JP2011153570A - Abradable seal fixing structure of supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To comparatively facilitate of assembly of an abradable seal 20, and to allow rotation resistance of a compressor impeller 2 in the early stage of use to be reduced, in a structure having the abradable seal 20 fixed in a round corner area facing a blade 2a of the compressor impeller 2 on an inner face of an intake path of a compressor housing 4 of a super charger. <P>SOLUTION: In the round corner area, a hollow 10 having a shape emulating that of the abradable seal 20 is provided. The abradable seal 20 is formed such that a flare part 22 is integrally provided on one end in the axial direction of a cylindrical part 21, and the other end in the axial direction of the cylindrical part 21 is pressed in and fitted to a deep side of the area along the axial direction of the hollow 10 and the maximum outer diameter side of the flare part 22 is pressed in and fitted to an outer diameter side inner circumferential surface 13 of an area along a radial direction of the hollow 10 by a retaining ring 30, so that the abradable seal 20 is fixed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a structure for fixing an abradable seal of a supercharger (such as a turbocharger or a supercharger) used in an internal combustion engine (engine) mounted on a vehicle such as an automobile.

  For example, a turbocharger rotationally drives a compressor impeller together with a turbine wheel that is rotationally driven by exhaust gas from an internal combustion engine, and performs an intake air supercharging operation by air compressed by the compressor impeller.

  In such a turbocharger, in order to improve the air compression efficiency, it is preferable to make the clearance between the plurality of blades provided in the compressor impeller and the intake passage inner surface of the compressor housing as small as possible.

  Conventionally, in order to make the clearance between the blade and the inner surface of the intake passage close to zero, an abradable sprayed film is formed on the inner surface of the intake passage, or a machinable member to be cut by a blade of a compressor impeller is attached. Is known (for example, see Patent Document 1).

  In the conventional example according to Patent Document 1, the shroud member 12 as a machinable member is integrally provided with an outlet side portion 16 that extends radially outward at one axial end of a cylindrical inlet side portion 15. It is in shape. The shroud member 12 is attached by press-fitting the cylindrical inlet side portion 15 into the attachment hole 14 of the housing body 13.

  By the way, the conventional example according to Patent Document 2 discloses that a sliding member 15 different from the machinable member as described above is attached to the shroud portion 16 of the compressor housing 9. The sliding member 15 is not scraped by the blade of the compressor impeller.

  By fitting the C-shaped ring 22 across both the annular recess 15a formed on the outer periphery of the sliding member 15 and the annular groove 14a formed in the shroud portion 16 of the compressor housing 9, the sliding member 15 is fitted. Is attached to the compressor housing 9. Furthermore, in such an attached state, the clearance between the sliding member 15 and the blade 13A of the compressor impeller 8 is set so as to be narrower than the clearance between the shroud portion 16 and the blade 13A. The inner surface of 15 is slightly protruded from the shroud portion 16.

Japanese Patent Laid-Open No. 10-331653 Japanese Patent Laid-Open No. 11-173153

  In the conventional example according to Patent Document 1, the shroud member 12 is attached to the housing body 13 of the compressor housing by press-fitting the cylindrical inlet side portion 15 of the shroud member 12 as a machinable member into the attachment hole 14. However, since the entire width of the cylindrical inlet side portion 15 is a press-fitting portion and the press-fitting width is increased, the shroud member 12 is hardly assembled.

  Further, for example, when the shroud member 12 is shaved by the compressor impeller 2, in order to prevent the shroud member 12 from rotating around the housing body 13, it is necessary to set a large press-fitting allowance for the shroud member 12. However, if it does so, it will become difficult to assemble the shroud member 12 further.

  Since the conventional example according to Patent Document 2 uses a sliding member 15 that is different from the machinable member, the slip shown in the conventional example according to Patent Document 2 is different from the technology that is the premise of the present invention. As is well known, the C-type ring 22 used in the attachment structure of the member 15 has an annular shape in order to allow the movement when the C-type ring 22 is attached and to ensure the assembly of the C-type ring 22. It is necessary to fit the recess 15a and the annular groove 14a with play in the axial direction and the radial direction, respectively.

