Sealed Robot Drive With External Stator for Vacuum Efficiency
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Solution Overview
Problem
Existing robotic drive technologies face limitations in ultra-high vacuum and corrosive environments due to constraints on air gap size caused by isolation walls, leading to reduced motor efficiency and potential contamination or overheating issues with stator coils.
Innovation Solution
A sealed robotic drive system with a non-magnetic isolation wall that minimizes the air gap between the stator and rotor, using a laminated rotor and stator configuration with ferromagnetic materials and non-conductive layers to reduce Eddy current losses, and positioning sensors outside the isolated environment to prevent exposure to harsh conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a non-magnetic isolation wall is used to seal the motor rotor from the stator, then the motor can operate in ultra-high vacuum and corrosive environments, but the air gap between rotor and stator increases due to isolation wall thickness and runout tolerances, reducing motor efficiency
Solution Approach 1:
A non-magnetic isolation wall acts as an intermediary barrier between the rotor and stator, allowing the motor to operate in ultra-high vacuum and corrosive environments while maintaining magnetic flux flow across the wall. The isolation wall mediates the conflict between environmental sealing and magnetic coupling, enabling both functions to coexist despite the increased air gap.
2Strength
If the isolation wall thickness is increased to provide structural integrity in high vacuum, then the sealed environment can maintain vacuum integrity, but the air gap between rotor and stator becomes larger, severely decreasing motor efficiency
Solution Approach 1:
The patent optimizes the isolation wall thickness parameter to achieve the minimum required structural integrity for vacuum sealing while minimizing the air gap increase. By carefully controlling the thickness parameter and runout tolerances, the design balances structural strength requirements with motor efficiency preservation.
3Volume of moving object
If stator coils are located within the sealed vacuum environment, then the motor can be compact, but the coils outgas undesirable compounds and overheat, making the solution expensive and impractical
Solution Approach 1:
The stator coils are extracted from the vacuum environment and placed in the atmospheric environment outside the sealed chamber. The rotor remains in the vacuum environment while the stator is isolated, allowing the motor to maintain compact size without subjecting the stator coils to vacuum conditions that cause outgassing and overheating.
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
The solution enhances magnetic efficiency and precision position control while maintaining structural integrity and preventing contamination, thereby improving the reliability and performance of robotic drives in challenging environments.
Implementation Method 1
utilizing a laminated rotor and stator configuration with ferromagnetic materials and non-conductive layers to reduce Eddy current losses
Implementation Method 2
This allows for the magnetic flux to flow between the rotor and stator across the isolation wall
Data Source
AI summary
A transport apparatus including a housing, a drive mounted to the housing, and at least one transport arm connected to the drive where the drive includes at least one rotor having at least one salient pole of magnetic permeable material and disposed in an isolated environment, at least one stator having at least one salient pole with corresponding coil units and disposed outside the isolated environment, where the at least one salient pole of the at least one stator and the at least one salient pole of the rotor form a closed magnetic flux circuit between the at least one rotor and the at least one stator, and at least one seal configured to isolate the isolated environment where the at least one seal is integral to the at least one stator.