JP2016180324A - Exhaust turbocharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust turbocharger capable of suppressing the leakage of lubricant to a turbine side.SOLUTION: An exhaust turbocharger comprises: a turbine 12; a compressor; a rotary shaft 14; and a housing 15, and also comprises: radial bearings 21, 22 rotatably supporting a turbine-12-side end portion and a compressor-13-side end portion of the rotary shaft 14 within the housing 15, respectively; a lubricant supply passage 40 supplying lubricant to the radial bearing 21; and a lubricant discharge passage 60 that has a proximal end portion communicating with a fifth space section S5 closer to the turbine 12 side than the radial bearing 21 and a distal end portion communicating with a third space section S3 accommodating the rotary shaft 14.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an exhaust turbine supercharger that performs supercharging using exhaust gas discharged from an engine.

  In the supercharger, a turbine and a compressor are integrally connected by a rotating shaft, and the turbine and the compressor are rotatably accommodated in a housing. The exhaust gas is supplied into the housing, and the rotating shaft is driven and rotated by rotating the turbine, thereby driving the compressor. The compressor sucks air from the outside, pressurizes it with an impeller to form compressed air, and supplies the compressed air to a diesel engine or the like.

  In such a compressor, the rotating shaft is rotatably supported by a housing by a turbine-side bearing and a compressor-side bearing, and lubricating oil is supplied to the bearings from the outside. In this case, the turbine is heated because it is in contact with the high-temperature exhaust gas, and the lubricating oil is heated via the bearing to a high temperature. When the lubricating oil becomes high temperature, it becomes difficult to support the rotating shaft appropriately and rotatably, for example, solidify and adhere to the rotating shaft and bearings to carbonize or generate white smoke.

  As what solves such a problem, there exists a thing described in the following patent document 1, for example. The supercharger described in Patent Document 1 is provided with a cooling air chamber adjacent to a turbine in a casing, and a cooling air passage for feeding a part of the outside air pressure-fed by a compressor is connected to the cooling air chamber, and cooling is performed. A discharge port that leads to a space between the casing and the turbine impeller is provided in the air chamber. Therefore, a bearing, a lubrication system, etc. can be cooled by supplying cooling air into the casing from the discharge port of the cooling air chamber.

Japanese Patent No. 4247082

  A rotating shaft connecting the turbine and the compressor is rotatably supported by a housing by each bearing, and lubricating oil is supplied from the outside to each bearing. However, since the turbine side in the housing has a negative pressure, the lubricating oil supplied to the turbine-side bearing may leak to the turbine side.

  This invention solves the subject mentioned above, and it aims at providing the exhaust turbine supercharger which suppresses the leak to the turbine side of lubricating oil.

  In order to achieve the above object, an exhaust turbine supercharger according to the present invention includes a turbine, a compressor, a rotating shaft that coaxially connects the turbine and the compressor, the turbine, the compressor, and the rotating shaft. A housing for housing, a turbine-side bearing and a compressor-side bearing for rotatably supporting the turbine-side end portion and the compressor-side end portion of the rotating shaft in the housing, and the turbine-side bearing and the compressor-side Lubricating oil supply passage for supplying lubricating oil to the bearing, and a lubricating oil discharge passage having a base end portion communicating with the space portion on the turbine side from the turbine side bearing and a distal end portion communicating with the space portion housing the rotating shaft These are provided.

  Accordingly, the lubricating oil is supplied to the turbine side bearing and the compressor side bearing through the lubricating oil supply passage. The lubricating oil supplied to the turbine side bearing tends to be sucked by the negative pressure on the turbine side. However, since there is provided a lubricating oil discharge passage that communicates from the turbine-side space portion to the space portion that houses the rotating shaft from the turbine-side bearing, the lubricating oil supplied to the turbine-side bearing is separated from the turbine-side bearing. After the bearing surface with the rotating shaft is lubricated, the lubricating oil is discharged through the lubricating oil discharge passage to the space portion housing the rotating shaft, and leakage of the lubricating oil to the turbine side can be suppressed.

  In the exhaust turbine supercharger according to the present invention, a first seal portion is provided between the housing and the boss portion of the turbine, and a base end portion of the lubricant discharge passage is at the turbine side bearing and the first seal. It is characterized in that it communicates with a space part between the parts.

  Accordingly, since the first seal portion is provided between the housing and the boss portion of the turbine, the lubricating oil supplied to the turbine side bearing can suppress leakage to the turbine side by the first seal portion. .

  In the exhaust turbine supercharger according to the present invention, a second seal portion is provided between the housing and the blade portion of the turbine, and seal air is provided in a space portion between the first seal portion and the second seal portion. Is provided with a seal air supply passage.

  Accordingly, the seal air is supplied to the space portion between the first seal portion and the second seal portion through the seal air supply passage, and a part of the seal air passing through the first seal portion is the space portion of the turbine side bearing. The lubricating oil supplied to the turbine side bearing can suppress leakage to the turbine side by this seal air.

