JP2007224900A - Supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supercharger capable of further changing the sealing performance of an oil seal structure, while further improving workability when installing a seal member. <P>SOLUTION: The oil seal structure of the supercharger 10 has an oil draining member 21, a seal housing 25 and the annular seal member 23 arranged between the oil draining member 21 and the seal housing 25. The oil draining member 21 has an outer-edge formed part of a substantially circular shape in a vertical cross section with respect to the axial direction in a compressor side tip. The oil draining member 21 also has an outer-edge diametrically contracted part 21a formed at its compressor side tip and making a radius of the outer edge smaller than the other part of an outer edge. The seal member 23 is fitted to the outer-edge diametrically contracted part 21a. The seal housing 25 is formed with an opening for passing the oil draining member 21, and the seal housing 25 also contacts with the seal member 23 at the inner edge in the radial direction wherein the opening is formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a supercharger.

  The turbocharger includes a turbine and a compressor as its basic configuration, the turbine has a turbine impeller that is rotationally driven by engine exhaust gas, and the compressor has a compressor impeller that is rotationally driven by the rotation of the turbine impeller. ing. Further, in order to transmit the rotational driving force from the turbine to the compressor, the turbocharger is provided with a rotating shaft that connects the turbine impeller and the compressor.

  With such a configuration, the turbine impeller is rotated by the exhaust gas of the engine, and at the same time, the compressor impeller is also rotationally driven, and compressed air is supplied from the compressor to the engine. As a result, the engine is brought into a supercharged state that is higher than that of natural intake, and the engine is put into a high output state.

  In order to rotatably support the rotating shaft, a bearing structure is incorporated inside the turbocharger housing, and the lubricant supplied to the bearing structure leaks to the compressor side of the bearing structure on the compressor side. An oil seal structure is incorporated to prevent this.

Such a bearing structure and an oil seal structure are disclosed in Patent Document 1, for example.
FIG. 7 is a longitudinal sectional view showing the overall configuration of the supercharger of Patent Document 1, and FIG. 8 is a partially enlarged view of FIG. 7 showing a bearing structure and an oil seal structure.

As shown in FIG. 8, this bearing structure includes a thrust bush 33 fixed to the rotating shaft 31, a positive thrust bearing 37 positioned on the compressor side of the thrust bush 33 and fixed to the bearing housing 35, and a thrust. And an anti-thrust bearing 39 which is located on the turbine side of the bush 33 and is fixed to the bearing housing 35. The bearing structure has journal bearings 41 provided on the turbine side and the compressor side, respectively.
The positive thrust bearing 37 and the anti-thrust bearing 39 receive an axial load from the rotating shaft 31 via the thrust bush 33, and the journal bearing 41 receives a radial load from the rotating shaft 31.

In order to supply lubricating oil to the bearing structure described above, an oil passage 43 is formed in the housing, and a dedicated oil passage 45 that communicates with the oil passage 43 and opens only on the pad surface is formed in the positive thrust bearing 37. Has been.
In order to prevent the lubricating oil supplied to the pad surface through the oil passage 43 and the dedicated oil passage 45 from leaking to the compressor side, an oil seal structure is provided on the compressor side of the bearing structure.

This oil seal structure has an oil draining member 47 fitted to the rotary shaft 31 on the compressor side of the positive thrust bearing 37.
In the oil draining member 47, a flange portion 47a is formed at the end portion on the turbine side, and one ring groove 47b is formed in the circumferential direction on the outer peripheral surface on the compressor side. An annular seal member 49 is fitted in the ring groove 47b. The seal member 49 is made of, for example, metal.

The oil seal structure further includes an oil defender plate 51 fixed to the housing on the turbine side of the positive thrust bearing 37.
The oil defender plate 51 is, for example, a disk-shaped thin plate, and has a shape in which a lower portion is bent up toward the turbine side, and guides the lubricating oil after lubricating the normal thrust bearing 37 to the oil discharge port 55.

