JP3298314B2 - Torque converter - Google Patents

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 for transmitting power using a fluid.

[0002]

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

[0003]

However, as shown in FIG. 4, there is also a case where fluid circulates from the stator 4 to the pump impeller 2 while rotating the turbine runner 3 by rotation of the pump impeller 2. As the stator 4
Ring 4b and core 2 at outlet of pump and inlet of pump impeller 2
b partially overlaps and the inner surface of the core is not smoothly joined, so that a part of the fluid flowing along the core 2b is separated, and in particular, the separation of the pump impeller 2 tends to increase due to the deceleration cascade. is there.

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

[0005] It is an object of the present invention to minimize the separation of fluid when flowing into a pump impeller from a stator and improve transmission efficiency.

[0006]

Accordingly, a first aspect of the present invention provides a pump impeller, a turbine runner, and a stator, which are formed so that a fluid flow path formed by each element has an equal flow path cross section. In the torque converter thus manufactured, a flow passage reducing portion having a flow passage cross section smaller than or equal to the maximum flow passage cross section of the stator was formed at the inlet of the pump impeller.

According to a second aspect of the present invention, in the first aspect, the flow path reducing portion is formed by a constricted portion in which a part of a core of the pump impeller is expanded.

According to a third aspect of the present invention, in the second aspect, the throttle section changes the flow path cross section at a constant rate from the starting point to the end point, and / or the rate of change of the flow path cross section at the start and end of the throttle. Are formed to approach zero.

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

In a fifth aspect based on the fourth aspect, a flow passage reducing portion is formed at an outlet of the pump impeller.

In a sixth aspect based on the fifth aspect, a flow passage reducing portion is also formed at the outlet of the turbine runner.

[0012]

According to the first aspect of the invention, the fluid flowing from the stator into the pump impeller is restricted by the flow path reducing portion near the inlet,
Even if there is a step in the connection of the flow paths along the core, the separation of the fluid is suppressed, or the vortex caused by the separation of the fluid is attenuated. Thereby, the loss of the fluid flowing through the pump impeller is reduced, and the transmission efficiency and the torque capacity of the torque converter are improved.

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

In the third aspect of the present invention, the stop becomes constant and the rate of change between the start and end of the stop becomes extremely small.
Fluid flow in the throttle portion is smooth and fluid loss is small.

In the fourth aspect of the present invention, the separation of the fluid is likely to occur at the outlet of the pump impeller due to the centrifugal force or the sharp bend of the flow path. However, the separation of the fluid at the turbine runner is reduced by narrowing the inlet of the turbine runner. Reduce fluid losses.

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

In the sixth aspect, the pump impeller and the turbine runner have the same shape, and the core and the blade can be shared.
Costs can also be reduced.

[0018]

FIG. 1 shows a first embodiment of the present invention.
The pump impeller 2 attached to the converter cover 1 connected to the engine crankshaft includes an outer pump shell 2a, an inner core 2b, and a pump blade 2c. The turbine runner 3 disposed facing the pump shell 2a includes an outer turbine shell 3a,
It is composed of an inner core 3b and a turbine blade 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,
It is constituted by a stator blade 4c and supported by a housing (not shown) coaxially with the input shaft via a one-way clutch 6. In order to prevent a flow from the outlet of the turbine runner 3 through the outside of the core-side ring 4b of the stator 4 to flow into the pump impeller 2, the core-side ring 4b and each core of the pump impeller 2 and the turbine runner 3 Parts 2b and 3b are configured to overlap each other.

The flow path is formed such that the flow path cross-sectional area of the fluid circulating through the pump impeller 2, the turbine runner 3, and the stator 4 is, in principle, an equal flow path cross section all around. This equal flow path cross section is formed when each line segment formed by both intersections of a line segment orthogonal to the flow path and a point in the middle thereof is rotated around 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 when 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. The flow passage area SA of the cross section is the same in all of the pump impeller 2, the turbine runner 3, and the stator 4.

According to the present invention, the pump impeller 2 into which the fluid from the stator 4 flows has such an equal flow path cross section.
At the inlet of the stator 4, the flow passage reducing portion 11 having a smaller flow passage cross section than the maximum flow passage cross section of the stator 4 is formed.

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

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, rotates the turbine runner 3 in the same direction, and further moves from the turbine runner 3 to the stator 4. The gas flows in and changes the direction of the flow to the rotation direction of the pump impeller 2 to form a circulating flow in which the gas flows into the pump impeller 2 again.

The fluid flowing from the stator 4 into the pump impeller 2 is caused by a step formed at a portion where the core side ring 4b and the core 2b overlap with each other, and a sharp bend caused by a sharp change in the curvature of the core 2b. An attempt is made to cause separation in a part of the fluid flow along the inner peripheral surface. But,
At the inlet of the pump impeller 2, a flow channel reducing portion 11 is formed, and the flow channel is narrowed, so that the separation of the fluid flowing along the inner peripheral surface of the core is suppressed, and the generation of a vortex due to the separation of the fluid is prevented. 2 can be reduced as much as possible.

Since the throttle 11a does not rapidly change the cross section of the flow path of the pump impeller 2, the core 2b
The flow along is stabilized.