  Therefore, since the sliding member 15 is likely to rattle in the axial direction and the radial direction, there is a concern that the clearance between the sliding member 15 and the blade 13A of the compressor impeller 8 is likely to change. Furthermore, since the sliding member 15 is attached in a state where it can move in the axial direction and the radial direction, when the sliding member 15 undergoes creep deformation (for example, a phenomenon in which plastic deformation increases in the axial direction with time under a certain stress), There is a concern that the shakiness of the sliding member 15, particularly in the axial direction, may be further increased.

  In view of such circumstances, the present invention is a structure in which an abradable seal is fixed to a rounded corner region facing a blade of a compressor impeller on an inner surface of an intake passage of a compressor housing of a turbocharger. It is intended to make it relatively easy and to suppress or prevent creep deformation of the abradable seal.

  The present invention is provided with a recess in which an abradable seal having a shape following the round corner region is fitted in a round corner region facing the blade of the compressor impeller on the inner surface of the intake passage of the compressor housing of the turbocharger. The abradable seal has a shape in which a flare portion is integrally provided on one end of the cylindrical portion in the axial direction, and the abradable seal extends along the axial direction of the recess at the other axial end of the cylindrical portion. By press-fitting and fitting the maximum outer diameter side of the flare portion to the inner peripheral surface of the outer diameter side of the region along the radial direction of the depression by a retaining ring, It is characterized by being fixed.

  In this configuration, the abradable seal is fixed to the recess by press-fitting two axially opposite ends of the abradable seal into the recess on the inner surface of the intake passage.

  This makes it possible to eliminate axial and radial play of the abradable seal with respect to the recess. Moreover, since the press-fitting width of both of the press-fitting parts can be smaller than the conventional example according to Patent Document 1, even if the press-fit tightening margin is set larger than that of the conventional example according to Patent Document 1, The abradable seal can be assembled relatively easily, which is advantageous in increasing the production efficiency of the turbocharger.

  Furthermore, since play in the axial direction and radial direction of the abradable seal can be eliminated, it is possible to suppress or prevent creep deformation of the abradable seal. This makes it easy to design and manage the initial scraping amount of the abradable seal by the compressor impeller, so that the clearance between the abradable seal and the blade of the compressor impeller can be set accurately. Note that creep deformation is a phenomenon in which plastic deformation increases in the axial direction with time under a constant stress, for example.

  Preferably, a recess recessed in the axial direction is provided on the outer diameter side of the inner end of the region along the axial direction of the recess, and the other end in the axial direction of the cylindrical portion of the abradable seal is provided with the shaft in the recess. Protrusions that are press-fitted from the direction are provided.

  Here, one of the two press-fitting portions of the abradable seal is specified, and by this specification, the press-fitting width of the one press-fitting portion is smaller than that of the conventional example according to Patent Document 1. It becomes clear that

  Preferably, a step portion is provided at an outer corner portion of the maximum outer diameter portion of the flare portion of the abradable seal, and the retaining ring is in a state in which the snap ring is externally fitted to the step portion of the abradable seal. By press-fitting to the inner peripheral surface of the outer diameter side of the region along the radial direction of the recess, the thin annular plate portion existing behind the stepped portion of the flare portion is aligned along the radial direction at the bottom surface of the recess. Press on the area.

  Here, of the two press-fitted parts of the abradable seal, the remaining one of the press-fitting forms is specified, and it is clear that the press-fitting width of the remaining one of the press-fitted parts becomes as small as possible. become.

  Preferably, on the outer end side of the region along the radial direction on the bottom surface of the recess, a circumferential groove recessed in the axial direction is provided, and an elastic ring is fitted into the circumferential groove in a compressed state.

  In this configuration, the amount of compression of the elastic ring can be adjusted, so that, for example, the dimensional error between the thickness of the radially outward portion of the flared portion of the abradable seal and the depth of the region along the radial direction of the depression It can be absorbed by the elastic ring.

  If the thickness dimension of the radially outward portion of the flared portion of the abradable seal is smaller than the depth dimension of the recess, the following situation may occur if the elastic ring is not used. That is, when the retaining ring is attached to the recess so that the outer surface of the retaining ring and the inner surface of the intake passage are substantially flush with each other, the area along the radial direction on the bottom surface of the recess and the diameter of the flare portion of the abradable seal There is a possibility that a gap may be formed between the direction outward portion. On the other hand, if the elastic ring as described above is used, the gap can be eliminated.

