JP2019100517A - Thrust bearing - Google Patents

Abstract

To provide a thrust bearing which enables easy processing of a bearing side oil passage and a reduction of a diameter.SOLUTION: A thrust bearing 4 includes: a slide surface 41 supporting an axial thrust load acting on a rotary shaft 50 through an oil film; and a bearing side oil passage 70 in which lubrication oil O for oil film formation flows. The bearing side oil passage 70 extends in directions including at least a radial direction and has a bearing side first section 700 opening on an outer peripheral surface 42 of the thrust bearing 4.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a thrust bearing that supports a thrust load acting on a rotating shaft.

  As shown in Patent Document 1, the rotating shaft of the turbocharger is rotatably supported by a thrust bearing via an oil film. The thrust bearing is provided with a sliding surface and an oil passage (bearing side oil passage). The sliding surface is in sliding contact with the projecting portion of the compressor wheel via an oil film. The lubricating oil for forming the oil film is supplied from the oil passage (housing side oil passage) of the bearing housing to the sliding surface via the bearing side oil passage. The inlet of the bearing side oil passage opens at the axial end face of the thrust bearing. On the other hand, the outlet of the bearing side oil passage opens at the inner peripheral surface of the thrust bearing. That is, the bearing side oil passage extends in an oblique direction (direction intersecting with the axial direction and the radial direction) in the axial cross section of the turbocharger.

Unexamined-Japanese-Patent No. 2012-31810

  By reducing the diameter of the thrust bearing, it is possible to reduce the manufacturing cost of the thrust bearing (for example, the material cost of the thrust bearing, and the processing cost if the surface treatment is required). However, as the diameter of the thrust bearing is reduced, the area of the axial end face of the thrust bearing is reduced accordingly. Therefore, it is necessary to reduce the inclination angle of the bearing-side oil passage (the inclination angle of the bearing-side oil passage with respect to the axial direction of the rotating shaft). Therefore, processing of the bearing side oil passage becomes difficult.

  Therefore, an object of the present invention is to provide a thrust bearing in which the processing of the bearing side oil passage is easy and the diameter can be reduced.

  In order to solve the above problems, in the thrust bearing according to the present invention, a sliding surface for supporting an axial thrust load acting on a rotary shaft through an oil film, and a bearing-side oil passage in which lubricating oil for forming the oil film flows. And the bearing-side oil passage has a bearing-side first section extending in a direction including at least a radial direction and opening on an outer peripheral surface of the thrust bearing.

  The bearing-side first section of the bearing-side oil passage of the thrust bearing according to the present invention is open at the outer peripheral surface. For this reason, compared with the case where the bearing side oil passage opens at the axial end face of the thrust bearing, it becomes easy to extend the bearing side first section in the radial direction. Therefore, installation of the bearing side oil path to the thrust bearing, that is, machining of the bearing side oil path is simplified. Further, the diameter of the thrust bearing can be reduced.

FIG. 1 is an axial sectional view of a turbocharger provided with the thrust bearing of the first embodiment. FIG. 2A is an enlarged view in a frame IIA of FIG. FIG. 2B is a cross-sectional view taken along line IIB-IIB of FIG. FIG. 3A is an axial sectional view of a thrust bearing arrangement portion. FIG. 3 (B) is a cross-sectional view taken along line IIIB-IIIB in FIG. 3 (A). FIG. 4 is a front view of the same thrust bearing. FIG. 5A is a radial sectional view (part 1) of a housing assembly provided with the same thrust bearing. FIG. 5 (B) is a radial sectional view (part 2) of the same housing assembly. FIG. 6 is a radial cross-sectional view of a housing assembly including the thrust bearing of the second embodiment. FIG. 7 is a radial cross-sectional view of a housing assembly including the thrust bearing of the third embodiment. FIG. 8 is a radial cross-sectional view of a housing assembly comprising the thrust bearing of the fourth embodiment. FIG. 9 is a radial cross-sectional view of a housing assembly comprising the thrust bearing of the fifth embodiment. FIG. 10 is a radial cross-sectional view of a housing assembly comprising the thrust bearing of the sixth embodiment.

  Hereinafter, an embodiment of a thrust bearing of the present invention will be described.

First Embodiment
[Configuration of turbocharger]
First, the configuration of a turbocharger provided with the thrust bearing of the present embodiment will be described. In the following drawings, the front-rear direction corresponds to the "axial direction" of the present invention. FIG. 1 shows an axial sectional view of a turbocharger provided with the thrust bearing of the present embodiment. FIG. 2A shows an enlarged view in the frame IIA of FIG. FIG. 2 (B) shows a cross-sectional view in the direction of IIB-IIB of FIG. 2 (A). In FIG. 2 (B), the retainer is omitted. FIG. 3A shows an axial sectional view of the thrust bearing arrangement portion. FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. 3A (a front view of the thrust bearing arrangement portion). Note that FIG. 3 (A) corresponds to FIG. 2 (A), and FIG. 3 (B) corresponds to FIG. 2 (B). FIG. 4 shows a front view of the same thrust bearing.

