JPH11230303A - Torque converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a high transmission efficiency while maintaining a big transmission torque capacity which a coreless torque converter holds. SOLUTION: Blades 24, 28 of impellers 20, 25 have a curved surface which is constituted by aggregating line elements of a straight line tying the points which are set by a point set curve at shells 22, 26 side and a point set straight line drawn in parallel to a rotational axis in a space at cores 23, 27 side. The cores 23, 27 are formed such that a ratio of a passage area of the impellers 20, 25 relative to a circle area in which the outer diameter of the impellers 20, 25 is a diameter is within a range of 0.25 to 0.31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque converter used for a power transmission mechanism of a vehicle or the like.

[0002]

2. Description of the Related Art As a conventional torque converter, there is, for example, one shown in FIGS.
No. 7857).

This is called a coreless torque converter, and is connected to a pump (pump impeller) 2 which rotates integrally with a casing 1 connected to an engine crankshaft, and to an input shaft of a transmission via a turbine hub 3. (Turbine impeller) 4, and a stator 6 and the like disposed via a one-way clutch 5 rotatable only in one direction between an inlet of the pump 2 and an outlet of the turbine 4.

The pump 2 is rotated in synchronism with the rotation of the engine. A turbine 4 connected to a transmission is driven in accordance with the fluid pumped from the pump 2, and the fluid passing through the turbine 4 is passed through a stator 6. Circulates through pump 2. At the time of start, the stator 6 is fixed, changes the direction of the flow of the fluid circulating from the turbine 4 to the pump 2, and amplifies the torque by the torque received by the stator 6. After the coupling point, the stator 6 idles and becomes a fluid coupling.

[0005] This coreless torque converter is characterized in that the flow path area can be increased because there is no core, and therefore the transmission torque capacity is extremely large.

Further, this coreless torque converter is
The design of the blade 7 or 8 of the pump 2 or turbine 4 is defined by a group of straight lines formed by connecting a plurality of points on the shell 9 or 10 side and a plurality of points along the outer peripheral side of the stator 6 as shown in FIG. I have. That is, 2 is set to each of the shell 9 or 10 side point setting curve L ₁ and the set point on the rotation axis parallel to the edge of the outer peripheral blade 7 or parallel to the rotation axis along the side 8 of the stator 6 straight L ₂ It is defined to form a curved surface by assembling straight line elements connecting two points.

As a result, a proper curved surface of the blade can be ensured, the transmission torque capacity can be further increased, and the degree of freedom of design of the blade entrance angle and the blade exit angle, and the torque converter performance by the combination of these entrance angle and exit angle. It is possible to increase the degree of freedom in designing.

[0008]

However, this coreless torque converter has a large transmission torque capacity and a high degree of freedom in designing the torque converter performance. However, since there is no core, the transmission efficiency has a general core. Lower than torque converter. This is because a leakage flow is generated from the stator 6 to the pump 2 and from the pump 2 to the turbine 4 as shown in FIG. That is, the flow near the center greatly contributes to the torque transmission, that is, the torque capacity, but leaks out from the upper portion of the stator 6, so that the torque amplifying action of the stator 6 is reduced and the torque ratio is reduced. Therefore, the transmission efficiency is deteriorated. Therefore,
Deteriorating the fuel efficiency of the vehicle.

The present invention provides a torque converter in which a core is formed in a portion where the loss occurs, and a transmission efficiency is improved while maintaining a large transmission torque capacity and a high degree of design freedom of the coreless torque converter. It is intended to provide.

[0010]

According to a first aspect of the present invention, there is provided a pump impeller connected to an input shaft and defining a flow path between a shell fixed to a casing and a core via a blade, A turbine impeller that is disposed opposite to the pump impeller, is connected to the output shaft, and defines a flow path between the shell and the core via a blade; and a pump impeller inlet and a turbine impeller outlet. In a torque converter comprising a stator arranged via a one-way clutch that allows rotation only in one direction, a blade of at least one of the two impellers has a point setting curve on the shell side and a core side. Has a curved surface formed by collecting line elements of straight lines connecting two points set on each of the point setting lines drawn in parallel with the rotation axis in the space of The line element is A line element connecting a point arranged along the point setting curve from the peripheral end side and a point arranged on the point setting straight line toward the shell side, and a line element of the blade on the inner peripheral side from the point setting straight line is A line element connecting the points arranged along the point setting curve toward the inner peripheral end side of the blade and the points arranged on the point setting straight line in the opposite direction to the shell side, and the outer diameter of the impeller is The core is formed such that the ratio of the area of the flow path of the impeller to the area of the circle having a diameter is in the range of 0.25 to 0.31.

