Displacement Pump Pressure Control Device for Noise Reduction
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Solution Overview
Problem
Displacement pumps experience pressure pulses and vibrations due to rapid pressure changes across the control ring, leading to disturbing noises, as existing solutions compromise on pre-compression and pre-decompression, resulting in suboptimal performance at various control positions.
Innovation Solution
A pressure control device that adjusts the perceived length of the land between the high and low pressure sides of the control ring by varying the size of the through holes, allowing for dynamic control of pressure chamber blocking time based on the control ring's position, thereby minimizing pressure pulses and vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the land is adapted to give ideal pre-compression in an intermediate position of the control ring, then the pre-compression is optimized for that specific position, but the pre-compression becomes too large or too small at other control positions, causing pressure pulses, vibrations and disturbing noises
Solution Approach 1:
The patent applies the dynamics principle by making the land width variable instead of fixed. The land width is designed to vary depending on the control position of the control ring, allowing the system to adapt pre-compression levels dynamically. This is achieved through a specifically contoured land geometry that provides different effective widths at different angular positions, enabling optimal pre-compression at each control position rather than compromising with a single fixed dimension
Solution Approach 2:
The patent applies local quality by creating non-uniform land geometry along the circumferential direction. Different sections of the land have different widths, with the land being wider in some angular regions and narrower in others. This local variation in land width allows each section to provide appropriate pre-compression for its corresponding control position, resolving the contradiction between optimized pre-compression and adaptability across positions
2Productivity
If the control ring is arranged for 0% displacement, then the pressure rises very rapidly over the land, but this causes high pressure differences between the opening of the pressure chamber and the opening in the control ring, leading to vibrations and disturbing noises
Solution Approach 1:
The variable land width dynamically adapts to different displacement settings. At 0% displacement positions, the land is designed to be wider, providing gradual pre-compression that reduces pressure differences and prevents rapid pressure rises. This dynamic adaptation eliminates the harmful pressure pulses and vibrations that would otherwise occur at extreme displacement positions
Solution Approach 2:
The patent applies preliminary anti-action by implementing pre-compression through the land geometry before the pressure chamber openings align with the control ring openings. This preliminary action gradually equalizes pressure differences in advance, preventing the sudden pressure changes that cause vibrations and noise, particularly at 0% displacement positions where the land's geometry provides缓冲 (buffering) effect
Data Source
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AI summary
The present invention refers to exemplary embodiments of a pressure control device, a displacement control arrangement and a pumping arrangement, wherein the displacement control arrangement is part of the pumping arrangement and comprises a control ring, a rear face of a pump unit and the pressure control device. The rear face of the pump unit may belong to any type of pump unit comprising pressure chambers. The pressure control device is provided with a plurality of rotation symmetrically arranged through holes. Respective through hole is defined by a circumferential inner surface, wherein the circumferential inner surface of the through hole is provided with at least one protrusion extending into the through hole such that a midsection of the through hole has a smaller extension in an intended rotational direction than an outer section and an inner section of the through hole. The pressure control device is fixedly arranged to an axial surface of the rear face of a pump unit and the second axial surface of the pressure control device is facing an axial surface of the control ring. The rear face of a pump unit and the pressure control device are rotational symmetrically arranged about a first rotational axis and the control ring, which is provided with at least a first and a second opening formed as semi-circular arcs, and which are separated by a first and a second land, is rotational symmetrically arranged about a second rotational axis, wherein the second rotational axis is radially offset by a distance E in relation to the first rotational axis, and is arranged in parallel to the first rotational axis. Due to the radial offset between the first and second rotational axis, and due to the configuration of the through holes, by changing the displacement of the displacement pump the angular distance, thus the period pf time, the through holes are completely blocked by the first and second lands may be varied.