  As shown in FIGS. 1 to 4, the turbocharger 1 includes a journal bearing 3, a thrust bearing 4, a rotating portion 5, a retainer 60, a deflector 61, an oil passage 7, a bearing housing 90, and a compressor housing. 91 and a turbine housing 92. The bearing housing 90 is included in the concept of the "other member" of the present invention. Further, the housing assembly 2 of the present embodiment includes a thrust bearing 4, a bearing housing 90, and an oil passage 7.

  Inside the bearing housing 90, a thrust bearing arrangement portion 900, a journal bearing arrangement portion 904, and housing side oil passages 905a and 905b are formed. The lubricating oil O is flowing in the housing side oil passages 905a and 905b. The journal bearing arrangement portion 904 has a hole shape centered on the axial center A of the rotating shaft 50. The journal bearing arrangement portion 904 extends in the front-rear direction. The thrust bearing arrangement portion 900 is continuous with the front side of the journal bearing arrangement portion 904. The thrust bearing arrangement portion 900 has a stepped hole shape centering on the axial center A of the rotating shaft 50. The thrust bearing arrangement portion 900 extends in the front-rear direction.

  The journal bearing 3 has a cylindrical shape. The journal bearing 3 is disposed in the journal bearing arrangement portion 904. The thrust bearing 4 is disposed in the thrust bearing arrangement portion 900. The compressor housing 91 is disposed on the front side of the bearing housing 90. The turbine housing 92 is disposed on the rear side of the bearing housing 90.

  The rotating unit 5 is rotatable with respect to the bearing housing 90. The rotating unit 5 includes a rotating shaft 50, a compressor impeller 51, a turbine impeller 52, a thrust collar 53, and a color turbo seal ring 54.

  The rotating shaft 50 penetrates the bearing housing 90 in the front-rear direction. The rotation shaft 50 has a stepped cylindrical shape centered on the axis A. The rotating shaft 50 is rotatably supported by the journal bearing 3 from the radially outer side. The rotating shaft 50 is rotatably supported by the thrust bearing 4 from the front-rear direction via the thrust collar 53. The compressor impeller 51 is attached to the front end of the rotating shaft 50. The turbine impeller 52 is continuous with the rear end of the rotating shaft 50. That is, the rotating shaft 50 connects the compressor impeller 51 and the turbine impeller 52.

  The thrust collar 53 is fixed to the outer peripheral surface of the rotating shaft 50. The thrust collar 53 is rotatably supported by the thrust bearing 4 from the front-rear direction. The color turbo seal ring 54 is disposed on the front side of the thrust collar 53.

  The retainer 60 and the deflector 61 are disposed in the thrust bearing arrangement portion 900 together with the thrust bearing 4 described above. The retainer 60 includes a bottom wall 600 and a peripheral wall 601. A through hole 600 a is formed at the radial center of the bottom wall 600. A color turbo seal ring 54 is rotatably disposed radially inward of the through hole 600a. A ring seal 600 b is disposed between the through hole 600 a and the color turbo seal ring 54. A through hole 601 a is formed in the lower portion of the peripheral wall portion 601.

  The deflector 61 covers the opening edge of the peripheral wall portion 601 from the rear side. The deflector 61 is formed with a through hole 610 and a discharge hole 611. A color turbo seal ring 54 is rotatably disposed radially inside the through hole 610. The discharge hole 611 is disposed below the through hole 610.

[Configuration around the thrust bearing arrangement portion]
Next, the configuration in the vicinity of the thrust bearing arrangement portion will be described in detail. The retainer 60, the deflector 61, the thrust collar 53, the collar turbo seal ring 54, the thrust bearing 4, and part of the rotating shaft 50 are disposed radially inside the thrust bearing arrangement portion 900.

  The thrust collar 53 includes a collar body 530 and a flange 531. The collar main body 530 includes a cylindrical portion 530a and a flange portion 530b. The flange portion 530 b protrudes outward in the radial direction from the rear end of the outer peripheral surface of the cylindrical portion 530 a. The flange 531 is disposed on the front side of the cylindrical portion 530a. The flange 531 has the same diameter as the flange 530b.

  The thrust bearing 4 is disposed radially outside the thrust collar 53. The thrust bearing 4 has a square shape in which four corners are round-chamfered when viewed from the front side (axial direction). The thrust bearing 4 includes a through hole 40, a pair of sliding surfaces 41, and an outer peripheral surface 42. The through hole 40 is disposed radially outside the cylindrical portion 530 a. The pair of sliding surfaces 41 is disposed on both the front and rear surfaces of the thrust bearing 4. The front sliding surface 41 is in sliding contact with the rear surface of the flange 531, and the rear sliding surface 41 is in sliding contact with the front surface of the flange portion 530b via an oil film. The pair of sliding surfaces 41 support a thrust load acting on the rotation shaft 50 in the front-rear direction. The sliding surface 41 includes a tapered portion 410 and a land portion 411. The land portion 411 is disposed on the downstream side of the tapered portion 410 (specifically, on the downstream side of the sliding surface 41 in the flow direction of the lubricating oil O as indicated by the arrow Y in FIG. 2B). The outer circumferential surface 42 includes four contact portions 420 and four non-contact portions 421. The contact portions 420 and the non-contact portions 421 are alternately arranged in the circumferential direction. The contact portion 420 has a curved surface (a partial arc having a constant curvature with the axis A of the rotation shaft 50 as the center of curvature when viewed from the front). The non-contact portion 421 has a planar shape (linear shape when viewed from the front side).