  In the exhaust turbine supercharger according to the present invention, a lubricating oil reservoir is provided around a space between the turbine-side bearing and the first seal portion in the housing, and the lubricating oil discharge passage has a base end portion. Is communicated with the lubricating oil reservoir.

  Therefore, the lubricating oil supplied to the turbine-side bearing is temporarily stored in the lubricating oil storage section provided in the space section, and then discharged from the lubricating oil discharge passage to the space section side that houses the rotating shaft. Thus, leakage of the lubricating oil to the turbine side can be suppressed.

  In the exhaust turbine supercharger of the present invention, the lubricating oil reservoir is provided in a concave shape along a circumferential direction below a space between the turbine-side bearing and the first seal portion. It is a feature.

  Accordingly, by providing the lubricating oil reservoir in a concave shape along the circumferential direction below the space, the lubricating oil reservoir is provided at the minimum necessary position, thereby suppressing an increase in processing cost. Can do.

  In the exhaust turbine supercharger according to the present invention, an oil drain portion that protrudes in a radial direction is provided on the rotary shaft that faces the lubricating oil reservoir.

  Accordingly, the lubricating oil supplied to the turbine-side bearing moves along the surface of the rotating shaft, but the lubricating oil that moves along the surface of the rotating shaft is transferred to the oil by providing an oil drainage portion on the rotating shaft. The cutting part separates from the rotating shaft and falls to the lubricating oil storage part, and leakage of the lubricating oil to the turbine side can be suppressed.

  In the exhaust turbine supercharger according to the present invention, an oil drain portion protruding in an axial direction or a radial direction is provided at a boss portion of the turbine facing the lubricating oil storage portion.

  Accordingly, the lubricating oil supplied to the turbine-side bearing moves along the surface of the rotating shaft, but the lubricating oil that moves along the surface of the rotating shaft is transferred by providing the oil drainage portion at the boss portion of the turbine. By this oil drainage part, it will separate from the rotating shaft and fall into the lubricating oil storage part, and leakage of lubricating oil to the turbine side can be suppressed.

  In the exhaust turbine supercharger of the present invention, the lubricating oil discharge passage is characterized in that a tip portion opens in a vertical wall of a space portion that houses the rotating shaft.

  Therefore, the lubricating oil supplied to the turbine side bearing is discharged from the opening formed in the vertical wall on the space portion side that accommodates the rotating shaft from the lubricating oil discharge passage, and the lubricating oil can be discharged efficiently. it can.

  In the exhaust turbine supercharger according to the present invention, a lubricating oil circulation line for supplying lubricating oil discharged from a lower portion of the housing to the lubricating oil supply passage is provided.

  Accordingly, the lubricating oil discharged to the housing is returned to the lubricating oil supply passage by the lubricating oil circulation line, so that the space that accommodates the rotating shaft can be set to a negative pressure, and the lubricating oil supplied to the turbine-side bearing is supplied. Oil can be efficiently discharged from the lubricating oil discharge passage.

  According to the exhaust turbine supercharger of the present invention, since the lubricating oil discharge passage that communicates from the turbine-side space portion to the space portion that accommodates the rotating shaft from the turbine-side bearing is provided, leakage of the lubricating oil to the turbine side is suppressed. can do.

FIG. 1 is a schematic cross-sectional view illustrating an exhaust turbine supercharger according to a first embodiment. FIG. 2 is a cross-sectional view of a main part of the exhaust turbine supercharger. FIG. 3 is a cross-sectional view showing an oil pocket. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3 showing an oil pocket. FIG. 5 is a cross-sectional view illustrating a modified example of the oil pocket. FIG. 6 is a cross-sectional view of a main part of the exhaust turbine supercharger according to the second embodiment. FIG. 7 is a cross-sectional view of a main part of the exhaust turbine supercharger according to the third embodiment. FIG. 8 is a cross-sectional view of a main part of the exhaust turbine supercharger according to the fourth embodiment.

  Exemplary embodiments of an exhaust turbine supercharger according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, and when there are two or more embodiments, what comprises combining each embodiment is also included.

[First Embodiment]
FIG. 1 is a schematic cross-sectional view illustrating an exhaust turbine supercharger according to a first embodiment.

  In the first embodiment, the exhaust turbine supercharger is configured so that the compressor and the turbine are integrally rotated, the turbine is rotated by the exhaust gas discharged from the marine diesel engine, and the rotation of the turbine is transmitted. The compressor rotates, and this compressor compresses the combustion gas and supplies it to the engine.

  As shown in FIG. 1, in the exhaust turbine supercharger 11, a turbine 12 and a compressor 13 are integrally connected by a rotating shaft 14 and are housed in a housing 15 so as to be freely rotatable.

