Conical Motor Chamber Pump Unit for Compact High-Capacity Hydraulics
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Solution Overview
Problem
Existing compact pump units for hydraulic automotive actuating systems, such as those used in convertible roof systems and vehicle wheel suspensions, often fall short in providing sufficient pump capacity while maintaining compactness, limiting their application in various fields like marine, medical, and civil sectors.
Innovation Solution
A pump unit design featuring a diverging clearance between the motor rotor and motor housing, which reduces hydraulic friction by allowing hydraulic fluid to flow from a smaller to a larger diameter, and includes a fluid outlet at the larger diameter to discharge fluid, thereby enhancing power transfer and allowing for a more compact configuration with increased pump capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the pump unit is made more compact, then the build-in space is reduced, but the pump capacity becomes insufficient
Solution Approach 1:
The clearance between the motor rotor and motor housing is changed from a parallel configuration to a diverging (conical) configuration. This parameter change allows the clearance volume to vary along the axial direction, creating a pressure difference that forces hydraulic fluid toward the fluid outlet. This resolves the contradiction by enabling efficient fluid discharge in a more compact motor chamber design, thereby maintaining pump capacity while reducing build-in space.
2Reliability
If hydraulic fluid is retained in the motor chamber, then lubrication is maintained, but hydraulic friction increases reducing power transfer efficiency
Solution Approach 1:
Hydraulic fluid is extracted from the motor chamber through a specifically designed diverging clearance and fluid outlet configuration. The clearance diverges from small diameter to large diameter along the axial direction, creating a pressure difference that actively forces hydraulic fluid toward the outlet. This extracts excess hydraulic fluid that causes friction while maintaining sufficient fluid for lubrication, thereby reducing energy loss and improving power transfer efficiency.
Solution Approach 2:
The invention utilizes hydraulic pressure differences created by the diverging clearance geometry to control fluid flow. The pressure difference between the small diameter and large diameter ends of the clearance forces hydraulic fluid toward the fluid outlet, enabling passive fluid management that reduces friction while maintaining lubrication through hydraulic principles.
3Volume of moving object
If the clearance between motor rotor and motor housing is reduced, then compactness is improved, but hydraulic friction increases
Solution Approach 1:
The clearance geometry is made non-uniform along the axial direction, with the clearance width varying from small at one end to large at the other end. This local quality variation creates a pressure gradient that actively manages hydraulic fluid flow, forcing fluid toward the outlet while maintaining a compact overall motor chamber volume. The local geometric modification resolves the contradiction between compactness and friction reduction.
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 reduces hydraulic friction, increasing the available power for the pump unit, enabling a smaller electric motor to achieve the same pump capacity, resulting in a more compact and efficient hydraulic actuating system.
Implementation Method 1
Seen in the axial direction, the diverging shape of the clearance causes a pressure difference between a position of the small diameter and a position of the large diameter of the clearance. Due to the diverging shape of the clearance and the presence of the fluid outlet, hydraulic fluid in the motor chamber is forced to flow from the small diameter to the large diameter of the clearance.
Data Source
AI summary
Pump unit (10) comprising an electrically driven hydraulic pump (4) for pressurising a hydraulic actuating system. The pump unit (10) comprises a hydraulic pump (4) in pump chamber (110) of a pump housing (11). The pump (4) is driven by an electric motor (3) which includes a motor rotor body (310) and an assembly of field coils (32) and magnets (33). A clearance (C) is provided around the motor rotor body (310) which is diverging in the axial direction from a small to a large diameter, such that a rotation of the motor rotor body (310) forces hydraulic fluid to flow towards the larger diameter. The fluid outlet (122) at the larger diameter of the clearance allows an exit of the hydraulic fluid, such that a fluid flow is generated which reduces hydraulic friction inside the pump unit to render an increase in pump capacity.