Wear’s issues on high-pressure common rail pumps

Abstract

High-pressure pumps are the most important components of modern fuel injection systems. A modern system is the common rail one, equipping vehicles with a diesel or a gasoline engine. Depending on the fuel type, the design of the pumps is completely different, and it is more complex for diesel engines that are more prone to wear. The components subjected to wear are those in contact and continuous motion like drive shaft with roller and shoe, plunger and hydraulic head assembly with valves. Wear is initiated as a result of a process and product deviations or inadequate exploitation of the high-pressure pump. The factors influencing the wear can be improper material hardness, improper coating, incomplete or wrong machining, wrong clearance or misalignment between components, inadequate surface finish, dimensions out of tolerances, wrong assembly process, poor lubrication, contamination or running at high loads and temperatures. Our paper aims to identify, describe and discuss the types of wear encountered at common rail high-pressure pumps, highlighting the effects on their functionality. The wear occurrence can be prevented by paying more attention to the design details, manufacturing processes and correct exploitation of the high-pressure pumps.

A Study on Water-Induced Damage Severity on Diesel Engine Injection System Using Emulsified Diesel Fuels

“…Against the cost-effectiveness of diesel fuel emulsification, concerns about the right W/D ratio, and more importantly, the inherent engine power loss, component corrosion, seal damage, and other injection system problems associated with the practice, still remain [15][16][17]. Although some may argue otherwise, the compelling yet contradictory arguments only further motivated this study.…”

Filmes de DLC-Si e TiN-MoS₂ para redução do desgaste em sistema de injeção de combustível

“…O interesse pela utilização de filmes de DLC está na sua alta dureza e baixo coeficiente de atrito contra metais, funcionando como um revestimento auto lubrificante (HOLMBERG e MATTHEWS, 2009). Suas propriedades mecânicas e tribológicas têm sido amplamente aplicadas no universo automotivo, em componentes de alto desempenho e de geometria complexa, como dos eletroinjetores e da bomba de alta pressão, visando mais durabilidade (MEEK et al, 2014;IORDACHE et al, 2020). Alguns estudos indicam que a aplicação do DLC junto ao Si por técnica PECVD promove a redução da tensão residual e uma melhor coesão entre o filme e o substrato sem prejuízos para a dureza (DAMASCENO et al, 2000; SANTOS e CAMARGO JR., 2018).…”

Operation Cycle of Diesel CR Injection Pump via Pressure Measurement in Piston Working Chamber

“…About pump structure, tribology, and noise, reference [22] deals with the tribological aspects of the piston-cylinder pair, taking the characteristics of the contact surfaces into account. In [23,24], the effects of plunger micro-motion (offset and inclination) on pump operation are investigated by modeling. Reference [24] reports the types of wear encountered in CR high-pressure pumps, highlighting the effects on their functionality.…”

“…In [23,24], the effects of plunger micro-motion (offset and inclination) on pump operation are investigated by modeling. Reference [24] reports the types of wear encountered in CR high-pressure pumps, highlighting the effects on their functionality. In [25,26], the role of wear in pump noise emission is analyzed, pointing out that the opening of the pump delivery valve is the greatest contributor to noise emission.…”