JPH0821509A - Torque converter - Google Patents

Abstract

PURPOSE:To improve transmission efficiency by reducing the peeling off of a fluid to the utmost at the time of flowing into a pump impeller from a stator. CONSTITUTION:In the case of a torque converter which is equipped with the three elements of a pump impeller 2, a turbine runner 3 and a stator 4 and is formed so that fluid flow passages to be formed by the respective elements may become uniform flow passage sections, a flow passage contraction portion 11 whose flow passage section becomes less than the maximum flow passage section of the stator 4 is formed at the inlet portion of the pump impeller 2, and the peeling-off of the fluid is restrained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a torque converter that transmits power by using a fluid.

[0002]

2. Description of the Related Art Conventionally, in order to transmit a torque generated by a vehicle engine to an automatic transmission and a propeller shaft, a torque converter as disclosed in, for example, Japanese Patent Laid-Open No. 4-92145 is provided in a drive system. . In this case, in a torque converter that is formed flat due to the demand for miniaturization, if a throttle is provided in the middle part of the pump impeller or turbine runner in order to weaken the deceleration of the average flow velocity, the flow velocity distribution will fluctuate, resulting in fluid loss. Occurs, suppress the change in the curvature of the core from the inlet to the outlet of the pump impeller and turbine runner so as to minimize this,
The flow velocity distribution is made uniform.

[0003]

However, as shown in FIG. 4, when the fluid is circulated from the stator 4 to the pump impeller 2 while rotating the turbine runner 3 by the rotation of the pump impeller 2, there is also a diagram. So that the stator 4
4b and core 2 at the outlet of the pump and the inlet of the pump impeller 2
Since b partially overlaps and the inner surface of the core is not smoothly joined, a part of the fluid flowing along the core 2b causes separation, and in particular, the pump impeller 2 tends to increase separation due to the reduction blade row. is there.

If there is a loss due to fluid separation in a part of the pump impeller 2 as described above, the transmission efficiency of the torque converter is reduced accordingly.

An object of the present invention is to reduce the separation of fluid when flowing into the pump impeller from the stator as much as possible and to improve the transmission efficiency.

[0006]

Therefore, a first aspect of the present invention is provided with three elements of a pump impeller, a turbine runner, and a stator, and fluid passages formed by the respective elements have equal passage cross sections. In the torque converter described above, a flow passage reducing portion whose flow passage cross section is equal to or smaller than the maximum flow passage cross section of the stator is formed at the inlet of the pump impeller.

In a second aspect based on the first aspect, the flow path reducing portion is formed by a throttle portion in which a part of the core of the pump impeller is bulged.

According to a third aspect of the present invention, in the second aspect of the invention, the throttle portion is changed at a constant rate from the flow passage cross section toward the end point and / or the rate of change of the flow passage cross section at the beginning and end of the throttle. Is formed so as to approach zero.

According to a fourth aspect of the present invention, in the first to third aspects of the present invention, a flow passage reducing portion is formed at the inlet of the turbine runner so that the flow passage cross section is smaller than the outlet flow passage cross section of the pump impeller.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, a flow passage reducing portion is formed at the outlet of the pump impeller.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, the flow passage reducing portion is also formed at the outlet of the turbine runner.

[0012]

In the first aspect of the invention, the fluid flowing from the stator into the pump impeller is throttled by the flow passage reducing portion near the inlet,
Even if there is a step in the connection of the flow paths along the core, fluid separation is suppressed or vortex flow due to fluid separation is attenuated. This reduces the loss of fluid flowing through the pump impeller and improves the transmission efficiency and torque capacity of the torque converter.

In the second aspect of the present invention, the fluid separation tends to occur along the surface of the core, but since the throttle portion is provided in a part of the core, the fluid separation can be reliably suppressed.

In the third aspect of the invention, since the diaphragm is constant and the rate of change at the beginning and the end of the diaphragm is extremely small,
The flow of the fluid in the throttle portion becomes smooth and the fluid loss is small.

In the fourth aspect of the invention, the fluid is likely to be separated at the outlet of the pump impeller due to the centrifugal force or the sharp bend of the flow passage. However, by narrowing the inlet of the turbine runner, the fluid is separated at the turbine runner. Reduce and reduce fluid loss.

In the fifth aspect of the present invention, the separation of fluid at the outlet of the pump impeller is suppressed and the separation fluid flowing into the turbine runner is reduced.

According to the sixth aspect of the invention, the pump impeller and the turbine runner have the same shape, and the core and blades can be shared.
It can also reduce costs.