Further, the oil seal structure has a seal housing 53 fixed to the housing 35 on the compressor side of the all-defense plate 51. The seal housing 53 extends from the outside in the radial direction to the inside in the radial direction to a position where it comes into contact with the seal member 49, and is in contact with the seal member 49 described above in the circumferential direction.
This prevents the lubricating oil from leaking from the seal housing 53 to the compressor side.
Japanese Utility Model Publication No. 4-119624 "Turbocharger bearing structure"

In the oil seal structure of Patent Document 1, since the seal member 49 is annular, in order to attach it to the ring groove 47b, it must be fitted into the ring groove 47b from the outside in the radial direction. In addition, it is necessary to attach the seal member 49 before the seal housing 53 is incorporated into the supercharger, and the seal member 49 cannot be attached later, which is inconvenient.
Thus, in patent document 1, workability | operativity at the time of attachment of the sealing member 49 is bad.
Further, a structure with higher sealing performance than the oil seal structure of Patent Document 1 is desired.

  Accordingly, an object of the present invention is to provide a supercharger that can further improve the workability at the time of attaching a seal member and further enhance the sealability of the oil seal structure.

  To achieve the above object, according to the present invention, a turbine impeller that is rotationally driven by exhaust gas, a compressor impeller that is rotationally driven by the rotation of the turbine impeller, and compresses air, and a rotation that connects the turbine impeller and the compressor impeller And a housing in which a bearing structure that rotatably supports the rotating shaft is incorporated, and the lubricating oil supplied to the bearing structure leaks to the compressor side on the compressor side of the bearing structure An oil seal structure in which an oil seal structure is incorporated, wherein the oil seal structure includes an oil drain member fixed to the rotating shaft, and an oil drain member on a radially outer side of the oil drain member. A seal housing fixed to the housing so as to surround, and disposed between the oil draining member and the seal housing. The oil draining member has a portion where a substantially circular outer edge is formed in the cross section perpendicular to the axial direction at the tip end portion on the compressor side. The member has an outer edge reduced diameter portion which is formed at the compressor side tip and has a radius of the outer edge smaller than other portions of the outer edge, and the seal member is fitted to the outer edge reduced diameter portion, In the seal housing, an opening through which the oil draining member passes is formed at the center of a cross section perpendicular to the axial direction, and further, the seal housing is formed at the radial inner edge forming the opening. A turbocharger characterized in that the lubricant is prevented from leaking to the compressor side by contacting with the seal member.

Since the turbocharger is configured so that the seal member is fitted to the outer edge reduced diameter portion formed at the compressor side tip of the oil draining member, the turbocharger is axially moved from the compressor side when the turbocharger is assembled. It is possible to fit the outer edge reduced diameter portion of the oil draining member simply by moving the seal member. Further, since the seal member can be attached only by moving the seal member in the axial direction, the seal member can be attached even after the seal housing is assembled.
Therefore, in the supercharger, the attaching operation of the seal member can be further simplified than before.

  According to a preferred embodiment of the present invention, the oil draining member has an outer edge enlarged diameter portion which is coupled to the outer edge reduced diameter portion in the axial direction from the turbine side and has a radius of the outer edge larger than that of the outer edge reduced diameter portion.

  Thus, since the oil draining member has the outer edge enlarged diameter portion that is axially coupled to the outer edge reduced diameter portion from the turbine side, a step between the outer edge reduced diameter portion and the outer edge enlarged diameter portion is formed. With this step, the seal member fitted to the outer edge reduced diameter portion can be positioned in the axial direction.

  According to an embodiment of the present invention, in order to achieve the above object, in the supercharger, the seal housing is formed at an end on the compressor side, and an inner edge having a radius of the inner edge larger than other portions of the inner edge. An enlarged diameter portion, and an inner edge reduced diameter portion that is axially coupled to the inner edge enlarged diameter portion from the turbine side and has a radius of the inner edge smaller than that of the inner edge enlarged diameter portion. The outer edge has a radius larger than the radius of the inner edge of the inner edge reduced diameter portion, and is in contact with the inner edge of the inner edge enlarged diameter portion.

In this configuration, the radially outer edge of the seal member has a radius larger than the radius of the inner edge of the inner edge reduced diameter portion of the seal housing and is in contact with the inner edge of the inner edge enlarged portion of the seal housing. The lubricating oil that has flowed axially toward the compressor side through the gap between the inner edge reduced diameter portion and the portion on the turbine side of the oil removing member that is closer to the turbine than the outer edge reduced diameter portion (for example, the outer edge enlarged diameter portion) Thus, the sealing member is surely blocked by the seal member extending in the direction perpendicular to the axial direction so as to close the gap. Moreover, in the said structure, since there exists an inner edge reduced diameter part of a seal housing, the clearance gap which causes lubricating oil to leak becomes narrow, and lubricating oil becomes difficult to leak.
Therefore, the lubricating oil flowing from the bearing structure to the compressor side can be more reliably blocked, and the sealing performance of the lubricating oil to the compressor side can be further enhanced than before.

