Abstract: An engine power section for piston engines, particularly V-engines, having a power unit block made of an iron material arranged in a casing of light metal. In order to achieve a stiff weight-reducing power unit block, a flange plate used for limiting the crank space as well as for the connection with the casing is arranged offset relative to a cylinder from its lower end toward its upper end with its front side surface center of gravity at a distance on this side of the bearing center plane of a crankshaft bearing, which corresponds at least to a largest possible distance of the surface center of gravity of a reinforcing profile of a bearing frame on the other side of the bearing center plane. The crankshaft bearings are connected with the flange plate by way of struts.

Abstract: A lightweight high-strength cylinder block that is configured so as to provide an enlargement at one end thereof that defines a bell housing. The enlargement is provided with cavities, however, so as to lighten the weight of the cylinder block without substantially reducing its strength. At least one of these cavities can provide for communication of oil return and/or crankcase ventilating gases and also may function as a thermostat housing. An embodiment wherein the cylinder block extends below the crank shaft axis to form the upper portion of the crankcase is also disclosed.

Abstract: A cylinder block for a multi-cylinder internal combustion engine with a multi-bearing crankshaft and a water jacket surrounding the cylinders. The outer wall of the water jacket extends downwards approximately into a parting plane of the crankshaft bearings. A base frame rests against and is connected to a contact surface formed by a circumferential free edge of the water jacket outer wall. The crankshaft bearings are arranged on the base frame and detachable bearing caps are arranged and fastened by screws on the side of the base frame facing the cylinders.

Abstract: An internal combustion engine for a vehicle includes a crankshaft, a piston movable through a cycle, a piston rod connecting the piston and the crankshaft, an oil pan spaced from the crankshaft, and an oil source providing pressurized oil. An inventive windage tray is positioned between the crankshaft and the oil pan. The windage tray includes a passage having an inlet port receiving the pressurized oil and a first outlet port directing a first stream of the pressurized oil at the piston. In a preferred embodiment of the present invention, the passage further includes a second outlet port directing a second stream of pressurized oil at the piston. The first outlet port is positioned to direct the first stream of pressurized oil upon the piston unobstructed by the piston rod during a first portion of the piston cycle. The second outlet port is positioned to direct the second stream of pressurized oil upon the piston unobstructed by the piston rod during the remaining portion of the piston cycle.

Abstract: The invention is directed to a two-stroke engine for a portable handheld work apparatus such as a motor-driven chain saw. The engine includes a cylinder housing and a crankshaft journalled in shaft bearings. The cylinder housing is closed by a crankcase cover. Half shells are formed in the cylinder housing and the crankcase cover to accommodate the shaft bearings. Overflow channels are formed in the wall of the cylinder and lead from the crankcase to the combustion chamber. The overflow channels are open at their ends facing toward the crankcase cover and interrupt the support surface of the half shells formed in the cylinder housing. An adequate support of a small crankshaft bearing is ensured for an arrangement of several overflow channels. This is achieved in that the half shells are configured with a significantly larger diameter than the outer diameter of the shaft bearing and a support shell is seated in the free space between the half shell and the shaft bearing.

Abstract: A crank chamber structure for an engine which is designed to reduce vibratory noise, to achieve a reduction in weight and cost, and to improve lubricating performance. The crank chamber structure is positioned between a block-side skirt section and a case-side skirt section respectively provided in a cylinder block and a lower case. The skirt sections are curved outwardly to permit the crank chamber to enclose peripheral loci of connecting rods, and further to permit the crank chamber to be formed by a curvilinear surface whose radius is smaller at successively higher positions above the crankshaft axis, thereby providing a substantially egg-like cross-sectional shape. An opening is provided in the lower case by the case-side skirt section being collapsed to taper toward an oil pan-mating surface of the lower case so as to communicate with the oil pan.

Abstract: In an engine for a vehicle including a bearing cap integral type oil pan which has a plurality of bearing cap sections integrally provided thereon and which is integrally coupled to a cylinder block, connecting bolts are screwed into the bearing cap sections from the cylinder block to integrally couple the cylinder block and the oil pan to each other. An oil pan chamber, which is an as-cast bore made by drawing a die in an axial direction of a crankshaft, is defined to extend continuously in the axial direction of the crankshaft between the bearing cap sections and a bottom wall of the oil pan. Thus, the oil pan can be produced simply, at a low cost, by a casting process and moreover, it is possible to reduce the weight and size of the oil pan and increase the rigidity of the oil pan.

