Variable-capacity Oil Pump Stopper Positioning
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Solution Overview
Problem
Conventional variable displacement oil pumps suffer from reduced suction performance due to the arm portion of the cam ring overlapping the suction portion, increasing suction resistance.
Innovation Solution
The stopper portion is positioned to not overlap the suction portion in the circumferential direction of the drive shaft, reducing suction resistance and improving suction performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the arm portion of the cam ring is arranged to overlap the suction portion, then the stopper portion can be positioned to limit cam ring movement, but suction resistance increases and suction performance deteriorates
Solution Approach 1:
The stopper portion is repositioned from a radial arrangement (overlapping the suction portion) to a tangential arrangement (not overlapping the suction portion). This dimensional change in position allows the stopper to maintain its function of limiting cam ring movement while avoiding interference with the suction flow path, thereby reducing suction resistance.
2Object-affected harmful factors
If the stopper portion is positioned to not overlap the suction portion, then suction resistance is reduced, but the structural arrangement becomes more complex
Solution Approach 1:
The stopper portion is designed with a specific local geometry that allows it to be positioned tangentially to the cam ring. This local quality adjustment enables the stopper to achieve the optimal position for reducing suction resistance while maintaining a relatively simple overall structure, avoiding the need for complex reconfiguration of the entire cam ring assembly.
Data Source
AI summary
In a variable displacement oil pump (VP1) according to the present invention, a stopper portion (45) that can come into contact with a cam ring contact portion (112e) provided at a pump accommodating portion (110) is provided at a position that does not overlap a first suction port (114), a second suction port (124) and an inlet (124a), which correspond to a suction portion, in a circumferential direction of rotation of a drive shaft (2) on a rotation center (Z). Therefore, there is no risk that flow of oil sucked into pump chambers (30) located in a suction region through the first suction port (114), the second suction port (124) and the inlet (124a) will be interrupted by the stopper portion (45), thereby improving a suction performance of the pump.