According to a second aspect of the present invention, there is provided a pump impeller which is connected to an input shaft and defines a flow path through a blade between a shell fixed to a casing and a core, and a pump impeller opposed to the pump impeller. The turbine impeller is connected to the output shaft and defines a flow path between the shell and the core via the blade, and only in one direction between the inlet of the pump impeller and the outlet of the turbine impeller. In a torque converter comprising a stator arranged via a one-way clutch that does not allow rotation, at least one of the two impellers has a rotating shaft on a point setting curve on the shell side and a space on the core side. Has a curved surface formed by assembling line elements of a straight line connecting two points set to each of the point setting straight lines drawn in parallel to the point setting straight line. Dotted from outer edge A line element connecting the points arranged along the curve and the points arranged on the point setting line toward the shell side, and the line element of the blade on the inner peripheral side from the point setting line is the inner peripheral end side of the blade. And a line element connecting the points arranged along the point setting curve and one point near the core on the point setting straight line, and the area of a circle having a diameter equal to the outer diameter of the impeller. The core is formed such that the ratio of the area of the flow path is in the range of 0.25 to 0.31.

According to a third aspect of the present invention, there is provided a pump impeller which is connected to an input shaft and defines a flow path through a blade between a shell fixed to a casing and a core, and a pump impeller opposed to the pump impeller. The turbine impeller is connected to the output shaft and defines a flow path between the shell and the core via the blade, and only in one direction between the inlet of the pump impeller and the outlet of the turbine impeller. In a torque converter comprising a stator arranged via a one-way clutch that does not allow rotation, at least one of the two impellers has a blade arranged along a shell-side point setting curve, A curved surface formed by collecting line elements of straight lines connecting the straight line drawn parallel to the rotation axis on the space on the core side and the straight line passing through the flow path tip of the blade on the outer peripheral side from the straight line Holding and feather A passage ratio of the area of the impeller to the area of a circle the outer diameter and the diameter of the forming core so as to range from 0.25 to 0.31.

According to a fourth aspect of the present invention, in the first and second aspects, points along the shell-side point setting curve of each line element and points arranged on the point setting straight line are arranged at equal intervals.

According to a fifth aspect of the present invention, in the first and second aspects, points along the point setting curve on the shell side of each line element and points arranged on the point setting straight line are arranged at unequal intervals. .

[0015]

According to the first to fourth aspects of the present invention, the straight line connecting the point set curve on the shell side and the point set on each of the point set straight lines drawn parallel to the rotation axis on the space on the core side. The line elements are assembled to form a curved surface of the blade, and the area ratio of the flow path is set to 0.
Since the core is formed in the range of 25 to 0.31, it is possible to suppress a decrease in the transmission efficiency due to the leakage flow in the central portion while maintaining a large flow passage area, to secure a good flow, and to improve the pump efficiency and the turbine efficiency. Is improved, and high transmission efficiency of the torque converter can be secured while maintaining the large transmission torque capacity of the coreless torque converter.
Therefore, by improving the potential of the fluid performance of the torque converter, it is possible to improve the fuel efficiency and the power performance of the vehicle. Further, the present invention can be applied to an engine having a wide displacement (torque).

According to the fifth aspect, the curved portion of the blade can be easily formed without greatly affecting the fluid performance.

[0017]

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

As shown in FIG. 1, 20 is a casing 21
Between the pump core 23 and the shell 22 integral with the
And a pump (pump impeller) that defines a flow path via a casing 21 and is connected to an engine (not shown) via a casing 21.

Reference numeral 25 denotes a turbine (turbine impeller) which is arranged to face the pump 20 and defines a flow path between the shell 26 and the turbine core 27 via a blade 28.
The transmission is connected to an input shaft (not shown) of the transmission via a turbine hub 29.

