Two-Stage Electric Pump with Integrated Motor and Nested Rotors
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Solution Overview
Problem
Existing electric oil pumps for hybrid electric vehicles are inefficient and costly due to separate manufacturing of pumps, motors, and inverters, and the complexity of two-stage pumps increases component count and volume, leading to high manufacturing costs.
Innovation Solution
A two-stage electric pump design where a high-pressure pump and a low-pressure pump share a common shaft and motor unit, with internal and external rotors configured to reduce power consumption and simplify the structure, integrating the motor and pump housings to minimize components and manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pumps, motors, and inverters are manufactured separately and fastened by bolts, then each component can be independently optimized, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent integrates the motor and pump into a single unified structure where the motor shaft is directly coupled to the pump rotor, eliminating the need for separate mounting brackets, bolts, and coupling mechanisms. This merging reduces assembly complexity while maintaining the ability to independently optimize motor and pump components during the design phase.
2Adaptability or versatility
If a two-stage pump is designed with completely separated pumps, then high-pressure and low-pressure fluid supply is achieved, but the number of components and volume increase
Solution Approach 1:
The patent employs a nested configuration where the low-pressure pump rotor is positioned inside the high-pressure pump rotor, sharing a common motor shaft. This nesting approach enables two-stage pressure functionality while significantly reducing the number of components and overall volume compared to completely separated pump designs.
Solution Approach 2:
The common motor shaft serves multiple functions by simultaneously driving both the low-pressure pump rotor and the high-pressure pump rotor. This multi-functionality reduces the need for separate drive mechanisms, thereby decreasing component count while maintaining adaptability for both pressure stages.
3Reliability
If separate cables are used to connect the inverter to the motor and pump, then electrical connections are established, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent integrates the inverter directly into the motor assembly, eliminating the need for separate external cables and connectors. This merging of electrical components reduces manufacturing cost and assembly complexity while ensuring reliable electrical connections between the inverter, motor, and pump system.
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
The design reduces power consumption, simplifies the configuration, and decreases the number of components and manufacturing costs, resulting in a more compact and efficient electric pump.
Implementation Method 1
a rotor core 112 having a three-phase coil 1121 inserted therein and generating a rotating magnetic field to induce a current, thereby rotating the rotor core 112
Data Source
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AI summary
provided is an electric pump including a motor unit including a stator, a rotor core disposed inside the stator and a shaft coupled to the rotor core; a first pump unit and a second pump unit which are coupled using the shaft as a coaxial axis; a first housing in which a motor housing receiving the motor unit and a pump housing including a first pump accommodating part are integrally formed, the first pump unit being inserted in the first pump accommodating part; a second housing coupled to the first housing to cover the first pump accommodating part and including a second pump accommodating part in which the second pump unit is inserted; and a cover unit coupled to the second housing to cover the second pump accommodating part.