Patent ID: 12259018

EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS

10: CoverM1: First rotor (first motor, auxiliary motor)21: Rotor shaft23: Rotor sleeve231: Radial extension portion233: Axial extension portion235: First circumferential support portionG: Spring guide30: First damper (first torsional damper)31: First cover plate311: Centrifugal side fixing portion313: First spring cover portion315: Second circumferential support portion317: First cover body portion318: Oil dam (shield member)319: First stopper33: First damper spring331: First damper large-diameter spring333: First damper small-diameter spring35: Driven plate351: First neck portion353: Driven body portion355: First stopper accommodation portion357: First binding portion358: First fluid passageway359: First damper side spline37: Baffle plate371: Baffle body portion373: Third binding portion (shield member)375: Third fluid passageway40: First hysteresis device41: First front friction washer43: First rear friction washer45: First elastic washer50: Second damper (second torsional damper)51: Second cover plate53: Second front cover plate531: Second spring cover portion533: Third circumferential support portion535: Second cover body portion537: Second binding portion538: Second fluid passageway55: Second rear cover plate551: Third spring cover portion553: Fourth circumferential support portion555: Third cover body portion57: Second damper spring571: Second damper large-diameter spring573: Second damper small-diameter spring59: Driven hub591: Second neck portion593: Hub body portion595: Second damper side spline70: Inner spline hub71: Engine clutch side spline80: Engine clutchM2: Second rotor (second motor, drive motor)90: Rotor hub

MODE FOR INVENTION

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is not limited to the embodiments disclosed herein, but will be variously changed and implemented in various different forms. The embodiments are provided so that the present invention will be thorough and complete, and also to provide a more complete understanding of the scope of the present invention to those of ordinary skill in the art. Therefore, it should be understood that the present invention is not limited to the embodiments disclosed below, but the configuration of any one embodiment and the configuration of another embodiment can be substituted or added, and the present invention includes all alterations, equivalents, and alternatives that are included in the technical spirit and scope of the present invention.

It should be interpreted that the accompanying drawings are provided only to allow those skilled in the art to easily understand the exemplary embodiments disclosed in the present specification, and the technical spirit disclosed in the present specification is not limited by the accompanying drawings, and includes all alterations, equivalents, and alternatives that are included in the spirit and the technical scope of the present invention. In the drawings, sizes or thicknesses of constituent elements may be exaggerated, increased, or decreased for convenience of understanding, but the protection scope of the present invention should not be restrictively construed.

The terms used in the present specification are used only for the purpose of describing particular examples or embodiments and are not intended to limit the present invention. Further, singular expressions include plural expressions unless clearly described as different meanings in the context. In the present application, the terms “comprises,” “comprising,” “includes,” “including,” “containing,” “has,” “having”, and other variations thereof are inclusive and therefore specify the presence of features, integers, steps, operations, elements, components, and/or combinations thereof disclosed in the specification. That is, in the present application, the terms “comprises,” “comprising,” “includes,” “including,” “containing,” “has,” “having”, and other variations thereof do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or combinations thereof.

The terms including ordinal numbers such as “first,” “second,” and the like may be used to describe various constituent elements, but the constituent elements are not limited by the terms. These terms are used only to distinguish one constituent element from another constituent element.

When one constituent element is described as being “coupled” or “connected” to another constituent element, it should be understood that one constituent element can be coupled or connected directly to another constituent element, and an intervening constituent element can also be present between the constituent elements. When one constituent element is described as being “coupled directly to” or “connected directly to” another constituent element, it should be understood that no intervening constituent element is present between the constituent elements.

When one constituent element is described as being “disposed above” or “disposed below” another constituent element, it should be understood that one constituent element can be disposed directly on another constituent element, and an intervening constituent element can also be present between the constituent elements.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application.

Because a hybrid drive module according to an embodiment is symmetrical with respect to an axis, only the half of the hybrid drive module based on the axis is illustrated for the convenience of illustration. In addition, for the convenience of description, a direction along a longitudinal direction of an axis defining a center of a rotation of the hybrid drive module is defined as an axial direction. That is, a forward/rearward direction or an axial direction is defined as a direction parallel to a rotation axis. A front (forward) means any one direction of a power source, e.g., a direction toward an engine. A rear (rearward) means the other direction, e.g., a direction toward a transmission. Therefore, a front surface means a surface facing forward, and a rear surface means a surface facing rearward.

A radial direction means a direction toward or away from a center of the rotation axis along a straight line passing through the center of the rotation axis on the plane perpendicular to the rotation axis. A direction radially away from the center is referred to as a centrifugal direction, and a direction toward the center is referred to as a centripetal direction.

