Power Chuck Centering Device for Heavy Workpiece Alignment
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Solution Overview
Problem
Existing power-operated chucks fail to precisely center and sustainably support workpieces with large diameters and weights, leading to machining inaccuracies due to bearing play and weight distribution issues, which are critical for high-precision components like rotors in electric motors.
Innovation Solution
Incorporating a centering device that applies a radially acting force to compensate for manufacturing errors and weight changes during machining, allowing precise central alignment and continuous support of workpieces, even with diameters over 0.5 meters, using a force-locking arrangement with a piston and wedge rod, and optionally hydraulically or threaded spindles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the chuck uses a piston mounted in an axially movable arrangement in the base body to actuate clamping jaws, then the clamping function is achieved, but bearing play between the piston and base body causes manufacturing inaccuracies that cannot be compensated
Solution Approach 1:
The chuck is divided into two independent functional systems: a clamping system (piston, clamping jaws, wedge rods) and a centering system (centering device with independent actuation). This segmentation allows the centering function to operate independently of the clamping function, eliminating the transmission of bearing play errors from the clamping mechanism to the workpiece centering.
Solution Approach 2:
The centering device acts as an intermediary mechanism that directly centers the workpiece on the chuck axis without being influenced by the bearing play in the piston-base body arrangement. It mediates between the imperfect clamping mechanism and the requirement for precise workpiece centering.
2Ease of manufacture
If material is removed from the workpiece during machining, then the workpiece becomes lighter, but the position of the workpiece changes in relation to the chuck
Solution Approach 1:
The centering device is designed to be dynamically adjustable during the machining process. As material is removed and the workpiece weight changes, the centering device can be repositioned to maintain optimal centering, adapting to the changing clamping conditions throughout the machining operation.
Solution Approach 2:
The system incorporates the ability to monitor and adjust the centering position in response to changes in workpiece weight during machining. The centering device can be adjusted based on the changing gravitational effects on the clamping jaws, maintaining precision throughout the machining process.
3Force
If the chuck is designed to support extremely heavy workpieces (20 tons), then the clamping force is sufficient, but the individual clamping jaw has to absorb all clamping forces at certain angular positions requiring extremely sturdy construction
Solution Approach 1:
The support function is segmented between the clamping jaws and the centering device. The centering device shares the load by providing radial support forces, reducing the burden on individual clamping jaws and allowing a more balanced, less overly-sturdy overall structure while maintaining the ability to handle 20-ton workpieces.
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
Ensures precise central positioning and sustained support of heavy workpieces throughout machining, reducing machining errors and the need for re-clamping by independently adjusting centering devices to maintain alignment despite material removal and weight changes.
Implementation Method 1
at least one centering device (11) is provided which acts on a side on the workpiece (2) with a radially acting centering force (Fz)
Implementation Method 2
Both the clamping jaw set and the centering clamping jaws are adapted to be actuated by wedge rods
Implementation Method 3
the actuating element configured as a piston which is mounted in an axially movable arrangement in the base body of the chuck
Implementation Method 4
the actuating element configured as a piston which is mounted in an axially movable arrangement in the base body of the chuck
Data Source
AI summary
A power-operated chuck for machine tools, the chuck having a base body attachable to the machine tool, at least two clamping jaws held moveably in the base body are synchronously controlled and moved radially onto a workpiece to be clamped by one wedge rod each, and an actuating element is held in an axially movable arrangement in the base body and is connected in a force-locking arrangement with each of the wedge rods and is held coaxially in the base body in relation to its longitudinal axis, there being play between the actuating element and the base body, the chuck permitting central positioning of the workpiece to be clamped in relation to the longitudinal axis of the chuck and, the chuck permitting the centering adjustment to be undertaken throughout the machining process.