JP2005249206A - Torque converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque converter having excellent performance by adjusting dimension and position of each of parts, in regard to a torque converter to be located within a limited axial dimension. <P>SOLUTION: An impeller 18 is arranged on a transmission side of a front cover 14 to structure a fluid chamber with the front cover 14, and provided with a plurality of blades 23 inside thereof. A turbine 19 is arranged on an engine side of the impeller 18 inside the fluid chamber, and provided with a plurality of blades on a side opposite to the impeller 18. A stator 20 is arranged between an inner peripheral part of the impeller 18 and an inner peripheral part of the turbine 19 to straighten a flow of the fluid flowing from the turbine 19 to the impeller 8. The impeller 18, the turbine 19 and the stator 20 form a torus 6. The torus 6 is formed to have 0.7 or less of a flat ratio (L/H) as a ratio of an axial dimension L to a radial dimension H. Axial dimension Lt of the turbine 19 is formed shorter than axial dimension Lp of the impeller 18. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a torque converter, and more particularly to a flat type torque converter in which a shaft dimension of a torus is shortened.

  The torque converter is a device that has a torus (impeller, turbine, stator) composed of three types of impellers, and transmits power by a fluid inside the torus. As such a torque converter, there is known a torque converter in which the flatness of the torus is reduced and the torus is crushed in the axial direction. By making the torus ultra flat in this way, the axial dimension of the entire torque converter can be shortened, and the torque converter can be installed in a space limited in the axial direction.

  In the torque converter, a lockup device is provided in a space between the front cover and the torus. The lock-up device is a device for mechanically transmitting the torque of the front cover to the transmission side. The lockup device includes a clutch coupling portion and a damper mechanism. The clutch connecting portion is connected to or released from the front cover by a change in hydraulic pressure in the torque converter. The damper mechanism is composed of a plurality of torsion springs, for example. The torsion spring has a function of absorbing and dampening vibration in the torsional direction in a state where the lockup device is connected.

With the increase in engine torque in recent years, the lock-up device has been made into a multi-plate having a plurality of friction surfaces.
Further, in recent years, a torque converter is known that transmits torque by a fluid only at the time of starting and connects a lock-up device at, for example, 10 km / h or more. In the structure in which the lockup region is increased as described above, it is required to improve the performance of the torsion spring so that the torsional vibration can be sufficiently absorbed and attenuated against the torque fluctuation from the engine.

As described above, the lock-up device needs to have a large axial dimension in order to increase the number of plates and improve the performance of the torsion spring.
An object of the present invention is to shorten the axial dimension of the entire torque converter while maintaining the current performance or improving the performance.

  Another object of the present invention is to obtain excellent performance by adjusting the size and position of each component in a torque converter installed in a limited axial dimension.

  According to a first aspect of the present invention, there is provided a torque converter for transmitting torque from an engine to a transmission side by a fluid, and includes a front cover, an impeller, a turbine, and a stator. The front cover is disposed on the engine side and receives torque from the engine. The impeller is disposed on the transmission side of the front side, forms a fluid chamber together with the front cover, and has a plurality of blades inside. The turbine is disposed on the engine side of the impeller in the fluid chamber, and a plurality of blades are provided on the side facing the impeller, so that torque can be output to the transmission. The stator is disposed between the impeller and the inner peripheral portion of the turbine, and is for rectifying the flow of fluid flowing from the turbine to the impeller. The impeller, turbine, and stator constitute a torus. The torus has a flatness ratio (L / H) that is a ratio of the axial dimension L to the radial dimension H of 0.7 or less. The axial dimension Lt of the turbine is shorter than the axial dimension Lp of the impeller.

In this torque converter, the flatness of the torus (L / H) is 0.7 or less, and the flattening is progressing. Furthermore, since the axial dimension Lt of the turbine is shorter than the axial dimension Lp of the impeller, the axial dimension of the torus is further shortened compared to the conventional one. As a result, the axial dimension of the entire torque converter can be shortened, or in the torque converter arranged within a predetermined axial dimension, for example, the space in which the lockup device is arranged can be enlarged in the axial direction.
Further, in this torque converter, the ratio (Lt / Lp) of the shaft dimension Lt to the shaft dimension Lp is in the range of 0.7 to 0.9.