A peripheral direction or a circumferential direction means a direction surrounding a periphery of the rotation axis. An outer periphery means an outer circumference, and an inner periphery means an inner circumference. Therefore, an outer peripheral surface is a surface facing away from the rotation axis, and an inner peripheral surface is a surface facing the rotation axis.

A circumferential surface means a surface, a normal line of which is directed in a circumferential direction.

First Embodiment

Hereinafter, a first embodiment of a torsional damper according to the present invention and a hybrid drive module, to which the torsional damper is applied, will be described with reference toFIGS.1to4.

In the first embodiment according to the present invention, the hybrid drive module illustrated inFIG.1is configured such that a first motor M1and a second motor M2are installed in a cover10. The first motor M1may serve to start an engine or regenerate a rotational force of the engine to electrical energy, and the second motor M2may provide driving power for moving a vehicle equipped with the corresponding hybrid drive module.

The hybrid drive module includes a rotor shaft21disposed at a front center of the cover10, extending in an axial direction, and connected to the engine.

The rotor shaft21is connected to the cover10by means of a bearing and rotatably supported on the cover10.

The rotor shaft21is integrally connected to a rotor sleeve23. That is, the rotor sleeve23may receive the rotational force from the engine through the rotor shaft21and be rotatably supported on the cover10.

The rotor sleeve23may include a radial extension portion231extending radially outward from the rotor shaft21, and an axial extension portion233extending in the axial direction from a centrifugal end of the radial extension portion231.

The radial extension portion231may extend in a shape substantially corresponding to a shape of the cover10on which the bearing for supporting the rotor shaft21is installed.

A first rotor M1of the first motor is fixedly installed on an outer periphery of the axial extension portion233.

The axial extension portion233may extend rearward from the centrifugal end of the radial extension portion231. Therefore, a space, which may accommodate the torsional damper, is provided rearward of the radial extension portion231and provided radially inside the axial extension portion233on which the first rotor M1is installed.

The second motor M2may be disposed rearward of the first motor M1. The second motor M2is provided on an outer periphery of a rotor hub90, and a second rotor M2of the second motor M2is fixedly installed on the outer periphery of the rotor hub90.

The rotor hub90is connected to an output terminal of the hybrid drive module. Further, the output terminal of the hybrid drive module is connected to a non-illustrated transmission. Therefore, a rotational force of the rotor hub90is transmitted to the transmission through the output terminal. That is, when the second motor M2rotates, a rotational force of the second motor M2is transmitted to the transmission.

The rotor sleeve23is connected to the rotor hub90through an engine clutch80. Therefore, when the engine clutch80does not connect the rotor sleeve23and the rotor hub90, only the rotational force of the second motor M2is transmitted to the output terminal. When the engine clutch80connects the rotor sleeve23and the rotor hub90, both the rotational force of the second motor M2and the rotational force of the engine are transmitted to the output terminal.

The engine clutch80is installed radially inside the rotor hub90. In the first embodiment, an axial position of a front end of the second rotor M2, an axial position of a front end of the rotor hub90, and an axial position of a front end of the engine clutch80are illustrated as being consistent with one another. The first embodiment exemplarily provides a torsional damper structure in which a second damper50of a second embodiment to be described below is not provided. The first embodiment exemplarily provides a structure in which the engine clutch80is disposed as forward as possible in order to ensure the space provided rearward of the rotor hub90.

Although not illustrated, the second rotor M2and the rotor hub90may extend forward further than the engine clutch80. Then, a space, which may accommodate the torsional damper, is further provided forward of the engine clutch80and provided radially inside the rotor hub90on which the second rotor M2is installed. This configuration may provide a space in which the second damper50of the second embodiment to be described below may be accommodated.

The torsional damper may include a first damper30.

In a drive system, the torsional damper is positioned between the rotor sleeve23and the engine clutch80.

The engine clutch80may be locked up or unlocked by being pressed or released by a piston plate (not illustrated) disposed rearward of the engine clutch80. That is, the engine clutch80may be locked up when the piston plate moves forward and presses friction plates of the engine clutch80forward, and the engine clutch80may be unlocked when the piston plate moves rearward and releases the friction plates.

When the piston plate presses the engine clutch80, the torsional damper connected to the engine clutch80may also be affected by a force that presses the engine clutch80forward. Therefore, the torsional damper and the engine clutch80may be connected to splines359and71. Then, the rotation of the torsional damper and/or the rotation of the engine clutch80are restricted relative to each other, but the influence of the axial movement of the engine clutch80on the torsional damper may be minimized.