  A bearing side oil passage 70 is disposed in the thrust bearing 4. The bearing side oil passage 70 includes a bearing side first section 700 and a bearing side second section 701. The bearing side second section 701 is an oil hole. The bearing side second section 701 extends linearly in the front-rear direction. The bearing side second section 701 penetrates between the pair of front and rear sliding surfaces 41. The bearing-side second section 701 opens at the upstream portion of the tapered portion 410. The bearing side first section 700 is an oil hole. The bearing side first section 700 extends linearly in the radial direction. The inlet of the bearing-side first section 700 is open to the noncontact portion 421 of the outer circumferential surface 42 of the thrust bearing 4. On the other hand, the outlet of the bearing-side first section 700 is open at the longitudinal middle portion of the bearing-side second section 701.

  The thrust bearing arrangement portion 900 has a stepped hole shape which gradually reduces in diameter from the front side to the rear side. That is, the thrust bearing arrangement portion 900 includes a large diameter portion 901, an intermediate diameter portion 902, and a small diameter portion 903 from the front side toward the rear side.

  The large diameter portion 901 has a circular shape when viewed from the front side. The large diameter portion 901 includes a large diameter inner circumferential surface 901 a and a large diameter step surface 901 b. An upper portion of an outlet of the housing side oil passage 905a is opened in the large diameter step surface 901b. The large diameter inner circumferential surface 901 a is included in the concept of “the inner circumferential surface of the opposite member” in the present invention. A part of the bottom wall 600 of the retainer 60, the peripheral wall 601 of the retainer 60, the deflector 61, the front portion of the thrust collar 53, the front portion of the thrust bearing 4, and the rotation shaft 50 Some are arranged.

  The medium diameter portion 902 has a circular shape when viewed from the front side. The medium diameter portion 902 is smaller in diameter than the large diameter portion 901. The middle diameter portion 902 includes a middle diameter inner circumferential surface 902 a and a middle diameter step surface 902 b. A lower side portion of an outlet of the housing side oil passage 905a is opened in the middle diameter step surface 902b. The medium-diameter inner peripheral surface 902a is included in the concept of the "inner peripheral surface of the mating member" in the present invention. A portion of the cylindrical portion 530 a of the thrust collar 53, a rear portion of the thrust bearing 4, and a portion of the rotary shaft 50 are disposed radially inward of the middle diameter portion 902.

  The small diameter portion 903 has a circular shape when viewed from the front side. The small diameter portion 903 is smaller in diameter than the middle diameter portion 902. The small diameter portion 903 has a small diameter inner circumferential surface 903a and a small diameter step surface 903b. The flange portion 530 b of the thrust collar 53 and a part of the rotary shaft 50 are disposed radially inward of the small diameter portion 903.

  The outer surface (outer peripheral surface 42, rear surface (axial direction end surface)) of the thrust bearing 4 and the inner surface (large diameter inner peripheral surface 901a, middle diameter inner peripheral surface 902a, small diameter inner peripheral surface 903a of the thrust bearing arrangement portion 900) ), And the gap between the step surface (large-diameter step surface 901b, medium-diameter step surface 902b, small-diameter step surface 903b), that is, the end face in the axial direction) 71 are divided.

  The boundary-side oil passage 71 includes four boundary-side first sections 710 and two boundary-side second sections 711 and 712. As shown in FIG. 2B, as viewed from the front side, the boundary side first section 710 is partitioned between the non-contact portion 421 and the middle diameter inner circumferential surface 902a. As shown in FIG. 2A, when viewed from the right side (radial direction), the boundary side first section 710 is partitioned between the rear surface (axial end surface) of the deflector 61 and the middle diameter step surface 902b. ing. As shown in FIG. 2B, as viewed from the front side, the four boundary side first sections 710 are spaced apart at every central angle (the center is the axial center A) 90 °.

  As shown in FIG. 2B, when viewed from the front side, the boundary side second section 711 is partitioned between the outer peripheral surface 42 and the large diameter inner peripheral surface 901 a. As shown in FIG. 2A, as viewed from the right side (radial direction), the boundary side second section 711 is between the rear end surface (axial direction end surface) of the peripheral wall portion 601 and the large diameter step surface 901b. It is divided. As shown in FIG. 2 (B), when viewed from the front side, the boundary side second section 711 exhibits an endless annular shape. The boundary side second section 711 connects four boundary side first sections 710.

