outer peripheral edge side of the seal piece laminate 102 from each of the low-pressure side 109, and the fluid high-pressure side of the seal piece laminate 102. It includes a side leaf 105 provided so as to be in contact with the side surface 102a of the 108, and a back leaf 106 provided so as to be in contact with the side surface 102b of the fluid low pressure side 109 of the seal piece laminate 102.

In the shaft sealing device 100 having such a configuration, when the rotating shaft 110 is not rotating, each thin plate seal piece 101 comes into contact with the rotating shaft 110 under a predetermined pressure, but when the rotating shaft 110 is rotated, a dynamic pressure effect is obtained. A levitation force acts on each thin plate seal piece 101 to form a minute gap between each thin plate seal piece 101 and the rotating shaft 110 to seal the fluid. Since the thin plate seal piece 101 and the rotary shaft 110 do not come into contact with each other when the rotary shaft 110 is rotated, wear of each thin plate seal piece 101 and the rotary shaft 110 can be suppressed.

Japanese Unexamined Patent Publication No. 2011-185219

However, in the conventional shaft sealing device shown in FIG. 12, since the side leaf 105 is in contact with the side surface 102a of the fluid high pressure side 108 of the seal piece laminate 102, wear of the side leaf 105 has become a problem. A shaft sealing device having a configuration without a side leaf 105 (side leafless structure) has also been developed, but as shown in FIG. 13, in the shaft sealing device 200 having a side leafless structure, the housing 107 and the seal piece are laminated. When the fluid 201 flowing into the body 102 with the side surface 102a of the fluid high pressure side 108 flows between the adjacent thin plate seal pieces 101, a flow (downflow 202) toward the rotating shaft 110 is generated and the thin plate seal piece 101 is squeezed. Since it is pressed against the rotating shaft 110, there is a problem that the thin plate seal piece 101 is likely to be worn.

In view of the above circumstances, at least one embodiment of the present disclosure is an object of providing a shaft sealing device capable of suppressing wear of a thin plate sealing piece and a rotating machine provided with the shaft sealing device.

The shaft sealing device according to at least one embodiment of the present invention is
A shaft sealing device that seals between the fluid high pressure side and the fluid low pressure side in the axial direction of the rotating shaft.
A seal piece laminate including a plurality of thin plate seal pieces laminated in the circumferential direction of the rotation axis, and
A high-pressure side retainer and a low-pressure side retainer that support the seal piece laminate by sandwiching the outer peripheral edge side of the seal piece laminate from each of the fluid high-pressure side and the fluid low-pressure side.
A plate-shaped covering member that is supported by the high-pressure side retainer and extends from the high-pressure side retainer toward the inner peripheral edge side of the seal piece laminate, and is a side surface of the seal piece laminate on the fluid high-pressure side. A covering member that forms a continuous gap over the entire circumference of the rotating shaft ,
It is configured separately from the low-pressure side retainer, is fixed by being sandwiched between the low-pressure side retainer and the seal piece laminate, and extends from the low-pressure side retainer toward the inner peripheral edge side of the seal piece laminate. A plate-shaped back leaf with a back leaf configured to be in contact with the side surface of the seal piece laminate on the low pressure side of the fluid.
Equipped with
When the distance between the inner peripheral edge of the covering member and the axis of the rotating shaft is defined as D1, and the distance between the inner peripheral edge of the back leaf and the axial center of the rotating shaft is defined as D2, the relationship D1> D2 is satisfied. ..

According to the above configuration , a continuous gap is formed between the covering member and the side surface of the seal piece laminate on the high pressure side over the entire circumference of the rotating shaft, so that wear between the covering member and the thin plate seal piece is avoided. be able to. In addition, since it is difficult for fluid to flow into the gap between the covering member and the side surface of the seal piece laminate on the high pressure side, the occurrence of fluid downflow between adjacent thin plate seal pieces is reduced, and the thin plate is rotated when the rotating shaft is rotated. It is possible to prevent the seal piece from coming into contact with the rotating shaft. As a result, wear of the thin plate seal piece can be suppressed.

The shaft sealing device according to at least one embodiment of the present invention is
A shaft sealing device that seals between the fluid high pressure side and the fluid low pressure side in the axial direction of the rotating shaft.
A seal piece laminate including a plurality of thin plate seal pieces laminated in the circumferential direction of the rotation axis, and
A high-pressure side retainer and a low-pressure side retainer that support the seal piece laminate by sandwiching the outer peripheral edge side of the seal piece laminate from each of the fluid high-pressure side and the fluid low-pressure side.
A plate-shaped covering member that is supported by the high-pressure side retainer and extends from the high-pressure side retainer toward the inner peripheral edge side of the seal piece laminate, and is a side surface of the seal piece laminate on the fluid high-pressure side. A covering member that forms a continuous gap over the entire circumference of the rotating shaft,
A housing for accommodating the seal piece laminate, the high-pressure side retainer, the low-pressure side retainer, and the covering member.
Equipped with
The covering member is integrally configured with the high-pressure side retainer, and the inner peripheral edge of the covering member is configured to abut on the support surface of the housing.

