JPH10339155A - Oil leak preventive device for supercharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely seal oil leaking from the bearing housing side to the compressor housing side in a supercharger such as a turbo-charger. SOLUTION: A flange part 20 is formed on a collar 14 installed on a shaft 4 to rotate, oil transmitted through the shaft 4 is scattered into a seal chamber 16, and a seal ring 18 facing a circular groove 19 formed in the collar 14 is installed on an inner surface of a center cylinder part 17 of a retainer 12 to prevent transmission of oil in an axial direction, where a rotary current is generated in air in the seal chamber 16 by rotation of the flange part 20 to generate tendency of oil directing toward a center part of the seal chamber 16 by inducing action by the rotary current thereby, an oil leak is caused so an overlap part 33 is formed in the center cylinder part 17 to restrict the rotary current of air only. As another application, a parting wall may be provided roughly in a radial direction in the seal chamber 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed rotating turbocharger such as a turbocharger for an internal combustion engine.
The present invention relates to a device for preventing oil for lubrication from leaking from an oil seal portion provided on a shaft of a compressor that pressurizes intake air.

[0002]

2. Description of the Related Art A general structure of a turbocharger is shown in FIG.
Shown in A shaft 4 is disposed in a bearing housing 3 connecting the compressor housing 1 and the turbine housing 2 with the shaft 4 mounted on a bearing 5, so that the shaft 4 can rotate at high speed within the bearing housing 3. An impeller 6 is attached to one end of the shaft 4 by a nut 7 so as to fit in the compressor housing 1, and a turbine rotor 8 is connected to the other end so as to fit in the turbine housing 2.

A thrust bush 9 is mounted on the shaft 4 side of the compressor housing 1 so as to rotate together with the shaft 4, and the thrust bush 9 is provided through an oil supply hole 11 of a thrust bearing 10 fixed to a bearing housing 3 by a pin (not shown). Oil is supplied inside. The thrust bearing 10 is fixed in the axial direction by a snap ring 13 via a retainer 12. To prevent the oil after lubricating the thrust bearing 10 from leaking to the impeller 6 side, a collar 14 that rotates integrally with the shaft 4 is attached to a portion covered by the retainer 12. A deflector 15 is fixed inside the retainer 12 substantially in parallel with the thrust bearing 10, thereby defining a space called a seal chamber 16 inside the retainer 12.

A central cylindrical portion 17 is formed at the center of the retainer 12 fixed to the housing so as to cover a part of the outer periphery of the collar 14 attached to the shaft 4 with a small gap. A seal ring 18 protruding further inward is attached to a part of the central cylindrical portion 17. The seal ring 18 is inserted into an annular groove 19 formed in the collar 14 so that the annular groove 19 is formed.
Are supported by a retainer 12 so as not to make contact with each other with a small gap left between the respective surfaces.

[0005] After lubricating between the thrust bush 9 and the thrust bearing 10, part of the oil passes through a gap formed between the deflector 15 fixed to the housing side and the collar 14 rotating together with the shaft 4. As shown in FIG. 9, the oil flows into the seal chamber 16 in the axial direction, but the oil does not flow directly into the gap between the seal ring 18 and the annular groove 19 of the collar 14.
A flange 20 is formed at a portion closer to the thrust bearing 10 than the annular groove 19 of FIG. And the lower part of the deflector 15 is a tongue piece 21 for oil guide,
An oil discharge port 22 is formed between the retainer 12 and the oil discharge port 22. The oil discharge port 22 joins a lubrication chamber 23 formed below the bearing 5 and the thrust bearing 10.

Therefore, a part of the oil adheres to the side surface 24 of the flange portion 20 on the side of the lubricating chamber 23 by viscous force and is given a centrifugal force by rotating together. As described above, since the oil is shaken off in the radial direction from the side surface 24 of the flange portion 20, the oil is prevented from traveling axially to the annular groove 19. The oil shaken off by the collar 20 of the collar 14 is
Drain oil which is received by the outer peripheral wall 28 of the retainer 12, flows down along the outer peripheral wall 28 by gravity, is collected at the oil discharge port 22, lubricates the bearing 5 and the thrust bearing 10, and then falls into the lubrication chamber 23. Merge and return to the oil reservoir not shown. (Refer to JP-A-55-1017130 or JP-A-6-317171 for the prior art.)

