JP6990754B2 - Supercharger - Google Patents

Description

The present invention is applied to a thrust bearing device that rotatably supports a rotating shaft and receives a thrust load acting in the axial direction of the rotating shaft in a supercharger in which a turbine and a compressor are connected by a rotating shaft. It is about the supercharger to be done.

The exhaust turbine supercharger is configured such that a compressor and a turbine are integrally connected by a rotating shaft, and the compressor and the turbine are rotatably housed in a housing. Then, the exhaust gas is supplied into the housing, and by rotating the turbine, the rotating shaft is driven and rotated, and the compressor is driven to rotate. The compressor sucks air from the outside and pressurizes it with an impeller to make compressed air, and supplies this compressed air to an internal combustion engine or the like.

In such an exhaust turbine supercharger, the rotating shaft is rotatably supported by a journal bearing and a thrust bearing with respect to the housing. In a conventional thrust bearing device, a thrust sleeve and a thrust ring fixed to the outer peripheral portion of a rotating shaft and a thrust bearing having an outer peripheral portion fixed to a housing and an inner peripheral portion fitted between the thrust sleeve and the thrust ring are used. It is configured. Therefore, the thrust load acting on one side of the rotating shaft in the axial direction is received by the thrust bearing via the thrust sleeve, and the thrust load acting on the other side in the axial direction of the rotating shaft is received by the thrust bearing via the thrust ring. Take it.

As such a thrust bearing device, for example, there is one described in the following Patent Document 1.

Japanese Unexamined Patent Publication No. 2013-002559

Generally, the thrust load increases as the rotation speed of the turbocharger increases. At this time, it is considered that the increase rate in the low rotation range is high and the increase rate in the high rotation range is low. Was there. That is, when the fluctuation of the thrust load with respect to the increase in the number of revolutions is represented by a graph, it can be represented by a curved shape having a convex shape upward. However, in reality, the rate of increase in the low rpm range is low and the rate of increase in the high rpm range is high. It becomes a curved shape like. Therefore, there is a difference between the fluctuation of the thrust load with respect to the rotation speed at the time of design and the fluctuation of the thrust load with respect to the actual rotation speed, and there is a possibility that the load capacity of the thrust bearing device does not adapt to the load actually acting on the rotating shaft. be.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide a turbocharger for making a device compact by adapting a load capacity to a load actually acting on a rotating shaft.

In order to achieve the above object, the supercharger of the present invention has a hollow housing, a rotating shaft rotatably supported by the housing, and a turbine provided at one end of the rotating shaft in the axial direction. A compressor provided at the other end of the rotating shaft in the axial direction, a pressure adjusting space provided in a ring shape between the compressor back surface side and the housing, and a space on the discharge port side of the compressor. It is characterized by having a first seal gap provided between the portion and the pressure adjusting space portion, and a second seal gap provided between the pressure adjusting space portion and the rotary shaft side space portion. It is something to do.

Therefore, when the pressure in the space on the discharge port side becomes high, a thrust load acts on the rotating shaft via the compressor to the turbine side, and the first seal gap becomes large, while the second seal gap becomes small, for pressure adjustment. The pressure in the space increases. When the pressure in the pressure adjusting space becomes high, a thrust load on the compressor side acts on the rotating shaft via the compressor. As a result, the thrust load can be reduced by the differential pressure between the discharge port side space and the pressure adjustment space, and the load capacity is adapted to the load that actually acts on the rotating shaft to make the device more compact. be able to.

According to the turbocharger of the present invention, the device can be made compact by adapting the load capacity to the load actually acting on the rotating shaft.

FIG. 1 is an overall configuration diagram showing an exhaust turbine turbocharger according to the first embodiment. FIG. 2 is a cross-sectional view showing the thrust bearing device of the first embodiment. FIG. 3 is a cross-sectional view showing the operation of the thrust bearing device. FIG. 4 is a cross-sectional view showing the operation of the thrust bearing device. FIG. 5 is a graph showing the thrust load with respect to the turbocharger rotation speed. FIG. 6 is a cross-sectional view showing the thrust bearing device of the second embodiment. FIG. 7 is a cross-sectional view showing the thrust bearing device of the third embodiment. FIG. 8 is a graph showing the thrust load with respect to the turbocharger rotation speed.

Hereinafter, preferred embodiments of the thrust bearing device and the turbocharger according to the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to this embodiment, and when there are a plurality of embodiments, the present invention also includes a combination of the respective embodiments.

[First Embodiment]
FIG. 1 is an overall configuration diagram showing an exhaust turbine turbocharger according to the first embodiment, and FIG. 2 is a cross-sectional view showing a thrust bearing device according to the first embodiment.

As shown in FIG. 1, the exhaust turbine supercharger 11 is mainly composed of a turbine 12, a compressor 13, and a rotating shaft 14, and these are housed in a housing 15.

The housing 15 is formed to have a hollow interior, and has a turbine housing 15A forming a first space portion S1 accommodating the configuration of the turbine 12 and a compressor housing 15B forming a second space portion S2 accommodating the configuration of the compressor 13. It has a bearing housing 15C forming a third space portion S3 for accommodating the shaft 14. The third space portion S3 of the bearing housing 15C is located between the first space portion S1 of the turbine housing 15A and the second space portion S2 of the compressor housing 15B.

