What is the definition of "spiral angle"?
The angle at which spiral bevel gear teeth are set from the gear shaft axis. The spiral angle of most bevel gears is 35 degrees.

Learn more about spiral angle in the class Gear Applications 245 below.


Mechanical Systems Training


Class Information
Tooling U classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
Class Name:Gear Applications 245
Description:This class discusses various types of gears used in industry, including information on how gears are used, maintained, and classified.
Prerequisites: 560105  560110  560120 
Difficulty:Intermediate
Number of Lessons:18
Language:English, Spanish

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Below are all the competencies and job programs that contain the class Gear Applications 245. Job programs are our traditional class lists organized according to common job functions. Competencies are our latest job-specific curricula that help tie online learning to practical, hands-on tasks.

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Competencies


Class Outline
  • Objectives
  • What Is a Gear?
  • Gear Materials
  • Shaft Orientation
  • Spur Gears
  • Helical Gears
  • Helical Gear Variations
  • Bevel Gears
  • Bevel Gear Variations
  • Worm Gears
  • Rack and Pinion Gears
  • Planetary Gear Trains
  • Enclosed Gear Drives
  • Gear Failure
  • Gear Maintenance
  • Gear Selection
  • Gear Safety
  • Summary
  
Class Objectives
  • Explain how gears are used to transmit power.
  • Describe various materials used to make gears.
  • Explain how shafts are used with gears to transmit power.
  • Describe features of a spur gear.
  • Describe features of a helical gear.
  • Identify variations on the helical gear form.
  • Describe features of a bevel gear.
  • Identify variations on the bevel gear form.
  • Describe features of worm gear drives.
  • Describe features of a rack and pinion system.
  • Identify components of a planetary gear train.
  • Describe features of enclosed gear drives.
  • Identify signs of gear failure.
  • Describe practices for maintaining gears.
  • List factors influencing gear selection.
  • Identify safety hazards for working with gears.

