JPS6313361Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shaft structure of a turbocharger. Figure 1 shows a cross-sectional view of a typical turbocharger, in which a turbine impeller 2 is disposed within a turbine housing 1 to which exhaust gas from the engine is supplied.
and a compressor impeller 4 disposed in a compressor housing 3 connected to the intake passage of the engine are integrally coupled via a shaft 5, and metals 61 and 62 that receive radial loads are attached to the shaft. ing. The surroundings of the metals 61 and 62 that receive the radial load are always covered with lubricating oil, and the shaft 5 rotates while floating and sliding in the lubricating oil. On the other hand, since the turbine impeller 2 is given rotational force by the pressure of exhaust gas, it is exposed to high heat. This high heat is transmitted to the compressor impeller 4 side via the shaft 5. At this time, the lubricating oil flowing around the metals 61 and 62 becomes high in temperature, promoting deterioration of the lubricating oil, and in the worst case, problems such as metal seizure may occur.

In view of the above, the present invention aims to prevent deterioration of lubricating oil and metal seizure without significantly changing the structure of a turbocharger. In addition, another object of the present invention is to provide a turbocharger that can reduce the inertia weight of the rotating parts of the turbocharger and perform efficient supercharging.

This invention will be explained below with reference to embodiments of the drawings. FIG. 2 is a sectional view of a main part showing a first embodiment of the present invention. In the figure, 5' is a hollow member formed in the shape of a hollow tube, and a cylindrical reinforcing member 9 is fitted by press-fitting or the like at the position where the metal is mounted.

A connecting portion 81 of the impeller fixing shaft 8 for attaching the compressed impeller is fitted into one end of the hollow member 5' and is fixed by brazing or friction bonding, and the connecting portion 81 is attached to the metal 61. It is constructed in such a size that it reaches the mounting position, and also has the function of a reinforcing member.

Further, a connecting portion 21 formed on the turbine impeller 2' is fitted into the other end of the hollow member 5' and fixed by brazing, friction bonding, or the like.

Note that the hollow portion 7 of the shaft 5 configured as described above may be filled with a heat insulating material such as glass wool during assembly.

As described above, according to this embodiment, since the shaft 5 is constituted by the hollow member 5', the hollow portion 7 formed by the hollow member 5' has low heat transfer.
Therefore, the heat transfer from the exhaust gas to the compressor impeller 4 side, which is received by the turbine impeller 21, is significantly reduced. Metal 6
It is possible to prevent the deterioration of the lubricating oil flowing through the pipes 1 and 62 and the seizure of the metal.

In addition, by forming the shaft 5 with a hollow member 5' and inserting reinforcing members into the portions that receive radial loads, the weight of the shaft 5 can be reduced while maintaining the strength of the shaft 5 at the same level as conventional ones. As a result, the inertial weight of the rotating parts of the turbocharger is reduced, and efficient supercharging can be performed.

Figure 3 shows a second embodiment of the present invention, in which the hollow member is divided into two members 51'' and 52'', and both hollow members 51'' and 52'' are reinforced at the part where the metal 62 is attached. They are connected by a member 9'. The reinforcing member 9' has an outer diameter at the center that is the same as the outer diameter of the hollow members 51'' and 52'', and an outer diameter at both ends that is approximately the same as the inner diameter of the hollow members 51'' and 52''. The small diameter portions 91'' and 92'' are fitted into the hollow members 51'' and 52'', respectively, and fixed by brazing or friction bonding, etc., so that both the hollow members 51 ” and 52” are connected.

Further, a connecting portion 81' of the fixed impeller fixed shaft 8' connected to the hollow member 51'' is also provided with a small diameter portion 82' having an outer diameter that is approximately the same as the inner diameter of the hollow member 51''. The small diameter portion 82' is fitted into the hollow member 51'' and fixed by brazing or friction bonding, and in this case, the metal 61 is fitted around the outer periphery of the connecting portion 81'.

With this structure, the shaft 5 is formed with the hollow part 7, and the same effect as the first embodiment of the present invention shown in FIG. ″, so
The effect of shortening the time required for inserting the reinforcing member 7 and improving the ease of assembly can be obtained.

As described above, according to the present invention, the shaft of the turbocharger is formed of a hollow member, and a reinforcing member is fitted into the metal attachment part, so that it is possible to avoid major changes to the structure of the turbocharger. This prevents problems such as lubricating oil deterioration and metal seizure without reducing the strength of the shaft, and also reduces the inertia of the rotating parts of the turbocharger.
This allows efficient supercharging.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional turbocharger, Fig. 2 is a sectional view of main parts showing the first embodiment of the present invention, and Fig. 3 is a sectional view of main parts showing the second embodiment of the invention. be. 2, 2', 2''...Turbine impeller, 4...Complex impeller, 5...Shaft, 7...Hollow portion, 9...Reinforcement member.

Claims (1)

[Claims for Utility Model Registration] (1) A turbine impeller disposed in a turbine housing to which exhaust gas from an engine is supplied and a compressed impeller connected to an intake passage of the engine are integrally coupled via a shaft. In the turbo supercharger in which the shaft is equipped with a metal that receives a radial load, the shaft is formed of a hollow member, and a reinforcing member is inserted into the part where the metal is attached. Machine shaft structure. (2) The shaft structure according to claim 1 of the utility model registration, characterized in that the hollow member is divided into a plurality of parts, and the hollow members are connected to each other via a reinforcing member.