Abstract: A method of transmitting torque through a flexible coupling includes driving a first rotatable member with a second rotatable member, applying an axial force component to the a flexible coupling connecting the first rotatable member and the second rotatable member by changing an axial offset between the first rotatable member and the second rotatable member interconnected by the flexible coupling, reducing one or more of the axial force component and cyclic equivalent stress born by a flexible diaphragm body of the flexible coupling by axially shifting the first end of the flexible diaphragm body relative to one of the interconnected rotatable members, and affixing a splined member to a second end of the flexible coupling, wherein the flexible diaphragm body has an inner diameter that is greater than an inner diameter of the splined member.

Abstract: A transmission device to divide torque between gears. The device comprising a coaxial motion input member and transmission members and comprising shafts having gears at an axial end. Flanges which project radially outwards from the shafts, at the opposite axial end with respect to the gears, are axially facing and arranged abutting against each other, and are fixed to the motion input member to divide the torque transmitted by the motion input member between the flanges. The second shaft being axially hollow. The first shaft comprising a first intermediate portion having an outside diameter smaller than the inside diameter of the second shaft and housed at least with radial clearance in the second shaft. The flanges comprise respective portions configured to deform under the action of forces acting between the motion input member and the gears to enable a fluctuation of the shafts with respect to an axis.

Abstract: A constant velocity joint including an outer race having inner and outer surfaces, the inner surface including a plurality of outer ball tracks. The constant velocity joint also includes an inner race having a plurality of inner ball tracks which correspond to the outer ball tracks, a ball cage disposed between the outer race and the inner race, a plurality of balls arranged within the ball cage and contacting the outer ball tracks and the inner ball tracks. A damping assembly is connected to the outer race.

Abstract: A flexible hub connection is disclosed for joining a first rotatable shaft with a second rotatable shaft so that torque can be transmitted between the shafts through the connection. The connection comprises a first flexible means having a first flex plane, a second flexible means having a second flex plane and, an intermediate member. The first flexible means is connected between the first rotatable shaft and the intermediate member, while the second flexible means is connected between the intermediate member and the second rotatable shaft. The first flex plane and second flex plane being substantially coplanar.

Abstract: A contoured disc coupling includes a plurality of fastening locations, wherein each fastening location has a body portion and an aperture running through the body portion, and a plurality of webs extending between adjacent fastening locations, wherein each web has a contoured shape.

Abstract: A variable cam timing apparatus (10) and method of assembly for transmitting rotational torque between a driving rotary member (15b) and a driven rotary member (15a). The flexible coupling (14) can include an axis of rotation coinciding with, and an outer peripheral edge (14a) extending at least partially around, or completely surrounding, a common rotational axis of the driving rotary member (15b) and the driven rotary member (15a). The flexible coupling (14) including a flexible body (14b) having a plurality of apertures (14c, 14d) formed therein at angularly spaced positions relative to one another for connection therethrough with respect to the driving and the driven rotary members (15b, 15a) permitting adjustment for perpendicularity and axial misalignment, while maintaining a torsionally stiff coupling between the driving and driven rotary members (15b, 15a).

Abstract: A connecting joint for connecting two shafts comprises a drive seat and an output seat, wherein the drive seat and the output seat are connected by a connecting means with one another, which may be provided in an angular way. Therein, the connecting means comprises an element which is at least partially flexible. One or multiple, in particular two, such connecting joints may be used in a connecting shaft for transmitting a rotation from a drive shaft to an output shaft, in particular in a connecting shaft of a drum for a drum set.

Abstract: A drive plate that has a ring gear capable of meshing with a gear of a motor, and that transmits power from the engine to an element to which the power is to be transmitted. The drive plate includes a plate member that is fixed to a crankshaft of the engine. A ring gear member is formed as an annular member having the ring gear in its outer periphery. A plurality of fastening portions are each fastened to the plate member on an inner peripheral side with respect to the ring gear. A plurality of extended weld portions each extend from the inner peripheral side with respect to the ring gear to a side of the element, each having a free end that is welded to an outer periphery of a constituent member of the element to which the power is to be transmitted.

Abstract: A flexplate coupling is disclosed. The flexpate coupling may be used as part of a transmission. The flexplate coupling comprises a flywheel, a damper assembly including a hub portion, and a flexplate. The flexplate includes a hub fastened to the hub portion of the damper assembly and a peripheral portion fastened to the flywheel.

