Starting device and damper device for use therein

A starting device includes: a lock-up clutch mechanism; a fluid coupling; a spring damper including a spring, a power transfer portion transferring power from the lock-up clutch mechanism to the spring, and a power output portion transferring power from the spring to an input shaft; and a pendulum damper including a pendulum and a pendulum power transfer portion transferring power from the spring damper to the pendulum. The output portion of the lock-up clutch, the pendulum damper, the spring damper, and the fluid coupling are arranged sequentially in this order from a motor in the axial direction. The lock-up clutch mechanism output and the spring damper output are connected to each other on the outer circumferential side of the pendulum damper, and the spring damper output and the pendulum power transfer portion are connected to each other on the inner circumferential side of the pendulum.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2010-221024 filed on Sep. 30, 2010 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a starting device that is disposed between a motor and a transmission.

DESCRIPTION OF THE RELATED ART

Hitherto, there has been known a configuration in which a damper device that relieves and absorbs impact torque or the like is disposed on a motor side with respect to a turbine runner of a starting device in the axial direction (see Japanese Patent Application Publication No. 2009-243536, for example). In such a configuration, however, a space on the outer circumferential side of the turbine runner creates a dead space, and may not be utilized effectively.

In order to effectively utilize such a dead space, there has been developed a configuration in which a new damper forming element is disposed in a space on the outer circumferential side of a turbine runner so as to partially overlap the turbine runner in the axial direction (see International Patent Application Publication No. 2010/000220 (FIG. 1), for example).

SUMMARY OF THE INVENTION

In the configuration described in International Patent Application Publication No. 2010/000220, the new damper forming element is provided adjacently on the turbine runner side with respect to a centrifugal pendulum damper in the axial direction, and a power transfer path from a lock-up clutch to the new damper forming element passes through the inner circumferential side of the centrifugal pendulum damper. In such a configuration, it is necessary to form a space for securing the movable range of the new damper forming element in a member (damper plate) that supports a pendulum of the centrifugal pendulum damper, which is disadvantageous in terms of strength. In addition, the movable range of the pendulum of the centrifugal pendulum damper is constrained by a need to prevent interference between the pendulum and a coupling member that forms the power transfer path from the lock-up clutch to the new damper forming element. Thus, the degree of freedom in design (such as mass and arrangement, for example) of the pendulum of the centrifugal pendulum damper may be low.

It is therefore an object of the present invention to provide a starting device which enables improvement of the strength of a damper plate and so forth and the degree of freedom in design of a pendulum of a centrifugal pendulum damper while effectively utilizing a space on the outer circumferential side of a turbine runner.

In order to achieve the foregoing object, an aspect of the present invention provides a starting device including:

a lock-up clutch mechanism that mechanically transfers power from a motor to an input shaft of a transmission;

a fluid coupling including a turbine runner and a pump impeller to transfer power from the motor to the input shaft via a fluid;

a spring damper including a spring, a power transfer portion that transfers power from an output portion of the lock-up clutch mechanism to the spring, and a power output portion that transfers power of the spring to the input shaft; and

a pendulum damper including a pendulum and a pendulum power transfer portion that transfers power from the power output portion of the spring damper to the pendulum, wherein

the output portion of the lock-up clutch mechanism, the pendulum damper, the spring damper, and the fluid coupling are arranged sequentially in this order from the motor in an axial direction, and

the output portion of the lock-up clutch mechanism and the power transfer portion of the spring damper are connected to each other on an outer circumferential side of the pendulum damper, and the power output portion of the spring damper and the pendulum power transfer portion are connected to each other on an inner circumferential side of the pendulum.

According to the aspect of the present invention, a starting device which enables improvement of the strength of a damper plate and so forth and the degree of freedom in design of a pendulum of a centrifugal pendulum damper while effectively utilizing a space on the outer circumferential side of a turbine runner can be provided.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1is a cross-sectional view showing the configuration of an essential portion of a starting device1according to Reference Example 1. InFIG. 1, the upper half of a cross section of the starting device1(the upper half above an input shaft10) is shown. In the following description, the term “axial direction” refers to the direction of the input shaft10of a transmission (the left-right direction ofFIG. 1), and the term “radial direction” refers to the radial direction around the input shaft10of the transmission (the direction perpendicular to the input shaft10; the up-down direction ofFIG. 1, for example) as viewed along the input shaft10of the transmission. Thus, the term “radially outer side” or “outer circumferential side” refers to the side away from the input shaft10in the direction perpendicular to the input shaft10, and the term “radially inner side” refers to the side toward the input shaft10in the direction perpendicular to the input shaft10.

The starting device1is also referred to a “torque converter”, and disposed between a motor and the transmission of a vehicle. The motor is typically any type of engine. The starting device1outputs power input from the motor to the input shaft10of the transmission. The power input to the input shaft10of the transmission is transferred to a propeller shaft via a planetary gear unit, for example. The transmission may be of any type such as an automatic transmission (AT) and a continuously variable transmission (CVT).

The starting device1includes, as its main constituent elements, a front cover20, a pump impeller30, a turbine runner40, a turbine hub50, a stator60, a lock-up clutch mechanism70, and a damper device100.

