JPH0752339Y2 - Supercharger - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial field of application) The present invention is a turbocharger having a bearing mechanism of a forced lubrication system,
The present invention relates to a turbocharger that can be used in mechanical centrifugal turbochargers, gas turbines, and the like.

(Prior Art) FIG. 13 shows a conventional turbocharger proposed in Japanese Utility Model Publication No. 60-137128, which has an exhaust inlet 5 and an exhaust outlet 6 of an exhaust passage for engine combustion gas. A compressor housing 10 having a turbine housing 7 and an air inlet 8 and a pressurized air outlet 9 for an engine intake passage, and a turbine rotor 11 located in the middle of the two housings 7 and 10 and at one end in the exhaust passage of the turbine housing 7. And compressor housing 10 at the other end
The bearing housing 14 supports the rotor shaft 13 to which the compressor rotor 12 located in the intake passage is attached.

A radial bearing 15 is arranged between an outer peripheral surface of a substantially central portion of the rotor shaft 13 and a bearing housing 14 facing the rotor shaft 13, and the radial bearing 15 supports the rotor shaft 13 in the bearing housing 14. It is arranged to be rotatable. Oil is supplied to the radial bearing 15 from an oil passage 16 provided in the bearing housing 14.

In addition, the rotor shaft 13
There are first and second thrust bushes 17 and 18 that rotate together, and a thrust bearing 19 is arranged between the bushes 17 and 18. The thrust bearing 19 is fixed by a pin 20 so as not to rotate, and is fixed in the bearing housing 14 by a snap ring 22 via a seal plate 21 so as not to move in the axial direction. Further, oil passages 23, 24, 25 communicating with the oil passages are provided so that oil is supplied to the thrust bearing 19 when the rotor shaft 13 rotates. Further, in the case of a turbocharger, the rotor shaft 13 rotates at a very high speed (100,000 to 200,000 rpm), so that the bearing is generally forcibly lubricated with engine oil.

(Problems to be Solved by the Invention) However, in the conventional turbocharger shown in FIG. 13, when the rotation of the rotor shaft becomes large, the amount of flowing oil increases and fills the vacant chamber 26. In a turbocharger having a bearing mechanism of forced oil circulation, the oil sealability between the bearing chamber and the compressor chamber is important. However, in the conventional turbocharger shown in FIG. 13, since the amount of oil that flows into the empty chamber 26 is larger than the amount that is discharged at high speed rotation, the oil flows out toward the empty chamber 27, and eventually the compressor side. There was a drawback that oil leaked out.

The present invention aims to provide a supercharger that can solve the above-mentioned conventional problems by improving the structure for discharging oil after lubricating the thrust bearing.

[Constitution of device]

(Means for Solving the Problem) For this reason, the present invention provides a thrust bearing 34 that receives the thrust force of the rotor shaft 30 to which the compressor rotor is fixed, and
A thrust bush having a flange portion fixed to the rotor shaft 30, a compressor rotor and a thrust bearing 34.
A sealing plate that is provided between the thrust bearing 34 and the thrust bearing 34 and blocks the lubricating oil supplied to the thrust bearing 34.
A space A formed between the space 36 and the flange of the thrust bush is provided, and a communication hole 40 communicating with the space is provided above the thrust bearing 34, and the communication hole and the oil drain chamber D are provided.
A passage 41 for communicating with and is provided, and the communication hole 40 is provided on the outer peripheral side of the flange portion of the thrust bush, and these are means for solving the problem.

(Operation) The oil supplied from the oil passage is discharged to the oil drain chamber after lubricating the bearing surfaces on both sides of the thrust bearing, but when the turbocharger rotates at high speed, the amount of oil supplied to the thrust bearing increases. Oil accumulates in the space between the thrust bearing and the sealing plate. This oil is discharged into the oil drain chamber through a passage that connects the empty chamber formed in the thrust bearing and the oil drain chamber. Further, when the turbocharger rotates at a low speed, air flows from the oil drain chamber through the passage into the empty chamber to accelerate the discharge of oil from the empty chamber.

(Embodiment) The present invention will be described below with reference to the embodiments of the drawings. FIGS. 1 to 12 show an embodiment of the present invention. FIG. 1 is an enlarged side sectional view of a thrust bearing portion in a supercharger of the present invention. In the figure, reference numeral 30 denotes a rotor shaft to which a compressor rotor 31 is fixed, and the rotor shaft 30 is a thrust bush 32,3.
It is supported by the bearing housing 35 via the thrust bearing 34 and the thrust bearing 34. In the figure, 36 is a sealing plate for separating the vacant chamber A and the vacant chamber B, and 37 is the vacant chamber B and the vacant chamber C.
Sealing rings 38 and 39 for separating the above are oil passages provided in the bearing housing 35 and the thrust bearing 34.

Next, the operation will be described. The oil supplied from the oil passage 38 to the oil passage 39 in the thrust bearing 34 lubricates the bearing surfaces on both sides of the thrust bearing 34, and then the passage a
Through the oil drain chamber D. However, a part of it penetrates into the empty space B from the empty space A through the gap between the sealing plate 36 and the thrust bush 32. However, since the gap between the sealing plate 36 and the thrust bush 32 is very small, the amount of oil that enters the vacant chamber B is extremely small. Therefore, this oil is discharged from the passage b and further provided with the ceiling 37, so that when the turbocharger rotates at a low speed (the oil supply is small at this time), the oil is not stored in the empty space C on the back surface of the compressor rotor 31. Is never leaked.