Abstract: A drive plate for a torque converter, including: an annular shaped inner portion including an inner periphery for the drive plate and a plurality of openings for receiving fasteners for connection to a front cover of the torque converter; a plurality of outer portions along an outer periphery for the drive plate; and a respective drive tab for each outer portion. The respective drive tab includes: a top surface disposed outward from said each outer portion in an axial direction and substantially orthogonal to an axis of rotation for the drive plate; an opening in the top surface for receiving a fastener for connecting the drive plate to a flex plate; and first and second surfaces extending from the top surface and substantially parallel to an axis of rotation for the drive plate.

Abstract: A generator assembly (6) includes a crankshaft (10), an accessory pulley drive shaft (36) operatively coupled to the crankshaft (10), and a flexible drive coupling member (40) operatively coupling the accessory pulley drive shaft (36) and the crank shaft (10). The flexible drive coupling member (40) includes a plurality of flex drive rings (64-66) that are configured to transmit torque from the crankshaft (10) to the accessory pulley drive shaft (36) with substantially no torsional deflection while allowing the accessory pulley drive shaft (36) to deflect radially under radial load and deflect axially under axial load in order to accommodate misalignment of the accessory pulley drive shaft (36).

Abstract: A carrier plate and related method for an automatic transmission is provided, whereby the carrier plate has a ring gear (1) connected to a driving plate (2) by means of welding and has at least one thickening plate (4, 5) connected to the driving plate (2) by means of welding. Preferably the ring gear (1) is connected to the driving plate (2) means of beam welding using auxiliary material.

Abstract: A drive plate for a torque converter, including: an annular shaped inner portion including an inner periphery for the drive plate and a plurality of openings for receiving fasteners for connection to a front cover of the torque converter; a plurality of outer portions along an outer periphery for the drive plate; and a respective drive tab for each outer portion. The respective drive tab includes: a top surface disposed outward from said each outer portion in an axial direction and substantially orthogonal to an axis of rotation for the drive plate; an opening in the top surface for receiving a fastener for connecting the drive plate to a flex plate; and first and second surfaces extending from the top surface and substantially parallel to an axis of rotation for the drive plate.

Abstract: Two embodiments of an improved connection between an engine output shaft and a transmission input shaft reduce or eliminate axial shaft loading and spin losses. In a first embodiment, the transmission input shaft includes an annular flange which is received within a slightly larger annulus or a plurality of axially extending tabs from the engine flex plate. After the transmission and engine are assembled, a plurality of fasteners are installed in radial openings in the flex plate annulus or tabs and extend into threaded openings in the annular flange. Since the output and input shafts are connected after the engine and transmission are assembled there is essentially no deflection of the flex plate, no axial loads on the shafts and no spin losses. In a second embodiment, a plurality of axially oriented threaded fasteners extend through openings in the flex plate and are received within nuts in a transmission drive plate. The nuts include eccentric flanges and are retained in the drive plate by snap rings.

Abstract: A coupling assembly for transmitting torque between a first body and a second body is disclosed herein. The coupling assembly includes a diaphragm plate extending radially between a radially inner periphery fixed for rotation with the first body. The diaphragm plate extends to a radially outer periphery and is operable to elastically deform in response to changes in the axial positions of the first and second bodies relative to one another. The coupling assembly also includes a socket assembly engaged with the radially outer periphery of the first diaphragm plate for concurrent axial movement in response to changes in the axial positions of the first and second bodies relative to one another. The socket assembly is also operable to transmit torque between the second body and the diaphragm plate. The socket assembly includes a radially-accommodating structure operable to at least partially move in response to changes in an outer profile of the second body.

Abstract: A torsionally rigid flexible shaft coupling, in particular, fully-steel shaft coupling, for transmitting torques between shafts, in particular shafts with axes which are offset relative to one another, having one or two plate packs (5) which are placed on flange sleeves (6) and on the latter, are clamped by means of a ring (4) against an end-side flange (65b) of the flange sleeve (6), wherein the plate packs are clamped in an alternating fashion in the peripheral direction to the sleeves (8) or second hubs (9), which face one another, by means of screws (7) which extend through the flange sleeves (6) and have nuts (2).

