JP2008106823A - Seal structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a seal structure capable of improving seal performance while suppressing plastic deformation of seal rings in a seal structure for inserting the seal rings onto a rotating shaft to be inserted into a bush. <P>SOLUTION: The seal rings 32 are fit onto the rotating shaft 29 via abutment joints 32b and they are laminated in an axial direction. A protruding part 32c is formed on each of the seal rings, and by fitting the protruding part 32c on each abutment joint 32b, relative rotation of each seal ring 32 around the rotating shaft 29 is regulated in a state with the abutment joints 32b arranged in different positions in a circumferential direction of the rotating shaft 29. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a seal structure that seals between an outer peripheral surface of a rotating shaft and an inner peripheral surface of a bush through which the rotating shaft is inserted.

As such a rotary shaft seal structure, for example, in a turbocharger of a vehicle, a structure applied to a variable nozzle mechanism that adjusts the amount of exhaust that collides with the turbine is known. In this variable nozzle mechanism, the opening degree of the opening communicating with the turbine housing provided with the turbine is adjusted by rotating the nozzle vane around the rotation axis. In order to prevent the exhaust gas from leaking through the gap between the bush of the center housing and the rotating shaft, an annular seal ring having elasticity formed in the rotating shaft is inserted. The described turbocharger employs the following configuration. That is, the rotary shaft of the variable nozzle mechanism is formed so that the end portion has a smaller diameter than other parts, and the seal ring is in contact with a step caused by the difference in diameter. Is inserted into. The other end face of the seal ring is pressed by a link member that rotates the rotating shaft. The outer diameter of the seal ring is slightly larger than the inner diameter of the bush, and when fitted, the entire ring is elastically deformed in the radial direction and is press-fitted into the bush. Always pressed down. Therefore, gas leakage such as exhaust is suppressed by the seal ring closing the gap between the rotating shaft and the bush.
Japanese Utility Model Publication 4-15953

  By the way, in the structure which provides the seal ring mentioned above not in the edge part of a rotating shaft but in the center vicinity, for example, it is necessary to insert, sliding on a rotating shaft until it reaches the center of a rotating shaft. Since the seal ring is provided in such a manner that it is press-fitted into the rotary shaft in order to ensure the sealing inside the bush, it is necessary to perform this press-fitting operation while increasing the inner diameter of the seal ring. When the applied load is large, the seal ring is plastically deformed by this stress, and the flexibility thereof is lost. As a result, the sealing performance may be deteriorated. Here, if the diameter of the rotating shaft is narrowed and the seal ring is easily inserted, the strength of the rotating shaft will decrease.Therefore, while securing the strength of the rotating shaft to the extent that it can withstand the stress caused by the rotation, The following configuration is conceivable for insertion into the center of the rotating shaft. That is, a seal ring formed in a substantially C shape is fitted into the central portion of the rotating shaft while expanding the joint. However, even in this case, it is necessary to elastically deform the seal ring when the seal ring is fitted. Therefore, if the deformation amount is large, the seal ring is plastically deformed. On the other hand, if the thickness of the seal ring is reduced in order to relieve the stress generated in the seal ring due to elastic deformation, the contact area with the bush is reduced and the sealing performance is lowered. In other words, there is still room for improvement even with such a configuration in order to achieve both suppression of plastic deformation of the seal ring and improvement of the sealing performance, and such a problem remains in seals other than the variable nozzle mechanism. Even a structure can occur similarly.

  The present invention has been made in view of the above circumstances, and a problem thereof is a seal structure in which a seal ring is inserted into a rotary shaft that is inserted into a bush, and the plastic deformation of the seal ring is suppressed. An object is to realize a seal structure capable of improving the sealing performance.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a seal structure that seals between an outer peripheral surface of a rotating shaft and an inner peripheral surface of a bush through which the rotating shaft is inserted. A pair of seal rings that are externally fitted to each other through a joint and are laminated in the axial direction thereof, and the respective joints of the pair of seal rings are arranged at different positions in the circumferential direction of the rotating shaft, and the seal rings The gist of the invention is to include a regulating means for regulating relative rotation around the rotation axis.