However, when the turbocharger rotates at high speed and the oil supply increases, the oil cannot be completely discharged from the passage a, and there is no oil outlet from the vacant chamber A, so that the vacant chamber A is filled with oil and finally A large amount of oil flows into the empty room B. As a result, oil cannot be completely discharged from the passage b, flows into the empty chamber C, and leaks out to the back surface of the compressor rotor 31.

4 to 7 show the details of the thrust bearing 34 according to the embodiment of the present invention. The characteristic point is that the holes 40 communicating with both end surfaces of the bearing 34 are formed in the upper portion of the thrust bearing 34. A groove 41 for discharging oil is formed on the contact surface side with the bearing housing 35 so as to communicate with the oil drain chamber D obliquely above the lower part of the sealing plate 36 from the hole 40.

Next, the operation will be described with reference to FIG. 2 and FIG.
When the amount of oil flowing into the interior is small, the air in the oil drain chamber D is introduced into the chamber A through the groove 41 through the hole 40 as shown in FIG. After that, the discharge to the empty room D is improved.

When the turbocharger rotates at a high speed and a large amount of oil accumulates in the vacant chamber A, the oil in the vacant chamber A is discharged from the hole 40 provided above the thrust bearing 34 as shown in FIG. Since the oil is discharged into the oil drain chamber D through the groove 41, the oil filled in the chamber A does not flow out to the chamber B.

8 to 12 show another embodiment of the thrust bearing of the present invention. In this case, the thrust bearing 34 'has
In addition to the hole 40 and the groove 41 communicating with both sides in the case of FIG. 5, a hole 40 'and a groove 41' communicating with both sides are provided.
0'is located at a position where the vertical height is low, the hole 40 is dedicated to the introduction of air, and the hole 40 'is dedicated to the discharge of oil. By dedicating holes 40 and 40 'for air and oil in this way, even if oil is flowing out of hole 40', hole 40
Since the air is introduced from the above, the discharge capacity of the oil discharged from the hole 40 'to the oil drain chamber D can be improved.

[Effect of device]

Since the present invention is configured as described in detail above,
When the turbocharger is running at low speed, the air in the oil drain chamber is introduced into the space formed between the thrust bearing and the sealing plate through the passage to promote the discharge of oil from the space to the oil drain chamber. You can When a large amount of oil flows into the empty chamber so that the oil flows into the empty chamber, the oil flowing into the empty chamber is discharged from the passage through the groove to the oil drain chamber.
It is possible to prevent oil from flowing into and leaking from the space to the back surface of the compressor rotor. Therefore, according to the present invention, there is no increase in mechanical loss as in the prior art, and since it is possible to deal with this by simply forming a hole in the thrust bearing, there is no increase in cost.

[Brief description of drawings]

FIG. 1 is a side sectional view of a thrust bearing portion of a supercharger showing an embodiment of the present invention, and FIGS. 2 and 3 are enlarged sectional views of an essential portion in FIG. 4 is a left side view of the thrust bearing showing the first embodiment of the present invention used in FIG. 1, FIG. 5 is a right side view of the same, FIG. 6 is a sectional view taken along line AA of FIG. 5, and FIG. Is a sectional view taken along the line BB in FIG.
The drawing is a left side view of a thrust bearing showing an embodiment different from that of FIG. 4, FIG. 9 is a right side view of the same, and FIG.
C sectional view, FIG. 11 is an E-E sectional view of FIG. 9, FIG. 12 is a D-D sectional view of FIG. 9, FIG. 13 is a side sectional view of a conventional turbocharger, and FIG. Fig. 13 is a left side view of the thrust bearing in Fig. 13, Fig. 15 is a right side view of the same, and Fig. 16 is a sectional view taken along line F-F in Fig. 15. Explanation of the main parts of the figure 30 …… Rotor shaft 31 …… Compressor rotor 32,33 …… Thrust bush 34 …… Thrust bearing 35 …… Bearing housing 36 …… Sealing plate 37 …… Seal ring 38 …… Oil passage 39… … Oil passage 40 …… Communication hole 40 ′ …… Other communication holes 41 …… Groove 41 ′ …… Groove

Claims (1)

[Scope of utility model registration request] 1. A rotor shaft 30 having a fixed compressor rotor.
The thrust bearing 34 that receives the thrust force of the rotor shaft, the thrust bush having a collar portion fixed to the rotor shaft 30, and the lubricating oil that is provided between the compressor rotor and the thrust bearing 34 and that is supplied to the thrust bearing 34. In a supercharger including a sealing plate, a cavity A formed between the thrust bearing 34, the sealing plate 36 and the rib portion of the thrust bush is provided, and a communication hole 40 communicating with the cavity is provided in the thrust bearing 34. A supercharger provided at an upper portion, which is provided with a passage 41 for communicating the communication hole and the oil drain chamber D, and the communication hole 40 is provided on an outer peripheral side of a flange portion of the thrust bush.