JP2924363B2 - Water-cooled bearing housing structure for turbocharger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-cooled bearing housing structure for a turbocharger, and to improve the cooling efficiency without changing the mounting conditions such as the arrangement of inlet and outlet of cooling water. .

[0002]

2. Description of the Related Art One of superchargers is an exhaust turbine supercharger (turbocharger), which rotates a turbine by using the energy of exhaust gas of an engine and drives a compressor mounted on a turbine shaft. By supercharging the intake air, the output performance of the engine is improved.

There are various types of this turbocharger. In general, a turbocharger for a vehicle supports a central portion of a turbine shaft with bearings, and arranges a turbine and a compressor at both ends of the turbine shaft. The configuration is, for example, as shown in FIG.

The turbocharger 1 has three housings 2, 3, 4. A turbine 6 is disposed at one end of a turbine shaft 5 in the turbine housing 2, and the turbine 6 is disposed in a compressor casing 4 of the turbine shaft 5. The compressor 7 is arranged at the other end, and the center of the turbine shaft 5 is rotatably supported by the bearing 8 of the bearing housing 3 in the middle.

The bearing portion 8 of the bearing housing 3 includes, for example, floating metals 9 and 1 for two journals.
0 is disposed on the turbine side and the compressor side, and further, a thrust metal 11 is provided on the compressor side.
A lubrication port 12 is formed in the upper part of the bearing housing 3 for lubrication of the bearing portion 8, and lubricating oil is supplied to each of the metals 9 to 11 by an oil passage 13, and an oil drain hole 14 and a The oil is collected outside the turbocharger 1 from the oil discharge port 15. Further, the turbocharger 1 is provided with an oil seal structure 16 for sealing a lubricating oil for lubricating the bearing portion 8, and an oil hole 17 is fitted on the turbine shaft 5 and provided on the outer periphery thereof.
While the large and small piston rings 18 and 19 are mounted in the two grooves, a seal plate 20 is fixedly mounted on the bearing housing 3, and the piston rings 18 and 19 are slid on the inner peripheral surface of the seal plate 20. .

In such a turbocharger 1, it is necessary to protect the bearing portion 8, particularly the metal 9 on the turbine 6 side, from heat such as exhaust gas transmitted to the bearing housing 3 in order to increase the thermal load and improve reliability. .

For this reason, cooling is performed by flowing cooling water (Japanese Patent Publication No. Sho 62-17095).
6, an annular cooling water jacket 21 is formed around the turbine shaft 5 on the turbine side of the bearing housing 3, and a cooling water inlet 22 and a cooling water outlet are formed on both sides of the axial center of the bearing housing 3. 23, and the cooling water supplied from the cooling water inlet 22 is diverted up and down from the side of the cooling water jacket 21 to flow therethrough, and guided to the cooling water outlet 23 from the side opposite to the cooling water jacket 21. It cools while discharging.

In the supercharged internal combustion engine disclosed in Japanese Utility Model Publication No. 64-3786, an annular cooling water jacket is formed around the turbine shaft in the same manner as in the above-described embodiment, and the cooling water jacket is formed. The inlet and outlet of the cooling water are changed from those in the above example, and the cooling water flows in from below the cooling water jacket and is diverted to both sides, and the cooling water is discharged from above the symmetrical position and cooled.

[0009]

In such a cooling structure of the bearing housing 3, an annular cooling water jacket 21 is formed around the entire periphery of the turbine shaft 5 so that cooling water flows therethrough. The cooling water flowing through the inside is divided into two semicircles, and the flow velocity is reduced and the flow rate is reduced by half. Therefore, there is a problem that the supply amount of the cooling water must be increased. The present invention has been made in view of the problems of the related art, and has a water-cooled bearing housing structure of a turbocharger capable of improving cooling efficiency without changing mounting conditions such as arrangement of inlet and outlet of cooling water. It is intended to provide.

[0010]

In order to solve the above-mentioned problems, a water-cooled bearing housing structure of a turbocharger according to the present invention has a center portion of a turbine shaft provided with a turbine and a compressor at both ends provided in a bearing housing. In a supercharger rotatably supported by bearings, a cooling water jacket in which a total amount of cooling water flows in one direction around substantially the entire circumference of the turbine shaft with a top partition wall interposed between the bearing housings, While forming the inlet and outlet of the cooling water in the bearing housing at substantially the same height on both sides of the turbine shaft,
An inlet communication passage communicating the inlet of the cooling water with one side of the top partition wall of the cooling water jacket, and an outlet communication passage communicating the outlet of the cooling water with the other side of the top partition wall of the cooling water jacket. It is characterized by being formed in a bearing housing.