According to the above configuration , since the inner peripheral edge of the covering member is in contact with the support surface of the housing, the fluctuation of the covering member in the axial direction of the rotating shaft is suppressed, and the fluid high pressure side of the covering member and the seal piece laminate is suppressed. It is possible to suppress fluctuations in the width of the gap defined between the side surface and the side surface. As a result, it is possible to reduce the possibility that the covering member comes into contact with the side surface of the seal piece laminate on the fluid high pressure side.

The shaft sealing device according to at least one embodiment of the present invention is
A shaft sealing device that seals between the fluid high pressure side and the fluid low pressure side in the axial direction of the rotating shaft.
A seal piece laminate including a plurality of thin plate seal pieces laminated in the circumferential direction of the rotation axis, and
A high-pressure side retainer and a low-pressure side retainer that support the seal piece laminate by sandwiching the outer peripheral edge side of the seal piece laminate from each of the fluid high-pressure side and the fluid low-pressure side.
A plate-shaped covering member that is supported by the high-pressure side retainer and extends from the high-pressure side retainer toward the inner peripheral edge side of the seal piece laminate, and is a side surface of the seal piece laminate on the fluid high-pressure side. A covering member that forms a continuous gap over the entire circumference of the rotating shaft,
A housing for accommodating the seal piece laminate, the high-pressure side retainer, the low-pressure side retainer, and the covering member.
Equipped with
The covering member is integrally configured with the high pressure side retainer.
The high pressure side retainer is configured to abut on the support surface of the housing.

According to the above configuration , since the high-pressure side retainer is in contact with the support surface of the housing, it is not necessary to bring the covering member into contact with the housing. If the covering member does not abut on the housing, the covering member can be made variable so as to approach the fluid high pressure side side of the seal piece laminate, thereby the axial pressure difference and fluid of the axis of rotation. It can be adjusted so that the gap between the covering member and the side surface of the seal piece laminate on the fluid high pressure side becomes smaller according to the temperature and the like.

The shaft sealing device according to at least one embodiment of the present invention is
A shaft sealing device that seals between the fluid high pressure side and the fluid low pressure side in the axial direction of the rotating shaft.
A seal piece laminate including a plurality of thin plate seal pieces laminated in the circumferential direction of the rotation axis, and
A high-pressure side retainer and a low-pressure side retainer that support the seal piece laminate by sandwiching the outer peripheral edge side of the seal piece laminate from each of the fluid high-pressure side and the fluid low-pressure side.
A plate-shaped covering member that is supported by the high-pressure side retainer and extends from the high-pressure side retainer toward the inner peripheral edge side of the seal piece laminate, and is a side surface of the seal piece laminate on the fluid high-pressure side. A covering member that forms a continuous gap over the entire circumference of the rotating shaft,
A housing for accommodating the seal piece laminate, the high-pressure side retainer, the low-pressure side retainer, and the covering member.
Equipped with
The covering member is configured separately from the high-pressure side retainer.
The high pressure side retainer is configured to abut on the support surface of the housing.
The covering member is configured to approach the side surface of the seal piece laminate toward the fluid high pressure side by the pressure difference in the axial direction.
An engaging space is formed in the high-pressure side retainer, the covering member has an engaging portion that can be inserted into the engaging space, and the engaging portion is inserted into the engaging space. Then, the covering member is attached to the high pressure side retainer, and the cover member is attached.
With the engaging portion inserted in the engaging space, there is a gap in the axial direction of the rotating shaft between the inner surface in the engaging space and the engaging portion.

According to the above configuration , the covering member can move in the axial direction of the rotating shaft according to the pressure difference in the axial direction of the rotating shaft, so that the covering member and the side surface of the seal piece laminate on the fluid high pressure side can be moved. It can be adjusted so that the gap becomes smaller.

According to at least one embodiment of the present disclosure, a continuous gap is formed between the covering member and the side surface of the seal piece laminate on the high pressure side over the entire circumference of the rotation axis, so that the covering member and the thin plate seal piece are formed. Wear with and can be avoided. In addition, since it is difficult for fluid to flow into the gap between the covering member and the side surface on the high pressure side of the seal piece laminate, the occurrence of fluid downflow between adjacent thin plate seal pieces is reduced, and the thin plate is rotated when the rotating shaft is rotated. It is possible to prevent the seal piece from coming into contact with the rotating shaft. As a result, wear of the thin plate seal piece can be suppressed.