The front cover20is an input member of the starting device1, and is connected to the motor (not shown) positioned on the right side ofFIG. 1. That is, the front cover20receives power from the motor via a drive plate (not shown). The front cover20is connected to the pump impeller30in a manner that enables transfer of rotational torque to the pump impeller30. Specifically, as shown inFIG. 1, an end portion of an outer circumferential wall of the front cover20is fixed to an edge portion of the pump impeller30on the radially outer side. The pump impeller30includes a plurality of blades30a.

The turbine hub50is an output member of the starting device1, and is connected (for example, splined) to the input shaft10of the transmission. The turbine runner40is connected to the turbine hub50. More specifically, a radially inner end portion of a runner shell42of the turbine runner40is connected to the turbine hub50via a second damper plate142in a manner that enables transfer of rotational torque to the turbine hub50. The turbine runner40includes a plurality of blades40athat face the plurality of blades30aof the pump impeller30in the axial direction. The stator60, which includes a plurality of blades60a, is disposed between the turbine runner40and the pump impeller30. The stator60is supported by a one-way clutch64so as to be rotatable only in one direction about the input shaft10.

The lock-up clutch mechanism70includes a piston (clutch plate)71, a radially inner end portion of which is supported by the turbine hub50, and a lock-up clutch74provided radially outwardly of the piston71. The piston71is slidably supported by the turbine hub50, and is rotatable about the input shaft10. The piston71is also movable along the axial direction. The lock-up clutch74produces a friction force with the front cover20when the lock-up clutch mechanism70is actuated. The lock-up clutch mechanism70may be actuated by a flow of a fluid. Specifically, when the lock-up clutch mechanism70is not actuated, the piston71is pulled away from the front cover20by the flow of the fluid so that no friction force is produced by the lock-up clutch74. When the lock-up clutch mechanism70is actuated, the flow of the fluid is reversed by switching a control valve (not shown) so that the piston71and the lock-up clutch74are pressed toward the front cover20. This causes the lock-up clutch74to produce a friction force, which causes the piston71to rotate about the input shaft10together with the front cover20.

The damper device100is disposed between the lock-up clutch mechanism70and the turbine hub50. The damper device100relieves and absorbs impulsive input torque and torque fluctuations transferred from the lock-up clutch74to the turbine hub50when the lock-up clutch mechanism70is actuated. The configuration of the damper device100will be described in detail later.

The outline of an operation of the starting device1will be described. When an engine operates, the front cover20and the pump impeller30are rotated accordingly. When the pump impeller30is rotated, a fluid near the center of the pump impeller30is urged toward the turbine runner40along the blades30aand the wall to cause the turbine runner40to start rotating. The stator60is stationary when the difference in rotational speed between the pump impeller30and the turbine runner40is large. Thus, the stator60varies the direction of the fluid, and increases rotational torque as rotation of the pump impeller30accelerates (converter range). When the rotational speed of the turbine runner40becomes higher, on the other hand, the stator60idles by the action of the one-way clutch64not to hinder the flow of the fluid (coupling range). Thus, the stator60transfers rotational torque as it is to the turbine runner40when the difference in rotational speed between the pump impeller30and the turbine runner40is small.

In the case where the rotational speed of the turbine runner40becomes higher and predetermined conditions are met (for example, in the case where the vehicle speed reaches a predetermined speed, or in the case where the stator60starts idling (coupling range)), the lock-up clutch mechanism70is actuated. When the lock-up clutch mechanism70is actuated, power transmitted from the motor to the front cover20is mechanically transferred to the turbine hub50as discussed above. That is, the power transmitted from the motor to the front cover20is mechanically transferred from the lock-up clutch74to the turbine hub50via the damper device100. In this event, the damper device100absorbs fluctuations in torque transferred from the front cover20to the turbine hub50.

Next, the configuration of the damper device100will be described in detail with reference toFIGS. 1 and 2.FIG. 2is a perspective view showing a connection portion between the piston71and a first damper120shown inFIG. 1.

As shown inFIG. 1, the damper device100includes the first damper120and a second damper140.

The first damper120is at least partially provided in a space90(hereinafter referred to as “dead space90”) on the outer circumferential side of the turbine runner40. In the dead space90, the first damper120at least partially overlap the turbine runner40in the axial direction. In Reference Example 1, as shown inFIG. 1, a part of a first spring124of the first damper120(a portion on the turbine runner40side in the axial direction) is disposed in the dead space90to overlap the turbine runner40in the axial direction. Here, as shown inFIG. 1, the dead space90may be defined as a space defined by a plane S1extending in the radial direction and including a point P of the turbine runner40that is closest to the motor in the axial direction, the runner shell42of the turbine runner40, and the inner surface of the starting device1(in Reference Example 1, the inner surface of an impeller shell of the pump impeller30). It should be particularly noted that the point P is provided on a portion of the turbine runner40that is convexly curved toward the motor (a portion formed with the blades40a), and not provided on a portion of the turbine runner40for attachment on the turbine hub50side.

