Power Tool Spindle Pre-Centering for Reliable Lock Engagement
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Solution Overview
Problem
Conventional locking units in hand-held power tools require elaborate orientation of the spindle unit to transition from an unlocked to a locked state, and there is no guarantee that the spindle unit is properly set in the locked state.
Innovation Solution
The spindle unit is pre-centered with respect to the locking unit using cogging torques, magnetic forces, and mechanical alignment to facilitate a simple and reliable transition to a locked state without additional orientation, utilizing magnetic resistance and mechanical contact to engage the locking unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional locking units are used without pre-centering, then the locking mechanism is simpler in design, but the spindle unit requires elaborate orientation to transition from unlocked to locked state
Solution Approach 1:
The drive unit is pre-centered with respect to the locking unit by means of a magnetic force, preferably by means of cogging torque, before the locking operation is initiated. This preliminary positioning action ensures that the spindle unit is already in the correct orientation when the locking operation begins, eliminating the need for elaborate orientation during the locking transition.
Solution Approach 2:
The patent replaces purely mechanical orientation mechanisms with a magnetic field-based pre-centering system. The magnetic force, generated through cogging torque between the rotor and stator, substitutes for complex mechanical alignment mechanisms, reducing overall device complexity while improving ease of operation.
2Measurement precision
If the spindle unit is pre-centered using magnetic forces and cogging torque, then the orientation precision is improved, but the device complexity increases
Solution Approach 1:
The drive unit's own magnetic field and cogging torque, which are already present during motor operation, are utilized for self-centering purposes. The rotor and stator magnetic fields serve dual functions: both for driving the spindle and for pre-centering it relative to the locking unit, eliminating the need for separate centering mechanisms.
Solution Approach 2:
The magnetic field system performs multiple functions simultaneously: it provides the driving force for spindle rotation and also provides the pre-centering force for accurate positioning relative to the locking unit. This multi-functionality reduces device complexity while maintaining high orientation precision.
3Ease of operation
If the locking unit is designed to lock without further orientation, then the ease of operation is improved, but the reliability of achieving proper locked state may be compromised
Solution Approach 1:
The magnetic pre-centering action is performed before the locking operation, ensuring that the spindle unit is already in the correct orientation when the locking unit engages. This preliminary positioning ensures that the subsequent locking operation can proceed without further orientation while reliably achieving the proper locked state.
Solution Approach 2:
The pre-centering mechanism provides a buffer or cushioning effect that compensates for any potential misalignment before the locking operation begins. This ensures that even with variations in manufacturing or assembly, the locking unit will reliably engage in the correct position without requiring elaborate orientation during the locking operation itself.
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 that the spindle unit is accurately positioned for locking, reducing the need for manual alignment and minimizing the risk of damage or rattling, while maintaining a compact and secure locking mechanism.
Implementation Method 1
the drive unit, in particular the spindle unit, may be oriented, in particular may be pre-centered, with respect to the locking unit, in particular by means of a magnetic force, preferably by means of cogging torque
Implementation Method 2
the drive unit, in particular the spindle unit, may be oriented, in particular may be pre-centered, with respect to the locking unit, in particular by means of a magnetic force
Implementation Method 3
When oriented by means of a mechanical force, the drive unit, in particular the spindle unit, may be turned by means of a contact or a force effect by the locking unit
Data Source
AI summary
The invention disclosure relates to a hand-held power tool with a drive unit which comprises a spindle unit, and with a locking unit for locking a spindle unit which is mounted, in particular, rotatably about a drive axis. It is proposed that the drive unit, in particular the spindle unit, may be oriented, in particular may be pre-centered, with respect to the locking unit, in particular by means of a magnetic force.