Design Method of Oil Pump Rotor for Noise Reduction

Abstract

The present invention relates to a method for designing oil pump rotors, which is capable of obtaining a noise reduction effect. An oil pump is a rotary gear pump and is provided with an outer rotor and an inner rotor; the internal periphery of the outer rotor forms a plurality of convex angles; the inner rotor performs eccentric rotating in an inner side space of the outer rotor. The method comprises the steps of: (a) designing a dedendum shape of the lobes of the outer rotor in a shape of combining an ellipse and an involute curve, and designing the teeth of the inner rotor according to the designed dedendum shape of the lobes of the outer rotor, wherein the outer and inner rotors are designed such that an addendum of the lobes of the outer rotor where a carry-over effect occurs is identical to the shape of the inner rotor; (b) calculating contact stress for each design variable when varying the design variables applied in the step (a), using a contact stress formula of the inner and outer rotors; and (c) calculating the slippage rates of the inner and outer rotors for each design variable when varying the design variables applied in the step (a).

Description

technical field [0001] The present invention relates to a design method for a rotary gear (gerotor) of an oil pump, and more particularly relates to a method for designing a rotor for an automotive oil pump, so that the lobe of the outer rotor has a combined ellipse and involute curve form, and at the same time, through the analysis of the slip ratio and contact stress for eliminating the carry-over, the design method of the rotary gear pump rotor capable of reducing noise, the rotor for reducing noise according to the present invention will be Design method, the rotor profile manufactured by the automated system is named "SPDICHOID (trade name)". Background technique [0002] The lubricating device of the automobile engine is a necessary device to make the engine run smoothly and maintain a long life. As one of the structural parts of this lubricating device, the oil pump is mainly used in terms of flow rate, durability, noise and miniaturization. Inner cut oil pump. This...

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Problems solved by technology

[0005] However, in the existing ellipse-involute combination method disclosed in the said authorized patent, the discontinuity of the curve occurs at the point where the ellipse and the involute meet, which causes problems such as increased noise and reduced durability.

[0006] Moreover, most of the existing rotary gear tooth design technologies of oil pumps focus on improving the flow rate and flow pulsation. Therefore, no special effect has been achieved on the improvement of the noise problem that has been more concerned recently.

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