  The stator further includes an annular carrier, a plurality of blades provided on the outer peripheral surface of the carrier and disposed between the impeller and the turbine, and an annular core fixed to the tips of the plurality of blades. . The plurality of blades have a portion protruding toward the axial transmission side with respect to the core. Therefore, in a flat and asymmetric torque converter (the turbine shaft dimension Lt is smaller than the impeller shaft dimension Lp), the plurality of stator blades have portions protruding toward the axial transmission side with respect to the core. In other words, the core does not have a portion corresponding to the blade on the impeller side. Thus, the fluid flowing from the turbine outlet through the stator to the impeller inlet is not obstructed by the stator core as it flows from the stator outlet toward the impeller inlet. As a result, the fluid motion conversion capability in the stator is not lowered, and high performance is obtained.

  In this torque converter, in Claim 3, the axial transmission side edges of the plurality of blades are located closer to the axial transmission side than the axial transmission side surface of the core.

  In a torque converter according to a second aspect, in the first aspect, the ratio (S2 / S1) of the axial dimension S2 of the core to the axial dimension S1 of the plurality of blades is in the range of 0.6 to 0.9. Therefore, the balance of a plurality of blades and cores can be sufficiently corrected.

According to a third aspect of the present invention, in the first or second aspect, the axial engine side edges of the plurality of blades coincide with the axial engine side surface of the core in the axial direction.
According to a fourth aspect of the present invention, in any one of the first to third aspects, the axial center position of the plurality of blades is located closer to the axial transmission side than the axial position between the impeller outlet and the turbine inlet.

  In this torque converter, since the plurality of blades of the stator are arranged shifted to the impeller side with respect to the axial direction position of the impeller and the turbine, the asymmetric torque converter in which the axial dimension Lt of the turbine is shorter than the axial dimension Lp of the impeller. In this case, interference between the turbine and the stator hardly occurs.

  According to a fifth aspect of the present invention, in the torque converter according to any one of the first to fourth aspects, the axial engine side edges of the plurality of blades are located closer to the axial engine side than the axial position. The axial distance S3 between the axial engine side edges of the plurality of blades and the axial position is 5 mm or less.

  In this torque converter, although the axial engine side edges of a plurality of blades are located on the axial engine side with respect to the axial direction position between the impeller and the turbine, the distance S3 is 5 mm or less, so that the flattened and asymmetrical shape is achieved. In a torque converter, interference between the turbine and the stator hardly occurs.

  In the torque converter according to claim 6, in any one of claims 1 to 5, the impeller includes an impeller shell, an impeller blade fixed to the impeller shell, and an impeller core fixed to the impeller blade. The turbine includes a turbine shell, a turbine blade fixed to the turbine shell, and a turbine core fixed to the turbine blade. The tip of the inner peripheral end of the impeller core is positioned on the axial transmission side from the tip of the outer peripheral end, and the tip of the inner peripheral end of the turbine core is positioned on the axial transmission side of the outer peripheral end.

  In the torque converter according to claim 7, in any one of claims 1 to 5, the turbine includes a turbine shell, a turbine blade fixed to the turbine shell, and a turbine core fixed to the turbine blade. The inner peripheral end of the turbine core protrudes from the turbine blade and is disposed on the outer peripheral side of the stator core.

  According to an eighth aspect of the present invention, in the seventh aspect, the tip of the inner peripheral end of the turbine core is located closer to the axial transmission side than the axial position between the impeller outlet and the turbine inlet.

  In the torque converter according to the present invention, the flatness of the torus (L / H) is 0.7 or less, and the flattening is progressing. Furthermore, since the axial dimension Lt of the turbine is shorter than the axial dimension Lp of the impeller, the axial dimension of the torus is further shortened compared to the conventional one. As a result, in the torque converter disposed within a predetermined axial dimension, for example, a space in which the lockup device is disposed can be increased in the axial direction.