Abstract: In a crankcase for a piston machine having a bearing support structure for a crankshaft main bearing with a bearing base part integrally formed with the bearing support structure and a bearing cover mounted onto the bearing base part by bearing bolts extending into bolt mounting columns, the bearing support structure includes a transverse wall which extends between the crankcase walls, the bearing support base and the bearing base part and includes a rib structure of an increased wall thickness formed between the bearing base part and the bearing support base and having a recess in the area between the end of a mounting bolt bore in the bolt mounting column and the bearing support base providing for a force flux path which istributes the force flux evenly over the length of the threaded mounting bolt bore area.

Abstract: An engine assembly is disclosed which includes a cylinder block having cylinders, pistons disposed in the cylinders, and connecting rods connecting the pistons to a crankshaft. The crankshaft rotates to move the pistons reciprocally in the cylinders thereby inducing volumetric changes within the engine and, particularly between axially adjacent pistons. A crankcase disposed below the cylinder block has axial sidewalls extending therefrom to define a crankcase volume in which the crankshaft is disposed for rotation. Crankcase bulkheads extend laterally to connect the axial walls and define cylinder bays therebetween. Each of the crankcase bulkheads includes a crankshaft journal support and a surface configured to rotatably receive a complementary bearing cap for support of the crankshaft therebetween.

Abstract: A pulley assembly for a driven shaft is disclosed. The pulley assembly includes a pulley to which a turning force is transferred from a driving unit; a sleeve fixedly mounted to a casing of the driven unit through which the driven shaft passes with a clearance between an outer periphery of the driven shaft and an inner periphery of the sleeve; a bearing structure for bearing the pulley rotatably about an axis of the driven shaft, the bearing structure being disposed between the pulley and the sleeve; and a torque transferring structure for transferring the turning force transferred to the pulley to the driven shaft, the torque transferring structure being interposed between the pulley and the driven shaft.

Abstract: An engine having a lower block made of an aluminum-based material and having a bearing cap mounted therein in a cast-in manner abutting against front and rear sidewalls of a cylinder block of the engine and coupled to the cylinder block by a bolt, and a pump body is coupled to a lower surface of the lower block by bolts. The pump body also serves as a balancer shaft supporting member, and a journal portion of a balancer shaft is supported on the balancer shaft supporting member. Thus, the rigidity of supporting of the balancer shaft on the balancer shaft supporting member can be enhanced without an increase in size of the balancer shaft supporting member of the engine.

Abstract: A piston engine which includes an engine block composed of a base material. The engine which block has a cylinder block with at least one cylinder formed therein, a piston located in the cylinder, and a crankshaft connected to the piston and being mounted on crankshaft bearings disposed in a crankcase of the engine block. The engine further includes a plurality of reinforcing components connected to the walls of the engine block. The reinforcing components are composed of a component material that is different from the base material and has a higher modulus of elasticity than the base material.

Abstract: In an engine block comprising a casting including side walls extending along a row of cylinders and front and rear walls extending between the side walls with top flanges for mounting a cylinderhead and bottom flanges for mounting an oil pan, the side walls have sections extending forwardly beyond the front wall to define therebetween a timing drive chamber.

Abstract: A flexible oil pan assembly of a flexible internal combustion engine has a plurality of spaced apart flexible baffles disposed between and connected to a first surface of first and second spaced apart side walls and a plurality of stiffening ribs connected to a second surface of the first and second side walls at preselected spaced locations. The combination of the baffles and stiffening ribs facilitates controlled deflection of the first and second side walls and reduces the potential for cracking of the first and second side walls.

Abstract: A tappet and camshaft carrier that includes expansion bars which directly interconnect adjacent bulkhead members to compensate for the differential rate of thermal expansion between the carrier and the base to which the carrier is fastened.