  According to a preferred embodiment of the present invention, the oil seal structure has a holding member that holds the seal member in a fixed position.

  With this holding member, the seal member can be held at a fixed position.

  According to a preferred embodiment of the present invention, in the supercharger, the oil seal structure includes a holding member that holds the seal member in a fixed position, and a turbine side end surface of the holding member is a compressor side of the seal member. By contacting the end surface, the seal member is held between the turbine side end surface and the outer edge enlarged diameter portion of the oil draining member.

  With this configuration, the seal member fitted to the outer edge reduced diameter portion of the oil draining member can be reliably held between the turbine side end surface of the holding member and the outer edge enlarged diameter portion of the oil draining member. Moreover, it becomes difficult to leak lubricating oil by making the outer diameter of a holding member larger than the outer edge enlarged diameter part of an oil draining member. Further, by overlapping the axial position of the inner edge enlarged diameter portion of the seal housing and the axial position of the holding member outer diameter, it is possible to reduce the gap formed between the inner edge enlarged diameter portion and the holding member. As a result, the lubricating oil is difficult to leak.

  According to a preferred embodiment of the present invention, the holding member is the compressor impeller.

  Since the compressor impeller is used as the holding member, the seal member can be held at a fixed position without providing a new member.

  According to a preferred embodiment of the present invention, the holding member is provided between the compressor impeller and the seal member.

  Thus, by providing the holding member between the compressor impeller and the seal member, the seal member can be held at a fixed position.

  According to a preferred embodiment of the present invention, the holding member is a sleeve provided between the compressor impeller and the seal member.

  Thus, the seal member can be held at a fixed position by providing the sleeve between the compressor impeller and the seal member.

  According to another embodiment of the present invention, an electric motor for assisting the rotation of the rotating shaft is further provided, and a rotor of the electric motor is disposed between the compressor impeller and the seal member as the holding member.

  Thus, the sealing member can be held at a fixed position by arranging the rotor of the electric motor as a holding member between the compressor impeller and the sealing member.

As described above, according to the present invention, the seal member is configured to be fitted to the outer edge reduced diameter portion formed at the compressor-side tip of the oil draining member. By simply moving the seal member in the direction, it can be fitted to the outer edge reduced diameter portion of the oil draining member, and the attaching operation of the seal member can be further simplified as compared with the conventional case.
Further, in the present invention, the radial outer edge of the seal member has a radius larger than the radius of the inner edge of the inner edge reduced diameter portion of the seal housing and is in contact with the inner edge of the inner edge enlarged diameter portion of the seal housing. The lubricating oil that has flowed to the compressor side in the axial direction through the gap between the inner edge reduced diameter portion of the housing and the outer edge enlarged diameter portion of the oil removing member extends in a direction perpendicular to the axial direction so as to close the gap. The seal member is surely obstructed. Therefore, the lubricating oil flowing from the bearing structure to the compressor side can be more reliably blocked, and the sealing performance of the lubricating oil to the compressor side can be further enhanced than before.

  A preferred embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a longitudinal sectional view in which a supercharger according to an embodiment of the present invention is cut in the axial direction, and shows the overall configuration of the supercharger. As shown in FIG. 1, a supercharger 10 according to this embodiment includes a turbine impeller 1 that is rotationally driven by exhaust gas, a compressor impeller 3 that is rotationally driven by the rotation of the turbine impeller 1 and compresses air, and the turbine impeller 1. And a compressor shaft 3 and a housing 7 in which a bearing structure for rotatably supporting the rotating shaft 5 is incorporated.

  In the example of FIG. 1, the housing 7 is a bearing housing that is separated from the turbine housing 8 that houses the turbine impeller 1 and the compressor housing 9 that houses the compressor impeller 3. However, according to the present invention, the housing that houses the bearing structure may be a housing that is formed integrally with at least one of the turbine housing and the compressor housing.

