Turbomolecular Pump Lubricant Deflection for Bearing Oil Recirculation
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Solution Overview
Problem
The existing lubricant supply systems for turbomolecular pumps, particularly those using oil-lubricated bearings, face challenges in consistent oil feed rates due to factors like taper angle, oil transfer rate, surface finish, temperature, and rotation speed, which can affect the reliability and efficiency of the bearing operation.
Innovation Solution
A turbomolecular pump design incorporating a deflector and collection channel system that deflects lubricant droplets away from the rotor shaft into a collection channel, allowing for efficient lubricant recirculation and preventing lubricant migration into the pumping mechanism, even when the pump is in an inverted or inclined position, utilizing a lubricant supply system with a conical sleeve and annular channels for effective lubricant distribution and return.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional wicking system with a conical nut is used to supply oil to the rolling bearing, then the lubricant can be delivered to the bearing, but the feed rate is inconsistent and affected by multiple factors including taper angle, transfer rate, surface finish, temperature and rotation speed
Solution Approach 1:
The patent extracts the problematic conical nut and wicking system from the lubricant supply path and replaces it with a direct pump-driven injection system. The pump delivers oil directly to the bearing through controlled injection, eliminating the intermediate wicking and conical surface components that caused inconsistent feed rates.
Solution Approach 2:
The patent incorporates sensors to monitor lubricant flow, bearing temperature, and pump operation status. This feedback enables real-time adjustment of pump parameters to maintain consistent oil feed rate, compensating for variations in temperature, speed, and other operating conditions.
2Reliability
If lubricant is supplied to the rolling bearing during pump operation, then the bearing components are lubricated and cooled, but lubricant can migrate into the pumping mechanism causing contamination and performance degradation
Solution Approach 1:
The patent introduces a deflector component as an intermediary between the bearing and the pumping mechanism. This deflector intercepts lubricant that exits the bearing and redirects it into a collection channel, preventing it from migrating into the pumping mechanism while maintaining the lubrication function.
Solution Approach 2:
The patent segments the pump housing into distinct zones: a bearing support zone with the rolling bearing, and a pumping mechanism zone separated by a partition. The deflector and collection channel create a controlled interface between these zones, allowing lubricant to be contained and managed in the bearing zone without contaminating the pumping mechanism zone.
3Adaptability or versatility
If the pump operates in inverted or inclined positions, then the pump can be installed in various orientations, but lubricant migration into the pumping mechanism becomes more likely
Solution Approach 1:
The deflector acts as a gravity-independent intermediary that actively redirects lubricant flow regardless of pump orientation. Whether the pump is vertical, horizontal, inverted, or inclined, the deflector intercepts lubricant exiting the bearing and channels it into the collection channel, preventing migration into the pumping mechanism in any orientation.
Solution Approach 2:
The partition wall with its integrated deflector and collection channel creates a universal barrier system that functions effectively in all pump installation orientations. This multi-functional design simultaneously provides bearing support, lubricant management, and contamination prevention regardless of gravity direction.
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 ensures consistent lubrication and prevents lubricant migration into the pumping mechanism, enhancing the reliability and operational efficiency of turbomolecular pumps across various orientations, while allowing for effective recirculation of lubricant for continuous operation.
Implementation Method 1
A turbomolecular pump design incorporating a deflector and collection channel system that deflects lubricant droplets away from the rotor shaft into a collection channel
Implementation Method 2
a lubricant transfer device provided on said rotor shaft to transfer lubricant from said lubricant supply system to said rolling bearing
Implementation Method 3
The main purpose of the lubricant is to establish a load-carrying film to separate the bearing components in rolling and sliding contact in order to minimise friction and wear
Implementation Method 4
Other purposes include the prevention of oxidation or corrosion of the bearing components, the formation of a barrier to contaminants and the transfer of heat away from the bearing components
Data Source
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AI summary
A turbomolecular pump has a housing (120), a rotor shaft (24) supported by a plurality of bearings (32, 34) for rotation relative to the housing about an axis of rotation (26), a deflector (40), a lubricant supply system (36) and a lubricant transfer device (38) provided on the rotor shaft. The bearings include a rolling bearing (32) that receives lubricant from the lubricant supply system to via the lubricant transfer device. The rolling bearing is disposed intermediate the lubricant transfer device and the deflector and the deflector is configured to deflect lubricant that passes through the rolling bearing outwardly with respect to the rotor shaft.