Sawmill belts and Pulleys explained Part 1
FLEXIBLE BELTS AND SHEAVES
Flexible belt drives are used in industrial power transmission applications, especially when the speeds of the driver and driven shafts must be different or when shafts must be widely separated. The trend toward higher speed prime movers and the need to achieve a slower, useful driven speed are additional factors favoring the use of belts. Belts have numerous advantages over other means of power transmission; these advantages include overall economy, cleanliness, no need for lubrication, lower maintenance costs, easy installation, dampening of shock loads, and the abilities to be used for clutching and vari-able speed power transmission between widely spaced shafts.
Power Transmitted By Belts.
With belt drives, the force that produces work acts on the rim of a pulley or sheave and causes it to rotate. Since a belt on a drive must be tight enough to prevent slip, there is a belt pull on both sides of a driven wheel. When a drive is stationary or operating with no power transmitted, the pulls on both sides of the driven wheel are equal. When the drive is transmitting power, however, the pulls are not the same. There is a tight side tension T T and a slack side tension, T S . The difference between these two pulls
(T T .T S ) is called effective pull or net pull. This effective pull is applied at the rim of the pulley and is the force that produces work.
More tomorrow---
Tree facts you may not know
- Forest planting is one of the most cost-effective ways of reducing CO2. To remove 1 pound of CO2, planting tree costs less than 1 cent, developing more energy efficient appliances costs about 2 1/2 cents, and developing more fuel-efficient cars costs about 10 cents
- Well placed trees help cut energy costs and consumption by decreasing air conditioning costs 10-50% & reducing heating costs as much as 4-22%.
- Trees are the longest living and largest living organisms on Earth.
- One person causes about 10 tons of carbon dioxide to be emitted a year. One tree removes about 1 ton of CO2 per year. Planting 30 trees per person will remove each that person's carbon debt for the year.
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Strange new tree found in Canada!
Its been a while since I last posted an article, but its been a busy couple of months for me, I hope to start posting again soon. Anyhow I have lived in the east kootenays all my life and worked in every corner of the valley, for 25 years I have been driving past this tree on the side of the hiway, it looks different than all of the trees around it, I remember when I was a kid my dad told me " Thats the cauliflower tree, its the only one left" well I finally stoped and took a few pictures of it to try to identify it, I spent a good amount of time trying to find it on the internet but have not turned up a single tree that looks like it, Im not shure if its a special tree or not but here are the pictures, if anyone can identify it post here and let the rest of us know what it is.
Click to enlarge
The tree as it stands in the middle of a Xmas tree patch
The bark of the tree
