JP2014152634A - Supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve cooling performance with lubricant and thereby suppressing degradation of a seal ring and generation of sludge and oil caulking.SOLUTION: A supercharger comprises: a radial bearing 20; a compartment hole 26a which is formed on a compartment wall section 26 arranged between a bearing hole and a turbine impeller 9 with a turbine shaft penetrated therethrough; a protrusion section 30 which is formed on a portion between the bearing hole of the turbine shaft 8 and the compartment wall section and is protruded in a radial direction of the turbine shaft; and a cooling section 28 which is formed vertically below the compartment hole on the compartment wall section and cools the compartment wall section with lubricant after the same is used for lubricating a bearing section. At least a portion of the cooling section is positioned vertically below an extension line E of a connection line L connecting between a vertically lower edge section 29a of an edge section of the bearing hole at a side of the turbine impeller and the vertically lower edge section of the protrusion section. The lubricant which is used for lubricating the bearing section and spattered from the edge section of the bearing hole at the side of the turbine impeller flows down along the cooling section.

Description

  The present invention relates to a supercharger in which lubricating oil is supplied to a bearing hole.

  2. Description of the Related Art Conventionally, a turbocharger is known in which a turbine shaft having a turbine impeller provided at one end and a compressor impeller provided at the other end is rotatably supported by a bearing housing. Such a supercharger is connected to the engine, the turbine impeller is rotated by exhaust gas discharged from the engine, and the compressor impeller is rotated through the turbine shaft by the rotation of the turbine impeller. Thus, the supercharger compresses air and sends it to the engine as the compressor impeller rotates.

  As shown in Patent Document 1, a partition wall that partitions a space in which a bearing portion is disposed and a space in which a turbine impeller is disposed is formed in the turbocharger, and a turbine shaft is inserted into the partition wall. A partition hole is provided. Lubricating oil is supplied to the bearing portion that supports the turbine shaft of the supercharger. Part of the lubricating oil that lubricated the bearing portion flows out from the turbine impeller side of the bearing portion. A seal ring is arranged so that the lubricating oil that has flowed out does not leak from the partition hole to the turbine impeller side. Lubricating oil that has flowed out from the turbine impeller side of the bearing portion flows down vertically in the space on the bearing portion side from the partition wall portion.

JP-A-1-96429

  Although the above-mentioned lubricating oil also serves as a cooling function for the supercharger main body, there is a limit to the amount of lubricating oil supplied in order to suppress leakage of the lubricating oil. Therefore, in particular, the cooling effect of the portion of the partition wall portion that is vertically below the partition hole is reduced, and depending on the operating conditions, the seal ring is likely to deteriorate, or lubrication is caused by flowing down along the hot partition wall portion. There was a risk that the oil deteriorated and sludge was generated or oil coking was generated.

  An object of the present invention is to provide a supercharger capable of improving the cooling performance by lubricating oil and suppressing the deterioration of the seal ring and the generation of sludge and oil coking.

  In order to solve the above problems, a supercharger according to the present invention includes a supercharger main body, a bearing hole formed in the supercharger main body, a rotatably inserted through the bearing hole, and a turbine impeller at one end. A turbine shaft provided with a compressor impeller at the other end, a bearing portion that is housed in the bearing hole and rotatably supports the turbine shaft, and a lubricating oil passage that supplies lubricating oil to the bearing portion; A partition hole formed in the partition wall portion of the turbocharger main body located between the bearing hole and the turbine impeller and inserted into the partition shaft, and disposed in the partition hole, from the partition hole to the turbine A protrusion that is provided in a portion of the turbine shaft that is located between the bearing hole and the partition wall portion and that suppresses leakage of the lubricating oil to the impeller side and protrudes in the radial direction of the turbine shaft. And the partition wall A cooling portion that is formed vertically below the partition hole and that cools the partition wall portion with lubricating oil after the bearing portion has been lubricated, wherein the cooling portion is at least partially in the bearing hole. It is located vertically below the extension line of the connection that passes through the vertical lower end of the turbine impeller end and the vertically lower end of the protrusion, and lubricates the bearing to lubricate the bearing hole. Lubricating oil scattered from the end portion on the turbine impeller side flows down along the cooling portion.

