Variable diameter Pulleys Hallo Mary (a4niko) I do not know the REAL working contditions and the problem you have . I suppose you want to regulate the air suction. I would sugest you a "clever " solution . 1.Let the Ventiator run run with one pair of Pulleys. 2.Put an "T" piece in the Suctio side ,with a Damper at the free part of "T" (3rd not connected to the pipe network) 3. Open or close the Damper to adjust the flow as you wish.... Damper ajustment can be also be automated -later. If this isn not OK , then you could have a 2-speed Motor (if you want to avoid inverters ..and so on... ) I hoppe i hav helped you Nikos
Belt tension This is a very easy way of keeping the tension on your belt as long as you have a mounting plate? 1-You want to use a small pulley, preferrably one with sealed bearings. 2-You will need to use a "c" or "u" bracket that attaches to pulley 3- spring with tension bolt. Or you could send me a picture of what you have and I could help you out?
You could take the actual chain and transmission from a bike and attach it. Or you could just change the speed of the motor.
Variable diameter Pulleys - 2 Variable diameter Pulleys - 2 Hello Engineers I think we do not have understood the Project. Suppose you have 2 Double Diameter Pulleys First D1=50/D1a=100 mm , and Second D2=100 /D2a=50 mm Combination A Driving Pulley D1=50 mm Driven Pulley D2=100 mm Distance o Axes A = x Motor Speed = 1200 rpm (e.g.) Ventilator speed = 600 rpm Combination B Now we change Driving Pulley D1a=100 mm Driven Pulley D2a=50 mmm Distance o Axes A = x (We do not need Belt Tension ...!) Motor Speed 1200 rpm Ventilator speed = 2400 rpm A real problem is the Efficiency o Ventilator , Staic pressure , and Flow( CFM) at 600 or 2400 rpm . Here we need the Ventilator Characteristic Curves from Constructr's Manual.... A calculation can be done for getting the Second - or First â€“Diameter combination alternatives so that the Distance of Axes remains constant = X Mary(a4niko) asked something not to specific..So She is getting not Specific answers... The Engineers are giving Answers and Solutions, and this is encouraging... Nikos
To change from single to dual revolution using belt & pully you need just two pair pullys (one pair on the motor and one pair on fan). by choosing the appropriate diameter, you can change the speed by moving the belt from one pair to another pair of theese pullys without changging the speed of motor. to evaluate the efficiency of fan you can verify using the graph of fan performance Jupe
Dear Engineers Thanks alot, i am so happy to see your answers My profession is industrial engineering and beacause of this i cant explain well, and i need to consult with my friend about your suggestion, You give me Good suggestion but Let me explain much : I know with calculating numbers for the size of pulley we wont need belt tensioner. but the problem is after calculating we face with high weight pulley so it needs more powerfull motor and it isnt possible to use a powerfull motor then the only solution that we thaught is belt tensioner but belt tensioner will not work well we are working on it .... i will back with more detail Best regards Mary
belt driven motor As I understand your problem is the weight of the pully. I'm not sure if the weight is the real problem. I think the problem is because you drive the fan (by chnagging the speed) over the limit of power of the motor. You need to check the characteristic of fan you have (relation between speed and power) so you can design or regulate the speed within these limit. Jupe
Hi Jupe No its not under the limit i mean if there is something to just regulate the belt(tension) the problem will be solved. Any way Thank a lot for your reply Mary
No, i mean not to regulate the tension of the belt but to choose the rotation or speed of the fan. Because as you know the power needed to drive fan it is depend on the design of the blade and the rotation/speed. more speed more power needed. so it is need to check whether the power needed is over the power of the motor. Jupe