The first damper120is provided between the lock-up clutch74and the second damper140from the viewpoint of power transfer path. The first damper120receives power from the lock-up clutch74to transfer the power to the second damper140.

The first damper120includes a first damper plate122and the first spring124. As shown inFIG. 1, the first damper plate122has a generally disk-like shape with a hole provided on the radially center side. The first damper plate122includes a spring holding portion122athat holds the first spring124, a radially inner end portion122c, and an outer circumferential edge portion123on the radially outer side. The radially inner end portion122cof the first damper plate122is held between the runner shell42of the turbine runner40and the second damper plate142of the second damper140in the axial direction. With such a support structure, the radially inner end portion122cof the first damper plate122is centrally aligned to facilitate assembly with the first damper plate122appropriately centrally aligned with respect to the axis of the turbine hub50.

As shown inFIGS. 1 and 2, the outer circumferential edge portion (power transfer portion)123of the first damper plate122is connected to an outer circumferential edge portion72of the piston71in a manner that enables transfer of rotational torque. As shown inFIG. 1, the outer circumferential edge portion123of the first damper plate122and the outer circumferential edge portion72of the piston71extend in the axial direction so as to surround the second damper140from the radially outer side. As shown inFIG. 2, the outer circumferential edge portion123of the first damper plate122includes a plurality of teeth123athat project in the axial direction toward the piston71. The plurality of teeth123aare arranged at predetermined intervals along the circumferential direction of the outer circumferential edge portion123. Correspondingly, as shown inFIG. 2, the outer circumferential edge portion72of the piston71includes a plurality of teeth72athat project in the axial direction toward the first damper plate122. The plurality of teeth72aare arranged at predetermined intervals along the circumferential direction of the outer circumferential edge portion72. The plurality of teeth123aof the first damper plate122of the first damper120are respectively arranged to be fitted between the plurality of teeth72aof the piston71. Thus, the first damper plate122of the first damper120and the piston71are connected to each other with the plurality of teeth123aof the first damper plate122of the first damper120and the plurality of teeth72aof the piston71meshing with each other. The plurality of teeth123aof the first damper plate122of the first damper120and the plurality of teeth72aof the piston71mesh with each other with backlash (clearance) in the circumferential direction. Such backlash is provided to allow the radially inner end portion122cof the first damper plate122to be held between the runner shell42of the turbine runner40and the second damper plate142of the second damper140.

Preferably, as shown inFIG. 2, a stopper movable space92is formed in a part of spaces between (a plurality of) adjacent teeth72aof the piston71. That is, in the illustrated example, a local toothless portion is provided among the plurality of teeth123aof the first damper plate122of the first damper120for the plurality of teeth72aof the piston71, and the stopper movable space92is formed for the toothless portion. The function of the stopper movable space92will be discussed later.

The first spring124is disposed generally along the circumferential direction on the first damper plate122of the first damper120. Typically, a plurality of first springs124are disposed generally along the circumferential direction on the first damper plate122of the first damper120. In the illustrated example, the first spring124is held from the turbine runner40side by the spring holding portion122aof the first damper plate122which extends from the outer circumferential edge portion123toward the turbine runner40. An end portion of the first spring124in the circumferential direction is supported by a member122dfixed to the first damper plate122.

The second damper140includes the second damper plate142, a third damper plate145, an intermediate plate146, a second spring147, and a third spring148.

The second damper plate142is disposed on the turbine runner40side in the axial direction with respect to the third damper plate145. The second damper plate142and the third damper plate145have a generally disk-like shape with a hole provided on the radially center side. The second damper plate142and the third damper plate145are connected to the intermediate plate146so as to be relatively rotatable about the axis of the turbine hub50with respect to the intermediate plate146. Specifically, the second damper plate142and the third damper plate145are fixed to each other by a rivet170. A cylindrical sleeve172is mounted on the rivet170. The sleeve172secures the movable range of the intermediate plate146.

The second damper plate142includes a spring engagement hook143provided at the radially outer end portion to project toward the turbine runner40in the axial direction. The spring engagement hook143engages, in the circumferential direction, with a circumferential end portion (seat portion) of the first spring124of the first damper120. The second damper plate142receives power from the first damper120via the spring engagement hook143.

A stopper portion144extending radially outward is formed as an optional component at the outer circumferential edge portion of the second damper plate142. As shown inFIG. 2, the stopper portion144extends into the stopper movable space92defined along the circumferential direction between the adjacent teeth72aof the piston71. The stopper movable space92prescribes the movable range of the stopper portion144along the circumferential direction. Thus, rotation of the second damper plate142is restrained with the stopper portion144abutting, in the circumferential direction, against one of the adjacent teeth72aof the piston71defining the stopper movable space92. Such a mechanical stopper function implemented by the stopper portion144may function for impulsive input that exceeds the normal range, for example.

Such a stopper portion144may be disposed further radially outward. This makes it possible to reduce the rigidity of the damper plates (such as the second damper plate142) provided in the power transfer path when the stopper portion144is in operation. This also makes it possible to efficiently implement the stopper function by utilizing a part of the meshing portion between the plurality of teeth123aof the first damper120and the plurality of teeth72aof the piston71.

