Vehicle Drive Device Cooling Guide Portion
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Solution Overview
Problem
Existing vehicle drive devices with coaxially arranged rotary electric machines face challenges in size reduction and cooling efficiency, as high-temperature refrigerant from an upper machine can deteriorate the cooling performance of a lower machine.
Innovation Solution
A vehicle drive device design featuring a guide portion within the case to prevent cooled refrigerant from flowing to the second rotary electric machine, with separate cooling paths and return ports to enhance cooling efficiency and prevent heat transfer between machines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If two rotary electric machines are vertically arranged on different axes, then the axial length can be reduced, but the cooling performance deteriorates because high-temperature refrigerant from the upper machine flows to the lower machine
Solution Approach 1:
The housing is divided into an upper housing and a lower housing with a partition wall between them. This segmentation prevents the refrigerant that has cooled the first rotary electric machine from flowing into the second rotary electric machine, thereby maintaining separate cooling zones and preventing heat transfer between machines while preserving the compact vertical arrangement
Solution Approach 2:
A guide portion is introduced as an intermediary structure that directs the refrigerant flow. The guide portion includes a guide surface that guides the refrigerant from the first rotary electric machine toward the refrigerant introduction port, ensuring controlled flow paths and preventing direct flow from the first machine to the second machine
2Device complexity
If two rotary electric machines are coaxially arranged, then the structure is simplified, but the axial length cannot be shortened
Solution Approach 1:
The patent transitions from coaxial arrangement (one-dimensional alignment) to vertical arrangement on different axes (three-dimensional spatial distribution). This dimensional change allows the rotary electric machines to be positioned at different vertical levels with overlapping horizontal projections, reducing the axial length while maintaining structural manageability through the housing partition
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 solution improves cooling performance by isolating the refrigerant flow between machines, preventing heat transfer and allowing for efficient refrigerant recovery, thus enhancing the overall cooling efficiency and reducing the axial length of the device.
Implementation Method 1
The first rotary electric machine and the second rotary electric machine are cooled by a refrigerant flowing inside the case
Implementation Method 2
The first rotary electric machine and the second rotary electric machine are cooled by a refrigerant flowing inside the case
Data Source
AI summary
A vehicle drive device includes: a first rotary electric machine; a second rotary electric machine that is arranged below the first rotary electric machine; and a case having a rotary electric machine housing portion that houses the first rotary electric machine and the second rotary electric machine. The first rotary electric machine and the second rotary electric machine are cooled by a refrigerant flowing inside the case, and in the rotary electric machine housing portion, a guide portion that prevents the refrigerant, which has cooled the first rotary electric machine, from being applied to the second rotary electric machine is provided.