Grinding Support Device for Shaft Parts
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Solution Overview
Problem
Existing grinding technologies face challenges in maintaining accuracy and stability during the external grinding of long, thin, rotationally symmetrical shafts, particularly due to the loss of reference axis and thermal inaccuracies when transitioning from center-based grinding to centerless grinding, which results in reduced precision and increased processing time.
Innovation Solution
A method and system where the shaft part with centering bores is continuously supported between centers using a support device that tracks the actual diameter of the shaft part during grinding, ensuring the reference axis is maintained, and utilizing a combination of grinding wheel and support wheel for precise control and support, eliminating the need for steady rests.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If centerless grinding is used for external grinding of rotationally symmetrical shafts, then mass production efficiency is improved, but reference axis accuracy deteriorates due to loss of centering reference
Solution Approach 1:
The grinding process is divided into two distinct phases: first centerless grinding for efficient material removal, then center-based finish grinding for precision. This segmentation allows each method to perform its optimal function - centerless grinding for productivity and center-based grinding for accuracy.
Solution Approach 2:
Centerless grinding is performed as a preliminary operation to remove the majority of material quickly, preparing the workpiece for the subsequent precision finish grinding between centers. This preliminary action maximizes efficiency while setting up conditions for high-precision final machining.
2Manufacturing precision
If grinding between centers is used for long flexible shafts, then reference axis accuracy is maintained, but additional support with steady rests is required increasing device complexity
Solution Approach 1:
A support device acts as an intermediary element between the grinding wheel and the workpiece, providing necessary support for long flexible shafts during centerless grinding without requiring complex steady rest arrangements. This mediator enables stable grinding of flexible workpieces while maintaining simplicity.
3Loss of time
If transition from center-based grinding to centerless grinding is made, then processing time is reduced, but thermal inaccuracies and surface markings occur
Solution Approach 1:
The grinding process is segmented into centerless grinding for roughing (fast material removal) and center-based grinding for finishing (high precision). This segmentation prevents thermal inaccuracies and surface markings by using the appropriate method for each stage.
Solution Approach 2:
The process maintains continuous useful action by seamlessly transitioning from centerless to center-based grinding without interrupting the workflow, ensuring both efficiency and quality are maintained throughout the complete machining cycle.
4Stability of the object's composition
If steady rests are used to support flexible workpieces during grinding, then grinding stability is improved, but optical tracks remain on the ground surface
Solution Approach 1:
A specially designed support device serves as an intermediary that provides grinding stability for flexible workpieces without creating optical tracks on the surface. This mediator enables stable machining while preserving surface quality by avoiding direct contact that would cause marking.
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 approach ensures high-quality grinding results with maintained dimensional, shape, and positional tolerances, preventing thermal inaccuracies and surface markings, while maintaining the advantages of both center-based and centerless grinding processes without the need for additional support, thus achieving precise and efficient grinding of flexible workpieces.
Implementation Method 1
external grinding of a shaft part with rotationally symmetrical sections and end faces
Implementation Method 2
the shaft part is supported on the rotationally symmetrical sections by means of a support device
Data Source
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AI summary
The invention relates to a method for grinding the exterior of a shaft part (10) with rotationally symmetrical sections and bases which have centering bores and which define a reference longitudinal axis and rotational axis of the shaft part. In the method according to the invention, the shaft part (10) to be ground is held between tips (11, 14) which engage into the centering bores during the grinding process using a grinding disk (1), and the shaft part is additionally supported on the rotationally symmetrical sections by means of a support device (2, 2', 3, 35). Furthermore, the current diameter values of the rotationally symmetrical sections of the shaft part (10) are measured and transmitted to a controller, by means of which the support device (2, 2', 3, 35) is updated with respect to the measured diameter values while continuously supporting the rotationally symmetrical sections until the target dimensions of the shaft part (10) are achieved. The invention additionally relates to a system for carrying out the method, consisting of a grinding machine and such a shaft part (10). The grinding machine belonging to the system has a support device (2, 2', 3, 35) with a first and a second support unit, which can be moved relative to each other and dependent on each other. The measurement signals of the current diameter of the rotationally symmetrical section of the shaft part (10) are forwarded to a controller by means of the measuring device (21), and the first and the second support unit (2, 2', 3, 35) can be constantly updated with respect to the current diameter of the rotationally symmetrical section on the basis of the measurement signals such that the shaft part (10) is doubly supported by the support units (2, 2', 3, 35) opposite the grinding disk (1) and by tips (11, 14) which are in engagement with the shaft part.