The end of the rotary shaft 14 on the turbine 12 side is rotatably supported by the journal bearing 21 which is the turbine side bearing, and the end on the compressor 13 side is rotatably supported by the journal bearing 22 which is the compressor side bearing. , The thrust bearing 23 regulates the axial movement of the rotating shaft 14 extending. The turbine disk 24 of the turbine 12 is fixed to one end of the rotating shaft 14 in the axial direction. The turbine disk 24 is housed in the first space portion S1 of the turbine housing 15A, and a plurality of turbine blades 25 forming an axial flow type are provided on the outer peripheral portion at predetermined intervals in the circumferential direction. Further, the compressor impeller 26 of the compressor 13 is fixed to the other end of the rotating shaft 14 in the axial direction. The compressor impeller 26 is housed in the second space portion S2 of the compressor housing 15B, and a plurality of blades 27 are provided on the outer peripheral portion at predetermined intervals in the circumferential direction.

The turbine housing 15A is provided with an exhaust gas inlet passage 31 and an exhaust gas outlet passage 32 for the turbine blade 25. The turbine housing 15A is provided with a turbine nozzle 33 between the inlet passage 31 and the turbine blade 25, and the axial exhaust gas flow statically expanded by the turbine nozzle 33 is applied to the plurality of turbine blades 25. By being guided, the turbine 12 can be driven and rotated. The compressor housing 15B is provided with a suction port 34 and a compressed air discharge port 35 for the compressor impeller 26. The compressor housing 15B is provided with a diffuser 36 between the compressor impeller 26 and the compressed air discharge port 35. The air compressed by the compressor impeller 26 is discharged through the diffuser 36.

Therefore, in the exhaust turbine supercharger 11, the turbine 12 is driven by the exhaust gas discharged from the engine (not shown), the rotation of the turbine 12 is transmitted to the rotating shaft 14, and the compressor 13 is driven, and the compressor 13 is driven. Compresses the combustion gas and supplies it to the engine. Therefore, the exhaust gas from the engine passes through the inlet passage 31 of the exhaust gas, is statically expanded by the turbine nozzle 33, and the exhaust gas flow in the axial direction is guided to the plurality of turbine blades 25, whereby the plurality of turbine blades 25 The turbine 12 is driven and rotated via the turbine disk 24 to which the turbine disk 24 is fixed. Then, the exhaust gas that drives the plurality of turbine blades 25 is discharged to the outside from the outlet passage 32. On the other hand, when the rotating shaft 14 is rotated by the turbine 12, the integrated compressor impeller 26 is rotated and air is sucked through the suction port 34. The sucked air is pressurized by the compressor impeller 26 to become compressed air, and this compressed air passes through the diffuser 36 and is supplied to the engine from the compressed air discharge port 35.

In the exhaust turbine supercharger 11 described above, as shown in FIGS. 1 and 2, the thrust bearing device 40 of the first embodiment includes a thrust sleeve (cylinder member) 41, a thrust ring (cylinder member) 42, and the thrust bearing device 40. It includes a thrust bearing 23 and a leaf spring 43.

The rotary shaft 14 is provided with a large diameter portion 14A supported by the journal bearings 21 and 22 and a small diameter portion 14B supported by the thrust bearing 23, and a stepped portion is provided between the large diameter portion 14A and the small diameter portion 14B. 14C is provided. The thrust bearing 23 has a disk shape in which a through hole 23a through which the rotating shaft 14 penetrates is formed, and is provided with pressure receiving surfaces 23A and 23B on each plane side which are substantially orthogonal to the axial direction of the rotating shaft 14.

The thrust sleeve 41 is fixed to the outer peripheral portion of the small diameter portion 14B of the rotating shaft 14 so as to be relatively immovable in the circumferential direction and the axial direction. The thrust sleeve 41 is composed of a sleeve body 51 having a cylindrical shape and a flange portion 52 having a disk shape and integrally provided on one side in the axial direction of the sleeve body 51. Further, the thrust ring 42 is fixed to the outer peripheral portion of the small diameter portion 14B of the rotating shaft 14 so as to be relatively immovable in the circumferential direction and the axial direction. The thrust ring 42 is composed of a ring body 53 having a cylindrical shape and a flange portion 54 having a disk shape and integrally provided on one side in the axial direction of the ring body 53. In the thrust sleeve 41 and the thrust ring 42, the sleeve body 51 and the ring body 53 are arranged in series in the axial direction of the rotation shaft 14, and one end of the sleeve body 51 and one end of the ring body 53 are in contact with each other. Further, in the thrust sleeve 41, the other end of the sleeve body 51 is in contact with the back surface 26a of the compressor impeller 26, and in the thrust ring 42, the other end of the ring body 53 is on the end surface of the stepped portion 14C of the rotating shaft 14. It is in contact.

