Power trans Flashcards
What is a gear and its purpose
A gear is a rotating machine part with “cogs” or “teeth” that project from it and mesh with similar cogs or teeth on another gear.
The purpose of gears is to transmit torque
Name the characteristics of spur gears
Spur gears are also called straight-cut gears.
These are the simplest type of gear.
They are made from a cylinder or disc with teeth projecting radially.
Edges of the teeth are parallel to axis of rotation.
These gears will only mesh properly if they are aligned on parallel shafts.
What is the relationship bewtween torque and speed
Speed of large gear is less than that of the small gear, stepped down by the gear ratio N.
Torque available is stepped up by the same factor (N) by which the speed is stepped down.
What is this and characteritics
Straight Bevel Gears
Bevel gears allow the driving shaft and the driven shaft to be offset by 90⁰.
What is this and its char
Helical Gears
The use of helical gears results in less vibration and less audible noise than gears with straight teeth.
what is this and its characteristic
Helical Bevel Gears
Combines the characteristics of bevel gears and helical
What type of gear is this and characterisitc
Rack and Pinion Gears
The rack and pinion allows circular motion to be converted to linear motion.
Teeth on the circular gear (pinion) engage the teeth on the flat bar (rack).
what gear is this and chacteristic
Worm Gears
Commonly used in applications where the load may try to move after a motor is stopped
names three different belt types
V belt, flat belt, toothed belt
