Wednesday, 26 February 2020, 3:26 PM
Site: IMI eLearning
Course: IMI eLearning (IMI eLearning)
Glossary: Automotive Glossary
R

Ram Pressure

Pressure caused by air of fluid movement.

Range

The difference between the highest and lowest numbers.

Range Change

(1) High and low gear ratios for an off-road or sport utility vehicle. (2) Secondary gearing in a large goods vehicle transmission gearbox that couples with the primary gears to double or treble the overall gear ratios.

Rare earth magnets

These magnets are made from substances which hold a more dense magnetic flux than regular magnets. This means more power for the weight. Rare earth magnets are always preferable although not necessary as they can be expensive.

Ratchet

A mechanism consisting of a toothed wheel, the ratchet, and a locking or actuating pawl. Used to either prevent the pawl lever or the wheel from rotating in one direct only or in some mechanisms to drive the wheel forward.

Ratio

The numerical relationship between two or more components transmitting a force or movement.

Ravigneaux Planetary Gears

An epicyclic gear set with two sun wheels and planetary gears on a common annulus.

Re-face

Term used to describe the action when the face of a valve or other component is machined.

React

To respond.

Reaction

An equal and opposite force.