Abstract: A main bearing cap for an internal combustion engine has a longitudinally extending body defined in pan by parallel sides which terminate in first and second end portions. The bearing cap has a centrally located, semi-cylindrical bearing recess which cooperates with a corresponding recess in the engine crankcase to support journals of a crankshaft along a crankcase axis. The first and second end portions of the bearing cap include laterally outwardly extending flanged feet having end faces which mate with corresponding surfaces on the engine crankcase. The flanged feet operate against the engine crankcase to limit motion of the bearing cap body.

Abstract: An oil pan for a combustion engine includes two extrusions which are welded to one another so as to form an elongated chamber. The ends of the chamber are closed by covers. At least two partitions are disposed one above the other inside the chamber. The partitions extend transversely of the chamber and are carried by holders provided on the internal surfaces of the extrusions. Each of the partitions has an oil deflecting portion as well as two flat projections which protrude to opposite sides of the respective oil deflecting portion and serve to connect the partitions to the holders. The projections of each partition define a horizontal support plane for the respective partition while the oil deflecting portions define vertical surfaces for damping oil surges.

Abstract: An oil pan for an internal combustion engine includes an outer shell made of metal plate an includes on at least a bottom surface of the outer shell and inner pan separate from the outer shell. The bottom of the oil pan includes a deep portion and a shallow portion and a baffle plate is disposed over the inner pan. The inner pan settles on the inner surface of the outer shell amidst the oil contained in the oil pan, thereby forming a layer of oil between the outer shell and the inner pan. Thus, oil flow is not impeded and vibration of the oil pan is significantly reduced. In addition, wall portions of the inner pan are made to be deformable so as not to cause strong impact to other portions of the oil pan structure or to engine components.

Abstract: A structural baffle for reducing both crankshaft torsional vibration and oil aeration in an internal combustion engine. The baffle includes a baffle plate and a number of upright members. The baffle plate isolates the oil reservoir from the turbulence generated by the crankshaft, and includes openings allowing oil flowing from the engine to return to the oil reservoir. Preferably, the baffle plate includes a number of oil return towers which align with the oil return ports of the engine to channel oil to the reservoir. The upright members are mounted to the bearing caps both to bolster the bearing caps and to support the baffle plate beyond the throw of the crankshaft.

Abstract: An internal combustion engine includes a bearing cap (3) for positioning the crankshaft (40) within the cylinder block (1). Spacer sleeves (20), which are attached with the main bearing cap bolts (5), are provided with dowel pins (32) having free ends (33) extending therefrom. The free ends of the dowel pins are mated with pockets (34) formed on the inner surface of the reinforcement element. A hardenable material (38) is injected into the space formed between the dowel pins and the pockets so as to form a locked reinforcement element to each of the dowel pins.

Abstract: An internal combustion engine with variable compression which includes a cylinder receiving section which is tiltably mounted to a crankcase section (4) of the engine, and a crankshaft (12) which is mounted in the crankcase section via crankshaft bearings (90) arranged in the lower region of the crankcase section (4). The crankshaft bearings incorporate bearing caps (102) which constitute continuous stiffening transverse connecting elements between the lower later parts (103,106) of the crankcase section. These transversely connecting bearing caps rest at their outer ends (108, 110) against internal surface areas in the lower lateral parts (104, 106) of the crankcase section on both sides of the engine. The bearing caps (12) are secured in the crankcase section (40) not only by means of vertical crankshaft bearing screws (112, 114) but also by means of screwed joints (166, 118, 120) which connect the lower lateral parts to the outer ends (108, 110) of the bearing caps.

Abstract: A cylinder head for an internal combustion engine, having an iron lower base part with inlet and exhaust ports and controlling valves therefor and an aluminum upper support for the camshaft and valve tappets. The upper part includes an open lattice work formed by spaced interconnected segments and curved sections extending between spaced bulkheads integral therewith that can be readily fastened to the base part to provide overhead support for the valve tappets. The lattice work has special expansion and contraction joints that connect into the bulkheads which mount the camshaft so that different rates of thermal expansion and contraction occurring between the lattice work and lower base part will cause deflection of the expansion joint and will not adversely effect the operation of the camshaft or the tappets carried by the bulkheads and lattice work.

Abstract: The present invention provides a low noise level internal combustion engine including a cylinder block without a skirt portion, a supporting member for supporting a journal portion of the crankshaft, the supporting member being fixed to a lower end portion of the cylinder block, a shroud for suppressing an explosion sound in a cylinder and a bearing sound to be radiated out of the engine, the shroud being integrally formed with a cylinder head fixed to an upper side of the cylinder block whereby the shroud is spaced from the cylinder block.

