Abstract: A lubricating system for an outboard motor equipped with a vertical type engine. In one embodiment, the lubricating system has an oil pump positioned near the bottom of the engine, the oil pump driven by an oil pump rotor that is positioned at a connection between the crankshaft and an engine drive-shaft, the oil pump rotor being linked to the crankshaft. The system further includes a camshaft-driving mechanism for transmitting the rotation of the crankshaft to a propulsion device. The camshaft-driving mechanism is also positioned at the connection between the crankshaft and the drive-shaft and is also linked to the crankshaft. The lubrication system also has a main oil tank for storing lubricating oil circulated by the oil pump, and an engine-cooling water passageway positioned next to the main oil tank. Another element of this embodiment of the lubricating system is a filter-mounting base positioned on an outer wall of the cylinder blocks.

Abstract: To reduce the size and weight of an oil tank for a dry sump type lubricating system. A separate oil tank of a dry sump type lubricating system is mounted on the front surface of a front case cover constituting part of a crankcase divided into front and rear parts. An effective volume portion, in which oil supplied from the crankcase side via scavenging pumps and cooled by an oil cooler is contained, is provided in the oil tank. The bottom portion of the effective volume portion is connected to a feed pump on the crankcase side via an outlet side passage. A tank side pipe portion extending rearwardly through the oil tank is integrally provided at a portion of the oil tank higher than the oil level in the oil tank. The tank side pipe portion is connected to a crankcase side pipe portion integrally provided on an upper portion of the front case cover to form an overflow passage.

Abstract: A method and system for continuously replacing engine oil in an internal combustion engine includes an oil replacement cylinder which uses positive displacement of new oil with old oil. The oil valve may be reduced to a fraction of typical oil volumes utilized in prior art lubrication systems.

Abstract: A crankcase with a ceiling portion for shutting off the upper side of an oil pool chamber. An oil flowing window is opened in the ceiling portion of a right case. An oil strainer is formed in a flat plate like shape. The oil strainer is fitted to the oil flowing window. The right case is provided with an oil passage through which the oil having passed through the oil strainer flows roughly horizontally to an oil pump suction port. The ceiling portion of the right case is provided with a cutout portion by not casting a portion of the case at a position where the ceiling portion of the right case and an oil pump are adjacent to each other, and a plug is fitted in the cutout portion. The vertical size from the oil pool to the oil pump suction port can be reduced as much as possible, and the overall height of the internal combustion engine can be restricted.

Abstract: A lubrication system for supplying a portion of the engine lubricant to one or more gear devices driven thereby and return to the engine independent of whether the gear devices are being driven at the time. Thus even when the engine is idling engine lubricant is circulated through the gear devices to maintain the temperature of the lubricant circulating through the gear devices within a relatively narrow temperature range. Also, the lubricant level within the gear devices will be maintained without the need for inspection of the gear devices as long as the engine lubricant level is regularly checked and maintained either manually or automatically. Further, by changing the engine lubricant at regular service intervals or using an automated lubricant change system, the quality and level of the lubricant in the gear devices is also maintained.

Abstract: An oil tank of large capacity is integrally mounted directly to a front side of a front case cover in a power unit including a hydrostatic type continuously variable transmission. The power unit is driven by a crankshaft within a crankcase, and a lower portion of the oil tank is connected through an inlet and an outlet both formed in the front case cover to an oil pump disposed inside the front case cover in order to dispense with piping and fittings required when a tank is located separately from a power unit.

Abstract: A balancer shaft apparatus efficiently prevent oil from being stirred in the oil pan and from being splashed into the cylinder block during the balancer-shaft rotation. Oil in a housing of the balancer shaft is discharged from a drainage hole formed at such a location above an oil level as to contact a base serving as a bearing beam of a crankshaft supporting member. The discharged oil hits inner surfaces of a recess formed on the lower portion of the crankshaft supporting member to form oil drops, returning to an oil pan. The housing is provided with guide passages connecting the drainage holes to a space in which the balancer shaft is disposed for draining the oil. These guide passages are formed with tapered guide surfaces for orienting the oil towards the lower portions of the crankshaft supporting member while splashed oil caused by the balancer-shaft rotation is drained through the drainage holes.

