JP2009197772A - Thrust bearing device of exhaust gas turbocharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thrust bearing device of an exhaust gas turbocharger which can reduce the occurrence of biased contact in a joint between a thrust collar on a compressor side and a thrust collar on a turbine side and a thrust bearing on the radius direction surface, and can prevent reduction in the service life of the thrust bearing caused by one-side contact. <P>SOLUTION: A low-rigidity formation part is provided to either of the thrust collar on the compressor side and the thrust collar on the turbine side or both of the thrust bearing device of the exhaust gas turbocharger, and the low-rigidity formation part has lower rigidity on the radius direction surface than other parts. At the action of a thrust load, the thrust collar on the compressor side and the thrust collar on the turbine side are locally deformed by the low-rigidity formation part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exhaust turbocharger configured to support a thrust load acting between an exhaust turbine and a compressor of an exhaust turbocharger driven by exhaust gas discharged from an exhaust manifold of an engine by a thrust bearing. The present invention relates to a thrust bearing device for a supercharger.

FIG. 6 is a sectional view in the axial direction of a main part of a general exhaust turbocharger. In FIG. 6, 1 is an exhaust turbine, 2 is a compressor, and the exhaust turbine 1 and the compressor 2 are integrally coupled by a turbine shaft 3. The turbine shaft 3 is supported on the bearing housing 3 by journal bearings 4 and 2 at two locations from the center.
In the exhaust turbocharger, a thrust load S, which is the difference between the axial force of the exhaust turbine 1 and the axial force of the compressor 2, is applied to the turbine shaft 3 on the right side (in the direction of the exhaust turbine 1). Acts towards.

The thrust load S is received by a compressor-side thrust collar 5 having an inner periphery fixed to the turbine shaft 3 and a turbine-side thrust collar 6 having an inner periphery fixed to the turbine shaft 3, and the thrust load S is The bearing is supported by a thrust bearing 7 sandwiched between two thrust collars 5 and 6 and having an outer periphery fixed to the bearing housing 3.
The thrust load S is supported by the bearing housing 3 on the radial surface of the compressor side thrust collar 5 and the thrust bearing 7 and on the radial surface of the turbine side thrust collar 6 and the thrust bearing 7. Yes. 100a is the center of the supercharger.

In Patent Document 1 (JP-A-8-502116), the bearing includes a bearing pad that can be deformed and deformed in any direction (6 degrees of freedom), and the bearing pad can be freely adjusted by fluid film pressure. The flexure and thrust bearings are uniformly formed in a tapered state.
Japanese translation of PCT publication No. 8-502116

  As the thrust bearing 7 of such an exhaust turbocharger, a tapered land type bearing is usually adopted. On the other hand, the use environment of the exhaust turbocharger requires the adoption of DPF (diesel, particulate, filter) due to exhaust gas regulations. Along with this, the outlet pressure of the exhaust turbine 1 increases, the balance of pressure changes, and the thrust load S tends to increase. As a result, the load applied to the thrust bearing 7 increases and the life of the thrust bearing 7 decreases. Tend to.

When the life of the thrust bearing 7 is reduced due to an increase in the load applied to the thrust bearing 7, a thrust load S as shown in FIG. 7 is applied to the radial surface 5 s between the compressor side thrust collar 5 and the thrust bearing 7.
However, when the radial surface 5s is not coincident between the compressor-side thrust collar 5 and the thrust bearing 7, the radial surface 5s receives the thrust load S when the radial portion 5s does not coincide with the X portion. Part X is caused between the compressor side thrust collar 5 and the thrust bearing 7 in the X part, and the occurrence of burnout is observed in the X part of the part.

  In view of the problems of the prior art, the present invention reduces the occurrence of contact per piece at the joint portion of the radial surface between the turbine side thrust collar and the compressor side thrust collar and the thrust bearing, and An object of the present invention is to provide a thrust bearing device for an exhaust turbocharger that prevents a reduction in service life.

