JP2587524B2 - Coreless torque converter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a coreless torque converter that does not have a core at a portion where blades are gathered.

(Prior Art) Conventionally, as a coreless torque converter, for example,
The one described in SAE Paper 861213 is known.

As shown in FIG. 5, this conventional source has three elements, a pump impeller 01, a turbine runner 02, and a stator 03, and a three-element two-phase without a core in a portion where these blades are assembled. A coreless torque converter called a mold is shown.

(Problems to be Solved by the Invention) However, in such a coreless torque converter, a flow corresponding to a core of a torque converter applied to a general passenger is restricted to form a flow path. Because there are no members, the center of the vortex of the circulating flow is biased toward the turbine runner side, and the stall torque ratio and efficiency are lower than the torque converter with core, making it difficult to apply to small displacement vehicles. There is a problem that the fuel consumption performance deteriorates under the running conditions in which the above is repeated.

The present invention has been made in view of the above-described problems. In a coreless torque converter that does not have a core in a portion where each blade gathers, the torque ratio and the efficiency, etc. are improved by changing the shape in terms of cost. It is an object to improve torque converter characteristics.

(Means for Solving the Problems) In order to solve the above problems, in the coreless torque converter of the present invention, the axial size of the turbine runner is set shorter than the axial size of the pump impeller.

That is, in a coreless torque converter having three elements of a pump impeller, a turbine runner, and a stator and having no core at a portion where these blades are gathered, the axial dimension of the turbine runner is changed to the axial dimension of the pump impeller. It is characterized by being set shorter.

Preferably, the axial dimension of the turbine runner is set in a range of 0.5 to 0.9 times the axial dimension of the pump impeller.

(Operation) When operating the coreless torque converter mounted on a passenger car, etc., the axial dimension of the turbine runner is set shorter than the axial dimension of the pump impeller. As a result, the center of the vortex of the circulating flow moves toward the pump impeller.

That is, when the axial dimension of the turbine runner and the axial dimension of the pump impeller are set to be the same, the center of the vortex of the circulating flow is biased toward the turbine runner side, whereas the center of the vortex of the circulating flow is By moving to the pump impeller side, it approaches the portion where the blades are gathered.

As a result, the oil circulating inside easily flows out from the trailing edge of the stator, the flow of the oil passing through the upper end of the stator and flowing into the pump impeller or the turbine runner is suppressed, and the stator works effectively.

Embodiment First, the configuration will be described.

FIG. 1 is a sectional view showing a coreless torque converter according to an embodiment.

The coreless torque converter according to the embodiment has a pump impeller 2 coupled to a converter cover 1 to which an engine driving force is input, and is disposed at a position facing the pump impeller 2, and a transmission input shaft (not shown) is connected to a turbine hub 3.
And a stator 6 which is disposed at an inner diameter portion interposed between the pump impeller 2 and the turbine runner 4 and is provided in a case (not shown) via a one-way clutch 5. Have each of these wings 2,
The part where 4,6 gathers has only a wing tip close to each other, and has no core.

The pump impeller 2 has exactly the same shape as that used in the conventional coreless torque converter shown in FIG.

The turbine runner 4 is designed based on the turbine runner used in the conventional coreless torque converter shown in FIG. 5, and is formed by crushing at a constant ratio in the axial direction.

The stator 6 is designed on the basis of the stator used in the conventional coreless torque converter shown in FIG. 5, and has a shape corresponding to the shape change of the turbine runner 4 in the left half of the drawing facing the turbine runner 4. Is formed by crushing at a constant ratio.

The stator 6 has a larger number of stator blades than the case of FIG. 5 because the blade area per blade is reduced.

By changing the turbine runner shape, the turbine runner 4
And the wing portion axial dimension L, except for the shell portion of the set shorter than the blade portion axial dimension L ₀ except the shell portion of the pump impeller 2.

 Next, the operation will be described.

It can be said that the coreless torque converter is a variation of the fluid coupling in which only the pump impeller and the turbine runner are opposed to each other in view of its structure, and it is considered that the flow of the internal fluid also shows a flow similar to that of the fluid coupling.

Already published "Design of Fluid Power Transmission Equipment" (Toshio Ishihara and others; 1
According to Fig. 2 ・ 11 on page 23 of Ohmsha in 967)
In the fluid coupling, the center of the vortex of the circulating flow is biased toward the turbine runner at both the medium speed ratio and the low speed ratio. Note that a situation where the liquid phase and the gas phase are separated at a high speed ratio does not occur in the case of a normal torque converter (including a coreless type) because the inlet pressure is set to about 4 kg / cm ² .

