Hydraulic Nut Clamping with Torque-Limiting Clutch
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Solution Overview
Problem
Existing screw clamping devices with hydraulic clamping cylinders face challenges in preventing excessive tightening forces during the screwing or re-tightening of threaded nuts, as they rely on correct user adjustments and torque wrench calibration, which is not always guaranteed, and require complex device technology for electrical solutions.
Innovation Solution
Incorporating a torque-dependently operating clutch within the gear arrangement, such as a friction slip clutch, that limits torque above a specific threshold, ensuring that maximum values are not exceeded, independent of user handling and eliminating the need for specific torque wrenches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a manual torque wrench is used for screwing on the threaded nut, then the trigger value can be pre-adjusted to prevent excessive tightening, but the same torque wrench is also needed for screwing the exchange bushing requiring additional calibration checks
Solution Approach 1:
The clutch mechanism automatically limits the torque to the predetermined maximum value during the screwing operation. The system serves itself by mechanically preventing excessive tightening without requiring external monitoring or adjustment by the operator, thus eliminating the need for torque wrench calibration checks
Solution Approach 2:
The manual torque wrench is replaced by a mechanically operated clutch that automatically limits torque. This substitution eliminates the need for electrical controls, sensors, or complex calibration procedures, providing a purely mechanical solution that is both reliable and simple to operate
2Reliability
If a torque wrench with pre-adjusted trigger value is used, then excessive tightening can be prevented, but it cannot prevent torque that exceeds the specific torque
Solution Approach 1:
The clutch mechanism automatically limits the torque to the predetermined maximum value during the screwing operation. The system serves itself by mechanically preventing excessive tightening without requiring external monitoring or adjustment by the operator
Solution Approach 2:
The torque-limiting function is extracted from the complex electrical control system and implemented as a separate, standalone mechanical clutch mechanism. This extraction simplifies the overall system by removing the need for electrical sensors, control units, and power supplies while maintaining the torque limitation function
3Reliability
If an electric motor with power control monitoring is used to screw on the threaded nut, then excessive tightening moments can be prevented, but the device technology becomes complex requiring separate electrical drive and control devices
Solution Approach 1:
The electrical motor drive and control system is replaced by a purely mechanical clutch mechanism. The clutch limits torque through mechanical friction and spring pressure, eliminating the need for electrical components, sensors, and control electronics while achieving the same torque limitation function
Solution Approach 2:
The mechanical clutch system is self-regulating, using spring pressure and friction to automatically limit torque. The system requires no external power source, control signals, or monitoring devices, making it inherently simpler and more reliable for torque limitation
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 torque-dependently operating clutch effectively prevents excessive forces during screwing or re-tightening, ensuring reliable operation without requiring precise user adjustments or complex electrical drives, allowing simpler manual tools to be used safely.
Implementation Method 1
a torque-dependently operating clutch which is a component of the gear arrangement by means of which the threaded nut is screwed on. For example, this clutch may be a friction slip clutch which slips above a specific torque threshold.
Data Source
AI summary
A clamping device for a screw connection, provided with a threaded bolt and a threaded nut, has a support tube surrounding the threaded nut, a cylinder housing arranged in an extension of the support tube, a piston movable in the cylinder housing by hydraulic pressure, an exchange bushing axially entrainable by the piston and provided with an internal thread for screwing the exchange bushing to the threaded bolt, and a follower element arranged inside the support tube and frictionally or with form fit connectable to the threaded nut. A drive element is rotatably mounted outside the support tube and provided with a tool surface for applying a hand tool. A gear arrangement is located between the drive element and the follower element. The gear arrangement has a clutch operating as a function of torque to prevent reliably excessive forces when the threaded nut is re-tightened and/or screwed on.