Estimating Horsepower Loads for Pumps

The power requirements for pumps should always be obtained from manufacturers if possible, but this may not always be feasible when quick field estimates are needed. The following equation can be used to estimate the power required to drive pumps:

Estimate the pump power requirement by dividing horsepower calculated above by the pump efficiency. An efficiency of approximately 70% can be used for centrifugal pumps, and approximately 80% for vane and gear pumps. Efficiency of reciprocating pumps can  vary significantly depending on pressure and stroke length.  Approximate efficiencies are included in the following table:

This approximation for pump power requirements can be used for quick estimations, or when accurate data cannot be obtained from pump manufacturers. For further information, or for assistance with a belt drive selection contact Gates Product Application Engineering at ptpasupport@gates.com or 303-744-5800.

BIRD™: Belt Installation and Rotation Device

When you’re in charge of safety, you’re in charge of protecting people’s lives. Especially in highly volatile environments like oil drilling, mining, construction, and manufacturing. One small oversight could shut down your operation—and cost you millions in lost production, downtime, or even someone’s life. At Gates, we take safety seriously.


That is why Gates has introduced the BIRD™, the Belt Installation and Rotation Device, which is a switchable magnetic clamp equipped with permanent magnets and is designed for attachment (by hand) to metallic sheaves and sprockets.

The BIRD is a specially designed, tightly compacted device, which creates a magnetic field that develops an incredible attractive force on ferromagnetic materials.




And just as the BIRD is a tool for safety, Gates recommends practicing safety when using this device. The BIRD may only be used to rotate metallic sheaves and sprockets. Proper use includes adherence to the start-up, operating, environment, and maintenance conditions specified by Gates. The user bears sole responsibility for understanding this operating manual as well as for the proper use and maintenance of the BIRD.


Please contact Gates Product Application Support at 303-744-5800 or ptpasupport@gates.com if you have any questions prior to using this device.

Calculating Proper Belt Length

We are often contacted to calculate the belt length of a specific drive given the center distance, and pulleys sizes are known.  Of course, we are glad to help in any way possible but if this calculation is needed after hours, or a phone is not readily available to you, it can be made through the equation below.

Where:

Lp = Belt pitch length (inches)

C = Center distance (inches)

D = Large pulley diameter (inches)

d = Small pulley diameter (inches)

For additional information on this or any other topic please contact Gates Product Application Engineering by phone at 303-744-5800 or by email at ptpasupport@gates.com.

Not All Sprockets Have Flanges

Did you know that not all sprockets have flanges? In belt drive systems Gates typically only recommends the smaller sprocket to have flanges on both sides.  This is to account for any belt tracking issues that may occur if alignment between the sprockets is slightly off.  When misalignment becomes worse, the belt tends to track in one direction rather than remain neutral on the sprocket.

Flange Cutoffs

Belt	Grooves
8MM Poly Chain	90à
14MM Poly Chain	90à
2MM PowerGrip GT2	62à
3MM PowerGrip GT2	48à
5MM PowerGrip GT2	80à
5MM PowerGrip GT2 AL	36à
8MM PowerGrip GT2	90à
14MM PowerGrip GT2	90à
3MM PowerGrip HTD	50à
5MM PowerGrip HTD	36à
20MM PowerGrip HTD	112à
MXL	72à
XL	32à
L	60à
H	60à

Ventilation for Belt Drives

Increasing ventilation around belt drives can help reduce belt operating temperatures in applications with high ambient temperatures, or on applications operating in enclosures. This can be accomplished by adding vents to belt guards, by providing a cooler external air source, or by even adding fins to sheaves.

V-Belts and Low Temperature Operation

In extremely low temperature operations, the rubber material in V-belts becomes stiff. At sufficiently low temperatures, the rubber will actually reach a glass point, where (as the name implies) the rubber is hard and will shatter like glass if it is bent.

This is an extreme condition but approaching this state the rubber will go through various degrees of stiffness. As long as a drive is in operation, the heat generated through drive friction and bending will increase the internal belt temperature and maintain belt flexibility in temperatures well below the normally accepted minimum operating temperature. Trying to immediately transmit a load through a belt which has taken a cold set can cause belt failure because the belt is too rigid to bend.

Options to Reduce Overhung Load on Gear Reducers and Gearboxes

If calculated overhung loads are larger than those recommended by a gearbox manufacturer, there are three possible options that can be used to reduce overhung load:

1) Increase the diameters of the sprockets or sheaves on the drive.
2) Move the sheave or sprocket inboard, thereby moving the overhung load closer to the reducer.
3) Use a belt type with a smaller overhung load connection factor (and, therefore, less total operating tension).

Synchronous Belts vs. Ball Screws

From the design, construction, and first-cost standpoint, a synchronous belt drive can have distinct advantages over a ball screw in certain applications:

 - Significantly lower first cost
 - No lubrication or maintenance required
 - Clean running drive
 - Drive length design flexibility

Idler Bushings

Some belt drives require the use of an idler sprocket whether it’d be for tensioning or achieving sufficient belt wrap.

Gates does offer a handful of idler sprockets assemblies, however depending on the pitch and the width of the belt, there can be few options.

Gates also offers a number of idler bushings (see below) to allow for more flexibility when choosing idler sprocket tooth counts and widths. We offer idler bushings in both QD and TaperLock styles. Both assemblies are compatible with our idler bracket options.

If you are in need for a larger idler sprocket or have an old sprocket you want to reuse as an idler, our idler bushings may be for you.

