Axial Piston Pump Geometry for Low-Noise Compact Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional axial piston machines generate significant noise due to pulsation of the flow and pressure, which is often mitigated at the expense of compactness.
Innovation Solution
Designing axial piston machines with specific ratios of pitch circle diameter to piston diameter, sweep angles, and reversing angles to minimize noise while maintaining compactness and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional axial piston machines are designed with standard pitch circle diameter to piston diameter ratios, then the machine structure is simple and compact, but significant noise is generated due to flow and pressure pulsation
Solution Approach 1:
The patent applies parameter changes by optimizing the pitch circle diameter to piston diameter ratio within a specific range (0.45-0.55) and controlling the number of pistons (6-12) to minimize flow and pressure pulsation. This quantitative parameter optimization reduces noise generation at the source while maintaining a relatively simple machine structure without requiring complex additional components.
Solution Approach 2:
The patent utilizes periodic action by carefully selecting the number of pistons (6-12) and their angular spacing to create overlapping discharge cycles. This ensures that when one piston completes its discharge, another is already beginning, thereby smoothing out pressure pulsations and reducing noise through the natural periodicity of the piston cycles.
2Object-generated harmful factors
If the pitch circle diameter to piston diameter ratio is increased to reduce noise, then noise is reduced, but the machine size increases and compactness is compromised
Solution Approach 1:
The patent resolves this contradiction by identifying an optimal parameter range for the pitch circle diameter to piston diameter ratio (0.45-0.55). Within this range, noise is minimized through reduced pulsation while the machine maintains compact dimensions. This eliminates the need to increase machine size to achieve noise reduction.
Solution Approach 2:
The patent employs multiple pistons (6-12) arranged in a specific angular pattern around the piston drum, creating overlapping discharge cycles that replicate and smooth out pressure variations. This multi-piston configuration achieves noise reduction through coordinated periodic action without requiring an oversized single-piston design.
3Volume of moving object
If the pitch circle diameter to piston diameter ratio is decreased to maintain compactness, then machine size is reduced, but noise increases due to increased pulsation
Solution Approach 1:
The patent establishes a lower bound (0.45) for the pitch circle diameter to piston diameter ratio below which noise increases. By maintaining the ratio within the optimal range, the design achieves compact dimensions while preventing excessive pulsation and noise through proper geometric scaling of the piston arrangement.
Solution Approach 2:
The patent uses a sufficient number of pistons (6-12) with specific angular spacing to ensure overlapping discharge cycles even at compact sizes. This periodic coordination of multiple pistons smooths pressure variations and reduces noise, allowing compact machine dimensions without sacrificing noise performance.
4Object-generated harmful factors
If the number of pistons is increased to reduce noise through overlapping cycles, then noise is reduced, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent utilizes periodic action by arranging 6-12 pistons at specific angular intervals around the piston drum, creating overlapping discharge cycles that smooth pressure pulsations and reduce noise. This approach achieves noise reduction through the natural periodic coordination of multiple pistons without requiring complex control systems or additional noise-mitigation components.
Solution Approach 2:
The patent optimizes the number of pistons within a specific range (6-12) to balance noise reduction with manufacturing feasibility. This quantitative parameter optimization ensures sufficient overlapping discharge cycles for noise control while avoiding excessive complexity in piston arrangement, bearing design, and manufacturing processes that would result from using significantly more pistons.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to an axial piston machine (1), in particular an axial piston pump, with a piston drum (2) that can be driven in at least one direction of rotation (22), with cylinders (10) arranged in the piston drum which are spaced apart from one another in the direction of rotation by a piston pitch (24) and are configured to slidably receive pistons (4) having a piston diameter (34), wherein the longitudinal axes (16) of the pistons are arranged parallel to one another on a pitch circle (28) having a pitch circle diameter (26), and wherein: 0.377zK ≤ DT,KdK ≤ 0.4948zK, where DT,K corresponds to the pitch circle diameter, dK to the piston diameter, and zK to the number of pistons. Such an axial piston pump is quiet in operation and yet compact.