Spindle Air Purging Below the Bearing to Block Chip Penetration
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Solution Overview
Problem
Existing cutting apparatuses face issues with chip adhesion to bearings due to negative pressure created by high-speed rotation, leading to interference with the machining process.
Innovation Solution
A spindle design that maintains a positive pressure below the bearing by controlling air flow through an air passage and outlet, preventing chip penetration and ensuring the bearing remains clean and functional.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-speed rotation of the main shaft is performed, then machining productivity is improved, but negative pressure around the bearing causes chips to penetrate and adhere to the bearing
Solution Approach 1:
The air purger applies air pressure in advance to the bearing region before chips can penetrate due to negative pressure. This preliminary counter-action prevents the harmful effect of chip adhesion while maintaining high-speed rotation for productivity.
Solution Approach 2:
The invention converts the harmful negative pressure effect into a beneficial air flow pattern. By introducing air through the air purger, the negative pressure region is transformed into a controlled positive pressure zone that prevents chip penetration while maintaining the high-speed rotation capability.
2Object-affected harmful factors
If air purging is supplied to create positive pressure around the bearing, then chip penetration is prevented, but insufficient positive pressure still allows chips to penetrate
Solution Approach 1:
The air passage is specifically designed to deliver air pressure locally to the bearing region where it is most needed. This localized air supply ensures sufficient positive pressure is created exactly where chips attempt to penetrate, improving both chip prevention and reliability.
Solution Approach 2:
The air passage acts as an intermediary structure that efficiently transmits air pressure from the air purger to the bearing region. This intermediary mechanism ensures the air pressure reaches the critical area with sufficient force to reliably prevent chip penetration.
3Device complexity
If air outlet is positioned below the bearing, then air flow path is simplified, but chips can penetrate into the air passage through the air outlet
Solution Approach 1:
The air purger creates positive pressure in advance in the region below the bearing, preventing chips from entering the air passage through the air outlet. This preliminary pressure application occurs before chips can exploit the simplified air outlet path.
Solution Approach 2:
The simplified air outlet structure, which initially appears to create a vulnerability for chip entry, is transformed into an effective design by using the air purger to create positive pressure that prevents chip penetration while maintaining the simple structure.
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 prevents chip adhesion to the bearing, ensuring smooth rotation and maintaining the bearing's cleanliness, thus supporting the main shaft effectively during machining.
Implementation Method 1
An inner portion of the housing located below the bearing is thus maintained at a positive pressure
Implementation Method 2
Because air outside the housing is kept from flowing into the air passage through the air outlet, chips produced during machining of the workpiece with the machining tool are prevented from penetrating into the air passage through the air outlet
Data Source
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AI summary
A spindle includes a housing, a bearing housed in the housing, a main shaft rotatably supported by the bearing, a collet chuck extending into a through hole of the main shaft to grip a machining tool and movable in an axial direction of the main shaft, a draw bar connected to the collet chuck, an air inlet above the bearing and through which air is introduced into the housing, an air passage defined in the housing such that the air introduced into the housing through the air inlet flows below the bearing, and an air outlet in the housing and below the bearing and through which the air flowing below the bearing is discharged out of the housing.