It is a figure which shows the structure of the shaft sealing apparatus which concerns on Embodiment 1 of this disclosure. It is a side view of the shaft sealing apparatus which concerns on Embodiment 1 of this disclosure. It is a front view of the thin plate seal piece of the shaft seal apparatus which concerns on Embodiment 1 of this disclosure. It is an exploded view of the shaft sealing apparatus which concerns on Embodiment 1 of this disclosure. It is a partially enlarged view of the seal piece laminated body of the shaft seal apparatus which concerns on Embodiment 1 of this disclosure as seen from the direction facing the inner peripheral edge thereof. It is a figure which shows the structure of the modification of the shaft sealing apparatus which concerns on Embodiment 1 of this disclosure. It is a figure which shows the structure of the shaft sealing apparatus which concerns on Embodiment 2 of this disclosure. It is a figure which shows the structure of the modification of the shaft sealing apparatus which concerns on Embodiment 2 of this disclosure. It is a figure which shows the structure of another modification of the shaft sealing apparatus which concerns on Embodiment 2 of this disclosure. It is a figure which shows the structure of the high pressure side retainer and the covering member of the shaft sealing apparatus which concerns on Embodiment 3 of this disclosure. It is a figure which shows the structure of the modification of the high pressure side retainer and the covering member of the shaft sealing apparatus which concerns on Embodiment 3 of this disclosure. It is a figure which shows the structure of the conventional shaft seal apparatus. It is a figure which shows the structure of another conventional shaft seal device.

Hereinafter, some embodiments of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the following embodiments. The dimensions, materials, shapes, relative arrangements, and the like of the components described in the following embodiments are not intended to limit the scope of the present invention to that, but are merely explanatory examples.

(Embodiment 1)
As shown in FIG. 1, the shaft sealing device 1 according to the first embodiment of the present disclosure is a rotating machine such as a gas turbine, a steam turbine, or a compressor, in which a fluid high pressure side 11 and a fluid low pressure side in the axial direction of the rotating shaft 10 are used. It seals between the side 12 and the side 12. The shaft sealing device 1 includes an annular housing 20 provided around the rotating shaft 10, and the inside of the housing 20 is opened so as to face the rotating shaft 10 and extends in the circumferential direction of the rotating shaft 10. The accommodation space 21 is formed. The shaft sealing device 1 includes a sealing piece laminated body 2 in the accommodation space 21. As shown in FIG. 2, the seal piece laminated body 2 has an annular structure in which a plurality of thin plate seal pieces 3 are laminated in the circumferential direction of the rotation shaft 10.

As shown in FIG. 3, the thin plate seal piece 3 includes a rectangular body portion 3c extending from one end portion 3a toward the other end portion 3b and the other end portion 3b, and has a width larger than the width of the body portion 3c. It is provided with a rectangular head portion 3d having a rectangular shape, and a rectangular neck portion 3e that connects the body portion 3c and the head portion 3d and has a width smaller than the width thereof. A pair of constricted portions 3f and 3g are configured so as to sandwich the neck portion 3e between the body portion 3c and the head portion 3d.

As shown in FIG. 4, the plurality of laminated thin plate seal pieces 3 are connected by welding the head 3d to form the seal piece laminated body 2. In the seal piece laminated body 2, one end portion 3a of each thin plate seal piece 3 is a free end. When a plurality of thin plate seal pieces 3 are laminated, one end 3a, the other end 3b, the head 3d, the constriction 3f (see FIG. 3), and the constriction 3g (see FIG. 3) of each thin plate seal piece 3 are formed. Consists of an inner peripheral edge 2a, an outer peripheral edge 2b, a supported portion 31, a fluid high-pressure gutter portion 32, and a fluid low-pressure gutter 33, respectively.

The supported portion 31 located on the outer peripheral edge 2b side of the seal piece laminate 2 has a ring-shaped high-pressure side retainer 34 and a ring-shaped high-pressure side retainer 34 having a U-shaped cross section from each of the fluid high-pressure side 11 and the fluid low-pressure side 12. It is sandwiched by the low pressure side retainer 35. The surfaces of the high-pressure side retainer 34 and the low-pressure side retainer 35 facing the seal piece laminate 2 are on the inner side surfaces 34a and 35a facing the width direction of the seal piece laminate 2 and the outer peripheral edge 2b of the seal piece laminate 2, respectively. It has inner bottom surfaces 34b and 35b facing toward each other, and inner top surfaces 34c and 35c facing toward the inner peripheral edge 2a of the seal piece laminate 2. An annular plate-shaped covering member 37 is integrally formed on the high-pressure side retainer 34.