[0018]

FIG. 1 shows the first embodiment of the present invention.
The pump impeller 2 attached to the converter cover 1 connected to the engine crankshaft is composed of an outer pump shell 2a, an inner core 2b, and pump vanes 2c. The turbine runner 3 arranged to face the pump shell 2a includes an outer turbine shell 3a,
It is composed of an inner core 3b and turbine blades 3c, is coupled to a hub 5 coaxial with the pump impeller 2, and rotates integrally with a transmission input shaft (not shown). The stator 4 sandwiched between the pump impeller 2 and the turbine runner 3 includes a shell side ring 4a, a core side ring 4b,
A stator blade 4c and a housing (not shown) are supported by a one-way clutch 6 coaxially with the input shaft. In order to prevent the flow from the outlet of the turbine runner 3 passing through the outside of the core side ring 4b of the stator 4 into the pump impeller 2, the core side ring 4b and the cores of the pump impeller 2 and the turbine runner 3 are blocked. Part of 2b, 3b is configured to overlap each other.

The flow passages are formed so that the flow passage cross-sectional areas of the fluid circulating through the pump impeller 2, the turbine runner 3, and the stator 4 are, in principle, equal flow passage cross-sections. This equal flow path cross section is formed when each line segment formed by an intersection of both line segments orthogonal to the flow path and a point in the middle thereof is rotated about the rotation center of the torque converter. The intermediate points are set so that the surface areas of the two truncated cones are equal to each other, and a circle formed by connecting these intermediate points over the entire circumference of the flow path is defined as a design path m, and is orthogonal to the design path m. Each flow passage area SA of the cross section is made equal in all of the pump impeller 2, the turbine runner 3, and the stator 4.

In the present invention, the pump impeller 2 into which the fluid from the stator 4 flows in in such an equal flow path cross section.
Is formed at the inlet portion of the flow path reducing portion 11 having a flow path cross section smaller than the maximum flow path cross section of the stator 4.

In this embodiment, the flow passage reducing portion 11 is formed as a throttle portion 11a in which a part of the core 2b of the pump impeller 2 is bulged toward the flow passage side, and the throttle portion 11a is substantially constant over a predetermined range. The flow passage cross section is narrowed at a ratio of, and the flow passage cross sectional area is smoothly changed so that the rate of change of the flow passage cross section becomes close to zero at the start point and the end point.

With this configuration, when the pump impeller 2 rotates, the fluid to which the kinetic energy has been applied flows to the turbine runner 3, causing the turbine runner 3 to rotate in the same direction, and from the turbine runner 3 to the stator 4. A circulating flow is formed in which the flow direction is changed to the rotation direction of the pump impeller 2 by flowing in, and the flow is again flowed into the pump impeller 2.

The fluid flowing from the stator 4 into the pump impeller 2 is a step formed at an overlapping portion of the core side ring 4b and the core 2b, and a sharply bent portion due to a rapid change in the curvature of the core 2b, particularly the core. The separation tends to occur in a part of the fluid flow along the inner peripheral surface. But,
A flow path reducing portion 11 is formed at the inlet of the pump impeller 2 to narrow the flow path, so that separation of the fluid flowing along the inner peripheral surface of the core is suppressed, vortexes due to the separation of the fluid are prevented, and the pump impeller is prevented. The fluid loss in 2 can be reduced as much as possible.

Since the throttle portion 11a does not abruptly change the flow passage cross section of the pump impeller 2, the core 2b
The flow along the can be stabilized.

Although not shown, the pump impeller 2
In terms of the performance of the core side ring 4 at the outlet of the stator 4, when it is not desired to reduce the flow path contracting portion 11 at the inlet.
It is also possible to form a narrowed portion also in b and suppress peeling by cooperation of these.

In this way, separation of the fluid flowing from the stator 4 to the pump impeller 2 is prevented, the flow is stabilized and the fluid loss is reduced, so that the transmission efficiency and torque capacity of the torque converter can be improved.

Next, the embodiment of FIG. 2 will be described. In addition to the first flow path reducing section 11 at the inlet of the pump impeller 2, the flow path cross-section at the inlet of the turbine runner 3 has a pump cross section. By forming the second flow path reducing portion 13 which is smaller than the cross section of the outlet flow path of the impeller 2, separation of the fluid flowing into the turbine runner 3 is suppressed and vortices are attenuated.

The passage of the flow passage from the outlet of the pump impeller 2 to the inlet of the turbine runner 3 tends to be non-smooth, and at the outlet of the pump impeller 2, due to the influence of centrifugal force and the change in curvature of the core 2b. And turbine runner 3
Separation easily occurs in the flow of the fluid flowing into the. However, by forming the second flow path reducing portion 13 at the inlet of the turbine runner 3 as the throttle portion 13a in which the inner surface of the core 3b is bulged, such fluid separation and vortex generation are minimized. Can be suppressed.

The narrowed portion 13a is the first narrowed portion 11a.
Similarly to the above, the flow path is formed so as to be smoothly narrowed at a constant ratio.

Further, in the embodiment of FIG. 3, the flow path reducing portion 15 is also formed at the outlet of the pump impeller 2 so as to suppress fluid separation at the outlet of the pump impeller 2.