Although not shown, the pump impeller 2
Due to the performance of the above, when it is not desired to narrow down the flow passage reducing portion 11 at the inlet portion, the core side ring 4
A narrowed portion may also be formed in b, and peeling may be suppressed by the cooperation of these.

As described above, the separation of the fluid flowing from the stator 4 into the pump impeller 2 is prevented, the flow is stabilized, and the fluid loss is reduced, whereby the transmission efficiency and torque capacity of the torque converter can be improved.

Next, the embodiment shown in FIG. 2 will be described. This is because, in addition to the first flow passage reducing portion 11 at the inlet of the pump impeller 2, the cross section of the flow passage is also provided at the inlet of the turbine runner 3. By forming the second flow path reducing portion 13 smaller than the outlet flow path cross section of the impeller 2, the separation of the fluid flowing into the turbine runner 3 is suppressed, and the vortex is attenuated.

The connection of the flow path 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 is caused by the influence of centrifugal force and the change in the curvature of the core 2b. And the turbine runner 3
Separation is likely to occur in the flow of the fluid flowing into the device. However, by forming the second flow passage reducing portion 13 at the inlet of the turbine runner 3 as a constricted portion 13a in which the inner surface of the core 3b is expanded, such separation of fluid and generation of a vortex are minimized. Can be suppressed.

It should be noted that the throttle section 13a is connected to the first throttle section 11a.
In the same manner as described above, it is formed so as to narrow the flow path smoothly at a fixed ratio.

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

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

In this case, the fourth flow passage 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 expanded. Since the turbine runner 3 is a speed increasing blade, there is no separation at the outlet, but in this case, the pump impeller 2 and the turbine runner 3
Have the same shape, and the cores 2b, 3b and the blades 2c, 3c can be shared, which can contribute to a reduction in the manufacturing cost of the torque converter.

[0033]

As described above, according to the first aspect, a pump impeller, a turbine runner, and a stator are provided, and a fluid flow path formed by each element has an equal flow path cross section. In the formed torque converter, since the flow path cross-section was formed at the inlet of the pump impeller so that the flow path cross-section was not more than the maximum flow path cross-section of the stator,
Fluid flowing from the stator into the pump impeller is throttled by the flow path reducing portion near the inlet, and separation is suppressed even if there is a step in the connection of the flow path along the core, or eddy current due to fluid separation is attenuated. The loss of fluid flowing through the pump impeller is reduced, and the transmission efficiency and torque capacity of the torque converter are improved.

[0034] According to the second aspect of the present invention, since the flow passage reducing portion is formed as a constricted portion in which a part of the core of the pump impeller is swollen, the flow of the fluid which is likely to be generated along the surface of the core of the pump impeller. Peeling can be reliably suppressed.

According to the third aspect, the throttle section changes the cross section of the flow path from the starting point to the end point at a constant rate,
And, since the rate of change of the flow path cross section at the start and end of the throttle is formed close to zero, the throttle becomes constant, and the rate of change at the start and end of the throttle becomes extremely small, so that the flow of fluid in the throttle portion And fluid loss can be reduced.

According to the fourth aspect of the present invention, since the flow passage cross-section is formed at the inlet of the turbine runner so as to have a smaller flow cross-section than the outlet flow cross-section of the pump impeller, the gas flows from the pump impeller into the turbine runner. Fluid separation is reduced, and fluid loss is reduced.

According to the fifth aspect of the present invention, since the flow passage reducing portion is formed at the outlet of the pump impeller, the separation of the fluid at the outlet of the pump impeller is suppressed, and the separating 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 portions are formed at the inlet and the outlet of the pump impeller and at the inlet and the outlet of the turbine runner, the separation of the fluid is suppressed and the loss is reduced. The impeller and the turbine runner have the same shape, so that the core and blades can be shared and cost reduction can be expected.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view showing a second embodiment.

FIG. 3 is a sectional view showing a third embodiment.

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

[Explanation of symbols]

 DESCRIPTION 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 path reducing part 11a Throttle part 13 Flow path Reduction section 13a Narrowing section 15 Channel reduction section 17 Channel reduction section

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-27502 (JP, A) JP-A-5-71610 (JP, A) JP-A-4-92145 (JP, A) 135051 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 41/26

Claims (6)

(57) [Claims] 1. A torque converter including a pump impeller, a turbine runner, and a stator, wherein a fluid flow path formed by each element has an equal flow path cross section. A torque converter, wherein a flow passage reducing portion whose flow passage cross section is smaller than the maximum flow passage cross section of the stator is formed. 2. The torque converter according to claim 1, wherein the flow passage reducing portion is formed as a throttle portion in which a part of a core of the pump impeller is expanded. 3. The throttle section may be formed such that the cross section of the flow path changes at a constant rate from the starting point to the end point, and / or the rate of change of the flow path cross section at the start and end of the narrowing approaches zero. 3. The torque converter according to claim 2, wherein: 4. The turbine runner according to claim 1, wherein a passage cross-section is formed at an inlet of the turbine runner so that a cross-section of the passage is smaller than a cross-section of an outlet of the pump impeller. The torque converter as described. 5. The torque converter according to claim 4, wherein a flow passage reducing portion is formed at an outlet of the pump impeller. 6. The torque converter according to claim 5, wherein a flow passage reducing portion is also formed at an outlet of the turbine runner.