Machine Elements II Lecture Notes. Prepared by: Prof. Dr. Akgün Alsaran
Helical gear geometry
Contact ratio
Helical gear dimensions
Strength calculation of helical gears
Helical tooth forces
Examples
Machine Elements II – Helical Gears Slide Presentation DOWNLOAD PDF (Turkish document)
Related Scientific Articles
Computer-based generation of the tooth profile of involute helical gears manufactured with a pinion cutter (Turkish document)
Assoc. Prof. Dr. Cüneyt Fetvacı. Istanbul University / Faculty of Engineering / Department of Mechanical Engineering.
Effect of the Helix Angle
In helical gears, the helix angle directly affects both tooth strength and the amount of axial force generated.
Gradual Tooth Contact
Helical gears provide more gradual tooth contact than spur gears, making them run more quietly.
Balancing the Axial Load
Special thrust (axial) bearings are typically used to balance the axial force generated by helical gears.
Related Questions
In spur gears, tooth contact begins and ends abruptly, while in helical gears, because the teeth are angled, contact begins and ends gradually. This smooth transition reduces impact, producing less noise and vibration during operation.
The angled structure of the teeth generates a sideways thrust force (axial force) during rotation. Special thrust bearings need to be fitted to the shaft to handle this additional force, which spur gears don’t produce.
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