By fixing the thrust sleeve 41 and the thrust ring 42 in series to the outer peripheral portion of the rotating shaft 14, a predetermined gap S4 along the axial direction of the rotating shaft 14 is provided between the flange portions 52 and 54. The outer peripheral portion of the thrust bearing 23 is fixed to the bearing housing 15C, and the inner peripheral portion is arranged in the predetermined gap S4. The leaf spring 43 has a disk shape having a through hole at the center thereof, the outer peripheral portion thereof is fixed to the bearing housing 15C, and the inner peripheral portion is in contact with the flange portion 52 of the thrust sleeve 41. That is, the leaf spring 43 presses the thrust sleeve 41 toward the thrust ring 42 side via the flange portion 52 by its own urging force.

Then, in the present embodiment, the thrust bearing device 40 of the first embodiment has the flange portions 52, 54 of the thrust sleeve 41 and the thrust ring 42 when a load is applied to one side of the rotating shaft 14 in the axial direction. Is provided with a deformed portion that increases the contact area between the flange portions 52 and 54 and the thrust bearing 23 by deforming.

The thrust sleeve 41 is provided with an outer peripheral side inclined surface 61, an inner peripheral side inclined surface 62, a top portion 63, and a thin-walled portion 64. The outer peripheral side inclined surface 61 is provided on the surface of the flange portion 52 facing the thrust bearing 23, and is arranged on the outer peripheral portion side so that the outer diameter side is separated from the pressure receiving surface 23A of the thrust bearing 23 as compared with the inner diameter side. It has a flat inclined surface that forms a shape. The inner peripheral side inclined surface 62 is provided on the surface of the flange portion 52 facing the thrust bearing 23, and is arranged on the inner peripheral portion side so that the inner diameter side is separated from the pressure receiving surface 23A of the thrust bearing 23 as compared with the outer diameter side. It has a flat slope with a smooth ring shape. The top portion 63 is a ring-shaped apex provided between the outer peripheral side inclined surface 61 and the inner peripheral side inclined surface 62. Since the outer peripheral side inclined surface 61 and the inner peripheral side inclined surface 62 are inclined in the radial direction with respect to the pressure receiving surface 23A of the thrust bearing 23, the top portion 63 comes into contact with the pressure receiving surface 23A of the thrust bearing 23. There is. The inclined surfaces 61 and 62 may be curved surfaces curved in the radial direction.

The thin-walled portion 64 is provided in a ring shape at the connecting portion between the sleeve main body 51 and the flange portion 52. The thin-walled portion 64 is set so that the thickness of the rotating shaft 14 in the axial direction is thinner than the thickness of the rotating shaft 14 in the flange portion 52 in the axial direction. Therefore, when a thrust load acts on the flange portion 52, the thrust sleeve 41 can be elastically deformed in the axial direction of the rotation shaft 14 with the thin wall portion 64 as a fulcrum with respect to the sleeve main body 51. Therefore, this thin-walled portion 64 functions as the above-mentioned deformed portion.

Further, the thrust ring 42 is provided with an inclined surface 65, a top portion 66, and a thin-walled portion 67. The inclined surface 65 is provided on the surface of the flange portion 54 facing the thrust bearing 23, and is a flat inclined surface having a ring shape so that the inner diameter side is separated from the pressure receiving surface 23B of the thrust bearing 23 as compared with the outer diameter side. ing. The apex 66 is a ring-shaped apex provided at the outer diameter side end of the inclined surface 65. Since the inclined surface 65 is inclined in the radial direction with respect to the pressure receiving surface 23B of the thrust bearing 23, the top portion 66 is in contact with the pressure receiving surface 23B of the thrust bearing 23. The inclined surface 65 may be a curved surface curved in the radial direction.

The thin-walled portion 67 is provided in a ring shape at the connecting portion between the ring main body 53 and the flange portion 54. The thin-walled portion 67 is set so that the thickness of the rotating shaft 14 in the axial direction is thinner than the thickness of the rotating shaft 14 in the flange portion 54 in the axial direction. Therefore, when the thrust load acts on the flange portion 54, the flange portion 42 can be elastically deformed in the axial direction of the rotation shaft 14 with the thin wall portion 67 as a fulcrum with respect to the ring main body 53. Therefore, this thin-walled portion 67 functions as the above-mentioned deformed portion.

Here, the operation of the thrust bearing device 40 described above will be described. 3 and 4 are cross-sectional views showing the operation of the thrust bearing device.

Therefore, when the exhaust turbine supercharger 11 is stopped and the rotation of the rotating shaft 14 is stopped, as shown in FIG. 2, in the thrust bearing device 40, the thrust sleeve 41 is only the top 63 of the flange portion 52. Is in contact with the pressure receiving surface 23A of the thrust bearing 23, and in the thrust ring 42, only the top portion 66 of the flange portion 54 is in contact with the pressure receiving surface 23B of the thrust bearing 23.