  The housing 15 has a hollow shape, and is divided into a first space S1 that houses the turbine 12, a second space S2 that houses the compressor 13, and a third space S3 that houses the rotating shaft 14. . The third space portion S3 of the housing 15 is located between the first space portion S1 and the second space portion S2, and the rotation shaft 14 is disposed. The rotating shaft 14 is rotatably supported at its end on the turbine 12 side by a radial bearing 21 which is a turbine side bearing, and at its end on the compressor 13 is freely rotatable by a radial bearing 22 and a thrust bearing 23 which are compressor side bearings. It is supported by.

  The rotating shaft 14 has a turbine disk 24 fixed to one end portion in the axial direction. The turbine disk 24 is accommodated in the first space S1, and a plurality of turbine blades 25 having an axial flow type in the outer peripheral portion are arranged in the circumferential direction. Are provided at predetermined intervals.

  The housing 15 is provided with an exhaust gas inlet passage 26 and an exhaust gas outlet passage 27 with respect to the turbine blade 25. Further, the housing 15 is provided with a turbine nozzle 28 between the inlet passage 26 and the turbine blade 25, and the axial exhaust gas flow statically expanded by the turbine nozzle 28 is guided to the plurality of turbine blades 25. Thus, the turbine 12 can be driven to rotate.

  The rotary shaft 14 has a compressor impeller 31 fixed to the other end in the axial direction. The compressor impeller 31 is accommodated in the second space S2, and a plurality of blades 32 are arranged in the circumferential direction on the outer peripheral portion. It is provided at intervals.

  The housing 15 is provided with an air intake port 33 and a compressed air discharge port 34 with respect to the compressor impeller 31. Further, the housing 15 is provided with a diffuser 35 between the compressor impeller 31 and the compressed air discharge port 34. The air compressed by the compressor impeller 31 is discharged through the diffuser 35.

  Accordingly, the exhaust gas from the marine diesel engine passes through the exhaust gas inlet passage 26 and is statically expanded by the turbine nozzle 28, and the exhaust gas flow in the axial direction is guided to the plurality of turbine blades 25. The turbine 12 is driven to rotate through the turbine disk 24 to which the turbine blades 25 are fixed. The exhaust gas that has driven the plurality of turbine blades 25 is discharged to the outside from the outlet passage 27. On the other hand, when the rotating shaft 14 is rotated by the turbine 12, the integrated compressor impeller 31 is rotated and air is sucked through the air intake port 33. The sucked air is compressed by the compressor impeller 31 to become compressed air, which passes through the diffuser 35 and is supplied from the compressed air discharge port 34 to the marine diesel engine.

  In the exhaust turbine supercharger 11, the housing 15 is provided with a lubricating oil supply passage 40 for supplying lubricating oil to the radial bearings 21 and 22 and the thrust bearing 23. The lubricating oil supply passage 40 includes a first supply passage 41 extending in the radial direction at the upper portion of the housing 15, a second supply passage 42 extending in the axial direction at the upper portion of the housing 15, and a third supply passage 43 communicating with the radial bearing 21. And a fourth supply passage 44 communicating with the radial bearing 22 and a fifth supply passage 45 communicating with the thrust bearing 23. The first supply passage 41 has a base end connected to a lubricating oil tank (not shown), a distal end communicated with the second supply passage 42, and the second supply passage 42 is connected to the third supply passage 43 and the third supply passage 43. The four supply passages 44 and the fifth supply passage 45 communicate with the base end portions.

  The radial bearings 21 and 22 rotatably support the rotary shaft 14 by inner peripheral surfaces, and the distal ends of the third supply passage 43 and the fourth supply passage 44 are connected to the outer peripheral portion, respectively. The radial bearings 21 and 22 are formed with passages 21 a and 22 a that guide the lubricating oil supplied from the third supply passage 43 and the fourth supply passage 44 to the outer peripheral surface of the rotary shaft 14.

  On the other hand, the housing 15 is connected to the base end portion of the lubricant discharge pipe 46 below the third space S3, and the tip end of the lubricant discharge pipe 46 is connected to an oil pan (not shown). . A lubricating oil circulation line 47 for supplying lubricating oil from the oil pan to the lubricating oil tank is provided, and an oil pump 48 and an oil filter 49 are provided in the lubricating oil circulation line 47.

  The housing 15 is provided with a labyrinth seal 51 as a first seal portion between the boss portion 24 a of the turbine disk 24 in the turbine 12. The housing 15 is provided with a labyrinth seal 52 as a second seal portion between the blade 12 b of the turbine disk 24 in the turbine 12. The housing 15 is provided with a seal air supply passage 53 that supplies seal air to the fourth space S <b> 4 between the labyrinth seal 51 and the labyrinth seal 52. The seal air supply passage 53 includes a seal air chamber 54 and a communication passage 55.