With the high-pressure side retainer 34 and the low-pressure side retainer 35 sandwiching the supported portion 31, the side surface 31c of the fluid high-pressure side 11 and the side surface 31d of the fluid low-pressure side 12 of the supported portion 31 hit the inner side surfaces 34a and 35a, respectively. The inner peripheral edge 31a of the supported portion 31 comes into contact with each other and abuts on the inner bottom surfaces 34b and 35b, respectively. Further, as shown in FIG. 1, the covering member 37 extends from the high-pressure side retainer 34 toward the inner peripheral edge 2a side of the seal piece laminated body 2, and the inner peripheral edge 37a of the covering member 37 and the low-pressure side retainer 35. The inner peripheral edges 35d are in contact with the support surfaces 22 and 23, which are part of the inner surface defining the accommodation space 21 in the housing 20, respectively. In such an embodiment, the supported portion 31 is sandwiched between the high-pressure side retainer 34 and the low-pressure side retainer 35, so that the seal piece laminated body 2 is supported by the housing 20 in the accommodation space 21.

As shown in FIG. 4, when the supported portion 31 is sandwiched between the high-pressure side retainer 34 and the low-pressure side retainer 35, the thin sheet annular back leaf 36 is sandwiched between the seal piece laminate 2 and the low-pressure side retainer 35. And is fixed to the seal piece laminated body 2. An insertion step portion 36a configured to be thicker than the other portions is formed on the outer peripheral edge portion of the back leaf 36, and the seal piece is laminated in a state where the insertion step portion 36a is inserted into the fluid low pressure gutter 33. The back leaf 36 is fixed to the seal piece laminated body 2 so as to be sandwiched between the body 2 and the low pressure side retainer 35.

As shown in FIG. 1, the back leaf 36 is continuously in contact with the side surface 2d of the fluid low pressure side 12 of the seal piece laminate 2 over the entire circumference of the rotating shaft 10. The covering member 37 is not in contact with the side surface 2c of the fluid high pressure side 11 of the seal piece laminate 2, and a continuous gap 38 is formed between the covering member 37 and the side surface 2c over the entire circumference of the rotating shaft 10. ing.

The width of the gap 38 is preferably as small as possible. However, as shown in FIG. 5, waviness occurs on the side surfaces 2c and 2d of the seal piece laminate 2 due to the production of the seal piece laminate 2. This swell generally increases toward the inner peripheral edge 2a side of the seal piece laminated body 2. Therefore, the width of the gap 38 near the high-pressure side retainer 34 (see FIG. 4) is set to about (X _max + α) by setting a margin α (mm) to the maximum value X _max (mm) of the swell. Even in the portion where the side surface 2c is wavy, a width corresponding to the margin α can be secured in the gap 38. Further, the width of the gap 38 near the high-pressure side retainer 34 is set to a margin α, and the width of the gap 38 increases from the high-pressure side retainer 34 toward the inner peripheral edge 37a of the covering member 37 by about the maximum value X _max of the swell. In addition, the first surface 37b of the covering member 37 facing the side surface 2c may be inclined.

As shown in FIG. 1, the inner peripheral edge 37a of the covering member 37 supports the housing 20 after ensuring the width of the gap 38 in which the covering member 37 and the side surface 2c do not come into contact with each other in consideration of the waviness of the side surface 2c and 2d. It is in contact with the surface 22. Therefore, the fluctuation of the covering member 37 in the axial direction of the rotating shaft 10 is suppressed, and the fluctuation of the width of the gap 38 can be suppressed. As a result, the possibility that the covering member 37 comes into contact with the side surface 2c of the seal piece laminated body 2 can be reduced.

Next, the operation of the shaft sealing device 1 according to the first embodiment will be described.
As shown in FIG. 1, when the rotating machine provided with the rotating shaft 10 is stopped, each thin plate seal piece 3 (see FIG. 3) constituting the seal piece laminated body 2 is applied to the rotating shaft 10 by a predetermined pressurization. Are in contact. When the rotary machine is started and the rotary shaft 10 starts to rotate, one end 3a (see FIG. 3) of each thin plate seal piece 3 and the rotary shaft 10 slide and rub against each other. When the rotation speed of the rotation shaft 10 increases while the one end portion 3a and the rotation shaft 10 slide and rub against each other and reach a predetermined rotation speed, a levitation force acts on each thin plate seal piece 3 due to the dynamic pressure effect, and each thin plate seal is sealed. By forming a minute gap between the piece 3 and the rotating shaft 10, the shaft sealing device 1 seals between the fluid high pressure side 11 and the fluid low pressure side 12.

The shaft sealing device 1 has the same configuration as the side leafless structure in that the covering member 37 is not in contact with the side surface 2c of the sealing piece laminated body 2. As described above, in the shaft seal device having a side leafless structure (see FIG. 13), the thin plate seal piece is pressed against the rotating shaft due to the downflow of the fluid between the adjacent thin plate seal pieces. There was a problem that wear was likely to occur.

