Motor Rotor Cooling via Segmented Axial Holes
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Solution Overview
Problem
In large-capacity compression refrigeration systems with simply supported rotor shafts, conventional motor cooling methods fail to effectively cool the motor as the rotor is no longer easily accessible, preventing efficient heat absorption by liquid refrigerant.
Innovation Solution
A motor cooling system with rotor axial and radial holes, a refrigerant dam, and a spray bar with an angled chute ensures efficient cooling by creating a flow path for liquid refrigerant to reach and cool the rotor core, even in simply supported compressor systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If liquid refrigerant is sprayed into the unsupported end of the motor, then motor cooling is effective, but this method cannot be applied to simply supported rotor shaft configurations where the rotor is not easily accessible
Solution Approach 1:
The rotor is segmented with multiple axial holes and radial holes to create internal cooling passages. This segmentation allows refrigerant to be distributed throughout the rotor core, enabling effective cooling without requiring direct spray access to the rotor exterior.
Solution Approach 2:
A refrigerant dam is introduced as an intermediary component between the spray bar and the rotor. The dam redirects and channels the refrigerant flow through the rotor shaft and into the rotor core via aligned axial holes, mediating the cooling process when direct rotor access is limited.
2Temperature
If conventional motor cooling methods are used in simply supported systems, then the rotor structure remains simple, but motor cooling effectiveness is insufficient
Solution Approach 1:
The rotor structure is divided into multiple segments with axial holes and radial holes creating a network of cooling passages. This segmentation enables effective heat removal from the rotor core while maintaining a relatively simple overall rotor design that integrates with the existing simply supported shaft configuration.
Solution Approach 2:
The cooling passages are nested within the existing rotor structure. Axial holes are drilled through the rotor length, and radial holes extend from these axial holes to create a nested network of cooling channels that utilize the rotor's existing geometry without requiring major structural modifications.
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 provides effective motor cooling without compromising the rotor's size or weight, ensuring direct contact heat exchange and adequate cooling of hard-to-reach areas within the motor.
Implementation Method 1
The refrigerant is injected into the motor housing where it absorbs motor heat and rapidly evaporates or flashes into gaseous form, thus cooling the motor
Implementation Method 2
The refrigerant is injected into the motor housing where it absorbs motor heat and rapidly evaporates or flashes into gaseous form
Implementation Method 3
The refrigerant travels through axial and radial holes cooling the rotor
Implementation Method 4
A cooling medium is supplied to the spray bar. The elongated chute is arranged at an angle such that a free end of the elongated chute is adjacent an interface between the refrigerant dam and the rotor shaft
Data Source
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AI summary
A motor cooling system for a simply supported compressor includes a rotor shaft having a first end and a second end. The rotor shaft includes an axial bore and a plurality of shaft radial holes extending from a first end of the axial bore. A cooling medium is supplied to the axial bore and includes a rotor coupled to the rotor shaft and having a plurality of rotor axial holes and a plurality of rotor radial holes. The plurality of rotor radial holes extends from the plurality of rotor axial holes. A refrigerant dam is arranged adjacent a first end of the rotor and includes a plurality of dam axial holes fluidly coupled to an interior cavity. The dam axial holes align with the rotor axial holes and the interior cavity aligns with the shaft radial holes to form a flow path between the rotor shaft and the rotor.