  Preferably, the inner peripheral surface of the end portion of the cylindrical portion of the abradable seal and the portion excluding the depression in the region along the axial direction of the intake passage inner surface are flush with each other, and the flare portion of the abradable seal The radially outward portion, the retaining ring, and the portion excluding the depression in the region along the radial direction of the inner surface of the intake passage are flush with each other.

  In this configuration, both ends in the axial direction of the abradable seal and the inner surface of the intake passage are flush with each other, so that no step is generated, so that air flow resistance in the intake passage is reduced and air intake efficiency is reduced. It is advantageous to increase

  In the present invention, in the structure in which the abradable seal is fixed to the rounded corner region facing the blade of the compressor impeller on the inner surface of the intake passage of the compressor housing of the turbocharger, the assembly of the abradable seal can be made relatively easy. It becomes possible, and it becomes possible to suppress or prevent creep deformation of the abradable seal.

It is sectional drawing which shows one Embodiment of the abradable seal fixing structure of the supercharger which concerns on this invention. It is a figure which expands and shows a part of FIG. It is a figure which shows the state which isolate | separated the abradable seal in FIG. It is sectional drawing which shows other embodiment of the abradable seal fixing structure of the supercharger which concerns on this invention. It is a figure which expands and shows a part of FIG. It is a figure which shows the state which isolate | separated the abradable seal in FIG. It is a figure which shows the form attached in the state in which the outer-diameter side of the flare part of an abradable seal is not preferable in FIG.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings. 1 to 3 show an embodiment of the present invention. In this embodiment, the case where this invention is applied to the supercharger used for the internal combustion engine mounted in vehicles, such as a motor vehicle, is mentioned as an example.

  In FIG. 1, 1 is a turbine shaft of a supercharger. A turbine wheel (not shown) is integrally provided at one axial end of the turbine shaft 1, and a compressor impeller 2 that is separate from the turbine shaft 1 rotates at the other axial end of the turbine shaft 1. It is attached so as to be integrated.

  The turbine shaft 1 is rotatably supported in a horizontal hole 3a of the bearing housing 3 through a bearing (not shown) such as an appropriate slide bearing or a rolling bearing in a substantially horizontal posture. A turbine housing (not shown) in which the turbine wheel is arranged and a compressor housing 4 in which the compressor impeller 2 is arranged are attached to the bearing housing 3.

  In FIG. 1, reference numeral 5 denotes a seal plate, and 6 denotes an oil deflector for recovering oil supplied to the bearing.

  By the way, a recess 10 is provided in a rounded corner region facing the blade 2 a of the compressor impeller 2 on the inner surface of the intake passage 4 a of the compressor housing 4. An abradable seal 20 is attached to the recess 10.

  The abradable seal 20 has a shape in which a flare portion 22 is integrally provided on one end of the cylindrical portion 21 in the axial direction, and the abradable seal 20 has a shape following the rounded corner region. On the other hand, the recess 10 has a shape that follows the abradable seal 20, and is fitted and mounted in a state where the abradable seal 20 matches the recess 10.

  The abradable seal 20 is installed between the blade 2a of the compressor impeller 2 and the inner surface of the intake passage 4a of the compressor housing 4 and is scraped as the compressor impeller 2 rotates, as is well known. It is used to make the clearance between the blade 2a and the inner surface of the intake passage 4a close to zero.

  As a material of the abradable seal 20, when the compressor housing 4 and the compressor impeller 2 are made of a light alloy such as an aluminum alloy, the blade 2a of the compressor impeller 2 is not easily attacked and damaged, but can be cut relatively easily. In addition, it is preferable to use a machinable material having excellent heat resistance, such as polyimide (PI), polyphenylene sulfide (PPS), or the like.

  The fixing structure of the abradable seal 20 will be described in detail with reference to FIG. 2 and FIG.

  In this embodiment, in order to fix the abradable seal 20 to the recess 10, the other axial end (air inlet side) of the cylindrical portion 21 of the abradable seal 20 is connected to the back of the region along the axial direction of the recess 10. A configuration in which the maximum outer diameter side of the flare portion 22 of the abradable seal 20 is press-fitted and fitted to the outer diameter side inner peripheral surface 13 in the region along the radial direction of the recess 10 by the retaining ring 30. I have to.