However, by making the gap 38 between the covering member 37 and the side surface 2c of the seal piece laminated body as small as possible, it becomes difficult for the fluid to flow into the gap 38, so that the fluid is reduced between the adjacent thin plate seal pieces 3. It is possible to reduce the generation of flow and prevent the thin plate seal piece 3 from coming into contact with the rotating shaft 10 when the rotating shaft 10 is rotated. That is, when the rotating shaft 10 is rotated, a minute gap can be surely formed between each thin plate seal piece 3 and the rotating shaft 10. Further, since the gap 38 is formed between the cover member 37 and the side surface 2c of the seal piece laminate 2, the thin plate seal piece 3 and the cover member 37 slide when the thin plate seal piece 3 floats. There is no such thing. In this way, wear of the covering member 37 and the thin plate seal piece 3 can be avoided, and the thin plate seal piece 3 can be prevented from coming into contact with the rotary shaft 10 when the rotary shaft 10 is rotated, so that wear of the thin plate seal piece 3 is suppressed. can do.

In the first embodiment, as shown in FIG. 1, neither the high-pressure side retainer 34 nor the covering member 37 is in contact with the side surface 2c of the seal piece laminated body 2 continuously over the entire circumference of the rotating shaft 10. However, it is not limited to this form. For example, as shown in FIG. 6, a protruding portion 34e formed so as to project from the covering member 37 toward the side surface 2c of the seal piece laminated body 2 is formed in the innermost portion in the radial direction of the high-pressure side retainer 34. However, the protruding portion 34e may be in contact with the outer peripheral edge portion of the side surface 2c.

Further, the seal piece laminated body 2 may be formed with a notch portion 2e notched so as to incline toward the fluid low pressure side 12 from a position near the inner peripheral edge 2a of the side surface 2c to the inner peripheral edge 2a. The notch 2e can improve the floating effect of the thin plate seal piece 3 (see FIG. 3). The cutout portion 2e may be formed in the seal piece laminated body 2 of the shaft sealing device 1 shown in FIG.

In the first embodiment, as shown in FIG. 1, the distance between the inner peripheral edge 37a of the covering member 37 and the axial center L of the rotating shaft 10 is D1, and the distance between the inner peripheral edge 36b of the back leaf 36 and the axial center L of the rotating shaft is L. If the distance is defined as D2, D1> D2, D1 <D2, or D1 = D2 may be used. However, as a result of the study by the present inventors, it was found that the condition of D1> D2 can suppress the vibration of the thin plate seal piece 3 more than the other conditions.

(Embodiment 2)
Next, the shaft sealing device according to the second embodiment will be described. The shaft sealing device according to the second embodiment is a modification of the first embodiment in which the configuration of the covering member 37 is changed. In the second embodiment, the same reference numerals as those of the configuration requirements of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 7, in the shaft sealing device 1 according to the second embodiment of the present disclosure, the inner peripheral edge 34d of the high-pressure side retainer 34 is a support surface 22 which is a part of the inner surface defining the accommodation space 21 in the housing 20. Is in contact with. The covering member 37 extends from the inner peripheral edge 34d of the high-pressure side retainer 34 toward the inner peripheral edge 2a side of the seal piece laminated body 2. With this configuration, the inner peripheral edge 37a of the covering member 37 becomes free, so that the covering member 37 can be made variable so as to approach the side surface 2c of the seal piece laminated body 2. Hereinafter, some forms that can make the covering member 37 variable will be described.

For example, in a state where there is no axial pressure difference of the rotating shaft 10, the covering member 37 is inclined with respect to the side surface 2c of the seal piece laminated body 2 so that the width of the gap 38 widens toward the inner peripheral edge 37a. .. With this configuration, when a pressure difference in the axial direction of the rotating shaft 10 is applied to the covering member 37, the covering member 37 can be elastically deformed so as to approach the side surface 2c of the seal piece laminated body 2. Even if the covering member 37 is elastically deformed, it is necessary to configure the covering member 37 so that it does not come into contact with the side surface 2c. Other configurations are the same as those in the first embodiment.

In the second embodiment, when the rotating machine is started, a pressure difference in the axial direction of the rotating shaft 10 is generated from the fluid high pressure side 11 toward the fluid low pressure side 12. When this pressure difference is applied to the covering member 37, the covering member 37 is elastically deformed so as to approach the side surface 2c of the seal piece laminated body 2. In this way, the width of the gap 38 between the covering member 37 and the side surface 2c of the seal piece laminated body 2 can be adjusted to be smaller according to the pressure difference in the axial direction of the rotating shaft 10.