Abstract: The invention relates to an internal-combustion engine, in particular for motorcycles, with a crankshaft (24) which is arranged in a crankcase (10, 14) and which is connected by way of connecting rods (20, 22) to pistons arranged so as to be movable in cylinders (16, 18), with an oil sump (12) which is situated below the crankcase (10) and from which the lubricating oil is conveyed to the consumer devices by way of an oil pump (60), and with means for returning the lubricating oil from the consumer devices to the oil sump (12). It is proposed that, in order to separate the oil taken up in particular by the crankshaft (24), a part of the crankcase (10) adjacent to the crankshaft (24) has a wall portion (26a to d) which extends parallel to the axis of rotation of the crankshaft (24) and the outline of which is adapted to the enveloping curves of the crankshaft webs (27, 28) and/or the connecting rods (20, 22). A rapid return of the lubricating oil to the oil sump is made possible by this step.

Abstract: An improved lubrication arrangement for an internal combustion engine of the push tube (59) type. A carrier structure (43) is fixed relative to an upper surface of the cylinder head (31) and includes a fixed fulcrum location (49) for each rocker arm (51). The carrier structure (43) defines a lubrication passage (67,69) providing lubrication fluid to the fixed fulcrum location (49). The engine block (11) and the cylinder head (31) cooperate to define a fluid chamber (81) surrounding the push tube (59). Lubrication fluid flows out adjacent the fixed fulcrum location (49) and flows under the influence of gravity into the fluid chamber (81). The push tube defines a plurality of openings (83) whereby lubrication fluid flows from the fluid chamber (81) into the interior (85) of the push tube.

Abstract: This engine is substantially free from any vibration and noise, small in friction loss, improved in mechanical efficiency to a considerable extent, compact and lightweight, and applicable to a reciprocating piston engine. The engine comprises: curved cylinders each assuming a circular shape in cross section; curved pistons (1, 1a) each fitting and reciprocating within the cylinder; a rotor (2) carrying the pistons (1, 1a) to keep them in balance and to have them be rockable about the center of the rotor (2), wherein the rotor (2) is provided with connecting rods (6, 6a) to impart half a rocking power of the rotor (2) to each of crank shafts (10, 10a) each of which converts the half of the rocking power to a piece of torque on its axis of rotation; a gear mechanism for receiving the pieces of torque to combine them into an output power; and, an output shaft connected with the gear mechanism for receiving and out-putting the output power.

Abstract: An object of the present invention is to provide an improved lubricating method and device for the internal combustion engine, which allows the engine to be lubricated by taking advantage of engine vibration without using other power source. The lubricating device includes a crankcase separated into a crank chamber and an oil reservoir by a partition wall. The partition wall has an opening provided with a wire net for covering the opening. A coil spring is suspended within the oil reservoir so as to form a U-shape. During operation, an engine vibration induces a vibration of the coil spring, and the oscillating coil spring agitates and/or splashes up an engine oil contained in the oil reservoir, and whereby an entire oil surface is ruffled. The engine oil introduced into the crank chamber impinges on a crankshaft and finer droplets or oil mist is formed to thereby lubricate the crankshaft and other engine components.

Abstract: A scraper is provided in a large end portion of a connecting rod in an inclined type of overhead camshaft engine to lubricate a timing system by dipping a lubricating oil stored in a lower portion of a crank case up. The scraper includes a bottom wall and a side wall set up on the bottom wall, and have a substantially L-shaped cross-section. An angle between the bottom wall and the side wall is set in a range of 60° to 90°. Thus, the droplets of the oil can be splashed to the side direction of scraper also in three-dimensional inclined direction, so that oil can be securely supplied to and lubricate the timing system which is offsetted from the scraper in a longitudinal direction of the crankshaft.