Therefore, in this embodiment, the first flow path reducing section 11 is provided at the inlet of the pump impeller 2, and the second flow path reducing section 13 is provided at the inlet of the turbine runner 3, and further the third flow path reducing section 13 is provided.
As the flow path reducing section 15 of the pump impeller 2, a throttle section 15a in which a part of the inner surface of the core 2b of the outlet section of the pump impeller 2 is bulged is provided to suppress separation of fluid generated at the outlet section of the pump impeller
The generation of swirl in the turbine runner 3 is prevented.

In this case, the fourth flow path reducing portion 17 can also be formed at the outlet of the turbine runner 3 as a throttle portion 17a in which the core 3b is bulged. Since the turbine runner 3 is a speed-increasing blade, separation does not occur at the outlet, but if this is done, the pump impeller 2 and turbine runner 3
Have the same shape, the cores 2b and 3b and the blades 2c and 3c can be shared, and the manufacturing cost of the torque converter can be reduced.

[0033]

As described above, according to the first invention, the pump impeller, the turbine runner, and the stator are provided, and the flow passages of the fluid formed by the respective elements have equal flow passage cross sections. In the formed torque converter, since the flow passage cross-section where the flow passage cross section is equal to or smaller than the maximum flow passage cross section of the stator is formed at the inlet of the pump impeller,
The fluid flowing from the stator into the pump impeller is throttled by the flow passage reducing portion near the inlet, and even if there is a step in the connection of the flow passages along the core, separation is suppressed, or vortex flow due to fluid separation is attenuated, and The loss of fluid flowing to the pump impeller is reduced, and the transmission efficiency and torque capacity of the torque converter are improved.

According to the second aspect of the invention, since the flow path contracting portion is formed as a constricted portion in which a part of the core of the pump impeller is bulged out, the flow of the fluid which is about to be generated along the core surface of the pump impeller. Peeling can be reliably suppressed.

According to the third aspect of the invention, the throttle portion changes the cross section of the flow path from the starting point to the ending point at a constant rate.
Since the change rate of the cross section of the flow passage at the beginning and the end of the restriction is close to zero, the restriction is constant, and the change rate at the start and the end of the restriction is extremely small. It is smooth and the fluid loss can be reduced.

According to the fourth aspect of the invention, since the flow passage cross-section is formed at the inlet of the turbine runner so that the flow passage cross section is smaller than the outlet flow passage cross section of the pump impeller. It is possible to reduce the separation of the generated fluid and the fluid loss.

According to the fifth aspect of the invention, since the flow path reducing portion is formed at the outlet portion of the pump impeller, the fluid separation at the outlet portion of the pump impeller is suppressed and the separation fluid flowing into the turbine runner is reduced. be able to.

According to the sixth aspect of the present invention, since the flow path reducing portion is formed at the inlet and outlet of the pump impeller and the inlet and outlet of the turbine runner, the separation of fluid is suppressed and the loss is reduced, while the pump is reduced. Since the impeller and turbine runner have the same shape, the core and blades can be shared, and cost reduction can be expected.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the same.

FIG. 3 is a sectional view showing a third embodiment of the same.

FIG. 4 is a sectional view of a conventional example.

[Explanation of symbols]

 1 Converter Cover 2 Pump Impeller 2a Pump Shell 2b Pump Core 2c Pump Blade 3 Turbine Runner 3a Turbine Shell 3b Turbine Core 3c Turbine Blade 4 Stator 4a Shell Side Ring 4b Core Side Ring 4c Stator Blade 11 Flow Reduction Section 11a Throttling Section 13 Flow Path Reduction unit 13a Throttle unit 15 Flow path reduction unit 17 Flow path reduction unit

Claims (6)

[Claims] 1. A torque converter including three elements, a pump impeller, a turbine runner, and a stator, wherein a fluid passage formed by each element has an equal passage cross section, and an inlet portion of the pump impeller. A torque converter characterized in that a flow passage contraction portion having a flow passage cross section equal to or smaller than the maximum flow passage cross section of the stator is formed in the torque converter. 2. The torque converter according to claim 1, wherein the flow path reducing portion is formed as a throttle portion in which a part of the core of the pump impeller is bulged. 3. The throttle portion is formed so as to change the flow passage cross section from the starting point to the end point at a constant rate and / or so that the change rate of the flow passage cross section at the beginning and end of the throttle approaches zero. The torque converter according to claim 2, which is characterized in that 4. A flow path reducing portion having a flow passage cross section smaller than an outlet flow passage cross section of the pump impeller is formed at an inlet portion of the turbine runner. The described torque converter. 5. The torque converter according to claim 4, wherein a flow passage reducing portion is formed at an outlet portion of the pump impeller. 6. The torque converter according to claim 5, wherein a flow passage reducing portion is also formed at an outlet portion of the turbine runner.