Abstract: A high horsepower internal combustion engine has an elongated block that is flexible during engine operation and an oil pan having sidewalls and is connectable to the block and flexible therewith. The oil pan has a plurality of baffles that are positioned within the oil pan, connected thereto at spaced apart locations and each have a flexible portion between the connecting location and the body of the baffle.

Abstract: A cylinder block for reducing engine vibrations and noises comprises a plurality of cylinder bores, a flared skirt portion integrally molded with a lower part of the cylinder block, and a curved ladder frame portion integrally molded with a lower part of said skirt portion. The unitary molded skirt and ladder frame structure is formed in a generally gutter configuration and defines a chamber adapted to accommodate therein a bearing block mounted to a lower portion of the cylinder block. Further, the unitary molded skirt and ladder frame structure is isolated from the bearing block.

Abstract: A skirt section of the cylinder block is shortened to the height of the rotational center of the crank shaft. To the bottom end of the skirt section is the lower cylinder block whose bottom end is coupled to the oil pan. The inner space of the lower cylinder block section is divided by plural partition walls extending transversely between the side walls of the lower cylinder block section. A bearing cap supporting the crank shaft has a boss section projecting transversely and a threaded hole is formed in the boss section. Further, the bottom end of the bearing cap has a threaded hole having an opening facing bottom. The lower cylinder block section is further provided at its side wall with a hole through which the side portion of the bearing cap is connected to the side wall of the lower cylinder block section. The bottom end of the bearing cap is connected to the side wall of the lower cylinder block section.

Abstract: A cylinder block including an upper block, a crankshaft and a lower block, has a plurality of bearing caps secured to the upper block so as to support the crankshaft for rotation. A generally rectangularly-shaped lower block casing is provided with a first reinforcing rib, located below each bearing cap and extending upright so as to connect opposite side walls of the casing, and a second reinforcing rib, extending from a fitting bracket. A transmission casing is fitted to the cylinder block through the fitting bracket. The second reinforcing rib terminates approximately below one of the bearing caps. The first reinforcing rib associated with the one of the bearing caps is separated from the bearing caps. The first reinforcing ribs are provided with structural stiffnesses such that a first reinforcing rib which is farther away from the one of the bearing caps than another first reinforcing rib has a lower structural stiffness than the other first reinforcing rib.

Abstract: The present invention discloses a structural oil pan for use with an internal combustion engine having a crankcase with short side walls of the type that generally do not extend below the center line of the crankcase. The oil pan has internal ribs which slidingly receive lower portions of the main bearing caps. The main bearing caps are fixed, relative to the oil pan with bolts passing through openings in the pan to threadingly engage corresponding openings in the bearing caps. Such an oil pan design allow the crankcase side walls, the crankshaft main bearing caps and the oil pan side walls to be structurally joined to resist vibration and noise generation. Weight savings are recognized by the oil pan of the present invention as the need for an engine block having extended side walls and increased weight is supplanted by a light weight, structurally rigid oil pan.

Abstract: A V-shaped internal combustion engine in which the driving chain for an oil pump is arranged by using a free space which is formed between a crank journal portion and a sprocket for a timing chain, so that there is no need to extend the crank shaft and to place the oil pump at a position in front of the internal combustion engine. The entire length of the internal combustion engine is reduced and its size is minimized. The oil pump is attached to a skirt portion which is provided at the lower portion of the cylinder block and to a bearing beam which supports the engine crank shaft.

Abstract: A cylinder head assembly for ues in an internal combustion engine is provided, which includes a valve drive mechanism having a plurality of pairs of a rocker-arm shaft and a rocker arm, the rocker shafts being rotatably supported by a rocker shaft cap incooperation with journals of a cylinder head, and the rocker arms being swingable together with the rocker-arm shafts. The rocker shaft cap has a plurality of cap portions for supporting the rocker-arm shafts, disposed in parallel with each other in one direction, and corresponding in number to journal portions of the cylinder head, and pairs of beam portions respectively supporting both sides of the plurality of cap portions, and extending in parallel with each other in the one direction, wherein the cap portions and pairs of beam portions are formed to be integral with each other thereby to constitute a ladder frame structure. Oil paths are formed in the cap portions and beam portions.

