No matter what you do daily, you probably come into contact with one, if not many different devices that utilize bearings.
Bearings are used in all kinds of applications from airplanes and the car you drive to your desk chair and the Lazy Susan in your spice cabinet.
Their goal is to ensure motion is regulated in a moving part and help reduce friction.
Since bearings are so crucial, many different bearing types have been developed for various loads and jobs, so it's key to make sure you know how to differentiate between them all so they fit your customer's needs.
We know it's stressful going outside of your typical supply chain to find the correct bearing for your customer and ordering globally can be a daunting task.
At Bearing & Drive Systems, we're committed to providing global sourcing network solutions that help you find the authentic bearing & PT products that your customers need now.
If you're looking to learn about the history of how bearings were invented, how to identify a bearing, the different types of bearings, and their applications, then you'll find this guide extremely useful.
Let's dive in!
The History Behind Bearings
Picturing a world without bearings would be quite challenging since every machine that uses some kind of motion uses bearings to smooth out that path and reduce friction.
Bearings are an incredibly important piece of technology whose invention stems back centuries.
Before we had the varying types of bearings like roller bearings, steel ball bearings, or thrust bearings, there were merely bearings made out of wood. These "old wooden rollers" supported objects the same way that present-day precision bearings do.
According to IQS Directory, "some historians would say that the invention of bearings may even predate the invention of the wheel."
Bearings most notably impacted the 1st Industrial Revolution thanks to their role of allowing machinery to operate more efficiently.
The first plain and rolling element bearings produced out of wood and bronze, but as they evolved, more and more saw bearings made of various materials like ceramic, steel, sapphire, glass, and more.
Watchmakers used plain sapphire bearings when building watches because they were known to prevent friction, which meant more precise timekeeping.
Nowadays, wooden bearings can be found in places like old water mills and clocks, but they are much more uncommon.
Check out this 2-minute video to get a quick look at the history of bearings...
Source: Emerson Bearing History of Bearings, via YouTube
Timeline of Bearing History
2600 BC - Ancient Egyptians used a form of roller bearings to assist in moving large stone pieces that were for the construction of the Pyramids.
40 BC - An early known example of a wooden ball bearing was used to support a rotating table. This example was found in the remains of a sunken Roman ship in Lake Nemi, Italy. [source]
1500 AD - Blueprint drawings and the early concept design of a helicopter by Leonardo da Vinci used ball bearings. This is the first known recorded use of bearings in an aerospace design.
17th Century - Galileo describes the caged bearing for the first time
1740 - John Harrison invents the first caged-roller bearing for H3 marine timekeeping. Little did he know, he used the same bearing in a contemporary regulatory clock.
1794 - The first patent for ball race was awarded to Philip Vaughn of Camarthen, Wales. His design incorporated a ball running along a groove in an axle assembly.
1869 - Parisian bicycle mechanic Jules Suriray receives the first patent for a radial ball bearing, which he fitted on the winning bike of the world's first bicycle race in Paris.
1898 - First patent is issued for Timken Tapered roller bearings. In the next year, Henry Timken established his company.
1907 - Sven Wingquist of SKF invents new self-aligning ball bearings. This set a new standard of design, and from it, innovations popped up like the wire race bearing in 1934 and the v groove bearing in 1968, respectively.
1917 - During World War I, U.S. bearing manufacturers decide to create an informal group to assist in bearing manufacturing. This leads to the founding of The American Bearing Manufacturers Association (ABMA).
1980s - Here, we saw the first bi-material plain bearing, which was invented by Robert Schroeder. Schroeder was the founder of Pacific Bearing.
2000s - Now, we see ball and roller bearings used in all kinds of industrial applications from wheel bearings in the automotive industry to ultra-high-speed bearings used in dental drills, and anything in between.
If bearings had never been invented, it's safe to say that humankind would have been negatively impacted.
We would still be trying to figure out how to exert large amounts of force to move heavy objects. Yet, we wouldn't have the conveniences of modern machinery that are credited to the invention and constant innovation of bearings.
If history repeats itself (as it often does), we could see more advanced and impactful changes that will affect and adjust the bearing industry.
Now that we've covered the detailed history of how bearings came about and how they made a permanent impact on industrial applications let's break down the different parts that make up a bearing.
What are the Different Parts of a Bearing?
In its current form, the modern-day bearing you probably are picturing was developed towards the end of the 19th century, and before that time, it was crafted by hand.
Present-day, bearings are one of the most common machine parts thanks to their rolling motion, which reduces friction and makes movement easier.
Bearings serve two essential functions -- they transmit forces and transfer motion. Their components, on the other hand, usually consist of the following:
- Two rings or discs with a raceway
- Rolling elements (either in the form of rollers or balls)
- A cage (which serves the purpose of keeping roller elements apart and guiding them properly)
Let's discuss further...
Outer Race and Inner Race
These parts of the bearing provide the housing for where the balls of the bearing rest. Typically, a groove is cut into the race's inner circumference, so the balls move freely but can stay in place and not fall out. The inner race is positioned inside the outer race.
Both the outer and inner race's goals are to hold the balls in place in between. The inner and outer races are prone to cracking if they're exposed to extreme forces, so it's crucial to keep in mind that you design them using extremely durable material.
Often high-purity, chrome alloy steel is used for both races as it has the needed hardness and purity that is highly sought after for a high load rating and long service life.
Other special materials that are used include ceramic and plastics, which depend on the application. Plastics cannot withstand high temperatures like steel, but they are much lighter, making them used in the automotive industry.