Because the first damper30is disposed in the cover10of the hybrid drive module connected to the automatic transmission, a wet damper, which is cooled by the transmission oil, may be configured.

The first damper30may be disposed radially inside the first rotor M1. Therefore, it is possible to minimize or almost eliminate a space that the hybrid drive module occupies in the axial direction by the torsional damper.

The first damper30includes a first cover plate31provided at a driving side, a driven plate35provided at a driven side, and a first damper spring33interposed between the driving side and the driven side.

A front side of the first damper spring33is supported by the rotor sleeve23, and a rear side of the first damper spring33is supported by the first cover plate31.

The front side of the first damper spring33is supported by the radial extension portion231of the rotor sleeve23, and a radially outer side of the first damper spring33is supported by the axial extension portion233of the rotor sleeve23.

A spring guide G is interposed between the first damper spring33and the axial extension portion233to prevent the first damper spring33from being in direct contact with the axial extension portion233.

The first damper spring33may be provided as a plurality of first damper springs33disposed in the circumferential direction. With reference toFIG.4, the embodiment exemplarily provides a structure in which four first damper springs are disposed at equal intervals in the circumferential direction. The first damper springs are disposed in an arc shape.

The first damper springs33may include a first damper large-diameter spring331and a first damper small-diameter spring333that define concentricity.

Two opposite ends of the first damper spring33may be supported by the rotor sleeve23and also supported by the first cover plate31.

A plurality of first circumferential support portions235is provided on the rotor sleeve23and each has a rib shape protruding rearward. The plurality of first circumferential support portions235is provided at predetermined positions in the circumferential direction. The plurality of first circumferential support portions235supports the two opposite ends each of the first damper springs33in the circumferential direction. According to the embodiment, eight first circumferential support portions235may be provided.

The first circumferential support portion235is provided at a portion where the radial extension portion231and the axial extension portion233of the rotor sleeve23are connected. The first circumferential support portion235not only reinforces the rigidity of the rotor sleeve23but also supports the first damper spring33in the circumferential direction. In addition, a radial inner surface of the first circumferential support portion235restricts a radial position of a first front friction washer41of a first hysteresis device40to be described below.

The first cover plate31is disposed radially outward of the first damper spring33and connected to the rotor sleeve23. Specifically, the first cover plate31includes a centrifugal side fixing portion311extending radially outward further than the first damper spring33, and the centrifugal side fixing portion311is connected to a rear end of the axial extension portion233of the rotor sleeve23and integrally moves.

The first cover plate31includes a first cover body portion317, a plurality of first spring cover portions313provided radially outside the first cover body portion317and configured to accommodate the first damper springs33, second circumferential support portions315disposed between the first spring cover portions313and configured to support the first damper springs33in the circumferential direction, the centrifugal side fixing portion311extending radially outward from the first spring cover portion313, a first stopper319extending radially inward from the first cover body portion317, and oil dams318radially inward from the first cover body portion317.

The first damper spring33is supported by the first spring cover portion313of the first cover plate31in the rearward direction and the radial direction. With reference toFIG.4, the embodiment exemplarily provides four first spring cover portions313.

The two opposite ends of each of the four first damper springs33are supported by each of the four second circumferential support portions315provided between the four first spring cover portions313. That is, one second circumferential support portion315supports the ends of the two first damper springs33that face each other when the two first damper springs33are adjacent to each other in the circumferential direction.

According to the embodiment, the first damper spring33is supported radially outward by the axial extension portion233of the rotor sleeve23, and the first cover plate31is connected to the axial extension portion233, such that a radius from a rotation center axis to the first damper spring33may be maximally ensured.

The driven plate35includes a driven body portion353having a first stopper accommodation portion355configured to accommodate the first stopper319, a first neck portion351extending radially outward from the driven body portion353, and a first damper side spline359provided at a centripetal side end of the driven body portion353.

The first stopper accommodation portion355and the first stopper319, which is accommodated in the first stopper accommodation portion355, define a range in which the first cover plate31may rotate relative to the driven plate35. The first stopper accommodation portion355may be a long hole having an arc shape. That is, the first cover plate31may rotate relative to the driven plate35by an extra portion made by subtracting a circumferential width of the first stopper319from a length of the long hole of the first stopper accommodation portion355. Then, it is possible to prevent the first damper spring33from being excessively compressed. The first stopper319may be provided as a plurality of first stoppers319, and the first stopper accommodation portions355may also be provided to correspond in number to the first stoppers319. With reference toFIGS.2to4, the embodiment exemplarily provides a configuration in which four first stoppers and four first stopper accommodation portions are provided. Of course, it is apparent that the first stoppers and the first stopper accommodation portions are disposed at equal intervals in the circumferential direction.