The intermediate plate146shown inFIG. 1has a generally disk-like shape with a hole provided on the radially center side as a whole. The intermediate plate146is provided between the second damper plate142and the third damper plate145in the axial direction. A radially inner end portion of the intermediate plate146is connected to the turbine hub50. Thus, the intermediate plate146rotates together with the turbine hub50.

The second spring147and the third spring148are disposed generally along the circumferential direction on the intermediate plate146between the second damper plate142and the third damper plate145in the axial direction. Typically, a plurality of second springs147and a plurality of third springs148are disposed along the circumferential direction. The second spring147is disposed radially outwardly of the third spring148. In the illustrated example, the second spring147is disposed at a radial position between the third spring148and the first spring124of the first damper120in the radial direction. In addition, the second spring147is disposed on the motor side in the axial direction with respect to the first spring124of the first damper120. Thus, the second spring147is not positioned in the dead space90discussed above. The positional relationship among the first, second, and third springs124,147, and148may be determined on the basis of the position of the center axis of each spring (coil center axis) as viewed in cross section. The second spring147and the third spring148demonstrate their elastic/damping action on relative rotation of the second damper plate142and the third damper plate145with respect to the intermediate plate146about the axis of the turbine hub50. The second spring147and the third spring148may be different from each other in configuration (such as elastic and physical characteristics). The second spring147and the third spring148may be configured to act in different stages during relative rotation of the second damper plate142and the third damper plate145with respect to the intermediate plate146about the axis of the turbine hub50.

In the damper device100, power from the lock-up clutch74is transferred from the outer circumferential edge portion72of the piston71to the first damper120(the outer circumferential edge portion123of the first damper plate122). The power received from the outer circumferential edge portion123of the first damper plate122is transferred to the second damper140(the spring engagement hook143of the second damper plate142) via the first spring124of the first damper120. The power received from the spring engagement hook143of the second damper plate142is transferred to the intermediate plate146of the second damper140and the turbine hub50via the second spring147and the third spring148. In this way, power is transferred from the lock-up clutch74to the turbine hub50via the damper device100.

The damper device100according to Reference Example 1 includes two dampers, namely the first damper120and the second damper140. Thus, a damper device with a capacity high enough to absorb relatively large torque fluctuations (for example, relatively large torque fluctuations produced by a motor with a high output) can be achieved.

In Reference Example 1, in particular, the first damper120is at least partially disposed in the dead space90as discussed above. More specifically, as shown inFIG. 1, a part of the first spring124of the first damper120(a portion on the turbine runner40side in the axial direction) is disposed in the dead space90. Thus, the capacity of the damper device100can be enhanced while effectively utilizing the dead space90which is normally not used. In addition, the length of the starting device1in the axial direction can be efficiently reduced compared to a configuration in which the capacity of the damper device100is enhanced without using the dead space90. The first spring124of the first damper120can be disposed further radially outward by utilizing the dead space90. This makes it possible to reduce the elastic coefficient of the first spring124, and to reduce the rigidity of the various damper plates (such as the first damper plate122and the second damper plate142).

In Reference Example 1, the power transfer path from the lock-up clutch74to the first damper120passes through the radially outer side with respect to the second damper140. More specifically, the power transfer path from the lock-up clutch74to the first damper120passes through the outer circumferential edge portion72of the piston71and then the outer circumferential edge portion123of the first damper plate122to reach the turbine runner40side with respect to the second damper140in the axial direction. That is, the power transfer path from the lock-up clutch74to the first damper120extends from the lock-up clutch74side to the turbine runner40side across the second damper140in the axial direction by passing through the radially outer side with respect to the second damper140without penetrating through the constituent elements of the second damper140in the axial direction. Here, in the case where the power transfer path from the lock-up clutch74to the first damper120penetrates through the power transfer path in the second damper140in the axial direction, as discussed above in relation to Patent Document 2 mentioned above, it is necessary to form a space for securing the movable range of the first damper120in the constituent elements of the second damper140, which is disadvantageous in terms of strength. In Reference Example 1, in contrast, it is not necessary to form a space (such as a sleeve) for securing the movable range of the first damper120in the constituent elements of the second damper140, which makes it possible to improve the strength of the second damper plate142of the second damper140and so forth. In Reference Example 1, in addition, the power transfer path from the lock-up clutch74to the first damper120passes through the radially outer side with respect to the power transfer path in the second damper140.

FIG. 3is a cross-sectional view showing the configuration of an essential portion of a starting device2according to Reference Example 2. InFIG. 3, the upper half of a cross section of the starting device2(the upper half above the input shaft10) is shown. The starting device2according to Reference Example 2 is different from the starting device1according to Reference Example 1 discussed above mainly in how to hold the first spring124. InFIG. 3, constituent elements of the starting device2according to Reference Example 2 that may be identical to those of the starting device1according to Reference Example 1 discussed above are given the same reference numerals to omit their descriptions. A damper device1000of the starting device2according to Reference Example 2 will be mainly described below.

The starting device2includes the damper device1000. As shown inFIG. 3, the damper device1000includes a first damper1200and a second damper1400.