The present invention achieves such an object, and a thrust load acting between an exhaust turbine and a compressor of an exhaust turbocharger and a compressor side thrust collar and a turbine side thrust collar each having an inner periphery fixed to a turbine shaft. The thrust bearing is supported by a thrust bearing sandwiched between the two thrust collars and fixed at the outer periphery, and the thrust bearing slides between the compressor-side thrust collar and the turbine-side thrust collar on a radial surface. In a thrust bearing device of an exhaust turbocharger configured to contact and support the thrust load,
One or both of the compressor-side thrust collar and the turbine-side thrust collar is provided with a low-rigidity forming portion that is lower in rigidity than the other portions in the radial direction surface, and the compressor-side thrust collar is activated during the operation of the thrust load. And the turbine-side thrust collar is configured to be locally deformed by the low-rigidity forming portion (claim 1).

Specifically, the invention is configured as follows.
(1) The low-rigidity forming portion is provided with a slit having a certain depth in an outer peripheral portion of one or both of the compressor-side thrust collar and the turbine-side thrust collar.
Here, the slit is
a) The slit is formed in a belt-like groove continuous along the circumferential direction of the exhaust turbocharger. Or
b) The slit is constituted by a groove provided in a direction perpendicular to the radial surface along a plurality of locations in the circumferential direction of the exhaust turbocharger.

(2) The low-rigidity forming portion has a thickness along the radial surface of one or both of the compressor-side thrust collar and the turbine-side thrust collar that decreases in a plurality of steps in order from the inner peripheral side. It is comprised so that the thickness of an outer peripheral part may become the minimum (Claim 5).
(3) The low-rigidity forming portion is configured such that the thickness along the radial surface of one or both of the compressor-side thrust collar and the turbine-side thrust collar decreases linearly from the inner peripheral side, and the outer peripheral portion Is configured to be minimal.
(4) The low-rigidity forming portion has a small radius at one or both of the compressor-side thrust collar and the turbine-side thrust collar and a joint portion between the compressor-side thrust collar and the turbine-side thrust collar and the turbine shaft. A circular notch is provided (claim 7).

According to the present invention, one or both of the compressor-side thrust collar and the turbine-side thrust collar is provided with the low-rigidity forming portion having a rigidity lower than that of the other portion in the radial direction surface. Since the thrust collar and the turbine side thrust collar are configured to be locally deformed by the low rigidity forming portion (Claim 1),
When the thrust load is activated, even if the thrust collar and the thrust bearing do not coincide with each other in the radial direction, the thrust load first causes local deformation of the low-rigidity forming portion with low rigidity. As a result of such deformation, the pressure receiving area with respect to the thrust load is increased, and the load capacity to the thrust load is increased, thereby extending the bearing life.
Further, as described above, by increasing the pressure receiving area with respect to the thrust load, the area of the piece contact portion is increased and wear can be reduced.

In addition, the low-rigidity forming portion is provided with a slit having a certain depth on the outer peripheral portion of one or both of the compressor-side thrust collar and the turbine-side thrust collar (Claim 2). Is formed in a continuous belt-like groove along the circumferential direction of the exhaust turbocharger (Claim 3), or the slits are formed along a plurality of locations in the circumferential direction of the exhaust turbocharger. If the groove is provided in a direction perpendicular to the radial surface (Claim 4),
Even if the radial surfaces of the thrust collar and the thrust bearing do not coincide with each other and the one-side contact occurs, the thrust load first causes local deformation of the slit forming portion having a small rigidity. The pressure receiving area is increased, and the load capacity to the thrust load is increased.

Further, the low-rigidity forming portion is formed on one or both of the compressor-side thrust collar and the turbine-side thrust collar, and the thickness along the radial direction surface is gradually reduced from the inner peripheral side into a plurality of steps, and the outer peripheral portion If configured to minimize the thickness (Claim 5),
Even if the radial surfaces of the thrust collar and the thrust bearing do not match and contact with each other occurs, the tip portion of the thrust collar with low rigidity is first locally deformed by the thrust load. However, the flexibility is increased, and as a result, the pressure receiving area with respect to the thrust load is increased, and the load capacity to the thrust load is increased.