  In other words, the abradable seal 20 is fixed to the recess 10 by press-fitting the two axially opposite ends of the abradable seal 20 into the recess 10 in the inner surface of the intake passage 4 a of the compressor housing 4.

  Specifically, an annular recess 11 that is recessed in the axial direction is provided on the outer diameter side of the inner end of the region along the axial direction of the recess 10. By providing the annular recess 11, a flange 12 exists on the inner diameter side of the annular recess 11.

  At the other end in the axial direction of the cylindrical portion 21 of the abradable seal 20, a thin ring-shaped convex portion 23 that is press-fitted into the annular concave portion 11 from the axial direction is provided. In other words, the ring-shaped convex portion 23 is a thin-walled cylindrical portion whose thickness is halved in the cylindrical portion 21 by expanding the inner diameter side of the other axial end of the cylindrical portion 21. In addition, the width dimension along the radial direction of the annular recess 11 is appropriately set larger than the thickness dimension along the radial direction of the ring-shaped convex portion 23, thereby enabling the press-fitting as described above and the press-fitting. The compression rate in the radial direction of the ring-shaped convex portion 23 is managed.

  A step portion 24 is provided at a corner portion on the outer side (the intake passage 4 a side) in the maximum outer diameter portion of the flare portion 22 of the abradable seal 20. By providing this step portion 24, a thin annular plate portion 25 exists at the corner portion inside the maximum outer diameter portion of the flare portion 22 (on the bottom surface side of the recess 10). In other words, the annular plate portion 25 is a portion in which the thickness of the maximum outer diameter portion is halved by removing the outer corner portion of the maximum outer diameter portion of the flare portion 22.

  The retaining ring 30 is fitted on the outer peripheral side inner peripheral surface 13 of the region along the radial direction of the recess 10 in a state where the retaining ring 30 is externally fitted to the stepped portion 24 of the abradable seal 20. The annular plate portion 25 of the double seal 20 is pressed against a region along the radial direction on the bottom surface of the recess 10 and plays a role of preventing the abradable seal 20 from coming off.

  The retaining ring 30 is, for example, an annular plate. The material of the retaining ring 30 is preferably a metal material, but is preferably made of the same material as the compressor housing 4 in consideration of the coefficient of thermal expansion.

  Next, the form and procedure for attaching the abradable seal 20 to the recess 10 will be described with reference to FIG.

  First, the annular convex part 23 of the cylindrical part 21 of the abradable seal 20 is inserted into the annular concave part 11 of the recess 10 from the axial direction as shown by the arrow 51 in FIG. In this state, the fitted state between the region excluding the ring-shaped convex portion 23 in the cylindrical portion 21 of the abradable seal 20 and the region along the axial direction on the bottom surface of the recess 10 is set to be just fit. .

  Then, in the final process of the press-fitting, the radial direction of the flare portion 22 with the retaining ring 30 fitted in the step portion 24 of the flare portion 22 of the abradable seal 20 as shown by the arrow 52 in FIG. The outer diameter side of the region along the radial direction of the depression 10 is formed by pressing the outer portion against the region along the radial direction on the bottom surface of the depression 10 and the outer circumferential surface of the annular plate portion 25 of the flare 22 and the outer circumferential surface of the retaining ring 30. Fit into the inner peripheral surface 13.

  Since the retaining ring 30 is press-fitted into the outer diameter side inner peripheral surface 13 of the recess 10, the retaining ring 30 prevents the radially outward portion of the flare portion 22 of the abradable seal 20 from coming off. Become.

  By the way, in this embodiment, both axial ends of the abradable seal 20 and the inner surface of the intake passage 4a of the compressor housing 4 are flush with each other so that no step is formed in the seam.

  Therefore, first, in a state where the abradable seal 20 is fitted in the recess 10, the inner peripheral surface of the end portion of the cylindrical portion 21 of the abradable seal 20 (the surface exposed to the intake passage 4 a) and the intake passage of the compressor housing 4. The thickness dimension (dimension along the radial direction) of the cylindrical portion 21 is set as appropriate so that the inner surface of 4a is flush with the plane along the axial direction.

