Integrated Crane Roller Head Force Sensor Design
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Solution Overview
Problem
Conventional force transducers are prone to failure due to parasitic forces and material deformation, making them difficult to install and maintain, especially when measuring shear forces on machine frames like crane roller heads, where accurate positioning is challenging and parasitic forces can deflect the measurement signal.
Innovation Solution
A force transducer system with a measuring body that has an insertion section with a first axial section for form-fitting support on the machine frame, a second axial section with a circumferential groove for accommodating measuring cells, and a third axial section that maintains an axial distance from the shaft, ensuring the system's stability and preventing parasitic forces from causing misalignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional sleeve-shaped force transducer is positioned between a hollow shaft and a bolt head, then force measurement is enabled, but the system becomes difficult to install and position accurately due to limited accessibility
Solution Approach 1:
The patent combines the force transducer with the shaft into a single integrated assembly. The transducer is positioned within the hollow shaft structure, merging two previously separate components (shaft and transducer) into one unit that is installed as a whole, eliminating the difficulty of positioning the transducer between the shaft and bolt head after assembly.
Solution Approach 2:
The force transducer is pre-positioned and secured within the hollow shaft before the final assembly is completed. This preliminary positioning ensures correct alignment and spacing from the bolt head without requiring difficult post-assembly adjustments, making the overall installation process easier.
2Measurement precision
If the force measuring sleeve is positioned at a sufficient axial distance from the hollow shaft and bolt head, then parasitic forces are avoided, but the system complexity increases due to additional spacing requirements
Solution Approach 1:
The force transducer and hollow shaft are merged into an integrated assembly where the transducer is positioned within the shaft structure. This integration naturally provides the required spacing from the bolt head without requiring separate spacing components, thus maintaining measurement precision while reducing system complexity.
Solution Approach 2:
The hollow shaft itself acts as an intermediary structure that houses the force transducer and provides the necessary spacing from the bolt head. This eliminates the need for additional spacing components or complex positioning mechanisms, simplifying the overall system while maintaining accurate force measurement.
3Measurement precision
If parasitic forces are absorbed using rigid axially aligned spacers, then measurement accuracy is maintained, but the installation difficulty increases due to precise positioning requirements
Solution Approach 1:
The force transducer is integrated within the hollow shaft assembly, and the spacing from the bolt head is built into this integrated structure. This eliminates the need for separate rigid spacers that would require precise positioning, as the spacing is inherently provided by the integrated design, reducing manufacturing precision requirements while maintaining 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
The system allows for easier installation and maintenance by ensuring the axial distance between the shaft and machine frame is maintained, preventing parasitic forces from affecting the measurement, thus providing accurate and reliable force measurements.
Implementation Method 1
deformations caused by shear forces are measured using strain gauges, with the force to be measured acting on the system from the outside at an angle to the machine frame axis
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A force transducer system (10) for measuring a force (F) on a machine frame (16) provided by a user, in particular a crane roller head, is disclosed, the shaft (18) being coaxially connected to a machine frame axis (14), preferably provided by the user, on which at least one rope pulley can be placed and which has at least one axial end section (28) which preferably has an axially outwardly oriented receiving opening (32), wherein the force (F, F') acts substantially radially outside, transversely to the machine frame axis (14), wherein the force transducer system (10) has at least one measuring body (12;12-1, 12-2) which, in an assembled state in which the machine frame (16), the shaft (18) and the force transducer system (10) are permanently coupled to one another, is arranged coaxially to the machine frame axis (14), wherein each of the measuring bodies (12) has an insertion section (40) which: has a first axial section (52) which is configured to be positively engaged in the machine frame (16) in the assembled state in order to support the measuring body (12) on the machine frame (16); has a second axial section (54) which is configured to receive at least one measuring cell (46) which converts a mechanical deformation of the measuring body (12) caused by the force (F, F') into a corresponding signal; and has a third axial section (56) which is configured to be positively engaged in or on the shaft (18) in the assembled state;wherein the second section (54) is formed by a circumferential groove (58) between the first and third sections (52, 56), and wherein the insertion section (40) has an overall axial length that is so short that, in the assembled state, only the second and/or third section (56) projects axially into the end section, or that at most only the end section (28) projects axially into the third section (56).