The stator 30 disposed between the inlet of the pump 20 and the outlet of the turbine 25 has a large number of blades 33 arranged between an inner ring 31 and an outer ring (core ring) 32, and is arranged only in one direction. Rotatable one-way clutch 34
Supported through.

The blades 24 and 28 of the pump 20 and the turbine 25 (hereinafter, the blade 24 of the pump 20 will be described as an example) have a point setting curve K ₁ along the base on the shell 22 side as shown in FIG. A curved surface is formed by assembling line elements of straight lines connecting two points set on each of the point setting lines K ₂ drawn in parallel with the rotation axis M on the space on the 23 side.

The point setting line K ₂ is a point setting line L ₂ for setting the blade shape of the coreless torque converter.
And is set substantially at the center between the outer diameter end of the pump 20 (the outer peripheral end of the blade 24) and the inner diameter end of the stator 30.

The point setting line elements on the outer peripheral side of the blade 24 than the straight line K ₂ is the point a ₁ arranged at equal intervals along the point setting curve K ₁ from the outer peripheral edge side of the blade 24, b _1, c ₁ ... And points a ₂ , b ₂ , c ₂ ... Arranged at regular intervals on the point setting line K ₂ toward the shell 22 side.

The point setting line element on the inner circumferential side of the blade 24 than the straight line K ₂ is, p ₁ that are arranged at equal intervals along the set curve K ₁ point towards the inner peripheral edge side of the blade 24, q ₁ , R ₁ ... And points p ₂ , q ₂ , r ₂ ... Arranged at equal intervals on the point setting line K _{2 in the} direction opposite to the shell 22 side.

The point a ₂ is at the intersection of the point setting straight line K ₂ and the straight line passing through the front end of the flow path of the blade 24 on the outer peripheral side of the straight line K ₂ , and the point p ₂ is at the intersection of the point setting straight line K ₂ It is set at the intersection of the straight line passing through the flow channel end portion of the inner peripheral side of the blade 24 than the straight line K _2.

The cores 23 and 27 of the pump 20 and the turbine 25 are formed in a cross-sectional shape having a predetermined curvature along the flow of the pump flow path and the turbine flow path, and maintain a large pump flow path and a turbine flow path. As described above, in this case, the area of the pump flow path and the area of the turbine flow path are in the range of 0.25 to 0.31 with respect to the area of a circle having the outer diameters (both are the same diameter) of the pump 20 and the turbine 25. It is formed to have an area ratio.

The pump core 23 is located near the intersection of the point setting line K ₂ and a straight line passing through the flow path tip of the blade 24 on the inner peripheral side of the straight line K _2. from the inlet end) vicinity, flow channel end portion of the outer peripheral side of the blade 24 in the cross-sectional shape of predetermined curvature to (outlet end of the pump 20), a turbine core 27, the point set straight K ₂ and the straight line K ₂
In the vicinity of the intersection with the straight line passing through the flow path tip of the blade 28 on the more inner peripheral side, from the vicinity of the flow path distal end (outlet end of the turbine 25) of the blade 28, the outer peripheral side of the cross-sectional shape of a predetermined curvature is formed. The blade 28 is provided up to the flow path tip (the inlet end of the turbine 25).

With such a configuration, the fluid sent from the stator 30 flows from the inlet of the pump 20 to the outlet of the pump 20, from the outlet of the pump 20 to the inlet of the turbine 25, and from the inlet of the turbine 25 to the outlet of the turbine 25. And the leakage flow (FIG. 11) in the central portion, which has occurred in the conventional coreless torque converter,
And good flow is maintained around the cores 23, 27.

The blades 24 and 28 of the pump 20 and the turbine 25 are point-set curves K ₁ along the bases on the shells 22 and 26 side and points drawn parallel to the rotation axis M on the space on the cores 23 and 27 side. ₂ set for each of the setting straight lines K 2
The straight line elements connecting the two points are assembled to form a curved surface, so that high blade strength, blade inlet angle, blade outlet angle, and high degree of design freedom in torque converter performance can be obtained. This ensures a better flow of the fluid.

[0030] In this case, to set the curved surface determined separately in the outer peripheral side and inner peripheral side of the point the line element settings straight K _2, the blade inlet angle can be easily set to the blade outlet angle separately.