  Further, in the state where the abradable seal 20 is fitted in the recess 10, the outer surface (exposed to the intake passage 4 a) of the portion excluding the annular plate portion 25 in the radially outward portion of the flare portion 22 of the abradable seal 20. Surface), the outer surface of the retaining ring 30 (the surface exposed to the intake passage 4a), and the thickness of the retaining ring 30 so that the surface along the radial direction on the inner surface of the intake passage 4a of the compressor housing 4 is flush with each other. Dimensions (dimensions along the axial direction), thickness dimensions (dimensions along the axial direction) of the annular plate portion 25, and thickness dimensions (dimensions along the axial direction) of the portion excluding the annular plate portion 25 in the radially outward portion of the flare portion 22 ) Is set as appropriate. Alternatively, the retaining ring 30 is press-fitted to the position where the outer surface of the retaining ring 30 (the surface exposed to the intake passage 4a) and the inner surface of the intake passage 4a of the compressor housing 4 are flush with each other. Try to match. In that case, for example, even if the thickness dimension (the dimension along the axial direction) of the annular plate portion 25 is set to be slightly larger, the retaining ring 30 can be fitted by fitting the retaining ring 30 into the above-mentioned flush state. Thus, the annular plate portion 25 can be elastically compressed in the thickness direction.

  As described above, in the embodiment to which the present invention is applied, in summary, by pressing the two axially opposite ends of the abradable seal 20 into the recess 10 in the inner surface of the intake passage 4a of the compressor housing 4, The double seal 20 is fixed to the recess 10.

  This makes it possible to eliminate axial and radial play of the abradable seal 20 with respect to the recess 10. Moreover, since the press-fitting width of both of the press-fitting parts can be smaller than the conventional example according to Patent Document 1, even if the press-fit tightening margin is set larger than that of the conventional example according to Patent Document 1, The abradable seal 20 can be assembled relatively easily, which is advantageous in increasing the production efficiency of the supercharger.

  Furthermore, since play in the axial direction and the radial direction of the abradable seal 20 can be eliminated, it is possible to suppress or prevent the abradable seal 20 from undergoing creep deformation. This makes it easy to design and manage the initial scraping amount of the abradable seal 20 by the compressor impeller 2, so that the clearance between the abradable seal 20 and the blade 2a of the compressor impeller 2 can be set accurately. Become. In particular, in this embodiment, the annular concave portion 11 and the ring-shaped convex portion 23 are press-fitted and the press-fitted portion is continuous in the circumferential direction, so that the pressure due to the press-fitting can be dispersed in the circumferential direction. Yes, it can be said that the effect of suppressing the creep deformation of the abradable seal 20 is high.

  Moreover, in this embodiment, the inner peripheral surface of the cylindrical portion 21 of the abradable seal 20 and the inner surface of the intake passage 4a of the compressor housing 4 are flush with each other so that no step is formed. The outer surface (surface exposed to the intake passage 4a) of the portion excluding the annular plate portion 25 in the radially outward portion of the flare portion 22, the outer surface of the retaining ring 30 (surface exposed to the intake passage 4a), and the compressor housing 4 Since the inner surface of the intake passage 4a is flush with the surface along the radial direction so as not to create a step, air flow resistance in the intake passage 4a of the compressor housing 4 is reduced, and the air It is advantageous for increasing the inhalation efficiency.

  In addition, this invention is not limited only to embodiment mentioned above, All the deformation | transformation and application included in the range equivalent to the claim and the said range are possible. Examples are given below.

  (1) Another embodiment of the present invention will be described with reference to FIGS. In this embodiment, a circumferential groove 15 that is recessed in the axial direction is provided on the maximum outer diameter side of the region along the radial direction on the bottom surface of the recess 10, and the elastic ring 40 is fitted into the circumferential groove 15 in a compressed state. . The elastic ring 40 can be, for example, an O-ring.

  In such a configuration, since the elastic ring 40 seals the mating surface between the abradable seal 20 and the recess 10, the air sucked into the inlet side of the intake channel is passed from the mating surface to the intake channel. It becomes possible to prevent the phenomenon of leaking to the outlet side, which is advantageous for enhancing the intake compression action, for example.

