JPS5868521A - Impeller of fluid coupling - Google Patents

Abstract

PURPOSE:To reduce the maximum stress of blade root sections, and to increase transmission force by disposing blades so as to generate bending stress generated by a working fluid and bending stress in the opposite direction in the impeller manufactured by arranging a large number of the blades to a core plate fixed to a shaft. CONSTITUTION:With the fluid coupling, a working chamber to which the working fluid is supplied is formed between an impeller connected to an input shaft and a runner impeller connected to an output shaft, and power from the input shaft is transmitted to the output shaft through said both impellers. The impeller 7 is formed by disposing a large number of the rectilinear blades 8 to the core plate 9 fixed to the input shaft 1. In this case, the rectilinear blades 8 are arranged so as to be displaced to a shaft core O so that bending stress generated by the working fluid and bending stress in the opposite direction are generated. Accordingly, bending stress generated by the working fluid and bending stress generated by the displacement of the rectilinear blades 8 are mutually denied, and the maximum stress generated in the root sections of the rectilinear blades 8 can be reduced.

Description

[Detailed description of the invention] The present invention relates to an impeller for a fluid coupling.

Figure 1 shows the structure of a conventional fluid coupling, where the input shaft 1
When the impeller impeller is rotated with working fluid supplied to the working chamber 5 formed by the impeller impeller 2 connected to the output shaft 3 and the runner impeller 4 connected to the output shaft 3, the working fluid is transferred to the launch impeller due to centrifugal force. 4 and the kinetic energy of the working fluid is given to the launch impeller, so power from the input shaft 1 is transmitted to the output shaft 3 via the impeller impeller 2 and the runner impeller 4.

2 and 3 show the structure of an impeller impeller 2 or launch impeller 4 (hereinafter described as impeller impeller 2), in which a core 5 is fixed to the input shaft 1 or the output shaft 3.
A large number of straight blades 6 are attached radially at equal intervals on the side surface of the blade. That is, the straight blade 6 is arranged toward the rotation axis 0.

FIG. 4 is a diagram for explaining the force state generated in the impeller impeller 2 when working fluid is applied to the impeller impeller 2. FIG.

In FIG. 4, when the working fluid is applied to the impeller impeller 2 which is in the first rotation state, the impeller impeller 2 tries to push out the working fluid. At this time, the straight blades 6 of the impeller impeller 2 receive a force from the IElIf& body in the direction of the arrow shown in the figure, that is, a force that tends to bend the straight blades 6. Also,
The linear blades 6 of the impeller impeller 2 receive a force in the direction of arrow B in the figure, that is, a force that attempts to pull the linear blades 6 due to centrifugal force due to the impeller impeller 2's own weight. At this time, the stress distribution generated in the straight blade 6 is shown in FIG.

In recent years, the transmission power and speed of fluid couplings have been increasing further, and the bending force or tensile force is also increasing accordingly.

By the way, in the structure of the conventional impeller impeller 2, as shown in FIG.
If bending stress (solid line in the figure) is applied even if the value is less than the allowable limit value (double chain W shown in the figure), the maximum stress may exceed the allowable limit value of the material, especially at the root of the straight blade 6, and the transmitted power may be There were problems in increasing the number and speeding up the process.

In view of the above-mentioned points, the present invention aims to provide an impeller for a fluid coupling that makes it possible to increase the transmission power and increase the speed. In the impeller of the fluid coupling, the blades are arranged so as to generate a bending stress in a direction opposite to the bending stress caused by the working fluid.

An embodiment of the present invention will be described below with reference to the drawings.

Items refer to the same parts.

7 is an impeller impeller, 8 is a large number of straight blades joined to the side surface of the core root 9 of the impeller impeller 7, and this 1! [i1 The blade 8 is arranged so as to be offset from the rotation axis 0. (Displacement angle α shown) When the straight blades 8 are arranged in this manner, the bending stress generated by the working fluid and the bending stress generated by the deviation K of the straight blades 8 cancel each other out.

In the impeller impeller 7 configured as described above, when the impeller impeller 7 is rotated in the direction of the arrow shown in the figure without applying working fluid, the linear blades 8 tend to extend radially along the direction of centrifugal force. , both hooked surfaces ga of the straight blade 8,
Stress in the direction of the arrow shown in the figure is generated in each of the parts 8b. At this time, a tensile stress 4F- is generated on one side surface 8a of the straight blade 8 as shown in FIG.
A compressive stress σ is generated in b.

Next, when the impeller impeller 7 is rotated in the direction of the arrow shown with the working fluid added, the linear blades 8 of the impeller impeller 7
As shown in FIG. 10, since a force is applied from the working fluid in the direction of the arrow in the figure, stress in the direction of the arrow in the figure is generated on one side surface 8a of the straight blade. For this reason, the straight blade 8
On one side surface 8a, as shown in FIG. 11, the tensile stress σ generated when no working fluid is applied and the compressive stress σ generated when the working fluid is applied cancel each other out. Further, on the other side surface 8b of the straight blade 8, stress occurs in the opposite direction to the one side surface 8a,
As before, they cancel each other out.

As a result, a stress σ approximately equivalent to the centrifugal force due to the impeller impeller 7's own weight is generated in the straight blade 8.

Therefore, the maximum stress at the root portion of the straight blade 8 can be significantly reduced, so that it does not exceed the allowable limit value of the material as in the conventional case.

According to the fluid coupling of the present invention, the blades constituting the impeller are
Since the bending caused by the working fluid is arranged so as to generate bending stress in the opposite direction to the stress, the maximum stress that conventionally occurs at the blade root can be significantly reduced, making it possible to increase the transmitted power and increase the speed. becomes.

In one embodiment of the present invention, an impeller impeller has been described, but the same effect can be obtained when applied to a launch impeller.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the structure of a fluid coupling, Figs. 2 and 3 show the structure of a conventional impeller, Fig. 2 is a front view, and Fig. 3 is 3-3 in Fig. 2. A line cross-sectional view, Figure 4 is a diagram to explain the state of force applied to the blades when a working fluid is added to a conventional impeller and it is rotated, and Figure 5 shows the stress distribution that occurs in the conventional impeller. Figure 6 is a diagram for explaining the relationship between the stress generated in a conventional impeller and the allowable limit value of the material, Figure 7 is a diagram showing the mounting position of the blade in the impeller of the present invention, and Figure 8 9 is a diagram for explaining the force state that occurs when the impeller of the present invention is rotated without applying a working fluid, FIG. 9 is a diagram showing the stress distribution that occurs in the force state of FIG. 8, and FIG. The figure shows the stress distribution that occurs in the impeller when a working fluid is added to the impeller of the present invention and the blade is rotated. Figure 11 shows the case where a working female body is not added to the impeller of the present invention and when a working fluid is added to the impeller. FIG. 3 is a diagram showing the stress distribution that occurs on one side of the blade when the blade is heated. 1...Input shaft, 3...Output shaft, 5...Working chamber, 7
...Impeller, 8...Straight blade, 9...Core plate agent, patent attorney Toshiyuki Usuda, -- (P゛1st mouth 2nd mouth 3 days old 10th concave 2;F 5th;t7( 21 years old 3 concave

Claims (1)

[Claims] 1. In an impeller of a fluid coupling in which a large number of blades are arranged on a core fixed to a rotating shaft, bending of the blades caused by a working fluid causes stress, and bending in the opposite direction causes stress. An impeller of a fluid coupling characterized by being arranged so as to force the impeller. 2. The impeller for a fluid coupling according to claim 1, wherein the blades are arranged approximately offset from the rotation axis.