The first damper1200is provided in the space90(dead space90) on the outer circumferential side of the turbine runner40so as to partially overlap the turbine runner40in the axial direction.

The first damper1200includes a damper input member1202and the first spring124. As shown inFIG. 3, the damper input member1202has a generally disk-like shape with a hole provided on the radially inner side. The damper input member1202includes an outer circumferential edge portion1204and a spring engagement hook1206that is provided on the radially inner side.

As shown inFIG. 3, the outer circumferential edge portion (power transfer portion)1204of the damper input member1202is connected to the outer circumferential edge portion72of the piston71in a manner that enables transfer of rotational torque. As shown inFIG. 3, the outer circumferential edge portion1204of the first damper1200and the outer circumferential edge portion72of the piston71extend in the axial direction so as to surround the second damper1400from the radially outer side. The outer circumferential edge portion1204of the first damper1200may be connected to the outer circumferential edge portion72of the piston71in the same manner of connection between the outer circumferential edge portion123of the first damper plate122and the outer circumferential edge portion72of the piston71in the starting device1according to Reference Example 1 discussed above (that is, with their teeth facing each other in the axial direction meshing with each other as shown inFIG. 2). Preferably, however, teeth1204aof the outer circumferential edge portion1204of the first damper1200and the teeth72aof the piston71(seeFIG. 2) mesh with each other with no backlash (clearance) in the circumferential direction. This is because the damper input member1202according to Reference Example 2 is not supported at its radially inner end portion unlike the first damper plate122according to Reference Example 1 discussed above.

The spring engagement hook1206of the first damper1200extends toward the turbine runner400in the axial direction to engage, in the circumferential direction, with an end portion of the first spring124of the first damper1200in the circumferential direction.

The second damper1400includes the second damper plate142, the third damper plate145, the intermediate plate146, the second spring147, and the third spring148. A spring holding plate142athat holds the first spring124of the first damper1200is fixed to the second damper plate142. The spring holding portion142amay be formed integrally with the second damper plate142, or may be fixed to the second damper plate142. The spring holding plate142ais formed in a curved shape to hold the first spring124from the turbine runner40side. The spring holding plate142aengages, in the circumferential direction, with an end portion of the first spring124of the first damper1200in the circumferential direction. The second damper plate142receives power from the first damper1200via the spring holding plate142a.

In the damper device1000, power from the lock-up clutch74is transferred from the outer circumferential edge portion72of the piston71to the first damper120(the outer circumferential edge portion1204of the damper input member1202). The power received from the outer circumferential edge portion1204of the damper input member1202is transferred to the second damper1400(the spring holding plate142afixed to the second damper plate142) via the first spring124of the first damper120. The power received from the spring holding plate142ais transferred to the intermediate plate146of the second damper1400and the turbine hub50via the second spring147and the third spring148. In this way, power is transferred from the lock-up clutch74to the turbine hub50via the damper device1000.

The damper device1000according to Reference Example 2 includes two dampers, namely the first damper1200and the second damper1400. Thus, a damper device with a capacity high enough to absorb relatively large torque fluctuations (for example, relatively large torque fluctuations produced by a motor with a high output) can be achieved.

In Reference Example 2, in particular, the first damper1200is at least partially disposed in the dead space90as discussed above. More specifically, as shown inFIG. 3, a part of the first spring124of the first damper1200(a portion on the turbine runner40side in the axial direction) is disposed in the dead space90. Thus, the capacity of the damper device1000can be enhanced while effectively utilizing the dead space90which is normally not used. In addition, the length of the starting device2in the axial direction can be efficiently reduced compared to a configuration in which the capacity of the damper device1000is enhanced without using the dead space90. The first spring124of the first damper1200can be disposed further radially outward by utilizing the dead space90. This makes it possible to reduce the elastic coefficient of the first spring124, and to reduce the rigidity of the various damper plates (such as the damper input member1202, the second damper plate142, and the spring holding plate142a).

In Reference Example 2, the power transfer path from the lock-up clutch74to the first damper1200passes through the radially outer side with respect to the second damper1400. More specifically, the power transfer path from the lock-up clutch74to the first damper1200passes through the outer circumferential edge portion72of the piston71and then the outer circumferential edge portion1204of the damper input member1202to reach the turbine runner40side with respect to the second damper140in the axial direction. That is, the power transfer path from the lock-up clutch74to the first damper1200extends from the lock-up clutch74side to the turbine runner40side across the second damper1400in the axial direction by passing through the radially outer side with respect to the second damper1400without penetrating through the constituent elements of the second damper1400in the axial direction. Thus, it is not necessary to form a space for securing the movable range of the first damper1200in the constituent elements of the second damper1400, which makes it possible to improve the strength of the second damper plate142of the second damper1400and so forth. In Reference Example 2, in addition, the power transfer path from the lock-up clutch74to the first damper1200passes through the radially outer side with respect to the power transfer path in the second damper1400.