(1) Basic Structure FIG. 1 is a schematic vertical sectional view of a torque converter 1 in which one embodiment of the present invention is adopted. The torque converter 1 is a device for transmitting torque from an engine crankshaft 2 to an input shaft (not shown) of a transmission. An engine (not shown) is arranged on the left side of FIG. 1, and a transmission (not shown) is arranged on the right side of FIG. The OO line shown in FIG. 1 is the rotating shaft of the torque converter 1.

  The torque converter 1 mainly includes a flexible plate 4 and a torque converter body 5. The flexible plate 4 is a member made of a thin disc-like plate material, which transmits torque and absorbs bending vibration input to the torque converter 1 from the crankshaft 2 side.

  The torque converter body 5 includes a torus 6 including three types of impellers (impeller 18, turbine 19, stator 20) and a lockup device 7.

  The front cover 14 is a disk-shaped member and is disposed in the vicinity of the flexible plate 4. A center boss 15 is fixed to the inner periphery of the front cover 14 by welding. The center boss 15 is a cylindrical member extending in the axial direction, and is inserted into the center hole of the crankshaft 2.

  The inner peripheral portion of the flexible plate 4 is fixed to the crankshaft 2 by a plurality of bolts 10. A plurality of nuts 11 are fixed at equal intervals in the circumferential direction on the outer peripheral side of the front cover 14 and the engine side. A bolt 12 screwed into the nut 11 fixes the outer peripheral portion of the flexible plate 4 to the front cover 14. An annular ring gear member 13 is fixed to the outer peripheral portion of the flexible plate 4.

  An outer peripheral cylindrical portion 16 extending toward the axial transmission side is formed on the outer peripheral portion of the front cover 14. The outer peripheral edge of the impeller shell 22 of the impeller 18 is fixed to the tip of the outer peripheral cylindrical portion 16 by welding. As a result, the front cover 14 and the impeller 18 form a fluid chamber filled with hydraulic oil (fluid). The impeller 18 mainly includes an impeller shell 22, a plurality of impeller blades 23 fixed to the inside of the impeller shell 22, and an impeller hub 24 fixed to the inner peripheral portion of the impeller shell 22.

The turbine 19 is disposed to face the impeller 18 in the axial direction in the fluid chamber. The turbine 19 mainly includes a turbine shell 25 and a plurality of turbine blades 26 fixed to the surface of the turbine shell 25 on the impeller side. An inner peripheral portion of the turbine shell 25 is fixed to a flange of the turbine hub 27 by a plurality of rivets 28.
The turbine hub 27 is connected to an input shaft (not shown) so as not to be relatively rotatable.

  The stator 20 is a mechanism for rectifying the flow of hydraulic oil returning from the turbine 19 to the impeller 18. The stator 20 is an integral member manufactured by casting with resin, aluminum alloy or the like. The stator 20 is disposed between the inner periphery of the impeller 18 and the inner periphery of the turbine 19. The stator 20 mainly includes an annular carrier 29, a plurality of stator blades 30 provided on the outer peripheral surface of the carrier 29, and an annular core 31 fixed to the tips of the plurality of stator blades 30. . The carrier 29 is supported by a fixed shaft (not shown) via a one-way clutch 35.

  The one-way clutch 35 is supported by an outer race 33 fixed to the carrier 29 and an inner race 34 fixed to a fixed shaft. A thrust bearing 39 is disposed between the carrier 29 and the impeller hub 24. An annular locking member 36 is arranged on the axial engine side of the outer race 33 of the one-way clutch 32. The locking member 36 prevents the member of the one-way clutch 32 from dropping off in the axial direction. A thrust bearing 40 is disposed between the locking member 36 and the turbine hub 27.

  The torque converter 1 has a significantly reduced axial dimension as compared with the conventional one. Specifically, the flatness ratio (L / H), which is the ratio between the radial dimension H and the axial dimension L of the torus 6, is 0.7 or less. The axial dimension L of the torus 6 is the distance between the most transmission side portion inside the impeller shell 22 and the most engine side portion inside the turbine shell 25 of the turbine 19, and the radial dimension H is the outer peripheral surface of the carrier 29. Is the distance between the innermost surface of the impeller shell 22 or the turbine shell 25 and the radially outermost surface.

