How a Roller Bearing Company Does it
A roller bearing company can make small devices that have a huge impact on the world around us and are vital pieces of the tools that make our lives convenient, mobile and safe. Although the roller bearing company makes parts that power up many of the machines we use every day, roller bearings are rarely seen by average people. In this way, they are a key to the inner-workings of the modern world.
A Roller Bearing Company Makes What?!
Yes, it’s all ball bearings, simply put, bearings are devices that reduce the friction created by motion and allow items to be moved more easily. A roller bearing is a specific type of bearing that allows an item to move by placing rolling elements (known as rollers) between two rings (known as races). The races create a kind of relative motion that allows the rollers to move with very little resistance. Roller bearings are used to move incredibly large objects without a great deal of exertion.
The concept of roller bearings and how they work can be hard to understand if you are not familiar it. Perhaps the simplest way to explain how these tools work is with one of the oldest and most well-known examples of a rolling-element bearing. In this example, a set of logs is laid out on the ground alongside each other. A very large stone or other heavy item is then laid on top of the logs and pulled along, sliding from one log to the next. As the item is pulled, the logs roll along the ground, reducing the friction that would be caused by dragging the item across the ground directly, you don’t need a modern roller bearing company for that, but you do today.
A modern roller bearing company, will use this same concept but on a more sophisticated scale. The rollers perform the same basic function as the logs, and the races are like the ground. Roller bearings use shafts in a larger hole, and the rollers tightly fill the space between the shaft and the hole. The shaft turns and the each roller performs the function of the logs by reducing the friction created by the motion. There are five main types of modern roller bearings including:
- Cylindrical roller bearings
- Spherical roller bearings
- Taper roller bearings
- Needle roller bearings
- Thrust roller bearings
Each type of bearing has its own advantages and its own downsides, depending on what the bearing will be used for. Some hold larger loads; some are more adaptable; some hold up longer. Many modern machines make use of more than one type of roller bearing to function properly. This article is designed to explain each type and what functions they can perform. This should provide some insight into the unique qualities of all roller bearings and the differences between them.
Cylindrical Roller Bearings
These are the most basic types of modern roller bearings, and they have a number of uses in modern machines. In cylindrical roller bearings, the rollers are of slightly greater length than diameter– basically the shape of a cylinder, hence the name. With these types of bearings, the rollers make linear contact along the races, and the races are inseparable. These have a high radial load capacity compared to some other types. While they have only been used on a massive scale since the Industrial Age, the earliest known cylindrical roller bearings can be dated back to 40 BC.
There are many variations of cylindrical roller bearings, but most have either one row of rollers (single-row bearings) or two rows (double-row bearings). In the case of free-end bearings, there are no ribs on either the inner or outer rings, so they can move in an axially relationship to each other. Other basic cylindrical roller bearings do have ribs on either the inner or outer rings, and these are capable of taking some level of axial load in one direction. In the case of double-row cylindrical roller bearings, they have a high radial rigidity and are commonly used in precision machine tools.
Cylindrical roller bearings also feature an element known as cages that are housed between the rollers. The cages help to reduce friction and wear by preventing the rollers from elements from rubbing against each other. In most cases, the cages are made of pressed steel or machined brass, but some cylindrical roller bearings have molded polyamide cages.
Spherical Roller Bearings
These are similar to cylindrical roller bearings, but the rollers are thicker in the middle and thinner at the ends. The rings and races of these bearings are also slightly different. In the most common design of spherical roller bearings, the inner ring has two raceways, but the outer ring only has one, and it is spherical in shape. The first spherical roller bearings were patented in 1919 by Arvid Palmgren Roller Bearing Company.
Spherical roller bearings offer the advantage of being self-aligning. Because the curvature of the raceway on the outer ring matches the bearing axis, there is less chance of both static and dynamic misalignment compared to cylindrical roller bearings. This means that excessive force will not be applied to the bearings if there is a misalignment of the axes or deflection of the housing. This means they can take axial loads in either direction as well as heavy radial loads.
Whereas spherical rollers do offer advantages over ball bearings and basic cylindrical roller bearings, they can be more expensive to produce. They also have higher amounts of friction than an ideal cylindrical or tapered roller bearing because there will be a certain amount of sliding between the rollers and the rings. Spherical roller bearings have many uses, and they are commonly found in:
- Wind turbines
- Continuous casting machines
- Fans and blowers
- Marine propulsion and offshore drilling equipment
Taper Roller Bearings
These types of bearings have cone-shaped rollers that run along cone-shaped races. The main advantage offered by these bearings is in the fact that they can support both axial and radial loads. The conical rollers are guided by a back-face rib on the cone, allowing them to handle high radial loads as well as axial loads in one direction. The first taper roller bearings were patented in 1865 by John Lincoln Scott, a farmer from Indiana.
The basic design of taper roller bearings use segments of cones as the inner and outer rings, and the rollers are tapered so that the surfaces all meet at a common point on the main axis of the bearing. This creates a linear contact which limits the sliding motion between the raceways and the surface of the rollers. The rollers are mounted in pairs, and the proper internal clearance is obtained by adjusting the axial distance between the cones of the two opposed bearings. Tapered roller bearings are divided into three categories depending on the contact angle:
- Normal angle
- Medium angle
- Steep angle
Tapered roller bearings are commonly used in vehicle wheel bearings, where they are forced to cope with both large radial and axial forces. Other uses include gearboxes, engine motors, propeller shafts, railroad axle box and others.
Needle Roller Bearings
These types of bearings are similar to cylindrical roller bearings but with much thinner rollers. Needle roller bearings are made up of several slender rollers that have a length that is anywhere from three to 10 times their diameter. Because the rollers are so thin, the outside diameter of the bearing is only slightly larger than the hole in the middle, allowing for a much higher radial load capacity.
Usually, the ends of the rollers taper to points, or they are hemispherical and held by the shaft itself. This means that many needle roller bearings have no inner rings at all. Most have pressed steel cages, but others do not have cages either. Needle roller bearings are some of the most common bearings in many automobile parts. They are heavily used in:
- Rocker arm pivots
Thrust Roller Bearings
Thrust roller bearings have many uses, and they provide the distinct advantage of being able to handle very large axial loads. They can also handle moderate radial loads when an axial load is also applied. The first thrust roller bearings were patented by a roller bearing company in Australia in 1905 by engineer George Michell.
These bearings use consist of cylindrical rollers arranged flat within a spherical housing washer. The rollers have their axes pointing towards the axis of the bearing, and this allows for a high axial capacity. Because the raceway inside the housing washer is spherical in shape, thrust roller bearings are self-aligning. The cages are usually made of pressed steel or brass.
Thrust bearings have many uses and are commonly used in automotive marine and aerospace applications. They are very common in modern gearboxes which use helical gears.
A Roller Bearing Company Makes The World Go ‘Round.
While there are many variations of roller bearings, they are all based on the idea of reducing friction and allowing objects to move more easily. Based on this simple concept, roller bearings can be used to help power some of the world’s most complex machines. Whether it is a car transmission, a radio antenna, a wind turbine or a space shuttle, machines would not function properly without the use of roller bearings.