In addition, the thickness along the radial surface of the low-rigidity forming portion on one or both of the compressor-side thrust collar and the turbine-side thrust collar is linearly reduced from the inner peripheral side, and the thickness of the outer peripheral portion is reduced. (Claim 6),
Even if the radial surfaces of the thrust collar and the thrust bearing do not match and contact with each other occurs, the thrust load first causes local deformation of the tip of the thrust collar with low rigidity, and then the thick base. The portions are deformed in order, and therefore the portion per piece is increased in flexibility. As a result, the pressure receiving area with respect to the thrust load is increased, and the load capacity to the thrust load is increased.

Further, the low-rigidity forming portion is formed in one or both of the compressor-side thrust collar and the turbine-side thrust collar, and a circular shape having a small radius at the joint portion between the compressor-side thrust collar and the turbine-side thrust collar and the turbine shaft. (Claim 7),
When thrust load is activated, even if the thrust collar and the thrust bearing are not aligned in the radial direction, the entire thrust collar will be deformed with a notch with low rigidity as a fulcrum. This portion is deformed with increased flexibility along with the deformation, and as a result, the pressure receiving area for the thrust load is increased, and the load capacity for the thrust load is increased.

  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

FIG. 6 is a sectional view in the axial direction of the main part of an exhaust turbocharger to which the present invention is applied.
In such an exhaust turbocharger, a thrust load S, which is the difference between the axial force of the exhaust turbine 1 and the axial force of the compressor 2, is applied to the turbine shaft 3 toward the right side (the direction of the exhaust turbine 1). Is acting.
The thrust load S is received by the compressor side thrust collar 5 whose inner periphery is firmly fixed to the turbine shaft 3 and the turbine side thrust collar 6 whose inner periphery is firmly fixed to the turbine shaft 3. S is supported by a thrust bearing 7 sandwiched between the two thrust collars 5 and 6 and having an outer periphery fixed to the bearing housing 3.
The thrust load S is supported by the bearing housing 3 on the radial surface of the compressor side thrust collar 5 and the thrust bearing 7 and on the radial surface 5s of the turbine side thrust collar 6 and the thrust bearing 7. ing.
The present invention relates to a thrust bearing device that receives such a thrust load.

FIG. 1 is an enlarged cross-sectional view of a compressor side thrust collar and a vicinity of a contact portion between a turbine side thrust collar and a thrust bearing according to a first embodiment of the present invention.
In FIG. 1, the thrust bearing 7 is configured to support the thrust load S by slidingly contacting the thrust bearing 7, the compressor-side thrust collar 5 and the turbine-side thrust collar 6 with a radial surface 5s. Yes.

The compressor-side thrust collar 5 is provided with a low-rigidity forming portion having a lower rigidity than other portions on the radial surface 5s.
That is, the low-rigidity forming portion is provided with a slit 8 having a certain depth on the outer peripheral portion of the compressor-side thrust collar 5 whose inner periphery is firmly fixed to the turbine shaft 3. The slit 8 is formed by a belt-like groove continuous along the circumferential direction of the exhaust turbocharger.

  As shown by the chain line in FIG. 1, the slit 8 can be provided in one or both of the compressor side thrust collar 5 and the turbine side thrust collar 6.

FIG. 1 is a side view of a compressor side thrust collar 5 according to a second embodiment of the present invention as viewed at right angles to the turbine shaft center.
In the second embodiment, the slits 8 are provided with a plurality of grooves (in this example, 12 grooves) provided in a direction perpendicular to the radial surface 5s along a plurality of locations in the circumferential direction of the exhaust turbocharger. ). 100a is an axial center of the exhaust turbocharger.
In the second embodiment, the slit 8 can be provided in one or both of the compressor side thrust collar 5 and the turbine side thrust collar 6.