Then, when the exhaust turbine supercharger 11 operates, the rotary shaft 14 rotates, and the thrust load F1 acts on one side in the axial direction with respect to the rotary shaft 14, as shown in FIG. 3, the bearing housing 15C is fixed. The rotating shaft 14, the thrust sleeve 41, and the thrust ring 42 move slightly in the same direction with respect to the thrust bearing 23. Then, in the thrust ring 42, the flange portion 54 is deformed in the direction opposite to the thrust load F1 with the thin wall portion 67 as a fulcrum, and a part or all of the inclined surface 65 comes into contact with the pressure receiving surface 23B of the thrust bearing 23. That is, the contact area between the flange portion 54 of the thrust ring 42 and the pressure receiving surface 23B of the thrust bearing 23 increases. That is, since the amount of deformation of the flange portion 54 increases as the thrust load F1 increases, the contact area between the inclined surface 65 and the pressure receiving surface 23B of the thrust bearing 23 increases. Therefore, since the effective bearing area of the thrust bearing 23 increases with the increase of the thrust load F1, the thrust load capacity commensurate with the magnitude of the thrust load F1 is secured.

On the other hand, as shown in FIG. 4, when the thrust load F2 acts on the other side in the axial direction with respect to the rotating shaft 14, the rotating shaft 14 and the thrust sleeve 41 are applied to the fixed thrust bearing 23 of the bearing housing 15C. The thrust ring 42 moves slightly in the same direction. Then, in the thrust sleeve 41, the flange portion 52 is deformed in the direction opposite to the thrust load F2 with the thin wall portion 64 as a fulcrum, and a part or all of the inner peripheral side inclined surface 62 comes into contact with the pressure receiving surface 23A of the thrust bearing 23. .. That is, the contact area between the flange portion 52 of the thrust sleeve 41 and the pressure receiving surface 23A of the thrust bearing 23 increases. That is, since the amount of deformation of the flange portion 52 increases as the thrust load F2 increases, the contact area between the inner peripheral side inclined surface 62 and the pressure receiving surface 23A of the thrust bearing 23 increases. Therefore, since the effective bearing area of the thrust bearing 23 increases with the increase of the thrust load F2, the thrust load capacity commensurate with the magnitude of the thrust load F2 is secured.

In the above description, as shown in FIG. 3, when the thrust load F1 acts on the rotating shaft 14, the flange portion 54 of the thrust ring 42 is deformed by the thrust bearing 23, but the thrust is caused by the urging force of the leaf spring 43. The flange portion 52 of the sleeve 41 is also deformed, but it may or may not come into contact with the pressure receiving surface 23A of the thrust bearing 23. Further, as shown in FIG. 4, when the thrust load F2 acts on the rotating shaft 14, the flange portion 52 of the thrust sleeve 41 is deformed by the thrust bearing 23, but the flange portion 54 of the thrust ring 42 is not deformed. May be good.

FIG. 5 is a graph showing the thrust load with respect to the turbocharger rotation speed. Conventionally, as shown by the solid line in FIG. 5, it is considered that the thrust load increases as the turbocharger rotation speed increases, the increase rate in the low rotation range is high, and the increase rate in the high rotation range is low. It is represented by a curved shape that is convex upward. However, according to the experiment of the applicant, the thrust load with respect to the turbocharger rotation speed is represented by a plurality of black dots, and the increase rate in the low rotation range is low and the increase rate in the high rotation range is high. As shown by the alternate long and short dash line, it became a curved shape with a downward convex shape. Therefore, according to the thrust bearing device 40 of the present embodiment, as described above, the contact area between the flange portions 52 and 54 and the thrust bearing 23 increases as the thrust load increases, so that the supercharger rotation speed The relationship between the thrust load and the thrust load is represented by a one-point chain line in FIG. 5, and the thrust load capacity corresponding to the magnitude of the thrust load can be secured.

As described above, in the thrust bearing device of the first embodiment, the thrust sleeve 41 and the thrust ring 42 fixed to the rotating shaft 14 and the thrust sleeve 41 and the thrust ring 42 are provided with a predetermined gap S4 on the outer peripheral portion thereof. Flange portions 52, 54, a thrust bearing 23 whose outer peripheral portion is supported by the housing 15 and whose inner peripheral portion is arranged in a predetermined gap S4, and flange portions 52, 54 when a thrust load acts on the rotating shaft 14. Is provided with a deformed portion that increases the contact area between the flange portions 52 and 54 and the thrust bearing 23 by being deformed.

Therefore, when a thrust load acts on the rotating shaft 14, the flange portions 52, 54 of the thrust sleeve 41 and the thrust ring 42 are deformed by the deformed portion, so that the contact area between the flange portions 52, 54 and the thrust bearing 23 is reduced. It will increase. That is, the effective bearing area changes according to the fluctuation of the thrust load, and the device can be made compact by adapting the bearing load capacity to the load actually acting on the rotating shaft 14.

In the thrust bearing device of the first embodiment, the inclined surfaces 62 and 65 having a ring shape are provided on the surfaces of the flange portions 52 and 54 of the thrust sleeve 41 and the thrust ring 42 facing the thrust bearing 23. Therefore, by providing the inclined surfaces 62 and 65 on the flange portions 52 and 54, the amount of deformation of the flange portions 52 and 54 increases according to the increase in the thrust load acting on the rotating shaft 14, and the inclined surfaces 62 and 65 become the same. The contact area with the thrust bearing 23 increases, and the effective bearing area can be appropriately changed according to the fluctuation of the thrust load.