Abstract: A universal double-jointed coupling for railway vehicles with two joint levels comprises two coupling joints which are interconnected via a shaft that is surrounded by a hollow pinion shaft in order to transmit torque by means of said hollow pinion shaft. One joint level is assigned to a coupling joint encompassing a crowned gear that has angular and axial compensation capability while the other joint level is associated with a torsion-proof, flexible coupling joint.

Abstract: A flexible disk for connecting a transmission shaft to rotate with a mechanical part, the flexible disk being suitable for forming rotary motion about an axis of rotation and including in succession going from its center towards its periphery an empty central zone, a circular base, a transition zone having an outer face and an inner face, and then a peripheral collar.

Abstract: A transmission joint for angularly connecting a first and a second member, and having a coupling member interposed functionally between the first and second member and extending about an axis; the coupling member has: a first portion connectable angularly to the first member, a second portion connectable angularly to the second member and located radially outwards of the first portion, and an intermediate portion interposed radially between the first and second portion and elongated in a direction crosswise to the axis; the intermediate portion of the coupling member has, from the first portion to the second portion, a first portion decreasing in thickness crosswise to the direction, and a second portion of constant thickness.

Abstract: A drive system for a motor vehicle comprises a drive unit with a drive shaft and a torque-transmitting assembly, which is to be connected on the drive side to the drive shaft for rotation in common around an axis of rotation (A) and which is to be connected on the takeoff side to a gearbox. The drive-side connection is accomplished by means of an axial plug-in connection arrangement, and the torque-transmitting assembly is supported in at least one axial direction on the gearbox.

Abstract: The present invention relates to a clutch device (2) having at least one output hub (46), which can be rotationally locked to a transmission input shaft (50), an input hub (16), in which an assembly opening (54) is provided, so that a fastener (58) for axially fixing the output hub (46) to the transmission input shaft (50) can be introduced by way of the assembly opening (54), and a flex plate (74), on which a hub part (56) is provided, which can be rotationally locked to the input hub (16). According to the invention the hub part (56) can be connected to the input hub (16) in such a way that the assembly opening (54) is closed by the hub part (56).

Abstract: A decoupler assembly for a motor vehicle driveline comprising a decoupler, an input driveably connected to a transmission output shaft and including a first connection that secures the input to the decoupler, and an output driveably connected to a final drive axle then to wheels of the vehicle, including a second connection that secures the output to the decoupler, and a support that provides bending continuity between the input and the output, the support permitting rotation of the input about an axis relative to the output, the decoupler, the first connection and the second connection providing resistance to such rotation.

Abstract: A drivetrain for use with a power unit is disclosed. The drivetrain may have a crankshaft, a flywheel having spline teeth, and a flexible plate connecting the crankshaft to the flywheel. The drivetrain may also have a driven member having spline teeth configured to mate with the spline teeth of the flywheel, and a limiter associated with at least one of the flywheel and the driven member. The limiter may be configured to limit a maximum axial movement and a maximum radial movement between the flywheel and the driven member.

Abstract: The present invention relates to a carrier plate for an automatic transmission, whereby the carrier plate has a ring gear (1) connected to a driving plate (2) by means of welding and has at least one thickening plate (4, 5) connected to the driving plate (2) by means of welding. The present invention furthermore relates to a method for the production of such a carrier plate. With a view to economical production of solid and dimensionally accurate carrier plates, the present invention proposes that the ring gear (1) be connected to the driving plate (2) on the one hand and that the driving plate (2) be connected to the at least one thickening plate (4, 5) on the other hand by means of beam welding, preferably laser beam welding (FIG. 1).

Abstract: A diaphragm coupling having first and second diaphragm plates that are joined together around their outer edges. Each diaphragm plate has a central, axially-extending hub. The hub of the first plate supports within it a pin member having an outwardly projecting shoulder at each end adapted to engage an internal shoulder on the hub of the first plate at one end and an internal shoulder on the hub of the second plate at the other end so as to limit axial separation of the two hubs—from one another.

Abstract: A torque transmission device having a torque converter which is accommodated in the drivetrain of a motor vehicle, for transmitting torque between a drive unit and a transmission, has a converter housing that is rotationally mounted about an axis of rotation and is nonrotatably connected to the drive unit. The torsionally fixed connection between the drive unit and the converter housing includes a tubular connecting element that is located coaxially to the axis of rotation of the converter housing.