The configuration in which the covering member 37 can be deformed so as to approach the side surface 2c of the seal piece laminated body 2 is not limited to the configuration shown in FIG. 7. For example, as shown in FIG. 8, the covering member 37 may be configured to become thinner toward the inner peripheral edge 2a side of the seal piece laminated body 2, that is, toward the inner peripheral edge 37a of the covering member 37. In this case, when no pressure is applied to the covering member 37, the first surface 37b of the covering member 37 facing the side surface 2c is configured such that the width of the gap 38 widens toward the inner peripheral edge 37a. With this configuration, the covering member 37 is more likely to be elastically deformed toward the inner peripheral edge 37a side, so that the covering member 37 can be easily changed so as to approach the side surface 2c of the seal piece laminated body 2 due to the pressure difference. It should be noted that the covering member 37 of the shaft sealing device 1 shown in FIG. 7 may be configured to become thinner toward the inner peripheral edge 37a.

Further, for each of the shaft sealing devices 1 shown in FIGS. 7 and 8, the distance D1 (see FIG. 1) between the inner peripheral edge 37a of the covering member 37 and the axial center L of the rotating shaft 10 is set to the inner peripheral edge of the back leaf 36. By making the distance D2 (see FIG. 1) between 36b and the axis L of the rotating shaft 10 smaller (D1 <D2), the length of the covering member 37 becomes longer, and the covering member 37 is closer to the inner peripheral edge 37a side. Can be easily elastically deformed.

Further, the deformation of the covering member 37 so as to approach the side surface 2c of the seal piece laminated body 2 is not limited to the configuration caused by the pressure difference in the axial direction of the rotating shaft 10. For example, as shown in FIG. 9, thermal expansion of the metal forming the covering member 37 on the second surface 37c opposite to the first surface 37b of the covering member 37 facing the side surface 2c of the seal piece laminated body 2. A plate member 40 made of metal having a coefficient of thermal expansion different from the coefficient may be attached.

In the shaft sealing device 1 shown in FIG. 9, when the fluid temperature around the rotating shaft 10 rises after the rotating machine is started, the temperatures of the plate member 40 and the covering member 37 rise. If the coefficient of thermal expansion of the metal constituting each of the plate member 40 and the covering member 37 is different, the degree of deformation of both is different, so that the covering member 37 can be deformed so as to approach the side surface 2c. The plate member 40 can also be attached on the first surface 37b of the covering member 37 by selecting a metal having an appropriate coefficient of thermal expansion.

(Embodiment 3)
Next, the shaft sealing device according to the third embodiment will be described. The shaft sealing device according to the third embodiment is a separate body of the covering member 37 and the high-pressure side retainer 34 from the second embodiment. In the third embodiment, the same reference numerals as those of the configuration requirements of the second embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 10, in the third embodiment of the present disclosure, the covering member 37 and the high-pressure side retainer 34 are configured separately, and the covering member 37 is movably attached to the high-pressure side retainer 34. There is.

In the high-pressure side retainer 34, an engagement space 50 that opens at the inner peripheral edge 34d of the high-pressure side retainer 34 is formed. The covering member 37 includes an engaging portion 51 that protrudes from the outer peripheral edge 37d of the covering member 37 and is formed so as to be inserted into the engaging space 50. By inserting the engaging portion 51 into the engaging space 50, the covering member 37 is attached to the high-pressure side retainer 34. With the engaging portion 51 inserted in the engaging space 50, the distance 52 in the axial direction of the rotating shaft 10 (see FIG. 1) is between the inner surface 50a in the engaging space 50 and the engaging portion 51. Is open. With this configuration, the covering member 37 can be moved in the axial direction of the rotating shaft 10 (direction of arrow A), so that the covering member 37 can be moved to the side surface 2c of the seal piece laminated body 2 by the pressure difference in the axial direction of the rotating shaft 10. It can be moved so as to be closer to, and the width of the gap 38 can be adjusted to be smaller.

In order to prevent the covering member 37 from being brought closer to the side surface 2c when the covering member 37 is moved toward the side surface 2c of the seal piece laminate 2, that is, to maintain the gap 38 within a certain width. In addition, it is preferable to configure the engaging space 50 so that the engaging portion 51 abuts on the inner surface 50a in the engaging space 50. In this case, the inner surface 50a with which the engaging portion 51 abuts constitutes a stopper that restricts the movement of the covering member 37 toward the side surface 2c. The position of the inner surface 50a with which the engaging portion 51 abuts is preferably adjusted to a position where the gap 38 has a preferable width. As another example of the stopper, the stopper may be provided outside the engaging space 50 and may be configured to restrict the movement of the covering member 37 by abutting the covering member 37.

The configurations of the engaging space 50 and the engaging portion 51 are not limited to the configuration shown in FIG. For example, as shown in FIG. 11, the engaging portion 51 is rotated from a first portion 51a that protrudes from the outer peripheral edge 37d of the covering member 37 and extends in the length direction of the covering member 37, and an end portion of the first portion 51a. A first portion 51b having a second portion 51b extending in the axial direction of the shaft 10 (see FIG. 1) is configured to have an L-shaped cross-sectional shape, and the engagement space 50 can be inserted into the first portion 51a. It may be configured to have a space portion 50b and a second space portion 50c into which the second portion 51b can be inserted. In this case, there is a gap 52 between the inner surface of the first space portion 51a and the inner surface of the first space portion 50b, and between the inner surface of the second portion 51b and the second space portion 50c.

