High pressure fuel pump driving structure

Abstract

The invention provides a high pressure fuel pump driving structure of an engine. The high pressure fuel pump driving structure comprises a spiral gear with an internal spline, a casing pipe with an external spline, a sliding sleeve, and a fixing sleeve. The casing pipe is fixedly installed on a pump shaft of a high pressure fuel pump, and the external spline of the casing pipe is in clearance fit with the internal spline of the spiral gear so that the spiral gear can slide relative to the casing pipe in the axial direction. The sliding sleeve and the fixing sleeve are sleeved together coaxially and can slide relatively axially. One end of the sliding sleeve abuts against the spiral gear. A pre-pressing spring is arranged between the sliding sleeve and the fixing sleeve. The high pressure fuel pump driving structure can effectively bear and avoid axial force generated when the spiral gear is adopted for driving the high pressure fuel pump, and therefore the spiral gear is applicable to the high pressure fuel pump and can lower noise of the engine.

Description

technical field [0001] The invention relates to the field of engines, in particular to a driving structure of a high-pressure fuel pump driven by a helical gear. Background technique [0002] Engines are widely used in various technical fields, especially in the automotive field. With the increasingly stringent emission regulations at home and abroad, high-pressure common rail fuel systems are widely used in vehicle diesel engines. The high pressure fuel pump is driven by timing system gears or sprockets, belt. In recent years, in order to effectively reduce the noise of the engine, there has been a trend of changing the timing system of the engine from the original spur gear to the helical gear drive. In the Chinese invention patent application for "diesel engine oil pump transmission system", helical gears are used in the timing system. [0003] Since the pump shaft of the high-pressure fuel pump generally cannot bear the axial force, it is necessary to offset or compen...

AI Technical Summary

Problems solved by technology

However, if the timing system adopts helical gears, compared with spur gears, the helical gears suffer from greater axial component force, so the elimination of axial force and displacement compensation become the primary issues to be considered in the design, and if still If the connection of the cross slider is used, the influence of the axial force is more significant when the engine is accelerated, decelerated, or the load is suddenly changed due to changes in other conditions such as road bumps. The amount of axial play between the shaft and the drive shaft is larger and more frequent, which is not only more prone to wear and shortens the life, but also creates a collision between the pump shaft and the drive shaft, reducing the noise reduction effect of the helical gear

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