Abstract:
In a ratchet-type tensioner, a rocking ratchet pawl is released from a rack of teeth on a tensioner plunger following engine start-up by a hydraulically operated pin slidable in a pin hole and caused to protrude therefrom by oil under pressure received directly from an external oil supply, or alternatively from the tensioner's high pressure oil chamber through a passage in the tensioner housing. Optionally, an orifice can be provided within the pin hole to control flow of oil when the supply is excessive and to avoid leakage when the supply is insufficient.
Abstract:
In chain and sprocket systems with at least two resonance modes, two or more tension reducing sprockets are oriented to cancel each other at a first resonance mode and have no effect to increase tensions at such first resonance mode. The tension reduction sprockets, however, are oriented with each other so that tensions will be reduced at a second resonance mode. Hence, two or more tension reducing sprockets are used to reduce tensions at a second resonance mode from sources outside the chain and sprocket system while minimizing tension increases at first resonance mode.
Abstract:
A fuel-pump-driving device (20) drives a plunger (31) of a fuel pump (30) to perform a reciprocating motion to supply fuel to an internal combustion engine. The fuel-pump-driving device (20) comprises a cam (27) that drives the plunger (31) according to the rotation of a fuel-pump-driving sprocket (26). The fuel-pump-driving sprocket (26) meshes with a chain (7A) which travels between a crank sprocket (3) and a valve-driving sprocket (5A) of the engine. Since the fuel-pump-driving sprocket (26) can be located in a position detached from the valve-driving sprocket (5A), the fuel-pump-driving device (20) has greater freedom of layout and the fuel pump (30) exhibits a better performance than in a case where the plunger (31) is driven by a cam that is fixed directly to the cam shaft (5) of the valve-driving sprocket (5A).
Abstract:
In a timing chain drive, a hybrid driving sprocket, having roller-engaging teeth and side sprocket teeth, cooperates with a hybrid chain having rollers that mesh with the roller-engaging teeth and toothed link plates that mesh with the side sprocket teeth. A driven sprocket from which the chain travels toward the driving sprocket has a cyclically varying tooth pitch that compensates for tension variations due to cyclic variations in the rotational speed of the driving sprocket or to cyclic variations in the load applied to the driven sprocket. The driven sprocket can be a roller sprocket or a hybrid sprocket having roller-engaging teeth and side sprocket teeth for engagement with the teeth on the link plates of the chain.
Abstract:
A rocker arm is mounted to an eccentric shaft. The shaft has a pair of ends which are mounted to corresponding supports. The shaft has a rocker arm seat portion which is eccentric to the end portions, whereby when the position of the shaft is changed by rotating it, the position of the rocker arm changes. The shaft ends are mounted to riser blocks which are connected to a support structure. The shaft ends may be clamped in a fixed position relative to the riser blocks, or unclamped to permit the shaft to be rotated. When rotated, the position of the rocker arm may be changed up or down relative to the support structure and a valve stem which the rocker arm is intended to engage, thereby adjusting valve clearance.
Abstract:
An outboard engine unit includes a single lubricating oil supply tube for supplying lubricating oil to a valve-operating chain. The valve-operating chain is suspended across a drive sprocket provided to a crankshaft and a driven sprocket provided to a camshaft. A supply tube is connected to a main gallery that is linked to a main oil channel positioned in an area adjacent to the crankshaft.
Abstract:
A compliant gear assembly includes a gear ring positioned about a hub and configured to translate responsive to a torque on the gear assembly, and biased toward co-axial alignment with the hub via at least one actuator. A method of managing loads on an idler gear in the gear train is still further provided including translating the gear ring responsive to the torque on the idler gear. A work machine includes an engine having a housing and a geartrain mounted thereon, the geartrain including a crank gear, a cam gear and a compliant idler gear assembly.
Abstract:
A decompression mechanism provided in a valve operating system configured to drive a valve for opening and closing a port, includes an accommodating member provided in the valve operating system; a decompression member which is accommodated in the accommodating member such that the decompression member is extendable and retractable, the decompression member being configured to extend from the valve operating system to press the valve to open the port in a compression stroke of the engine; and an insertion member which is inserted into the valve operating system, the insertion member being configured to be inserted through the accommodating member in a direction crossing a direction in which the decompression member is extendable and retractable.
Abstract:
In a hydraulic tensioner having a relief valve inside its plunger, a relief valve spring-receiving plug, press-fit into the plunger is formed by forging a plurality of flat surfaces on its exterior. These flat surfaces, in cooperation with the cylindrical inner wall of the plunger, form plural oil passages, each having a segment-shaped cross-section. The oil passages allow flow of oil past the plug to a discharge opening at the front end of the plunger, and the flow of oil is substantially unaffected by circumferential displacement of the oil passages on the periphery of the plug relative to the oil passages on the periphery of the relief valve seat.
Abstract:
A device for setting the relative rotational position of a camshaft (2, 3) of an internal combustion engine (11) relative to a crankshaft (1) driving the camshaft (2, 3), having a traction mechanism drive (4) wrapping around the crankshaft (1) and the camshaft (2, 3), which includes a loaded traction-mechanism section (8, 9) and a non-loaded traction-mechanism section (7), and a tensioning device (5, 6, 10) for changing the length of the loaded traction-mechanism section (8, 9). The tensioning device (5, 6, 10) is supported on the internal combustion engine (11) and has an adjustment device (20) that can be fixed.