Variable Capacity Pump Dual Spring Equilibrium Control
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Solution Overview
Problem
Conventional variable capacity vane pumps operate at a single equilibrium pressure, which is a compromise for the expected engine operating range, leading to unnecessary energy wastage at lower speeds due to over-capacity operation.
Innovation Solution
A variable capacity vane pump design featuring a moveable control ring with a primary and secondary return spring system, allowing operation at multiple equilibrium pressures by adjusting the volumetric capacity based on fluid pressure and spring forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a single equilibrium pressure is used for the pump, then the pump structure remains simple, but the pump operates at higher capacity than necessary at lower speeds, wasting energy
Solution Approach 1:
The return spring is divided into multiple segments (first return spring segment and second return spring segment) that engage with different portions of the control ring. Each segment provides a different biasing force, enabling the pump to operate at multiple equilibrium pressures corresponding to different engine speed ranges, thus improving energy efficiency without excessive complexity
Solution Approach 2:
The pump control system transitions from a static single-pressure equilibrium to a dynamic multi-pressure equilibrium system. The control ring can move between different equilibrium positions depending on the engagement of different spring segments, allowing the pump to dynamically adjust its operating pressure to match engine speed requirements
2Reliability
If the equilibrium pressure is selected for worst case (high operating speed) conditions, then engine protection is ensured, but the pump operates at higher capacity than necessary at lower speeds, wasting energy
Solution Approach 1:
The return spring is divided into multiple segments (first return spring segment and second return spring segment) that engage with different portions of the control ring. Each segment provides a different biasing force, enabling the pump to operate at multiple equilibrium pressures corresponding to different engine speed ranges, thus improving energy efficiency without excessive complexity
Solution Approach 2:
The system changes the equilibrium pressure parameter based on operating conditions. By using multiple spring segments with different biasing forces, the pump can switch between different pressure levels (e.g., 40-50 psi at high speed, lower at low speed), optimizing both engine protection and energy efficiency
3Use of energy by moving object
If dual return springs are used to enable multiple equilibrium pressures, then energy efficiency is improved, but the pump structure becomes more complex
Solution Approach 1:
The return spring is divided into multiple segments (first return spring segment and second return spring segment) that engage with different portions of the control ring. Each segment provides a different biasing force, enabling the pump to operate at multiple equilibrium pressures corresponding to different engine speed ranges, thus improving energy efficiency without excessive complexity
Solution Approach 2:
Multiple spring segments are combined into a single integrated return spring assembly that works together with the control ring. This merging approach achieves multi-pressure capability while maintaining a relatively compact and unified structure, rather than using completely separate spring systems
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
Enables efficient operation at multiple equilibrium pressures, optimizing energy use and reducing wear by adjusting capacity according to operating conditions, thereby minimizing energy wastage across varying engine speeds.
Implementation Method 1
A primary return spring acts between control ring and the casing to bias the control ring towards a position of maximum volumetric capacity. The primary return spring acts against the force of the control chamber to establish a first equilibrium pressure.
Implementation Method 2
A secondary return spring is mounted in the casing and is configured to engage the control ring after the control ring has moved a predetermined amount. The secondary return spring biases the control ring towards a position of maximum volumetric capacity. The secondary return spring acts against the force of the control chamber to establish a second equilibrium pressure.
Implementation Method 3
The control chamber is operable to receive pressurized fluid to create a force to move the control ring to reduce the volumetric capacity of the pump.
Data Source
AI summary
A variable capacity vane pump has a pump control ring that is moveable to alter the capacity of the pump. A control chamber is formed between the pump casing and the control ring. The control chamber is operable to receive pressurized fluid to create a force to move the control ring to reduce the volumetric capacity of the pump. A primary return spring acts between control ring and the casing to bias the control ring towards a position of maximum volumetric capacity. A secondary return spring is mounted in the casing and is configured to engage the control ring after the control ring has moved a predetermined amount. The secondary return spring biases the control ring towards a position of maximum volumetric capacity. The secondary return spring acts against the force of the control chamber to establish a second equilibrium pressure.