[0007]

As described above, even in the conventional turbocharger, the flange portion 20 provided on the collar 14 has the side surface on the lubrication chamber 23 side when the oil is transmitted in the axial direction. The oil is adhered to the film 24 by viscous force to cause the oil to rotate and generate a centrifugal force to shake off the oil, thereby further preventing the oil from being transmitted to the annular groove 19 in the axial direction. However, as shown in FIG. 10, the outer peripheral surface 25 of the flange portion 20 and the side surface 26 on the impeller 6 side face air in the seal chamber 16 in contact therewith, similar to the side surface 24 acting on oil. The air adheres to the outer peripheral surface 25 of the flange portion 20 and the side surface 26 on the impeller 6 side due to the viscosity and rotates together. However, since air has a smaller mass per unit volume than oil, there is not much kinetic component to be swept away in the radial direction, and as shown by arrow 27 in FIG. Of the swirling flow in the same rotation direction as the rotation direction of the shaft 4 (arrow 29).

As shown in FIG. 10, the swirling flow 27 of the air generated in the seal chamber 16 by the rotation of the flange 20 causes the oil shaken off by the flange 20 of the collar 14 to flow to the outer peripheral wall 28 of the retainer 12. After being attached, it acts to somewhat prevent the oil from flowing down toward the oil discharge port 22 by gravity. That is, the oil adhering to the outer peripheral wall 28 is attracted by the swirling flow 27 of the air, and
2 and flows along the inner surface of the outer peripheral wall 28.
In order to flow in the same rotational direction as 7, the action of gravity is applied to the oil, so that an oil stagnation portion having a shape indicated by reference numeral 30 in FIG. Occurs.

When the swirling flow 27 of air is generated in the seal chamber 16, the pressure in the central portion near the collar 14 is lower than the pressure in the outer peripheral portion in the seal chamber 16, and thus the air adheres to the outer peripheral wall 28. The oil does not flow out to the oil discharge port 22, but tends to flow along the wall surface of the retainer 12 in the direction of the collar 14 in the central portion and also in the direction of the annular groove 19. Therefore, when the thick oil stagnation portion 30 as shown in FIG.
Among them, the flow of oil from the position closest to the center of the seal chamber 16 toward the center as indicated by the dashed arrow 32 also occurs.

The swirling flow 27 of air in the seal chamber 16
Becomes stronger as the rotation speed of the shaft 4 increases,
When the shaft 4 rotates at a high speed, that is, when the internal combustion engine (not shown) is supercharged by the turbocharger, the shaft 4 flows toward the center of the seal chamber 16 for the above-described reason, and The amount of oil staying near the groove 19 increases. The oil accumulated in the vicinity of the annular groove 19 in this manner is removed when the pressure on the back surface of the impeller 6 becomes lower than the pressure in the central portion of the seal chamber 16 during operation. The oil leaks into the compressor housing 1 through the gap and is sucked into the internal combustion engine, and partly burns in the combustion chamber. However, most of the oil is generally nonflammable, so most of the oil does not burn and is discharged together with the exhaust gas into the atmosphere. As a result, the oil not only causes air pollution but also causes a lack of oil in the turbocharger.

The present invention addresses the above-mentioned problems in the prior art, and in a turbocharger such as a turbocharger, a collar flange provided on a shaft at a boundary portion between a bearing housing and a compressor housing is provided. Without interfering with the so-called "scattering action" that shakes off the oil, it is possible to prevent oil from entering the vicinity of the seal ring cooperating with the annular groove provided in the collar,
This provides an improved oil leakage prevention device for a turbocharger that can reliably prevent the lubricating oil in the bearing housing from leaking from the boundary portion with the compressor housing to the compressor side. It is intended to be.

[0012]

According to the present invention, as a means for solving the above-mentioned problems, there is provided a device for preventing oil leakage of a supercharger as set forth in the claims.

[0013] In the oil leakage prevention device according to the first aspect, in order to suppress the swirling flow of the air particularly inside the seal chamber, the retainer is provided at the axial end of the center tube portion with the collar flange portion. Since the overlap portion is provided close to and substantially covers the overlap portion, the overlap portion covers the flange portion at the close position, and the outer peripheral surface of the flange portion and the side surface on the compressor housing side come into contact with air in the seal chamber. Limit what you do. Accordingly, it is possible to prevent the collar portion from rotating the air to generate a swirling flow. Since the swirling flow of air is suppressed in this manner, when the oil transmitted along the shaft from the bearing housing side is shaken off by the end face of the flange portion on the lubrication chamber side, it is swirled by the center of the seal chamber. The oil does not flow toward the portion, and oil is prevented from leaking to the compressor housing side beyond the seal ring.

