摘要:
In one aspect, the present disclosure is directed to a tappet assembly for a machine. The assembly may include a tappet body, a pin fixedly mounted in the tappet body, and a substantially cylindrical roller mounted about the pin. The roller may have a substantially cylindrical outer surface with a circumferential dimension and a width dimension, the width dimension being defined by two lateral edges. The roller may be configured to provide rolling contact between the outer surface of the roller and a cam lobe. The outer surface of the roller may be crowned such that at maximum operational loading conditions of the machine a footprint of contact pressure from the cam lobe is spread substantially the full width of outer cylindrical surface of the roller.
摘要:
A method of operating a fuel system for a compression ignition engine includes supplying biofuel, which may be part of a mixture, to an inlet of a fuel lubricated pump. At least one bearing of the pump is lubricated with the biofuel. The fuel lubricated pump supplies high pressure fuel to a common rail. A plurality of fuel injectors are fluidly connected to the common rail, and each include at least one nozzle orifice for injecting the biofuel into the combustion space of the engine. Nozzle orifice coking is limited at least in part by employing a spinodal bronze alloy in the bearing of the fuel lubricated pump.
摘要:
A dual fuel system includes a dual fuel injector that has disposed therein a gaseous nozzle chamber fluidly connected to a gaseous fuel inlet, and a liquid nozzle chamber fluidly connected to the liquid fuel inlet. The dual fuel injector also includes a hydraulic lock seal with an annular volume of liquid fuel surrounding a guide segment of a gas needle valve member for inhibiting migration of gaseous fuel into the liquid fuel. A liquid fuel common rail is fluidly connected to a liquid fuel inlet. A check valve is fluidly positioned between the gaseous fuel common rail and the gaseous nozzle chamber of the dual fuel injector for blocking liquid fuel leaked into a gaseous nozzle chamber through the hydraulic lock seal from entering the gaseous fuel common rail.
摘要:
The disclosure describes an engine system having liquid and gaseous fuel systems, each of which injects fuel directly into an engine cylinder. A controller monitors and controls engine operation in a normal mode, during which the engine produces rated power, and in a limp-home mode, which is used when an abnormal operating condition of the gaseous fuel system is present. During limp-home mode operation, the engine uses more liquid fuel and less or no gaseous fuel relative to the normal mode, and produces power that is less than rated power.
摘要:
A fuel injector configured to inject a predetermined volume of fuel, such as heavy fuel oil, is disclosed. The disclosed injector includes an injector body that defines a fuel inlet, a fuel passageway, and an orifice. The injector also includes a needle disclosed at least partially within the injector body. The needle is movable between a closed position where the needle blocks the orifice and an open position where the needle at least partially unblocks the orifice. At least the injector body and the needle define a nozzle chamber. The nozzle chamber is in communication with a high pressure fuel passageway and the orifice. The fuel passageway and nozzle chamber have a combined volume greater than the predetermined injection volume. The combined volume of the nozzle chamber and fuel passageway act as a damper to alleviate the effects of pressure overshoot, pressure oscillations and water hammer
摘要:
A fuel system includes a plurality of fuel injectors each defining a nozzle supply passage, a nozzle outlet and a low pressure space. The fuel system includes a plurality of mechanically actuated pressure intensifiers each including a tappet and being positioned partially within one of the fuel injectors, and a common rail fluidly connecting with each of the fuel injectors. Each of the fuel injectors further includes an injection pressure control mechanism having an injection pressure control valve. Each injection pressure control valve blocks the corresponding pressure intensifier from the common rail and fluidly connects the pressure intensifier with the low pressure space at a first position, and fluidly connects the pressure intensifier with the common rail and blocks the pressure intensifier from the low pressure space at a second position. Injecting fuel via operating the fuel system may include operating the fuel system in a low leakage mode where the pressure intensifier displaces fuel at a low pressure, between high pressure injections.
摘要:
Mixing of lubrication fluid and pumped fluid within a pump can undermine lubricity of the lubrication fluid and/or contaminate the pumped fluid (e.g. fuel) with lubrication fluid. In order to reduce mixing of fluids within a high pressure pump of the present disclosure, a lubrication fluid is supplied to the high pressure pump. A low pressure pump supplies a second fluid to the high pressure pump. The pressure of the second fluid is increased within at least one piston bore of the high pressure pump. Mixing of the lubrication fluid and the second fluid is reduced by fluidly connecting a weep annulus which is opened to the at least one piston bore to a low pressure pump inlet of the low pressure pump.
摘要:
A valve has a housing defining an interior of the valve. The valve has a first passage in the housing and a second passage in the housing. The valve has a flow limiter movable between a first position at which the first passage is in fluid communication with the second passage and a second position at which the first passage is not in fluid communication with the second passage. The valve has a flow restriction device movable between a first position at which a first flow rate is permitted into the interior of the valve and a second position at which a second flow rate is permitted out of the interior of the valve. The first flow rate is greater than the second flow rate.
摘要:
A method is provided for predicting a quality characteristic of a product to be manufactured. The method may integrate one or more of feature and tolerance information associated with the product, manufacturing characteristic information associated with the manufacture of the product, measurement capability characteristic information associated with the manufacture of the product, assembly characteristic information associated with an assembly of the product, and desired quality characteristic information associated with the product. Based on the integrated information, the quality characteristic of the product may be predicted.
摘要:
A pressure relief valve includes a valve body defining an inlet configured to receive fluid from a fluid system, a pressure control orifice ending in a valve seat, and a guideway extending from the valve seat. The pressure relief valve further includes a valve closing member configured to abut the valve seat in a closed position and to be displaced from the valve seat in an open position, thereby releasing pressure from the fluid system. The pressure relief valve also includes a flow member including a stem and a flow plate. The stem is operably associated with the valve closing member and is configured to reciprocate within the guideway. The pressure relief valve further includes a valve spring operably associated with the valve body.