  As shown in FIG. 2 (A), the boundary side second section 712 is an oil groove. The boundary side second section 712 is recessed in the middle diameter step surface 902 b. In other words, the boundary side second section 712 is divided between the rear surface of the thrust bearing 4 and the middle diameter step surface 902 b. As shown in FIG. 2 (B), when viewed from the front side, the boundary side second section 712 exhibits an endless annular shape. The boundary side second section 712 connects the four boundary side first sections 710.

[Oil path]
Next, the configuration of the oil passage of the present embodiment will be described. The oil passage 7 communicates the housing-side oil passage 905a with the pair of front and rear sliding surfaces 41. The oil passage 7 is provided with the above-mentioned bearing side oil passage 70 and the above-mentioned boundary side oil passage 71.

  When the turbocharger 1 is driven, the lubricating oil O flows into the uppermost boundary first section 710 among the four boundary first sections 710 via the housing side oil passage 905a. The lubricating oil O that has flowed into the uppermost boundary-side first section 710 passes through the boundary-side second sections 711 and 712 to the remaining three boundary-side first sections 710. The lubricating oil O that has spread to the four boundary-side first sections 710 passes through the bearing-side first section 700 and the bearing-side second section 701 to a pair of sliding surfaces 41 (specifically, upstream of the taper portion 410 Part) supplied. The supplied lubricating oil O is pressurized when the tapered portion 410 flows, and forms an oil film of a desired load capacity at the land portion 411. The thrust bearing 4 supports a thrust load acting on the rotating shaft 50 by the oil film. The lubricating oil O after the formation of the oil film is discharged to the outside of the bearing housing 90 from the housing side oil passage 905 b and the through hole 601 a.

[Function effect]
Next, the function and effect of the thrust bearing of the present embodiment will be described. As shown in FIG. 2A, FIG. 2B, and FIG. 4, the bearing-side first section 700 of the bearing-side oil passage 70 of the thrust bearing 4 of the present embodiment is open at the outer peripheral surface 42. Therefore, compared with the case where the bearing side oil passage 70 is opened at the rear surface (axial direction end surface) of the thrust bearing 4, the bearing side first section 700 can be easily extended in the radial direction. In other words, the extending direction of the bearing-side first section 700 is less likely to include the longitudinal component. Therefore, installation of the bearing side oil passage 70 with respect to the thrust bearing 4, that is, machining of the bearing side oil passage 70 is simplified.

  Specifically, in the case where the bearing side oil passage 70 is opened obliquely on the rear surface of the thrust bearing 4 (in the direction perpendicular to the longitudinal direction and the radial direction), the processing of the bearing side oil passage 70 is simplified. It is necessary to form a recess (a recess for opening the bearing side oil passage 70) on the rear surface of the thrust bearing 4 in advance. Further, the bottom surface of the recess needs to be flat. In addition, in consideration of the processability of the bearing side oil passage 70, the bottom surface needs to be extended in a direction perpendicular to the extending direction (oblique direction) of the bearing side oil passage 70. However, the operation of forming the recess is complicated. In this respect, the bearing-side first section 700 of the bearing-side oil passage 70 of the thrust bearing 4 of the present embodiment is open to the outer circumferential surface 42. For this reason, it is not necessary to form a recess in the rear surface of the thrust bearing 4 in a daring manner. Therefore, installation of the bearing side oil passage 70 with respect to the thrust bearing 4, that is, machining of the bearing side oil passage 70 is simplified.

  Further, when the bearing side first section 700 is extended in the radial direction, the length of the bearing side first section 700 can be shortened accordingly. Therefore, the diameter of the thrust bearing 4 can be reduced. Therefore, the bearing housing 90 can be reduced in diameter.

  As shown in FIGS. 2A and 2B, the bearing-side first section 700 is open at the non-contact portion 421. Further, the bearing side first section 700 is in communication with the boundary side first section 710. Therefore, the lubricating oil O can be stored in the boundary side first section 710 when the engine is stopped. Therefore, the lubricating oil O can be quickly supplied to the sliding surface 41 when the engine is started.

  As shown in FIG. 2A, FIG. 2B, and FIG. 4, a single non-contact portion 421 has a single first bearing-side first section 700 open. That is, the bearing-side first section 700, the bearing-side second section 701, and the non-contact portion 421 are arranged individually for each of the four tapered portions 410. Therefore, the lubricating oil O can be reliably supplied to each of the four taper portions 410.

  As shown in FIGS. 2A and 2B, according to the housing assembly 2 of the present embodiment, the boundary side oil passage 71 resulting from the difference in shape between the thrust bearing 4 and the thrust bearing arrangement portion 900 is It can be used as at least a part of the oil passage 7. Accordingly, the configuration (shape, number of arrangements, etc.) of the bearing side oil passage 70 disposed in the thrust bearing 4 can be simplified. Therefore, the diameter of the thrust bearing 4 can be reduced.