  The cooling part may be a depression formed in the partition wall part.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to improve the cooling performance by lubricating oil and to suppress the deterioration of a seal ring and the generation of sludge and oil coking.

It is a schematic sectional drawing of a supercharger. It is the elements on larger scale inside the bearing housing of FIG. It is a schematic sectional drawing of the part corresponding to FIG. 2 in a comparative example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a schematic cross-sectional view of the supercharger C. In the following description, the arrow L direction shown in the figure is the left side of the supercharger C, and the arrow R direction is the right side of the supercharger C. As shown in FIG. 1, the supercharger C includes a supercharger main body 1. In the turbocharger main body 1, a bearing housing 2, a turbine housing 4 connected to the left side of the bearing housing 2 by a fastening bolt 3, and a compressor housing 6 connected to the right side of the bearing housing 2 by a fastening bolt 5 are integrated. It is formed.

  The bearing housing 2 is formed with a bearing hole 2a penetrating in the left-right direction of the turbocharger C. The turbine shaft 8 is rotatably supported in the bearing hole 2a, or the thrust acting on the turbine shaft 8 is supported. A bearing member 7 that receives a load is provided. A turbine impeller 9 is integrally fixed to the left end portion of the turbine shaft 8, and this turbine impeller 9 is rotatably accommodated in the turbine housing 4. A compressor impeller 10 is integrally fixed to the right end portion of the turbine shaft 8, and the compressor impeller 10 is rotatably accommodated in the compressor housing 6.

  The compressor housing 6 is formed with an intake port 11 that opens to the right side of the supercharger C and is connected to an air cleaner (not shown). Further, in a state where the bearing housing 2 and the compressor housing 6 are connected by the fastening bolt 5, a diffuser flow path 12 that pressurizes air is formed by the facing surfaces of both the housings 2 and 6. The diffuser passage 12 is formed in an annular shape from the radially inner side to the outer side of the turbine shaft 8 (compressor impeller 10), and communicates with the intake port 11 via the compressor impeller 10 on the radially inner side. ing.

  Further, the compressor housing 6 is provided with an annular compressor scroll passage 13 positioned on the radially outer side of the turbine shaft 8 (compressor impeller 10) with respect to the diffuser passage 12. The compressor scroll flow path 13 communicates with an intake port of an engine (not shown) and also communicates with the diffuser flow path 12. Therefore, when the compressor impeller 10 rotates, air is sucked into the compressor housing 6 from the intake port 11, and the sucked air is accelerated by the action of centrifugal force in the process of flowing between the blades of the compressor impeller 10. Then, the pressure is increased in the diffuser flow path 12 and the compressor scroll flow path 13 and led to the intake port of the engine.

  In the turbine housing 4, an annular turbine scroll passage 14 is formed that is located on the radially outer side of the turbine shaft 8 with respect to the turbine impeller 9. The turbine housing 4 has a discharge port 15 that communicates with the turbine scroll passage 14 via the turbine impeller 9 and faces the front of the turbine impeller 9 and is connected to an exhaust gas purification device (not shown). Yes.

  Further, in a state where the bearing housing 2 and the turbine housing 4 are connected by the fastening bolt 3, a gap 16 is formed between the facing surfaces of both the housings 2 and 4. The gap 16 is a portion in which the variable flow path x through which the exhaust gas flows is formed, and is formed in an annular shape from the radially inner side to the outer side of the turbine shaft 8.