In this case, by providing the inclined surfaces 62 and 65 on the flange portions 52 and 54 of the thrust sleeve 41 and the thrust ring 42, the inclined surfaces 62 and 65 can be easily provided without changing the shape of the thrust bearing 23. can. Further, by using the existing thrust sleeve 41 and thrust ring 42, it is possible to prevent an increase in the number of parts and suppress an increase in cost, and the thrust load on one side and the other side of the rotating shaft 14 in the axial direction. Can be dealt with.

In the thrust bearing device of the first embodiment, thin-walled portions 64 and 67 are provided on the thrust sleeve 41 and the thrust ring 42 as deformed portions. Therefore, by using the thin-walled portions 64 and 67 as the deformed portions, the flange portions 52 and 54 can be easily deformed and the contact area with the thrust bearing 23 can be increased when the thrust load is applied to the rotating shaft 14. , The structure can be simplified.

Further, in the booster of the first embodiment, the hollow housing 15, the thrust bearing device 40 mounted on the housing 15, and the rotation rotatably supported by the thrust bearing device 40 on the housing 15. A shaft 14, a turbine 12 provided at one end of the rotary shaft 14 in the axial direction, and a compressor 13 provided at the other end of the rotary shaft 14 in the axial direction are provided.

Therefore, the exhaust gas rotates the turbine 12, and the rotational force is transmitted to the turbine 12 via the rotating shaft 14, and the turbine 12 rotates. At this time, when a thrust load acts on the rotating shaft 14, the flange portions 52, 54 of the thrust sleeve 41 and the thrust ring 42 are deformed by the deformed portion, so that the contact area between the flange portions 52, 54 and the thrust bearing 23 is formed. Will be increased. That is, the effective bearing area changes according to the fluctuation of the thrust load, and the device can be made compact by adapting the bearing load capacity to the load actually acting on the rotating shaft 14.

[Second Embodiment]
FIG. 6 is a cross-sectional view showing the thrust bearing device of the second embodiment. The members having the same functions as those of the above-described embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In the second embodiment, as shown in FIG. 6, the thrust bearing device 70 includes a thrust sleeve (cylinder member) 71, a thrust ring (cylinder member) 72, a thrust bearing 73, and a leaf spring 43. ..

The thrust sleeve 71 is fixed to the outer peripheral portion of the small diameter portion 14B of the rotating shaft 14 so as to be relatively immovable in the circumferential direction and the axial direction. The thrust sleeve 71 is composed of a sleeve body 81 having a cylindrical shape and a flange portion 82 having a disk shape and integrally provided on one side in the axial direction of the sleeve body 81. Further, the thrust ring 72 is fixed to the outer peripheral portion of the small diameter portion 14B of the rotating shaft 14 so as to be relatively immovable in the circumferential direction and the axial direction. The thrust ring 72 is composed of a ring body 83 having a cylindrical shape and a flange portion 84 having a disk shape and integrally provided on one side in the axial direction of the ring body 83. In the thrust sleeve 71 and the thrust ring 72, the sleeve body 81 and the ring body 83 are arranged in series in the axial direction of the rotating shaft 14, and one end of the sleeve body 81 and one end of the ring body 83 are in contact with each other. Further, in the thrust sleeve 71, the other end of the sleeve body 81 is in contact with the back surface 26a of the compressor impeller 26, and in the thrust ring 72, the other end of the ring body 83 is on the end surface of the stepped portion 14C of the rotating shaft 14. It is in contact.

By fixing the thrust sleeve 71 and the thrust ring 72 in series to the outer peripheral portion of the rotating shaft 14, a predetermined gap S4 along the axial direction of the rotating shaft 14 is provided between the flange portions 82 and 84. The thrust bearing 73 has a disk shape in which a through hole 73a through which the rotating shaft 14 penetrates is formed, and pressure receiving surfaces 73A and 73B substantially perpendicular to the axial direction of the rotating shaft 14 are provided on each plane side. The outer peripheral portion of the thrust bearing 73 is fixed to the bearing housing 15C, and the inner peripheral portion is arranged in the predetermined gap S4. The leaf spring 43 has a disk shape having a through hole at the center thereof, the outer peripheral portion thereof is fixed to the bearing housing 15C, and the inner peripheral portion is in contact with the flange portion 82 of the thrust sleeve 71. That is, the leaf spring 43 presses the thrust sleeve 71 toward the thrust ring 72 side via the flange portion 82 by its own urging force.

Then, in the present embodiment, in the thrust bearing device 70 of the second embodiment, when a load is applied to one side in the axial direction of the rotating shaft 14, the thrust bearing 73 is deformed, so that each flange portion 82, A deformed portion is provided to increase the contact area between the 84 and the thrust bearing 73.