  In the present embodiment, the lubricating oil supplied between the radial bearing 21 and the rotary shaft 14 from the third supply passage 43 of the lubricating oil supply passage 40 through the passage 21a is recovered and discharged to the third space S3. A lubricating oil discharge passage 60 is provided.

  2 is a cross-sectional view of a main part of the exhaust turbine supercharger, FIG. 3 is a cross-sectional view showing an oil pocket, and FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

  In the exhaust turbine supercharger 11, as shown in FIGS. 2 to 4, the lubricating oil discharge passage 60 is provided below the rotary shaft 14 in the housing 15. The lubricating oil discharge passage 60 includes a first discharge passage 61 along the radial direction of the housing 15 and a second discharge passage 62 along the axial direction of the housing 15. In the lubricating oil discharge passage 60, the base end portion of the first discharge passage 61 communicates with the fifth space S <b> 5 on the turbine disk 24 side from the radial bearing 21, and the tip portion communicates with the base end portion of the second discharge passage 62. The tip of the second discharge passage 62 communicates with the third space S3 that accommodates the rotating shaft 14. The fifth space S5 is a space defined by the radial bearing 21 and the labyrinth seal 51. The fifth space S5 has a ring shape. The lubricating oil discharge passage 60 has a base end portion of the first discharge passage 61. The tip of the second discharge passage 62 communicates with the closed fifth space S5 and opens in the vertical wall 15a in the third space S3.

  The housing 15 is provided with an oil pocket 63 as a lubricating oil reservoir around the fifth space S5. The lubricating oil discharge passage 60 has a base end portion of the first discharge passage 61 at the oil pocket 63. Communicating with The oil pocket 63 is provided in a concave shape along the circumferential direction below the fifth space S <b> 5 in the housing 15. That is, the oil pocket 63 is provided so as to be opposed to the outer side in the radial direction with respect to the stepped portion 14 a at the connecting portion of the rotating shaft 14 with the turbine disk 24. The oil pocket 63 is provided below the center of the rotating shaft 14, and is configured by a groove 63 a that is formed at a certain depth along the circumferential direction of the rotating shaft 14. In the lubricating oil discharge passage 60, the base end portion of the first discharge passage 61 opens at the bottom of the groove 63a.

  Note that the shape of the oil pocket 63 is not limited to that described above. FIG. 5 is a cross-sectional view illustrating a modified example of the oil pocket.

  As shown in FIG. 5, the oil pocket 64 is provided in a concave shape along the circumferential direction below the fifth space S <b> 5 in the housing 15. The oil pocket 64 is provided by a groove portion 64 a provided below the center of the rotating shaft 14 and formed so that the depth varies along the circumferential direction of the rotating shaft 14. The groove portion 64 a is deepest at a position below the rotating shaft 14 and is formed so that the depth becomes shallower toward a side position of the rotating shaft 14.

  In the exhaust turbine supercharger 11 configured in this way, the lubricating oil supplied from the lubricating oil tank to the lubricating oil supply passage 40 passes through the first supply passage 41 and the second supply passage 42, the third supply passage 43, 4 is supplied to the fourth supply passage 44 and the fifth supply passage 45. The third supply passage 43 supplies oil to the radial bearing 21, the fourth supply passage 44 supplies oil to the radial bearing 22, and the fifth supply passage 45 supplies oil to the thrust bearing 23.

  On the other hand, the seal air supplied to the seal air supply passage 53 is supplied from the seal air chamber 54 to the fourth space S <b> 4 between the labyrinth seal 51 and the labyrinth seal 52 through the communication passage 55. Then, after the housing 15 and the turbine disk 24 are cooled, a part of the seal air supplied to the fourth space S4 flows from the gap of the labyrinth seal 52 to the outlet passage 27 side, and a part of the seal air is supplied to the labyrinth seal 51. Flows from the gap to the fifth space S5 side.

  At this time, the lubricating oil supplied to the radial bearing 21 lubricates the support surface of the radial bearing 21 and the rotary shaft 14, and then moves the outer peripheral surface of the rotary shaft 14 to the third space portion S 3 side by centrifugal force. Discrete and fall below the housing 15. However, some lubricating oil may move the outer peripheral surface of the rotating shaft 14 toward the fifth space S5. On the other hand, a part of the sealing air supplied to the fourth space S4 flows from the gap of the labyrinth seal 52 toward the fifth space S5. Then, the lubricating oil transferred to the fifth space S5 side through the outer peripheral surface of the rotary shaft 14 is blocked by the seal air flowing from the fourth space S4 through the gap of the labyrinth seal 51 to the fifth space S5. And stored in the oil pocket 63.

