JPH064034Y2 - Tarbooger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a turbocharger used in an internal combustion engine of an automobile or the like.

(Prior Art) In recent years, turbochargers have been used to improve acceleration performance in internal combustion engines such as automobiles. In this turbocharger, the exhaust gas discharged from the internal combustion engine rotates the turbine rotor, and the compressor rotor integrated with the turbine rotor rotates, thereby supplying compressed air to the internal combustion engine.

As a turbocharger, the actual exploitation number is 59-024557.
The above-mentioned publication is provided.

In the turbocharger according to Japanese Utility Model Laid-Open No. 59-024557, lubricating oil is supplied to a shaft connecting the turbine rotor and the compressor rotor in order to smooth the rotation of the turbine rotor and the compressor rotor in a high speed region. .

As shown in FIG. 4, this turbocharger serves as a housing 103 having a bearing chamber 102 having an oil supply passage 100 at an upper part and an oil discharge port 101 at a lower part, and a bearing for receiving oil supply from the oil supply passage 100. Radial bearing 104, thrust bearing 111
And radial bearing 104, thrust bearing 1
A shaft 105 rotatably held by 11, a compressor rotor 106 and a turbine rotor 107 integrally provided at an end of the shaft 105, and a bush fixed to the shaft 105 between the compressor rotor 106 and a thrust bearing 111. 108, a seal plate 109 having an inner peripheral surface facing the outer peripheral surface of the bush 108 and located on the compressor rotor 106 side, and a slinger 110 held by the housing 103.

The slinger 110 has a circular end surface 110 a facing the outer peripheral surface 108 a of the bush 108 and guides the oil to the oil discharge port 101.

In this turbocharger, when the turbine rotor 107 is rotated by the exhaust gas of the internal combustion engine, the shaft 105 rotates in the radial bearing 104, which causes the compressor rotor 106 to rotate via the shaft 105 and the rotation of the compressor rotor 106. , Compressed air is supplied to the internal combustion engine.

When the compressor rotor 106 rotates in this way, oil is supplied from the oil supply passage 100 to the radial bearing 104 and the thrust bearing 111, and the rotation of the shaft 105 is smoothed.

By the way, in the above-mentioned turbocharger, the oil that has passed through the radial bearing 104 and the thrust bearing 111 is discharged from the oil discharge port 101 along the slinger 110 in the arrow B direction.

When the output of the internal combustion engine increases and the amount of exhaust gas increases, the rotation speed of the turbine rotor 107 increases and the shaft 105
Increases the rotation speed of. At this time, the amount of oil supplied to the internal combustion engine increases, and therefore the amount of oil supplied to the oil supply passage 100 also increases. Therefore, the amount of oil supplied to the radial bearing 104 and the thrust bearing 111 increases.

Then, the oil passes through the gap between the circular end surface 110 a of the slinger 110 and the outer peripheral surface 108 a of the bush 108, and the oil passes through the seal plate 109 and the slinger 11.
It penetrates into the tightening 112 between 0. However, since the oil that has entered the chamber 112 is blocked by the seal plate 109,
It does not enter the compressor rotor 106 side,
Therefore, the oil that has entered the chamber 112 moves in the direction of arrow E and is discharged from the oil discharge port 101.

(Problems to be Solved by the Invention) By the way, when the output of the internal combustion engine increases and the exhaust gas amount further increases, and the rotation speed of the shaft 105 further increases, the amount of oil supplied to the radial bearing 104 and the thrust bearing 111 is increased. Is further increased. As a result, arrow B
The supplied oil cannot be completely discharged only by discharging in the direction of arrow E. Therefore, there arises a problem that oil enters the compressor rotor 106 side through the gap between the inner peripheral surface of the seal plate 109 and the outer peripheral surface 108a of the bush 108.

When the oil enters the compressor rotor 106 side in this way, the oil is sucked into the intake hole of the internal combustion engine and affects the output of the internal combustion engine.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a turbocharger that solves the problem that oil supplied to a bearing that rotatably holds a shaft enters the compressor rotor side. .

[Structure of the Invention] (Means for Solving the Problems) A turbocharger according to the present invention includes a housing having a bearing chamber having an oil supply passage in the upper part and an oil discharge port in the lower part, and oil supply from the oil supply passage. Bearing held in the housing, a shaft rotatably held by the bearing, a compressor rotor and a turbine rotor integrally provided at an end of the shaft, and a shaft between the compressor rotor and the bearing. The fitted bush and the seal plate, which is held by the housing and has the bush insertion hole defined by the inner peripheral surface that faces the outer peripheral surface of the bush and is inserted through the bush, is located on the compressor rotor side and the housing. A circular shape that is held and the bush is inserted and faces the outer peripheral surface of the bush between the seal plate and the bearing. In a turbocharger having a surface and a slinger that guides oil to an oil discharge port, the bush is arranged between the slinger and the seal plate, and a first flange portion having a side surface closely facing the bearing side surface of the slinger. And a second flange portion having a smaller outer diameter than the outer diameter of the first flange portion, which faces the bearing side surface of the peripheral edge of the bush insertion hole in the seal plate in the axial direction of the shaft. It is characterized by having.

