Gear Pump Axial Capacity Control via Segmented Side Plates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gear pumps face inefficiencies in capacity adjustment, leading to potential power loss and excessive oil supply due to high fluid pressure requirements for axial movement of side plates, affecting flow rate and discharge pressure.
Innovation Solution
A gear pump design featuring a gear holder with axial biasing and pressing forces, allowing for efficient capacity variation without interfering with oil discharge, utilizing sliding friction on different parts to secure rotation and movement, and an internal flow passage to actuate the pressing force through fluid pressure, reducing component count and manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the discharged fluid pressure is received on the whole back surface of the side plate to exert the pressing force for axial movement, then the gear pump achieves variable capacity through axial movement of gears, but a large amount of discharged fluid is consumed and the pressure can fall to a level that affects the flow rate
Solution Approach 1:
The side plate is segmented into a first side plate and a second side plate that can move independently relative to each other in the axial direction. The pressing force is applied to the first side plate while the second side plate moves with the driven gear, allowing independent control of the pressing force application point and reducing fluid consumption while maintaining variable capacity functionality.
Solution Approach 2:
A pressing force application portion is introduced as an intermediary component that receives the pressing force from the discharged fluid and transmits it to the first side plate. This intermediary mechanism allows the pressing force to be applied more efficiently, reducing the amount of discharged fluid needed to generate the required force while maintaining the ability to vary pump capacity.
2Productivity
If the meshing width of gears is reduced by axial movement to decrease pump capacity at high rotational speeds, then excessive oil supply is prevented, but a large driving force is consumed by the oil pump leading to power loss
Solution Approach 1:
The gear pump implements dynamic capacity adjustment through axial movement of the driven gear and second side plate, allowing the meshing width to vary continuously with rotational speed. This dynamic adaptation enables the pump to match oil supply to actual engine needs, preventing both excessive supply and the power loss associated with high-pressure constant capacity operation.
Solution Approach 2:
The pump capacity is varied by changing the axial position of the second side plate and driven gear, which directly alters the meshing width parameter. This parameter change allows the pump to operate efficiently across different rotational speeds, reducing the driving force required by preventing excessive oil supply while maintaining adequate lubrication.
3Device complexity
If both side plates and driven gear move axially together, then the gear holder structure simplifies, but friction between moving parts increases and operational reliability decreases
Solution Approach 1:
The side plate assembly is segmented into a first side plate and a second side plate that can move independently. The first side plate remains relatively fixed while the second side plate moves axially with the driven gear. This segmentation reduces friction between moving parts since not all components move together, thereby improving operational reliability while maintaining structural simplicity.
4Reliability
If the pressing force is increased to ensure adequate oil supply pressure, then flow rate stability is maintained, but the required fluid pressure for axial movement increases consuming more discharged fluid
Solution Approach 1:
The pressing force application portion acts as an intermediary that efficiently transmits the pressing force from the discharged fluid to the first side plate. This intermediary mechanism improves the force transmission efficiency, allowing adequate pressing force to be generated with less discharged fluid consumption, thereby maintaining flow rate stability without increasing fluid consumption.
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 enhances operational reliability and efficiency by minimizing frictional interference, reducing the required pressing force, and maintaining stable discharge flow rates across varying engine outputs, while reducing manufacturing complexity and costs.
Implementation Method 1
The gear holder is subjected to an axial biasing force from a bias member
Implementation Method 2
subjected also to a pressing force that pushes the gear holder, against said biasing force, to the other side in the axial direction of the support shafts
Implementation Method 3
the gear holder holding the second gear moves in the axial direction of the support shafts
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
An oil pump 1 comprises a drive gear 31, which rotates with a drive shaft 30, a driven gear 61, which meshes with the drive gear and is supported rotatable on a driven shaft 60, and a casing 3 having a pump chamber 2, which accommodates the drive gear and the driven gear. The casing of the gear pump is provided with an intake port 4 and a discharge port 5, which are in fluid communication with the pump chamber 2, so that oil is sucked through the intake port and discharged through the discharge port. A gear holder 110 is provided in the casing such that the gear holder supports the driven gear rotatable and holds both sides of the driven gear while the gear holder itself is being supported axially movable by the driven shaft. The gear holder holding the driven gear moves axially by receiving a biasing force and also a pressing force acting against the biasing force.