Abstract: A fabricated crankshaft for single and multi-throw crankshafts utilizes roller bearings for achieving energy savings and reducing the size of parts and components with the single throw crankshaft using two throws interconnected by one main bearing pin and one drive end unit connected to each throw and the multi-throw crankshaft including at least two pair of throws, one crank pin interconnecting each pair of throws, a main bearing pin interconnecting both pairs of throws, and a pair of drive end units, with the drive end units and the crank pins, the connecting pins, and main bearing pins being secured to the throws by configurations that include keys and keyways, splines, and left and right hand thread arrangements so that the fabricated crankshaft is adaptable to any number of cylinders required.

Abstract: In accordance with certain embodiments, a modular crankshaft features a connection system between modules that features opposed female receptacles. A pin having opposed beveled ends and hydraulic passages with it is inserted into the opposed receptacles. A pair of seals is disposed on the beveled ends and straddles a hydraulic fluid outlet. The crankshaft wall that defines each receptacle is designed to flex in response to applied hydraulic pressure between the seals on the tapered pin portion. A notch at the base of the receptacle in the crankshaft reduces stress concentration and enables the wall defining the crankshaft receptacle to come back when hydraulic pressure through the pin is removed. The opposed crankshaft receptacles are flanged to allow them to be pulled together over the pin. An interference fit results around the pin after the flanges are mated and the hydraulic pressure is removed.

Abstract: A crankshaft has a non-homogenous structure is unitarily formed in a powder metallurgy process with at least two different metallic constituents providing dissimilar characteristics at discrete locations of the structure.

Abstract: The invention relates to an assembled crankshaft composed of a plurality of crank cheeks which can be connected at one side to a main bearing journal and at the other side to a connecting rod bearing journal. The invention is based on the object of providing a crankshaft which is assembled from a plurality of individual parts, which is simple and quick to mount, which is characterized by a weight reduction and with which satisfactory lubrication of the bearing regions can be provided. According to the invention, the crank cheeks are provided at both sides with a ring-shaped groove for receiving the tubular main bearing journal and connecting rod bearing journal. In addition, the crank cheeks are provided with openings for a sleeve, which sleeves are in each case arranged within the main bearing journal and connecting rod bearing journal and are connected in a form-fitting and/or force-fitting manner to the crank cheeks.

Abstract: A crankshaft, in particular to be developed as part of an internal combustion engine of a motor vehicle, with at least one main bearing for connecting the crankshaft with an engine block, wherein the main bearing is developed at least partly, so that the axial border areas of the main bearing are convexly opposite the mid-section of the main bearing configured between the axial border areas, and/or with at least one large end bearing to connect the crankshaft with a connecting rod, wherein the large end bearing is at least partially developed so that the axial border areas of the large end bearings are convexly opposite the mid-section of the large end bearing, configured between the axial border areas. Through that it is possible to increase the stiffness of the crankshaft, without the need to alter the fittings on the main bearing and/or on the large end bearing.

Abstract: A crankshaft having a crankpin, a crank journal, and a crank arm for linking the crankpin and the crank journal, includes a pin fillet portion located between the crankpin and the crank arm, and a journal fillet portion located between the crank journal and the crank arm. At least one of the crankpin and the crank journal has a diameter of no less than about 20 mm and no more than about 40 mm. At least one of the pin fillet portion and the journal fillet portion contains a quench-hardened layer having a thickness of no less than about 1 mm and no more than about 2 mm in the vicinity of a surface thereof. The crankpin and the crank journal substantially do not contain any quench-hardened layer having a thickness exceeding about 2 mm in the vicinity of a surface thereof.

Abstract: Disclosed herein is a hollow-type crankshaft for use in an internal combustion engine and a reciprocal type air compressor, which includes a crankshaft web for connecting a crankshaft journal to a crankshaft pin, the crankshaft comprising: a reinforcing groove portion 4 formed on the outer peripheral surfaces of the crankshaft pin 1 and the crankshaft journal 2, and formed with a slope portion 41 inclined inwardly from both lateral walls of thereof, and a reinforcing member 40 made of metal different from the basic material, the reinforcing member being inserted into, melt-jointed and cast in the reinforcing groove portion 4.