  As shown in FIG. 1, the bearing structure includes a thrust bush 11 fixed to the rotary shaft 5, a positive thrust bearing 13 positioned on the compressor side of the thrust bush 11 and fixed to the bearing housing 7, and a thrust bush. 11 and the anti-thrust bearing 15 which is located on the turbine side and is fixed to the bearing housing 7. Further, the bearing structure has journal bearings 17 provided on the turbine side and the compressor side, respectively. The roles of these bearings are the same as in the conventional case described above with reference to FIGS.

In order to supply lubricating oil to the above-described bearing structure, an oil passage 19 is formed in the housing 7, and a dedicated oil passage 20 that communicates with the oil passage 19 and opens in the pad surface is formed in the positive thrust bearing 13. ing.
An oil seal structure is incorporated on the compressor side of the bearing structure so that the lubricating oil supplied to the pad surface through the oil path 19 and the dedicated oil path 20 does not leak to the compressor side.

  As shown in FIG. 2, this oil seal structure is fixed to the housing 7 so as to surround the oil draining member 21 fixed to the rotating shaft 5 and the oil draining member 21 on the radially outer side of the oil draining member 21. A seal housing 25, and an annular seal member 23 disposed between the oil draining member 21 and the seal housing 25. Note that the outer edge of the cross section perpendicular to the axial direction of the oil draining member 21 may not be partially circular with respect to the axial direction as long as the rotation of the rotating shaft 5 is not adversely affected. Moreover, the sealing member 23 is formed, for example with the metal.

The oil draining member 21 has portions 21a and 21b formed with a substantially circular outer edge in a cross section perpendicular to the axial direction at the compressor side tip.
In particular, according to the present embodiment, the oil draining member 21 has an outer edge reduced diameter portion 21a formed at the compressor-side tip and having a radially outer edge radius smaller than other portions of the outer edge.
The seal member 23 is fitted to the outer edge reduced diameter portion 21a at the compressor-side tip of the oil draining member 21.

The assembly of the supercharger 10 having the above-described configuration will be described with reference to FIGS. 1 and 2. Each member of the supercharger 10 can be incorporated in the bearing housing 7 in the following order (1) to (10).
(1) The journal bearing 17 is inserted into the bearing housing 7 from the compressor side and attached to the bearing housing 7.
(2) The rotary shaft 5 integrated with the turbine impeller 1 is inserted into the journal bearing 17 attached to the bearing housing 7 from the turbine side.
(3) The anti-thrust bearing 15 is passed through the rotary shaft 5 from the compressor side and fixed to the bearing housing 7.
(4) The thrust bush 11 is attached to the rotating shaft 5 through the rotating shaft 5 from the compressor side.
(5) The positive thrust bearing 13 is passed through the rotary shaft 5 from the compressor side and fixed to the bearing housing 7.
(6) The oil draining member 21 is attached to the rotating shaft 5 through the rotating shaft 5 from the compressor side.
(7) The seal housing 25 is fixed to the bearing housing 7 through the rotary shaft 5 from the compressor side.
(8) The seal member 23 is passed through the rotary shaft 5 from the compressor side and fitted into the outer edge reduced diameter portion 21 a of the oil draining member 21.
(9) The compressor impeller 3 is attached to the rotary shaft 5 through the rotary shaft 5 from the compressor side.
(10) A nut 24 is attached to the rotary shaft 5 from the compressor side, and the thrust bush 11, the oil draining member 21, and the compressor impeller 3 are fastened and fixed to the rotary shaft 5 with the nut 24.

Thus, since the supercharger 10 can be assembled, it is formed at the front end of the oil draining member 21 on the compressor side simply by moving the seal member 23 in the axial direction from the compressor side when the supercharger 10 is assembled. It can be attached to the oil draining member 21 so that the seal member 23 is fitted to the outer edge reduced diameter portion 21a.
Therefore, the attaching operation of the seal member 23 can be further simplified as compared with the conventional case.

  Further, the outer edge reduced diameter portion 21a is formed by shoulder processing by scraping off the corner of the outer edge of the oil draining member 21 on the compressor side, and the seal member 23 is attached to the outer edge reduced diameter portion 21a. Therefore, unlike the conventional example of FIG. 4, it is not necessary to perform groove processing for forming a groove in the intermediate portion of the oil draining member 21, and shoulder processing that is simpler than groove processing is sufficient. Therefore, the processing of the mounting portion of the seal member 23 is easier than before.

  Preferably, the oil draining member 21 has an outer edge enlarged diameter portion 21b that is coupled to the outer edge reduced diameter portion 21a in the axial direction from the turbine side and has a larger outer edge radius than the outer edge reduced diameter portion 21a.