According to the first and second embodiments, either one or both of the compressor-side thrust collar 5 and the turbine-side thrust collar 6 has a low-rigidity forming portion that is less rigid than the other portions in the radial surface 5s. That is, the slit 8 is provided, and when the thrust load S is activated, the compressor side thrust collar 5 and the turbine side thrust collar 6 are configured to be locally deformed by the slit 8, that is, the slit 8 having the constant depth is provided. As in the first embodiment, one or both of the compressor-side thrust collar 5 and the turbine-side thrust collar 6 are formed in a belt-like groove continuous in the circumferential direction, or in the second embodiment. Thus, the slit 8 is constituted by grooves provided in a direction perpendicular to the radial surface 5s along a plurality of locations in the circumferential direction.
When the thrust load S is activated, even if the radial surface 5s of the thrust collar 6 and the thrust bearing 7 do not coincide with each other and one-side contact occurs, the thrust load S first causes the locally low slit 8 to be locally deformed. By doing so, the deformation per portion of the piece increases the pressure receiving area with respect to the thrust load S, and the load capacity to the thrust load S increases, thereby extending the bearing life.
Further, as the pressure receiving area with respect to the thrust load S is increased as described above, the area of the piece contact portion is increased and wear can be reduced.

FIG. 3 is a diagram corresponding to FIG. 1 according to a third embodiment of the present invention.
In the third embodiment, the low-rigidity forming portion, the compressor-side thrust collar 5, and the thickness along the radial surface 5s are thinned into a plurality of stepped shapes 5a in order from the inner peripheral side. The stepped thrust collar 5 is configured such that the thickness 5b is minimized.
In the third embodiment, the stepped thrust collar 5 can be provided on either or both of the compressor side thrust collar 5 and the turbine side thrust collar 6.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

  According to the third embodiment, even if the radial surface 5s of the thrust collar 5 and the thrust bearing 7 do not coincide with each other and the one-side contact has occurred, the thrust collar S first has the tip portion 5b of the thrust collar having low rigidity. As a result of local deformation, the portion per piece increases the flexibility, and as a result, the pressure receiving area with respect to the thrust load S is expanded, and the load capacity to the thrust load S is increased.

FIG. 4 is a diagram corresponding to FIG. 1 according to a fourth embodiment of the present invention.
In the fourth embodiment, the compressor-side thrust collar 5 has a thickness along the radial surface 5s that decreases from the inner peripheral side fixed to the turbine shaft 3 to a straight line 5c, and the outer peripheral portion 5d has a thickness 5d. The linear thrust collar 5 is configured to be minimized.
In the fourth embodiment, the linear thrust collar 5 can be provided on either or both of the compressor side thrust collar 5 and the turbine side thrust collar 6.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

  According to the fourth embodiment, even if the radial surface 5s of the thrust collar 5 and the thrust bearing 7 do not coincide with each other and the one-side contact occurs, the tip end portion of the thrust collar having low rigidity is first caused by the thrust load S. 5d is locally deformed, and then the thick base portion is deformed in order, so that the portion per piece is increased in flexibility. As a result, the pressure receiving area for the thrust load S is increased. The load capacity to the thrust load increases.

FIG. 5 is a block diagram corresponding to FIG. 1 according to the fifth embodiment of the present invention.
In the fifth embodiment, the compressor-side thrust collar 5 is formed with a circular notch 5e having a small radius at the joint portion between the compressor-side thrust collar 5 and the turbine shaft 3.
In the fifth embodiment as well, the thrust collar provided with the notch 5e can be provided on one or both of the compressor side thrust collar 5 and the turbine side thrust collar 6.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

  According to the fourth embodiment, when the thrust load S is actuated, even if the radial surface 5s of the thrust collar 5 and the thrust bearing 7 do not coincide with each other and the one-side contact occurs, the cutout portion having a low rigidity is first provided. 5e is used as a fulcrum, and the entire thrust collar 5 is deformed as 5f. Therefore, the portion per piece is deformed with increased flexibility along the deformation 5f, and as a result, the pressure receiving area with respect to the thrust load S is increased. The load capacity to the load S increases.