Even in the configuration shown in FIG. 11, the covering member is formed by contacting at least one of the first portion 51a or the second portion 51b with at least one part of the inner surface of the first space portion 50b or the inner surface of the second space portion 50c. Since the movement of the 37 can be restricted, at least a part of the inner surface of the first space portion 50b or the inner surface of the second space portion 50c can be used as a stopper. Further, as in the case of FIG. 10, a stopper can be provided outside the engaging space 50 and has a structure that restricts the movement of the covering member 37 by abutting the covering member 37.

1 Shaft sealing device 2 Seal piece laminate 2a Inner peripheral edge 2b (of seal piece laminate) Outer peripheral edge 2c (of seal piece laminate) Side surface 2d (of seal piece laminate) Side surface 2e Notch 3 Thin plate seal piece 3a (thin plate seal piece) one end 3b (thin plate seal piece) other end 3c (thin plate seal piece) body 3d (thin plate seal piece) head 3e (thin plate seal piece) neck 3f Constriction 3g Constriction 10 Rotating shaft 11 Fluid high pressure side 12 Fluid low pressure side 20 Housing 21 Accommodation space 22 Support surface 23 Support surface 31 Supported part 31a (supported part) Inner peripheral edge 31c (supported part) Side surface 31d ( Side surface 32 (of the supported part) Fluid high pressure side groove 33 Fluid low pressure side groove 34 High pressure side retainer 34a Inner side surface 34b (of the high pressure side retainer) Inner bottom surface 34c (of the high pressure side retainer) Inner top surface 34d (of the high pressure side retainer) Inner peripheral edge 34e of high pressure side retainer) Protruding part 35 Low pressure side retainer 35a Inner side surface 35b (of low pressure side retainer) Inner bottom surface 35c (of low pressure side retainer) Inner top surface 36 Back leaf 36a Insertion step portion 36b Inner peripheral edge 37 (of back leaf) Inner peripheral edge 37a (of covering member) Inner peripheral edge 37b (of covering member) First surface 37c (of covering member) Second surface 37d (of covering member) Outer peripheral edge 38 Gap 40 Plate member 50 Engagement space 50a Inner surface (stopper) of the engagement space (engagement space)
50b 1st space part 50c 2nd space part 51 Engagement part 51a 1st part 51b 2nd part 52 Interval L (rotation axis) axis

Claims (13)