  According to this configuration, the pair of seal rings that are externally fitted to the rotating shaft are stacked in the axial direction of the rotating shaft in a state where their joints are arranged at different positions in the circumferential direction of the rotating shaft. For this reason, even if a fluid such as exhaust gas or fuel enters the joint of one seal ring, the movement of the rotary shaft in the axial direction is restricted by the other seal ring. Therefore, even if the gap between the joints is increased so that the seal ring can be easily fitted to the rotating shaft, the sealing performance will not be significantly reduced. It is possible to achieve compatibility with sex.

  Incidentally, as a regulating means for regulating the relative rotation between the pair of seal rings in this way, for example, according to the invention described in claim 2, the convex portions and the concave portions formed in the pair of seal rings are fitted. By restricting the relative rotation of the two seal rings, or by fitting the seal rings with the bushes according to the uneven relationship, the relative rotation of the two seal rings is controlled. A restricting configuration can be employed.

  According to a third aspect of the present invention, in the seal structure according to the second aspect, the convex portion is fitted into the concave portion by using a joint of a seal ring stacked on each of the pair of seal rings as the concave portion. The gist is to be formed into a possible shape.

  According to this configuration, in a state where the seal ring is attached to the rotating shaft, the convex portion is fitted into the joint and the gap is closed, so that the sealing performance by the seal ring can be further improved. By the way, when the seal ring is press-fitted into the housing, the gap at the joint is reduced due to the pressure received at this time, and in this case, the joint and the convex portion are in the state before the seal ring is press-fitted into the housing. It is desirable that a slight gap be formed between them.

  According to a fourth aspect of the present invention, in the seal structure according to the third aspect, the convex portion and the abutment face each other across the axis of the rotation shaft in a state where each seal ring is attached to the rotation shaft. The gist is that they are formed at the respective positions.

According to the configuration, the same type of seal ring can be fitted to the corresponding joint with the surface from which the convex portion protrudes facing, so that the seal ring can be shared.
In order to solve the above-mentioned problem, the invention according to claim 6 is a seal structure for sealing between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the bush through which the rotating shaft is inserted. The rotary shaft is composed of a plurality of divided bodies divided in the circumferential direction, and a pair of seal rings stacked in the axial direction of the rotary shaft, and a divided surface of each of the pair of seal rings is the rotation shaft. The gist of the present invention is to provide a regulating means for regulating relative rotation of each seal ring around the rotation axis in a state where the seal rings are arranged at different positions in the circumferential direction.

  According to this configuration, the split surfaces of the seal ring are arranged at different positions in the circumferential direction of the rotating shaft. For this reason, even if fluid such as exhaust gas or fuel enters the gap between the split surfaces of one seal ring, the axial movement of the rotary shaft is restricted by the seal ring adjacent to this in the axial direction of the rotary shaft. Will come to be. Therefore, even if the seal ring is made small, for example, smaller than a semicircle, so that the seal ring can be easily fitted on the rotating shaft, the seal performance will not be greatly reduced. It is possible to achieve both sealing performance and ease of assembly with respect to the rotating shaft.

  Incidentally, as a restricting means for restricting the relative rotation between the pair of seal rings in this way, for example, as in the case of claim 7, the convex portions and the concave portions formed in the pair of seal rings are fitted. Therefore, the relative rotation of the two seal rings is regulated by fitting the seal rings and the bushes in a concave-convex relationship, as in the configuration for regulating the relative rotation of the two seal rings. A configuration can be employed.

  The invention according to claim 9 is the seal structure according to any one of claims 1 to 3 and 5 to 8, wherein the seal ring overlapped in the axial direction of the rotary shaft has an inner diameter of the bush. The gist of the present invention includes a large-diameter seal ring having a relatively small clearance with respect to the outer diameter of the rotary shaft and a small-diameter seal ring having a relatively small clearance with respect to the outer diameter of the rotating shaft.