  Specifically, the bearing-side first section 700 is open to the non-contact portion 421. Further, the bearing side first section 700 is in communication with the boundary side first section 710. Thus, the boundary side first section 710 can be used as part of the oil passage 7. Further, the bearing-side oil passage 70 can be constituted by a bearing-side first section 700 extending linearly in the radial direction and a bearing-side second section 701 extending linearly in the front-rear direction. Therefore, the diameter of the thrust bearing 4 can be reduced.

  As shown in FIGS. 2A and 2B, the bearing-side second section 701 is in communication with the bearing-side first section 700 and extends in a direction including at least the front-rear direction. Further, the bearing side second section 701 is open to the sliding surface 41. For this reason, the lubricating oil O can be supplied to the sliding surface 41 without passing through the through hole 40.

  As shown in FIGS. 2A and 2B, the non-contact portion 421 has a planar shape. In addition, the non-contact portion 421 extends in the direction orthogonal to the radial direction. On the other hand, the bearing side first section 700 extends in the radial direction. Therefore, the bearing-side first section 700 can be easily disposed in the non-contact portion 421.

  As shown in FIGS. 2 (A) and 2 (B), the boundary side second section 711 is disposed radially outside the thrust bearing 4. The boundary side second section 711 communicates between the four boundary side first sections 710. Therefore, the lubricating oil O can be distributed from the uppermost boundary side first section 710 to the remaining three boundary side first sections 710. Similarly, the boundary side second section 712 is disposed on the rear side of the thrust bearing 4. The boundary side second section 712 communicates between the four boundary side first sections 710. Therefore, the lubricating oil O can be distributed from the uppermost boundary side first section 710 to the remaining three boundary side first sections 710.

  As shown in FIGS. 2A and 2B, the contact portion 420 is in surface contact with the middle diameter inner circumferential surface 902a. Therefore, the radial position of the thrust bearing 4 with respect to the thrust bearing arrangement portion 900 can be determined. Further, the non-contact portion 421 is separated from the middle diameter inner circumferential surface 902 a. Therefore, the boundary side first section 710 can be divided.

  As shown in FIGS. 2A and 2B, the thrust bearing 4 is sandwiched by the deflector 61 on the front side and the medium-diameter step surface 902b on the rear side. Therefore, the longitudinal position (axial position) of the thrust bearing 4 can be determined.

  The circumferential position of the thrust bearing 4 is not determined. For this reason, the thrust bearing 4 is rotatable. However, even if the thrust bearing 4 is carried along with the thrust collar 53, the lubricating oil O is supplied to the bearing-side oil passage 70 by the boundary side second sections 711 and 712 extending in the circumferential direction. it can. Therefore, an oil film can be formed on the sliding surface 41. Thus, according to the thrust bearing 4 of the present embodiment, fasteners (bolts, screws, etc.) for positioning in the circumferential direction are unnecessary (of course, the circumferential position of the thrust bearing 4 may be determined).

  FIG. 5 (A) shows a radial sectional view (part 1) of a housing assembly provided with the thrust bearing of the present embodiment. FIG. 5 (B) shows a radial sectional view (part 2) of the same housing assembly. 5 (A) and 5 (B) correspond to FIG. 2 (B).

  As shown in FIG. 2B, the circumferential width B of the boundary side first section 710 is wider than the circumferential width C of the outlet of the housing side oil passage 905a. Therefore, as shown in FIG. 5A, the boundary side first section 710 (that is, the thrust bearing 4) is attached at an inclination of the central angle + θ with respect to the housing side oil passage 905a (that is, the bearing housing 90). However, the housing side oil passage 905a and the boundary side first section 710 can be reliably communicated with each other.

  Similarly, as shown in FIG. 5B, even if the boundary side first section 710 is attached at an inclination of the central angle -θ with respect to the housing side oil passage 905a, the housing side oil passage 905a can be reliably provided. And the boundary side first section 710 can be communicated.

  As described above, according to the housing assembly 2 of the present embodiment, even if the mounting accuracy (positioning accuracy) of the thrust bearing 4 with respect to the bearing housing 90 in the circumferential direction is poor, lubricating oil is reliably applied to the sliding surface 41 Can be supplied. Therefore, the mounting operation of the thrust bearing 4 to the bearing housing 90 is simplified.

Second Embodiment
The difference between the thrust bearing of this embodiment and the thrust bearing of the first embodiment is that lubricating oil is supplied to the sliding surface via the inner circumferential surface of the thrust bearing. Here, only the differences will be described.

  FIG. 6 shows a radial sectional view of a housing assembly provided with the thrust bearing of the present embodiment. Note that portions corresponding to those in FIG. 2B are denoted by the same reference numerals. As shown in FIG. 6, the outer circumferential surface 42 of the thrust bearing 4 is provided with a single contact portion 420 and a single non-contact portion 421. The bearing side oil passage 70 is provided with a single bearing side first section 700. The bearing side first section 700 extends linearly in the radial direction. The inlet (radial outer end) of the bearing-side first section 700 is open to the noncontact portion 421. The outlet (radially inner end) of the bearing-side first section 700 is open to the through hole 40, that is, the inner peripheral surface of the thrust bearing 4. Lubricating oil is supplied from the housing-side oil passage 905a to the sliding surface 41 via the boundary-side first section 710, the bearing-side first section 700, and the gap between the through hole 40 and the cylindrical portion 530a. .