The bush refers to a cylindrical member fitted in the hole. The bush characterizing the present invention has a first collar portion and a second collar portion. The first collar portion is a portion having a large outer peripheral diameter, which has a side surface that closely faces the bearing side surface of the slinger. The second collar portion is a portion having an outer diameter smaller than that of the first collar portion adjacent to the side surface of the slinger on the compressor side. The first brim portion and the second brim portion are continuously formed along the circumference of the bush.
The outer peripheral diameter of the second flange portion is preferably smaller than the diameter of the circular end surface of the slinger facing the outer peripheral surface of the bush.

The housing, bearings, compressor rotor, turbine rotor, seal plate, slinger, etc. may have the same configurations as conventional ones.

(Operation) In the turbocharger according to the present invention, the turbine rotor is rotated by the exhaust gas of the internal combustion engine, so that the shaft is rotated within the bearing and the compressor rotor is rotated through the shaft, whereby compressed air is generated. Is supplied to the intake hole.

At this time, the oil sent to the oil supply passage is supplied to the bearing. Therefore, the shaft that rotates in the bearing smoothly rotates because of the oil, and the compressor rotor and turbine rotor of the turbocharger operate smoothly.

By the way, in the turbocharger, the oil supplied to the bearing is discharged from the oil discharge port along the slinger as in the conventional case.

On the other hand, when the output of the internal combustion engine further increases and the exhaust gas amount further increases, the oil supply amount to the oil supply passage increases,
Therefore, the oil supply amount to the bearing is further increased.

At this time, in the turbocharger according to the present invention, since the bush rotates together with the shaft, the first flange portion and the second flange portion also rotate at a considerably high speed. Therefore, a large centrifugal force acts on the oil near the first and second collars. As a result, the oil is suppressed from passing over the slinger, and the invasion of the oil into the chamber between the slinger and the seal plate is suppressed.

The reason is that even if the oil enters between the first collar portion and the slinger, the oil is returned to the radially outward direction by the centrifugal force generated by the rotation of the first collar portion, and further, Even if oil enters between the second flange and the slinger, the centrifugal force generated in the first flange is larger than the centrifugal force generated in the second flange, so that the oil that has entered the first flange is Due to the centrifugal force generated by the rotation of the collar portion, it is returned to the side of the first collar portion, and since the centrifugal force generated in the first collar portion is larger than the centrifugal force generated in the second collar portion, the slinger acts as a bush. This is because the air between them is pulled toward the first brim portion side, so that oil is unlikely to enter in the direction opposite to the direction in which the air is pulled.

(Embodiment) An embodiment of the turbocharger according to the present invention will be described with reference to FIGS.

The turbocharger according to this embodiment is applied to an internal combustion engine of an automobile.

(Structure of Embodiment) As shown in FIG. 1, a turbocharger according to this embodiment includes a housing 1, a radial bearing 2 as a bearing, a thrust bearing 3, a shaft 4, a compressor rotor 5, and a turbine rotor 6. , Bush 7
And a seal plate 8 and a slinger 9.

The housing 1 is bonded to an internal combustion engine, and has a bearing housing 15 having a bearing chamber 12 having an oil supply passage 10 at an upper part and an oil discharge port 11 at a lower part, and a turbine housing having a turbine chamber 16a connected to the bearing housing 15. 16 and a compressor housing 17 connected to the bearing housing 15 and having a compressor chamber 17a.

The oil supply passage 10 is communicated with the discharge port of an oil pump or the like so that oil is supplied. The turbine chamber 16a of the turbine housing 16 is connected to an exhaust hole that discharges exhaust gas of the internal combustion engine. The compressor chamber 17a of the compressor housing 17 is connected to an intake passage that intakes air to the internal combustion engine.

The radial bearing 2 is held in the bearing chamber 12 of the housing 1 and is subjected to a radial load acting on the shaft 4. The radial bearing 2 has an oil hole 2a. Similarly, the thrust bearing 3 is held in the bearing chamber 12 of the housing 1 and is subjected to an axial load acting on the shaft 4. The thrust bearing 3 has an oil hole 3a. Oil hole 2a of radial bearing 2 and oil hole 3a of thrust bearing 3
Is connected to the oil supply passage 10 and is connected to the oil supply passage 1
Oil supply from 0.