  According to the present invention, the occurrence of contact per piece at the joint portion of the radial surface of the compressor side thrust collar and the turbine side thrust collar and the thrust bearing is reduced, and the life of the thrust bearing due to the contact is prevented from being reduced. A thrust bearing device for an exhaust turbocharger can be provided.

It is an expanded sectional view of the contact part vicinity of the turbine side thrust collar and turbine side thrust collar and thrust bearing which concern on 1st Example of this invention. It is the side view seen at right angles to the turbine axial center of the turbine side thrust collar which concerns on 2nd Example of this invention. FIG. 6 is a diagram corresponding to FIG. 1 according to a third embodiment of the present invention. FIG. 6 is a diagram corresponding to FIG. 1 according to a fourth embodiment of the present invention. FIG. 10 is a diagram corresponding to FIG. 1 according to a fifth embodiment of the present invention. It is sectional drawing of the axial direction of the principal part of the exhaust gas turbocharger to which this invention is applied. It is a figure corresponding to FIG. 1 which shows a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exhaust turbine 2 Compressor 3 Turbine shaft 5 Compressor side thrust collar 5s Radial surface 5e Notch 6 Turbine side thrust collar 7 Thrust bearing 8 Slit S Thrust load

Claims (7)

The thrust load acting between the exhaust turbine of the exhaust turbocharger and the compressor is sandwiched between the two thrust collars via a turbine side thrust collar and a compressor side thrust collar each having an inner periphery fixed to the turbine shaft. The thrust bearing is supported by a thrust bearing having a fixed outer periphery, and the thrust bearing is supported by sliding the thrust bearing, the turbine-side thrust collar, and the compressor-side thrust collar in a radial plane to support the thrust load. In the thrust turbocharger thrust bearing device configured in
One or both of the turbine-side thrust collar and the compressor-side thrust collar is provided with a low-rigidity forming portion that is lower in rigidity than the other portions in the radial direction surface, and the turbine-side thrust collar is operated during the operation of the thrust load. And a thrust bearing device for an exhaust turbocharger, wherein the compressor side thrust collar is locally deformed by the low rigidity forming portion.   2. The exhaust turbocharger according to claim 1, wherein the low-rigidity forming portion is provided with a slit having a certain depth in an outer peripheral portion of one or both of the turbine-side thrust collar and the compressor-side thrust collar. Thrust bearing device of the machine.   The thrust bearing device for an exhaust turbocharger according to claim 2, wherein the slit is formed in a belt-like groove continuous along a circumferential direction of the exhaust turbocharger.   3. The exhaust turbocharger according to claim 2, wherein the slit is constituted by a groove provided in a direction perpendicular to the radial surface along a plurality of circumferential positions of the exhaust turbocharger. Thrust bearing device.   The low-rigidity forming portion has a thickness along the radial surface of one or both of the turbine-side thrust collar and the compressor-side thrust collar that decreases in a plurality of steps in order from the inner peripheral side. The thrust bearing device for an exhaust turbocharger according to claim 1, wherein the thrust bearing device is configured to have a minimum thickness.   The low-rigidity forming portion has a thickness along the radial surface of one or both of the turbine-side thrust collar and the compressor-side thrust collar that decreases linearly from the inner peripheral side, and the thickness of the outer peripheral portion. The thrust bearing device for an exhaust turbocharger according to claim 1, wherein the thrust bearing device is configured so as to be minimized.   The low-rigidity forming portion has a circular shape with a small radius at one or both of the turbine-side thrust collar and the compressor-side thrust collar, and at the joint between the turbine-side thrust collar and the compressor-side thrust collar and the turbine shaft. The thrust bearing device for an exhaust turbocharger according to claim 1, further comprising a notch.

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