  The turbine scroll passage 14 communicates with a gas inlet (not shown) through which exhaust gas discharged from the engine is guided, and also communicates with the gap 16. Therefore, the exhaust gas led from the gas inlet to the turbine scroll passage 14 is led to the discharge port 15 via the variable passage x and the turbine impeller 9, and the turbine impeller 9 is rotated in the flow process. Become. Then, the rotational force of the turbine impeller 9 is transmitted to the compressor impeller 10 via the turbine shaft 8, and the air is boosted by the rotational force of the compressor impeller 10 as described above, so that the intake port of the engine Will be led to.

  When the flow rate of the exhaust gas guided to the turbine housing 4 changes, the rotation amounts of the turbine impeller 9 and the compressor impeller 10 change, and it becomes impossible to stably guide the sufficiently pressurized air to the intake port of the engine. May end up. Therefore, a variable stationary blade mechanism 17 is provided in the gap 16 of the turbine housing 4 so as to be fixed to the opposing surface of the turbine housing 4 and the bearing housing 2 and to vary the opening degree of communication between the turbine scroll flow path 14 and the discharge port 15. It has been.

  The variable stationary blade mechanism 17 changes the flow rate of the exhaust gas guided to the turbine impeller 9 according to the flow rate of the exhaust gas. Specifically, the variable stationary blade mechanism 17 increases the flow rate of the exhaust gas guided to the turbine impeller 9 by reducing the opening of the variable flow path x when the engine speed is low and the flow rate of the exhaust gas is small. Thus, the turbine impeller 9 can be rotated even with a small flow rate.

  FIG. 2 is a partially enlarged view of the inside of the bearing housing 2 in FIG. Hereinafter, the support structure of the turbine shaft 8 by the bearing member 7 provided in the bearing hole 2a will be described with reference to FIG.

  In the present embodiment, the bearing member 7 includes a radial bearing 20 (bearing portion) and thrust bearings 21 and 22. The radial bearing 20 is made of a so-called semi-floating metal, has an insertion hole 20a that penetrates in the axial direction of the turbine shaft 8, and the turbine shaft 8 is inserted through the insertion hole 20a. Further, the radial bearing 20 is formed with a hole 20b penetrating from the inner peripheral surface (insertion hole 20a) of the radial bearing 20 to the outer peripheral surface.

  The bearing housing 2 is provided with a lubricating oil passage 23 that communicates from the outside of the bearing housing 2 to the bearing hole 2a. The inner peripheral surface of the radial bearing 20 holds an oil film with the turbine shaft 8 by the lubricating oil supplied from the lubricating oil passage 23 and flowing into the hole 20b, and the radial load of the turbine shaft 8 is applied by the oil film pressure. receive.

  The radial bearing 20 is provided with a pin hole 20 e penetrating in a direction perpendicular to the axial direction of the turbine shaft 8. The bearing housing 2 is formed with a screw hole 2b penetrating from the radially outer side to the inner side of the bearing hole 2a and facing the pin hole 20e of the radial bearing 20 accommodated in the bearing hole 2a.

  The pin 24 is partially threaded, is screwed into the screw hole 2 b, and the tip side is inserted into the pin hole 20 e of the radial bearing 20. Thus, the radial bearing 20 is restricted from moving in the axial direction and the rotational direction of the turbine shaft 8 with respect to the bearing hole 2a.

  The thrust bearings 21, 22 are arranged one on each side of the axial direction of the turbine shaft 8 with respect to the thrust collar 25 fixed to the turbine shaft 8, and receive the axial load (thrust load) of the turbine shaft 8.

  The partition wall portion 26 is positioned between the bearing hole 2 a and the turbine impeller 9 in the bearing housing 2, and partitions the space in the bearing housing 2 and the space in the turbine housing 4. A partition hole 26 a through which the turbine shaft 8 is inserted is formed in the partition wall portion 26.

  Lubricating oil that lubricates the radial bearing 20 and is discharged to the turbine impeller 9 side of the bearing hole 2a is scattered in the space between the bearing hole 2a and the partition wall portion 26, and the inner wall of the bearing housing 2 such as the partition wall portion 26. Then, the oil flows down the oil drain passage 2c formed vertically below the bearing hole 2a.

