Vacuum Pump Bearing Layout for Oil Retention in Vertical Mounting
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Solution Overview
Problem
The challenge is to reduce the installation space of vacuum pumps in semiconductor and flat panel manufacturing while ensuring reliable operation and preventing lubricating oil leakage, especially when the pumps are arranged vertically and operate at high speeds.
Innovation Solution
A bearing apparatus with a rotating cylinder and bearing casing that forms a circulating flow of lubricating oil, using downward and upward ribs to prevent leakage, and contact seals to ensure reliable lubrication and cooling of the bearings, thereby reducing installation space and preventing oil leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the vacuum pump is arranged vertically and operated at higher speed, then the installation space is reduced, but lubricating oil may leak below the bearing apparatus due to gravity and pressure difference
Solution Approach 1:
The bearing casing is divided into multiple chambers by partition walls, with each chamber containing a bearing. The rotating cylinder is segmented with multiple oil retention ribs that create separate oil retention regions. This segmentation allows independent oil retention in each region, preventing leakage even when the pump is vertically arranged.
Solution Approach 2:
Oil retention ribs are introduced as intermediary structures between the rotating cylinder and the bearing casing. These ribs create oil retention regions that act as barriers, preventing lubricating oil from leaking below the bearing apparatus under the influence of gravity and pressure difference in vertical arrangements.
2Productivity
If the vacuum pump size is increased to achieve high pumping speed, then the pumping performance is improved, but the installation space in the manufacturing plant increases
Solution Approach 1:
The patent transitions from a horizontal arrangement to a vertical arrangement of the vacuum pump. By changing the spatial dimension from horizontal to vertical, the pump achieves high pumping speed while reducing the footprint area required for installation in the manufacturing plant.
Solution Approach 2:
The bearing housing and bearing casing are merged into an integrated structure where the bearing casing houses both the bearing housing and the rotating cylinder. This merging reduces the overall number of separate components and compactly arranges the internal structure, contributing to reduced installation space.
3Reliability
If downward ribs and upward ribs are added to prevent oil leakage, then the oil retention capability is improved, but the device complexity increases
Solution Approach 1:
The rotating cylinder serves multiple functions: it rotates with the shaft to drive the pump mechanism, and simultaneously functions as an oil retention structure through its integrated oil retention ribs. The bearing casing also serves dual purposes by housing both the bearing housing and the rotating cylinder, while the partition walls create multiple oil retention regions within a single structure. This multi-functionality reduces the need for separate dedicated oil retention 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
The solution effectively reduces the installation space of vacuum pumps, ensures reliable operation at high speeds, and prevents lubricating oil leakage, maintaining the functionality of the bearings and preventing contamination in the process chamber.
Implementation Method 1
an effect of a pressure difference between a bearing chamber and a pump chamber
Implementation Method 2
lubricating oil in the bearing apparatus may leak below the bearing apparatus due to gravity
Data Source
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AI summary
A bearing apparatus capable of reducing an installation space of a vacuum pump and sufficiently exhibiting a function of a bearing is disclosed. The bearing apparatus comprises: a bearing configured to support a shaft extending in a vertical direction; a bearing housing configured to house the bearing; a rotating cylinder disposed below the bearing housing and capable of fixing to the shaft, and a bearing casing configured to house the bearing, the bearing housing, and the rotating cylinder. The bearing casing comprises a plurality of cylindrical upward ribs extending upward from a bottom wall of the bearing casing and the downward ribs and the upward ribs are alternately arranged.