  Thus, since the oil draining member 21 has the outer edge enlarged diameter portion 21b that is axially coupled to the outer edge reduced diameter portion 21a from the turbine side, a step between the outer edge reduced diameter portion 21a and the outer edge enlarged diameter portion 21b is formed. The With this step, the seal member 23 fitted in the outer edge reduced diameter portion 21a can be positioned in the axial direction. That is, the seal member 23 fitted to the outer edge reduced diameter portion 21 a is positioned in the axial direction by contacting the outer edge enlarged diameter portion 21 b of the oil draining member 21 from the axial direction.

In the example of FIG. 2, the oil draining member 21 and the positive thrust bearing 13 are separated and used as separate members. However, the oil draining member 21 and the thrust bush 11 may be integrally formed. In this case, the number of parts is reduced and the configuration is simplified.
The other structure of the oil draining member 21 may be the same as that of the conventional example of FIG.

On the other hand, the seal housing 25 fixed to the housing 7 is formed with an opening through which the oil draining member 21 passes at the center of the cross section perpendicular to the axial direction. The opening may be substantially circular at the compressor side tip.
The seal housing 25 prevents the lubricating oil from leaking to the compressor side by contacting the seal member 23 in the circumferential direction at the radial inner edge forming the opening.
The seal housing 25 includes an inner edge enlarged portion 25a formed at the compressor-side tip and having a radius of the inner edge in the radial direction larger than other portions of the inner edge, and the inner edge enlarged portion 25a from the turbine side and the axial direction. And an inner edge reduced diameter portion 25b having a radius of the inner edge smaller than that of the inner edge enlarged diameter portion 25a.

In particular, according to the present embodiment, the outer edge in the radial direction of the seal member 23 has a radius larger than the radius of the inner edge of the inner edge reduced diameter portion 25b, and is in contact with the inner edge of the inner edge enlarged diameter portion 25a in the circumferential direction.
In other words, the lubricating oil flows axially toward the compressor through the gap between the inner edge reduced diameter portion 25b of the seal housing 25 and the outer edge enlarged diameter portion 21b of the oil draining member 21, but the seal member 23 It extends in a direction perpendicular to the axial direction so as to close the gap. Therefore, the lubricating oil that has flowed to the compressor side through this gap is reliably blocked by the seal member 23, so that the sealing performance of the lubricating oil to the compressor side can be further enhanced. Further, the inner edge reduced diameter portion 25b of the seal housing 25 can narrow a gap formed between the inner edge reduced diameter portion 25b and the outer edge enlarged diameter portion 21b. Oil does not leak easily.

Further, according to the present embodiment, the turbine-side end surface 3 a of the compressor impeller 3 is in contact with the compressor-side end surface 23 a of the seal member 23, whereby the seal member 23 is expanded to the outer edge of the turbine-side end surface 3 a and the oil draining member 21. It is sandwiched and held between the diameter portion 21b.
Thus, according to the present embodiment, the seal member 23 can be held using the turbine-side end surface 3a of the existing compressor impeller without preparing a new member. Therefore, even if the compressor-side tip of the oil draining member 21 is formed as the outer edge reduced diameter portion 21a that is the attachment location of the seal member 23, the seal member 23 is reliably secured using the turbine-side end surface 3a of the existing compressor impeller 3. Can be held in.

  2, the turbine side end surface 3a of the compressor impeller 3 and the compressor side end surface 21c of the oil draining member 21 both extend in the direction perpendicular to the axial direction, and are mutually in the axial direction. In contact. Thereby, the seal member 23 can be stably held.

Thus, although the compressor impeller 3 functions as a holding member that holds the seal member 23 at a fixed position, another member may be provided in the supercharger as a holding member.
Preferably, the holding member is provided between the compressor impeller 3 and the seal member 23.