The shaft 4 has a step portion 4 a, and is rotatably held in the radial bearing 2 and the thrust bearing 3 by the radial bearing 2 and the thrust bearing 3. A turbine rotor 6 is integrally formed at one end of the shaft 4.

The bush 7 has a cylindrical shape and is fixed to the shaft 4 between the compressor rotor 5 and the thrust bearing 3. In this embodiment, the bush 7 and the radial bearing 2
A second bush 70 having a cylindrical shape is inserted between and.

The radial bearing 2, the thrust bearing 3, the second bush 70, the bush 7, and the compressor rotor 5 are inserted into the shaft 4 described above, and these are fastened with a nut 42. Therefore, when the shaft 4 rotates, the second bush 70, the bush 7, and the compressor rotor 5, which are tightened with the nut 42, rotate integrally with the shaft 4 in the circumferential direction at almost the same rotation speed as the shaft 4.

As shown in FIG. 2, the seal plate 8 is fixed to the bearing housing 15 of the housing 1 by a snap ring 8c and separates the bearing chamber 12 of the bearing housing 15 and the compressor chamber 17a of the compressor housing 17 from each other. , Located on the compressor rotor 5 side. As shown in FIG. 2 and FIG. 3, the seal plate 8 has the bush 7 inserted therethrough and the outer peripheral surface 7 of the bush 7.
It has an inner peripheral surface 80 facing a. A bush insertion hole 80h is formed on the inner peripheral surface 80. The seal plate 8
Between the bearing housing 15 and the seal member 8
a is interposed, and a seal ring 8b is interposed between the inner peripheral surface 80 of the seal plate 8 and the outer peripheral surface 7a of the bush 7.

The slinger 9 guides oil to the oil discharge port 11 and is fixed to the bearing housing 15 side of the housing 1. As shown in FIG. 2, the slinger 9 has the bush 7 inserted therein, and has a circular end surface 91 facing the outer peripheral surface 7 a of the bush 7 between the seal plate 8 and the thrust bearing 3.

Now, in the turbocharger according to the present embodiment, the bush 7 has an outer peripheral surface 7a, as shown in FIG.
It is characterized by having a first brim portion 73 and a second brim portion 75.

As shown in FIG. 2, the first collar portion 73 is continuous in the circumferential direction of the bush 7 and has a side surface 73a. The side surface 73a of the first collar portion 73 closely faces the side surface 92 of the slinger 9 on the thrust bearing 3 side with a minute gap therebetween.
The outer diameter of the first collar portion 73 is larger than the inner diameter of the circular end surface 91 of the slinger 9. Therefore, the slinger 9 and the first brim portion 73 have a structure in which they overlap each other through a minute gap.

The second brim portion 75 is continuous in the circumferential direction of the bush 7. The outer diameter of the second collar portion 75 is smaller than the outer diameter of the first collar portion 73, that is, smaller than the inner diameter of the circular end surface 91 of the slinger 9. Therefore, the slinger 9 and the second brim portion 7
No. 5 has a structure that does not overlap. Second
The flange portion 75 is in close contact with the bearing-side side surface 8i of the inner projection 8e of the seal plate 8, that is, the bearing-side side surface of the peripheral edge of the bush insertion hole 80h in a direction parallel to the axial direction of the shaft 4 in a butted state. Facing each other.

(Operation and Effect of Embodiment) In the turbocharger according to this embodiment, the turbine rotor 6 is rotated by the exhaust gas of the internal combustion engine, the compressor rotor 5 is rotated via the shaft 4, and the compressed air is an intake hole of the internal combustion engine. Is supplied to. At this time, the oil supply passage 10
The oil sent from is received by the radial bearing 2 and the thrust bearing 3. Therefore, the shaft 4 that rotates within the radial bearing 2 and the thrust bearing 3 rotates smoothly, and the turbocharger operates smoothly.

By the way, in the turbocharger, the oil that has passed through the radial bearing 2 and the thrust bearing 3 is slinger 9
The oil is then discharged from the oil discharge port 11 to an oil pan or the like.

Further, when the output of the internal combustion engine further increases and the amount of exhaust gas further increases, the rotation speed of the turbine rotor 6 rotated by the exhaust gas increases, and thus the rotation speed of the shaft 4 further increases. In this case, the amount of oil supplied to the radial bearing 2 and the thrust bearing 3 is further increased.

At this time, in the turbocharger according to the present embodiment, since the bush 7 rotates together with the shaft 4, the first flange portion 73 and the second flange portion 75 also rotate. Therefore, the first
The oil near the brim portion 73 and the second brim portion 75 rotates together with the bush 7. Therefore, centrifugal force acts on the oil near the first brim portion 73 and the second brim portion 75, and as a result, the oil swirls. To do. Therefore, even when the amount of oil supplied into the oil supply passage 10 is increased, the entry of oil into the compressor rotor 5 side is suppressed unlike the conventional case.