  The turbine 19 has a shorter shaft dimension than the impeller 18. That is, in the torus 6, the impeller 18 and the turbine 19 are asymmetric in the axial direction. The ratio (Lt / Lp) of the axial dimension Lt of the turbine 19 to the axial dimension Lp of the impeller 18 is between 0.7 and 0.9. The axial dimension Lt of the turbine 19 is a distance between the axial position C1 between the outlet of the impeller 18 and the inlet of the turbine 19 and the innermost part of the turbine shell 25 between the engine side portion. The axial dimension Lp of the impeller 18 is a distance from the axial position C1 to the most transmission side portion inside the impeller shell 22.

As described above, in the torque converter 1 that has been flattened, the axial dimension of the turbine 19 can be further shortened so as to be asymmetrical, whereby the axial dimension of the entire torque converter 1 can be further shortened.
The blade 30 of the stator 20 will be described in detail.

2. Shape of Blade 30 Each of the plurality of blades 30 has a blade-shaped cross section as shown in FIG. 2, and extends long in the radial direction as shown in FIG. The axial engine side edge 30a and the axial transmission side edge 30b of the blade 30 extend in the radial direction. The axial dimension S1 of the blade 30 is shorter than the axial length of the outer peripheral surface of the carrier 29.

Position of Blade 30 Each blade 30 is disposed in a fluid passage between the carrier 29 and the core 31. Each blade 30 extends from the axial transmission side of the carrier 29.

Relationship Between Blade 30 and Core 31 The core 31 is an annular member, and has an axial engine side surface 31a and an axial transmission side surface 31b. Both surfaces 31a and 31b are annular surfaces having a predetermined width in the radial direction. The radial width of the axial engine side surface 31a is shorter than the radial width of the axial transmission side surface 31b. The axial transmission side portion of the blade 30 protrudes from the axial transmission side surface 31 b of the core 31 toward the axial transmission side. This may be considered that the axial transmission side surface 31b of the core 31 is located closer to the axial engine side than the axial transmission side edge 30b of the blade 30. The axial engine side edge 30 a of the blade 30 coincides with the axial engine side surface 31 a of the core 31. That is, the axial dimension S1 of the blade 30 is larger than the axial dimension S2 of the core 31. This ratio (S2 / S1) is preferably in the range of 0.6 to 0.9. When the ratio (S2 / S1) is 0.6 or less, if the core 31 is too small for the blade 30 to correct the balance, or if the core 31 is of a certain size, the blade 30 is in the core 31. On the other hand, the result is that the length of the fluid can be rectified and the resistance to the fluid is increased. If the ratio (S2 / S1) exceeds 0.9, the core 31 disturbs the flow of hydraulic oil flowing from the stator 20 to the impeller 18.

Relationship between Blade 30 and Torus 6 An axial position C2 of the center of each blade 30 in the axial direction is an axial position C1 of an axial boundary between the impeller 18 and the turbine 19 in the torus 6 (the outlet of the impeller 18 and the inlet of the turbine 19). (Center of the axial direction between) and the axial transmission side, that is, the impeller 18 side. This is because when the axial dimension of the turbine 19 is shortened and the turbine 19 outlet is closer to the impeller 18 inlet than in the prior art, the blades 30 are moved away from the turbine 19 outlet and are less likely to interfere with each other. Further, the axial engine side edge 30a of the blade 30, that is, the turbine side edge protrudes from the axial position C1 to the axial engine side by the axial protrusion amount S3, but the protrusion amount S3 is 5 mm or less.