FIG. 4is a cross-sectional view showing the configuration of an essential portion of a starting device3according to an embodiment (a first embodiment). InFIG. 4, the upper half of a cross section of the starting device3(the upper half above the input shaft10) is shown. The starting device3according to the first embodiment is different from the starting device1according to Reference Example 1 discussed above in the configuration of a second damper240and in including a centrifugal pendulum damper (pendulum damper)247. InFIG. 4, constituent elements of the starting device3according to the first embodiment that may be identical to those of the starting device1according to Reference Example 1 discussed above are given the same reference numerals to omit their descriptions. The peculiar configuration of the starting device3according to the first embodiment will be mainly described below.

The starting device3includes a damper device200. As shown inFIG. 4, the damper device200includes a first damper220, the second damper240, and the centrifugal pendulum damper247.

The first damper220is provided in the space90(dead space90) on the outer circumferential side of the turbine runner40so as to partially overlap the turbine runner40in the axial direction.

The first damper220includes a first damper plate222and the first spring124. As shown inFIG. 4, the first damper plate222has a generally disk-like shape with a hole provided on the radially inner side. The first damper plate222includes an outer circumferential edge portion223and a spring holding portion222athat holds the first spring124.

As shown inFIG. 4, the outer circumferential edge portion (power transfer portion)223of the first damper plate222is connected to the outer circumferential edge portion72of the piston71in a manner that enables transfer of rotational torque. As shown inFIG. 4, the outer circumferential edge portion223of the first damper220and the outer circumferential edge portion72of the piston71extend in the axial direction so as to surround the second damper240from the radially outer side. The outer circumferential edge portion223of the first damper220may be connected to the outer circumferential edge portion72of the piston71in the same manner of connection between the outer circumferential edge portion123of the first damper plate122and the outer circumferential edge portion72of the piston71in the starting device1according to Reference Example 1 discussed above (that is, with their teeth facing each other in the axial direction meshing with each other as shown inFIG. 2). Preferably, however, teeth223aof the outer circumferential edge portion223of the first damper220and the teeth72aof the piston71(seeFIG. 2) mesh with each other with no backlash (clearance) in the circumferential direction. This is because the first damper plate222according to the first embodiment is not supported at its radially inner end portion unlike the first damper plate122according to Reference Example 1 discussed above. The first damper plate222according to the first embodiment may be supported at its radially inner end portion as with the first damper plate122according to Reference Example 1 discussed above. That is, the first damper plate222may be held between the runner shell42of the turbine runner40and the second damper plate142of the second damper240.

The spring holding portion222aof the first damper220is formed in a curved shape to hold the first spring124from the turbine runner40side. The spring holding portion222aengages, in the circumferential direction, with an end portion of the first spring124of the first damper220in the circumferential direction.

The second damper240includes the second damper plate142, the third damper plate145, the intermediate plate146, and the third spring148. The third spring148is disposed on the motor side in the axial direction with respect to the first spring124of the first damper220disposed in the dead space90. Together with a radially inner end portion of the runner shell42, the second damper plate142is fixed, by a rivet270, to a member280that rotates together with the turbine hub50. The second damper plate142and the turbine hub50may be connected to each other in the same manner as in Reference Example 1 discussed above.

The centrifugal pendulum damper247is disposed on the motor side in the axial direction with respect to the first spring124of the first damper220. In the illustrated example, the centrifugal pendulum damper247is disposed radially outwardly of the third spring148, and disposed generally at the same radial position as the first spring124of the first damper120. The centrifugal pendulum damper247produces torque that reacts against torque fluctuations of the motor. That is, the centrifugal pendulum damper247receives power (vibration) from the first spring124of the first damper220, and transfers the power (a reacting force that cancels vibration components of the power) to the turbine hub50via the third damper plate145of the second damper240.

In the illustrated example, the centrifugal pendulum damper247includes a pendulum248and a flange (damper plate)250. The flange250has a flat disk-like shape, and extends generally in parallel with the base surface of the piston71(a portion on the inner circumferential side with respect to the outer circumferential edge portion72). A radially outer portion of the flange250extends generally linearly to form a support portion that supports the pendulum248. A radially inner portion of the flange250is coupled to the third damper plate145by a rivet272. That is, the flange250is coupled to the third damper plate145on the radially inner side of the third spring148.

The pendulum248may be provided at a plurality of locations (for example, four locations) in the circumferential direction of the flange250. As shown inFIG. 4, the pendulums248may be provided on both sides of the flange250in the axial direction. The pendulums248each have a notched groove249for guiding purpose formed in a predetermined shape. A guide pin274is inserted into the notched groove249. The guide pin274has a retaining portion, and is inserted through the flange250and the pendulum248for free rotation to be assembled so as to be rotatable along both a notched groove for guiding purpose formed in a predetermined shape in the flange250and the notched groove249for guiding purpose formed in the pendulum248. In the case where the pendulums248are provided on both side surfaces of the flange250, the clearance between the pendulums248is restrained by a plurality of pendulum coupling members (not shown). Thus, the pendulum248can relatively move in the circumferential direction with respect to the flange250as the guide pin274moves in the circumferential direction along the notched groove249for guiding purpose. The notched groove249for guiding purpose is typically formed such that the radial position of the notched groove249with respect to the input shaft10varies along the circumferential direction rather than formed concentrically with the input shaft10. In this case, the pendulum248relatively moves also in the radial direction with respect to the flange250as the guide pin274moves along the notched groove249for guiding purpose.