Abstract: An engine cylinder block includes lower and upper cylinder block portions which are fastened together by bearing cap fastening bolts and cylinder block fastening bolts. The engine cylinder block is provided with a baffle plate, for separating a crankcase from an oil pan. The baffle plate is fastened to the engine cylinder block by the cylinder block fastening bolts. Bearing cap fastening bolts are arranged in a row parallel to an axis of rotation of the crankshaft at each side of a row of bearing caps. The cylinder block fastening bolts, each of which is located between adjoining bearing caps, are arranged in a row parallel to the axis of rotation of the crankshaft on each side of the row of bearing caps.

Abstract: A V-type engine cylinder block includes a mounting pedestal, integrally formed with the block in a V-shaped space between two cylinder banks and interconnecting the cylinder banks. A top wall is secured to the mounting pedestal and extends over almost the entire length of the V-shaped space in a lengthwise direction of the cylinder block. A plurality of bosses are formed with internal threads for securing a bracket, for mounting the cylinder block onto a car body, to one end wall of the cylinder block by bolts. The mounting pedestal and bosses are interconnected by ribs integrally formed with the cylinder block.

Abstract: An improved engine block and crankshaft bearing assembly with an arrangement of the engine block and the bearing assembly that simplifies casting of the engine block, with the block having cylinders and a crankcase with opposed spaced support structures in the crankcase for mounting thin profile, forged steel upper bearing caps between adjacent cylinders with the upper bearing caps spanning the spaced support structures and coupling to conventional bearing caps for at least the main bearings of the crankshaft between the end bearings.

Abstract: A compact power unit for an internal combustion engine including a bearing arrangement for the crankshaft which includes a combined crankcase member and bearing cap that has integral bearing journals for the crankcase and which also forms at least in part the crankcase closure. An output shaft for powering a vehicle is also journaled by the cylinder block and crankcase member and is driven by an integral gear formed on one of the throws of the crankshaft. A balancing arrangement for accommodating this non balanced throw and for maintaining equal cylinder bore spacing is also employed.

Abstract: The invention relates to a bearing bridge connecting the main bearing seats of a reciprocating-piston combustion engine in the longitudinal direction of the crankshaft. To reduce the power loss caused by the oil flowing back into the crank case space striking the rotating drive parts, and the oil ageing rate, it is proposed to provide the bearing bridge between the main bearing seats with a shape which screens off the rotating drive parts of the combustion engine with respect to the crank case space.

Abstract: An engine unit includes a cylinder block of a short-skirt type which has a plurality of first partition walls and a plurality of crank journals formed on the partition walls and rotatably receiving the crankshaft. Bearing caps are fitted to the crank journals and rotatably hold the crankshaft in cooperation with the crank journals. A lower case is fixed to the cylinder block and covers the crankshaft. The lower case includes a pair of flanges abutting against the lower edges of the skirt portions, a semi-cylindrical bottom wall, and a plurality of second partition walls formed on the bottom wall to oppose the first partition walls. Each bearing cap is clamped between the first and second partition walls. The lower case is fixed to the cylinder block by means of first bolts screwed into the skirt portions through the flanges, and second bolts screwed into the crank journals through the second partition walls and bearing caps.

Abstract: An internal combustion engine having a reinforced cylinder block, a skirt portion integrally formed therewith at a lower portion thereof, a plurality of bearings received therein, a crank shaft journaled in the bearings, a plurality of bearing caps secured to the bearings, and front and rear covers formed at front and rear portions of the cylinder block, respectively, and having respective openings through which the crank shaft extends. In order to reinforce the cylinder block, a reinforcing member is secured to a lower surface of the skirt portion of the cylinder block and to a lower surface of the rear cover. At least two first bolts for fastening the reinforcing member to the lower surface of the rear cover are provided on opposite sides of the rear cover while at least two second bolts for fastening the reinforcing member to a bearing cap for a rearmost bearing of the bearings are placed within a pitch of the first bolts in a direction transversely of the cylinder block.