The areas of the pump flow path and the turbine flow path are set so as to have an area ratio in the range of 0.25 to 0.31 with respect to the area of a circle whose diameter is the outer diameter of the pump 20 and the turbine 25. Since the cores 23 and 27 are formed, a large transmission torque capacity due to a large flow path area is maintained.

As described above, while maintaining a large channel area,
By forming the cores 23 and 27 for restricting the leakage flow in the central portion, the loss due to the leakage flow is suppressed without impairing the transmission torque capacity. In addition, the cores 23 and 27 and the curved blades 24 and 28 can ensure a good flow and improve pump efficiency and turbine efficiency.

Therefore, high transmission efficiency of the torque converter can be secured while maintaining the large transmission torque capacity of the coreless torque converter.

FIG. 3 is an experimental result showing the effect of the present invention. As can be seen from the figure, the present torque converter has a high speed ratio (e.g., 0.6 to 0.3) that is important for power performance during intermediate acceleration, compared to a conventional coreless torque converter.
8) The transmission efficiency can be improved without significantly reducing the torque capacity on the side.

FIG. 4 shows experimental results of fluid performance in each of the conventional coreless torque converter, a general cored torque converter, and the present torque converter. In this case, since the stall torque ratio was almost constant at 2, only the relationship between the torque capacity and the transmission efficiency (speed ratio 0.6) is shown. Since a general core torque converter cannot efficiently flow through the core, if the flow path area is simply increased,
The transmission efficiency is greatly reduced, and the fluid performance potential is not improved. Further, in the conventional coreless torque converter, as described above, the torque capacity is large, but the transmission efficiency is low. On the other hand, the present torque converter can improve the transmission efficiency without significantly reducing the torque capacity, and can sufficiently improve the potential of the fluid performance with the area ratio of 0.25 to 0.31. .

As a result, the applicable range of the engine is expanded, and the fuel efficiency of the vehicle can be improved.

FIG. 5 shows a second embodiment. This (describing the vane 24 of the pump 20 as an example), a linear element of the blade 24 on the inner circumferential side than the set point is drawn parallel to the axis of rotation M in the space of the core 23 side straight K _2, the blade 24 A straight line connecting points p ₁ , q ₁ , r _1, ... Arranged at regular intervals along the point setting curve K ₁ toward the inner peripheral end side, and a point j near the core 23 on the point setting line K _2. Is a line element, and these line elements are assembled to form the curved surface of the blade 24 on the inner peripheral side.

In this case, a good flow is still obtained by the shape of the blades, but the core 2 of the blades 24 and 28 on the inner peripheral side of the point setting line K _{2 is different} from the first embodiment.
The bends near 3,27 can be somewhat increased.

FIG. 6 shows a third embodiment. This is explained by taking the blades 24 of the pump 20 as an example.
Points are arranged at equal intervals along the side points set curve K ₁ a _1,
.., b ₁ , c ₁ , d ₁ , e ₁ , f _1, ..., a straight line drawn in the space on the core 23 side in parallel with the rotation axis M and a straight line passing through the flow path tip of the blade 24 on the outer peripheral side of the straight line. A straight line connecting the intersection point z with the line element is defined as a line element, and these line elements are assembled to form a curved surface from the outer peripheral side to the inner peripheral side of the blade 24.

In this case, the cores 23, ₂ of the blades 24, 28 on the outer side of the point setting line K2 with respect to the first embodiment.
The bend near 7 becomes large.

In each embodiment, the shell 2
A point setting points are drawn parallel to the axis of rotation M linearly K ₂ in the space of 2 side points set point or core 23 side of the curve K ₁ of the equally spaced, but for example, as in FIG. 7 unequal They may be arranged at intervals. In some parts, even if the points for determining the line elements are arranged at unequal intervals, the flow is not so greatly affected, and the formation of a curved surface is facilitated.

The curved surface shape of the blade in each embodiment may be applied to at least one of the pump 20 and the turbine 25.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a first embodiment.

FIG. 2 is an explanatory diagram of a method for defining a line element of a blade curved surface shape.

FIG. 3 is a characteristic diagram showing torque converter performance.

FIG. 4 is a characteristic diagram showing a potential of fluid performance.

FIG. 5 is an explanatory diagram of a line element definition method according to a second embodiment.