[0011]

According to the water-cooled bearing housing structure of the turbocharger, the cooling water jacket formed on the bearing housing is formed in a loop shape that surrounds substantially the entire circumference of the turbine shaft with the top partition wall interposed therebetween. An inlet and an outlet for cooling water are formed in the bearing housings having substantially the same height on both axial sides, and the inlet of the cooling water is communicated with one side of a top partition wall of the cooling water jacket through an inlet communication passage. The water outlet communicates with the other side of the top partition wall of the cooling water jacket through an outlet communication passage, and the cooling water supplied through the cooling water inlet and the inlet communication passage is formed into a loop-shaped cooling water jacket. The entire amount is flowed in one direction from one end, and cooling is performed while discharging from the outlet communication passage and the cooling water outlet.

As a result, the flow rate of the cooling water is substantially the same in each part of the cooling jacket, and the cooling efficiency can be improved. Therefore, there is no need to change the inlet / outlet of the cooling water formed in the bearing housing. To ensure the mounting conditions.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. 1 to 3 relate to an embodiment of a water-cooled bearing housing structure of a supercharger according to the present invention. FIG. 1 is an overall longitudinal sectional view, and FIG. 2 is a sectional view taken along a line AA in FIG. C) Sectional view, FIG. 3 is a view on arrow B in FIG. The same parts as those of the turbocharger described with reference to FIG.

The water-cooled bearing housing structure 30 of the turbocharger
As shown in FIGS. 1 to 3, a loop-shaped cooling water jacket 31 is formed on the turbine side of the bearing housing 3 around substantially the entire circumference of the turbine shaft 5. That is, the cooling water jacket 31 has a shape in which the upper portion is partitioned by a top partition wall 32 that is integral with the bearing housing 3, and has a loop shape in which an annular part is closed.

In order to supply and discharge the cooling water to and from the cooling water jacket 31, the conventional turbocharger 1 described above is used.
Similarly to the above, a cross-flow type (a type in which cooling water flows in and out of the turbine shaft 5 orthogonally) is formed in which a cooling water inlet 33 and a cooling water outlet 34 are formed on both sides of the axial center portion of the bearing housing 3. In this case, the conditions for mounting on the engine as the turbocharger 1 are the same.

The cooling water inlet 33 and the top partition 32
Between the cooling water outlet 31 and the end of the cooling water jacket 31 on the other side of the top partition wall 32 with the inlet communication passage 35 formed in the bearing housing 3. The parts are communicated with each other by an outlet communication passage 36 formed in the bearing housing 3. The inlet communication passage 35 and the outlet communication passage 36 formed in the bearing housing 3.
1 is arranged so as to be inclined with respect to the turbine shaft 5 as shown in FIG. 1. In particular, the inlet communication passage 35 approaches the oil passage 13 between the lubricating oil supply port 12 and the metal 9, and The oil and the cooling water are formed so that heat can be exchanged in an AC state, and are also used for cooling the lubricating oil to the metal 9 on the turbine side. Since the configuration of the other turbocharger 1 is the same as that of FIG. 4 already described, the description thereof will be omitted.

According to the water-cooled bearing housing structure 30 of the supercharger configured as described above, cooling is performed as follows. A part of the cooling water of the engine cooling system is
Is supplied to the turbocharger 1, the cooling water flows in the horizontal direction at right angles to the turbine shaft 5, and then flows into the inlet communication passage 35.
Gently ascends toward the turbine side through
On the way, it flows into the end of the cooling jacket 31 on one side of the top partition wall 32 while cooling the lubricating oil by approaching the oil passage 13 for the lubricating oil.

The entire amount of the cooling water flowing from the end of the cooling jacket 31 flows in the cooling jacket 31 in a loop shape, while cooling the bearing housing 3, the bearing portion 8, and the like.
It reaches the end of the cooling jacket 31 on the other side of the top partition wall 32.

The cooling water thus flowing in one direction in the cooling jacket 31 gently descends toward the compressor via the outlet communication passage 36, flows in the horizontal direction perpendicular to the turbine shaft 5, and flows out of the cooling water outlet 34. It is discharged out of the turbocharger 1.

As described above, since the entire amount of the cooling water flows in one direction from one end of the cooling jacket 31 to the other end, the flow rate of each part of the cooling jacket 31 is the same,
The flow rates are also substantially the same, and the cooling efficiency is improved as compared with the case where a conventional annular cooling jacket is used.

