Symmetrical Machine Housing for Optical Lens Processing
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Solution Overview
Problem
Existing spectacle lens processing machines face challenges with high intrinsic weight, structural deformations, and vibrations, leading to inaccuracies and chatter marks due to their large and heavy construction, which affects the precision and quality of processed lenses.
Innovation Solution
A compact machine design with a symmetrical machine housing that encloses the working space, featuring a workpiece spindle and fast-tool servo arranged on either side, and a carriage guided by symmetrical guide surfaces, ensuring high structural and thermal stiffness, reduced weight, and equal force and thermal paths to prevent axial displacements and vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a heavy concrete polymer machine stand with large wall thicknesses is used, then good damping characteristics and structural stability are achieved, but the machine becomes excessively heavy (estimated at 1200 kilograms)
Solution Approach 1:
The patent employs a composite structure combining a lightweight aluminum alloy base frame with strategically placed stiffening ribs and reinforcement elements. This composite approach achieves the required structural stability and damping characteristics without relying on heavy concrete polymer construction, reducing the machine stand weight from an estimated 1200 kg to a much lighter configuration while maintaining performance.
Solution Approach 2:
The machine stand is segmented into functional zones with localized reinforcement. Instead of uniformly thick walls throughout, stiffening ribs and reinforcement are concentrated in areas experiencing highest dynamic loads and vibrations. This segmentation allows weight reduction in non-critical areas while maintaining structural integrity where needed.
2Weight of stationary object
If a lightweight cubic machine bed construction is used, then reduced weight and compact size are achieved, but structural deformations occur under highly dynamic loads due to bending and torsion
Solution Approach 1:
The aluminum alloy machine bed incorporates integrated stiffening ribs and reinforcement structures that create a composite-like behavior within the single material. These structural features increase the moment of inertia and resistance to bending and torsion under dynamic loads, preventing the structural deformations that would otherwise occur in simple cubic constructions while maintaining the lightweight advantage.
Solution Approach 2:
The patent incorporates curved and contoured reinforcement ribs rather than simple flat bracing. These curved structural elements provide more efficient load distribution and higher resistance to bending moments compared to straight rib configurations, enhancing the machine bed's stiffness-to-weight ratio and preventing deformations during high-speed tool oscillation and workpiece rotation.
3Weight of stationary object
If structural deformations are allowed in the machine bed, then lighter construction is possible, but axial displacements and vibrations are transmitted to the tool and workpiece drives causing chatter marks and inaccuracies
Solution Approach 1:
The reinforced aluminum alloy construction acts as a vibration-damping composite structure. The stiffening ribs and reinforcement elements create a complex structural geometry that dissipates vibrational energy and prevents the transmission of axial displacements to the precision drives. This eliminates chatter marks while maintaining the lightweight design, avoiding the need for heavy concrete polymer construction.
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 design achieves high structural stiffness, reduces weight, and maintains precise calibration, minimizing thermal and dynamic deformations, resulting in improved processing accuracy and reduced risk of errors, while allowing the use of lighter materials and efficient heat dissipation.
Implementation Method 1
the guide arrangement is so mounted on the machine housing that the processing plane (F-X plane) extends between the two guide surfaces... symmetrical machine housing... equal force and thermal paths to prevent axial displacements and vibrations
Data Source
AI summary
The invention relates to a machine for processing plastic workpieces. A machine housing surrounds a working chamber located between a workpiece spindle for rotationally driving the workpieces about a workpiece axis of rotation and a fast tool servo for producing an oscillating feeding movement of a rotary tool in the direction of the workpieces. The workpiece spindle is provided with a carriage which can be driven and is guided on at least two guide surfaces of a guiding arrangement in order to produce a relative advancing movement between the workpiece and the rotary tool. The advancing movement runs transversely with respect to the feeding movement and defining therewith a processing plane in which during processing the rotary tool engages with the workpiece. The guiding arrangement is mounted on the machine housing such that the processing plane extends between the two guide surfaces.