The thrust bearing 73 is provided with a pair of deformable flange portions 91, 92 having a disk shape with a deformation gap S5 in the inner peripheral portion in the axial direction of the rotating shaft 14. The first deformable flange portion 91 is provided with a first inclined surface 93, a top portion 94, and a thin-walled portion 95. The first inclined surface 93 is provided on the surface of the first deformed flange portion 91 facing the thrust sleeve 71, and has a ring shape such that the outer diameter side is separated from the facing surface of the flange portion 82 of the thrust sleeve 71 as compared with the inner diameter side. It has a flat slope. The top portion 94 is a ring-shaped apex provided at the inner diameter side end portion of the first inclined surface 93. The top portion 94 is in contact with the thrust sleeve 71 because the first inclined surface 93 is inclined in the radial direction with respect to the thrust sleeve 71.

The thin-walled portion 95 is provided in a ring shape at the branch portion of the first deformable flange portion 91. The thickness of the thin portion 95 in the axial direction of the rotating shaft 14 is set to be thinner than the thickness of the rotating shaft 14 in the thrust bearing 73 in the axial direction. Therefore, in the thrust bearing 73, when a thrust load is applied to the first deformable flange portion 91, the first deformable flange portion 91 can be elastically deformed in the axial direction of the rotating shaft 14 with the thin wall portion 95 as a fulcrum. Therefore, this thin-walled portion 95 functions as the above-mentioned deformed portion. The thin portion 95 is formed thinner than the inner diameter side end portion of the first deformable flange portion 91.

Further, the second deformable flange portion 92 is provided with a second inclined surface 96, a top portion 97, and a thin-walled portion 98. The second inclined surface 96 is provided on the surface of the second deformed flange portion 92 facing the thrust ring 72, and has a ring shape such that the outer diameter side is separated from the facing surface of the flange portion 84 of the thrust ring 72 as compared with the inner diameter side. It has a flat slope. The top portion 97 is a ring-shaped apex provided at the inner diameter side end portion of the second inclined surface 96. The top portion 97 is in contact with the thrust ring 72 because the second inclined surface 96 is inclined in the radial direction with respect to the thrust ring 72.

The thin-walled portion 98 is provided in a ring shape at the branch portion of the second deformable flange portion 92. The thickness of the thin portion 98 in the axial direction of the rotating shaft 14 is set to be thinner than the thickness of the rotating shaft 14 in the thrust bearing 73 in the axial direction. Therefore, in the thrust bearing 73, when a thrust load is applied to the second deformable flange portion 92, the second deformable flange portion 92 can be elastically deformed in the axial direction of the rotating shaft 14 with the thin wall portion 98 as a fulcrum. Therefore, this thin-walled portion 98 functions as the above-mentioned deformed portion. The thin portion 98 is formed thinner than the inner diameter side end portion of the second deformable flange portion 92.

Therefore, when the exhaust turbine supercharger 11 is stopped and the rotation of the rotating shaft 14 is stopped, in the thrust bearing device 70, the thrust bearing 73 has only the tops 94 and 97 of the deformed flange portions 91 and 92. It is in contact with the flange portions 82 and 84 of the thrust sleeve 71 and the thrust ring 72.

Then, when the exhaust turbine supercharger 11 operates, the rotary shaft 14 rotates, and a thrust load acts on one side (left in FIG. 6) in the axial direction with respect to the rotary shaft 14, the bearing housing 15C is fixed. The rotating shaft 14, the thrust sleeve 71, and the thrust ring 72 slightly move in the same direction with respect to the thrust bearing 73. Then, in the thrust bearing 73, the second deformed flange portion 92 is deformed in the same direction as the thrust load with the thin wall portion 98 as a fulcrum, and a part or all of the second inclined surface 96 (pressure receiving surface 73B) comes into contact with the flange portion 84. do. That is, the contact area between the flange portion 84 of the thrust ring 72 and the pressure receiving surface 73B of the thrust bearing 73 increases. That is, since the amount of deformation of the second deformed flange portion 92 increases as the thrust load increases, the contact area between the second inclined surface 96 (pressure receiving surface 73B) and the flange portion 84 increases. Therefore, since the effective bearing area of the thrust bearing 73 increases with respect to the increase in the thrust load, the thrust load capacity corresponding to the magnitude of the thrust load is secured.

On the other hand, when a thrust load acts on the other side in the axial direction (to the right in FIG. 6) with respect to the rotating shaft 14, the rotating shaft 14 and the thrust sleeve 71 are applied to the fixed thrust bearing 73 of the bearing housing 15C. The thrust ring 72 moves slightly in the same direction. Then, in the thrust bearing 73, the first deformed flange portion 91 is deformed in the same direction as the thrust load with the thin wall portion 95 as a fulcrum, and a part or all of the first inclined surface 93 comes into contact with the flange portion 82. That is, the contact area between the flange portion 82 of the thrust sleeve 71 and the pressure receiving surface 23A of the thrust bearing 73 increases. That is, since the amount of deformation of the first deformed flange portion 91 increases as the thrust load increases, the contact area between the first inclined surface 93 (pressure receiving surface 73A) and the flange portion 82 increases. Therefore, since the effective bearing area of the thrust bearing 73 increases with respect to the increase in the thrust load, the thrust load capacity corresponding to the magnitude of the thrust load is secured.

