Rotary Machine Rotor Coolant Path Sealing
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Solution Overview
Problem
The sealing ability between the rotor and stator in rotary machines using a coolant affects the efficiency of converting electric power into torque, as existing technologies struggle to effectively seal the coolant, leading to reduced performance and increased motor losses.
Innovation Solution
A rotary machine design featuring a rotor shaft coolant path and a rotor coolant path that guides coolant through the rotor shaft and rotor, respectively, with inlet and discharge ports, ensuring the coolant is sealed outside the housing, preventing it from entering the air gap between the rotor and stator, and utilizing existing components without additional parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a coolant path is introduced to cool the rotor and stator, then cooling efficiency is improved, but sealing ability deteriorates as coolant may leak into the air gap
Solution Approach 1:
The coolant path is segmented into separate channels: a stator coolant path for cooling the stator and a rotor coolant path for cooling the rotor. This segmentation allows independent cooling of each component while maintaining proper sealing, as each path has its own inlet and outlet positioned to prevent coolant leakage into the air gap between rotor and stator.
Solution Approach 2:
The patent uses the housing and outer housing as intermediary structures to contain and direct the coolant flow. The housing receives coolant at its inlet and directs it to the stator coolant path, while the outer housing receives coolant for the rotor coolant path. These intermediary structures ensure proper sealing and prevent coolant from entering the air gap while still achieving effective cooling.
2Reliability
If sealing structures are added to prevent coolant leakage, then sealing ability is improved, but device complexity increases
Solution Approach 1:
The housing and outer housing serve multiple functions: they provide structural support, contain the coolant paths, direct coolant flow, and provide sealing against coolant leakage. By making these existing components multi-functional, the patent achieves reliable sealing without adding separate complex sealing structures such as seals, gaskets, or sealing rings.
Solution Approach 2:
The coolant path design itself provides the sealing function. The inlet and outlet positions, combined with the natural flow direction of the coolant through the stator and rotor coolant paths, create a self-sealing effect where the coolant flow pattern and path configuration prevent leakage into the air gap without requiring additional active sealing mechanisms.
3Temperature
If coolant discharge is positioned inside the housing, then cooling effectiveness is improved, but coolant may enter the air gap causing motor losses
Solution Approach 1:
Instead of discharging coolant inside the housing near the air gap (which would improve cooling but risk leakage), the patent inverts the approach by positioning the outlet outside the housing. The coolant is discharged to the exterior environment through the outer housing, which eliminates the risk of coolant entering the air gap and causing motor losses while still achieving effective cooling of the rotor and stator components.
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 design enhances cooling efficiency, reduces motor losses, and maintains the air gap between the rotor and stator, improving the conversion of electric power into torque without the need for complex sealing structures, thereby optimizing the rotary machine's performance.
Implementation Method 1
a rotor shaft coolant path that is formed inside the rotor shaft and includes an inlet exposed to the outside of the outer housing to take in a coolant from the outside of the rotor shaft and an exit communicating with an annular clearance between the rotor shaft and the rotor to pass the coolant taken in from the inlet to the annular clearance
Implementation Method 2
a rotor coolant path that is formed inside the rotor and includes an intake communicating with the annular clearance and a discharge port arranged outside the housing to discharge the coolant taken through the intake to a space between the housing and the outer housing
Data Source
AI summary
On an inner circumference side of a stator fixed in an inner housing, a rotor is arranged. The rotor rotates through a bearing with respect to a center shaft that is a stationary shaft fixed to outer housings. Oil introduced into a rotor oil inlet path in the center shaft flows through a communication path and a clearance on an outer circumference of the center shaft into an oil path in the rotor. The oil flowing through the oil path cools a permanent magnet, lubricates the bearing, and is discharged from a rotor oil discharge port to the outside of the inner housing. The oil in the clearance is sealed with a thread seal, i.e., an inner thread formed in an inner face of an end ring and is prevented from flowing toward the bearing.