  According to this configuration, the large and small seal rings are mounted so as to overlap in the axial direction of the rotating shaft, and the passage through which fluid such as exhaust passes is in a labyrinth shape and the amount of leakage is reduced, so that the sealing performance can be further improved. become able to.

  A tenth aspect of the present invention is the seal structure according to any one of the first to ninth aspects, wherein the rotating shaft is driven when the nozzle opening is changed in a variable nozzle mechanism of a turbocharger of an internal combustion engine. It is a drive shaft, and the gist of the invention is that the seal ring is provided between the drive shaft and a bush that is provided in a housing of the turbocharger and rotatably supports the drive shaft.

  According to this configuration, it is possible to suitably suppress the exhaust gas from leaking out of the housing through the gap between the drive shaft and the bush from the inside of the turbocharger.

(First embodiment)
Hereinafter, a first embodiment in which a seal structure of a rotating shaft of the present invention is applied to a variable nozzle mechanism for adjusting a flow rate of exhaust gas blown to a turbine wheel of a turbocharger will be described with reference to FIGS. To do. FIG. 1 shows a sectional structure of this variable nozzle turbocharger.

  As shown in FIG. 1, the rotor shaft 3 of the variable nozzle turbocharger 1 is rotatably supported by a housing 2. A compressor wheel 7 and a turbine wheel 8 are respectively attached to each end of the rotor shaft 3, and a scroll communicating with an exhaust passage extending from the exhaust port of the combustion chamber is connected to the turbine wheel 8. Exhaust gas is blown through the passage 10. A nozzle vane 11 for adjusting the opening degree of the passage is provided upstream of the turbine wheel 8 in the scroll passage 10, and the opening degree of the nozzle vane 11 is adjusted by the variable nozzle mechanism 20.

  The variable nozzle mechanism 20 includes a nozzle shaft 21 that can rotate integrally with the nozzle vane 11. The nozzle shaft 21 is rotatably inserted into a ring-shaped nozzle back plate 22 mounted on the housing 2 (only one of them is shown in FIG. 1). In addition, an opening / closing lever 24 that extends toward the outer edge of the nozzle back plate 22 (upward in FIG. 1) perpendicular to the coaxial 21 at the end of each nozzle shaft 21 opposite to the side to which the nozzle vane 11 is connected. Is fixed.

  Further, a ring plate 25 is provided between the opening / closing lever 24 and the nozzle back plate 22 so as to be coaxial with the nozzle back plate 22 so as to be rotatable. The ring plate 25 is provided with a plurality of pins 26 at equal angular intervals along the circumferential direction thereof, and the pins 26 are sandwiched between the open / close levers 24. In this way, the nozzle shaft 21 for each nozzle vane 11 is drivingly connected to the ring plate 25 via the opening / closing lever 24 and the like.

  A drive pin 27 is fixed to the ring plate 25, and a drive lever 28 is fitted to the drive pin 27. A rotation shaft 29 that can rotate integrally with the drive lever 28 is fixed to the drive lever 28. The rotation shaft 29 is rotated by a drive arm 30 driven by an actuator. Therefore, when the actuator operates, the rotation shaft 29 rotates and the ring plate 25 rotates. The rotating shaft 29 is rotatably inserted into a bush 31 that is press-fitted and fixed to the housing 2.

  Then, when the ring plate 25 is rotated around its center by the actuator, each pin 26 pushes each opening / closing lever 24 in the rotation direction of the ring plate 25. As a result, the open / close levers 24 rotate the nozzle shaft 21, and the nozzle vanes 11 open and close in synchronization with each other about the coaxial 21 along with the rotation.

  By driving the nozzle vane 11 in this way, the opening degree of the scroll passage 10 is adjusted. By exhaust gas being blown to the turbine wheel 8 through the scroll passage 10, the turbine wheel 8 is centered on the axis L. Rotate. The rotation of the turbine wheel 8 also rotates the rotor shaft 3 connected thereto, and the compressor wheel 7 rotates around the axis L based on this rotation. By the compressor wheel 7 rotating in this manner, air convected to the intake air inlet 12 is forcibly sent to the intake air passage via the compressor passage 13.

