Idler wheel tensioner on outside of V belt

[fergycool]

Hi,

My raw water pump bracket is a rubbish home made affair with a pedestal Jabsco pump. To tighten the belt you need to slide the pump upwards on a bracket then tighten two nuts. Needs three hands!

I'm thinking of making a bracket to hold the pump in one place, then use a idler wheel tensioner on the outside of the V belt to adjust the tension in the belt.

Is that going to be OK? I need a idler wheel on a screw to tighten it. Do such things exist?

Thanks!
Ferg

 

[lw395]

AFAIK, some vee belts are OK with idlers running on the outside, and some are not!
Would it not be better spring loaded, as is common with the polyvee belts on cars?
Or an idler pulley on the inside?

 

[fergycool]

AFAIK, some vee belts are OK with idlers running on the outside, and some are not!
Would it not be better spring loaded, as is common with the polyvee belts on cars?
Or an idler pulley on the inside?

It's pretty tight to add one on the inside. The belts are standard 13mm V belts (Green Gage ones).

 

[rogerthebodger]

Hi,

My raw water pump bracket is a rubbish home made affair with a pedestal Jabsco pump. To tighten the belt you need to slide the pump upwards on a bracket then tighten two nuts. Needs three hands!

I'm thinking of making a bracket to hold the pump in one place, then use a idler wheel tensioner on the outside of the V belt to adjust the tension in the belt.

Is that going to be OK? I need a idler wheel on a screw to tighten it. Do such things exist?

Thanks!
Ferg

No it is not OK it will damage the Vee belt the greater the angle the greater the damage.

I had mine that way the changed it to this after several belts were damaged.

 

[Avocet]

Like everything else, it's a question of degree. Conventional V belts don't like being bent "back" on themselves, it's true, but if it's only a relatively small deflection in a long belt run you can get away with it. I've had to cobble up just such a tensioner for my lathe. Pulley centres are maybe a foot apart, going round (say) 60mm diameter pulleys. In the middle of the "slack" span of belt I have the tensioner which bends the belt maybe an inch from the true straight line. I just replaced the belts after 10 years. You can get away with more if you used one of those "cogged" V belts that have notches all along the inner edge to allow them to bend more.

 

[fisherman]

I had a pot hauler working on a pair of tensioned V belts. It was fine, but the tension pulley was on the inside. An outside tensioner may capsize the belt, unless you can use multiple banded V belts. I would attempt to mount the jabsco itself on a swivel much the same as an alternator, with a long lever and threaded screw at the end for adjustment.

 

[fergycool]

I would attempt to mount the jabsco itself on a swivel much the same as an alternator, with a long lever and threaded screw at the end for adjustment.

I'm trying to avoid that as it's a lot of work in that space. But it would, by far, be the best option!