  At this time, a seal portion 27 is provided inside the partition hole 26a in order to prevent the lubricant from reaching the partition hole 26a and leaking out of the lubricant toward the turbine impeller 9 from the partition hole 26a. The seal portion 27 is configured by a seal ring, blocks a gap between the partition hole 26a and the turbine shaft 8, and suppresses leakage of lubricating oil from the partition hole 26a to the turbine impeller 9 side.

  By the way, the turbine impeller 9 side of the bearing housing 2 is likely to be hotter than the compressor impeller 10 side due to heat transfer from the high-temperature exhaust gas. In particular, in the bearing housing 2, there is an actual situation that the vertically lower part of the seal portion 27 is difficult to be cooled, and the deterioration of the seal portion 27 easily proceeds at a high temperature. Therefore, in this embodiment, a cooling unit 28 is provided on the partition wall 26.

  FIG. 3 is a schematic cross-sectional view of a portion corresponding to FIG. 2 in the comparative example. As shown in FIG. 3, in the comparative example, a portion of the partition wall portion B that is positioned vertically below the partition hole Ba is a flat wall surface.

  On the other hand, in the present embodiment, as shown in FIG. 2, the cooling unit 28 is provided in the partition wall portion 26 vertically below the partition hole 26 a. The cooling portion 28 is a recess formed in the partition wall portion 26 and is a portion that is depressed toward the turbine impeller 9 side. Here, the cooling unit 28 is a curved surface.

  By providing the cooling part 28, the surface area of the partition wall part 26 located vertically lower than the partition hole 26a is larger than that of the comparative example. Therefore, the distance and time that the lubricating oil after lubricating the bearing member 7 flows over the surface can be increased, and the cooling effect of the partition wall portion 26 can be increased.

  Further, at the end 29 of the bearing hole 2a on the turbine impeller 9 side, a large-diameter hole 2d having a diameter larger than the portion of the bearing hole 2a where the radial bearing 20 is disposed is adjacent to the axial direction of the turbine shaft 8. Is provided. The large-diameter hole 2d is open vertically below, and the lubricating oil after lubricating the radial bearing 20 flows out from the end 29 toward the oil discharge passage 2c.

  The protruding portion 30 is an annular flange portion that is provided in a portion of the turbine shaft 8 that is located between the bearing hole 2 a and the partition wall portion 26 and protrudes in the radial direction of the turbine shaft 8. The projecting portion 30 is opposed to a portion on the turbine impeller 9 side in the radial direction on the wall surface forming the large-diameter hole 2d, and since the radial gap is small, it is from other than the opening portion of the large-diameter hole 2d. Lubricating oil is difficult to flow out. Moreover, the protrusion part 30 maintains the dimensional relationship which protrudes on the connection which connects the periphery of the edge part 29 of the bearing hole 2a, and the periphery of the division hole 26a. As a result, the lubricating oil ejected from the end 29 does not directly enter the partition hole 26a.

  In contrast, the cooling unit 28 includes a vertical lower end portion 29a of the end portion 29 on the turbine impeller 9 side in the bearing hole 2a and a vertically lower end of the projecting portion 30 (more specifically, vertically below the projecting portion 30). In addition, it is positioned vertically lower than the extension line E of the connection line L that passes through the end portion 30a that is the end of the compressor impeller 10 side.

  Therefore, after the bearing member 7 is lubricated and guided to the end 29 on the turbine impeller 9 side of the bearing hole 2a, the lubricating oil scattered to the lower left side in FIG. It flows down along the cooling part 28 located vertically downward.

  That is, by providing the cooling portion 28 vertically below the extension line E, a part of the lubricating oil that lubricates the bearing member 7 and is ejected from the end portion 29 of the bearing hole 2a can reach the cooling portion 28. The cooling effect by the part 28 can be further enhanced.