The first stopper accommodation portion355is provided in an inclined section of the driven body portion353that extends in the radial direction in a shape inclined with respect to the axial direction. The inclined section may have a shape inclined forward as the driven body portion353extends radially outward. Therefore, the first stopper319may be accommodated in the first stopper accommodation portion355only by simply stacking the first cover plate31and the driven plate35in the axial direction.

The rotor sleeve23may have a flow path through which the transmission oil is supplied to a space provided radially inward of the inclined section. Therefore, oil may be supplied to a radial inner space of the inclined section of the driven body portion353, and the oil may flow radially outward by receiving a centrifugal force by the rotating torsional damper.

Because the first stopper accommodation portion355provided on the driven body portion353is formed in the inclined section, the first stopper accommodation portion355has a shape opened not only in the axial direction but also in the radial direction. Further, the first stopper accommodation portion355is in an opened state in the circumferential direction by a section in which a relative rotation is allowable even in a state in which the first stopper319is accommodated.

The most amount of oil, which flows radially outward from the radial inner space of the inclined section, is discharged through the first stopper accommodation portion355. Then, the oil may flow in a radially outward direction of the first damper30without wetting a portion of the first damper spring33and a portion in the vicinity of the first hysteresis device40where a large amount of friction occurs.

Therefore, in the present invention, a shield member is provided to block the first stopper accommodation portion355to prevent a situation in which the oil is immediately discharged radially outward through the first stopper accommodation portion355as described above. According to the first embodiment, the shield member may be the oil dam318formed radially inside the first cover body portion317.

The oil dam318extends radially inward from the first cover body portion317in a shape corresponding to the shape in which the inclined section of the driven body portion353is inclined with respect to the axial direction. That is, the oil dam318may have a shape inclined rearward as the oil dam318extends radially inward from the first cover body portion317.

Further, the oil dam318is not accommodated in the first stopper accommodation portion355so as not to interfere with the driven plate35. The oil dam318has a shape that is disposed radially outside the first stopper accommodation portion355and covers the first stopper accommodation portion355.

With reference toFIG.4, the oil dams318and the first stoppers319are alternately disposed in the circumferential direction. Therefore, the number of oil dams318corresponds to the number of first stoppers319. The embodiment exemplarily provides a structure in which four oil dams318are provided.

The oil dam318may be formed to cover all the remaining sections, which exclude the section in which the first stopper319is formed, in the circumferential direction. The oil dam318may be provided by cutting an inner end of the driven plate35at a boundary portion between a section, in which the first stopper319is to be provided, and a section, in which the oil dam318is to be provided, and performing processing, such as pressing, on a portion corresponding to the oil dam318. This processing may be performed together with a process of forming the first stopper319, and as a result, the shield member is formed without increasing the number of manufacturing processes.

Then, the oil is mostly guided by the oil dam318except for oil discharged radially outward through a small space opened by the first stopper319, and the oil moves through a space between the radial extension portion231of the rotor sleeve23and the first cover body portion317of the first cover plate31and flows while wetting the first hysteresis device40and the first damper spring33.

The second embodiment to be described below exemplarily provides a shape in which the second damper is further connected in series to the first damper. According to the structure, the oil needs to be supplied not only to the first damper but also to the second damper. According to the above-mentioned structures of the first stopper319and the oil dam318of the first embodiment, the oil, which is supplied to the radial inner space of the inclined section of the driven body portion353, may be supplied to the second damper while being discharged radially outward through a small space opened by the first stopper319. Therefore, in case that the second damper is connected in series to a rear side of the first damper, as in the second embodiment, the amount of oil to be supplied to the first damper and the second damper may be designed by adjusting a width of the first stopper319, a width of the oil dam318, and/or an interval between the first stopper319and the oil dam318.

The first neck portion351may be disposed between the first circumferential support portion235of the rotor sleeve23and the second circumferential support portion315of the first cover plate31in the axial direction.

A circumferential width of the first neck portion351may be slightly smaller than a circumferential width of the second circumferential support portion315. Then, it is possible to provide a free-angle section in which the driven plate35may rotate relative to the first cover plate31without compressing the first damper spring33.