Abstract: A method is provided for cold forming center web or webless tapered piston pins in one forming sequence. The method eliminates secondary operations such as but not limited to machining, annealing, coating and secondary forming. The method includes the steps of cutting a metal rod into a substantially cylindrical slug piece, die extruding the slug piece to form a first cavity in the slug piece, optionally die extruding the slug piece to form a second cavity in the slug piece, piercing the slug piece to form the slug piece into a hollow cylindrical piece, die extruding the hollow cylindrical piece at either end to form a hollow cylindrical piece having a taper on an internal surface of the hollow cylindrical piece at either end.

Abstract: The invention concerns a compressor crankshaft, particularly a refrigerant compressor crankshaft (1) and a method for manufacturing such a crankshaft, with a shaft element (2), a crank pin (9) located eccentrically to the shaft element and a transition element (7) between the shaft element (2) and the crank pin (9). The purpose of the invention is to keep the manufacturing costs low. For this purpose, it is ensured that along its circumference the transition element (7) has at least one first reference point (20) and one second reference point (21a, 21b), with which the transition element (7) can be positioned in a holding fixture (25) of a working machine.

Abstract: A crankshaft (1) includes a first to a sixth crank pin (41–46), a first to a fourth main journal (21–24) and a first to a ninth crank arm (61–69). At least the first, the second, the eighth and the ninth crank arms (61, 62, 68, 69) have respective integral counterweights (61?, 62?, 68?, 69?) for balancing the crankshaft (1). In order to reduce bending stress on the areas where the second and the eighth crank arms (62, 68) are connected to the respective pairs of adjacent crank pins (41–42, 45–46), the axial dimensions of the first and the ninth crank arms (61, 69) are reduced, being substantially the same as those of the adjacent crank arms (62, 68) in order that the axial length of the two end spans of the crankshaft is the same as that of the intermediate span. In order to balance the crankshaft (1), two additional counterweights (71, 72) are arranged outwardly of the end journals (21, 24) and their axial dimensions are comparable to those of the end crank arms (61, 69).

Abstract: This invention relates to a mechanism and method for enhancing the performance of both two stroke and four stroke cycle reciprocating piston internal combustion engines, reciprocating piston pumps and compressors by generating an Epitrochoidal path of travel for the lower end of the connecting rod. The piston, attached to the upper end of the connecting rod, will be made to dwell at the lower part of its travel, enhancing the output of the engine, pump or compressor through better utilization of the available cylinder pressure.

Abstract: In an assembly type crankshaft, a press-in plug member for assembly of its crank pin is set to be shorter than the width of the crank web, allowing the press-in force of the plug member to be reduced and the weight of the crank pin into which the plug member is pressed to be reduced. The crank pin of the crankshaft and the crank web, that have been fabricated as separate members, are made integral with each other by pressing the crank pin into a pin hole formed in the crank web. As a result, the crankshaft is assembled. Thus, after the assembly, the plug member whose length is shorter than the width of the crank web is pressed in, a firm crankshaft can be obtained. Further, since the plug member employed has a cross-sectional shape that is elliptical or oval-shaped, the above-described press-in can be performed more firmly.

Abstract: A cranshaft including a continuous first or main journal and at least one eccentric second journal is disclosed. A corresponding connecting structure includes a pair of channels for receiving the journals. When the connecting structure is driven in a reciprocating fashion, it causes the crankshaft to rotate, or vice versa. A separate connecting structure may be associated with the continuous main journal and each eccentric journal forming part of the crankshaft. The connecting structure may include a single piston, or a pair of pistons in an opposed relationship, each corresponding to a different cylinder in an internal combustion engine. Alternatively, the connecting structure may include a tool, such as a saw blade, and cause it to reciprocate upon rotation of the crankshaft.

Abstract: A multi-piece crankshaft having a shaft with two ends and in which the shaft is adapted to rotate about its shaft axis and a crankpin with at least one indentation. The shaft and crankpin are placed within a mold having a first mold cavity corresponding in shape to the desired counterweight and the other end of the shaft is positioned within a second mold cavity corresponding in shape to a flywheel taper support for the crankshaft. The counterweight and flywheel taper support are then both formed by simultaneously casting a liquid material, such as zinc, into both the first and second mold cavities.

Abstract: A workpiece, in particular a crankshaft, the surface of which in a region (4, 4′) to be hardened has a plurality of mutually spaced, hardened, preferably laser-hardened portions, characterised in that the extent (d) and/or the spacing (s) of the hardened, preferably substantially punctiform portions vary (varies) over the region (4, 4′) to be hardened.