Abstract: A drive plate for a coupling device, especially a hydrodynamic torque converter, for connecting a housing of the coupling device to a drive element includes a drive plate body designed as a formed metal part, where a bearing projection extending more-or-less in the direction parallel to an axis of rotation is formed on the radially inner area of the drive plate body.

Abstract: In the invention, a coupling device for interconnecting two substantially constant velocity systems or shafts (40, 41) includes two parallel plates (11, 12) united in their central region and forming a single part (10).

Abstract: A shaft coupling has an input element adapted to be rotationally driven about an axis, an output element rotatable about the axis adjacent and limitedly relative to the input element, and an intermediate element rotatable about the axis adjacent and limitedly relative to both the input element and the output element. A first coupling assembly with progressive resistance to torque is fixed between one of the input and output elements and the intermediate element. A second coupling assembly with linear resistance to torque is fixed between the other of the input and output elements and the intermediate element such that torque is transmitted between the input and output elements through the coupling elements in series with each other in a single stage.

Abstract: The invention provides a compressor for use as a secondary compressor for an ethylene polymerization tubular reactor comprising a motor and at least two compressor frames, at least one of the compressor frames being coupled to the motor by means of a contoured diaphragm flexible coupling.

Abstract: A disc pack coupling for transmitting torque between two shafts approximately aligned on a shaft axis a hub assembly including an end adapter adjacent to a hub flange. A center member is fixed to the end adapter and is encircled by a disc pack. The disc pack resiliently couples the end adapter and the hub flange.

Abstract: A flexplate (10) that is configured for attachment to an engine crankshaft and a transmission, includes a generally circular plate (12) having a mounting portion (20) disposed generally centrally on the plate (12). An outer rim portion (16) is disposed peripherally around the plate (12), and a transition portion (18) is disposed between the mounting portion (20) and the outer rim portion (16). At least one counterweight (50) is disposed on the transition portion (18) of the plate (12). The flexplate (12) has only one axis of symmetry (B-B) that lies along a plane defined by the plate (12).

Abstract: A power transmission device that can have deformation in processing suppressed. A spiral gear as a rotation member includes a disk section extending radially outwards from a boss section. The disk section includes a through hole in slit form through laser processing.

Abstract: A torsional vibration damper includes a primary side having a pair of axially spaced cover disk elements which are fixed to each other, and a central disk element axially between the cover disk elements, wherein each disk element has a like plurality of circumferentially arranged openings, and each opening has a pair of circumferential support areas. A like plurality of damping element units are arranged in respective sets of openings, and are supported against the circumferential support areas. A radial support surface supports each damping element unit in a radially outward direction, each radial support surface extending without curvature in the axial direction.

Abstract: The coupling (10) has a flexible disk (12), that is arranged between two rotary bodies (34, 36). Linings (16) are embedded in the flexible disk (12) at regular intervals about a central axis (C), parallel to the same. Connection bodies (18), that are each surrounded by one of the linings (16) and can be displaced in a limited manner in relation thereto, can be fixed alternately to each of the rotary bodies (36, 38). The linings (16) respectively form a ball-and-socket joint (20) with the associated connection bodies (18). The flexible disk (12) contains two pairs of such diametrically opposed ball-and-socket joints (20). The two linings (16) of each pair of ball-and-socket joints (20) are interconnected by means of a rigid cross-member (26). The coupling (10) is able to transmit rotary movements between two rotary bodies (34, 36) in a reliable, accurate and essentially loss-free manner, when the axes of the rotary bodies are inclined in relation to each other at an angle of at least 15 degrees.

Abstract: A piston plate stop for a torque converter including: a flexible connection element with a first end and a second end, the first end arranged to connect to a piston plate for the torque converter, the second end arranged to rotationally connect to a cover for the torque converter and a stop disposed on the flexible connection element. The stop is arranged to restrict axial movement of the piston plate. In some aspects, the flexible connection element is arranged to rotationally connect the cover and the piston plate. A torque converter including a piston plate; a cover; and at least one flexible connection element rotationally connecting the piston plate and the cover. The flexible connection element has a tab that is positioned to limit axial displacement of the piston plate away from the cover.