In the damper device200, power from the lock-up clutch74is transferred from the outer circumferential edge portion72of the piston71to the first damper220(the outer circumferential edge portion223of the first damper plate222). The power received from the outer circumferential edge portion223of the first damper plate222is transferred to the second damper240(the spring engagement hook143of the second damper plate142) via the first spring124of the first damper220. The power received from the spring engagement hook143of the second damper plate142is subjected to a damping action exerted by the third spring148, and transferred to the turbine hub50. In this way, power is transferred from the lock-up clutch74to the turbine hub50via the damper device200. In addition, torque fluctuations of the motor are damped by the action of the centrifugal pendulum damper247via the third damper plate145of the second damper240.

More specifically, the third damper plate145of the second damper240is integrally coupled to the second damper plate142as discussed above to transfer (input) power from the first damper220to the third spring148of the second damper240in cooperation with the second damper plate142. The intermediate plate146, which serves as an output portion of the second damper240, transfers the power to the turbine hub50. Further, the flange250of the centrifugal pendulum damper247is coupled to the third damper plate145of the second damper240. Thus, the third damper plate145is subjected to a damping action exerted by the pendulum248of the centrifugal pendulum damper247and a damping action exerted by the first spring124of the first damper220. The turbine runner40of a fluid coupling is coupled to intermediate members (damper plates142and145) of the first damper220and the second damper240. Therefore, relatively high vibration is produced because of the weight of the turbine runner40. Vibration of the turbine runner40can be damped by coupling the pendulum damper247to the same intermediate members (damper plates142and145) that the turbine runner40is coupled to, thereby effectively damping torque fluctuations caused by vibration of the motor.

The damper device200according to the first embodiment includes the first damper220, the second damper240, and the centrifugal pendulum damper247. Thus, a damper device with a capacity high enough to absorb relatively large torque fluctuations can be achieved.

In the first embodiment, in particular, the first damper220is at least partially disposed in the dead space90as discussed above. More specifically, as shown inFIG. 4, a part of the first spring124of the first damper220(a portion on the turbine runner40side in the axial direction) is disposed in the dead space90. Thus, the capacity of the damper device200can be enhanced while effectively utilizing the dead space90which is normally not used. In addition, the length of the starting device3in the axial direction can be efficiently reduced compared to a configuration in which the capacity of the damper device200is enhanced without using the dead space90. The first spring124of the first damper220can be disposed further radially outward by utilizing the dead space90. This makes it possible to reduce the elastic coefficient of the first spring124, and to reduce the rigidity of the various damper plates (such as the first damper plate222and the second damper plate142).

In the first embodiment, the power transfer path from the lock-up clutch74to the first damper220passes through the radially outer side with respect to the second damper240and the centrifugal pendulum damper247. More specifically, the power transfer path from the lock-up clutch74to the first damper220passes through the outer circumferential edge portion72of the piston71and then the outer circumferential edge portion223of the first damper plate222to reach the turbine runner40side with respect to the centrifugal pendulum damper247and the second damper240in the axial direction. That is, the power transfer path from the lock-up clutch74to the first damper220extends from the lock-up clutch74side to the turbine runner40side across the centrifugal pendulum damper247and the second damper240in the axial direction by passing through the radially outer side with respect to the centrifugal pendulum damper247and the second damper240without penetrating through the constituent elements of the centrifugal pendulum damper247and the second damper240in the axial direction. Thus, it is not necessary to form a space for securing the movable range of the first damper220in the constituent elements of the centrifugal pendulum damper247and the second damper240, which makes it possible to improve the strength of the respective damper plates of the centrifugal pendulum damper247and the second damper240(such as the second damper plate142). In the first embodiment, in addition, the power transfer path from the lock-up clutch74to the first damper220passes through the radially outer side with respect to the power transfer path in the second damper240.

In the first embodiment, as discussed above, a coupling member (the outer circumferential edge portion72of the piston71) that defines the power transfer path from the lock-up clutch74to the first damper220is disposed radially outwardly of the centrifugal pendulum damper247. Thus, the degree of freedom in movable range of the pendulum248of the centrifugal pendulum damper247can be enhanced compared to a comparative configuration in which such a coupling member passes through the radially inner side of the centrifugal pendulum damper247(penetrates through the flange). Specifically, there is no need to consider interference between the pendulum248of the centrifugal pendulum damper247and the coupling member due to movement of the pendulum248toward the radially inner side with respect to the outer circumferential edge of the flange250of the centrifugal pendulum damper247(that is, relative movement of the pendulum248toward the radially inner side with respect to the flange250due to the shape of the notched groove249for guiding purpose). Thus, the degree of freedom in size and arrangement of the pendulum248of the centrifugal pendulum damper247can be enhanced.