Abstract: A cranshaft including a continuous first or main journal and at least one eccentric second journal is disclosed. A corresponding connecting structure includes a pair of channels for receiving the journals. When the connecting structure is driven in a reciprocating fashion, it causes the crankshaft to rotate, or vice versa. A separate connecting structure may be associated with the continuous main journal and each eccentric journal forming part of the crankshaft. The connecting structure may include a single piston, or a pair of pistons in an opposed relationship, each corresponding to a different cylinder in an internal combustion engine. Alternatively, the connecting structure may include a tool, such as a saw blade, and cause it to reciprocate upon rotation of the crankshaft.

Abstract: A crankshaft assembly for an internal combustion engine having a one-piece elongated shaft adapted to rotate about a longitudinal axis. The shaft includes a radially offset portion between the ends of the shaft, and this radially offset portion is spaced axially inwardly from each end of the shaft. An elongated connecting rod having a one-piece annular bearing support at one end is secured to the shaft so that the annular bearing support is positioned around the shaft offset portion. A first counterweight is secured to the shaft adjacent one end of the shaft offset portion while a second counterweight is secured to the shaft adjacent the other end of the shaft offset portion. In an alternate embodiment, the crankshaft, crankpin and one counterweight are formed as a casting. A one-piece connecting rod is then slid onto the crankpin and a second counterweight is molded to the crankshaft on the side of the crankpin opposite from the cast counterweight.

Abstract: A camshaft assembly (11) having a tubular shaft (12) and a plurality of cams (14) which are each provided with a through-aperture and which are slid on to the tubular shaft (12) and secured thereto at distances from one another, wherein the tubular shaft (12), between the cams (14), includes inwardly hot-formed lateral indentations (22). A method and device for producing the camshaft assembly are also provided.

Abstract: A crankshaft being integrated with stemmed, inertia-forced lobes that increase engine and motor efficiency, in which a respective lobe extends and branches out to a single traversal side of crankshaft integration, and thus being right-angular to its integration. Essentially, the lobe is a structurally-curved limb having respective curvature about the traversal axis of crankshaft rotation. Hence, the ensuing inertia from the lobes actually rotate. in the same direction and in parallel with the crankshaft, and thus retaining at least 99% of lobe force, to significantly increase engine and motor output power. By contrast, conventional lobes retain only 50% of inertial force. Furthermore, if the lobes' outer extended, weighted portions are “loaded” with very heavy material, such as lead, then the power output becomes proportionally greater.

Abstract: A crankpin 1 of a crankshaft rotatably supports a big end of a connecting rod 4 through a sliding bearing 5 fitted therein. The sectional profile of the crankpin 1 takes the form of a polygon whose profile is made of plural arcs of curvature. When the crankpin 1 rotates relative to the bearing 5, the wedge effect is generated to decrease the squeeze loss, a kind of the power loss. And, the oil film thickness between the crankpin 1 and the bearing 5 is secured to prevent the shear loss, another kind of the power loss, from increasing, whereby the power loss can be decreased in total.

Abstract: In an assembly type crankshaft, a press-in plug member for assembly of its crank pin is set to be shorter than the width of the crank web, allowing the press-in force of the plug member to be reduced and the weight of the crank pin into which the plug member is pressed to be reduced. The crank pin of the crankshaft and the crank web, that have been fabricated as separate members, are made integral with each other by pressing the crank pin into a pin hole formed in the crank web. As a result, the crankshaft is assembled. Thus, after the assembly, the plug member whose length is shorter than the width of the crank web is pressed in, a firm crankshaft can be obtained. Further, since the plug member employed has a cross-sectional shape that is elliptical or oval-shaped, the above-described press-in can be performed more firmly.

Abstract: A torque transmitting device having a rotating shaft and a gear connected to the shaft. The gear transmits the torque between the rotating shaft and the gear. A splined portion and a centering inner circumferential surface portion formed in the inner periphery of the gear are engaged with the splined portion and the centering outer circumferential surface portion formed on the outer periphery of the rotating shaft. This arrangement minimizes noise due to gear runout, and reduces wear in the gear.

Abstract: A wrist pin is provided comprising a generally cylindrical body having a longitudinal axis. The body is fabricated of at least two metallic parts joined to one another at a weld joint. In joining the two parts to one another, a pair of laterally spaced support ribs are defined and an internal chamber is further defined between the support ribs.