The first damper side spline359engages with an engine clutch side spline71provided on an outer peripheral surface of an inner spline hub70connected to the engine clutch80so that a rotation thereof is restricted. Therefore, the rotation of the first damper30and the rotation of the engine clutch80are restricted in the rotation direction, and the first damper30and the engine clutch80are allowed to relatively slide in the axial direction.

When the rotational force of the engine is transmitted to the first cover plate31through the rotor shaft21and the rotor sleeve23, the first damper spring33, which is supported by the first cover plate31, presses the first neck portion351in the rotation direction and transmits the rotational force to the driven plate35. In this case, the first damper spring33absorbs a non-uniform rotational force of the engine, uniformizes the rotational force to some extent, and then transmits the rotational force to the driven plate35. Then, the output of the engine is uniformized and transmitted to the rotor hub90through the engine clutch80.

According to the embodiment, a free angle is imparted to the first damper30. Therefore, when the rotational force of the engine is transmitted to the torsional damper, the free angle may be consumed, and the rotational force of the engine may be transmitted to the rotor hub90.

With reference toFIG.1, the first hysteresis device is provided in the first damper30of the torsional damper of the embodiment and provides first hysteresis torque to the first damper30. When the hysteresis torque is provided to the damper as described above, an effect of reducing noise may be further improved, and in particular, the effect of reducing noise may be further improved when the engine idles.

The first hysteresis device40includes the first front friction washer41disposed between the radial extension portion231of the rotor sleeve23and the driven body portion353of the driven plate35in the axial direction, a first rear friction washer43disposed between the driven body portion353and the first cover body portion317of the first cover plate31in the axial direction, and a first elastic washer45disposed between the driven body portion353and the first rear friction washer43in the axial direction.

The first rear friction washer43may have a hook portion extending forward while penetrating the driven body portion353, and the hook portion may interfere with a front surface of the driven body portion353. A radial position of the first rear friction washer43is restricted by the driven body portion353.

The radial position of the first elastic washer45is restricted as an outer peripheral surface of the first elastic washer45comes into contact with an inner peripheral surface of the hook portion of the first rear friction washer43.

The first elastic washer45is disposed between the driven plate35and the first rear friction washer43in a state in which a preload is applied. Further, the first hysteresis torque Tl is intuitively determined by the preload of the first elastic washer45.

In this case, the first elastic washer45is disposed rearward of the driven plate35. Then, the first elastic washer45presses the driven plate forward. As illustrated inFIG.1, the driven plate35is disposed at a foremost side with respect to the first cover plate31within an allowable range by the first elastic washer45.

When the engine clutch80is pressed forward by the piston plate, the driven plate35connected to the engine clutch80may receive a forward axial force even though the spline connection is made. However, because the first damper30has been already moved and disposed at the foremost side by the first elastic washer45within the allowable range by the friction washers41and43as described above, the axial force is never transmitted to the first elastic washer45. Therefore, the torsional damper installed in the hybrid drive module of the embodiment consistently applies a designed preload to the driven plate35.

This means that the designed hysteresis torque does not change even under varying operating conditions. That is, according to the embodiment, the first elastic washer45, which provides hysteresis torque to the first damper30, may provide intended hysteresis torque by applying an elastic force to the first damper30in response to a designed preload regardless of whether the engine clutch80operates.

The above-mentioned first embodiment exemplarily provides the single damper shape in which the torsional damper has the first damper30. However, the torsional damper of the first embodiment may, of course, have a damper shape in which the second damper50is further connected in series, as in the second embodiment to be described below.

Second Embodiment

Hereinafter, the second embodiment of the torsional damper according to the present invention will be described with reference toFIGS.5to9. The second embodiment differs from the first embodiment in that the shield member is differently configured, and the second damper is further connected to the first damper in series. Therefore, the description will be focused on the difference.

The torsional damper may further include the second damper50connected in series to the rear side of the first damper30in the drive system. As described above, the low-rigidity design may be implemented when the torsional damper is configured by connecting the first damper30and the second damper50in series.

Like the first damper30, the second damper50is also disposed in the cover10of the hybrid drive module connected to the automatic transmission, such that a wet damper, which is cooled by the transmission oil, may be configured.

The first damper30may be disposed radially inside the first rotor M1, and the second damper50may be provided axially rearward of the first rotor M1and disposed radially inside the second rotor M2. Therefore, it is possible to minimize or almost eliminate the space that the hybrid drive module occupies in the axial direction by the torsional damper.