The reason is that even if the oil enters between the first collar portion 73 and the oil slinger 9, the oil is returned to the radially outward direction by the centrifugal force generated by the rotation of the first collar portion 73. Further, even if oil enters between the second flange portion 75 and the slinger 9, the centrifugal force generated at the first flange portion 73 is larger than the centrifugal force generated at the second flange portion 75, The oil that has entered the first brim 73
The centrifugal force generated by the rotation of the first flange 73 is returned to the side of the first flange 73, and the centrifugal force generated in the first flange 73 is larger than the centrifugal force generated in the second flange 75. This is because the air between the bush 7 and the bush 7 is pulled toward the first brim portion 73, so that oil is unlikely to enter in the direction opposite to the direction in which the air is pulled.

In particular, in this embodiment, the second flange 75 is butted against the inner protrusion 8e of the seal plate 8 in a direction parallel to the axial direction of the shaft 4 with a minute gap therebetween so as to face and closely face the second flange 75. Since the centrifugal force acts on the oil, it is advantageous to pull back the oil, which is about to enter the seal ring 8b, to the chamber 85 side by the centrifugal force generated in the second flange portion 75.

By the way, the centrifugal force acting on the oil in the vicinity of the first flange portion 73 and the second flange portion 75 increases as the rotation speed of the bush 7 and the rotation speed of the shaft 4 increase. That is, the centrifugal force that acts on the oil near the first flange portion 73 and the second flange portion 75 is proportional to the square of the rotation speed of the bush 7. Therefore, the centrifugal force acting on the oil increases as the rotational speed of the turbine rotor 6 increases and the rotational speed of the shaft 4 and bush 7 increases.

Therefore, the higher the output of the internal combustion engine and the faster the shaft 4 of the turbocharger rotates, the higher the sealing performance can be secured.

Moreover, in this embodiment, since the bush 7 and the slinger 9 are not in contact with each other, no mechanical loss occurs between the bush 7 and the slinger 9, and the performance of the turbocharger is not deteriorated.

Furthermore, since the bush 7 and the slinger 9 are not in contact with each other, the sealability does not deteriorate even when used for a long period of time.

[Advantages of the Invention] According to the turbocharger of the present invention, the sealing performance can be secured, and in particular, the higher the rotation speed of the shaft, the higher sealing performance can be secured.
Therefore, it is possible to prevent oil from entering the compressor rotor side.

Particularly, according to the turbocharger according to the present invention, on the bearing-side side surface of the periphery of the bush insertion hole of the seal plate,
In the direction parallel to the axial direction of the shaft, the second flange portions closely face each other in a butted state, and the second flange portion functions as an obstacle against oil intrusion, so that the oil is inserted into the bush insertion hole. Can be suppressed. Furthermore, since it is advantageous to pull back the oil that tries to enter the compressor rotor side by the centrifugal force generated in the second flange portion,
Further sealability can be secured.

[Brief description of drawings]

FIG. 1 is a sectional view of a turbocharger, FIG. 2 is a sectional view of essential parts, and FIG. 3 is a sectional view showing a seal structure between a seal plate and a bush. FIG. 4 is a sectional view of a conventional turbocharger. In the figure, 1 is a housing, 10 is an oil supply passage, 11 is an oil discharge port, 2 is a radial thrust (bearing), 3 is a thrust bearing (bearing), 4 is a shaft, 5 is a compressor rotor, 6 is a turbine rotor, 7 Is bush, 7
Reference numeral 3 is a first flange portion, 75 is a second flange portion, 8 is a seal plate, and 9 is a slinger.

Claims (1)

[Scope of utility model registration request] 1. A housing having a bearing chamber having an oil supply passage on the upper side and an oil discharge port on the lower side, a bearing which is supplied with oil from the oil supply passage and held in the housing, and rotatable by the bearing. A shaft that is held, a compressor rotor and a turbine rotor that are integrally provided at the end of the shaft, a bush that is fitted to the shaft between the compressor rotor and the bearing, and that is held by the housing. A seal plate located on the compressor rotor side and having a bush insertion hole defined by an inner peripheral surface that faces the outer peripheral surface of the bush and through which the bush is inserted. And has a circular end surface facing the outer peripheral surface of the bush between the seal plate and the bearing, and guides the oil to the oil discharge port. In turbochargers with a ringer, the bush has a first flange portion having a side surface closely facing the said bearing side surface of the slinger, is disposed between the slinger and the seal plate,
A second flange portion, which faces the bearing side surface of the periphery of the bush insertion hole of the seal plate in the axial direction of the shaft, in close contact with each other, and has an outer diameter smaller than the outer diameter of the first collar portion; A turbocharger characterized by being equipped with.