[0014] In this case, a tapered inner peripheral surface may be provided at a position where the overlap portion faces the outer peripheral surface of the flange portion so as to reduce or expand its diameter toward the distal end surface in the axial direction. Since it becomes possible to make the gap between the overlap portion and the flange portion closer together without contacting them,
The effect of suppressing the generation of the swirling flow by the overlap portion is further enhanced, and the effect of preventing oil leakage is further enhanced. The axial end surface of the overlap portion is preferably aligned so as not to exceed the side surface of the flange portion on the lubrication chamber side, preferably on the same surface, thereby maintaining a high swirl flow suppressing effect of the overlap portion. However, the oil can be sufficiently scattered by the flange.

The oil leakage prevention device according to the fifth aspect is characterized in that one or more partition walls are attached to the seal chamber from the center toward the outer periphery. The partition directly suppresses the swirling flow of air in the sealing chamber, but also acts to guide the oil shaken off by the flange so as not to return toward the center of the sealing chamber. More specifically, the partition wall may be inclined with respect to the radial direction of the seal chamber so as to deflect the swirling flow of the air impinging on the partition wall and the scattered oil toward the outer peripheral direction of the seal chamber. It is desirable to form a passage between the outer peripheral side and the inner surface of the outer peripheral wall of the retainer in order to allow the oil colliding therewith to pass therethrough.
Since the swirling flow of air is suppressed in this way, oil is prevented from flowing toward the center portion of the seal chamber by the swirling flow, and oil is prevented from leaking to the compressor housing side beyond the seal ring. You.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A main part of a first embodiment of a device for preventing oil leakage of a supercharger according to the present invention will be described with reference to FIG. This oil leakage prevention device is provided at the boundary between the compressor housing 1 and the bearing housing 3 in the turbocharger as shown in FIG. A seal chamber 1 formed by a device, that is, a collar 20 formed on a collar 14 attached to the shaft 4, and a retainer 12 and a deflector 15 for receiving oil shaken off by the collar 20.
6, an annular groove 19 also formed in the collar 14,
Since it is used in place of the oil leakage prevention device including the seal ring 18 provided on the retainer 12 side so as to cooperate with the oil leakage prevention device, the components substantially the same as those in the prior art are described in the present invention. In the embodiments, the same reference numerals are given, and duplicate detailed description will be omitted.

As a feature of the first embodiment shown in FIG. 1, the tip of the central cylindrical portion 17 of the retainer 12 extends longer in the axial direction than the conventional example shown in FIG. That is, the thin overlap portion 33 is formed integrally so as to cover the entire portion. Needless to say, the overlap portion 33 may be manufactured separately from the center tube portion 17 and attached to the tip of the center tube portion 17 by welding or the like. The tip surface 34 of the overlap portion 33 does not exceed the side surface 24 of the flange portion 20 on the lubrication chamber 23 side,
However, the length of the overlapping portion 33 projecting in the axial direction is determined so that the overlapping portion 33 can substantially completely cover the side surface 26 of the flange portion 20 on the impeller 6 side and the outer peripheral surface 25, The overlapping portion 33 does not hinder the scattering of the oil on the side surface 24 due to the rotation of the flange portion 20.

In the first embodiment, as described above, as the extension of the central cylindrical portion 17 of the retainer 12, the overlapping portion 3
3, the scattering action of the oil by the rotation of the flange portion 20 is performed in the same manner as in the conventional case, and the oil transmitted from the bearing housing 3 side to the compressor housing 1 side in the axial direction along the shaft 4 is shaken off. Retainer 1
The oil is collected by the outer peripheral wall 28 and caused to flow down by gravity so that the oil discharge port 22 can be operated without any trouble.
Can be discharged from At the same time, the collar 20
The outer peripheral surface 25 and the side surface 26 on the impeller 6 side are
The swirling flow of the air in the airbag 6 is intended to be swirled, since these portions are covered by the overlap portion 33 and only a very small space is formed therein. Such a thing does not occur. Therefore, the oil does not collect at the center of the seal chamber 16 due to the attraction effect of the swirling flow of air, and does not leak from the seal ring 18 to the compressor housing 1 side.