As described above, in the thrust bearing device of the second embodiment, the thrust sleeve 71 and the thrust ring 72 fixed to the rotating shaft 14 and the thrust sleeve 71 and the thrust ring 72 are provided with a predetermined gap S4 on the outer peripheral portion thereof. Each of the flange portions 82 and 84, the thrust bearing 73 whose outer peripheral portion is supported by the housing 15 and whose inner peripheral portion is arranged in the predetermined gap S4, and the thrust bearing 73 are deformed when a thrust load is applied to the rotating shaft 14. By doing so, a deformed portion that increases the contact area between the flange portions 82 and 84 and the thrust bearing 73 is provided.

Therefore, when a thrust load acts on the rotating shaft 14, the thrust bearing 73 is deformed by the deformed portion, so that the contact area between the flange portions 82, 84 and the thrust bearing 73 is increased. That is, the effective bearing area changes according to the fluctuation of the thrust load, and the device can be made compact by adapting the bearing load capacity to the load actually acting on the rotating shaft 14.

In the thrust bearing device of the second embodiment, the inclined surfaces 93 and 96 are provided on the surface of the thrust bearing 73 facing the flange portions 82 and 84. Therefore, it is only necessary to change the shape of the thrust bearing 73, and it is possible to prevent an increase in the number of parts and suppress an increase in manufacturing cost.

In the thrust bearing device of the second embodiment, thin-walled portions 95 and 98 are provided on the inner peripheral portion side of the thrust bearing 73 as a deformed portion. Therefore, by using the thin-walled portions 95 and 98 as the deformed portions, the thrust bearing 73 can be easily deformed and the contact area with the flange portions 82 and 84 can be increased when a thrust load is applied to the rotating shaft 14. , The structure can be simplified.

In the thrust bearing device of the second embodiment, as a deforming portion, a pair of deforming flange portions 91 and 92 are provided with a deformation gap S5 in the inner peripheral portion of the thrust bearing 73. Therefore, by using the deformed flange portions 91 and 92 as the deformed portions, when a thrust load is applied to the rotating shaft 14, the deformed flange portions 91 and 92 are easily deformed to increase the contact area with the flange portions 82 and 84. Can be made to.

[Third Embodiment]
FIG. 7 is a cross-sectional view showing the thrust bearing device of the third embodiment, and FIG. 8 is a graph showing the thrust load with respect to the turbocharger rotation speed. The members having the same functions as those of the above-described embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In the third embodiment, as shown in FIG. 7, the exhaust turbine supercharger 100 is mainly composed of a turbine 12 (see FIG. 1), a compressor 13, and a rotating shaft 14, which are inside the housing 15. Is housed in.

In the compressor 13, the compressor impeller 26 is provided with a flange portion 101 on the outer peripheral portion along the circumferential direction, while the cover member 102 is fixed to the end surface of the bearing housing 15C facing the diffuser 36. The cover member 102 has a disk shape with a through hole formed in the center thereof, an outer peripheral portion thereof is fixed to the bearing housing 15C, and an inner peripheral portion has a predetermined gap with respect to the flange portion 101 of the compressor impeller 26. It is located so as to overlap with each other in the axial direction of the rotating shaft 14. Further, in the bearing housing 15C, a concave portion 103 is formed at a position facing the back surface 26a of the compressor impeller 26, and a convex portion 104 protruding toward the back surface 26a of the compressor impeller 26 is formed.

A ring-shaped pressure adjusting space P2 is provided between the back surface 26a of the compressor impeller 26 and the bearing housing 15C. Further, a first seal gap S11 is provided between the space portion P1 on the discharge port side on the compressed air discharge port 35 (diffuser 36) side of the compressor 13 and the space portion P2 for pressure adjustment. The first seal gap S11 is an axial gap between the flange portion 101 of the compressor impeller 26 and the cover member 102. Further, a second seal gap S12 is provided between the pressure adjusting space portion P2 and the rotation shaft side space portion P3. The rotation shaft side space portion P3 is a space portion in which the thrust sleeve 71 constituting the thrust bearing device is arranged, and the second seal gap S12 is formed between the back surface 26a of the compressor impeller 26 and the convex portion 104 of the bearing housing 15C. Axial gap between them.

Therefore, when the pressure of the space portion P1 on the discharge port side becomes high during the rotation of the compressor 13, the compressor 13 is pressed toward the turbine 12 and a thrust load acts on the rotating shaft 14 toward the turbine 12. Then, the compressor 13 moves to the turbine 12 side due to this thrust load, and the first seal gap S11 becomes larger while the second seal gap S12 becomes smaller. Then, since the volume of the pressure adjusting space P2 decreases and the pressure increases, the pressure for pressing the compressor 13 against the bearing housing 15C increases, and the thrust load toward the compressor 13 with respect to the rotating shaft 14 increases. Works. Then, the compressor 13 moves to the opposite side of the turbine 12 due to this thrust load, and the first seal gap S11 becomes smaller while the second seal gap S12 becomes larger. That is, the size of the first seal gap S11 and the second seal gap S12 fluctuates due to the pressure fluctuation between the discharge port side space portion P1 and the pressure adjusting space portion P2, and the thrust load can be reduced. As a result, the device can be made compact by adapting the load capacity to the load actually acting on the rotating shaft 14.