  The thrust bearing of the present embodiment and the thrust bearing of the first embodiment have the same effects as those of the parts having the same configuration. According to the thrust bearing 4 of the present embodiment, the bearing-side second section 701 shown in FIG. 2B is unnecessary (as a matter of course, the bearing-side second section 701 may be disposed). Therefore, the configuration of the bearing side oil passage 70 is simplified. Moreover, according to the thrust bearing 4 of the present embodiment, the boundary side second section 712 shown in FIG. 2B is unnecessary (as a matter of course, the boundary side second section 712 may be arranged). Therefore, the configuration of the boundary side oil passage 71 is simplified. Further, according to the thrust bearing 4 of the present embodiment, the arrangement number of the noncontact portion 421, the boundary side first section 710, and the bearing side first section 700 may be single. Therefore, the configuration of the thrust bearing 4 is simplified. In addition, the boundary side second section 711 shown in FIG. 6 may not be disposed. This simplifies the configuration of the boundary side oil passage 71.

Third Embodiment
The difference between the thrust bearing of this embodiment and the thrust bearing of the first embodiment is that lubricating oil is supplied to the sliding surface via the front and rear surfaces (both axial end surfaces) of the thrust bearing. is there. Here, only the differences will be described.

  FIG. 7 shows a radial cross-sectional view of a housing assembly provided with the thrust bearing of the present embodiment. Note that portions corresponding to those in FIG. 2B are denoted by the same reference numerals. As shown in FIG. 7, the bearing side oil passage 70 includes four bearing side first sections 700. The bearing side first section 700 is an oil groove. The bearing-side first section 700 is recessed on the front and rear surfaces of the thrust bearing 4. The bearing side first section 700 extends linearly in the radial direction. The inlet (radial outer end) of the bearing-side first section 700 is open to the noncontact portion 421. The outlet (radially inner end) of the bearing-side first section 700 opens at the upstream end of the tapered portion 410. The lubricating oil is supplied from the housing-side oil passage 905a via the four boundary-side first sections 710 (the lubricating oil is distributed in the entire circumferential direction by the boundary-side second sections 711 and 712) and the four bearing-side first sections 700. Is supplied to the sliding surface 41.

  The thrust bearing of the present embodiment and the thrust bearing of the first embodiment have the same effects as those of the parts having the same configuration. According to the thrust bearing 4 of the present embodiment, the bearing-side second section 701 shown in FIG. 2B is unnecessary (as a matter of course, the bearing-side second section 701 may be disposed). Therefore, the configuration of the bearing side oil passage 70 is simplified. Moreover, according to the thrust bearing 4 of the present embodiment, the bearing-side first section 700 has a groove shape. For this reason, compared with the case where the bearing side first section 700 has a hole shape, the bearing side first section 700 can be easily disposed in the thrust bearing 4.

Fourth Embodiment
The difference between the thrust bearing of the present embodiment and the thrust bearing of the first embodiment is that a plurality of bearing-side first sections are opened in a single noncontact portion. Here, only the differences will be described.

  FIG. 8 shows a radial cross-sectional view of a housing assembly provided with the thrust bearing of the present embodiment. Note that portions corresponding to those in FIG. 2B are denoted by the same reference numerals. As shown in FIG. 8, the outer circumferential surface 42 of the thrust bearing 4 includes two left and right contact portions 420 and two upper and lower non-contact portions 421. The bearing side oil passage 70 includes four bearing side first sections 700 and four bearing side second sections 701. The bearing side first section 700 extends linearly in the vertical direction (direction including the radial direction and the circumferential direction). In the upper non-contact portion 421, the inlets (radial outer ends) of the two bearing side first sections 700 are opened. Similarly, in the lower noncontact portion 421, the inlets of the two bearing side first sections 700 are open. Lubricating oil is divided into two boundary side first sections 710 (the lubricating oil spreads in the entire circumferential direction by boundary side second sections 711 and 712) from the housing side oil passage 905a, four bearing side first sections 700, four The sliding surface 41 is supplied via the two bearing side second sections 701.

  The thrust bearing of the present embodiment and the thrust bearing of the first embodiment have the same effects as those of the parts having the same configuration. According to the thrust bearing 4 of the present embodiment, the plurality of bearing-side first sections 700 are opened in the single non-contact portion 421. Therefore, the number of non-contacting parts 421 in the thrust bearing 4 can be reduced.

Fifth Embodiment
The difference between the thrust bearing of the present embodiment and the thrust bearing of the first embodiment is that the inner diameter inner circumferential surface has a square shape with four corners rounded, as viewed from the front side. In addition, the thrust bearing has a square shape in which the four corners are chamfered as viewed from the front side. Moreover, it is a point in which the bearing side first section is open at the contact portion. Here, only the differences will be described.