  In addition to such a basic configuration of the variable nozzle turbocharger 1, in the present embodiment, the rotation shaft 29 of the variable nozzle mechanism 20 passes through a gap between the outer peripheral surface and the inner peripheral surface of the bush 31. A seal structure for suppressing leakage of exhaust gas is employed, and this seal structure will be described below with reference to FIGS. 2A shows a sectional structure in the axial direction of the rotating shaft 29 and the bush 31 of the variable nozzle mechanism 20, and FIG. 2B shows the AA line in FIG. 2A. The cross-sectional structure of the rotating shaft 29 etc. along is shown. FIGS. 3A and 3B show how the seal ring 32 that seals between the rotating shaft 29 and the bush 31 is mounted.

  First, as shown in FIG. 2A, the rotating shaft 29 inserted into the bush 31 has a small-diameter portion 29a formed at the center in the axial direction so as to have a smaller diameter than other portions. A pair of seal rings 32 are fitted to the small diameter portion 29a in a state of being laminated in the axial direction. As shown in FIG. 3A, a part of the annular portion 32a is notched in the seal ring 32 to form an abutment 32b, and the width W of the gap of the abutment 32b is equal to that of the small diameter portion 29a. It is set slightly smaller than the diameter. Further, a convex portion 32c is formed to protrude from the top surface (or bottom surface) of the seal ring 32, and this convex portion 32c has substantially the same shape as the joint 32b. The joint 32b and the convex portion 32c are formed at positions facing each other across the axis of the rotation shaft 29, and the pair of seal rings 32 are the same. Then, the pair of seal rings 32 formed in this manner are fitted into the small diameter portion 29a in such a manner that the surfaces on which the convex portions 32c are formed face each other. At this time, as shown in FIG. 3 (b), the protrusion 32 c is fitted into the joint 32 b of each seal ring 32, and the joint 32 b is closed by this fitting. In addition, the relative rotation between the pair of seal rings 32 is restricted by fitting the convex portion 32c and the abutment 32b, and in this embodiment, the convex portion 32c and the abutment 32b cooperate. It functions as a regulation means.

  Incidentally, when the seal ring 32 is externally fitted to the small diameter portion 29a, the width W of the joint 32b of the seal ring 32 is smaller than the diameter of the small diameter portion 29a. Therefore, the annular portion 32a is widened to widen the joint 32b. However, it is necessary to perform the fitting work. In this operation, the larger the width W of the abutment 32b is, the more it becomes unnecessary to widen the annular portion 32a, and the stress acting on the seal ring 32 can be suppressed. On the other hand, when the width W of the abutment 32b is large, fluid such as exhaust or fuel easily enters the gap, which is not preferable from the viewpoint of securing the sealing performance. However, as described above, the small diameter portion 29a of the seal ring 32 is not preferable. Since the joint 32b is closed by the convex portion 32c during fitting into the skirt, a reduction in sealing performance is avoided. Therefore, in the seal structure of the rotating shaft 29 of the present embodiment, the sealing performance is not greatly deteriorated even though the width W of the joint 32b of the seal ring 32 is set large. Both the sealing performance of 32 and the assembling property with respect to the rotating shaft 29 are achieved.

  In addition, as shown with a dashed-dotted line in FIG.3 (b), before insertion to the bush 31, it has a some clearance gap between the abutment 32b of the seal ring 32, and the convex part 32c, When the rotating shaft 29 with the seal ring 32 attached is inserted into the bush 31, the seal ring 32 is press-fitted to close the gap.