A shaft sealing device that seals between the fluid high pressure side and the fluid low pressure side in the axial direction of the rotating shaft.
A seal piece laminate including a plurality of thin plate seal pieces laminated in the circumferential direction of the rotation axis, and
A high-pressure side retainer and a low-pressure side retainer that support the seal piece laminate by sandwiching the outer peripheral edge side of the seal piece laminate from each of the fluid high-pressure side and the fluid low-pressure side.
A plate-shaped covering member that is supported by the high-pressure side retainer and extends from the high-pressure side retainer toward the inner peripheral edge side of the seal piece laminate, and is a side surface of the seal piece laminate on the fluid high-pressure side. A covering member that forms a continuous gap over the entire circumference of the rotating shaft ,
It is configured separately from the low-pressure side retainer, is fixed by being sandwiched between the low-pressure side retainer and the seal piece laminate, and extends from the low-pressure side retainer toward the inner peripheral edge side of the seal piece laminate. A plate-shaped back leaf with a back leaf configured to be in contact with the side surface of the seal piece laminate on the low pressure side of the fluid.
Equipped with
When the distance between the inner peripheral edge of the covering member and the axis of the rotating shaft is defined as D1, and the distance between the inner peripheral edge of the back leaf and the axial center of the rotating shaft is defined as D2, the relationship D1> D2 is satisfied. Shaft sealing device. The shaft sealing device further includes a housing for accommodating the sealing piece laminate, the high pressure side retainer, the low pressure side retainer, and the covering member.
The shaft sealing device according to claim 1, wherein the covering member is integrally configured with the high-pressure side retainer, and the inner peripheral edge of the covering member is configured to abut on a support surface of the housing. A shaft sealing device that seals between the fluid high pressure side and the fluid low pressure side in the axial direction of the rotating shaft.
A seal piece laminate including a plurality of thin plate seal pieces laminated in the circumferential direction of the rotation axis, and
A high-pressure side retainer and a low-pressure side retainer that support the seal piece laminate by sandwiching the outer peripheral edge side of the seal piece laminate from each of the fluid high-pressure side and the fluid low-pressure side.
A plate-shaped covering member that is supported by the high-pressure side retainer and extends from the high-pressure side retainer toward the inner peripheral edge side of the seal piece laminate, and is a side surface of the seal piece laminate on the fluid high-pressure side. A covering member that forms a continuous gap over the entire circumference of the rotating shaft,
A housing for accommodating the seal piece laminate, the high-pressure side retainer, the low-pressure side retainer, and the covering member.
Equipped with
A shaft sealing device in which the covering member is integrally configured with the high-pressure side retainer and the inner peripheral edge of the covering member is in contact with a support surface of the housing. The shaft sealing device according to claim 2 or 3, wherein the gap is configured to increase from the high-pressure side retainer toward the inner peripheral edge of the covering member. The shaft sealing device further includes a housing for accommodating the sealing piece laminate, the high pressure side retainer, the low pressure side retainer, and the covering member.
The covering member is integrally configured with the high pressure side retainer.
The shaft sealing device according to claim 1, wherein the high-pressure side retainer is configured to abut on a support surface of the housing. A shaft sealing device that seals between the fluid high pressure side and the fluid low pressure side in the axial direction of the rotating shaft.
A seal piece laminate including a plurality of thin plate seal pieces laminated in the circumferential direction of the rotation axis, and
A high-pressure side retainer and a low-pressure side retainer that support the seal piece laminate by sandwiching the outer peripheral edge side of the seal piece laminate from each of the fluid high-pressure side and the fluid low-pressure side.
A plate-shaped covering member that is supported by the high-pressure side retainer and extends from the high-pressure side retainer toward the inner peripheral edge side of the seal piece laminate, and is a side surface of the seal piece laminate on the fluid high-pressure side. A covering member that forms a continuous gap over the entire circumference of the rotating shaft,
A housing for accommodating the seal piece laminate, the high-pressure side retainer, the low-pressure side retainer, and the covering member.
Equipped with
The covering member is integrally configured with the high pressure side retainer.
The high-pressure side retainer is a shaft sealing device configured to abut on the support surface of the housing. The shaft sealing device according to claim 5 or 6 , wherein the covering member is configured to approach the side surface of the seal piece laminated body on the fluid high pressure side by a pressure difference in the axial direction. The covering member is integrally configured with the high-pressure side retainer and is elastically deformable by the pressure difference.
The covering member is inclined with respect to the side surface of the seal piece laminate on the fluid high pressure side so that the gap widens toward the inner peripheral edge side of the seal piece laminate when there is no pressure difference. The shaft sealing device according to claim 7 . The covering member is integrally configured with the high-pressure side retainer and is elastically deformable by the pressure difference.
The shaft sealing device according to claim 7 or 8 , wherein the covering member is configured to become thinner toward the inner peripheral edge side of the seal piece laminated body. The covering member is integrally formed with the high-pressure side retainer, and the covering member is formed on a first surface facing the seal piece laminate or on a second surface opposite to the first surface. The shaft sealing device according to claim 5 or 6 , further comprising a plate member made of a metal having a coefficient of thermal expansion different from the coefficient of thermal expansion of the metal to be used. A shaft sealing device that seals between the fluid high pressure side and the fluid low pressure side in the axial direction of the rotating shaft.
A seal piece laminate including a plurality of thin plate seal pieces laminated in the circumferential direction of the rotation axis, and
A high-pressure side retainer and a low-pressure side retainer that support the seal piece laminate by sandwiching the outer peripheral edge side of the seal piece laminate from each of the fluid high-pressure side and the fluid low-pressure side.
A plate-shaped covering member that is supported by the high-pressure side retainer and extends from the high-pressure side retainer toward the inner peripheral edge side of the seal piece laminate, and is a side surface of the seal piece laminate on the fluid high-pressure side. A covering member that forms a continuous gap over the entire circumference of the rotating shaft,
A housing for accommodating the seal piece laminate, the high-pressure side retainer, the low-pressure side retainer, and the covering member.
Equipped with
The covering member is configured separately from the high-pressure side retainer.
The high pressure side retainer is configured to abut on the support surface of the housing.
The covering member is configured to approach the side surface of the seal piece laminate toward the fluid high pressure side by the pressure difference in the axial direction.
An engaging space is formed in the high-pressure side retainer, the covering member has an engaging portion that can be inserted into the engaging space, and the engaging portion is inserted into the engaging space. Then, the covering member is attached to the high pressure side retainer, and the cover member is attached.
With the engaging portion inserted in the engaging space, a shaft sealing device in which an inner surface in the engaging space and the engaging portion are spaced apart in the axial direction of the rotating shaft. .. 11. The 11 . Shaft sealing device. A rotary machine provided with the shaft sealing device according to any one of claims 1 to 12 .

Images