Laser Interferometer Nested in Static-Pressure Drive Rod
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing precision transfer equipment faces challenges in achieving highly precise positioning due to offset issues between the laser interferometer's optical path and the driving axis, which impairs the accuracy of movement and positioning, especially when using static-pressure air bearings.
Innovation Solution
The integration of a supplying-discharging static-pressure joint with a laser interferometer, where the laser path aligns with the moving direction, and a transparent plate that reduces pressure within the laser path, preventing fluid from the static-pressure clearance from entering and minimizing reflection errors, allows for precise movement and positioning detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a laser interferometer is positioned to detect displacement of the movable body, then positioning detection capability is achieved, but offset between the laser optical path and driving axis causes measurement errors
Solution Approach 1:
The laser beam path is nested within the driving rod's internal passage, allowing the optical measurement system to be contained within the mechanical drive structure. This eliminates offset errors by ensuring the laser path and driving axis are coaxial, while the driving rod protects the optical path from external interference.
Solution Approach 2:
A transparent plate is introduced as an intermediary component that hermetically seals the laser path while allowing laser light to pass through. This plate prevents fluid from the static-pressure clearance from entering the laser path and minimizes reflection errors, maintaining measurement accuracy.
2Measurement precision
If a static-pressure air bearing is used to eliminate vibration transmission, then motion accuracy is improved, but fluid from the static-pressure clearance may enter the laser path causing measurement errors
Solution Approach 1:
The laser path is nested within the driving rod's internal passage, creating a protected environment that is isolated from the external static-pressure clearance. This spatial nesting prevents fluid contamination while maintaining the benefits of the air bearing system.
Solution Approach 2:
A transparent plate serves as a hermetic barrier between the static-pressure clearance and the laser path. This intermediary component allows laser light transmission while preventing fluid contamination, solving the conflict between vibration isolation and optical path protection.
3Device complexity
If the laser path is exposed to the static-pressure clearance environment, then alignment with the driving axis is simplified, but air turbulence in the laser path degrades measurement precision
Solution Approach 1:
The laser path is nested within the driving rod's internal passage, creating a protected environment that isolates the optical beam from air turbulence in the static-pressure clearance. This nesting maintains measurement precision while the rod's structure guides the laser path along the driving axis.
Solution Approach 2:
The driving rod's internal passage provides a stable, controlled environment for the laser path, protecting it from the turbulent air conditions in the external static-pressure clearance. This creates an inert optical environment that maintains measurement accuracy.
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 enables high-precision movement and positioning by eliminating vibration influences and offset errors, ensuring accurate alignment of the moving and positioning axes, thereby enhancing the overall precision of the transfer equipment.
Implementation Method 1
a static-pressure joint that supplies fluid between a pair of highly precise planes to form a static-pressure clearance
Implementation Method 2
a displacement detector that detects a displacement of the movable body relative to the base, in which the joint is provided by a supplying-discharging static-pressure joint... and the displacement detector is provided by a laser interferometer
Data Source
AI summary
A precision equipment having: a base; a table supported by the base; a tubular rod connected to a side of the table via a joint; a drive mechanism that moves the rod forward and backward; and a laser interferometer that detects displacement of the table relative to the base. The joint is provided by a supplying-discharging static-pressure joint and includes: a movement surface that is connected to the table and is orthogonal to a moving direction of the table; a drive surface that is connected to the rod and faces the movement surface; and a fluid supply channel supplying fluid to a static-pressure clearance between the movement surface and the drive surface. The laser interferometer includes a laser path having an optical axis along the moving direction passing through the inside of the rod of which a pressure is reduced and the drive surface and reflect on the movement surface.