Rotary Vane Pump Desmodromic Motion Reduces Wear
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Solution Overview
Problem
Radial vane pumps face issues with vane friction leading to wear and failure, particularly due to centrifugal forces and the need for rings or pistons, which cause additional wear and occupy space, limiting compactness and efficiency.
Innovation Solution
The design features diametric vanes that maintain constant contact with the stator profile, eliminating the need for rings or pistons by using a rotor and stator profile geometry that allows desmodromic motion, reducing centrifugal force and inertia, and enabling a more compact pump design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rings or pistons are used to maintain vane contact with the stator, then hermetic sealing is improved, but wear and failure increase due to amplified forces and friction
Solution Approach 1:
The invention removes the rings or pistons from the system entirely. The vane is designed to extend directly from the rotor to contact the stator profile without any intermediate retaining components. This extraction eliminates the source of force amplification and friction that caused wear, while the vane's direct contact with the stator maintains hermetic sealing through its own structural design and contact geometry.
Solution Approach 2:
The vane serves dual functions: it performs the pumping action by contacting the stator profile and simultaneously maintains its own position and sealing without requiring external rings or pistons. The vane's own geometry and the pressure differential across it provide the necessary forces to maintain contact and sealing, making the system self-sufficient and eliminating components that caused wear.
2Ease of operation
If rings or pistons are used to constrain vane motion, then desmodromic motion is achieved, but device complexity and space occupation increase
Solution Approach 1:
The invention extracts and removes the rings or pistons that were previously used to constrain and guide vane motion. The desmodromic motion is achieved purely through the geometric interaction between the vane, rotor, and stator profile, eliminating the need for additional constraining components and reducing structural complexity.
Solution Approach 2:
The functions of the vane and the constraining mechanism are merged into a single integrated component. The vane itself, through its geometry and positioning, performs both the pumping function and the self-constraint function, eliminating the need for separate rings or pistons and simplifying the overall device structure.
3Reliability
If rings or pistons are used to maintain vane contact, then sealing is improved, but compactness is reduced due to radial space occupation
Solution Approach 1:
The invention removes the rings or pistons that occupied radial space within the rotor. The sealing function is maintained by the vane's own design, which extends directly to contact the stator profile, eliminating the need for additional radial space-consuming components and improving pump compactness.
4Productivity
If high rotational speeds are used, then productivity is improved, but centrifugal forces increase causing extreme wear
Solution Approach 1:
The invention removes the rings or pistons that amplified and transmitted centrifugal forces to the vanes and stator. Without these intermediate components, the centrifugal forces act directly on the vane-stator contact interface, eliminating the force amplification effect and the resulting extreme wear that limited operational speeds.
Solution Approach 2:
The vane system self-regulates the contact pressure with the stator through its own geometry and the pressure differential across it, rather than having contact pressure amplified by external rings or pistons. This self-service mechanism allows the system to operate at high speeds without the excessive wear that would otherwise result from amplified centrifugal forces.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution significantly reduces wear and failure, allows for higher rotational speeds, and achieves efficient hermetic sealing and volumetric performance with minimal clearance, resulting in a more reliable and compact pumping unit.
Implementation Method 1
the vanes, due to the lack of the action exercised by the centrifugal force and because of the sticking effect with their respective seat in the rotor caused by high oil viscosity, tend to remain stationary
Implementation Method 2
the vanes which should guarantee constant contact with the internal surface of the stator under all working conditions, and therefore ultimately the hermetic sealing between the various pump areas
Data Source
Figure 1~3
Figure 4~5
AI summary
Pumping unit (10) for rotary vane pumps, in particular for oil pumps, comprising a plurality of vanes (21,22,23) and means adapted to activate their movement. The pumping unit (10) comprises a rotor (16) and a stator (12) having a profile (12a) for vane sliding motion. Each vane (21,22,23) is inserted into a respective diametric opening (16b) provided in the rotor (16) so that the rotor (16) rotation generates the motion of the vanes with the ends (21a,22a,23a) of each vane(21,22,23) that remain in constant contact with the internal profile (12a) of the stator (12), thus defining a desmodromic translation movement of the vane (21,22,23) inside the diametric openings 16b) of the rotor (16). The number Np of the vanes is such that Np≥3, these vanes generating a number Nv of compartments (17a) so that Nv=2Np.