Self-locking Condition
Self-locking Condition - Related Videos
01:16
Self-Locking Screw
0 Views •
2023
A square-threaded screw jack is a mechanical device widely used for lifting heavy loads or applying considerable force. One of the key features that can make a screw jack more effective and reliable is its self-locking capability. A square-threaded screw jack carrying a load is considered self-locking if the screw retains its position even after the moment applied to it is removed. This occurs when the frictional force direction reverses, and the reaction force acts on the other side of the...
14:18
Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements
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Cited by 2 •
2016
A protocol to detect and automate mode locking in a pre-adjusted nonlinear polarization rotation fiber laser is presented. The detection of a sudden change in the output polarization state when mode locking occurs is used to command the alignment of an intra-cavity polarization controller in order to find mode-locking conditions.
07:25
Transfection and Mutagenesis of Target Genes in Mosquito Cells by Locked Nucleic Acid-modified Oligonucleotides
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Cited by 3 •
2010
Oligonucleotides can be used to site specifically substitute a single nucleotide of transfected target genes in both Anopheles gambiae and Anopheles stephensi cells.
06:46
Fear Conditioning
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2023
Fear Conditioning is a type of learning in which an association is established between a negative unpleasant event and a harmless stimulus. This leads to a fear of the harmless stimulus. This process is largely mediated by the amygdala, which is a brain region involved in emotions and stress reactions. Fear conditioning can be utilized in several ways to understand different aspects of learning and memory. This video presents an overview of the principles behind fear conditioning, discusses the...
02:44
Endovascular Treatment of Acute Ischemic Stroke Using the Stent Retriever-Assisted Vacuum-Locked Extraction Technique
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2025
Source: Schregel, K., et al. Optimized Management of Endovascular Treatment for Acute Ischemic Stroke. J. Vis. Exp. (2018).This video demonstrates the endovascular treatment of acute ischemic stroke using the stent retriever-assisted vacuum-locked extraction technique. A guiding sheath is introduced through the femoral artery to reach the clot. A catheter with a stent retriever secures and extracts the clot. Vascular imaging is done to confirm successful reperfusion.
FAQs
In a threaded power screw, engineers assess the relationship between lead angle and friction angle. When the lead angle remains smaller, thread contact resists reverse motion under load while still permitting driven motion in the intended direction. This comparison is central to evaluating whether a design will retain its position without back-driving.
Friction provides the resistance needed to oppose reversal, but it also increases the torque required to drive the mechanism. That added resistance can produce greater heat generation and wear during operation. Engineers therefore balance sufficient friction for stable positioning against excessive friction that could reduce efficiency and increase mechanical demands.
A self-locking arrangement can help maintain a loaded position through the thread and friction relationship, potentially reducing the need for a separate brake. This integration can simplify the positioning function in suitable mechanisms. However, the design still requires attention to driving torque, heat generation, and wear because friction performs both stabilizing and energy-dissipating roles.
An engineering evaluation begins by comparing the screw’s lead angle with its friction angle under the intended loading conditions. A lead angle smaller than the friction angle supports resistance to reverse motion. Engineers then consider the resulting driving torque and the expected effects of friction, including heat generation and wear, before selecting the arrangement.
The principle is useful wherever a mechanism must hold a load or position after the driving input stops. Examples include screw jacks, clamps, presses, hoists, and linear actuators. In these systems, the threaded arrangement can support stable positioning while limiting backward movement, which may reduce reliance on an additional braking component.
Engineers should examine whether the mechanism holds its position under load and whether it still receives adequate driving torque for operation. They also need to monitor efficiency-related consequences, particularly heat generation and wear caused by friction. These outcomes reveal whether the design achieves useful resistance to reversal without imposing excessive mechanical losses or maintenance demands.