The top partition wall 32 of the cooling water jacket 31 is made very thin as shown in FIG. 2, so that the entire circumference of the turbine shaft 5 can be cooled uniformly.

Further, when the cooling water in the cooling water jacket 31 is boiled after the engine is stopped,
When the engine is operated and the cooling water is supplied, the flow rate of the cooling water flowing in the cooling water jacket 31 is larger than that of the conventional cooling water, and the flow velocity is high, so that the boiled air is easily discharged to the outside by the cooling water. be able to.

Further, the cooling water inlet 33 and the cooling water outlet 34, which only have to communicate the cooling water jacket 31 with the inlet communication passage 35 and the outlet communication passage 36, can be freely arranged, and are arranged at the same position as the conventional turbocharger 1. By doing so, there is no need to change the mounting conditions on the engine.

Further, by changing the arrangement of the inlet communication passage 35, the lubricating oil supplied to the bearing 8 can be cooled. In the above-described embodiment, a supercharger for an automobile has been described as an example. However, the present invention is not limited to this and can be widely applied to a water-cooled bearing housing structure of another supercharger. Further, changes may be made to each component without departing from the scope of the present invention.

[0025]

According to the water-cooled bearing housing structure of the turbocharger according to the present invention, as described above in detail with one embodiment, the cooling water jacket formed on the bearing housing is provided with the turbine shaft sandwiched between the top partition walls. And a cooling water inlet and outlet are formed in the bearing housing at substantially the same height on both sides of the turbine shaft, and the cooling water inlet is formed at the top of the cooling water jacket. The cooling water outlet communicates with one side of the partition wall at the inlet communication passage, and the cooling water outlet communicates with the other side of the top partition wall of the cooling water jacket at the outlet communication passage. The cooling water supplied through the cooling water jacket is allowed to flow in one direction from one end of the loop-shaped cooling water jacket to cool the inside of the bearing housing while being discharged from the outlet communication passage and the cooling water outlet. Therefore, the flow rate of the cooling water flowing in the entire amount in one direction is substantially the same in each part of the cooling jacket,
The cooling efficiency can be improved as compared with the case where a cooling jacket is provided on the entire circumference.

Further, there is no need to change the inlet / outlet of the cooling water formed in the bearing housing, and it is possible to ensure the same mounting conditions for the engine as before. Furthermore, since the amount of the cooling water flowing in the cooling water jacket is large and the flow velocity is high, the siphon effect can be used, and the boiled air is hardly trapped.

[Brief description of the drawings]

FIG. 1 is an overall vertical sectional view of a water-cooled bearing housing structure of a turbocharger according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG. 1 (CC in FIG. 3) according to the embodiment of the water-cooled bearing housing structure of the turbocharger of the present invention.

FIG. 3 is a view taken in the direction of arrow B in FIG. 2 according to the embodiment of the water-cooled bearing housing structure of the supercharger of the present invention.

FIG. 4 is an overall longitudinal sectional view of a conventional water-cooled bearing housing structure of a turbocharger.

FIG. 5 shows a conventional water-cooled bearing housing structure of a supercharger.
FIG. 7 is a sectional view taken along line AA (CC in FIG. 6).

FIG. 6 shows a conventional water-cooled bearing housing structure of a turbocharger.
FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Turbocharger (supercharger) 2 Turbine housing 3 Bearing housing 4 Compressor housing 5 Turbine shaft 6 Turbine 7 Compressor 8 Bearing part 9,10 Floating metal 11 Thrust metal 12 Oil supply port 13 Oil passage 14 Oil hole 15 Oil discharge port 30 Water-cooled bearing housing structure of turbocharger 31 Cooling water jacket 32 Top partition wall 33 Cooling water inlet 34 Cooling water outlet 35 Inlet communication passage 36 Exit communication passage

Claims (1)

(57) [Claims] 1. A supercharger in which a turbine shaft provided with a turbine and a compressor at both ends thereof is rotatably supported by a bearing provided in a bearing housing, said turbocharger having a top partition wall sandwiched between said bearing housing. A cooling water jacket is formed around substantially the entire circumference of the turbine shaft so that the entire amount of cooling water flows in one direction, and an inlet and an outlet of the cooling water are provided to the bearing housing at substantially the same height on both sides of the turbine shaft. On the other hand, an inlet passage communicating the inlet of the cooling water with one side of the top partition wall of the cooling water jacket and an outlet passage communicating the outlet of the cooling water with the other side of the top partition wall of the cooling water jacket. A water-cooled bearing housing structure for a turbocharger, wherein a passage is formed in the bearing housing.