FIG. 2 shows a main part of an oil leakage prevention device according to a second embodiment as a modification of the first embodiment described with reference to FIG. The smaller the gap between the outer peripheral surface 25 of the flange portion 20 and the inner peripheral surface 35 of the overlap portion 33 is, the smaller the effect on the oil flow in the seal chamber 16 is even if a swirling air flow is generated there. Therefore, in the second embodiment shown in FIG. 2, the inner peripheral surface 35 of the overlap portion 33 is formed as a tapered surface whose diameter decreases toward the distal end, so that the distal end of the overlap portion 33 and the flange portion 20 are formed.
Is characterized in that the opening area of the gap between the outer peripheral surface 25 of the flange portion 20 and the inner peripheral surface 35 of the overlap portion 33 with respect to the seal chamber 16 is reduced to such an extent that no contact occurs. Thus, the oil leakage prevention device of the second embodiment has a higher oil leakage prevention effect than that of the first embodiment.

FIG. 3 shows an essential part of an oil leakage prevention device according to a third embodiment which is also a modification of the first embodiment. The peripheral surface 36 is formed as a tapered surface whose diameter increases toward the tip. By doing so, the overlapping portion 33 is formed by casting the retainer 1.
When manufacturing as an integral part of 2, the manufacturing is facilitated because the overlap portion 33 extends in the direction in which the mold is removed.

FIGS. 4 to 6 show the structure and operation of an oil leakage prevention device according to a fourth embodiment of the present invention. As is clear from FIG. 4 or FIG. 5, in the fourth embodiment, unlike the oil leakage prevention device of the first to third embodiments, a seal chamber 16 formed by a retainer 12 and a deflector 15 is provided. The feature is that one or more partition walls 37 in a direction slightly different from the radial direction are provided. If the rotation direction of the shaft 4 is the direction indicated by the arrow 29 in the sectional view of FIG.
When only one is provided, it is most appropriate to provide the partition wall 37 in the lower right second quadrant region defined by the Y axis and the X axis as shown in FIG. In the area of the first quadrant. However, when practicing the present invention, the partition wall 37 may be provided in the region of the lower left third quadrant or the upper left quadrant in FIG. FIG. 4 illustrates a case where the sensor is provided in the first quadrant or the fourth quadrant.

The first purpose of providing the partition wall 37 in a direction close to the radial direction is to forcibly suppress the swirling flow of air generated in the seal chamber 16 due to the rotation of the flange 20 as described above. In addition, as a second object, when the oil is shaken off by the flange portion 20 and hits the partition wall 37 together with the swirling flow of the air, the swirling flow of the oil and the air is directed toward the outer periphery as much as possible. By diverting below the seal chamber 16, the oil is directed toward the oil outlet 22 (see FIGS. 7 and 8) to prevent the oil from approaching the central portion of the seal chamber 16.

Therefore, the partition wall 37 is not positioned in the radial direction of the seal chamber 16 as shown in FIGS. 5 and 6, and the swirling flow of oil or air colliding with the seal chamber 16 is prevented from flowing.
6 is inclined at a slight angle with respect to the radial direction in order to deflect in the outer circumferential direction. The partition wall 37 is in a direction (incident direction) where the swirling flow of the air generated simultaneously with the scattering action of the oil due to the rotation of the flange portion 20 hits the partition wall 37, that is, with respect to the circle centered on the shaft 4 at the point where the streamline of the swirling flow hits. It is preferable that the arrow 38 indicating the tangential direction is on the inner peripheral side of the seal chamber 16 with respect to the normal 39 of the partition wall 37. Thereby, the swirling flow of the air and the oil hitting the partition wall 37 along the flow are not directed toward the center direction 42 but are diverted toward the outer peripheral direction 43, so that the seal ring 1 at the center portion is formed.
It is possible to prevent the oil from rotating to 8 or the like.

In this case, as is apparent from the drawing, at least the outer peripheral wall 28 of the retainer 12 is
It is preferable to provide a passage 40 through which oil passes. After the oil shaken off by the flange portion 20 adheres to the outer peripheral wall 28, the passage 40 forms the outer peripheral wall 28 by gravity.
This is to allow the oil to flow down toward the oil outlet 22. Thus, the stagnation of oil on the inner surface of the outer peripheral wall 28 due to the provision of the partition wall 37 can be prevented.

As described above, in the oil leakage prevention device according to the fourth embodiment of the present invention, the provision of the partition wall 37 suppresses the swirling flow of air, and allows oil to flow into the vicinity of the seal ring 18 at the center. And oil leakage to the outside can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing a structure of a main part of a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional front view showing a structure of a main part of a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional front view showing a structure of a main part of a third embodiment of the present invention.

FIG. 4 is a longitudinal sectional front view showing a structure of a main part according to a fourth embodiment of the present invention.

FIG. 5 is a cross-sectional side view showing a structure of a main part of a fourth embodiment.

