X-Y Constraining Unit with Bearing Balls for Stage Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional X-Y stage apparatuses with H-shaped air slides suffer from deteriorated yawing attitude precision due to direct displacement propagation and rigidity issues, leading to scoring and oscillations during acceleration and deceleration.
Innovation Solution
The X-Y constraining unit incorporates a Y-axis base with a through hole connected to a Y-axis slider, an X-axis base connected to an X-axis guide rail, and a shaft fixed between them, with bearing balls surrounding the shaft to enhance rotational stability and reduce stress on the sliders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If two Y-axis sliders are separately driven with direct connection to X-axis shaft, then individual Y-axis movement is achieved, but displacement propagation causes deteriorated yawing attitude precision
Solution Approach 1:
The patent introduces a constraint mechanism with bearing balls as an intermediary between the Y-axis sliders and the X-axis shaft. This mediator absorbs displacement variations and prevents direct transmission of movement errors to the shaft, thereby maintaining yawing attitude precision while allowing independent Y-axis slider operation.
Solution Approach 2:
The constraint mechanism is divided into separate constraint units, each independently constraining one Y-axis slider to the X-axis shaft. This segmentation allows each slider to be controlled independently while maintaining overall system precision through individual constraint enforcement.
2Strength
If Y-axis sliders are directly connected to X-axis shaft with bolts, then structural connection is achieved, but contact between sliders and shaft causes scoring
Solution Approach 1:
The patent replaces the direct mechanical bolt connection system with a bearing ball-based constraint system. This substitution eliminates direct contact and friction between the Y-axis sliders and the X-axis shaft, preventing scoring while maintaining structural integrity through the bearing-mediated constraint.
Solution Approach 2:
Bearing balls are introduced as intermediary elements between the Y-axis sliders and the X-axis shaft. These bearing balls prevent direct contact between the slider surfaces and the shaft, eliminating the scoring mechanism while still providing the necessary structural connection and constraint.
3Ease of manufacture
If free end configuration is used for Y slider, then ease of assembly is improved, but rigidity at free end decreases causing deteriorated yawing precision during acceleration
Solution Approach 1:
The constraint mechanism is pre-installed on the X-axis shaft before assembling the Y-axis sliders. This preliminary action ensures that the constraint structure is already in place to provide rigidity and precision during acceleration, while still allowing for easy assembly of the slider components themselves.
Solution Approach 2:
The bearing ball constraint acts as a preliminary structural intermediary that provides rigidity to the Y-axis slider assembly during acceleration and deceleration phases, preventing the rigidity problems associated with free-end configurations while maintaining assembly ease.
4Shape
If conventional H-shaped air slide is used, then low profile structure is achieved, but displacement propagation causes oscillations during acceleration and deceleration
Solution Approach 1:
The constraint mechanism with bearing balls serves as a cushioning element that absorbs and dampens displacement propagation and oscillations before they can affect the overall system stability during acceleration and deceleration, while maintaining the low-profile H-shaped structure.
Solution Approach 2:
The bearing ball constraint mechanism acts as a stabilizing intermediary that prevents displacement propagation through the H-shaped structure during dynamic operation, eliminating oscillations while preserving the compact low-profile design.
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 configuration improves yawing attitude precision by absorbing displacement and reducing stress, preventing scoring and oscillations, while allowing for stable control and easy maintenance by isolating potential breakages to the constraining units.
Implementation Method 1
a plurality of bearing balls (84) located between an inner peripheral surface of the through hole (811) and an outer peripheral surface of the shaft (83) and arranged so as to circumferentially surround the shaft (83)
Data Source
AI summary
Provided are X-Y constraining units having excellent yawing attitude precision as well as a stage apparatus and a vacuum stage apparatus, each including the X-Y constraining units. The X-Y constraining units 8 and 9 includes: Y-axis bases 81 and 91 respectively connected to Y-axis sliders 4 and 5 and having a through hole extending along Z direction; X-axis bases 82 and 92 respectively connected to an X-axis guide rail 6; shafts 83 and 93 respectively inserted into the through hole and fixed to the X-axis bases 82 and 92; and a plurality of bearing balls which are located between an inner peripheral surface of each of the through hole and an outer peripheral surface of the shafts 83 and 93, and are arranged so as to circumferentially surround the shafts 83 and 93. Each of the stage apparatus 1 and the vacuum stage apparatus includes the X-Y constraining units.