What type of gear produces greater thrust forces?

Helical gears are designed with teeth that are angled relative to the gear axis, which allows them to engage gradually as they mesh. This gradual engagement leads to a more even distribution of forces across the gear teeth compared to spur gears, which have straight teeth. The inclined teeth of helical gears create axial thrust forces as they push against each other during operation. This design provides smoother and quieter operation, and the engagement over a broader surface area reduces stress concentration, which helps in handling greater thrust forces effectively.

In contrast, spur gears generate point contact and tend to create more radial forces. Bevel gears also have slanted teeth but are typically used to change the direction of the drive rather than to maximize thrust. Worm gears are designed primarily for high torque applications but do not produce significant thrust forces; they convert motion efficiently but primarily generate axial load rather than thrust. This makes helical gears the best choice when greater thrust forces are required in mechanical systems.