  When the exhaust turbine supercharger 11 is driven, since the oil pump 48 of the lubricating oil circulation line 47 is operated, the third space S3 to which the base end portion of the lubricating oil circulation line 47 is connected has a negative pressure. Maintained in a state. Therefore, the negative pressure in the third space S <b> 3 acts on the oil pocket 63 through the lubricating oil discharge passage 60. Then, the lubricating oil stored in the oil pocket 63 is sucked, and this lubricating oil is discharged into the third space S3 through the lubricating oil discharge passage 60 together with the seal air. As a result, the lubricating oil that has entered the fifth space portion S5 is discharged from the oil pocket 63 to the third space portion S3 through the lubricating oil discharge passage 60, and is prevented from moving to the fourth space portion S4 side.

  Thus, in the exhaust turbine supercharger of the first embodiment, the turbine 12, the compressor 13, the rotary shaft 14, and the housing 15 are provided, and the end of the rotary shaft 14 on the turbine 12 side and the end of the compressor 13 side are provided. Radial bearings 21 and 22 that rotatably support the bearings in the housing 15, a lubricating oil supply passage 40 that supplies lubricating oil to the radial bearings 21 and 22, and a base end portion of the radial bearing 21 that is closer to the turbine 12 side. A lubricating oil discharge passage 60 that communicates with the fifth space S5 and that communicates with the third space S3 in which the tip portion accommodates the rotating shaft 14 is provided.

  Accordingly, the lubricating oil is supplied to the radial bearings 21 and 22 through the lubricating oil supply passage 40. The lubricating oil supplied to the radial bearing 21 is sucked to the turbine 12 side after lubricating the bearing surfaces of the radial bearing 21 and the rotary shaft 14 because the turbine 12 side has a negative pressure. However, since the lubricating oil discharge passage 60 that communicates from the fifth space S5 on the turbine 12 side of the radial bearing 21 to the third space S3 that accommodates the rotary shaft 14 is provided, lubrication that lubricates the radial bearing 21 is provided. The oil is discharged to the third space portion S3 side through the lubricating oil discharge passage 60, and leakage of the lubricating oil to the turbine 12 side can be suppressed.

  In the exhaust turbine supercharger of the first embodiment, a labyrinth seal 51 is provided between the housing 15 and the boss portion 24a of the turbine disk 24, and the base end portion of the lubricating oil discharge passage 60 is connected to the radial bearing 21 and the labyrinth seal 51. It communicates with the fifth space portion S5. The lubricating oil supplied to the radial bearing 21 can suppress leakage to the turbine 12 side by the labyrinth seal 51.

  In the exhaust turbine supercharger of the first embodiment, a labyrinth seal 52 is provided between the housing 15 and the outer peripheral portion (wing portion) 24 b of the turbine disk 24, and a fourth space between the labyrinth seal 51 and the labyrinth seal 52 is provided. A seal air supply passage 53 for supplying seal air to the part S4 is provided. Accordingly, the seal air is supplied to the fourth space S4 through the seal air supply passage 53, and a part of the seal air that has passed through the labyrinth seal 51 flows to the fifth space S5, and is supplied to the radial bearing 21. The lubricating oil can suppress leakage to the turbine 12 side by the seal air.

  In the exhaust turbine supercharger of the first embodiment, the oil pocket 63 is provided around the fifth space S5 between the radial bearing 21 and the labyrinth seal 51 in the housing 15, and the base end portion of the lubricating oil discharge passage 60 is provided. It communicates with the oil pocket 63. Therefore, the lubricating oil supplied to the radial bearing 21 is temporarily stored in the oil pocket 63 provided in the fifth space S5, and then discharged from the lubricating oil discharge passage 60 to the third space S3. Therefore, leakage of the lubricating oil to the turbine 12 side can be suppressed.

  In the exhaust turbine supercharger of the first embodiment, the oil pocket 63 is provided in a concave shape along the circumferential direction below the fifth space S5 between the radial bearing 21 and the labyrinth seal 51. Therefore, by providing the oil pocket 63 at the minimum necessary location in the housing 15, an increase in processing cost can be suppressed.

  In the exhaust turbine supercharger of the first embodiment, the tip of the lubricating oil discharge passage 60 is opened in the vertical wall 15a of the third space S3. Accordingly, the lubricating oil supplied to the radial bearing 21 is discharged from the opening formed in the vertical wall 15a on the third space S3 side from the lubricating oil discharge passage 60, and the lubricating oil can be discharged efficiently. it can.

  In the exhaust turbine supercharger of the first embodiment, a lubricating oil circulation line 47 that supplies the lubricating oil discharged from the lower portion of the housing 15 to the lubricating oil supply passage 40 is provided. Therefore, the lubricating oil discharged to the housing 15 is returned to the lubricating oil supply passage 40 by the lubricating oil circulation line 47, and the third space S3 can be maintained at a negative pressure and supplied to the radial bearing 21. The lubricating oil can be efficiently discharged from the lubricating oil discharge passage 60.

[Second Embodiment]
FIG. 6 is a cross-sectional view of a main part of the exhaust turbine supercharger according to the second embodiment. In addition, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above, and detailed description is abbreviate | omitted.

