Understanding Gear Reduction: How to Achieve Lower Angular Velocity in Gears

In summary: However, gears with an even number of teeth will generally have a shorter lifespan than gears with an odd number of teeth.
  • #1
dislect
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hi everyone!

i was wondering how gear reduction is done besides connecting a small gear to a larger gear (radius speaking)?
In my problem i have a gear - radius:5cm, angular velocity: 1000rpm
I have a second gear - radius:5 cm, anguler velocity required: 1 rpm

How do i make this happen? do i play with the numer of "teeths" on each gear, say that the first has 1 teeth and the second has 1000?

Thanks
 
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  • #2
The smallest pinions rarely ever have fewer than 12 teeth to avoid under cutting of the teeth during forming.

In order to achieve a particular gear ratio, it is necessary to find a number pair, a number quad (for two stage gearing), a number hex (for three stage gearing), etc. which in combination will give the required gear ratio. There are definite procedures for doing this, but most people simple start guessing. Only in rare circumstances is it required to hit a specific gear ratio with great accuracy.
 
  • #4
Keep in mind also that if the gears are directly meshing, they have the same tooth pitch. This means for a given diameter (5cm for example) the gears would have to have the same number of teeth. To accomplish gear reduction in this case you have to transition to a smaller pitch.
 
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  • #5
How much power do you have to transmit?
 
  • #6
Gears should have an odd number of teeth as well to even out wearing.
 
  • #7
"Gears should have an odd number of teeth as well to even out wearing."

Actually, this is not quite correct. The requirement is that in any individual mesh, the tooth numbers should be relatively prime. This means that there must be no common factor between the tooth numbers. If, for example one of the tooth numbers is a prime number such as 57, then the other tooth number could be any number and the condition of being relatively prime is still met since there would be no common factor between the prime number 57 and the second number which may be even or odd.
 

1. What is gear reduction and how does it work?

Gear reduction is a mechanical process that involves using gears to decrease the speed and increase the torque of a rotating system. This is achieved by connecting two or more gears of different sizes, with the smaller gear (known as the pinion) driving the larger gear (known as the gear). As the pinion rotates faster, it transfers its rotational energy to the gear, resulting in a slower rotation but with more force or torque.

2. What are the different types of gear reduction systems?

The three main types of gear reduction systems are spur gears, helical gears, and planetary gears. Spur gears are the most common and use straight teeth on parallel shafts to achieve gear reduction. Helical gears use angled teeth on parallel or intersecting shafts for a smoother and quieter operation. Planetary gears use multiple gears in a circular arrangement to achieve high gear reduction ratios.

3. What factors should be considered when selecting a gear reduction system?

When selecting a gear reduction system, factors such as the required gear ratio, operating speed and torque, efficiency, noise level, and space limitations should be taken into consideration. The type of application and the environment in which the gear reduction system will be used should also be considered.

4. How is gear reduction calculated?

Gear reduction is calculated by dividing the number of teeth on the driven gear by the number of teeth on the driving gear. This ratio is known as the gear ratio. For example, if a gear with 20 teeth is driving a gear with 40 teeth, the gear reduction ratio would be 2:1. This means that for every two rotations of the driving gear, the driven gear will rotate once.

5. What are the advantages of using gear reduction systems?

Gear reduction systems offer several advantages, such as increasing torque and reducing speed, which is beneficial for applications that require more force or power. They also allow for the use of smaller and more compact motors, reducing overall system size and cost. Additionally, gear reduction systems provide precise and reliable power transmission, making them suitable for a wide range of industrial and consumer applications.

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