Abstract: A crankcase is provided with a ceiling portion for shutting off the upper side of an oil pool chamber. An oil flowing window is opened in the ceiling portion of a right case. An oil strainer is formed in a flat plate like shape The oil strainer is fitted to the oil flowing window The right case is provided with an oil passage through which the oil having passed through the oil strainer flows roughly horizontally to an oil pump suction port. The ceiling portion of the right case is provided with a cutout portion by not casting a portion of the case at a position where the ceiling portion of the right case and an oil pump are adjacent to each other, and a plug is fitted in the cutout portion. The vertical size from the oil pool to the oil pump suction port can be reduced as much as possible, and the overall height of the internal combustion engine can be restricted.

Abstract: To reduce the size and weight of an oil tank for a dry sump type lubricating system. A separate oil tank of a dry sump type lubricating system is mounted on the front surface of a front case cover constituting part of a crankcase divided into front and rear parts. An effective volume portion, in which oil supplied from the crankcase side via scavenging pumps and cooled by an oil cooler is contained, is provided in the oil tank. The bottom portion of the effective volume portion is connected to a feed pump on the crankcase side via an outlet side passage. A tank side pipe portion extending rearwardly through the oil tank is integrally provided at a portion of the oil tank higher than the oil level in the oil tank. The tank side pipe portion is connected to a crankcase side pipe portion integrally provided on an upper portion of the front case cover to form an overflow passage.

Abstract: An oil passage extending from an oil pump to a discharge port in an internal combustion engine is, at its halfway point, branched into at least two oil passages, for example, a first oil passage and a second oil passage. One of the at least two branched oil passages, for example, the second oil passage is provided with a restricting portion configured as a first orifice for restricting a flow amount of oil by reducing a diameter of the first orifice. A bypass valve is provided which acts, when a hydraulic pressure in the second oil passage exceeds a specific value, to bypass the first orifice so as to increase the flow rate of oil. It is possible to increase the hydraulic pressure at the time of low speed rotation up to a necessary pressure only by providing the restricting portion, without enhancing the performance of the oil pump.

Abstract: An engine lubrication system is provided which has an oil pump for supplying lubricating oil from an oil pan to an area that is to be lubricated, the oil pump being positioned outside the oil pan and driven by a camshaft. An oil passage formation member fitted to the lower face of an engine block so as to be housed in the oil pan, comprises an oil inlet passage for taking in oil from the oil pan to the oil pump and a relief valve for discharging excess oil discharged by the oil pump via an oil supply passage. When the relief valve opens, the excess oil is not directly discharged to the oil pan but is returned to the oil inlet passage from the oil supply passage via a connecting path. The space required for housing a vertical engine, and in particular in the vertical direction, can thus be reduced and the formation of bubbles in the oil inside the oil pan due to the oil discharged by the relief valve through the oil supply passage, can be prevented.

Abstract: A lubricating oil feed passage in a crank shaft, having lubricating oil passages formed in the crank shaft and having an inlet end and an outlet end which is open to a connection surface of a crank pin for connection with a connecting rod, a bolt secured to an end portion of the crank shaft so as to project in an axial direction of the crank shaft from an end face of the shaft end portion, and a lubricating oil introducing passage formed axially through the bolt and connected to the inlet end.

Abstract: A lubrication structure for an internal combustion engine including an oil pump provided at a first end of an oil pump shaft arranged parallel to a crankshaft. Oil passageways are formed from a side surface of a pump chamber of the oil pump to another end of the oil pump shaft in parallel with the oil pump shaft. An oil filter is provided facing towards the oil passageways. A communicating passageway extending vertically from the oil passageways to the oil filter is also provided. This arrangement provides a lubrication structure for an internal combustion engine with a high degree of freedom with respect to oil filter arrangement with a simple oil passageway that is easy to manufacture, requires relatively small space for arrangement, and thus makes it possible to reduce the size of the internal combustion engine.

Abstract: An oil passage for an internal combustion engine having a timing chain entrained around a crank sprocket and a cam sprocket, the crank sprocket being mounted on a crankshaft of the engine, and the cam sprocket being positioned on a camshaft. A timing case is disposed on one side of the engine for enclosing the timing chain. The oil passage for supplying the engine oil to the actuator is connected at an upstream side thereof to a downstream side of an oil pump, while a downstream side of the oil passage is positioned inside the timing case and around the cam sprocket.