The core structure impeller 18 has an annular impeller core 37 fixed to the turbine side of the impeller blade 23. The turbine 19 has an annular turbine core 38 fixed to the impeller side of the turbine blade 26. The tip of the inner peripheral end of the impeller core 37 is positioned on the axial transmission side from the tip of the outer peripheral end, and the tip of the inner peripheral end of the turbine core 37 is positioned on the axial transmission side of the outer peripheral end. Both the inner peripheral portions of the impeller core 37 and the turbine core 38 protrude in the axial direction from the blade 23 and the blade 26, respectively, and are disposed on the outer peripheral side of the stator core 31. More specifically, the inner peripheral end of the impeller core 37 extends toward the axial engine side, the inner peripheral end of the turbine core 38 extends toward the axial transmission side, and the tips are close to each other. The tip of the inner peripheral end of the turbine core 38 is located closer to the axial transmission side than the axial position C1.

(2) Structure of lockup device Next, the lockup device 7 will be described. The lockup device 7 is mainly composed of a piston member 44 and a damper mechanism 45. The piston member 44 is a disk-shaped member that is disposed close to the axial engine side of the front cover 14. The piston member 44 is a recess that is narrowed so that the radially intermediate portion protrudes toward the axial transmission side. The front cover 14 is formed with an annular recess corresponding to the recess of the piston member 44. An inner peripheral cylindrical portion 48 extending toward the axial transmission side is formed on the inner peripheral portion of the piston member 44. The inner peripheral cylindrical portion 48 is supported on the outer peripheral surface of the turbine hub 27 so as to be capable of relative rotation and axial movement. The axial transmission side end portion of the inner peripheral cylindrical portion 48 is in contact with the flange portion of the turbine hub 27, so that the movement toward the axial transmission side is limited to a predetermined position. A seal ring 49 is disposed on the outer peripheral surface of the turbine hub 27, and the seal ring 49 seals an axial space in the inner peripheral portion of the piston member 44.

  The outer peripheral portion of the piston member 44 functions as a clutch coupling portion. An annular friction facing 46 is fixed on the engine side of the outer periphery of the piston member 44. The friction facing 46 is opposed to an annular and flat friction surface formed on the inner surface of the outer peripheral portion of the front cover 14. A plurality of protrusions 47 extending toward the axial transmission side are formed on the outer periphery of the piston member 44.

  The damper mechanism 45 includes a drive member 52, a driven member 53, and a plurality of torsion springs 54 (elastic connecting portions). The drive member 52 includes a pair of plate members 56 and 57 arranged side by side in the axial direction. The outer peripheral portions of the pair of plate members 56 and 57 are in contact with each other and are fixed to each other by a plurality of rivets 55. A plurality of protrusions extending in the radial direction so as to engage with the protrusions 47 are formed on the outer peripheral edges of the pair of plate members 56 and 57. By this engagement, the piston member 44 and the drive member 52 can move relative to each other in the axial direction, but rotate together in the rotational direction. The pair of plate members 56 and 57 are arranged such that their inner peripheral portions are spaced apart from each other in the axial direction. A plurality of first and second support portions 56a and 57a arranged in the circumferential direction are formed on the inner peripheral portions of the plate members 56 and 57, respectively. The first and second support portions 56a and 57a have a structure for storing and supporting a torsion spring 54, which will be described later. Specifically, the first and second support portions 56a and 57a are cut and raised portions on both sides in the radial direction cut and raised in the axial direction. The driven member 53 is a disk-shaped member. The driven member 53 is disposed between the axial directions of the first and second plate members 56 and 57, and the inner peripheral portion is fixed to the flange of the turbine hub 27 by a plurality of rivets 28. A window hole 58 is formed in the driven member 53 in correspondence with the first and second support portions 56a and 57a. The window hole 58 is a hole extending long in the circumferential direction. The plurality of torsion springs 54 are accommodated in the window holes 58 and the first and second support portions 56a and 57a. The torsion spring 54 is a coil spring extending in the circumferential direction, and both ends in the circumferential direction are supported by the window holes 58 and the circumferential ends of the first and second support portions 56a and 57a. Further, the axial movement of the torsion spring 54 is limited by the cut and raised portions of the first and second support portions 56a and 57a.

