In bevel gears, the axes of the gears are at right angles to each other. Bevel gears are used to change the spatial direction of rotation.
Diagram of spiral bevel gear pair.
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The designing and modeling of equal base circle herringbone curved bevel gears
Bevel gears - tec-science
LOYAL TECHNOLOGY 1 Piece Bevel Gears Strong Hardness Angle Pinions : : Business, Industry & Science
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The Science of Bevel Gears: Principles and Applications – ZHY Gear
Screw gears (crossed helical gears) - tec-science, gears
Bevel Gears - an overview