Abstract: A piston-driven oil pump mechanism constructed to simplify structure and reduce parts for increased compression efficiency but drastically reduced generating of noise, the mechanism comprising: an oil pump cylinder additionally mounted at one side of a cylinder block formed with a cylinder where a piston is reciprocally driven by explosion in a combustion chamber; an oil pump piston reciprocally driven in the oil pump cylinder by a crank shaft where reciprocal motion of the piston is changed rotary motion; an oil drainage outlet so formed to communicate with an oil gallery above the oil pump cylinder; an oil suction inlet formed adjacent to the oil outlet above the oil pump cylinder for connection to an oil pan; and oil suction and oil drainage valves openably and closeably actuated by a valve train for opening the oil suction inlet when the oil pump cylinder is downwardly actuated to block the oil drainage outlet and for closing the oil suction inlet when the oil pump cylinder is upwardly actuated to open th

Abstract: To provide a multi-cylinder engine in which cam shaft linked with a plurality of intake valves and a plurality of exhaust valves for carrying out intake and exhaust operations for a plurality of combustion chambers is rotatably supported by cam bearing portions provided on the cylinder head and a cam holder fastened to the cam bearing portions. An oil passage capable of supplying oil from an oiling passage provided in the cylinder head is formed in the cam shaft. Oil can be supplied in the oil passage in the cam shaft without restriction in the location of fastening bolts for fastening the cylinder head to the cylinder block. An oiling hole is provided in the cam shaft in such a manner as to be in communication with the oil passage, and an oil groove in communication with the outer end of the oiling hole is formed in a cam bearing portion, provided in the cylinder head, at a position corresponding to one of combustion chambers, in such a manner as to face toward the outer surface of the cam shaft.

Abstract: A hydraulic control valve mounting structure in an engine wherein a chain cover is attached to both a cylinder block and a cylinder head so as to cover a timing chain which transmits the rotation of a crank shaft to both intake and exhaust cam shafts. An oil pump is driven by the crank shaft, and a hydraulic control valve which supplies oil discharged from the oil pump to a hydraulic-actuated device in a hydraulic controller is attached to the chain cover. The hydraulic control valve mounting structure is such that the hydraulic control valve is attached to an outer surface of the chain cover while being positioned so that an upper portion thereof is covered at least partially with a mount installing boss portion of the chain cover.

Abstract: An oil-passage structure of an internal combustion engine which eliminates the necessity of drilling a hole through the chain cover or the tensioner bracket and allows the tensioner bracket to be moved to its proper position according to vehicle layout restrictions, and. maintains optimum functioning of the oil control valve by cooling the oil supplied thereto. The oil-passage structure includes an external oil pipe interconnecting the oil pump and the oil control valve and arranged between the auxiliaries machine driving belt and the chain cover.

Abstract: A push rod operated multi-valve V-type engine particularly adapted for use in motorcycles or like vehicles and which engine is air cooled. The engine employs a very simplified construction and overhead valve actuating mechanism utilizing push rods. The push rods are contained within push rod tubes formed at one side of the engine that provide a neat appearance and ease of servicing without adversely affecting the air cooling. A composite cylinder head construction is employed, as well as an improved and simplified lubricating system for the pair of driven camshafts. Furthermore, a decompression system is incorporated in the valve actuating mechanism so as to facilitate starting.

Abstract: An improved lubricating device for a four-stroke engine which permits the engine to operate upside down for a longer time and which has a better lubricating effect. This device comprises a first partitioning portion dividing the lubricating oil reservoir into a first and a second chambers, and a second partitioning portion further dividing the second chamber into a first and a second sub-chambers. The first partitioning portion includes a concave portion, having an opening for communicating the first chamber with the second chamber, which is adapted to receive some lubricating oil. Also, the first partitioning portion is provided thereon with a check valve which allows irreversible flow of the lubricating oil mist between the first chamber and the second sub-chamber.