For example, the holding member is a cylindrical sleeve provided between the compressor impeller 3 and the seal member 23.
FIG. 3 is a longitudinal sectional view showing the supercharger 10 ′ when the sleeve 26 is provided, and FIG. 4 is a partially enlarged view of FIG. 3 showing the configuration in the vicinity of the seal member 23.
As shown in FIG. 4, the turbine-side end surface 26 a of the sleeve 26 is in contact with the compressor-side end surface 23 a of the seal member 23, whereby the seal member 23 is connected to the turbine-side end surface 26 a of the sleeve 26 and the outer edge of the oil draining member 21. It can be sandwiched and held between the enlarged diameter portion 21b.
Moreover, you may employ | adopt the following structure so that lubricating oil may become difficult to leak. By making the outer diameter of the holding member 26 larger than the outer edge enlarged portion 21b of the oil draining member 21, in other words, the radial outer edge of the holding member 26 is more radial than the position of the radially outer edge of the outer edge enlarged portion 21b. By positioning it outside, the path through which the lubricating oil may pass becomes complicated, and the lubricating oil is difficult to leak. Further, by overlapping the axial position of the inner edge enlarged diameter portion 25 a of the seal housing 25 and the axial position of the outer diameter of the holding member 26, in other words, the compressor side tip of the inner edge enlarged diameter portion 25 a is connected to the holding member 26. By causing the inner edge enlarged diameter portion 25a and the radial outer edge of the holding member 26 to overlap each other in the axial direction closer to the compressor than the turbine side tip of the radially outer edge, a gap (this is a cause of lubricating oil leakage) In this case, the gap between the radially inner edge of the inner edge enlarged diameter portion 25a and the radially outer edge of the holding member 26 can be reduced. As a result, the lubricating oil is difficult to leak.
4, the turbine side end surface 26a of the sleeve 26 and the compressor side end surface 21c of the oil draining member 21 both extend in the direction perpendicular to the axial direction, and are in contact with each other in the axial direction. is doing. Thereby, the seal member 23 can be stably held.
Other configurations of the supercharger 10 ′ in FIGS. 3 and 4 are the same as those in FIGS.

When the supercharger further includes an electric motor that assists the rotation of the rotary shaft 5, the rotor of this electric motor may be used as a holding member and disposed between the compressor impeller 3 and the seal member 23.
FIG. 5 is a longitudinal sectional view showing the supercharger 10 ″ when the electric motor 27 is incorporated, and FIG. 6 is a partial enlarged view of FIG.
The electric motor 27 includes a rotor 28 fixed to the rotary shaft 5 and a stator 29 provided on the radially outer side of the rotor 28. The rotor 28 includes a plurality of permanent magnets arranged in the circumferential direction, and the stator 29 includes a plurality of coils arranged in the circumferential direction. Electric power is supplied from the outside of the supercharger 10 ″ to the stator 29 through a power supply line (not shown) to assist the rotation of the rotary shaft 5.
As shown in FIG. 6, the turbine-side end surface 28 a of the rotor 28 is in contact with the compressor-side end surface 23 a of the seal member 23, whereby the seal member 23 is connected to the turbine-side end surface 28 a of the rotor 28 and the outer edge of the oil draining member 21. It can be sandwiched and held between the enlarged diameter portion 21b.
6, the turbine side end surface 28a of the rotor 28 and the compressor side end surface 21c of the oil draining member 21 both extend in a direction perpendicular to the axial direction, and contact each other in the axial direction. is doing. Thereby, the seal member 23 can be stably held.
Other configurations of the supercharger 10 ″ in FIGS. 5 and 6 are the same as those in FIGS. 5 and 6, the bearing housing 7 is formed by joining the divided members as shown by a broken line A.

As described above, in the supercharger according to the above-described embodiment, the seal member is fitted to the outer edge reduced diameter portion formed at the compressor-side tip of the oil draining member. The oil draining member can be attached only by moving the seal member in the axial direction from the side, and the attaching operation of the seal member can be further simplified as compared with the conventional art.
Further, in the supercharger according to the above-described embodiment, the lubricating oil that has flowed in the axial direction through the gap between the inner edge reduced diameter portion of the seal housing and the outer edge enlarged diameter portion of the oil draining member passes through this gap. It is configured to be blocked by a seal member extending in a direction perpendicular to the axial direction so as to close. Therefore, the lubricating oil flowing from the bearing structure to the compressor side can be more reliably blocked, and the sealing performance of the lubricating oil to the compressor side can be further enhanced than before.