Abstract: The invention relates to a crank shaft having a guide groove allowing the movement of a crank pin so as to adjust the reciprocating distance of a piston according to the rotating direction. The crank shaft comprises a rotation shaft for inducing the rotating movement; and a crank arm connected to the rotation shaft at the center and having at one side a guide groove provided horizontal in the radial direction for allowing free movement of a crank pin and elastic means provided within the guide groove to enhance the performance of sucking and compressing fluid.

Abstract: A crankshaft assembly for use with a connecting rod having a one-piece crankpin bearing support. The crankshaft assembly includes a first one-piece crankshaft portion having a first counterweight, a first end of a main axle extending outwardly from one end of the first counterweight, and a crankpin extending outwardly from the other end of the first counterweight. Similarly, a second one-piece crankshaft portion includes a second counterweight, a second end of the main axle extending outwardly from one end of the second counterweight. The second one-piece crankshaft portion also includes a crankpin receiving hole formed in the second counterweight. The one-piece crankpin bearing support on the connecting rod is positioned over the crankpin and, thereafter, the first and second crankshaft portions are secured together by press fitting the crankpin on the first crankshaft portion into the receiving hole on the second crankshaft portion. A method of manufacturing the crankshaft assembly is also disclosed.

Abstract: A multi-piece crankshaft having a shaft with two ends, an axis and adapted to rotate about its axis. A crankpin also has two ends and an axis parallel to but spaced radially outwardly from the shaft axis. The crankpin optionally has at least one indentation. A plate has two spaced openings such that one end of the shaft is positioned in one of the plate openings while the other end of the shaft is positioned in the other plate opening. At least one counterweight extends between said one end of the shaft and said one end of the crankpin, and this counterweight is formed by casting a liquid metal around the ends of the shaft and the crankpin as well as around the plate. The liquid metal fills the at least one indentation and, upon hardening, locks the counterweight to the crankpin and shaft and encases the plate.

Abstract: The subject matter of the invention is a hollow shaft with power transmission members such as cams of a camshaft, crown gears of a gear shaft or journals of a crankshaft disposed one behind the other in an axial direction, the power transmission members being configured to be at least partially hollow, said power transmission members being configured integral with the hollow shaft and the material being hardenable at least in the region of the power transmission members.

Abstract: The present invention relates to a device (1) for the rotating slaving of a crankshaft (2) that is held at its two axial ends (3, 4) respectively between centers (5, 6) of a metal-removing machine tool and is equipped with a surface plate (7). Slaving is achieved by a slaving system (8) that is connected to the surface plate (7) or that can be connected thereto, extends parallel to the rotational axis (9) of the crankshaft (2) and is provided at its free end with a slaving body 913) attacking at a lifting journal (14) of the crankshaft (2).

Abstract: A positive lock for infinite adjustable stroke alignment mechanism for a mechanical press with an eccentric bushing disposed within a press connection member with a second eccentric member disposed within the eccentric bushing. A rotatable crankshaft is connected to the second eccentric member. A positive lock alignment mechanism is included for aligning the press connection member with the eccentric bushing to prevent rotation therebetween and permitting rotation of the second eccentric member with the eccentric bushing for infinite stroke adjustment whereby rotation of the crankshaft, when the mechanism is activated causes a press stroke adjustment.

Abstract: A crankpin 1 of a crankshaft rotatably supports a big end of a connecting rod 4 through a sliding bearing 5 fitted therein. The sectional profile of the crankpin 1 takes the form of a polygon whose profile is made of plural arcs of curvature. When the crankpin 1 rotates relative to the bearing 5, the wedge effect is generated to decrease the squeeze loss, a kind of the power loss. And, the oil film thickness between the crankpin 1 and the bearing 5 is secured to prevent the shear loss, another kind of the power loss, from increasing, whereby the power loss can be decreased in total.

Abstract: A multiple crank drive for working machines, in particular for diaphragm pumps, with a crankshaft, which is disposed in a housing and which exhibits at lest two bearings, can be driven by a drive, in particular a gear, and in turn drives by a crank drive, one of several piston rods of the working machines. The drive is designed in such a manner that the crankshaft is suspended in the housing.