The first cover plate31includes the first cover body portion317, the plurality of first spring cover portions313provided radially outside the first cover body portion317and configured to accommodate the first damper springs33, the second circumferential support portions315disposed between the first spring cover portions313and configured to support the first damper springs33in the circumferential direction, the centrifugal side fixing portion311extending radially outward from the first spring cover portion313, and the first stopper319extending radially inward from the first cover body portion317.

According to the second embodiment, the oil dam318provided on the first cover plate31of the first embodiment is excluded so that the second damper50is disposed to be closer to the first damper30, such that the second damper50may be disposed to be closer to the first damper30. Therefore, in the second embodiment, in order to prevent an increase in axial dimension of the torsional damper, a baffle plate37, which serves as a shield member configured to block a flow of oil, is attached to the radial inner surface of the inclined section of the driven body portion353of the driven plate35of the first damper30.

The driven plate35includes the driven body portion353having the first stopper accommodation portion355configured to accommodate the first stopper319, the first neck portion351extending radially outward from the driven body portion353, and a first binding portion357provided at the centripetal side end of the driven body portion353.

According to the second embodiment, because the second damper50is connected in series to the rear side of the first damper30, the first binding portion357, instead of the first damper side spline359, is provided at the centripetal side end of the driven plate35.

The first binding portion357is connected to a second binding portion537of a second front cover plate53of a second cover plate51of the second damper50, which will be described below, and transmits a driven side rotational force of the first damper30to a driving side of the second damper50.

According to the second embodiment, the baffle plate37, which serves as the shield member and is illustrated inFIG.9, is attached to the driven body portion353. The baffle plate37may have a shape corresponding to a shape of a region of the driven plate35to which the baffle plate37is attached. The baffle plate37does not need to have the rigidity for transmitting the rotational force, and the baffle plate37only needs to have the rigidity that may guide the flow of oil.

The baffle plate37may be tightly attached and fixed to the radial inner surface of the inclined section of the driven body portion353, i.e., the front surface of the driven plate35. The driven plate35covers the first stopper accommodation portion355without entering a region of a trajectory along which the first stopper319moves in the first stopper accommodation portion355.

The baffle plate37includes a baffle body portion371configured to adjoin the front surface of the driven body portion353while covering the first stopper accommodation portion355provided on the driven body portion353, and a third binding portion373configured to fix the baffle body portion371to the driven plate35.

The baffle body portion371may cover a portion corresponding to the inclined section of the driven body portion353.

The third binding portion373may be disposed radially inside the baffle body portion371and have a shape corresponding to the first binding portion357of the driven plate35.

The third binding portion373may have a shape corresponding to the first binding portion357and the second binding portion537. For example, the first binding portion357, the second binding portion537, and the third binding portion373may have through-holes provided at positions corresponding to one another, and the first binding portion357, the second binding portion537, and the third binding portion373may be fastened altogether by means of common fastening means such as rivets. Then, the baffle plate37may be coupled together during a process of coupling the driven plate35and the second cover plate51, which needs to be performed anyway, without adding a process of separately fixing the baffle plate to the driven plate35.

The baffle plate37does not need to have the rigidity for transmitting the rotational force of the engine to the rotor hub90. The transmission oil, which serves to cool and lubricate the wet damper, only needs to move along the inclined section of the driven body portion353and be guided to flow to the first hysteresis device40and the first damper spring33without being discharged through the first stopper accommodation portion355. Therefore, the baffle plate37may be manufactured by using a much thinner material than the material of the driven plate35, which may reduce the weight.

Meanwhile, as described above with reference to the first embodiment, the oil needs to be supplied to the second damper50connected in series to the first damper30, as in the second embodiment. Further, in a design step, the amount of oil to be supplied to the first damper30and the second damper50may be appropriately distributed.

In the second embodiment, because the first stopper accommodation portion355is shielded by the baffle plate37, the oil, which is supplied to the radial inner space of the inclined section of the driven body portion353, is supplied to the first hysteresis device40and the first damper spring33without being discharged through the first stopper accommodation portion355.

Therefore, in the second embodiment, fluid passageways358,375, and538are provided to allow a part of the oil, which is supplied to the first damper, to move toward the second damper, such that a part of the oil, which is supplied to the radial inner space of the inclined section of the driven body portion353, is also supplied to a second hysteresis device and a second damper spring57.

In order to accurately design and control a flow path of the fluid, the fluid passageways may be provided at portions where the driven plate35, the second cover plate51, and the baffle plate37are in contact with one another. The fluid passageway may include a first fluid passageway358provided on the driven plate35, a second fluid passageway538provided on the second cover plate51, and a third fluid passageway375provided on the baffle plate37.