For additional information on this or any other topic please contact Gates Product Application Engineering by phone at 303-744-5800 or by email at ptpasupport@gates.com.

Misalignment

Maintenance technicians may not always find it practical or possible to accurately calculate the total misalignment in a system while determining if it is in acceptable alignment. It is also difficult to visualize small fractions of an angle such as 1/2 and 1/4 degrees.

These can be more clearly illustrated with the following rules of thumb:

For v-belt drives, 1/2-degree angle = approximately 1/10-inch per foot between the drive shafts.

For synchronous, 60-degree angle, and V-ribbed drives: 1/4-degree angle=approximately 1/16-inch per foot between the drive shafts.

These rules can be used to estimate the amount of angular and parallel misalignment visually rather than having to calculate actual numerical values.

Alignment, Tracking, and Flanges

If  one side on a belt wears faster than the other, a tracking problem where the belt is riding against a sprocket flange may exist. This condition is typically caused by misalignment. In the most severe cases with heavily loaded drives, side thrust forces can actually push off the pulley flanges. 

If this type of belt wear is seen, or wear varies across the belt width, check the drive alignment and adjust as necessary to achieve proper alignment.

Belt Drive Inspection and Symptom Analysis

Gates recommends the following steps when inspecting a synchronous belt drive system:

With the power shut off, locked and tagged, and the machine components in safe positions, remove the drive guard and inspect the belt and sprockets for signs of unusual wear or damage.

Symptoms such as excessive belt edge wear, tooth shear, belt cracking and tensile break may indicate the need to correct alignment or to adjust tension to the correct values.

Poly Chain GT Carbon for Food Processing Operations

For high torque applications, food processors can use Poly Chain GT Carbon belts with carbon fiber tensile cords.   Carbon fiber tensile cords provide excellent resistance to moisture and chemicals, and polyurethane stands up well to most cleaners and sanitizers. This belt offers a number of properties that make it highly suitable for food processing operations, including:
 -Excellent resistance to oils, fats, fruits, juices, vegetables, dairy products, tomatoes, wine and vinegar
 -Good resistance to food industry soils and chemicals
 -Good resistance to high-pressure wash-down sprays
 -Excellent abrasion resistance
 -Operating temperature range of -65 degrees to +185 degrees Fahrenheit

Belt Drive Inspection

For critical drives a quick visual and hearing inspection should be performed periodically. A visual and hearing inspection consists of the following three items:

1. Look and listen for unusual noise and vibration while observing the drive.
2. Inspect the guard for loose parts and damage. Make sure it is clean. Any accumulation of foreign material on the guard acts as insulation and could cause excessive heat buildup in the drive.
3. Look for oil and grease contamination that could degrade the material components of a belt.

Energy Savings with Synchronous Belts

Converting V-belt drives to synchronous belt drives can reduce energy usage.

To estimate the number of kilowatt-hours saved by using synchronous belt drives rather than V-belt drives, the following calculation can be used:
KWH= (motor hp x hours/year x .746 x.05)/motor efficiency

where constant .746 is the conversion factor from hp to KW and .05 is the estimated 5% energy savings gained by converting to synchronous belt drives.

Washdown Applications

Washdown applications can present challenges for drive systems. Rubber belts typically stand up well to washdowns with alkaline detergents. Organic solvents and strong acids used as sanitizers can attack the drive components, so one must exercise care when using these types of sanitizers. Exposed tensile cords along the sides of the belt can wick moisture into the belt over time, however, so maintenance personnel should inspect belts for wear regularly. Gates Poly Chain belts typically perform well in washdown environments and are excellent roller chain replacements.

Gates MachineWorks

Gates can provide power transmission hardware solutions for all types of non-stock bushings, sheaves, and sprockets. 

Contact the MachineWorks department to review and quote your specialty hardware requirements.  MachineWorks can provide parts in all materials, metallic and non-metallic, in all V and synchronous configurations.   From something as simple as a verbal description up to a detailed part drawing, MachineWorks is your source for non-stock parts - from 1 to thousands of parts.

You can contact MachineWorks by email or phone:

makemymetal@gates.com  (preferred)

303-744-0385

800-709-6001

One Race To Go - John Force Racing In the Hunt for Championships

With one race remaining in the NHRA season, John Force Racing is in position to compete for the season points championship in both the Top Fuel and Funny Car classes.

Brittany Force, driver of the Monster Energy Top Fuel dragster, is in second place - only 20 points behind the class leader.  That is less than 1 round of racing.  If Force wins 1 round more than the current points leader, she will take the season championship.

Robert Hight, driver of the AAA Funny Car, goes into the final race in Pomona, CA, with a 15 point lead over the second place team.  If Hight wins the same or more rounds of racing in the final race of the season compared to the second place team, he takes home the season points championship.

Join us in watching the drama unfold in the final race of the season, following the Gates sponsored John Force Racing teams.

Underwater Belt Applications

Have an underwater drive application and don't know what belt to use?


A good option for both fresh and salt water environments would be the Gates Poly Chain® GT® Carbon™ belt.

The Polyurethane in these belts assist in its ability to withstand the submersion, and is more resistant to wear and swelling than the standard rubber belts.




If you are designing for a drive underwater, there are a few things to adhere to; Mainly:

1. Use non-corrosive/anti-rust metals (i.e. stainless steel)
2. Do not exceed 10,000 feet of water depth
3. Do not exceed 4,400 psi of water pressure

If you have any questions regarding using belts underwater, or any questions in general, you can reach us at 303-744-5800 or ptpasupport@gates.com