Gates and RoHS Compliance

RoHS is the European Union directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment 2002/95/EC.

Gates can provide declaration of compliance letters for customers concerned with the RoHS compliance status of Gates belts and hardware. To obtain a declaration of compliance letter, contact Gates Product Application Engineering by phone at +1.303.744.5800 or via email at ptpasupport@gates.com.

Belt Drives and Radiation Exposure

Exposure to gamma radiation can be detrimental to the compounds used in rubber and urethane synchronous belts. Radiation degrades belt materials much the same way excessive environmental temperatures do. The amount of degradation depends upon the intensity of radiation and the exposure time. For good belt performance, the following exposure levels should not be exceeded:

Standard Construction: 10⁸ rads

Non Marking Construction: 10⁴ rads

Conductive Construction: 10⁶ rads

Low Temperature Construction: 10⁴ rads

Gates Poly Chain Belts Power NHRA

Gates is excited to be sponsoring two of the premier NHRA drag racing teams in 2013 - John Force Racing and Don Schumacher Racing. The two teams will be fielding both funny car and top fuel racing teams in 2013.

The 2013 season sees the debut of Brittany Force in a Top Fuel car - the first time that John Force Racing has fielded a Top Fuel car. We'll be following the teams and challenges through the upcoming season. The Poly Chain belt used for the Top Fuel and Funny Car supercharger drives is a special construction that allows it to handle the extreme shock loads, torque reversals, and speeds on the unique application. The extremes of the supercharger application help us as application engineers to understand the limits of our product, and push capabilities even further. Things that we learn about harsh loading and belt performance are then used to improve belt constructions and application expertise on demanding industrial applications. There aren't many industrial applications that get from 0 to 300+ MPH in less than 4 seconds though....

Calculating Rim Speeds

You may know that our stock metal is all statically balanced to 6500 ft/min, but some of you may not know how to find out what rpm and diameter combination that equates to.  I’ll show you how.  This can be useful for not only maximum rim speeds, but also when you need to find out what rpm at which to run a head roll of a conveyor.

You need the sheave/sprocket outer diameter and RPM.  For this example, let’s use a 10” diameter and 200rpm.

Step 1, Find Perimeter.

Perimeter = 2*pi*r          or            Perimeter = pi*d

Where r = radius and d = diameter

Example: pi*10” = 31.415”

Step 2, Calculate Rim Speed

Rim Speed = Perimeter*RPM

Example: 31.415” * 200rpm = 6283 in/min

Step 3, Convert to proper units

12” = 1ft

Example 6283 in/min * (1ft/12in) = 523.59 ft/min

As always, feel free to call us if you have any questions.

If It Leaves the Ground, a Gates Belt Can't be Found

The purpose of this blog post is to expand on a previous blog regarding Aircraft Applications.

The Gates Corporation has had a long standing policy of not recommending the use of our power transmission products on aircraft, including kit, home-built or ultra light aircraft.  Whether the aircraft is FAA certified does not change this policy. This policy applies to any application where the equipment leaves the ground. A recent request serves as a great example. A customer called to receive assistance for designing a belt drive on a pump. The pump itself didn't leave the ground, but it supplied water at a high pressure to a water powered jet pack. Clearly, we could not support this customer because the application goes against our safety policy.

Only automotive and industrial belts and belt drives are sold through Gates distributors or the open market. Those belts and drives are NOT designed or made for aircraft.  DO NOT purchase Gates belts or belt drives for use on aircraft. This is a safety issue. Airplanes and cars are quite different as far as belts and belt drives are concerned. 

To emphasize this important point, do not use any Gates belt, pulley, or sprocket on a propeller-driven or rotor drive aircraft, and not with any in-flight accessory drive application or other drive in an aircraft.  For all types of applications, belt drives must be properly designed, installed, tested, and maintained.  It is impossible to inspect a belt and predict the remaining belt life. A broken belt means immediate loss of power and ability to fly! 

Feel free to contact us at ptpasupport@gates.com or 303-744-5800 if you have any questions or comments.

HP and Torque

People use the words hp and torque quite a bit, however, they don’t always understand the relationship between the two units.  I’m going to attempt to clear that up a little bit, and maybe make designing a little easier in the process.

Torque (Q) is basically a force at a distance.  If you think of a ratchet that is one foot long, and you apply 2lbs of force at the end of the ratchet, you are applying 2ft*lbs of torque (1ft x 2lbs).

Horsepower (hp) is a unit of measure of the rate at which work is done.  Let’s take the example above.  We are going to assume that applying the 2lbs of force will allow the ratchet to turn the bolt.  We count every time we make a complete circle (revolution) over a specific amount of time.  If we use minutes, we have RPM (revolutions per minute).  To calculate hp from torque and rpm you can use the following equations:

hp = (Q * RPM)/5252      This equation is when Q is given as ft*lbs

hp = (Q * RPM)/63025   This equation is when Q is given as in*lbs

You can see that hp is always a function of torque and rpm.  In the case above, if we can turn the ratchet 300 time per minute, with 2lbs of force, we are creating a huge 0.114hp.  These equations really start to become useful when you need to calculate the amount of torque that can be produced at a driven sprocket after a gearbox.  This will allow you to determine if your motor is big enough, and your reduction ratios are correct.

Diameter Differences

When asking questions about a drive, a lot of the time people take a diameter measurement to give to us.  On a synchronous sprocket, this can be a little deceptive.  There are three main diameters that are important, and this may not be obvious to the person taking the measurement.

First, if at all possible, always get a tooth count (or the part number).  Tooth count is exact, and is the best way to get you the correct answer.  If a diameter measurement is the only option, there are a few things that you need to know to get the best result.

Pitch Diameter (PD):  This is a theoretical diameter, and cannot easily be measured by hand.  However, this can be calculated.  The formula is:

(#teeth*pitch)/pi.  Pitch diameter is slightly larger than outer diameter (OD).  The diameter listed in the catalog is the PD, so if you are measuring the sprocket trying to identify the tooth count, the PD number should be slightly bigger than your OD.

OD:  Outer diameter is measured on the tooth surface.  This is the measurement we need if you can’t provide a tooth count.  Be careful when measuring this, as there is not always the tip of a tooth 180 degrees apart from one another, and you could get a measurement that is a little smaller than your actual sprocket.

Flange Diameter:  This is the one that gets people into trouble.  The flange is the largest diameter of the sprocket; it’s the part that keeps the belt from running off of the edge of the sprocket.  Not all sprockets have flanges, and sometimes the same flange is used for a couple of different sprocket sizes.  This means that if you provide us a flange diameter, we have to guess as to what sprocket you may actually be using.  Avoid measuring the flange if at all possible, but if you must, make sure that you tell us that it is a flange that you are measuring, and not the OD.