The first fluid passageway358may be formed on the first binding portion357of the driven plate35, the second fluid passageway538may be formed on the second binding portion537of the second front cover plate53, and the third fluid passageway375may be formed on the third binding portion373of the baffle plate37. Further, the third fluid passageway375, the first fluid passageway358, and the second fluid passageway538may constitute a single fluid passageway extending substantially in the axial direction.

Therefore, the amount of oil to be supplied to the first damper and the second damper may be designed by adjusting the sizes of the fluid passageways and the number of fluid passageways.

The second damper50includes the second cover plate51provided at the driving side, a driven hub59provided at the driven side, and the second damper spring57interposed between the driving side and the driven side.

The second cover plate51includes the second front cover plate53provided at the front side and a second rear cover plate55provided at the rear side with the second damper spring57interposed therebetween. The second front cover plate53and the second rear cover plate55may be fastened to each other at a radial outer end and integrally moved.

A front side of the second damper spring57is supported by the second front cover plate53, and a rear side of the second damper spring57is supported by the second rear cover plate55. In addition, the second front cover plate53and the second rear cover plate55support the second damper spring57in the radial direction.

The second damper spring57may be provided as a plurality of second damper springs57disposed in the circumferential direction. The embodiment exemplarily provides a structure in which four second damper springs57are disposed at equal intervals in the circumferential direction.

The second damper springs57may include a second damper large-diameter spring571and a second damper small-diameter spring573that define concentricity.

The second damper spring57is disposed in an arc shape.

The second front cover plate53includes a second cover body portion535, the second binding portion537provided at a radial inner end of the second cover body portion535and bound to the first binding portion357, a second spring cover portion531configured to support a front side of the second damper spring57and accommodate a front half side of the second damper spring57to support the second damper spring57in the radial direction, and a third circumferential support portion533configured to support the second damper spring57in the circumferential direction.

The second rear cover plate55includes a third cover body portion555, a third spring cover portion551configured to support a rear side of the second damper spring57and accommodate a rear half side of the second damper spring57to support the second damper spring57together with the second spring cover portion531in the radial direction, and a fourth circumferential support portion553configured to support the second damper spring57together with the third circumferential support portion533in the circumferential direction.

The embodiment exemplarily provides four second spring cover portions531and four third spring cover portions551.

In addition, the embodiment exemplarily provides four third circumferential support portions533and four fourth circumferential support portions553.

The four third circumferential support portions533, which are provided between the four second spring cover portions531, and the four fourth circumferential support portions553, which are provided between the four third spring cover portions551, support two opposite ends of the four second damper springs57. That is, one third circumferential support portion533and one fourth circumferential support portion553, which face each other in the axial direction, support the ends of the two second damper springs57that face each other when the two second damper springs57are adjacent to each other in the circumferential direction.

The driven hub59includes a hub body portion593, a second neck portion591extending radially outward from the hub body portion593, and a second damper side spline595provided at a centripetal side end of the driven body portion353.

The second neck portion591may be disposed between the third circumferential support portion533of the second front cover plate53and the fourth circumferential support portion553of the second rear cover plate55in the axial direction.

A circumferential width of the third circumferential support portion533and a circumferential width of the fourth circumferential support portion553may correspond to each other. Further, a circumferential width of the second neck portion591may be slightly smaller than a circumferential width of each of the third and fourth circumferential support portions533and553. Therefore, the second damper50may have a free angle.

Then, a sum of a free angle of the first damper30and a free angle of the second damper50may define a free angle of the torsional damper.

The damper side spline595is provided on an inner peripheral surface of the hub body portion593. Further, the damper side spline595engages with the engine clutch side spline71provided on the outer peripheral surface of the inner spline hub70connected to the engine clutch80so that a rotation thereof is restricted. Therefore, the rotation of the second damper50and the rotation of the engine clutch80are restricted in the rotation direction, and the second damper50and the engine clutch80are allowed to relatively slide in the axial direction.

When the rotational force of the engine is transmitted to the first cover plate31through the rotor shaft21and the rotor sleeve23, the first damper spring33, which is supported by the first cover plate31, presses the first neck portion351in the rotation direction and transmits the rotational force to the driven plate35. In this case, the first damper spring33absorbs a non-uniform rotational force of the engine, uniformizes the rotational force to some extent, and then transmits the rotational force to the driven plate35.

Further, the rotational force transmitted to the driven plate35is transmitted to the second cover plate51, and the second damper spring57is supported by the second cover plate51presses the second neck portion591in the rotation direction and transmits the rotational force to the driven hub59. In this case, the second damper spring57also absorbs and uniformizes a non-uniform output and then transmits the output to the driven hub59.