  Therefore, the cooling performance by the lubricating oil is improved by the cooling section 28, and it is possible to suppress the deterioration of the seal section 27 and the generation of sludge and oil coking.

  In the above-described embodiment, the case where the depressions that constitute the cooling unit 28 are formed on a curved surface has been described, but the shape of the cooling unit is not limited to a curved surface, and may be a rectangular cross-section combining planes, The shape may be a combination of a curved surface and a flat surface. In any case, by setting the cooling portion 28 as a depression, it becomes possible to increase the oil drainage by enlarging the flow path of the lubricating oil regardless of the specific shape of the depression. Furthermore, the cooling unit 28 is not limited to the depression as long as the surface area can be increased, and may be, for example, unevenness.

  Further, FIG. 2 shows a configuration in which the whole cooling unit 28 is positioned vertically below the extension line E of the connection L. However, at least a part of the cooling unit 28 only needs to be positioned vertically below the extension line E of the connection L.

  2 shows a configuration in which the radial tip shape of the protrusion 30 is parallel to the turbine shaft 8, the tip shape of the protrusion 30 may be parallel to the connection line L. Further, by making the outer diameter of the protruding portion 30 smaller than the inner diameter of the partition hole 26a, the assembly of the turbine shaft 8 to the bearing housing 2 is facilitated.

  In the above-described embodiment, the bearing member 7 is described as being configured by the radial bearing 20 and the thrust bearings 21 and 22. However, the thrust bearings 21 and 22 are not provided, and the bearing member 7 is configured only by the radial bearing 20. Also good.

  Moreover, although the radial bearing 20 demonstrated the case where it comprised with a semi-floating metal in embodiment mentioned above, a radial bearing may be comprised with a full floating metal.

  In the above-described embodiment, the vertical direction indicates that the supercharger C is in gravity with respect to the supercharger C in this posture, assuming a posture when the supercharger C is mounted on, for example, a vehicle placed on a horizontal plane. 1 to 3 and is the lower side in the figure.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  The present invention can be used for a supercharger in which lubricating oil is supplied to a bearing hole.

C ... supercharger E ... extension line L ... connection 1 ... supercharger body 2a ... bearing hole 8 ... turbine shaft 9 ... turbine impeller 10 ... compressor impeller 20 ... radial bearing (bearing portion)
23 ... Lubricating oil passage 26 ... Partition wall part 26a ... Partition hole 27 ... Seal part 28 ... Cooling part 29 ... End part 29a ... Vertical lower end part 30 ... Projection part 30a ... End part

Claims (2)

A turbocharger body;
A bearing hole formed in the supercharger body;
A turbine shaft rotatably inserted into the bearing hole, provided with a turbine impeller at one end and a compressor impeller at the other end;
A bearing portion housed in the bearing hole and rotatably supporting the turbine shaft;
A lubricating oil passage for supplying lubricating oil to the bearing portion;
A partition hole formed in a partition wall portion of the turbocharger body located between the bearing hole and the turbine impeller, and through which the turbine shaft is inserted;
A seal portion that is disposed in the partition hole and suppresses leakage of the lubricating oil from the partition hole to the turbine impeller side;
A projecting portion provided in a portion of the turbine shaft located between the bearing hole and the partition wall portion and projecting in a radial direction of the turbine shaft;
A cooling section that is formed vertically below the partition hole of the partition wall section, and cools the partition wall section with lubricating oil after lubricating the bearing section;
With
The cooling part is
At least a part of the bearing hole is positioned vertically below the extension line of the connection that passes through the vertical lower end of the turbine impeller side end of the bearing hole and the vertically lower end of the protrusion,
The supercharger characterized in that the lubricating oil that has lubricated the bearing portion and scattered from the end portion of the bearing hole on the turbine impeller side flows down along the cooling portion.   The supercharger according to claim 1, wherein the cooling part is a depression formed in the partition wall part.

Images