Electric Motor Pump Cooling via Annular Gap Deflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric-motor-driven liquid pumps for automotive transmission applications face challenges in achieving a compact and lightweight design while ensuring reliable operation over a wide temperature range, with inadequate heat dissipation and significant axial installation space requirements.
Innovation Solution
The design features a suction inlet arranged radially inward within the annular gap between the rotor and stator, with a partition wall for cooling, and a bypass connection to manage viscosity at low temperatures, allowing for efficient heat dissipation and reduced axial space, using a plastic injection-molded enclosure for the stator windings and a cup-shaped rotor for compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the pump is made more compact to reduce installation space, then the axial installation space is reduced, but heat dissipation from the electric motor becomes inadequate
Solution Approach 1:
The patent merges the cooling function with the pump's operational liquid flow. The liquid to be pumped serves dual purposes: it is both the working fluid for pressure generation and the cooling medium for the electric motor. The motor is positioned within the liquid flow path, allowing the liquid to directly cool the motor during normal pump operation, thereby integrating cooling into the pump's compact structure without requiring separate cooling systems or increasing axial space.
2Volume of moving object
If the pump construction is made more compact, then installation space is reduced, but reliable functioning over a large temperature range becomes more difficult
Solution Approach 1:
The patent combines the motor cooling function with the pump's liquid flow system. The liquid circulating through the pump simultaneously cools the motor, ensuring reliable operation across temperature ranges without requiring additional cooling components that would increase size.
Solution Approach 2:
The patent utilizes changes in liquid viscosity and flow characteristics across temperature ranges to maintain effective cooling. The liquid flow rate and cooling efficiency are designed to adapt to temperature variations, ensuring the motor remains within operational temperature limits regardless of ambient conditions.
3Weight of moving object
If the pump is made lighter using plastic materials, then weight is reduced for lower fuel consumption, but heat dissipation capability is reduced
Solution Approach 1:
The patent merges the cooling function with the operational liquid flow, eliminating the need for heavy metal cooling components. The liquid serves as both the working fluid and cooling medium, allowing the use of lightweight plastic materials for the pump housing while maintaining adequate heat dissipation through the liquid-cooled motor design.
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 configuration enables optimized cooling, weight reduction, and a compact form factor suitable for direct installation within transmission housings, with improved flow efficiency and heat dissipation, addressing the challenges of temperature variability and space constraints.
Implementation Method 1
a liquid inducted by the suction inlet of the conveying device via the suction connection of the housing is constrainedly guided partly by way of the annular gap between rotor and stator and undergoes deflection at the partition wall of the housing, with cooling the wall
Implementation Method 2
an electric motor with the assistance of electrical energy from the on-board power source or battery of the motor vehicle
Data Source
AI summary
A liquid pump has a housing with a suction connection, a pressure connection and a electric motor for rotationally driving a conveying device that has a suction inlet and pressure outlet which communicate with the suction connection and the pressure connection respectively. An electronic power unit for the electric motor is adjacent to the motor and extends transversely to the axis of rotation and is on the rear side of the partition wall of the housing. The suction inlet is arranged at a height smaller than an inner radius of an annular gap between the stator and rotor, whereas a rotor passage extends at a constant height, so that a liquid inducted by way of the suction connection is guided in part via the annular gap and undergoes a deflection at the partition wall, cooling the latter before it passes through the rotor passage to the suction inlet.