Definition

Noun: A worm wheel is a specific type of gear, typically a toothed wheel, designed to mesh with the threaded shaft of a worm (a gear in the form of a screw). This pairing creates a worm drive, which is used to achieve high reduction ratios and to transmit motion between non-intersecting, perpendicular shafts.

Usage

The term "worm wheel" is used in mechanical and engineering contexts to describe the gear component that is driven by a worm. It is the counterpart in a worm gear set. - The worm wheel in the steering system provides the necessary reduction for easy handling. - For the conveyor to move slowly, a large worm wheel is paired with a single-threaded worm.

Advanced Usage

• Design Considerations: The efficiency and torque capacity of a worm drive depend heavily on the material and tooth geometry of the worm wheel, which is often made from a softer material like bronze to reduce wear on the steel worm.
• Irreversibility: In many configurations, the worm can drive the worm wheel, but the worm wheel cannot drive the worm, a feature known as self-locking. This is a critical safety feature in applications like hoists and lifts.

Variants and Related Words

• Worm Gear: This term can refer specifically to the worm wheel itself or, more commonly, to the entire assembly consisting of both the worm and the worm wheel.
• Worm Drive: Refers to the complete mechanical system comprising the worm and the worm wheel.
• Worm Shaft: Another term for the worm (the threaded screw that drives the wheel).

Synonyms

• Worm gear (when referring specifically to the wheel component)
• Driven gear (in the context of a worm drive set)

Related Phrases

• To mesh with a worm: Describes the primary function of the worm wheel.

Noun

1. gear with the thread of a worm