Abstract: A method for mounting an axially split sleeve provided with an axial slot on a shaft so that a tapering surface on the sleeve cooperates with a tapering bore of a machine member. A flange is axially connected to the sleeve and supports a number of spaced apart tightening devices that are to be urged against the machine member for mutually displacing the machine member and the sleeve to increase the grip between the shaft, the sleeve and the machine member. The method involves positioning the sleeve around the shaft with the annular flange positioned with its tightening devices against the machine member, tightening a first one of the tightening devices which is located at a position diametrically opposite the slot in the sleeve, and thereafter tightening further ones of the tightening devices one by one.

Abstract: For a crankshaft of a motor with two outputs, which are braced against each other on a common shaft section by means of an essentially axial directed bracing force, measures are suggested, which deflect the axially directed bracing force into a bracing force with a radial component, that acts on at least one output.

Abstract: An airless spray pump has a drive train is comprised of a motor having an output gear thereon which drives a combination gear assembly comprised of two gears mounted on a shaft which in turn drives a crank assembly which is comprised of a one-piece eccentric end gear molded together and mounted on a shaft which is supported at both ends to prevent cantilevering and attendant stresses. The crank assembly is offset from the vertical axis of the displacement pump in order to reduce side-loading thereon. A connecting rod is mounted via a pin directly to the top of the displacement rod of the reciprocating pump. Retainer pin clippingly retains the pin in the connecting rod and enables the pin to be removed for servicing without the use of tools other than potentially a screwdriver or other generic tool.

Abstract: A multi-piece crankshaft is disclosed having a shaft with two ends and in which the shaft is adapted to rotate about its shaft axis. A crankpin also has two ends and an axis parallel to but spaced radially outwardly from the shaft axis. The crankpin optionally has at least one indentation. A plate has two spaced openings such that one end of the shaft is positioned in one of the plate openings while one end of the crankpin is placed in the other plate opening. The shaft also includes at least one indentation at a position adjacent its other end. The shaft and crankpin are placed within a mold so that the plate is positioned within a first mold cavity corresponding in shape to the desired counterweight. Simultaneously, the indentation adjacent the other end of the shaft is positioned within a second mold cavity corresponding in shape to a flywheel taper support for the crankshaft.

Abstract: For a crankshaft of a motor with two outputs, which are braced against each other on a common shaft section by means of an essentially axial directed bracing force, measures are suggested, which deflect the axially directed bracing force into a bracing force with a radial component, that acts on at least one output.

Abstract: For a crankshaft of a motor with two outputs, which are braced against each other on a common shaft section by means of an essentially axial directed bracing force, measures are suggested, which deflect the axially directed bracing force into a bracing force with a radial component, that acts on at least one output.

Abstract: An improved counterweight for a crankshaft having a main body which is adapted to rotate about a predetermined axis. The main body includes a major lobe on one side of the axis and a diametrically opposed minor lobe. Two recessed surfaces extend on opposite sides of a diametric line bisecting the major and minor lobes so that the recessed surface forms a portion of the outer periphery of the crankshaft. A pair of inserts is provided and each insert has a surface complementary to one of the recessed surfaces on the main body. Each insert is inserted into the main body to form a generally cylindrical counterweight.

Abstract: A method of driving part ejector pins at a high cycle rate by a reversible servo motor rotating a crank unidirectionally to advance a pin mounting structure from a retracted position to an advanced eject position, and back to the retracted position, and reversing the motor to repeat the cycle with only a single motor reversal.

Abstract: The invention relates to a crankshaft for a reciprocating internal combustion engine, with the crankshaft having a crankpin (11) with an eccentric sleeve (10), through the rotation of which relative to the crankpin the effective stroke of a crankshaft can be modified. Sleeve (10) can be locked in two positions separated by 180° by means of two locking elements (7, 14). The locking elements are arranged in the crankshaft and are supplied with a hydraulic fluid via feed lines (2, 4), which likewise extend in the crankshaft. A feed line (3) for a fluid can furthermore be provided, this being passed to the inner surface of the sleeve (10) in such a way that a torque about the crankpin (11) can be exerted on said sleeve.

Abstract: A variable stroke crankshaft assembly includes a drive shaft surrounded by a sleeve. A crankshaft is disposed inside the drive shaft with the longitudinal axis of the crankshaft offset from the longitudinal axis of the drive shaft. A gear projecting outwardly from the crankshaft through a window in a drive shaft engages angled gear teeth on the inner surface of the sleeve allowing sliding movement of the sleeve relative to the drive shaft to rotate the crankshaft. A crankpin is attached to the crankshaft but offset from the rotational axis of the crankshaft. Rotational movement of the crankshaft with respect to the drive shaft thus pivots the crankpin with respect to the rotational axis of the drive shaft creating a crank stroke that may be varied by sliding the sleeve back and forth.

