alanchow03 發表於 2012-1-2 22:34
大家都係 ratio 4.0, 大家都係64 pitch,有冇話邊樣著數d?
88/22
Found the following, looks like "efficiency" is the main effect.
http://www.societyofrobots.com/mechanics_gears.shtml
" Gear Efficiency Unfortunately, by using gears, you lower your input to output power efficiency. This is due to obvious things such as friction, misalignment of pressure angles, lubrication, gear backlash (spacing between meshed gear teeth between two gears) and angular momentum, etc. Different gear setups, different types of gears, different gear materials, and wear and tear on the gear, will all have different efficiencies. The possible combinations are too big to list, so I will give you an estimated efficiency to expect with each gear type below. You can also find a much more exact efficiency by looking up the datasheet on the gears you are using.
For example, suppose you use two spur gears, you would typically expect efficiency to be around ~90%. To calculate, multiply that number by your Velocity_New and Torque_New to get your true output velocity and torque.
if (from above example)
Gearing ratio = 2/3
Torque * 2/3 = 6.7 lb-in
Velocity * 3/2 = 150rps"
MAYBE
- smaller, lighter gears (88/22) will have less momentum, less energy lost to carry gear rotation, perhaps more efficient,
- but smaller, lighter gears (88/22) may have more frictional lost, due to less number of gear transferring energy.
So, not sure , if any big differences after all....

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