Abstract: The invention concerns a device for coupling a rotor of a rotating electrical machine with the gearbox primary shaft of a motor vehicle heat engine. The device is characterized in that the hub (7) of the rotor (6) is coupled with the primary shaft (8) by a mating part (25) comprising an externally toothed crown (26) meshing in the hub (7) and a central sleeve (27) coupled with the primary shaft (8) through a splined connection (28) and in that ends (29) and (30) of the toothed crown (26) and of the central sleeve (27) of the part (25) are centered respectively in the hub (7) and on the primary shaft (8) in sliding arrangement. The invention is applicable in the automotive industry.

Abstract: In a flywheel 2, a central part of a thin plate portion 3 having a flywheel mass provided on an outer peripheral side of the plate portion is joined to an end surface of a crankshaft 1 through a plurality of bolts 7 disposed annularly at intervals. Within a contact zone of a substantially polygon defined by linking each center of the bolts 7 with straight lines excluding the bearing surfaces of the bolts 7, the plate portion 3 has a non-contacting part S2 in a followed fashion set not to contact with the end surface of the crankshaft 1, and the area of the non-contacting part S2 is set to be 40% to 75% of the whole area of the contact zone.

Abstract: A coupling has an inner ring centered on an axis, an outer ring surrounding and generally coaxial with the inner ring, and an intermediate ring generally coaxial with and between the inner ring and outer ring. A pair of mainly angularly extending, flexible, and parallel inner links have inner ends attached at respective locations to an outer periphery of the inner ring and outer ends attached at respective locations to an inner periphery of the intermediate ring, and a pair of mainly angularly extending, flexible, and parallel outer links have inner ends attached at respective locations to an outer periphery of the intermediate ring and outer ends attached at respective locations to an inner periphery of the outer ring. The outer links extend transversely of the inner links, and the rings and links are unitarily formed with one another.

Abstract: An adjustable coupler for in-line coupling of a motor drive shaft of an agricultural system with the square drive shaft of a gearbox, wherein the coupler has an adjustable clamping hub for securing around differing sizes of square drive shafts while maintaining coaxial alignment between the coupler, the square drive shaft and the motor drive shaft. The coupler is adjustable to fit different size square drive shafts, yet maintains symmetry about the center axis of the coupler, thereby reducing off-balance forces that could result in wear points and early fatigue. Contact surfaces between the coupler components are minimized to reduce the likelihood that contaminants can become entrapped between the components. The coupler is comprised of a round hub and a square hub, each attached to the opposite sides of a shock absorbing puck. The square hub is symmetrical about the axis of the puck and is formed of two axially sliding, opposing L-shaped brackets configured to clamp around the square end of a drive shaft.

Abstract: A drive arrangement for a motor vehicle includes a drive shaft, a coupling device, and a coupling arrangement. The drive shaft is connectable with the coupling device for transmission of force solely via the coupling arrangement. The coupling arrangement has a first toothing arrangement connectable with the drive shaft so that the first toothing arrangement is fixed with respect to rotation relative to the drive shaft and a second toothing arrangement connectable with the coupling device so that the second toothing arrangement is fixed with respect to rotation relative to coupling device. The first toothing arrangement and second toothing arrangement engage when the drive shaft and coupling device are coupled together for transmission of force.

Abstract: The invention concerns a driving disc for transmitting the torque from one drive unit to a hydrodynamic converter (2). The driving disc (5) has one leg (51) extending in radial direction and fastened on the output shaft (1) of the drive unit and one leg (52) extending in axial direction and fastened on supporting devices (4) of a housing (3) of the hydrodynamic converter (2). By recesses (10) spaced apart from each other in peripheral direction of the driving disc (5), there are formed in the leg (52) extending in axial direction bracket arrangements which serve to fasten the leg (52) extending in axial direction on supporting device (4) situated in the housing (3). The bracket arrangements are each formed by tongue-shaped brackets (11, 12; 11′, 12′) which seen in peripheral direction extend successively from both sides of the recess (10). The end areas of the brackets (11, 12; 11′, 12′) are each fastened on one supporting device (4).

Abstract: A flexible coupling for coupling together a pair of axially misaligned shafts of which the respective ends of the shafts retainably fit within a hub within the interior of which the longitudinal axes of the shafts meet at a common point. A plurality of arms extend radially outwardly along the hub and a portion of the hub adjacent each and extend toward each other into the interior of the hub into contact with a bearing contained within the hub of the common point, whereby ends of each respective shaft and hub retaining portion are movable relative to one another.