The position of the torsion spring 54 The torsion spring 54 is disposed on the turbine 19 side of the piston member 44, that is, between the piston member 44 and the turbine 19 in the axial direction. For this reason, the coil diameter D of the torsion spring 54 can be increased by the amount by which the axial dimension Lt of the turbine 19 is shorter than the conventional one.

  The torsion spring 54 is disposed on the inner peripheral side from the outer peripheral portion that is the clutch connecting portion of the piston member 44. Further, the torsion spring 54 is located on the engine side of the inner peripheral portion of the turbine 19. The radial center position of the torsion spring 54 is located further on the inner peripheral side than the radial center of the torus 6. The torsion spring 54 is disposed in the annular recess of the piston member 44. That is, the axial engine side edge of the torsion spring 54 is located further on the axial engine side than the friction facing 46 of the piston member 44. In this way, in the lockup device 7 using the piston member 44 close to the front cover 14, the torsion spring 54 is not arranged on the transmission side of the outer peripheral portion of the piston member 44. Therefore, the coil diameter D of the torsion spring 54 is made larger than before. can do.

  Here, in particular, since the axial dimension Lt of the turbine 19 is shorter than before, the coil diameter D of the torsion spring 54 can be made sufficiently large. The coil diameter D of the torsion spring 54 is close to or comparable to the axial dimension Lt of the turbine 19. More specifically, the ratio (D / Lt) is 0.85 or more, preferably in the range of 0.85 to 1.0. Since the coil diameter D of the torsion spring 54 constituting the damper mechanism 45 of the lockup device 7 can be increased in this way, it is easy to improve the performance of the torsion spring 54. As a result, it is actually possible to use the fluid torque transmission by the torus 6 of the torque converter 1 only at the time of starting, and thereafter use the lockup device 7 in the activated state. If the torsion spring 54 cannot be enlarged sufficiently, there arises a problem that the torsional vibration cannot be sufficiently absorbed if the lockup region is expanded to a low speed.

  As described above, in the torque converter 1, the torsion spring 54 of the lockup device 7 can be made sufficiently large in the axial direction, and the damper function of the lockup device 7 can be improved. That is, it is possible to provide a lockup device having an excellent damper function in a torque converter having a flattened and asymmetric torus.

(3) Operation When torque is transmitted from the engine (not shown) to the crankshaft 2, the torque is transmitted to the front cover 14 and the impeller 18 via the flexible plate 4. The hydraulic oil driven by the impeller blades 23 of the impeller 18 rotates the turbine 19. The torque of the turbine 19 is output to an input shaft (not shown) via the turbine hub 27. The hydraulic fluid flowing from the turbine 19 to the impeller 18 flows to the impeller 18 side through a passage determined by the carrier 29 and the core 31 of the stator 20.

  Here, in the ultra-flat and asymmetric torus 6, the axial transmission side edge 30 b of the blade 30 protrudes further to the axial transmission side than the axial transmission side surface 31 b of the core 31, so that the portion flows from the blade 30 to the impeller 18. In this case, the problem that the hydraulic oil is disturbed by the core 31 hardly occurs. That is, since the core 31 has a shape retracted toward the axial engine side with respect to the blade 30, the hydraulic oil flows smoothly. Further, since the blade 30 is arranged to be shifted to the transmission side with respect to the axial position C1 at the boundary between the impeller 18 and the turbine 19, the turbine 19 and the stator 20 are unlikely to interfere with each other.

  Furthermore, since the axial engine side edge 30a of the blade 30 protrudes only slightly relative to the boundary axial position C1, interference between the turbine 19 and the stator 20 is further less likely to occur. Furthermore, since the ratio between the axial dimension S1 of the blade 30 and the axial dimension S2 of the core 31 is set in an appropriate range, the performance of the stator 20 is improved.

  When the hydraulic fluid in the space between the front cover 14 and the piston member 44 is drained from the inner peripheral side, the piston member 44 moves to the front cover 14 side due to the hydraulic pressure difference, and the friction facing 46 is brought to the friction surface of the front cover 14. Pressed. As a result, torque is transmitted from the front cover 14 to the turbine hub 27 via the lockup device 7. Here, since the performance of the torsion spring 54 is improved as described above, the torsional vibration can be sufficiently suppressed even when the lockup connection is performed from the low speed region.

