Power Tool Attachment Torque Sensing via Intermediate Gear Shaft
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power tool attachment parts, such as crowfoots, struggle with inaccurate torque measurement due to internal measurement systems that do not account for radial forces, particularly when using spur gear wheels with straight teeth, and require complex helical gear designs for accurate torque detection.
Innovation Solution
A power tool attachment part with a torque sensor that detects radial forces on an intermediate gear shaft using piezo-electric elements or strain gauges, allowing accurate torque measurement regardless of gear tooth configuration, including spur gears, and an electronics unit to process and transmit these measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If helical gear wheels with angled teeth are used for torque measurement, then torque measurement accuracy is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent replaces the mechanical torque measurement method (requiring helical gears with angled teeth to convert rotational torque into measurable axial or radial forces) with a direct radial force detection system. The torque sensor directly measures radial forces on the intermediate gear shaft, eliminating the need for complex helical gear geometry to enable measurement.
Solution Approach 2:
The patent introduces a torque sensor as an intermediary measurement device that directly detects radial forces on the intermediate gear shaft. This intermediary sensor system allows torque measurement without requiring the gear wheels themselves to have special helical geometry, thereby simplifying the overall device while maintaining measurement accuracy.
2Measurement precision
If helical gear wheels with angled teeth are used for torque measurement, then torque measurement accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces the complex helical gear design with simple spur gears that have straight teeth. The torque measurement function is achieved not through the gear geometry itself, but through a separate torque sensor that detects radial forces on the shaft, making the gears much easier and cheaper to manufacture.
Solution Approach 2:
The patent uses inexpensive torque sensors (based on piezoelectric elements or strain gauges) to achieve accurate torque measurement. These sensors are relatively simple, inexpensive components compared to the complex helical gears they replace, thereby reducing overall manufacturing cost while maintaining measurement precision.
3Device complexity
If internal torque measurement systems are used in power tools, then device integration is improved, but measurement accuracy deteriorates due to inability to detect radial forces
Solution Approach 1:
The patent introduces a torque sensor as an intermediary measurement device within the attachment part that specifically detects radial forces on the intermediate gear shaft. This intermediary sensor enables accurate torque measurement in the attached tool, overcoming the limitation of standard internal measurement systems that cannot detect radial forces.
Solution Approach 2:
The patent segments the measurement function from the power tool's internal system by placing a dedicated torque sensor in the attachment part itself. This segmentation allows the attachment part to independently perform accurate torque measurement through radial force detection, rather than relying on the power tool's internal measurement system.
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
Enables precise torque measurement by detecting radial deformations, facilitating the use of simpler and cheaper spur gears while maintaining accuracy, and providing adaptable length for various applications.
Implementation Method 1
The torque sensor may comprise a piezo electric element
Implementation Method 2
Alternatively or in combination, the torque sensor may comprise a strain gauge
Implementation Method 3
The torque sensor may be configured to measure radial deformation of the first gear shaft
Data Source
AI summary
A power tool attachment part for a power tool, comprising: an elongate housing including an upper housing part and a lower housing part interconnected with the upper housing part. An input gear is configured to be connected to an output shaft of a power wrench, which input gear is arranged at a first end of the housing. An output gear has an output interface. The output gear is arranged at a second end of the housing. A first intermediate gear is arranged inside the housing and configured to transmit torque of the input gear to the output gear. The first intermediate gear is rotationally mounted on a first intermediate gear shaft. A torque sensor is configured to measure radial forces acting on the first intermediate gear shaft to thereby obtain a measure of the torque at the output gear.