Abstract: A coupling has an inner ring centered on an axis, an outer ring surrounding and generally coaxial with the inner ring, and an intermediate ring generally coaxial with and between the inner ring and outer ring. A pair of mainly angularly extending, flexible, and parallel inner links have inner ends attached at respective locations to an outer periphery of the inner ring and outer ends attached at respective locations to an inner periphery of the intermediate ring, and a pair of mainly angularly extending, flexible, and parallel outer links have inner ends attached at respective locations to an outer periphery of the intermediate ring and outer ends attached at respective locations to an inner periphery of the outer ring. The outer links extend transversely of the inner links, and the rings and links are unitarily formed with one another.

Abstract: A brake assembly includes a flex disk brake secured to a brake device of a press clutch-brake combination. A plurality of axially flexible finger elements extends from a peripheral side of the flex disk in a bent or arcuate configuration. The finger elements extend at least in part in a circumferential direction of the flex disk generally opposite to a direction of rotation of the press crankshaft. Each finger element is secured at one end to the stationary press crown. During brake activation, the axial flexibility of each finger element accommodates axial displacement of the attached brake device as the brake device undergoes actuated movement into its braking position. The flex brake disk provides a torquing rigidity that renders it rotationally stationary.

Abstract: A drive arrangement for a motor vehicle includes a drive shaft, a coupling device, and a coupling arrangement. The drive shaft is connectable with the coupling device for transmission of force solely via the coupling arrangement. The coupling arrangement has a first toothing arrangement connectable with the drive shaft so that the first toothing arrangement is fixed with respect to rotation relative to the drive shaft and a second toothing arrangement connectable with the coupling device so that the second toothing arrangement is fixed with respect to rotation relative to coupling device. The first toothing arrangement and second toothing arrangement engage when the drive shaft and coupling device are coupled together for transmission of force.

Abstract: A drive arrangement for a motor vehicle includes a drive shaft, a coupling device, and a coupling arrangement. The drive shaft is connectable with the coupling device for transmission of force solely via the coupling arrangement. The coupling arrangement has a first toothing arrangement connectable with the drive shaft so that the first toothing arrangement is fixed with respect to rotation relative to the drive shaft and a second toothing arrangement connectable with the coupling device so that the second toothing arrangement is fixed with respect to rotation relative to coupling device. The first toothing arrangement and second toothing arrangement engage when the drive shaft and coupling device are coupled together for transmission of force.

Abstract: The rotary housing of a hydrokinetic torque converter, which can be utilized in the power train of a motor vehicle—for example, in conjunction with a continuously variable transmission—contains a torque monitoring device which is installed in such a way that it does not take up any, or any appreciable, additional space, especially in the axial direction of the housing. The torque monitoring device can serve to transmit torque between the lockup clutch and the output element of the torque converter. Additional features reside in the provision, configuration and manner of mounting of an auxiliary mass, and in the provision of a member for centering the piston of the lockup clutch in the housing as well as a member for centering the housing on the output element of a prime mover.

Abstract: An annular disk for flexible shaft couplings is described, whose two coupling halves each exhibiting a connection flange are connected to each other via a packet of such annular disks in a torsionally rigid manner, but in such a way as to enable their axial and angular movement. The annular disk has four attachment holes uniformly distributed on a shared hole circle, wherein the section is tapered between two adjacent attachment holes. The annular disk according to the invention satisfies the following size ratios: Dt/D1=10 to 12, D2/Dt=1.1 to 1.2, Dt/B1=9 to 16, and B2/Dt=0.88 to 0.93, wherein Dt is the diameter of the hole circle, D1 is the diameter of the respective attachment hole, D2 is the largest outside diameter of the annular disk, B1 is the width of the narrowest part of the annular disk section between two consecutive attachment holes, and B2 is the width of the annular disk outer contour.

Abstract: A crankshaft assembly for an internal combustion engine includes a crankshaft, an elastic member fixed to the crankshaft, and a flywheel fixed to the elastic member such that the flywheel is supported in an elastic relationship with the crankshaft. The elastic member has a rigidity in its rotating direction large enough to effectively transmit a driving power to a transmission through a clutch. On the other hand, the elastic member has a rigidity in an axial direction of the crankshaft small enough to shift a resonance frequency of a bending vibration out of a target frequency band of a forced vibration, while ensuring to prevent a failure of disengagement of the clutch.