Seal Oil Supply Device for Rotating Electric Machine
Solution Overview
Problem
Conventional seal oil supply devices for rotating electric machines fail to maintain sufficient oil supply pressure at extremely low pressures, leading to increased component sizes and oil amounts due to unnecessary gaps between the rotary shaft and seal ring, especially during test operations.
Innovation Solution
A seal oil supply device with a dual routing system, utilizing both a differential pressure regulation valve and a relief valve to ensure necessary oil supply pressure, with the differential pressure regulation valve used during normal operations and the relief valve activated at low pressures to maintain a minimum oil supply pressure of 0.10 MPa-g.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gap between the rotary shaft and seal ring is designed to be large to ensure sufficient gap at low pressure operation, then the gap is sufficient during test operation, but during normal operation the gap becomes larger than necessary and the oil amount increases
Solution Approach 1:
The patent applies dynamics by making the oil supply pressure adjustable based on operating conditions. The oil supply pressure adjusting means dynamically changes the oil supply pressure to be higher during test operation (low gas pressure) and lower during normal operation (high gas pressure), optimizing the gap between rotary shaft and seal ring for each condition rather than using a fixed large gap design
Solution Approach 2:
The patent changes the parameter of oil supply pressure according to operating conditions. By adjusting the oil supply pressure to be higher at low gas pressure and lower at high gas pressure, the system optimizes the seal ring gap and oil amount for each operational state, resolving the contradiction between ensuring sufficient gap and minimizing oil amount
2Device complexity
If a single routing system is used with differential pressure regulation valve, then the device structure is simple, but the necessary oil supply pressure cannot be ensured at extremely low pressures
Solution Approach 1:
The patent segments the oil supply system into two separate routes: a first route for normal operation conditions and a second route for test operation conditions. The oil supply pressure adjusting means selectively switches between these two routes based on gas pressure levels, ensuring appropriate oil supply pressure for each condition while maintaining relatively simple device structure
Solution Approach 2:
The oil supply pressure adjusting means provides multi-functionality by serving two different operational conditions through a single device. It can maintain differential pressure via the first route during normal operation and provide elevated absolute pressure via the second route during test operation, making the system adaptable to multiple scenarios
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 approach ensures a necessary oil supply pressure even at extremely low pressures, suppressing rotary shaft expansion and reducing the gap between the shaft and seal ring, thereby reducing oil amounts and device sizes.
Implementation Method 1
supplying the seal oil through a second route from the seal oil pump via a relief valve, when the rotating electric machine is operated with a pressure of the hydrogen gas being an extremely low pressure close to 0.00 MPa-g
Implementation Method 2
seal oil is supplied from a seal oil pump to a seal ring of a rotating electric machine in which hydrogen gas is sealed, via a differential pressure regulation valve for regulating a pressure of the seal oil
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3(a)~3(b)
AI summary
The present invention achieves oil amount reduction and size reduction in a seal oil supply device for rotating electric machine by suppressing expansion of a rotary shaft due to its temperature increase and reducing the gap between the rotary shaft and a seal ring in normal operation. In this seal oil supply device for rotating electric machine, seal oil is supplied from a seal oil pump (7) to a seal ring (3) of a rotating electric machine (1) in which hydrogen gas is sealed, via a differential pressure regulation valve (8) for regulating a pressure of the seal oil. A first route is provided for supplying the seal oil from the seal oil pump (7) via the differential pressure regulation valve (8), and in addition, a second route is provided for supplying the seal oil from the seal oil pump (7) via a relief valve (15).