Vane Pump Rotor Axial Pressing and Sealing Design
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Solution Overview
Problem
The existing vane pump design suffers from radial shift of the rotor's center axis relative to the drive shaft, leading to whirling motion and increased oil leakage due to annular clearance, which deteriorates pump efficiency and sealing performance.
Innovation Solution
The rotor is modified with a cylindrical portion and slide contact surfaces, featuring annular grooves with varying pressure receiving areas to axially press the rotor, enhancing sealing by increasing the pressure receiving area on one side and reducing leakage through the annular clearance between the drive shaft and rotor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a large annular clearance is provided between the drive shaft and rotor to prevent interference with the outside circumferential surface of the drive shaft, then the rotor can rotate freely without interference, but oil leakage increases through the annular clearance, deteriorating pump efficiency
Solution Approach 1:
A thrust bearing is introduced as an intermediary component between the rotor and housing to control axial movement. The thrust bearing maintains optimal clearance between the drive shaft and rotor, preventing both interference and excessive leakage, thus resolving the contradiction between rotation freedom and pump efficiency
Solution Approach 2:
The clearance between the drive shaft and rotor is precisely controlled by selecting appropriate thrust bearing models and adjusting axial positions. This parameter optimization ensures the clearance is large enough to prevent interference but small enough to minimize oil leakage, balancing rotation freedom with pump efficiency
2Device complexity
If the rotor is not axially constrained, then the structure remains simple and assembly is easy, but radial shift of the rotor center axis occurs, causing whirling motion and increased oil leakage
Solution Approach 1:
The thrust bearing serves as a mediator that provides axial constraint to the rotor through controlled contact. This constraint prevents radial shift and whirling motion while maintaining a simple overall structure, thus improving reliability without significantly increasing device complexity
Solution Approach 2:
The thrust bearing automatically adjusts to maintain optimal axial position of the rotor, preventing radial shift and ensuring proper clearance maintenance. This self-adjusting mechanism improves sealing performance and reliability while requiring minimal additional structural complexity
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 design improves the sealing performance by reducing oil leakage and maintaining pump efficiency by axially pressing the rotor, preventing undesired shifts and maintaining the intended eccentricity, thus optimizing the pump's operation and reducing power loss.
Implementation Method 1
the slide contact portion of the rotor includes a slide contact surface abutting slidably on an inside wall surface of a second side wall of the housing
Implementation Method 2
A pressure receiving area of one of the first and second annular grooves is set greater than a pressure receiving area of the other of the first and second annular grooves
Data Source
AI summary
A vane pump includes a rotor including a first annular groove and a second annular groove. The rotor further includes a cylindrical portion projecting axially from a radial inner side of the first annular groove and fitting over a drive shaft, and a slide contact portion formed on a radial inner side of the second annular groove. The cylindrical portion is slidably received in a bearing hole formed in a first side wall of a housing, whereas the slide contact portion abuts slidably on an inside wall surface of a second side wall of the housing. There is further formed, in the first annular groove, a recessed portion making a pressure receiving area of one of the first and second annular grooves greater than a pressure receiving area of the other of the first and second annular grooves.