JPH02221635A - turbocharger turbine shaft - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to the structure of a turbine shaft of a supercharger.

[Conventional technology]

The turbine shaft of a conventional turbocharger has a support shaft supported by a bearing, an end connected to the opposite end of the turbine impeller mounting part, and a thrust shaft connected to the compressor impeller mounting part, which has a smaller diameter than the support shaft.・The collar and compressor impeller were installed in this order, and tightened with nuts.

In this way, the turbine shaft has a step between the supporting shaft and the mounting shaft of the compressor impeller, and this step prevents the thrust force of the turbine shaft from being received, thereby changing the axial mounting position of the turbine shaft and compressor impeller. I was trying to set it.

[Problem to be solved by the invention]

As mentioned above, in a turbocharger using a conventional turbine shaft, when the rotation speed reaches a high speed within the operating speed range, the step between the support shaft of the turbine shaft and the mounting shaft of the compressor impeller The amplitude of vibrations at nodes increases, making it difficult to reduce noise.

An object of the present invention is to provide a turbine shaft for a supercharger that can significantly reduce vibration and reduce noise.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a turbine impeller, a compressor impeller, a turbine shaft that fixes the turbine impeller and the compressor impeller at both ends, and a central portion of the turbine shaft that is fixed to each other through a bearing. A supercharger including a center hanging for supporting the turbine shaft, characterized in that a support part of the turbine shaft by the bearing and a mounting part of the compressor impeller have the same diameter, eliminating a step.

[Effect]

In the present invention, the diameter of the mounting shaft of the compressor impeller is made the same as the diameter of the support shaft, and there is no step part, so the amplitude of vibrations at the one step part can be significantly reduced, resulting in lower noise. can be achieved.

〔Example〕

FIG. 1 is a sectional view of a turbine shaft portion of a supercharger according to an embodiment of the present invention, and FIG. 2 is a sectional view of the compressor impeller shown in FIG. 1.

In these figures, 1 is a turbine impeller.

21 is a thrust collar 21A and a bag-shaped tightening nut 21B
31 is a center housing provided between both impellers 1 and 21;
Reference numeral 41 denotes a turbine shaft, which is composed of a mounting shaft portion 41B for the compressor impeller 21 having the same diameter as the support shaft portion 41A.

5 is a floating bush bearing supporting the turbine shaft 41;
Reference numeral 81 indicates a thrust metal fixed to the center housing 31.

In this way, the integrally oval compressor impeller 21 is attached to the mounting shaft portion 41B of the compressor impeller of the turbine shaft 41.
The mounting position in the axial direction is regulated by the end face of the tip of the mounting shaft portion 41B of the compressor impeller.

That is, in the turbine 1141 of the supercharger, the diameters of the supporting shaft portion 41A of the turbine impeller 1 and the mounting shaft portion 41B of the compressor impeller 21 are made equal to increase the rigidity thereof.

FIG. 3 shows a sectional view of a turbine shaft portion of a supercharger using a rolling bearing according to another embodiment of the present invention.

In this figure, 1 is a turbine impeller, 22 is a compressor impeller, 32 is a center housing provided between the turbine impeller 1 and the compressor impeller 22, and 4 is a center housing provided between the turbine impeller 1 and the compressor impeller 22.
Reference numeral 2 denotes a turbine shaft, which forms a mounting shaft portion 42B for the compressor impeller 22 having the same diameter as the support shaft portion 42A. 9
is an oil damper provided in the center housing 32; 6 is a rolling bearing supported by the oil damper 9; 11 is a spring for applying preload in the thrust direction; 82 is a thrust plate that presses the rolling bearing;
10 indicates the thrust collar. And the turbine shaft 4
Thrust shaft 42B of compressor impeller 2
The collar 10 and the compressor impeller 22 are mounted in this order, and the mounting position in the axial direction is regulated by the tightening nut 7. This embodiment also operates in the same manner as the embodiment shown in FIG. 1, and can obtain similar effects.

FIG. 4 is a diagram showing a comparison of the vibration characteristics of the turbine shaft of the present invention and a conventional turbine shaft, where the horizontal axis shows the rotational speed of the supercharger and the vertical axis shows the vibration amplitude.

In this figure, the solid line shows the vibration characteristics of the turbine shaft according to the present invention, the broken line C shows the vibration characteristics of the conventional turbine shaft, and C' shows the amplitude of the conventional vibration in the high-speed rotation range used. show.

From this figure, it can be seen that the turbine shaft vibration amplitude machine in which the support shaft and the compressor impeller mounting shaft of the present invention have the same diameter has a stepped portion between the support shaft and the compressor impeller mounting shaft. It can be seen that the amplitude is reduced in the high-speed rotation range of the rotational speed range in use compared to the conventional one (the amplitude peak indicated by C' in the conventional one disappears).

In the above embodiment, the support shaft of the turbine shaft and the mounting shaft of the compressor impeller have the same diameter, which increases the rigidity of the entire turbine shaft. ) can be significantly reduced.

〔Effect of the invention〕

According to the present invention, the rigidity of the turbine shaft can be increased,
It is possible to significantly reduce the amplitude of vibration in the high-speed rotation range within the operating rotation speed range, and it is possible to achieve low noise.

[Brief explanation of the drawing]

1@ is a sectional view of one embodiment of the present invention, FIG. 2 is a sectional view of the compressor impeller shown in FIG. 1, 3rd wi is a sectional view of another embodiment of the present invention, and FIG. FIG. 3 is a diagram showing a comparison of the vibration characteristics of a conventional turbine shaft. 1... Turbine impeller, 21.22... Compressor impeller, 31.32... Center housing, 41
゜42...Turbine shaft, 5...Floating bush bearing.

Claims (1)

[Scope of Claims] 1. A turbine impeller, a compressor impeller, a turbine shaft that fixes the turbine impeller and the compressor impeller at both ends, and a center that supports the center portion of the turbine shaft via a bearing. - A turbine shaft of a supercharger including a housing, wherein a support portion of the turbine shaft by the bearing and a mounting portion of the compressor impeller have the same diameter to eliminate a step. 2. In a turbocharger turbine shaft supported by a bearing supported by an oil damper provided in a center housing and having a compressor impeller attached to one end thereof, the turbine shaft is supported by the bearing. A turbine shaft for a supercharger, characterized in that the diameter of the part and the mounting part of the compressor impeller are the same and there is no step. 3. A thrust collar, a compressor impeller, and a tightening nut are integrally formed on a mounting shaft portion of the compressor impeller of the turbine shaft, and the shaft is positioned in the axial direction. turbocharger turbine shaft.