Gear selection 2

[asvipin]

I want to select gears for a gear ratio of 10. Can I get this gear ratio by using only one pair of gears. Please suggest best pair of gears.
Thanks in advance

 

[3DDave]

You can, but you might not want to. You haven't specified enough information about what the gears are going to do to make any recommendation about them.

 

[asvipin]

Its a chain drive for long travel of a mini hoist (30 kg capacity). So for desired travel speed and torque the motor speed is to be reduced by a factor of 10. The power transmitted is very small around 15 watts. I think the gear ratio is difficult to achieve with spur gear. Also it will be too small for worm and worm gear. By using multiple gears it is possible but it makes by system complex. Please suggest a simple configuration

 

[drawoh]

asvipin

A 10:1 ratio can be done in one stage of a belt, chain or gear drive. It may be a poor layout.

Do an arrangement drawing of your concept. See if it works. If you can do it in one stage, you have two gears or sprockets. If you need two stages, you need four gears or sprockets.

In the case of any sort of sprocket, make sure you have enough teeth in contact.

--
JHG

 

[tbuelna]

You can get a 10:1 reduction in an epicyclic stage, and the input/output will be coaxial.

You can use a 2 stage spur gear reduction where the motor pinion drives a compound gear, and the output gear is coaxial with the motor shaft. This will provide an output that rotates in the same direction as the motor.

A 10:1 single chain reduction will not be very compact and the smallest chain you can find might be a bit oversized for your power levels.

 

[MikeHalloran]

>>>Also it will be too small for worm and worm gear.<<<

WHAT will be too small? 10:1 is well within a worm gear set's capability. (Peugeot has used worm drive axles at ~3:1)

For parallel shafts, 10:1 in one pass is possible with gears. The only drawback is you need a big driven gear with a lot of teeth. Extra gear passes are added to save space, not because one pass can't work.

10:1 is also possible with roller chain. You may need a small idler to get enough wrap on the smaller gear.

Hoists that use wire rope or strap as the lifting element are commonly built with a modest gear pass in the drum itself. What sort of hoist mechanism are you planning to use?



Mike Halloran
Pembroke Pines, FL, USA