The longitudinal cross-sectional schematic of the torque converter as embodiment of this invention. Schematic which shows the relationship between the stator blade of a stator, and a core.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Torque converter 2 Crankshaft 5 Torque converter main body 6 Torus 7 Lockup apparatus 18 Impeller 19 Turbine 20 Stator 29 Carrier 30 Stator blade 31 Core 44 Piston member 45 Damper mechanism 54 Torsion spring H Torus radial dimension L Torus axial dimension Lp Impeller Axial dimension Lt Turbine axial dimension S1 Stator blade axial dimension S2 Core axial dimension S3 Axial protrusion C1 from the torus boundary of the stator blade C1 Boundary C2 between impeller outlet and turbine inlet Axial center of blade 30

Claims (8)

A torque converter for transmitting torque from an engine to a transmission side by fluid,
A front cover that is arranged on the engine side and receives torque from the engine;
An impeller disposed on the transmission side of the front cover, forming a fluid chamber together with the front cover, and provided with a plurality of blades inside;
A turbine disposed in the fluid chamber on the engine side of the impeller, provided with a plurality of blades on a side facing the impeller, and capable of outputting torque to the transmission;
A stator for rectifying the flow of fluid flowing from the turbine to the impeller, disposed between the impeller and an inner periphery of the turbine;
The impeller, turbine and stator constitute a torus;
The torus has a flatness ratio (L / H) which is a ratio of an axial dimension L to a radial dimension H of 0.7 or less,
A shaft dimension Lt of the turbine is shorter than a shaft dimension Lp of the impeller, and a ratio (Lt / Lp) of the shaft dimension Lt to the shaft dimension Lp is in a range of 0.7 to 0.9.
The stator includes an annular carrier, a plurality of blades provided on an outer peripheral surface of the carrier and disposed between the impeller and the turbine, and an annular core fixed to tips of the plurality of blades. And
The plurality of blades have a portion protruding toward the axial transmission side with respect to the core, so that the axial transmission side edge of the plurality of blades is closer to the axial transmission side than the axial transmission side surface of the core. positioned,
Torque converter.   The torque converter according to claim 1, wherein a ratio (S2 / S1) of an axial dimension S2 of the core to an axial dimension S1 of the plurality of blades is in a range of 0.6 to 0.9.   The torque converter according to claim 1 or 2, wherein an axial engine side edge of the plurality of blades coincides with an axial engine side surface of the core in the axial direction.   The torque converter according to any one of claims 1 to 3, wherein an axial center position of the plurality of blades is located closer to an axial transmission side than an axial position between the impeller outlet and the turbine inlet. The axial engine side edges of the plurality of blades are located closer to the axial engine side than the axial position,
The torque converter according to any one of claims 1 to 4, wherein an axial distance S3 between an axial engine side edge of the plurality of blades and the axial position is 5 mm or less. The impeller includes an impeller shell, an impeller blade fixed to the impeller shell, and an impeller core fixed to the impeller blade.
The turbine has a turbine shell, a turbine blade fixed to the turbine shell, and a turbine core fixed to the turbine blade,
The inner peripheral end tip of the impeller core is located on the axial transmission side from the outer peripheral end tip,
The torque converter according to any one of claims 1 to 5, wherein a tip of an inner peripheral end portion of the turbine core is positioned closer to an axial transmission side than a front end of the outer peripheral portion. The turbine has a turbine shell, a turbine blade fixed to the turbine shell, and a turbine core fixed to the turbine blade,
The torque converter according to any one of claims 1 to 5, wherein an inner peripheral end portion of the turbine core protrudes from the turbine blade toward an axial transmission side and is disposed on an outer peripheral side of the stator core.   The torque converter according to claim 7, wherein a tip of the inner peripheral end of the turbine core is located closer to an axial transmission side than an axial position between the impeller outlet and the turbine inlet.

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