Cooling Fan Rotor Support for Railway Dynamo-Electric Machine
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotary electric machines for railway vehicles face challenges in stably fixing the rotor, leading to axial center position displacement, potential damage from stator and rotor contact, and difficulty in securing space for cooling, while also increasing mass and cost due to the need for rotor supporting devices and support receiving units.
Innovation Solution
The design incorporates a stator, rotor with a laminated magnetic steel core, cooling fans with groove-like or hole-like holding portions for bearing attaching and detaching jigs, and a tubular frame with detachable bearing units, allowing for simplified bearing attachment and detachment without relying on frictional support, thus maintaining rotor alignment and enabling efficient cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If rotor supporting devices and support receiving units are provided near the bearing bracket and housings, then the rotor can be supported during bearing maintenance, but it becomes difficult to secure space for cooling the bearings with a cooling fan and increases the mass of the rotary electric machine
Solution Approach 1:
The cooling fan is designed to serve dual functions: it cools the bearings and simultaneously acts as a rotor supporting device. The fan blades extend to form support surfaces that contact the rotor shaft, allowing the fan to support the rotor during bearing maintenance while maintaining its primary cooling function. This eliminates the need for separate rotor supporting devices, reducing mass while enabling bearing maintenance operations.
Solution Approach 2:
The invention merges the cooling fan structure with the rotor support function by extending the fan blades to contact the rotor shaft. This integration combines two previously separate functions (cooling and support) into a single component, thereby reducing the number of parts and overall mass while maintaining both functionalities.
2Ease of operation
If the rotor is supported by frictional force at the tip portions of rotor supporting devices, then the rotor can be held in position, but it is difficult to stably fix the rotor and the axial center position may be displaced
Solution Approach 1:
The invention replaces the friction-based mechanical support system with a geometric constraint system. Instead of relying on friction at tip portions, the fan blades are designed with specific geometries that mechanically constrain the rotor shaft position. This substitution provides more reliable and stable fixation by using geometric interlocking rather than friction, preventing axial center position displacement.
3Ease of operation
If rotor supporting devices are provided to support the rotor, then the rotor can be held during bearing maintenance, but additional structures increase the mass and cost of the rotary electric machine
Solution Approach 1:
The cooling fan is designed to serve dual functions: it cools the bearings and simultaneously acts as a rotor supporting device. The fan blades extend to form support surfaces that contact the rotor shaft, allowing the fan to support the rotor during bearing maintenance while maintaining its primary cooling function. This eliminates the need for separate rotor supporting devices, reducing mass while enabling bearing maintenance operations.
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 solution simplifies the operation of attaching and detaching bearings, prevents rotor-stator contact, secures space for cooling, and reduces the mass and cost of the rotary electric machine by eliminating the need for additional support structures, ensuring stable rotor fixation and efficient maintenance.
Implementation Method 1
a cooling fan, which is attached to the core holder and which has blade portions extending in a radial direction of the rotor
Implementation Method 2
a bearing unit that is detachably attached to the rotor shaft supporting unit and that rotatably supports the rotor shaft
Data Source
Figure 1
Figure 2
Figure 3(a)~3(c)
AI summary
A rotary electric machine includes a stator core 3; a rotor 7 that includes a laminated core 4, core holders 5 and 11, and cooling fans 60 and 70; a frame that includes a tubular unit 9 that encloses the stator core 3 and the rotor 7, and a first bracket 1 and a second bracket 2 that extend in a direction of a rotor shaft 6 and supports the rotor shaft 6; and cartridges 29 and 49 that are detachably attached to the first bracket 1 and the second bracket 2 and rotatably supports the rotor shaft 6, wherein groove-like or hole-like holding portions 64 and 74, which hold end portions of bearing attaching and detaching jigs 20a and 20b inserted through the first bracket 1 and the second bracket 2, are provided in the cooling fans 60 and 70.