  FIG. 9 shows a radial cross-sectional view of a housing assembly provided with the thrust bearing of this embodiment. Note that portions corresponding to those in FIG. 2B are denoted by the same reference numerals. As shown in FIG. 9, the thrust bearing 4 has a square shape (octagonal shape) in which four corners are chamfered as viewed from the front side. That is, the outer circumferential surface 42 of the thrust bearing 4 is provided with four contact portions 420 and four non-contact portions 421. Each of the contact portion 420 and the non-contact portion 421 has a planar shape (linear shape when viewed from the front side). In the contact portion 420, the inlet (radial outer end) of the bearing-side first section 700 is opened.

  The medium-diameter inner circumferential surface 902 a has a square shape with four corners rounded, as viewed from the front side. The contact portion 420 of the thrust bearing 4 is in plane contact with the middle diameter inner circumferential surface 902 a. Four boundary-side second sections 712 are recessed in the middle diameter inner circumferential surface 902a. The boundary side second section 712 is an oil groove. The boundary side second section 712 extends in the direction including the circumferential direction and the radial direction. A pair of boundary first sections 710 is disposed on both longitudinal sides of any single second boundary section 712. The boundary side second section 712 communicates the pair of boundary side first sections 710 with each other. Further, the boundary side second section 712 communicates the pair of boundary side first sections 710 with the bearing side first section 700. The lubricating oil is distributed from the housing-side oil passage 905a to the four boundary-side first sections 710 (the lubricating oil is circumferentially extended by the boundary-side second sections 711, the four boundary-side second sections 712), The sliding surface 41 is supplied via the boundary side second section 712, the four bearing side first sections 700, and the four bearing side second sections 701.

  The thrust bearing of the present embodiment and the thrust bearing of the first embodiment have the same effects as those of the parts having the same configuration. As in the thrust bearing 4 of the present embodiment, the contact portion 420 may have a planar shape. Further, the bearing side oil passage 70 may be opened in the contact portion 420. In addition, the boundary side second section 712 may be recessed on the inner peripheral surface of the thrust bearing arrangement portion 900. According to the thrust bearing 4 of the present embodiment, lubricating oil can be supplied from the boundary side first section 710 to the bearing side first section 700 via the boundary side second section 712.

Sixth Embodiment
The difference between the thrust bearing of this embodiment and the thrust bearing of the fifth embodiment is that a boundary-side third section is disposed instead of the boundary-side second section. Here, only the differences will be described.

  FIG. 10 shows a radial cross-sectional view of a housing assembly provided with the thrust bearing of the present embodiment. In addition, about the site | part corresponding to FIG. 9, it shows with the same code | symbol. As shown in FIG. 10, a boundary side third section 713 is recessed in the contact portion 420 of the thrust bearing 4. The boundary side third section 713 is an oil groove. The boundary side third section 713 extends in the front-rear direction. The boundary side third section 713 communicates the boundary side second section 711 with the bearing side first section 700. The lubricating oil is supplied from the housing side oil passage 905a to the four boundary side first sections 710, (the lubricating oil is spread over the entire circumferential direction by the boundary side second sections 711), four boundary side third sections 713, four The sliding surface 41 is supplied via the bearing side first section 700 and the four bearing side second sections 701.

  The thrust bearing of the present embodiment and the thrust bearing of the fifth embodiment have the same function and effect as for the parts having the same configuration. The boundary side third section 713 may be recessed in the contact portion 420 as in the thrust bearing 4 of the present embodiment. According to the thrust bearing 4 of the present embodiment, lubricating oil can be supplied from the boundary side first section 710 to the bearing side first section 700 via the boundary side second section 711 and the boundary side third section 713.

<Others>
The embodiments of the thrust bearing according to the present invention have been described above. However, the embodiment is not particularly limited to the above embodiment. It is also possible to carry out in various variants and modifications which can be carried out by those skilled in the art.

  Surfaces defining the boundary side oil passage 71 (for example, large diameter inner peripheral surface 901a, large diameter step surface 901b, non-contact portion 421, medium diameter inner peripheral surface 902a, medium diameter step surface 902b, front and rear surfaces of thrust bearing 4 You may arrange an oil holding part in etc.). In this way, the oil retention in the boundary side oil passage 71 can be improved. For example, the oil retaining portion may be disposed in the boundary side first section 710. The oil retaining portion can be formed, for example, by applying unevenness (embossing, embossing, hairline processing, dimple processing, etc.) to the surface that divides the boundary side oil passage 71.