FIG. 6 is a cross-sectional side view of a main part showing the operation of the fourth embodiment.

FIG. 7 is a vertical sectional front view showing the entire structure of a general turbocharger.

8 is a longitudinal sectional front view showing a part of FIG. 7 in an enlarged manner.

FIG. 9 is a vertical sectional front view showing a structure of a main part of a conventional example.

FIG. 10 shows the operation of the main part of the conventional example.
It is a transverse side view in the X-ray.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Compressor housing 3 ... Bearing housing 4 ... Shaft 5 ... Bearing 6 ... Impeller 10 ... Thrust bearing 11 ... Oil supply hole 12 ... Retainer 14 ... Collar 15 ... Deflector 16 ... Seal chamber 17 ... Central cylindrical part formed in the retainer 12 18 ... a seal ring provided on the central cylindrical portion 17 ... an annular groove provided on the collar 14 ... a flange portion provided on the collar 14 ... an oil outlet 23 ... a lubrication chamber 24 ... a lubrication chamber 23 of the flange portion 20 Side surface 25 ... Outer peripheral surface of flange 20 26 ... Side surface of flange 20 on impeller 6 side 27 ... Arrow indicating swirling flow of air 28 ... Outer peripheral wall of retainer 12 30 ... Oil retaining portion 33 ... Overlap portion 34 ... Tip surfaces 35 and 36 of the overlap portion 33... Inner peripheral surface of the overlap portion 33. 37. Partition walls 38. (Tangential direction of the circle) 39 ... the normal 40 ... passage direction

Claims (7)

[Claims] The present invention relates to a method for preventing the oil for lubricating a bearing portion for supporting a shaft of a turbocharger from leaking from a bearing housing side to a compressor housing side along the shaft. A collar attached to the shaft at the boundary portion and integrally rotating, a retainer attached to the bearing housing side to form a seal chamber covering at least a part of the collar, and also attached to the bearing housing side. A deflector, and a flange formed on the collar in the seal chamber to radially shake off oil that has transmitted axially from the bearing housing side to the compressor housing side, and a collar formed on the collar. Annular groove And a seal ring provided so as to protrude inward from the central cylindrical portion of the retainer corresponding to the annular groove formed in the collar, and further suppresses a swirling flow of air inside the seal chamber. To do
An oil leakage prevention device for a turbocharger, comprising: an end portion in the axial direction of the central cylindrical portion of the retainer, the overlap portion being close to and substantially covering the collar portion of the collar. . 2. The overlap portion according to claim 1, wherein an inner peripheral surface of which the diameter is reduced toward an axial front end surface is provided at a position facing an outer peripheral surface of the flange portion. The device for preventing oil leakage of a supercharger described in (1). 3. The overlap portion has an inner peripheral surface whose diameter increases toward an axial front end surface at a position facing the outer peripheral surface of the flange portion. The device for preventing oil leakage of a supercharger described in (1). 4. The method according to claim 1, wherein an axial end surface of the overlap portion has an axial length not exceeding a side surface of the flange portion on the side of the lubrication chamber. An oil leakage prevention device for a turbocharger described in (1). 5. In order to prevent oil lubricating a bearing portion supporting a shaft of a supercharger from leaking from the bearing housing side to the compressor housing side along the shaft, the bearing housing and the compressor housing are connected to each other. A collar attached to the shaft at the boundary portion and integrally rotating, a retainer attached to the bearing housing side to form a seal chamber covering at least a part of the collar, and also attached to the bearing housing side. A deflector, and a flange formed on the collar in the seal chamber to radially shake off oil that has transmitted axially from the bearing housing side to the compressor housing side, and a collar formed on the collar. Annular groove And a seal ring provided so as to protrude inward from the central cylindrical portion of the retainer corresponding to the annular groove formed in the collar, and further suppresses a swirling flow of air inside the seal chamber. To do
An oil leakage prevention device for a turbocharger, comprising one or more partition walls attached from a central portion to an outer peripheral direction in the seal chamber. 6. The partition wall is inclined with respect to the radial direction of the seal chamber so as to deflect the swirling flow of air impinging on the partition wall and the shaken oil toward the outer periphery of the seal chamber. The oil leakage prevention device for a turbocharger according to claim 5, wherein 7. The partition wall has a passage formed at least on the outer peripheral side with the inner surface of the outer peripheral wall of the retainer in order to allow oil flowing along the outer peripheral wall of the retainer to pass therethrough. An oil leakage prevention device for a turbocharger according to claim 5.