Shaft Seal Device for Rotating Electrical Machine
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Solution Overview
Problem
Existing shaft seal devices for rotating electrical machines, particularly those using hydrogen gas as a cooling medium, face issues with excessive oil consumption and temperature-related damage due to air bubbles in the seal oil, requiring large installation spaces for vacuum tanks and pumps to degas the oil.
Innovation Solution
A shaft seal device with a degassing pump, pressure regulating valve, and differential pressure control valve is used to efficiently degas the seal oil, eliminating the need for vacuum tanks and pumps, thereby reducing the overall size of the machine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vacuum tank and vacuum pump are used to degas seal oil, then air bubbles are expelled from the seal oil, but the installation space becomes large
Solution Approach 1:
The patent combines the vacuum pump and vacuum tank into an integrated unit where the pump is positioned inside the tank. This merging eliminates the need for separate vacuum generation equipment and large vacuum chambers, significantly reducing installation space while maintaining effective degassing functionality through the pump's direct action on the seal oil within the tank
Solution Approach 2:
The vacuum pump is nested within the vacuum tank structure, with the pump body positioned inside the tank's interior space. This nesting arrangement allows the pump to directly process seal oil within the tank while utilizing the tank's own space, eliminating the need for external vacuum equipment and reducing overall system footprint
2Reliability
If the seal oil is sprayed on the inside of a vacuum tank for degassing, then air bubbles are removed, but the device complexity increases
Solution Approach 1:
The vacuum pump positioned inside the vacuum tank performs self-service degassing by directly drawing air bubbles from the seal oil within the same chamber. This eliminates the need for separate spray systems, external vacuum lines, and complex control mechanisms, simplifying the overall device while maintaining effective seal oil purification
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 enhances degassing efficiency, reduces the machine's size, and minimizes oil consumption, maintaining the hydrogen gas concentration within the machine while eliminating the need for vacuum equipment, thus lowering costs and installation space requirements.
Implementation Method 1
a differential pressure control valve which is disposed between the outlet portion of the degassing pump and the inlet portion of the shaft seal device
Implementation Method 2
a pressure regulating valve which is disposed between the outlet portion of the seal oil cleanup tank and an outlet portion of the degassing pump
Implementation Method 3
an oil film which covers the shaft becomes thinner
Data Source
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AI summary
[Technical Problem] In a shaft seal device mounted rotating electrical machine, the object aims at reducing the overall size of the machine, by promoting the efficiency in a treating part for degassing. [Solution to Problem] The shaft seal device mounted rotating electrical machine includes: a rotating electrical machine which includes a rotating shaft equipped with a shaft seal device having an inlet portion and an outlet portion of seal oil, a main oil tank in which the seal oil supplied to the shaft seal device of the rotating electrical machine is stored, a seal oil cleanup tank which includes an inlet portion connected to an outlet portion of the main oil tank, and has an oil level regulating valve, a degassing pump which includes an inlet portion connected to an outlet portion of the seal oil cleanup tank, a pressure regulating valve which is disposed between the outlet portion of the seal oil cleanup tank and an outlet portion of the degassing pump, a differential pressure control valve which is disposed between the outlet portion of the degassing pump and the inlet portion of the shaft seal device.