  In the second embodiment, as shown in FIG. 6, the lubricating oil supplied between the radial bearing 21 (see FIG. 1) and the rotating shaft 14 is recovered and discharged into the third space S3 (see FIG. 1). A lubricating oil discharge passage 60 is provided. The housing 15 is provided with an oil pocket 63 as a lubricating oil reservoir around the fifth space S5. The lubricating oil discharge passage 60 has a base end portion of the first discharge passage 61 communicating with the oil pocket 63. ing. The oil pocket 63 is provided opposite to the radially outer side of the rotating shaft 14 with respect to the stepped portion 14 a of the turbine disk 24.

  The rotating shaft 14 is provided with an oil draining ring (oil draining portion) 71 protruding outward in the radial direction on the outer peripheral surface facing the oil pocket 63. The oil drain ring 71 is formed integrally with the outer peripheral portion of the stepped portion 14 a of the rotating shaft 14 in a disc shape. That is, the oil drain ring 71 is set to have a larger outer diameter than the outer diameter of the rotating shaft 14 including the stepped portion 14a.

  Therefore, when the lubricating oil is supplied to the radial bearing 21, the outer peripheral surface of the rotating shaft 14 is shifted to the third space S3 side after lubricating the support surface of the radial bearing 21 and the rotating shaft 14, and by centrifugal force. Discrete and fall below the housing 15. On the other hand, when the seal air is supplied to the fourth space S4, a part flows from the gap of the labyrinth seal 51 toward the fifth space S5.

  Then, the lubricating oil transferred to the fifth space S5 side through the outer peripheral surface of the rotary shaft 14 is blocked by the seal air flowing from the fourth space S4 through the gap of the labyrinth seal 51 to the fifth space S5. And stored in the oil pocket 63. At this time, since the oil drain ring 71 is provided on the rotating shaft 14, the lubricating oil transferred to the fifth space S <b> 5 side through the outer peripheral surface of the rotating shaft 14 from the outer peripheral portion of the oil drain ring 71. It becomes easy to fall into the oil pocket 63.

  Since the third space S3 is maintained in the negative pressure state, the lubricating oil stored in the oil pocket 63 is sucked, and this lubricating oil together with the seal air passes through the lubricating oil discharge passage 60 to form the third space. It is discharged to S3.

  As described above, in the exhaust turbine supercharger according to the second embodiment, the oil pocket 63 is provided around the fifth space S5 in the housing 15, and the base of the lubricating oil discharge passage 60 communicating with the third space S3 is provided. An end portion is connected to the oil pocket 63, and an oil draining ring 71 protruding in the radial direction is provided on the rotary shaft 14 facing the oil pocket 63.

  Therefore, when lubricating oil is supplied to the radial bearing 21, the bearing surface with the rotating shaft 14 is lubricated and then transferred to the fifth space S 5 side along the outer peripheral surface of the rotating shaft 14. Since the oil draining ring 71 is provided, the lubricating oil on the surface of the rotating shaft 14 is separated from the rotating shaft 14 by the oil draining ring 71 and falls into the oil pocket 63, and this lubricating oil is removed from the lubricating oil discharge passage. 60 can be appropriately discharged to the third space S3 side.

[Third Embodiment]
FIG. 7 is a cross-sectional view of a main part of the exhaust turbine supercharger according to the third embodiment. In addition, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above, and detailed description is abbreviate | omitted.

  In the third embodiment, as shown in FIG. 7, the lubricating oil supplied between the radial bearing 21 (see FIG. 1) and the rotating shaft 14 is recovered and discharged into the third space S3 (see FIG. 1). A lubricating oil discharge passage 60 is provided. The housing 15 is provided with an oil pocket 63 as a lubricating oil reservoir around the fifth space S5. The lubricating oil discharge passage 60 has a base end portion of the first discharge passage 61 communicating with the oil pocket 63. ing. The oil pocket 63 is provided opposite to the radially outer side of the rotating shaft 14 with respect to the stepped portion 14 a of the turbine disk 24.

  The turbine disk 24 of the turbine 12 is provided with an oil cut protrusion 73 that protrudes in the axial direction by a notch 72 on the outer peripheral surface of the boss 24 a facing the oil pocket 63. The boss portion 24a of the turbine disk 24 is formed with a semicircular cross-sectional cutout 72 on the end surface of the rotating shaft 14 on the stepped portion 14a side along the circumferential direction. An oil-cut protrusion (oil-cut portion) 73 protruding toward the stepped portion 14a in the direction is provided along the circumferential direction. That is, the oil drain protrusion 73 is set to have a larger outer diameter than the outer diameter of the rotating shaft 14 including the stepped portion 14a.

  Therefore, when the lubricating oil is supplied to the radial bearing 21, the outer peripheral surface of the rotating shaft 14 is shifted to the third space S3 side after lubricating the support surface of the radial bearing 21 and the rotating shaft 14, and by centrifugal force. Discrete and fall below the housing 15. On the other hand, when the seal air is supplied to the fourth space S4, a part flows from the gap of the labyrinth seal 51 toward the fifth space S5.