Abstract: A crankshaft supporting device for a multi-cylinder engine including a plurality of bulkheads provided in a cylinder block of the engine to be arranged along an axis of the crankshaft, disposed in a lower part of the cylinder block. A bearing cap member has a plurality of bearing cap portions each coupled with a lower end of one of the bulkheads so as to constitute a bearing portion for supporting the crankshaft in conjunction with the bulkhead, and a pair of beam portions extending along the axis of the crankshaft to interconnect therethrough two adjacent bearing cap portions. A reinforcement member has a side wall portion which is coupled with a skirt portion of the cylinder block, and a plurality of bolt seats are located underneath the beam portion of the bearing cap member. A plurality of ribs interconnect at least one of the bolt seats and at least one of the side wall portions. A plurality of bolts fasten the beam portions with the bolt seats.

Abstract: The invention relates to internal combustion engines and especially to two-stroke engines for portable handheld work tools such as motor-driven chain saws or the like. Material made of light metal alloys is used in two-stroke engines for portable handheld tools in order to save weight. Thus, the crankshaft bearing is made of steel while the bearing covers holding the bearing are made of a magnesium alloy. Heating causes the bearing cover to expand by an amount greater than the crankshaft bearing whereby the press fit of the crankshaft bearing can become endangered and, in an extreme case, a clearance can develop between the crankshaft bearing and the bearing cover. According to the invention, the press fit between the crankshaft bearing and the bearing cover is maintained by placing a plastic annular segment therebetween having a thermal expansion coefficient so selected that it compensates for the different thermal expansions of the bearing cover and the bearing.

Abstract: A positive crankcase ventilation system for a V-type internal combustion engine has elongated first and second cylinder banks provided with first and second rows of cylinders offset, respectively, in a lengthwise direction to each other, thereby forming a dead corner on one end of each cylinder bank. A series of reinforcing bulk heads for reinforcing a series of main bearings holding a crankshaft divide a crankcase into a series of crankcase chambers. Each crankcase chamber is provided with a bottom opening and vent holes formed in the bulk head. An air introduction passage is provided by the side of and at the middle of each row of cylinders in the cylinder block for introducing filtered air into and through the crankcase and oil return passages are formed in each dead corner.

Abstract: To increase the rigidity of camshaft bearing portions of the cylinder head on the camshaft driving side of an DOHC engine, an each member for symmetrically supporting two camshafts is formed integral with the cylinder head in such a way that the inner arcuate surface thereof extends to both inner side walls of the cylinder head.

Abstract: In a multi-cylinder internal-combustion engine, bearing shell and bearing cap of the bearings for the crankshaft are decoupled from the side walls of the cylinder block which form the crankcase. The bearing shells communicate with the cylinder block directly through column elements. The resilience of the column elements relieves the cylinder block of any transverse flexure by crankshaft forces and reduces the generation of noise.

Abstract: An arrangement for supporting a crankshaft in a multicylinder engien comprises a plurality of bulkheads provided in a cylinder block of the engine to be arranged at predetermined intervals along an axis of the crankshaft disposed in the cylinder block, a plurality of bearing caps each coupled with a lower end of one of the bulkheads by a cap bolt screwed into the bulkhead through a part of the bearing cap relatively close to the bulkhead so as to constitute a bearing portion for supporting the crankshaft in conjunction with the bulkhead, a beam structure extending along the axis of the crankshaft to interconnect therethrough adjacent two of the bearing caps, and a reinforcing structure coupled with the beam structure with a plurality of clamped spots generally arranged in the direction along which the crankshaft extends and also coupled with each of side skirt portions of the cylinder block with a plurality of clamped spots generally arranged in the direction along which the crankshaft extends.

Abstract: A cylinder block reinforcement construction for an engine includes a reinforcement member fixed to a skirt portion of a cylinder block of the half-skirt type and fastened to each of bearing caps bearing the crankshaft of the engine. The reinforcement member is formed in a platelike configuration and a substantially dishlike sectional shape and includes a bottom face portion, side face portions rising from both side ends of the bottom face portion, and flange portions provided at upper edges of the side face portions so as to be fastened to the skirt portion. The reinforcement member is provided, at positions corresponding to respective of the bearing caps and spaced in the axial direction of the crankshaft, with protuberant portions for attachment to respective of the bearing caps. The bottom face portion may be provided with bottom vent holes, each being provided between adjacent of the protuberant portions at a position corresponding to the respective cylinder.

