Automotive Electric Liquid Pump Radial Slide Bearing Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional automotive electric liquid pumps are not compact enough due to the axial length required for separate roller or slide bearings, which affects hydraulic efficiency and stability.
Innovation Solution
The pump employs a radial slide bearing arrangement with a cylindrical bearing ring and a static bearing ring, separated by a small radial bearing gap, allowing lubrication with the pumped liquid and reducing axial length by eliminating bearings outside the motor rotor, along with a continuous central cooling bore and axial slide bearing for enhanced stability and cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate roller or slide bearings are arranged axially outside the motor rotor, then the bearing supports the rotor shaft reliably, but the axial length of the pump increases
Solution Approach 1:
The bearing function is merged with the motor rotor structure. The bearing rings are arranged within the axial extension of the motor rotor, integrating the bearing support function into the motor rotor itself rather than placing separate bearings axially outside it. This integration maintains reliable rotor shaft support while reducing the overall axial length of the pump.
Solution Approach 2:
The bearing arrangement transitions from an axial configuration (bearings outside the motor rotor along the axial direction) to a radial configuration (bearing rings within the axial extension of the motor rotor). This dimensional change allows the bearing function to be achieved without increasing the axial length, as the bearing support is provided within the radial space of the motor rotor.
2Productivity
If the radial bearing gap is made small to improve hydraulic efficiency, then the pump hydraulic efficiency increases, but the lubrication of the bearing becomes insufficient
Solution Approach 1:
The liquid in the pump serves multiple functions simultaneously. It acts as both the pumped medium for hydraulic work and as the lubricant for the bearing. The liquid is fed into the bearing gap to provide lubrication, while maintaining a small gap for high hydraulic efficiency. This multi-functionality allows the same liquid to fulfill both hydraulic and lubrication requirements without compromise.
Solution Approach 2:
The pump system lubricates its own bearing using the liquid it pumps. The liquid that is being pumped through the system is diverted to lubricate the bearing, eliminating the need for a separate lubrication system. The bearing gap is designed to receive liquid from the pump's own flow, creating a self-lubricating system that maintains both small gap for efficiency and sufficient lubrication.
3Length of moving object
If the axial length of the pump is reduced by avoiding bearings outside the motor rotor, then the pump becomes more compact, but the stability against tilting of the rotor arrangement may be compromised
Solution Approach 1:
The bearing support function is merged with the motor rotor structure, with bearing rings arranged within the axial extension of the motor rotor. This integration provides stable support against tilting while maintaining a compact axial length, as the bearing support is distributed within the motor rotor's axial boundaries rather than extending beyond them.
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 results in a more compact, high-efficiency pump with reduced friction and axial length, ensuring stable operation and efficient lubrication while maintaining hydraulic efficiency and cooling functionality.
Implementation Method 1
The radial bearing gap G between the static bearing ring and the rotor bearing ring allows a lubrication of the bearing within the bearing gap G with the coolant liquid or with the lubrication liquid
Implementation Method 2
The liquid pumped by the pump rotor is pushed through the cooling bore from the pump rotor end of the shaft to the other axial end of the shaft, from where the liquid is radially flowing outwardly and axially flowing back through the bearing gap back to the pump section
Data Source
Figure 1
AI summary
The invention refers to an automotive electric liquid pump (10) with a pump rotor (21) and a motor rotor (32) with the motor rotor (32) rotating in a separation can (50), wherein the radial outside of the motor rotor (32) is provided with a cylindrical bearing ring (34,36) and the radial inside of the separation can (50) is provided with a corresponding static bearing ring (54, 56), and the rotor bearing ring (34, 36) and the static bearing ring (54, 56) together define a radial slide bearing (61, 62).