Screw Rotor Helical Groove Cutting With Reattachment and Error Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing screw rotors require specialized 5-axis machining centers to avoid interference between the rotary spindle and holder, limiting the use of general machine tools.
Innovation Solution
A method involving multiple attachment and detachment steps of the workpiece to a machine tool holder, allowing for the formation of helical grooves using a standard machine tool by separating the holder from the rotary spindle during machining, and incorporating measurement and correction steps to minimize positional errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a 5-axis machining center is used to machine helical grooves, then machining precision can be maintained, but the holder and rotary spindle come into contact causing interference
Solution Approach 1:
The machining process is segmented into multiple steps with different attachment configurations. The workpiece is attached to the holder in different orientations for different portions of the helical groove machining, allowing the cutter to reach all areas without holder-spindle interference
Solution Approach 2:
The problem is solved by changing the dimensional approach - instead of trying to machine all portions in a single attachment configuration, the workpiece is reattached in different orientations (different dimensional perspectives) to allow the cutter to access different portions of the helical groove without interference
2Object-affected harmful factors
If a special 5-axis machining center structure is used to avoid interference, then holder and rotary spindle do not contact, but device complexity increases
Solution Approach 1:
Instead of using a statically complex machine tool structure, the solution employs dynamic reconfiguration - the workpiece attachment is changed between machining steps. This dynamic approach to process organization avoids the need for complex machine tool hardware modifications
Solution Approach 2:
The machining process is divided into multiple steps with different attachment configurations, allowing standard machine tools to be used without modification. This segmentation of the manufacturing process eliminates the need for complex specialized equipment
3Productivity
If the workpiece is attached once to machine all helical grooves, then productivity is high, but positional errors increase due to angle changes during machining
Solution Approach 1:
The workpiece is pre-attached in optimal orientations for specific portions before machining begins. By preparing the correct attachment configuration in advance for each portion, the cutter maintains the correct angle throughout machining of that portion, eliminating positional errors while maintaining efficient continuous machining
Data Source
AI summary
A plurality of helical grooves are formed in a workpiece having a cylindrical shape. Each of grooves is divided into a first portion including an end portion on a first end side of the workpiece and a second portion including an end portion on a second end side of the workpiece. A method of manufacturing a screw rotor of a screw compressor includes attaching a first end of the workpiece to a holder of a machine tool, finishing the first portion of each of the plurality of helical grooves by cutting, detaching the workpiece from the holder, attaching a second end of the workpiece detached from the holder to the holder, and finishing the second portion of each of the plurality of helical grooves by cutting.