Bearing Design Guide: Chapter One: DESIGNING THE SLEEVE BEARING

Just another day at the office…

Ring, ring….

Super Awesome Atlas Employee: Good Morning Atlas Bronze, how may I help you?

Customer:  Well…I need a bearing and I’m not sure what kind.  This is for a new project and we       are starting from scratch so I could really use some help.

HELP…did you hear that?…HELP!  Dun da na na (trumpet sound)…We have a guide for that!

Bearing Design Guide: Chapter One:  DESIGNING THE SLEEVE BEARING

First, to get started there are key things needed to know and all of these will influence the final design, material or alloy of choice.  They are as follows:

•          Load

•        Speed

•       Shaft Material

•       Finishes

•       Hardness

•       Clearances

•       Lubrication

All of these factors must be considered to determine which is the most important so that the bearing can be designed to meet the highest need for the application.

The more obvious factors which are speed or type of motion, for example, rotating, oscillating or reciprocating combined with the type of load as intermittent, continuous, with or without shock or impact loading, usually point to the mode of lubrication that may be indicated.

That is, the “Pressure Velocity” factor (PV) gives a good clue of the possible success based on its product.

In order to get the PV, you need to convert the total weight (W) to be supported in pounds to the unit load (P) in pounds per square inch (PSI) and the speed in revolutions per minute to the velocity (V) in feet per minute. 

Below you will fine the formulas used for Rotary Motion, Linear Motion & Oscillating Motion.

Rotary Motion

   Pressure (P) = Total Load (W) I Projected Bearing Bronze Area = PSI

              Note: P is the unit load in PSI

  W is the total load in  pounds

  PBA is the bearing diameter times the length

 

   Velocity (V) = π x D x N/12=.262 DxN=fpm

            Note: V is surface feet per minute

                       π is a constant 3.1416

                        D is the shaft or bearing dia.

                        N is the RPM

                    

Liner Motion

   Pressure (P) = Total Load (W) I Projected Bearing Bronze Area = PSI

              Note: P is the unit load in PSI

  W is the total load in pounds

  PBA is the bearing diameter times the length

   Velocity (V) = feet traveled per minute  (length of stroke)

                      

Oscillating Motion

   Pressure (P) = Total Load (W) I Projected Bearing Bronze Area = PSI

              Note: P is the unit load in PSI

  W is the total load in pounds

  PBA is the bearing diameter times the length

               

   Velocity (V) = .0029 x ID x Degree in one stroke

For applications having ideal lubrication, the PV factor 

can range well above 150,000.

For severe service, the PV factor should be reduced to 90,000 . 

For extreme severe duty, the PV factor should be reduced to 60,000 .

Using an arbitrary limiting bearing temperature of 250 degrees F, and using the power formula. MDWN, with an assumed constant friction factor (M) of .075, a relatively straight line value can be obtained. This result  should only be used as a guide because other factors and considerations may modify and affect the final decision.

The heat so generated  by a load (P) in combination with a low velocity (V) will be substantially less than with a low load. (P) and a high velocity (V) because velocity or speed influences the temperature  more than load or pressure does.

In actual bearing service, and as a general rule, bearing temperatures should not exceed 140 degrees F to 160 degrees F or endure a rise of more than 70 degrees F.  For large or heavy equipment applications, a temperature rise of 55 degrees F is acceptable.

Well...that's it for today.  I hope your head isn't spinning as much as mine was the first time I read this!  Until next time my metal loving friends... 

Next Up:  Week Two, Chapter 2: Lubricating Modes

You want me to make what?! Using and Understanding the Bearing Design Guide

 You want me to make what?!  I'm sure we've all said that a time or two in this industry.  When a customer comes to us with a request for quote, we want to make sure we have all the knowledge we need to provide them with a perfect part.  Sometimes we get stumped by which is the right material to use or what kind of bearing would be best for their specific application.  Well, have no fear...we have a guide for that!  In the next coming months on the Metal Chic, we will be featuring the "Bearing Design Guide".

 
This guide was created to help understand in a simpler way the process of designing and manufacturing a bearing from start to finish. It was written by Mr. S.J. Hudak who has had over 50 years of experience and knowledge in the industry during his employment with various bronze companies.

It has been applied successfully to sleeve bearing problems and designs by Mr. Hudak based on his interpretation of various engineering papers and bearing articles along with personal experiences and observations of tests.

When I started in sales almost nine years ago, it was a requirement to read this guide and I have to say it has been helpful over the years.  Here at Atlas Bronze we love to help people and are always looking for ways to do just that. So...starting August 1st, we will be taking a look at this guide chapter by chapter.  Each week we will explore a chapter in a summarized way, but focusing on all the key pieces of information needed to design the best bearing for your customer.

I hope you will join me on this journey so we can do what we do best and help you learn something new.  If you would like your own copy of the Bearing Design Guide Click Here and you will be taken to our websites homepage where you will be able to order a free copy.


Next Up:  Week One, Chapter 1: Designing The Sleeve Bearing

How Atlas Bronze Could Help if Santa's Sleigh Broke Down on Christmas Eve

Every Christmas Eve, countless children lie restlessly in bed, thinking about all the toys that they hope to find under the tree on Christmas morning. They’re barely able to contain themselves as they anxiously await Santa’s arrival, depending of course on how well-behaved they were the past year.