Class Vocabulary

Vocabulary TermDefinition
alloy steel A steel containing another material that is added intentionally to improve certain properties of the metal.
aluminum alloy A silvery white metal that is soft, light, and has a high strength-to-weight ratio.
automatic transmission A complex transmission that does not require the operator to shift gears in order to change the speed and torque of mechanical energy.
axis An imaginary straight line that passes through the center of an object. A gear may have an opening at its axis through which a shaft can be inserted.
belt drive system A system consisting of a belt and at least two fixed pulleys that is used to transmit motion.
bevel gear A type of gear with cone-shaped teeth cut at an angle. Bevel gears are often used in angular gear trains.
breakage The fracture of part or all of a gear tooth caused by excess load and gear stress.
carbon steel Steel that is made up of iron and carbon, without any additional materials.
chain drive system A system consisting of a chain and sprockets that is used to transmit motion.
conical Cone-shaped, with a cylindrical base and pointed tip. The teeth of some bevel gears are conical.
corrode To deteriorate the useful properties in a material due to oxidation.
corrosion The gradual chemical attack on a material by atmosphere, moisture, or other agents. Some chains are designed to resist corrosion.
cylindrical configuration A worm gear drive configuration that uses a cylindrical worm to mesh with a cylindrical helical gear. Cylindrical configurations offer high speed reduction ratios but can be used only with light loads.
double helical gear A type of helical gear with two sets of teeth cut at opposing angles, separated by a groove that runs around the center of the gear. Double helical gears are used to provide smoother operation and avoid side loads.
double-enveloping configuration A worm gear drive configuration that uses an hourglass-shaped worm with curved teeth to wrap around part of the worm gear. This configuration provides the highest amount of tooth contact and can carry the greatest amount of load.
drip-feed system A type of lubricant delivery system that includes a small reservoir of lubricant connected to pipes that distribute the lubricant to machine parts.
drive gear The gear that receives energy from a power source, such as an electric motor. A drive gear transmits power to a meshing driven gear to perform work.
driven gear The gear that receives motion from the drive gear on a machine. Driven gears often turn tools or components.
efficiency A measure of the work output of a system versus the total work supplied to it.
enclosed gear drive A system of assembled gears encased by a housing that transmits mechanical energy from a prime mover to an output device, also known as a gearbox.
epicyclic gear train A gear train that consists of one or more outer gears rotating around a central gear. Epicylic gear trains are also known as planetary gear trains.
ferrous metals Metals that contain iron. Ferrous metals are commonly used to make gears.
gear A round or cylindrical mechanical component with teeth, used to transmit power. Gears are designed to intersect with one another and can alter the speed, torque, or direction of mechanical energy.
gear train A system of gears used to transmit rotary motion from one part of a mechanical system to another.
gearbox An enclosed system of assembled gears that transmits mechanical energy from a prime mover to an output device, also known as an enclosed gear drive.
gradual wear A type of gear failure that involves the removal of material from the surfaces of the gear teeth. Gradual wear can be reduced through the use of lubricants.
hardness A material's ability to resist penetration, indentation, or scratching. Hard materials tend to be very strong and resistant to wear.
helical gear A type of gear with slanted teeth. Helical gears are quieter than spur gears, but they are more expensive and produce side loads.
helix angle The angle between the axis of a helical gear and an imaginary line that is tangent to the gear tooth. Helix angles can vary in size from 0° to 90 degrees.
herringbone gear A type of gear that has angled teeth in the shape of a letter "V." Herringbone gears resist side loading but are expensive to produce.
idler gear A gear that is used to keep the direction of motion consistent between a drive gear and a driven gear.
input shaft The rotating shaft that receives power from the power source and introduces it into a mechanical system.
internal gear A circular gear with teeth that face inward, used to mesh with planet gears in a planetary gear train. Also known as a ring gear.
involute curve The path determined by tracing a point on a line that is unwound from a circle.
left-hand helical gear A helical gear with teeth that lean to the left when the gear is placed on a flat, horizontal surface.
linear motion Motion that takes place along a straight line.
lockout/tagout A method of protecting employees from accidental machine startup through proper locking and labeling of machines that are undergoing maintenance.
lubricant A substance used to reduce friction between two surfaces in relative motion. Oil and grease are common industrial lubricants.
lubrication The act of applying lubricant to machines. Lubrication reduces friction and wear between mechanical components.
mechanical advantage The difference between the applied force and the work accomplished. Mechanical advantage allows machines to perform more work with less effort.
meshing The action of interlocking with another object. Meshing gears are used to transmit mechanical energy.
miter gear A type of bevel gear used in pairs with intersecting shafts at 90° angles. Both the driving gear and driven gear in a miter gear pair have the same diameter, same number of teeth, and a mechanical advantage of 1.
nip point The point where two gears mesh, which can pinch or crush fingers or other body parts.
nonferrous metals Metals that do not intentionally contain iron.
nonmetallic materials Materials that are not made of metal, such as wood and plastic. Nonmetallic materials can be used to make gears, though they are not as common.