FIG. 8 is a graph showing the thrust load with respect to the turbocharger rotation speed. Conventionally, as shown by the solid line in FIG. 8, it is considered that the thrust load increases as the turbocharger rotation speed increases, the increase rate in the low rotation range is high, and the increase rate in the high rotation range is low. It is represented by a curved shape that is convex upward. However, according to the experiment of the applicant, the thrust load with respect to the turbocharger rotation speed is represented by a plurality of black dots, and the increase rate in the low rotation range is low and the increase rate in the high rotation range is high. As shown by the alternate long and short dash line, it has a curved shape that is convex upward. Therefore, according to the exhaust turbine turbocharger 100 of the present embodiment, as described above, the thrust load acting on the rotating shaft 14 is reduced by the differential pressure between the discharge port side space portion P1 and the pressure adjusting space portion P2. Therefore, the relationship between the turbocharger rotation speed and the thrust load is represented by a one-point chain line in FIG. 8, and the thrust load capacity corresponding to the magnitude of the thrust load can be secured.

In the supercharger of the third embodiment, the hollow housing 15, the rotating shaft 14 rotatably supported by the housing 15, and the turbine 12 provided at one end of the rotating shaft 14 in the axial direction. , The compressor 13 provided at the other end of the rotating shaft 14 in the axial direction, the pressure adjusting space P2 provided in a ring shape between the back surface 26a of the compressor 13 and the housing 15, and the discharge port of the compressor 13. The first seal gap S11 provided between the side space portion P1 and the pressure adjusting space portion P2 and the second seal gap S12 provided between the pressure adjusting space portion P2 and the rotating shaft side space portion P3 are provided. It is provided.

Therefore, when the pressure in the space portion P1 on the discharge port side becomes high, a thrust load acts on the rotating shaft 14 via the compressor 13 to the turbine 12 side, and the first seal gap S11 becomes larger, while the second seal gap S12 becomes larger. The pressure becomes smaller and the pressure in the pressure adjusting space P2 becomes higher. When the pressure in the pressure adjusting space P2 becomes high, a thrust load on the compressor 13 side acts on the rotating shaft 14 via the compressor 13. As a result, the thrust load can be reduced by the differential pressure between the discharge port side space portion P1 and the pressure adjusting space portion P2, and the load capacity is adapted to the load actually acting on the rotating shaft 14, so that the device is compact. Can be achieved.

11,100 Exhaust turbine supercharger 12 Turbine 13 Compressor 14 Rotating shaft 15 Housing 21,22 Journal bearing 23,73 Thrust bearing 24 Turbine disc 25 Turbine blade 26 Compressor impeller 27 Blade 40,70 Thrust bearing device 41,71 Thrust sleeve 42, 72 Thrust ring 43 Leaf spring 51, 81 Sleeve body 52, 54, 82, 84 Flange part 53, 83 Ring body 61 Outer peripheral side inclined surface 62 Inner peripheral side inclined surface 63, 66, 94, 97 Top 64, 67, 95,98 Thin wall part 65 Inclined surface 91 1st deformed flange part 92 2nd deformed flange part 93 1st inclined surface 96 2nd inclined surface P1 Discharge port side space part P2 Pressure adjustment space part P3 Rotating shaft side space part S11 No. 1 seal gap S12 2nd seal gap

Claims (4)

A hollow housing and
A rotating shaft rotatably supported by the housing,
A turbine provided at one end in the axial direction of the rotating shaft,
A compressor provided at the other end of the rotating shaft in the axial direction,
A pressure adjusting space provided in a ring shape between the back surface side of the compressor and the housing,
A first seal gap provided between the discharge port side space portion of the compressor and the pressure adjusting space portion and increasing when the pressure of the discharge port side space portion becomes higher than the pressure of the pressure adjusting space portion .
A rotation shaft side space portion provided in a ring shape between the back surface side of the compressor and the housing on the inner diameter side of the pressure adjusting space portion.
A second seal gap provided between the pressure adjusting space portion and the rotation shaft side space portion,
Equipped with
The housing is formed with a convex portion protruding toward the back surface side of the compressor, and the second seal gap is an axial gap narrower than the rotation axis side space portion between the back surface of the compressor and the convex portion.
A turbocharger that features that. The supercharger according to claim 1, wherein the housing is provided with a space for pressure adjustment by forming a recess at a position facing the back surface of the compressor. The compressor is provided with a flange portion along the circumferential direction on the outer peripheral portion, while the housing is fixed to the outer peripheral portion of a disk-shaped cover member having a through hole formed in the central portion, and the first seal is provided. The supercharger according to claim 1 or 2, wherein the gap is an axial gap between the outer peripheral portion of the flange portion and the inner peripheral portion of the cover member. The first aspect of the present invention is characterized in that a thrust sleeve is arranged on an outer peripheral portion of the rotating shaft, and the rotating shaft side space portion is a space portion partitioned by the housing, the back surface of the compressor, and the thrust sleeve. The supercharger according to any one of claims 3 .

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