  In addition, this invention is not limited to embodiment mentioned above, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

It is a figure showing the whole turbocharger composition by the embodiment of the present invention. FIG. 2 is a partially enlarged view of FIG. 1 showing an oil seal structure according to an embodiment of the present invention. It is a figure which shows the whole structure of the supercharger which provided the sleeve as a holding member of a sealing member. It is the elements on larger scale of FIG. 3 which shows the structure of a seal member vicinity. It is a figure which shows the whole structure of the supercharger using the rotor of the electric motor as a holding member. It is the elements on larger scale of FIG. 5 which shows the structure of a seal member vicinity. It is a figure which shows the whole supercharger structure. It is the elements on larger scale of FIG. 7, and has shown the conventional bearing structure and oil seal structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Turbine impeller 3 Compressor impeller 3a Compressor impeller turbine side end surface 5 Rotating shaft 7 Housing (bearing housing)
8 Turbine housing 9 Compressor housing 10, 10 ′, 10 ″ Supercharger 11 Thrust bush 13 Positive thrust bearing 15 Anti-thrust bearing 17 Journal bearing 19 Oil passage 20 Dedicated oil passage 21 Oil drain member 21a Outer edge reduced diameter portion 21b Outer edge expansion Diameter side 21c Compressor side end face 23 of oil draining member Seal member 23a Compressor side end face 25 of seal member Seal housing 25a Inner edge enlarged diameter part 25b Inner edge reduced diameter part 26 Sleeve 26a Turbine side end face 27 of motor 27 Motor 28 Rotor 28a Turbine side of rotor End face 29 Stator

Claims (9)

A turbine impeller that is rotationally driven by exhaust gas, a compressor impeller that is rotationally driven by the rotation of the turbine impeller, compresses air, a rotary shaft that connects the turbine impeller and the compressor impeller, and a rotary shaft that rotatably supports the rotary shaft. A housing in which the bearing structure is incorporated, and an oil seal structure for preventing the lubricating oil supplied to the bearing structure from leaking to the compressor side is incorporated on the compressor side of the bearing structure. A machine,
The oil seal structure includes an oil draining member fixed to the rotating shaft, a seal housing fixed to the housing so as to surround the oil draining member on a radially outer side of the oil draining member, and an oil draining member; An annular seal member disposed between the seal housing and
The oil draining member has a portion where a substantially circular outer edge is formed in a cross section perpendicular to the axial direction at the front end of the compressor side,
Furthermore, the oil draining member has an outer edge reduced diameter portion formed at the compressor-side tip and having a radius of the outer edge smaller than other portions of the outer edge,
The seal member is fitted to the outer edge reduced diameter portion,
In the seal housing, an opening through which the oil draining member passes is formed at the center of a cross section perpendicular to the axial direction,
Furthermore, the seal housing prevents the lubricating oil from leaking to the compressor side by contacting with the seal member at a radially inner edge forming the opening.   2. The oil draining member according to claim 1, wherein the oil draining member has an outer edge enlarged diameter portion that is coupled to the outer edge reduced diameter portion from the turbine side in an axial direction and has a radius of the outer edge larger than that of the outer edge reduced diameter portion. The listed supercharger. The seal housing is
An inner edge enlarged diameter portion formed at the compressor side tip and having a radius of the inner edge larger than other portions of the inner edge;
An inner edge reduced diameter part which is coupled to the inner edge enlarged diameter part from the turbine side in the axial direction and the radius of the inner edge is smaller than the inner edge enlarged diameter part,
The outer edge in the radial direction of the seal member has a radius larger than the radius of the inner edge of the inner edge reduced diameter part, and is in contact with the inner edge of the inner edge enlarged diameter part. The listed supercharger.   The supercharger according to claim 1, wherein the oil seal structure includes a holding member that holds the seal member in a fixed position. The oil seal structure has a holding member that holds the seal member in a fixed position,
The turbine-side end surface of the holding member is in contact with the compressor-side end surface of the seal member, thereby holding the seal member between the turbine-side end surface and the outer edge enlarged diameter portion of the oil draining member. The supercharger according to claim 2, wherein   The supercharger according to claim 4 or 5, wherein the holding member is the compressor impeller.   The supercharger according to claim 4, wherein the holding member is provided between the compressor impeller and the seal member.   The supercharger according to claim 4 or 5, wherein the holding member is a sleeve provided between the compressor impeller and the seal member.   The electric motor further assisting rotation of the said rotating shaft is provided, The rotor of this electric motor is arrange | positioned as the said holding member between the said compressor impeller and the said sealing member, The Claim 4 or 5 characterized by the above-mentioned. The turbocharger described in

Images