Therefore, in the case of a coreless torque converter as shown in FIG. 5, a circulation flow as shown in the flow pattern of FIG. 2 is obtained by analogy with the circulation flow in the fluid coupling. That is, a substantial part of the flow flowing into the stator passes through the upper end of the stator and flows into the pump impeller or the turbine runner. This causes the torque ratio and efficiency to be low.

On the other hand, in the coreless torque converter of the embodiment,
Since the blade part axial dimension L of the turbine runner 4 is set shorter than the blade part axial dimension L _O of the pump impeller 2, the axial dimension of the turbine runner 4 is reduced (L-L _O ). Then, the center of the vortex of the circulation flow moves to the pump impeller 2 side. That is, when the axial dimension of the turbine runner and the axial dimension of the pump impeller are set to be the same, the center of the vortex of the circulating flow is biased toward the turbine runner as shown in FIG. The center of the vortex of the circulating flow moves toward the pump impeller 2 to approach the portion where the blades are gathered, and the flow pattern also becomes as shown in FIG.

As a result, the oil circulating inside easily flows out from the trailing edge of the stator 6, and the flow flowing through the upper end of the stator 6 and flowing into the pump impeller 2 or the turbine runner 4 is suppressed, and the stator 6 is effectively made. work.

As described above, in the coreless torque converter of the embodiment, the following effects can be obtained.

Since the axial dimension of the turbine runner 4 is set shorter than the axial dimension of the pump impeller 2, it is possible to improve the torque converter characteristics such as torque ratio and efficiency while changing the shape in a cost-effective manner without increasing the number of parts. I can plan.

Incidentally, Fig. 4 shows the performance test results of the coreless torque converter with the turbine runner aspect ratio L / L _O (see Fig. 1) changed. The L / L _O = 1.0 compared with the conventional structure. / L
_It can be seen that in the case of the embodiment structure in which _{O 2} = 0.9 and L / L _O = 0.8, the torque ratio and the efficiency are improved.

As a result, it can be applied to vehicles with small displacement,
The power performance and fuel efficiency of the applied vehicle are improved.

The difference between the axial dimension of the turbine runner 4 and the axial dimension of the pump impeller 2 is achieved by flattening the turbine runner 4 and changing the shape of the stator 6 accompanying the flattening. Does not require a design change with the conventional shape, and is advantageous in terms of design and manufacturing costs.

Although the embodiments have been described with reference to the drawings, the specific configuration is not limited to the embodiments.

For example, the embodiment shows an example in which the difference between the axial dimension of the turbine runner and the axial dimension of the pump impeller is achieved by flattening the turbine runner. Of course, both the turbine runner and the pump impeller may be changed in shape to obtain a difference in axial dimension.

In the embodiment, an example in which the axial dimension of the turbine runner is set to about 0.8 times the axial dimension of the pump impeller,
The magnification of the axial dimension is preferably set in a range of 0.5 to 0.9 times.

In other words, if the ratio is 0.9 times or more, sufficient movement of the center of the vortex of the circulating flow is not realized, and it is not expected to improve the torque ratio or efficiency.If the ratio is 0.5 times or less, the flow state of the turbine runner deteriorates, Or the number of blades increases, making production difficult.

Also in the case of the embodiment, the turbine runner aspect ratio L / L _{O is set} to 0.
It is good to set it in the range of 5 to 0.9 times.

(Effects of the Invention) As described above, according to the present invention, in a coreless torque converter having no core in a portion where each blade gathers, the axial direction of the turbine runner is Since the dimensions are set short, it is possible to obtain an effect that the torque converter characteristics such as torque ratio and efficiency can be improved by changing the shape which is advantageous in terms of cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a coreless torque converter according to an embodiment of the present invention, FIG. 2 is a view showing a flow pattern in a conventional coreless torque converter, and FIG. 3 is a flow pattern in a coreless torque converter of the embodiment. Figure 4
FIG. 5 is a characteristic diagram showing performance test results of the coreless torque converter, and FIG. 5 is a sectional view showing a conventional coreless torque converter. DESCRIPTION OF SYMBOLS 1 ... Converter cover 2 ... Pump impeller 3 ... Turbine hub 4 ... Turbine runner 5 ... One-way clutch 6 ... Stator L ... Tuner runner blade partial axial dimension L _O ... Pump impeller blade partial axial dimension

Claims (2)

(57) [Claims] 1. A coreless torque converter having three elements of a pump impeller, a turbine runner and a stator, and having no core at a portion where these blades are gathered, wherein the turbine runner has an axial dimension of the pump impeller. Coreless torque converter characterized by being set shorter than the axial dimension. 2. The coreless torque converter according to claim 1, wherein an axial dimension of the turbine runner is set in a range of 0.5 to 0.9 times an axial dimension of the pump impeller.