Contra-rotating Axial Blower Stator Cooling via Frame Through-holes
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Solution Overview
Problem
Counter-rotating axial-flow fans face challenges in managing increased motor size and current, leading to elevated stator temperatures within motors, which restrict the full utilization of motor capability due to heat accumulation.
Innovation Solution
The design incorporates through-holes in the motor support frame to direct air from the first impeller's internal space to the second impeller's space, facilitating direct cooling of both motors' stators and enhancing heat dissipation through strategically positioned and sized through-holes and heat-conductive bearing holders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the impeller size is increased to improve cooling performance, then the motor current is increased, but the heat generated from the stator accumulates in the motor internal space causing temperature to exceed allowable limits
Solution Approach 1:
The motor internal space is segmented into multiple cooling zones through the introduction of partition walls and multiple cooling holes. The partition wall divides the internal space into a first cooling space and a second cooling space, allowing independent temperature control and heat dissipation pathways for different motor components (stator and rotor), thereby preventing heat accumulation while maintaining high motor current for improved cooling performance
Solution Approach 2:
Cooling air is introduced as an intermediary substance through the cooling holes in the partition wall to transfer heat from the motor internal components to the external environment. The cooling air flows through the first and second cooling spaces, absorbing heat from the stator and rotor respectively, and is then discharged through the discharge hole, effectively reducing motor internal temperature while allowing higher motor current operation
2Temperature
If vent holes are formed in the rotor to cool the motor, then some heat dissipation is achieved, but heat generated from the stator still accumulates in the motor internal space
Solution Approach 1:
The cooling system is segmented into multiple independent cooling pathways: cooling holes in the partition wall for stator cooling, vent holes in the rotor for rotor cooling, and separate discharge holes. This segmentation ensures that both stator and rotor are cooled effectively, preventing heat accumulation and allowing the motor to operate at full capability without temperature exceeding allowable limits
Solution Approach 2:
The partition wall serves multiple functions: it acts as a structural support element, creates cooling spaces, provides mounting surfaces for cooling holes, and functions as a heat dissipation structure itself. This multi-functionality allows comprehensive cooling of both stator and rotor while maintaining motor structural integrity, enabling full motor capability utilization
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 effectively reduces internal motor temperatures, allowing for the optimal operation of both motors by efficiently cooling the stators and preventing overheating.
Implementation Method 1
the first impeller and the rotor of the first motor are configured to introduce air sucked through the suction port into an internal space of the first motor
Implementation Method 2
one or more through-holes which penetrate the support frame body in an extending direction of the axial line are formed in the support frame body. Positions and a total cross sectional area of the one or more through-holes are defined to introduce or guide the air, which has been introduced into the internal space of the first motor, into the internal space of the second motor
Implementation Method 3
the stator of the first motor and the stator of the second motor can directly be cooled by the air flow as described above
Data Source
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AI summary
A counter-rotating axial-flow fan is provided that is capable of increasing effect of cooling a stator. One or more through-holes 83 penetrating support frame bodies (21, 75) in the axial direction are formed in support frame bodies 21 and 75. One or more vent holes 57a for introducing air, sucked from a suction port 19, into a cup-like member 51 are formed in a bottom wall portion 57 of a cup-like member 51 of a first impeller 9. One or more vent holes 111a for discharging air, introduced into an internal space of a second motor 61, to the outside are formed in a bottom wall portion 111 of a cup-like member 105 of a second impeller 63.