Abstract: A multi-piece crankshaft having a main shaft with two ends adapted to rotate about its axis. A crankpin also has two ends and an axis parallel to but radially spaced from the axis of the main shaft. At least one counterweight extends between one end of the shaft and one end of the crankpin and this counterweight is formed by casting a liquid metal around the ends of the main shaft and crankpin in a molding chamber. In a modification of the crankshaft, a hollow crankpin is disposed within the mold such that each end of the crankpin is positioned within a mold cavity corresponding to a counterweight. Upon casting the liquid metal in the mold cavities forming the counterweights, the molten metal flows inwardly from both ends of the crankpin and joins together to form a continuous metal connection between the counterweights.

Abstract: A welded crankshaft having a number of individual elements and cavities formed in the region of the main bearing journals and crank journals. The individual elements are configured so that oil passages in the overlap region between the main bearing journals and crank journals run substantially in the axial direction, and transition via radial orifices directly into the journal surface. The cavities of the main bearing journals and crank journals can be made very large, so that the weight of the crankshaft is kept light. In addition, because of the simple geometry of the oil passages, the crankshaft can be manufactured in modular fashion from the individual elements.

Abstract: A rotational component, such as a crankshaft for an internal combustion engine or the like, has fractional portions of the circumferential journal surfaces selectively hardened, as by induction hardening for example. The selectively hardened portions of the journal surfaces may include radially facing bearing surfaces, journal fillets, and other critical zones such as oil hole breakout zones and thrust face fillets. Selective hardening reduces component distortion and processing costs while providing the desired durability enhancement.

Abstract: A ferrite core partly covered with ceramics members is loaded into an oil hole defined in a pin, and high-frequency induction hardening is effected on the pin while the ferrite core is being held in position by copper wires. At the same time, a magnetic field is generated from the ferrite core to produce a high-frequency induction hardened layer having progressively spreading skirt regions extending from a position in the vicinity of a center in an axial direction of the oil hole toward openings in ends of the oil hole.

Abstract: A parting line strategy for a crankshaft (100) includes providing a parting line that has a plurality of portions that extend across a plurality of cheeks (104, 106, 108) and pins (120, 126, 136, 142, 152, 158). Further, the parting line has a portion (126, 142, 158) that extends generally diagonally across a face (168) of each of the plurality of cheeks (104, 106, 108) to assist in removing flash from the crankshaft (108).

Abstract: A multiple crank drive for working machines, in particular for diaphragm pumps, with a crankshaft, which is disposed in a housing and which exhibits at lest two bearings, can be driven by a drive, in particular a gear, and in turn drives by a crank drive, one of several piston rods of the working machines. The drive is designed in such a manner that the crankshaft is suspended in the housing.

Abstract: A crankshaft assembly for an internal combustion engine having a one-piece elongated shaft adapted to rotate about a longitudinal axis. The shaft includes a radially offset portion between the ends of the shaft, and this radially offset portion is spaced axially inwardly from each end of the shaft. An elongated connecting rod having a one-piece annular bearing support at one end is secured to the shaft so that the annular bearing support is positioned around the shaft offset portion. A first counterweight is secured to the shaft adjacent one end of the shaft offset portion while a second counterweight is secured to the shaft adjacent the other end of the shaft offset portion. In an alternate embodiment, the crankshaft, crankpin and one counterweight are formed as a casting. A one-piece connecting rod is then slid onto the crankpin and a second counterweight is molded to the crankshaft on the side of the crankpin opposite from the cast counterweight.

Abstract: An all terrain vehicle comprises an engine located under a hingably mounted seat, the seat providing ready access to the engine for maintenance and repair. The engine is placed in the vehicle such that the crankshaft is parallel to the line of travel and the crankshaft is in line with the longitudinal axis of the vehicle. The engine has two output shafts. The front output shaft extends forwardly of the engine to a front differential on the front axle and the rear output shaft extends rearwardly to a rear differential on the rear axle. The front and rear output shafts are in communication with one another by gears which enables different ratios of revolution between-the front and rear axle. The all terrain vehicle is also equipped with a parking gear which locks the two output shafts and prevents rotation with respect to the transmission housing.

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.