Rotating Electric Machine Cooling Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotating electric machines for industrial vehicles face increased axial length due to cooling structures and rotational speed detection gears, which complicates their design and increases heat generation, making them less efficient and more cumbersome.
Innovation Solution
A rotating electric machine design featuring a rotational speed detection gear with gear teeth on the shaft between the rotor and a bearing, integrated with an air-cooling system that includes air intake and outlet ports and recessed passages in the housing to minimize axial length while maintaining effective cooling, allowing for the installation of a brake device without additional projections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a cooling fan is mounted on the shaft outside the motor housing, then cooling performance is improved, but the axial length of the motor is increased
Solution Approach 1:
The cooling fan is merged with the rotational speed detection gear by forming the fan blades on the outer peripheral surface of the detection gear body. This integration allows the cooling function to be achieved without adding separate cooling components that would increase axial length, as the detection gear itself serves dual purposes: speed detection and air cooling.
Solution Approach 2:
The rotational speed detection gear is given multiple functions: it detects rotational speed through its gear teeth interacting with the sensor, and simultaneously serves as a cooling fan by having fan blades formed on its outer peripheral surface. This multi-functionality eliminates the need for separate cooling components, maintaining compact axial dimensions while providing effective cooling.
2Difficulty of detecting and measuring
If a rotational speed detection gear is added to the cooling structure, then speed detection capability is improved, but the axial length is further increased
Solution Approach 1:
The cooling fan and rotational speed detection gear are merged into a single integrated component. The detection gear's gear teeth engage with a detection sensor for speed detection, while its outer peripheral surface incorporates fan blades for cooling. This merging eliminates the need for separate cooling and detection components, preventing additional axial length increase.
Solution Approach 2:
The detection gear serves universal functions by simultaneously enabling speed detection through its gear teeth and providing cooling through its fan blades. This multi-functional design allows the system to achieve both speed detection capability and cooling performance without adding axial length.
3Length of moving object
If the axial length is reduced for compactness, then device size is improved, but cooling performance and brake device installation are compromised
Solution Approach 1:
The cooling function is merged into the detection gear structure itself, with fan blades formed on its outer peripheral surface. This integration allows cooling performance to be maintained within the compact axial length, as no additional cooling components extending axially are required.
Solution Approach 2:
Instead of extending the cooling structure axially, the fan blades are arranged radially on the outer peripheral surface of the detection gear. This dimensional change allows cooling air to be drawn in radially and discharged axially through dedicated ports, maintaining compact axial length while preserving cooling effectiveness.
4Length of moving object
If the axial length is reduced for compactness, then device size is improved, but brake device installation becomes difficult
Solution Approach 1:
The cooling fan and detection gear are merged into a single component, eliminating the need for additional axial space that would be required for separate cooling structures. This integration creates available axial space for mounting the brake device while maintaining overall compact dimensions.
Solution Approach 2:
The cooling air flow path is reconfigured to draw air radially inward through intake ports and discharge it axially through outlet ports positioned on the housing. This dimensional rearrangement of the cooling system allows brake device installation on the end surface without interfering with cooling functionality, maintaining both compactness and adaptability.
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 the axial length of the rotating electric machine while maintaining cooling performance and enabling the installation of a brake device, thus improving efficiency and compactness.
Implementation Method 1
A rotational speed detection gear is mounted on the shaft for rotation therewith at a position between the rotor and one of the bearings and in a vicinity of the bearing, and the rotational speed detection gear has a plurality of gear teeth at an outer circumference thereof. A rotational speed detector is provided at a position in the housing so as to face the gear teeth of the rotational speed detection gear.
Implementation Method 2
A rotating member for generating a flow of air is disposed in the housing
Implementation Method 3
the housing includes a cylindrical peripheral wall and opposite end walls. One of the end walls is a gear-side end wall that is adjacent to the rotational speed detection gear, and the gear-side end wall has at a position adjacent to the shaft an air intake port that provides communication between inside and outside of the housing.
Data Source
AI summary
The rotating electric machine includes a housing, a pair of bearings that is fixed by the housing, a shaft supported at opposite ends thereof by the respective bearings, a rotor mounted on the shaft for rotation therewith, and a stator disposed in such a manner as to surround the rotor. A rotational speed detection gear is mounted on the shaft for rotation therewith at a position between the rotor and one of the bearings and in a vicinity of the bearing, and the rotational speed detection gear has a plurality of gear teeth at an outer circumference thereof. A rotational speed detector is provided at a position in the housing so as to face the gear teeth of the rotational speed detection gear. A rotating member for generating a flow of air is disposed in the housing.