In the first embodiment, as discussed above, the piston71, the centrifugal pendulum damper247, the first damper220, and the fluid coupling (the pump impeller30and the turbine runner40) are arranged sequentially in this order from the motor in the axial direction. Thus, the centrifugal pendulum damper247and the first damper220can be disposed efficiently in a space defined between the piston71and the fluid coupling in the axial direction. For example, if the centrifugal pendulum damper247is disposed on the fluid coupling side and the first damper220is disposed on the piston71side in contrast to the first embodiment, the movable range of the pendulum248of the centrifugal pendulum damper247is significantly restrained. Thus, a limited space can be utilized efficiently by disposing the first damper220, which includes a portion with a curved cross section (for example, the first spring124), in a space with curved boundaries defined on the fluid coupling side and disposing the centrifugal pendulum damper247, which has a generally flat cross section, in a space with planar boundaries defined on the piston71side. Further, the second damper240can also be disposed in the space defined between the piston71and the fluid coupling as with the first damper220. The second damper240may be disposed with the third spring148positioned on the motor side in the axial direction with respect to the first spring124of the first damper220to further enhance the space utilization efficiency.

In Reference Examples 1 and 2 and the first embodiment discussed above, the “fluid coupling” in the claims functions as the pump impeller30and the turbine runner40. The “output portion of a lock-up clutch mechanism” in the claims functions as the piston71(and its outer circumferential edge portion72). The “spring damper” in the claims functions as the first damper220. The “power transfer portion of a spring damper” in the claims functions as the outer circumferential edge portion223of the first damper plate222. The “power output portion of a spring damper” in the claims mainly functions as the second damper plate142, the spring engagement hook143, and the third damper plate145. Here, the second damper plate142, the spring engagement hook143, and the third damper plate145are described as constituent elements of the second damper240in the above description. However, the second damper plate142, the spring engagement hook143, and the third damper plate145also function as output members of the first damper220, and thus can be considered as constituent elements of the first damper220. The “centrifugal pendulum damper” and the “pendulum power transfer portion” in the claims function as the centrifugal pendulum damper247and the flange250, respectively.

Further, the “second spring damper” in the claims functions as the second damper240. The “second power transfer portion” in the claims mainly functions as the spring engagement hook143. The “second power output portion” in the claims functions as the intermediate plate146. The “connection portion” in the claims functions as the second damper plate142, the spring engagement hook143, and the third damper plate145.

While embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments discussed above, and various modifications and alternations may be made to the embodiments discussed above without departing from the scope of the present invention.

For example, in Reference Example 1 discussed above, a toothless portion is provided among the plurality of teeth123aof the first damper plate122of the first damper120for the plurality of teeth72aof the piston71, and the stopper movable space92is formed for the toothless portion. However, an inverted configuration may be used. That is, a toothless portion may be provided among the plurality of teeth72aof the piston71for the plurality of teeth123aof the first damper plate122, and the stopper movable space92may be formed for the toothless portion. That is, the stopper movable space92may be formed in a space between adjacent teeth123aof the first damper plate122. This also applies to Reference Example 2 and the first embodiment discussed above.

In Reference Example 1 discussed above, the outer circumferential edge portion123of the first damper plate122and the outer circumferential edge portion72of the piston71are connected to each other with their teeth facing each other in the axial direction meshing with each other as shown inFIG. 2. However, the outer circumferential edge portion123of the first damper plate122and the outer circumferential edge portion72of the piston71may be connected to each other in any other manner of connection, such as spline fitting, that enables relative movement between the outer circumferential edge portion123of the first damper plate122and the outer circumferential edge portion72of the piston71in the axial direction and that enables transfer of rotational torque. This also applies to Reference Example 2 and the first embodiment discussed above.

In Reference Examples 1 and 2 and the first embodiment discussed above, the second damper140,240,1400may have any configuration as long as the second damper140,240,1400receives power from the lock-up clutch74from the first damper120,220,1200to transfer the power to the turbine hub50via a spring or the like. For example, in Reference Examples 1 and 2 discussed above, either one of the second spring147and the third spring148may be dispensed with. Also, in the first embodiment, the second damper240may be dispensed with.

In Reference Examples 1 and 2 and the first embodiment discussed above, components other than the damper device100,200,1000and the piston71may have any configuration as long as the dead space90is provided on the outer circumferential side of the turbine runner40. For example, a configuration in which the stator60is not provided, a configuration in which a multi-plate clutch is used in the lock-up clutch mechanism70, and so forth may be adopted.

In Reference Example 1 discussed above, the first spring124of the first damper120is partially disposed in the dead space90. However, the first spring124of the first damper120may be entirely disposed in the dead space90. Alternatively, conversely, the first spring124of the first damper120may be entirely disposed outside the dead space90(on the motor side with respect to the plane S1). In this case, a part of a member related to the first damper120may be partially disposed in the dead space90. This also applies to Reference Example 2 and the first embodiment discussed above. For example, in the case of Reference Example 1 discussed above, a part of the first damper plate122of the first damper120(in particular, the spring holding portion122a) may be disposed in the dead space90. In the case of Reference Example 2 discussed above, the spring holding plate142amay be disposed in the dead space90. In the case of the first embodiment discussed above, the spring holding portion222aof the first damper plate222may be disposed in the dead space90.