Then, the output of the engine is uniformized and transmitted to the rotor hub90through the engine clutch80.

In this case, a damping force of the second damper50may be designed to be higher than a damping force of the first damper30. Therefore, the low non-uniformity of the output may be mainly covered by the first damper, and the non-uniform output, which exceeds the damping force of the first damper, is covered by the second damper.

According to the second embodiment, free angles are imparted to both the first damper30and the second damper50. Then, when the rotational force of the engine is transmitted to the torsional damper, the free angle of the first damper30may be consumed first, and then the free angle of the second damper50may be consumed, such that the rotational force of the engine may be transmitted to the rotor hub90.

When the free angle, which the torsional damper needs to have, is uniformly distributed to the first damper30and the second damper50, as described above, maximum circumferential widths of the first neck portion351and the second neck portion591may be ensured.

Although not illustrated, like the first hysteresis device40installed on the first damper30, the second hysteresis device, which provides second hysteresis torque, may also be installed on the second damper50. Similar to the first hysteresis device, the second hysteresis device may also include a second front friction washer disposed between the second cover body portion535of the second front cover plate53and the hub body portion593of the driven hub59in the axial direction, a second rear friction washer disposed between the hub body portion593and the third cover body portion555of the second rear cover plate55in the axial direction, and a second elastic washer disposed between the hub body portion593and the second rear friction washer63in the axial direction. Then, the second elastic washer is disposed between the driven hub59and the second rear friction washer63in a state in which a preload is applied, such that the second hysteresis torque may be intuitively determined by the preload of the second elastic washer.

When the hysteresis torque is provided to both the two dampers connected in series as described above, the effect of reducing noise may be further improved, and in particular, the effect of reducing noise may be further improved when the engine idles. In this case, when the second hysteresis torque is higher than the first hysteresis torque, the resonance of both the first damper30and the second damper50is suppressed by hysteresis torque in the idling state of the engine, thereby suppressing noise.

In this case, both the first elastic washer45and the second elastic washer are disposed rearward of the driven plate35and the driven hub59. Therefore, because both the first elastic washer45and the second elastic washer press the driven plate and the driven hub forward, the elastic forces of the two elastic washers may be fully applied to the dampers without affecting each other.

With reference toFIG.1, the driven plate35is disposed at a foremost side with respect to the first cover plate31within an allowable range by the first elastic washer45. Therefore, the second cover plate51bound to the driven plate35is also disposed to be closest to the first cover plate31. Further, the driven hub59is disposed at a foremost side with respect to the second cover plate51within an allowable range by the second elastic washer. That is, the first elastic washer45and the second elastic washer dispose the components of the first and second dampers30and50at the foremost side within the allowable range.

Meanwhile, the engine clutch80may be pressed forward by the piston plate, and the driven hub59connected to the engine clutch80may receive a forward axial force even though the spline connection is made. However, because the first damper30and the second damper50has been already moved and disposed at the foremost side by the friction washers within the allowable range by the elastic washers as described above, the axial force is never transmitted to the elastic washers. Therefore, the torsional damper installed in the hybrid drive module of the second embodiment consistently applies a designed preload to the driven plate35and the driven hub59.

This means that the designed hysteresis torque does not change even under varying operating conditions. That is, according to the embodiment, the elastic washers, which provide hysteresis torque to the first damper30and the second damper50, may provide intended hysteresis torque by applying elastic force to the first damper30and the second damper50in response to a designed preload regardless of whether the engine clutch80operates.

When the hysteresis torque is applied to both the first damper30and the second damper50connected in series as in the embodiment, it is possible to improve the effect of reducing noise of the engine. In addition, when the second hysteresis torque, which is applied to the second damper50disposed to be farther from the engine in the drive system, is set to be equal to or higher than the first hysteresis torque applied to the first damper30disposed to be closer to the engine in the drive system, the hysteresis torque, which corresponds to an amplitude of an idling output of the engine, is applied to both the two dampers connected in series in accordance with the designed intention, such that the effect of reducing noise may be more assuredly exhibited.

While the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to the drawings and the embodiments disclosed in the present specification, and it is apparent that the present invention may be variously changed by those skilled in the art without departing from the technical spirit of the present invention. Further, even though the operational effects of the configurations of the present invention have not been explicitly disclosed and described in the description of the embodiment of the present invention, the effects, which can be expected by the corresponding configurations, should, of course, be acceptable.