The effects of the seal structure according to this embodiment described above will be described below.
(1) A pair of seal rings 32 that are externally fitted to the rotation shaft 29 via the abutment 32 b and stacked in the axial direction are provided, and each abutment 32 b of the pair of seal rings 32 is provided in the circumferential direction of the rotation shaft 29. The relative rotation around the rotation shaft 29 of each seal ring 32 is restricted in a state where the seal rings 32 are arranged at different positions. For this reason, even if fluid such as exhaust gas or fuel enters the joint 32 b of one seal ring 32, the movement of the rotary shaft 29 in the axial direction is restricted by the other seal ring 32. Therefore, even if the gap of the joint 32b is increased so that the seal ring 32 can be easily fitted on the rotation shaft 29, the seal performance is not greatly deteriorated. And assembly with respect to the rotating shaft 29 can be achieved at the same time.

  (2) The convex portion 32c is formed in a shape that can be fitted to the joint 32b of the seal ring 32 laminated on each of the pair of seal rings 32. By constructing the convex portion 32c in this manner, the convex portion 32c is fitted into the joint 32b and the gap is closed in a state where the seal ring 32 is attached to the rotating shaft 29, so that the sealing performance by the seal ring 32 is improved. This can be further improved.

  (3) The convex portion 32 c and the joint 32 b are formed at positions facing each other across the axis of the coaxial 21 in a state where each seal ring 32 is attached to the rotation shaft 29. According to such a configuration, the same kind of seal ring 32 can be fitted to the corresponding abutment 32b with the surface from which the protrusion 32c protrudes facing, and the seal ring 32 can be shared. Can be planned.

(Second Embodiment)
Next, a second embodiment embodying the present invention will be described with reference to FIGS. In the second embodiment, a seal structure different from that of the first embodiment is adopted, and hereinafter, the second embodiment will be described focusing on differences from the first embodiment. 4 shows the cross-sectional structure of the nozzle shaft and the seal ring, and FIGS. 5 (a) and 5 (b) show how the seal ring is mounted to close the space between the rotating shaft and the bush. It is.

  First, as shown in FIG. 5A, in this embodiment, a pair of seal rings 40 and 41 are divided into a plurality of (in this embodiment, two) split bodies 42 to 45 having a substantially semi-annular shape. It is divided. In these divided bodies 42 to 45, bearing portions 42a to 45a corresponding to the small diameter portion 29a are formed. Moreover, these seal rings 40 and 41 are the same, respectively, and it becomes a ring shape by combining each division body 42-45. Further, of the divided bodies 42 to 45, the divided bodies 42 and 44 are provided with convex portions 46 and 47 that are formed so as to protrude from the circumferential surface thereof. The seal rings 40 and 41 formed in this way are fitted into the small diameter portion 29 a so that each of them is laminated in the axial direction of the rotation shaft 29. At this time, when the seal rings 40 and 41 are fitted into the small diameter portion 29a, it is not necessary to expand the bearing portions 42a to 45a of the divided bodies 42 to 45. It is possible to perform the fitting operation without acting. Then, in a state where the seal rings 40 and 41 are externally fitted to the small-diameter portion 29a as described above, the portions where the divided surfaces 42b and 43b of the divided bodies 42 to 45 are in contact with each other and the divided surfaces 44b and 45b are in contact. The parts are arranged at different positions in the circumferential direction of the rotation shaft 29 as shown in FIG. On the other hand, the protrusions 46 and 47 formed to protrude from the divided bodies 42 and 44 are arranged at the same position in the circumferential direction of the rotation shaft 29, and as shown in FIG. The recesses 48 formed at corresponding positions of the bush 31 are fitted. Therefore, the seal rings 40 and 41 are fitted to each other by the unevenness so that the portions where the divided surfaces 42 b to 45 b face each other do not overlap in the circumferential direction of the rotation shaft 29. This restricts the relative rotation of each other. Therefore, for example, even if the exhaust enters the gap between the split surfaces 42b and 43b of the seal ring 40, the seal ring 41 adjacent thereto in the axial direction of the rotary shaft 29 moves in the axial direction of the rotary shaft 29. Will be regulated, and sealing performance will be ensured.