open gearing Gears in an unassembled form.
output shaft The rotating shaft that receives power from the mechanical system and transfers it to the output source.
personal protective equipment Safety equipment that a person wears or uses to prevent injury in the workplace. Personal protective equipment is abbreviated as PPE.
pinion A circular gear used in a rack and pinion system to produce linear motion. As the pinion turns, the flat rack slides in a linear direction.
pitch A property used to classify gears. Pitch usually refers to the number of gear teeth in one inch of the gear's pitch diameter.
pitch diameter The diameter of a gear's pitch circle. A gear's pitch diameter can be determined by measuring from the top of one gear tooth to the bottom of the opposite gear tooth.
pitting The corrosion of a metal that takes place in specific locations on a workpiece or component.
planet arm A moveable arm that rotates around the sun gear on which planet gears can be mounted.
planet gear An outer gear in a planetary gear train that rotates around the sun gear. A planet gear can be mounted on a moveable planet arm that also rotates around the sun gear.
planetary gear train A gear train that consists of one or more outer gears rotating around a central gear. Planetary gear trains are also known as epicyclic gear trains.
plastic flow A gear failure condition in which the gear teeth deform due to heavy loads.
pressure angle The angle made by the sides of a gear tooth as they incline toward the top of the gear.
rack A flat bar with teeth used in a rack and pinion system to produce linear motion. As the circular pinion turns, the rack slides in a linear direction.
rack and pinion A pair of gears used to convert rotary motion into linear motion. A rack and pinion consists of a circular gear, or pinion, that meshes with a flat-toothed bar, or rack.
right angle An angle that measures exactly 90 degrees.
right-hand helical gear A helical gear with teeth that lean to the right when the gear is placed on a flat, horizontal surface.
ring gear A circular gear with teeth that face inward, used to mesh with planet gears in a planetary gear train. Also known as an internal gear.
rotary motion Spinning or turning motion that takes place around an axis, without a change in linear position.
shaft In a mechanical system, a cylindrical bar used to support rotating components or to transmit power or motion by rotation.
side load A force that occurs when gears are meshed together at an angle. Side load can lead to deflection and wear.
single-enveloping configuration A worm gear drive configuration that uses a gear with curved teeth to wrap around part of the worm. This configuration provides more contact between the worm and worm gear teeth and can carry more load.
skew tooth gear A type of bevel gear with teeth that are straight and cut at an angle to the axis of the gear shaft. Skew tooth gears can carry more load than straight bevel gears and are generally made in large sizes.
spalling A severe form of pitting that occurs when large pits develop over a considerable area of the gear.
speed The amount of distance an object travels in a given period of time. Speed is used to measure both linear and rotational movement.
speed increasers A gearbox used to increase the speed of mechanical energy while decreasing the torque. Speed increasers are not used as often as speed reducers.
speed reducer A gearbox used to reduce the speed of mechanical energy while increasing the torque. Worm gear drives are often used in speed reducers.
speed reduction A process during which the speed of mechanical energy is reduced during power transmission. Speed reduction increases the torque of mechanical energy and is often accomplished with a worm gear drive.
spiral angle The angle at which spiral bevel gear teeth are set from the gear shaft axis. The spiral angle of most bevel gears is 35 degrees.
spiral bevel gear A type of bevel gear with conical and curved teeth, designed for smooth operation. The teeth of spiral bevel gears have a spiral angle.
splash lubrication A type of lubrication used in enclosed gear drives. In splash lubrication, the gear tooth dips into a tray of lubricant and transfers the lubricant to the meshing gear as it rotates.
spur gear A type of gear that has straight, flat-topped teeth set parallel to the shaft. Spur gears are the most common type of gears used in industry.
stainless steel An alloy steel that is designed to resist corrosion.
straight bevel gear The basic bevel gear, which has tapered teeth that are widest at their outer part. Straight bevel gears are cost-effective when transmitting power between shafts at right angles.
sun gear The central gear in a planetary gear train around which the planet gears rotate.
surface fatigue A gear failure condition in which small pieces of metal have been removed from the gear, leaving indentations, or pits, in the surface.
titanium alloy A metal containing titanium, which is a silver-gray, strong, and lightweight metal known for its corrosion resistance.
torque A force that produces rotation. Gears can transmit high levels of torque.
toughness The ability of a material to withstand forces or sudden impacts that attempt to break it.
wear The gradual removal of material on a surface caused by contact between microscopic peaks on surfaces in motion.
worm A cylindrical, screw-shaped shaft that is used with a worm gear to transmit motion.
worm gear A gear with teeth that mesh with the screw-like threads of a worm to transmit motion.
worm gear drive A gear drive consisting of a long, cylindrical device with a spiraling groove that intersects with the teeth of a wheel-like gear. A worm gear drive is used to transmit motion between nonintersecting perpendicular shafts, and the cylindrical "worm" is always the drive gear.
wrap point An exposed rotating shaft with the potential to become caught on clothing, pulling a person toward the machinery and potentially causing injury.
Zerol bevel gear A type of bevel gear with curved teeth and a 0° spiral angle. Zerol bevel gears provide smooth and quiet operation, but they produce side loads.