  Then, the lubricating oil transferred to the fifth space S5 side through the outer peripheral surface of the rotary shaft 14 is blocked by the seal air flowing from the fourth space S4 through the gap of the labyrinth seal 51 to the fifth space S5. And stored in the oil pocket 63. At this time, since the oil cut protrusion 73 is provided on the boss portion 24a of the turbine disk 24, the lubricating oil transferred to the fifth space S5 side along the outer peripheral surface of the rotating shaft 14 is removed from the oil cut protrusion. It becomes easy to fall into the oil pocket 63 from the outer peripheral portion of the portion 73.

  Since the third space S3 is maintained in the negative pressure state, the lubricating oil stored in the oil pocket 63 is sucked, and this lubricating oil together with the seal air passes through the lubricating oil discharge passage 60 to form the third space. It is discharged to S3.

  Thus, in the exhaust turbine supercharger of the third embodiment, the oil pocket 63 is provided around the fifth space S5 in the housing 15, and the base of the lubricating oil discharge passage 60 communicating with the third space S3 is provided. An end portion is communicated with the oil pocket 63, and an oil draining protrusion 73 protruding in the axial direction is provided on the boss portion 24 a of the turbine disk 24 facing the oil pocket 63.

  Accordingly, when the lubricating oil is supplied to the radial bearing 21, the bearing surface with the rotating shaft 14 is lubricated and then transferred to the fifth space S 5 side along the outer peripheral surface of the rotating shaft 14. Since the oil drain protrusion 73 is provided on the boss portion 24a, the lubricating oil on the surface of the rotating shaft 14 is separated from the rotating shaft 14 by the oil drain protrusion 73 and falls into the oil pocket 63. Oil can be appropriately discharged to the third space S3 side by the lubricating oil discharge passage 60.

[Fourth Embodiment]
FIG. 8 is a cross-sectional view of a main part of the exhaust turbine supercharger according to the fourth embodiment. In addition, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above, and detailed description is abbreviate | omitted.

  In the fourth embodiment, as shown in FIG. 8, the lubricating oil supplied between the radial bearing 21 (see FIG. 1) and the rotating shaft 14 is recovered and discharged into the third space S3 (see FIG. 1). A lubricating oil discharge passage 60 is provided. The housing 15 is provided with an oil pocket 63 as a lubricating oil reservoir around the fifth space S5. The lubricating oil discharge passage 60 has a base end portion of the first discharge passage 61 communicating with the oil pocket 63. ing. The oil pocket 63 is provided opposite to the radially outer side of the rotating shaft 14 with respect to the stepped portion 14 a of the turbine disk 24.

  And between the rotating shaft 14 and the turbine disk 24 of the turbine 12, the oil drain ring (oil drain part) 74 which protrudes to the outward of a radial direction facing the oil pocket 63 is provided. The oil drain ring 74 has a disk shape between the stepped portion 14a of the rotating shaft 14 and the boss portion 24a of the turbine disk 24, and has a tapered shape with a tapered outer peripheral portion. That is, the oil drain ring 74 has an outer diameter that is larger than the outer diameter of the rotating shaft 14 including the stepped portion 14a and the outer diameter of the boss portion 24a.

  Therefore, when the lubricating oil is supplied to the radial bearing 21, the outer peripheral surface of the rotating shaft 14 is shifted to the third space S3 side after lubricating the support surface of the radial bearing 21 and the rotating shaft 14, and by centrifugal force. Discrete and fall below the housing 15. On the other hand, when the seal air is supplied to the fourth space S4, a part flows from the gap of the labyrinth seal 51 toward the fifth space S5.

  Then, the lubricating oil transferred to the fifth space S5 side through the outer peripheral surface of the rotary shaft 14 is blocked by the seal air flowing from the fourth space S4 through the gap of the labyrinth seal 51 to the fifth space S5. And stored in the oil pocket 63. At this time, since the oil draining ring 74 is provided between the rotating shaft 14 and the turbine disk 24, the lubricating oil transferred to the fifth space S5 side along the outer peripheral surface of the rotating shaft 14 is the oil. It becomes easy to fall into the oil pocket 63 from the outer periphery of the cutting ring 74.

  Since the third space S3 is maintained in the negative pressure state, the lubricating oil stored in the oil pocket 63 is sucked, and this lubricating oil together with the seal air passes through the lubricating oil discharge passage 60 to form the third space. It is discharged to S3.

  Thus, in the exhaust turbine supercharger of the fourth embodiment, the oil pocket 63 is provided around the fifth space S5 in the housing 15, and the base of the lubricating oil discharge passage 60 communicating with the third space S3 is provided. An end portion is communicated with the oil pocket 63, and an oil draining ring 74 protruding in the radial direction is provided between the rotating shaft 14 facing the oil pocket 63 and the turbine disk 24.