I remember when my kids used to look wistfully into the dark, winter sky from their bedroom windows, waiting to catch a glimpse of Santa’s sleigh flying through the air. They would point and jump up and down when they saw Rudolph’s red nose, and my husband and I would agreeably nod, even though we knew it was simply a blinking airplane light. So few things are as boundless as a child’s imagination!

One day, a terrible thought crossed my mind. If Santa was in fact real, how devastating would it be if his sleigh broke down during his annual expedition to deliver gifts to the girls and boys of the world? The kids would wake up and fervently rush down the steps only to find the harrowing sight of a Christmas tree devoid of any gifts beneath it.

Well, if Santa’s sleigh did break down, I know just the people who could (probably) fix it. Atlas Bronze of course!

If Santa’s sleigh was a real vehicle making these millions of trips all around the world in one night, an obvious source of potential troubleshooting would be with the engine. First, Atlas Bronze would go straight to the source and inspect the engine’s valve seats, or the strength center part of the engine that prevents harmful gases from leaking into the manifold. Aluminum bronze is a key component of the valve seat and also helps prevent corrosion. With the addition of bronze parts for added strength, Santa’s sleigh would be dashing through the snow again in no time!

Since Santa has been so busy making a list and checking it twice, we’re sure he hasn’t thought about the exterior of his sleigh and how it could endanger him on his merry travels. Before Saint Nick goes on his merry way, he would need to incorporate some architectural bronze into the exterior. Bronze is commonly used in the production of doors, making them nice and strong. As an added bonus, bronze will not generate sparks when struck against a hard surface. So, as Santa lands up on the housetop with a click, click, click, he can ensure that his trusty sleigh won’t slide off of the roof.

Finally, you can’t forget about the bronze sleigh bells on the reindeers’ harnesses. As Santa’s original bells may have rusted over many years, he might go to Atlas Bronze to get the materials he needs for a shiny new outfit for Rudolph.

Deck the Halls with Bronze

It’s that time of year again! As the garland is wound up the staircase, the tree is propped up and adorned with ornaments, and strands of light are wrapped around the window frames, you just can’t help but get into the holiday spirit. Even if only half the lights actually light up (resulting in hours of frustration), decorating is one of the most fun parts of the season, especially when done with your loved ones.

The common theme for Christmas decorations involves lots of greens, reds, golds and silvers. We also see a lot of ceramic, cloth and glass in various holiday-themed displays. However, bronze has really made a comeback in recent years as a fresh alternative to those classic colors.

This is because bronze decor can make your home even more glamorous, as the metallic hues add a striking effect to any room.

Although I’m not an interior decorator, I’ve been reading that the professionals are seeing a lot more copper and bronze and jewel tones brought into holiday decor. Furthermore, by integrating bronze into your holiday decor and color scheme, you can create a lavish feel without overwhelming your space.

I found some great examples of bronze decor in my research, and have included them below:

• If you’re looking for a vintage, mid-century, modern feel, you can find antique bronze candle holders. Even better: if you have old candle holders in your attic, you can definitely polish them and make them look brand new! 
• To make your tree shine even brighter than before, add ornaments finished or accented with rich bronze. 
• Angel or star tree toppers with intricate designs and trendy bronze finishes can add the perfect finishing touch to your Christmas tree. 
• If you’re having company over for a nice dinner, you can set your table with bronze charger plates. Charger plates are large, decorative plates used to dress up dinner tables at parties and other special events. 
• Bells, especially church bells, have traditionally been associated with Christmas for a long time. Hanging bronze bells from the tree or in the doorway will create a traditional look for your home. 
• And, as you wrap presents for your family and friends, try a dark bronze, shimmering wrapping paper to add a classy, modern style to your gift-giving. 

Bringing these metallic elements from the tree to the mantel to the front yard or door, you can create a cohesive, simple decorating scheme with a modern edge. And you probably won’t want to take the decorations down!

Giving Thanks for Bronze

It’s a typical tradition for families to sit around the Thanksgiving table and announce what each individual is thankful for. I can easily think of many things that I’m so thankful for, such as my family and friends, and my wonderful job. Although these responses are typical for many people, if you considered all of the essential things made of bronze that we use so frequently in our lives, bronze might come up at the Thanksgiving dinner table more often.

Just as an example, we can pick out the many bronze items that help us celebrate Thanksgiving and kick off the holiday season.

Upon waking up on Thanksgiving morning, we are greeted with the sounds of bronze coming from the annual parade on TV. Cymbals and guitar and piano strings all come from this ubiquitous metal.

Additionally, bronze is an ideal material for electrical connectors, which are used to join electrical circuits. Electrical connectors power electronics including lamps, computers and the televisions that we use to watch the parade and, of course, Thanksgiving Day football.

Then, as we drive to our relatives’ houses in anticipation of great food and company, we may want to give thanks for bronze bearings. Bearings are components that allow heavy machinery to move heavy loads very quickly with little friction. Bearings are key elements in the steering wheel, engine and transmission of our cars.

Bearings are also essential for the function of electric ovens, which many people use to make their perfectly bronzed turkey - no pun intended. On a side note, interestingly enough, the most popular Turkey variety for most of American history is actually named the Bronze Turkey... How about that for coincidence?

Finally, many hammers, mallets, wrenches and screws are made of bronze. These tools are used for general purposes, including constructing the tables that we sit at during Thanksgiving dinner.

So, as you gather around and raise your glasses to toast, you can really surprise your family members with something they surely won’t expect you to be thankful for.