  In addition, since the compression amount in the axial direction of the elastic ring 40 can be adjusted, the fitting state between the maximum outer diameter side of the flared portion 22 of the abradable seal 20 and the recess 10 is appropriately adjusted. It becomes possible. This will be specifically described.

  In the unlikely event, the manufacturing tolerance of the thickness dimension in the radially outward portion of the flare portion 22 of the abradable seal 20 is minimized, and the manufacturing tolerance of the depth dimension of the region along the radial direction in the recess 10 is maximized. In some cases, if the elastic ring 40 is not used, the following situation may occur.

  For example, as shown in FIG. 7, the retaining ring 30 is attached to the recess 10 so that the outer surface of the retaining ring 30 and the inner surface of the intake passage 4 a are substantially flush with each other. It is considered that a gap may be formed between the region along the radial direction and the radially outward portion of the flared portion 22 of the abradable seal 20.

  When the elastic ring 40 described above is used in such a situation, the amount of compression of the elastic ring 40 in the axial direction becomes small and the gap can be filled, so that the sealing performance of the fitting surface is improved. Is possible.

  As described above, when the elastic ring 40 is used, it is advantageous in securing the preferable mounting state by absorbing the dimensional error as described above.

  (2) In the supercharger illustrated in the above embodiment, the portion not directly related to the characteristic configuration of the present invention is not particularly limited.

1 Turbine shaft
2 Compressor impeller
3 Bearing housing
3a Bearing housing side hole
4 Compressor housing
4a Compressor housing intake passage
10 depression
11 Recessed annular recess
12 Dimples
13 Outer diameter side inner peripheral surface of the region along the radial direction of the recess
20 Abradable seal
21 Cylindrical part of abradable seal
22 Flare part of abradable seal
23 Ring-shaped convex part of abradable seal
24 Abradable seal step
25 Annular plate part of abradable seal
30 retaining ring

Claims (5)

On the inner surface of the intake passage of the compressor housing of the turbocharger, a recess that is fitted with an abradable seal having a shape following the round corner region is provided in the round corner region facing the blade of the compressor impeller.
The abradable seal has a shape in which a flare portion is integrally provided on one end side in the axial direction of the cylindrical portion,
In this abradable seal, the other end in the axial direction of the cylindrical portion is press-fitted into the inner side of the region along the axial direction of the recess, and the maximum outer diameter side of the flare portion is inserted into the recess by a retaining ring. An abradable seal fixing structure for a supercharger, wherein the abradable seal fixing structure is fixed to the recess by press-fitting to an inner peripheral surface of an outer diameter side in a region along the radial direction. The abradable seal fixing structure for a turbocharger according to claim 1,
A recess recessed in the axial direction is provided on the outer diameter side of the inner end of the region along the axial direction of the recess, and the other end in the axial direction of the cylindrical portion of the abradable seal is press-fitted into the recess from the axial direction. An abradable seal fixing structure for a turbocharger, wherein a convex portion to be fitted is provided. The abradable seal fixing structure for a turbocharger according to claim 1 or 2,
A step portion is provided at an outer corner portion of the maximum outer diameter portion of the flare portion of the abradable seal,
The retaining ring is press-fitted to the outer peripheral side inner peripheral surface of the region along the radial direction of the recess in a state where the retaining ring is externally fitted to the stepped portion of the abradable seal. An abradable seal fixing structure for a supercharger, wherein a thin annular plate portion existing in the back of the portion is pressed against a region along the radial direction on the bottom surface of the recess. In the supercharger abradable seal fixing structure according to any one of claims 1 to 3,
On the outer end side of the region along the radial direction on the bottom surface of the depression, a circumferential groove recessed in the axial direction is provided, and an elastic ring is fitted into the circumferential groove in a compressed state. Abradable seal fixing structure of the feeder. The abradable seal fixing structure for a supercharger according to any one of claims 1 to 4,
The inner peripheral surface of the end of the cylindrical portion of the abradable seal and the region along the axial direction of the inner surface of the intake passage are flush with each other,
In addition, an abrader for a turbocharger characterized in that a radially outward portion of a flare portion of the abradable seal, a retaining ring, and a region along the radial direction of the inner surface of the intake passage are flush with each other. Double seal fixing structure.

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