  The division method of the boundary side oil passage 71 is not particularly limited. Inner surface (inner circumferential surface (large diameter inner circumferential surface 901a, middle diameter inner circumferential surface 902a, small diameter inner circumferential surface 903a) of thrust bearing arrangement portion 900, step surface (large diameter step surface 901b, middle diameter step surface 902b, small diameter step) The difference in shape between the surface 903b) and the outer surface of the thrust bearing 4 (the outer peripheral surface 42 (contact portion 420, non-contact portion 421, front surface, rear surface)) Boundary side oil passage 71 may be defined using the above. When the groove-like boundary side oil passage 71 (the boundary side first section 710, the boundary side second sections 711 and 712, and the boundary side third section 713) is arranged, the inner surface of the thrust bearing arrangement portion 900 and the thrust bearing 4 The boundary side oil passage 71 may be recessed in at least one of the outer surfaces. The communication target of the boundary side second sections 711 and 712 is not particularly limited. For example, the plurality of boundary side first sections 710 may be communicated with each other. Further, the plurality of bearing side first sections 700 may be communicated with each other. Further, the boundary side first section 710 and the bearing side first section 700 may be communicated with each other.

  The bearing side first section 700 of the bearing side oil passage 70 may extend in a direction including the radial direction. That is, as long as it includes the radial direction, it may extend in the direction including at least one of the axial direction and the circumferential direction. The bearing side second section 701 of the bearing side oil passage 70 may extend in the direction including the axial direction. That is, as long as the axial direction is included, it may extend in the direction including at least one of the radial direction and the circumferential direction.

  The boundary side second sections 711 and 712 of the boundary side oil passage 71 may extend in the direction including the circumferential direction. That is, as long as it includes the circumferential direction, it may extend in the direction including at least one of the axial direction and the radial direction. The boundary side third section 713 of the boundary side oil passage 71 may extend in the direction including the axial direction. That is, as long as the axial direction is included, it may extend in the direction including at least one of the radial direction and the circumferential direction.

  The shape and the like (shape, size, position, number of arrangement, etc.) of the contact portion 420 are not particularly limited. Similarly, the shape or the like of the non-contact portion 421 is not particularly limited. Seeing from the front side, the thrust bearing 4 may have an endless ring shape. For example, it may be horseshoe-shaped (C-shaped). The shapes and the like of the tapered portion 410 and the land portion 411 in the sliding surface 41 are not particularly limited. The thrust collar 53 may be integral. The deflector 61 may not be disposed in the turbocharger 1.

  1: Turbocharger, 2: Housing assembly, 3: Journal bearing, 4: Thrust bearing, 5: Rotating part, 7: Oil passage, 40: Through hole, 41: Sliding surface, 42: Outer peripheral surface, 50: Rotating shaft , 51: compressor impeller, 52: turbine impeller, 53: thrust collar, 54: color turbo seal ring, 60: retainer, 61: deflector, 70: bearing side oil path, 71: boundary side oil path, 90: bearing housing ( Counterpart member), 91: compressor housing, 92: turbine housing, 410: taper portion, 411: land portion, 420: contact portion, 421: non-contact portion, 530: collar main body, 530a: cylindrical portion, 530b: flange portion , 531: flange, 600: bottom wall portion, 600a: through hole, 600b: ring seal, 601: peripheral wall portion, 601a Through hole, 610: through hole, 611: discharge hole, 700: bearing side first section, 701: bearing side second section, 710: boundary side first section, 711: boundary side second section, 712: boundary side second Two sections, 713: third section on the boundary side, 900: thrust bearing arrangement portion, 901: large diameter portion, 901a: large diameter inner peripheral surface (inner peripheral surface of mating member), 901b: large diameter step surface, 902: Medium diameter portion 902a: Medium diameter inner peripheral surface (inner peripheral surface of mating member) 902b: Medium diameter step surface, 903: Small diameter portion, 903a: Small diameter inner peripheral surface, 903b: Small diameter step surface, 904: Journal bearing Arrangement part, 905a: housing side oil passage, 905b: housing side oil passage, A: axial center, O: lubricating oil

Claims (6)

A sliding surface supporting an axial thrust load acting on the rotation shaft via an oil film;
A bearing side oil passage through which the lubricating oil for forming the oil film flows;
A thrust bearing comprising
The bearing according to claim 1, wherein the bearing-side oil passage extends in a direction including at least a radial direction, and has a bearing-side first section opened in an outer peripheral surface of the thrust bearing. The outer peripheral surface of the thrust bearing and the inner peripheral surface of the mating member are radially opposed,
The outer circumferential surface of the thrust bearing has a contact portion contacting the inner circumferential surface of the mating member and a non-contact portion not contacting the inner circumferential surface of the mating member,
A boundary-side first section is partitioned in a gap between the non-contact portion and the inner circumferential surface of the mating member,
The thrust bearing according to claim 1, wherein the bearing-side first section is open to at least one of the contact portion and the non-contact portion.   The thrust bearing according to claim 2, wherein the bearing-side first section opens to the non-contact portion and communicates with the boundary-side first section.   The thrust bearing according to claim 3, wherein a single first bearing-side first section is opened in a single non-contact portion.   The thrust bearing according to claim 3, wherein a plurality of the bearing-side first sections are opened in a single non-contact portion. The bearing-side first section opens to the contact portion,
The gap between the contact portion and the inner circumferential surface of the mating member extends in the direction including at least the circumferential direction, and communicates the bearing-side first section and the boundary-side first section. The thrust bearing according to claim 2, wherein the second boundary side is divided.

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