  Therefore, when lubricating oil is supplied to the radial bearing 21, the bearing surface with the rotary shaft 14 is lubricated and then transferred to the fifth space S5 side along the outer peripheral surface of the rotary shaft 14. Since the oil drain ring 74 is provided between the turbine disk 24 and the lubricating oil on the surface of the rotating shaft 14, the lubricating oil is separated from the rotating shaft 14 by the oil drain ring 74 and falls into the oil pocket 63. The lubricating oil can be properly discharged to the third space portion S3 side by the lubricating oil discharge passage 60.

  In this embodiment, the lubricating oil discharge passage 60 is composed of the first discharge passage 61 along the radial direction of the housing 15 and the second discharge passage 62 along the axial direction of the housing 15. However, the configuration is limited to this configuration. Is not to be done. For example, the second discharge passage may be inclined radially outward with respect to the axial direction of the housing 15, and the lubricating oil can be discharged efficiently by its own weight. Further, the lubricating oil discharge passage itself may be an inclined passage, a curved passage, or the like.

  In the above-described embodiment, the oil pocket 63 as the lubricating oil reservoir is provided around the fifth space S5 in the housing 15, but the shape of the oil pocket 63 is not limited to each embodiment. . Further, the base end portion of the lubricating oil discharge passage 60 may be directly communicated with the fifth space portion S5 without providing the lubricating oil storage portion. In this case, the inner diameter of the lubricating oil discharge passage 60 is set to the fifth space portion S5. It is desirable to gradually expand toward

11 Exhaust turbine supercharger 12 Turbine 13 Compressor 14 Rotating shaft 15 Housing 21 Radial bearing (turbine side bearing)
22 Radial bearing (compressor side bearing)
23 Thrust bearing 40 Lubricating oil supply passage 41 First supply passage 42 Second supply passage 43 Third supply passage 44 Fourth supply passage 45 Fifth supply passage 46 Lubricant oil discharge pipe 47 Lubricant oil circulation line 51 Labyrinth seal (first seal) Part)
52 Labyrinth seal (second seal)
53 Seal air supply passage 54 Seal air chamber 55 Communication passage 60 Lubricating oil discharge passage 61 First discharge passage 62 Second discharge passage 63, 64 Oil pocket (lubricating oil reservoir)
71,74 Oil drain ring (oil drain)
72 Notch 73 Oil cut protrusion (oil cut)
S1 1st space part S2 2nd space part S3 3rd space part S4 4th space part S5 5th space part

Claims (9)

A turbine,
A compressor,
A rotating shaft that coaxially connects the turbine and the compressor;
A housing that houses the turbine, the compressor, and the rotating shaft;
A turbine-side bearing and a compressor-side bearing that rotatably support the turbine-side end portion and the compressor-side end portion of the rotating shaft in the housing, respectively.
A lubricating oil supply passage for supplying lubricating oil to the turbine side bearing and the compressor side bearing;
A lubricating oil discharge passage in which a base end portion communicates with a space portion on the turbine side from the turbine side bearing and a distal end portion communicates with a space portion accommodating the rotating shaft;
An exhaust turbine supercharger comprising:   A first seal portion is provided between the housing and the boss portion of the turbine, and a base end portion of the lubricant discharge passage communicates with a space portion between the turbine side bearing and the first seal portion. The exhaust turbine supercharger according to claim 1.   A second seal portion is provided between the housing and the blade portion of the turbine, and a seal air supply passage for supplying seal air to a space portion between the first seal portion and the second seal portion is provided. The exhaust turbine supercharger according to claim 2.   A lubricating oil reservoir is provided around a space between the turbine-side bearing and the first seal portion in the housing, and a base end portion of the lubricating oil discharge passage communicates with the lubricating oil reservoir. The exhaust turbine supercharger according to claim 2 or claim 3, wherein   5. The exhaust according to claim 4, wherein the lubricating oil storage portion is provided in a concave shape along a circumferential direction below a space portion between the turbine side bearing and the first seal portion. Turbine supercharger.   6. The exhaust turbine supercharger according to claim 4, wherein an oil drain portion that protrudes in a radial direction is provided on the rotating shaft that faces the lubricating oil storage portion.   The exhaust turbine according to any one of claims 4 to 6, wherein an oil drain portion protruding in an axial direction or a radial direction is provided at a boss portion of the turbine facing the lubricating oil storage portion. Turbocharger.   The exhaust turbine supercharger according to any one of claims 1 to 7, wherein the lubricating oil discharge passage has a front end portion that opens in a vertical wall of a space portion that accommodates the rotating shaft.   The exhaust turbine supercharging according to any one of claims 1 to 8, wherein a lubricating oil circulation line for supplying lubricating oil discharged from a lower portion of the housing to the lubricating oil supply passage is provided. Machine.

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