These consist of balls, rollers, cones, spheres, or needles. As we discussed earlier, these are fixed between the inner and outer races, which allow them to rotate freely. These components are critical because, without them, friction between the races would quickly damage and ruin the bearing.
The cage is responsible for keeping the rolling elements apart and guiding them. Materials that are commonly used for this component include steel, plastic, and brass.
According to NSK Europe, solid metal cages are produced through machining techniques and pressed cages are made from sheet metal.
These components are essential for extending the life of a bearing.
Bearing shields' primary purpose is to seal the bearing to prevent harmful contaminants like dust from getting inside where the critical components reside and keep the bearing's lubricant in place longer. If dust or other contaminants were to get inside, or lubricant was to leak out, it would quickly damage the other components due to friction and corrosion.
Although bearings seem simple due to their design's nature, their performance is critical for the operation of an entire machine or device. If one component breaks down, it can cause unexpected downtime in your facility due to a bearing failure.
Bearing Classification Explained
Since technology in the industrial market is continually improving, we often overlook bearing maintenance and installation best practices that keep bearings performing their best day-to-day.
It's no secret that identifying bearings is an essential skill that anyone can learn in the industry with a little practice.
Because of this, we thought it was crucial to discuss how bearings are classified.
Diving in, there are a few steps you need to walk through to identify a bearing correctly.
First, depending upon the force's direction, you need to determine if the bearings are classified as either Plain (Sleeve) Bearing or a Rolling Bearing.
Plain (Sleeve) Bearing
These are the oldest styles of bearings and found in numerous applications in your home, car, or machinery that operate at low speeds and lighter loads.
According to IBTINC, while they vary in shape and size, these bearings function as "a band of close-fitting material that encloses and supports a moving member, or forms a “sleeve” around the shaft."
Plain bearings can be either mounted and unmounted.
These bearings can also be mounted or unmounted and utilize both ball and roller bearings.
This bearing style is composed of one or two rows of balls or rollers (made from steel) that reside between inner and outer rings.
Often raceways or grooves are cut into the rings to guide the rolling elements properly.
Once you figure out if your bearing is a plain or rolling bearing, you can move on to step number two of identification.
Depending on the load type of bearing, they can typically be classified as either:
- Bearing with a steady load (these types of bearings are called "power bearings")
- Bearing with a variable load
Now you can move on to the final step in classification...
There are four primary classifications of bearings to keep in mind when you identify bearings commonly used day-to-day:
- Radial ball
- Cylindrical roller
- Tapered roller
- Needle bearings
In addition to the above, there are many different types of bearings used for more specific applications.
Now that we've identified these bearings, we can dive deeper by discussing the different types in detail and standard applications in the next chapter.
Bearings: How to Choose Between Ball, Cylindrical, Tapered or Needle
While there are several types of bearings on the market, the primary types are ball bearings, cylindrical roller bearings, tapered roller bearings, and needle bearings.
Ball bearings are the most commonly used; however, each type has its own unique set of advantages and disadvantages to keep in mind.
That said, it's recommended that you compare each type of bearing to narrow down which one is ideal for your or your customer's needs.
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the moving parts.
Compared to other similar bearings, this kind is the least expensive, and it's used in all types of applications where the load is relatively small, from skateboards to power drills.
Advantages: Low-cost, compact, most widely used
Disadvantages: Only supports moderate axial loads
Cylindrical Ball Bearing
There are several different types of cylindrical roller bearings on the market.
They vary according to the number of rows of rollers (usually one, two, or four) and if there's a cage or not. No cage allows for the bearing to have more rows, which helps support even heavier radial loads. [source]
These types of bearings are commonly used in rotary applications.
Cylindrical roller bearings can support significant radial loads (even very significant ones).
Advantages: long bearing life, support significant radial loads, robust
Disadvantages: Cannot tolerate high speeds if the bearing doesn't have a cage
Tapered Roller Bearings
"Tapered roller bearings are known for their ability to support radial, axial, and combined loads (both simultaneously)," according to Direct Industry. Due to their rigidity, the loads can be hefty.
If you're not sure if you should use a ball bearing or a tapered roller bearing, keep in mind that a tapered roller bearing with the same dimensions can support heavier loads. [source]
This bearing is recommended for applications like vehicle transmissions, steering of car or truck wheels, machine spindles, and more.
Advantages: They can be adapted to support high radial or axial loads (or both).
Disadvantages: Do not support high rotational speeds
Like cylindrical roller bearings, needle bearings can come with or without a cage; if they have a cage, they can tolerate very high speed, but if they don't have a cage, they can support significant radial or axial load.
Needle bearings are widely used industrial bearings and are typically used in applications such as gear pumps, aircraft construction equipment, gasoline engines, and other engine components.
Advantages: Supports strong radial loads, the overall dimension is reduced
Disadvantages: Sensitive to misalignment
Check out this detailed video by Learning Engineering that further explains the different types of bearings on the market.
Source: Types of Bearings - Different Types of Bearings by Learning Engineering, via YouTube
It's nearly impossible to imagine a world without bearings and the technology they make up.
As we've discussed in this post, bearings have become an essential part of day-to-day life since their invention thousands of years ago.
Finding authentic bearing and PT parts that you need shouldn't be a hassle.
At Bearing and Drive Systems, we know that the worry of providing inferior products to your customers is real, but it doesn't have to be.
Our global sourcing network solutions can help you find the authentic bearing and PT products you're looking to help you reduce downtime and guarantee the quality you and your customers deserve.
Talk to one of our bearing experts today to tell us what you need, and we can help you get started.