Axle Drive Arrangement

[electrosteam]

Hi,
I have operated a small box-cab 0-B-0 electric loco for the last few years with great success, and several iterations.
Currently it has two 300W 24Vdc motors with PWM control from three 12Vdc batteries with two double reductions via toothed pulleys, matching rubber belts, layshafts and siderods.

On the last run, one of the final belts failed.
No great problem to remove the siderods, axle and layshaft to fit a new belt, but the work makes me wonder if there is a better way.

Just seeking comments from others on what they use for the drive to the axle.
- toothed belts and pulleys,
- smooth belts and pulleys,
- chain with removable link,
- meshed gears,
- linked belting,
- something else.

Currently, my thinking for the next loco is for toothed belts onto a smooth axle pulley.
The teeth would give reliable drive from the layshaft or motor, the large wrap on the axle should also be reliable.

John.

[electrosteam]

I thought vehicle timing belts were termed 'ribbed belts'.
The rubber belts I am using are the Gates XL flat style 10 mm wide having teeth at 0.2" pitch to engage matching teeth on the aluminium pulleys.

Do any others use ribbed belts, and what are the advantages ?

My current design proposes about 300 W onto each axle at about 338 RPM with a pulley about 75 mm.
If I use a metric equivalent to the XL, can anyone comment on whether the axle pulley needs to be toothed, and whether an aluminium or steel pulley would be preferable ?

John

[dfh]

Hi, In UK ribbed belts are also called poly v belts, I believe they can transmit greater power and run on smaller diameter pulleys than standard V belts or cogged V belts. They can be used on vehicles for alternator drive. Vehicle timing belts are always toothed to ensure that the timing is always correct.
I could be wrong but you may need more tension on a poly vee belt to prevent slipping than with toothed belts and pulleys.
David

[electrosteam]

David,
Thanks for clarifying the differences in the belts, I can now see what vulcan100 was saying.
I will research timing belts to see how they compare on size, price and performance.

The question of whether to use a toothed pulley on the axle may need a realistic mock-up.
My loco is now back together and I have spare belts, motors and controllers that could be used for power/speed tests of plain pulleys.

John.

[fostergp6nhp]

Poly V belts do need more tension than V belts.
Personally I would go chain and sprockets.