FIG. 6 is an explanatory diagram of a line element definition method according to a third embodiment.

FIG. 7 is an explanatory diagram of a line element definition method according to a fourth embodiment.

FIG. 8 is a partial cross-sectional view of a conventional example.

FIG. 9 is a partial front view of the turbine.

FIG. 10 is an explanatory diagram of the line element definition method.

FIG. 11 is an explanatory diagram showing a state of the flow.

[Explanation of symbols]

 Reference Signs List 20 pump (pump impeller) 21 casing 22 shell 23 pump core 24 blade 25 turbine (turbine impeller) 26 shell 27 turbine core 28 blade 30 stator 31 inner ring 32 outer ring 33 blade 34 one-way clutch

Claims (5)

[Claims] 1. A pump impeller connected to an input shaft and defining a flow path through a blade between a shell fixed to a casing and a core, and an output shaft arranged to face the pump impeller. And a turbine impeller that defines a flow path through a blade between the shell and the core, and allows rotation in only one direction between an inlet of the pump impeller and an outlet of the turbine impeller. A stator arranged via a one-way clutch, wherein the blade of at least one of the two impellers is:
It has a curved surface composed of a set of straight-line elements connecting two points set on a point-setting curve on the shell side and a point-setting line drawn parallel to the rotation axis on the space on the core side. The line element of the blade on the outer peripheral side from the point setting straight line is a line element connecting a point arranged along the point setting curve from the outer peripheral end side of the blade and a point arranged on the point setting straight line toward the shell side. , The line elements of the blade on the inner peripheral side of the point setting straight line are arranged along the point setting curve toward the inner peripheral end side of the blade and the points arranged on the point setting straight line in the opposite direction to the shell side. And a core is formed so that the ratio of the area of the flow path of the impeller to the area of a circle whose diameter is the outer diameter of the impeller is in the range of 0.25 to 0.31. A torque converter characterized by: 2. A pump impeller connected to an input shaft and defining a flow path via a blade between a shell fixed to a casing and a core, and an output shaft disposed to face the pump impeller. And a turbine impeller that defines a flow path through a blade between the shell and the core, and allows rotation in only one direction between an inlet of the pump impeller and an outlet of the turbine impeller. A stator arranged via a one-way clutch, wherein the blade of at least one of the two impellers is:
It has a curved surface composed of a set of straight-line elements connecting two points set on a point-setting curve on the shell side and a point-setting line drawn parallel to the rotation axis on the space on the core side. The line element of the blade on the outer peripheral side from the point setting straight line is a line element connecting a point arranged along the point setting curve from the outer peripheral end side of the blade and a point arranged on the point setting straight line toward the shell side. A line element of the blade on the inner peripheral side of the point setting line is a line element connecting a point arranged along the point setting curve toward the inner peripheral end side of the blade and one point near the core on the point setting line. The core is formed such that the ratio of the area of the flow path of the impeller to the area of a circle having the outer diameter of the impeller as a diameter is in the range of 0.25 to 0.31. Torque converter. 3. A pump impeller connected to an input shaft and defining a flow path between a shell fixed to a casing and a core via a blade, and an output shaft disposed opposite to the pump impeller and facing the pump impeller. And a turbine impeller that defines a flow path through a blade between the shell and the core, and allows rotation in only one direction between an inlet of the pump impeller and an outlet of the turbine impeller. A stator arranged via a one-way clutch, wherein the blade of at least one of the two impellers is:
The points arranged along the point setting curve on the shell side, and the intersection of a straight line drawn in parallel with the rotation axis on the space on the core side and a straight line passing through the flow path tip of the blade on the outer peripheral side from the straight line Each of them has a curved surface formed by assembling linear elements connected to each other, and the ratio of the area of the flow path of the impeller to the area of a circle whose diameter is the outer diameter of the impeller is 0.25 to 0. 31. A torque converter, wherein a core is formed so as to fall within a range of 31. 4. The torque converter according to claim 1, wherein points along a point setting curve on a shell side of each line element and points arranged on a point setting straight line are respectively arranged at equal intervals. 5. The torque converter according to claim 1, wherein points along the point setting curve on the shell side of each line element and points arranged on the point setting straight line are arranged at unequal intervals.