The effects of the seal structure according to this embodiment described above will be described below.
(4) Since the split surfaces 42b to 45b of the seal rings 40 and 41 are arranged at different positions in the circumferential direction of the rotating shaft 29, the gaps between the split surfaces 42b to 45b of one seal ring 40 or 41 are provided. Even if fluid such as exhaust gas or fuel enters, the movement of the rotary shaft 29 in the axial direction is restricted by this and the other seal ring. Therefore, even if the divided bodies 42 to 45 of the seal rings 40 and 41 are formed in a substantially semi-annular shape so as to be easily fitted to the rotation shaft 29, the sealing performance is not greatly deteriorated. Thus, it is possible to achieve both the sealing performance of the seal rings 40 and 41 and the assembling property with respect to the rotating shaft 29.

The first and second embodiments can be implemented with appropriate modifications as follows.
In each of the above embodiments, the seal ring having the same shape is stacked and externally fitted to the rotation shaft 29. However, for example, a seal structure as shown in FIG. 6 may be employed. That is, as shown in FIG. 6, a large-diameter seal ring 51 having a relatively small clearance with respect to the inner diameter of the bush 31 and a small-diameter seal ring having a relatively small clearance with respect to the outer diameter of the rotating shaft 29. 52 are stacked in the axial direction and are externally fitted to the rotary shaft 29. As described above, since the large and small seal rings 51 and 52 are mounted so as to overlap each other in the axial direction of the rotation shaft 29, the passage through which the exhaust passes becomes a labyrinth shape and the amount of leakage is reduced, thereby further improving the sealing performance. To be able to. In the above configuration, as the large and small seal rings 51 and 52, those described in the following modified examples can be adopted in addition to those shown in the first and second embodiments.

  In the second embodiment, the relative rotation of the seal rings 40 and 41 is restricted by the fitting of the seal rings 40 and 41 and the bush 31. However, as shown in FIG. , 41 may be formed with a convex portion 46a and a concave portion 48a, and these may be fitted to each other. Alternatively, it is possible to adopt a configuration in which a concave portion is formed in the seal ring 40 and a convex portion is formed in the bush 31 and the concave and convex portions are fitted to restrict relative rotation of the seal ring. In addition, it is not necessary to use the same fitting structure for all of the plurality of seal rings. For example, one seal ring is fitted to the bush by an uneven shape, and the other seal ring is fitted to this bush. A configuration for fitting with a ring can also be employed.

  -In 1st Embodiment, although the convex part 32c and the abutment 32b were comprised so that it might become the mutually same shape, even if a convex part is a shape smaller than the abutment 32b, it can be fitted with this. If present, the shape is arbitrary.

  In addition, in the first embodiment, the joint 32b and the convex portion 32c of each seal ring 32 are fitted together, but a convex portion is formed only on one seal ring, which corresponds to this. A configuration that fits into the joint, that is, a configuration in which both joints are not blocked by the convex portion can also be adopted.

  In the first embodiment, the relative rotation of the pair of seal rings 32 is restricted by fitting the convex portion 32c and the joint 32b, but the convex portion is fitted to the joint 32b. Instead, it is possible to employ a configuration in which the seal ring 32 is fitted into a recess formed in the end face.

-Moreover, in the structure which seal rings fit in this way, the structure fitted through the relationship of an unevenness | corrugation as shown, for example in FIG. 8 is also employable.
In the above-described embodiment, the small-diameter portion 29a is formed on the rotating shaft 29 as a part to be externally fitted to the seal ring. However, a configuration in which the small-diameter portion 29a is not formed on the rotating shaft 29 is employed. You can also

-As shown in the said embodiment, the number of seal rings is not limited to two, but the number is arbitrary.
In the above embodiment, the seal structure of the rotating shaft 29 of the variable nozzle mechanism 20 is presented. However, the seal structure of the present invention can also be adopted as a seal structure of other rotating shafts.