Abstract: The oilpan of a low-noise crankcase is bolted to the downwardly extending ankcase sidewalls and has omega-shaped crosspieces extending transversely to the oilpan sidewalls and to the sidewalls of the crankcase, and the crosspieces are in alignment with the main bearing walls of the crankcase. The crosspieces form part of the oilpan and are connected to its sidewalls in such a manner that forces are propagated, the sidewalls being reinforced as compared to the bottom of the oilpan which is not reinforced. The oilpan is bolted to the crankcase by additional bolts located in pockets in the crosspieces on both sides of the cylinder axes, and are attached to the crankcase as far away from the outer walls thereof as possible.

Abstract: An internal combustion engine has a crankcase coupled to a lower end of a cylinder block, the crankcase including an upper case integrally formed with the cylinder block and a lower case fixed to the upper case. The upper and lower cases have a plurality of journal support walls projecting from inner wall surfaces thereof. An oil pan is fixed to the lower open end of the lower case. A crankshaft is rotatably sandwiched by the journal support walls. A breather chamber is mounted on one side of the crankcase and defined by recesses on confronting surfaces of the upper and lower cases, the breather chamber having one end communicating with the crank chamber and an opposite end communicating with an air intake system. At least one balancer shaft is rotatably supported in a balancer chamber mounted on one side of the crankcase. The upper and lower cases define substantially semicylindrical recesses therein which jointly constitute bearings in which the crankshaft and the balancer shaft are rotatably supported.

Abstract: An engine construction which comprises a cylinder block having a series of bearing seats formed therein for the support of a crankshaft, a lower block having bearing caps formed integrally therewith and adapted to be secured from below to the cylinder block with the bearing caps aligned with the corresponding bearing seats for the support of the crankshaft, a balancer shaft, a drive transmitting unit for transmitting the drive of the crankshaft to the balancer shaft, and an oil pan adapted to be removably fitted from below to the lower block and positioned on one side of the lower block opposite to the cylinder block. A surface region of the cylinder block and a mating surface region of the lower block which is brought into contact with the surface region of the cylinder block when the cylinder block and the lower block are connected together are formed with respective pluralities of bearing recesses for the support of the balancer shaft.

Abstract: In an internal combustion engine, in the crankcase (2), as shown in FIG. 1, each bearing cap (7) supporting a crankshaft bearing is, in each instance, bolted to its bearing web (4) with only a single screw (8). On the side of the bearing cap (7) opposite the screw (8), there is provided on the bearing web (4) a supporting surface (11), against which the bearing cap (7) abuts, so that some of the forces parallel to the cylinder axis can be conveyed directly into the crankcase (2).

Abstract: An internal combustion engine comprises reinforcing means secured to an edge portion of a lower opening of the cylinder block at a peripheral edge portion thereof. The reinforcing member has a plate-like shape, has connecting parts extending laterally with respect to the direction of the engine for connecting the facing edge portions of the lower opening of the cylinder block and is formed with openings for passage of oil at the front portion thereof and is secured to an oil pan at the lower surface of its front portion. The rear portion of said reinforcing means forms a part of an outer lower wall of a crank case containing a crank shaft and bifurcates into an upper branch extending backwardly and upwardly and a lower branch extending backwardly and downwardly. The upper branch has an end portion for connection with the cylinder block and the lower branch has an end portion for connection with a transmission case.

Abstract: Rigidifying or structural members are used to increase structural stiffness of cylinder block and consequently have reduced vibrations and noise emitted therefrom. These devices in the past have reduced serviceability, increased engine component complexity, increased cost and allowed additional interfaces for lubricant to leak therefrom. The subject structural member or rigidifying member provides a simple, inexpensive, light-weight solution to increasing structural stiffness of cylinder block. The subject structural member has an uninterrupted flange therearound and a plurality of equally spaced longitudinally positioned openings therethrough. The flange is secured in frictional contact with the inner mounting surface inside the oil pan. Thus, the interface for lubrication leakage of past members has been eliminated. The openings have reduced the weight of the member and provide an opening through which the crankshaft can swing preventing the need to increase the engine height.