FIG. 3 is a cross-sectional view showing an overall configuration of a turbocharger including a variable nozzle mechanism to which the seal structure of the first embodiment is applied. (A) is sectional drawing which shows the state by which the seal ring was similarly fitted to the nozzle axis | shaft in the cross-sectional structure along the axis line, (b) shows the cross-sectional structure along the AA line of (a). Sectional drawing. (A), (b) is a perspective view which similarly shows the mounting aspect of the seal ring to a nozzle shaft. Sectional drawing which shows the state in which the seal ring was fitted by the nozzle axis | shaft in the variable nozzle mechanism to which the seal structure of 2nd Embodiment is applied in the cross-section along a line perpendicular | vertical to the axis. (A), (b) is a perspective view which similarly shows the mounting aspect of the seal ring to a nozzle shaft. Sectional drawing which shows the state by which the seal ring was fitted by the nozzle axis | shaft with the cross-sectional structure along the axis line about the modification of a seal structure. The perspective view which shows the modification of the unevenness | corrugation formed in a seal ring. The top view which shows the modification of the unevenness | corrugation similarly formed in a seal ring.

Explanation of symbols

  L ... axis, 29 ... rotating shaft, 31 ... bush, 32, 40, 41, 51, 52 ... seal ring, 32b ... joint, 32c, 46, 47 ... convex part, 42-45 ... divided body, 42b-45b ... dividing surface, 48 ... concave portion, 51 ... large diameter seal ring, 52 ... small diameter seal ring.

Claims (10)

A seal structure that seals between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the bush through which the rotating shaft is inserted,
A pair of seal rings that are externally fitted to the rotating shaft via a joint and are laminated in the axial direction;
A rotating shaft comprising: a restricting means for restricting relative rotation of each seal ring around the rotating shaft in a state where the joints of the pair of seal rings are arranged at different positions in the circumferential direction of the rotating shaft. Seal structure. The seal structure according to claim 1,
The sealing means includes a convex portion and a concave portion selectively formed on the pair of seal rings, and restricts relative rotation of the pair of seal rings by fitting them. The seal structure according to claim 2,
The said convex part is formed in the shape which can be fitted to this by making into the said recessed part the joint of the seal ring laminated | stacked on each of said pair of seal rings. The seal structure according to claim 3,
The said convex part and the said joint are each formed in the position which opposes on both sides of the axis line of the rotating shaft in the state in which each seal ring was attached to the rotating shaft. The seal structure according to claim 1,
The restricting means restricts relative rotation of the pair of seal rings by fitting each seal ring and the bush according to a concavo-convex relationship. A seal structure that seals between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the bush through which the rotating shaft is inserted,
A pair of seal rings that are configured by a plurality of divided bodies divided in the circumferential direction of the rotating shaft, and are stacked in the axial direction of the rotating shaft;
And a restricting means for restricting relative rotation of each seal ring around the rotation shaft in a state in which divided surfaces of the divided bodies of the pair of seal rings are arranged at different positions in the circumferential direction of the rotation shaft. The rotary shaft seal structure. The seal structure according to claim 6,
The sealing means includes a convex portion and a concave portion selectively formed on the pair of seal rings, and restricts relative rotation of the pair of seal rings by fitting them. The seal structure according to claim 6,
The restricting means restricts relative rotation of the pair of seal rings by fitting each seal ring and the bush according to a concavo-convex relationship. In the seal structure according to any one of claims 1 to 3 and 5 to 8,
The seal ring overlapped in the axial direction of the rotating shaft has a large-diameter seal ring in which the clearance with respect to the inner diameter of the bush is set to be relatively small, and the clearance with respect to the outer diameter of the rotating shaft is set to be relatively small. And a small-diameter seal ring. In the seal structure according to any one of claims 1 to 9,
The rotary shaft is a drive shaft that is driven when the nozzle opening degree is changed in a variable nozzle mechanism of a turbocharger of an internal combustion engine, and the seal ring is provided in a housing of the turbocharger and rotatably supports the drive shaft. The rotary shaft seal structure is provided between the bush and the drive shaft.

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