4 Bolt Flange Bearings: What You Should Know

When you're involved with heavy machinery, you'll likely come across the need for a 4 Bolt Flange Bearing. If you've considering buying 4 bolt flange bearings, then you'll want to make sure you know a few things first.

4 Bolt Flange Bearings in a Nutshell

• What is a 4 bolt flange bearing?:4 bolt flange bearings are exactly what they sound like. They are bearings mounted in a square or round flange, secured with four bolts. The bearings usually move or align to accommodate the length of the shaft they support.
• What is the housing made of? The bearing housing comes in various types of materials. Each kind of material has certain properties. Cast iron is familiar to anyone who knows their way around a kitchen and frying pans. Cast iron consists mostly of natural materials; iron, with traces of silicon and carbon. The heating process determines their properties. Pressed steel is low carbon-steel, pressed rather than machined. Plastic, or thermoplastic materials, refers to organic or synthetic or processed materials that are malleable above a certain temperature and brittle upon cooling, such as nylon and teflon. Stainless steel resists chemicals and corrosives and has high pressure ratings.
• What are the bearings made of? The bearing's use and performance relate to the material used to produce it. Aluminum resists wear, carries heavy loads, and is a good conductor of heat. Aluminium is perfect for the connecting rods and bearings in internal-combustion engines. Steel is iron with carbon alloy, up to 1.7 percent. Bearings are often made of high carbon steel which is malleable under certain conditions. We distinguish steel from cast iron by the lower carbon content. As mentioned above,stainless steel resists chemicals and corrosives and has high pressure ratings. Powdered-metal bearingsare inexpensive and self-lubricating. They consist of bronze and copper alloys that are porous so they can absorb oil, graphite or PTFE. These bearings are not used for heavy loads but are helpful if lubrication is an issue. Graphite-metal alloy bearings are self-lubricating and made from melted graphite and metal. Plastic (described above) bearings have high strength and high molecular weight. They do not need lubrication and the ability to bear great weight makes them appropriate for many types of applications.
• What are they used for? We use 4 bolt flange bearings for rotary or linear movements when the bearing mounting area is perpendicular to the shaft. They come in 2, 3, and 4 bolt designs. We use the 4 bolt design for heavier loads. When selecting the bearing you need, it's important to bear in mind the size and height of the shaft. The size is the maximum diameter of the shaft or the bearing's diameter. The height above the mounting area is important if low clearance is an issue.
• Performance skills to consider: Speed is a definite consideration. That is, at how fast a speed can the bearing perform before it fails. Bearing life is the life span of the bearing at which it performs with a 90% reliability. This is known as a rating of L10. Bearing loads refers to the radial and thrust forces it must withstand. Engineering load describes the forces acting on the shaft that the bearing supports. The forces occur from the weight of the shaft, the bending and pulling of belts or pulleys and unbalanced loads. Operating temperature refers to the bearing cage, seal and grease operating at high temperatures.
• Lubrication concerns: All ball bearings require lubrication, either manual or self-lubricating. Manual lubrication requires a pump or a grease fitting to lubricate the friction parts of the bearing. Self-lubricating bearings either do not need lubrication based on the materials that comprise them, or the manufacturing process uses base metals, like bronze, that absorb oil.

To read about the differences between various types of bearings, read the article "What's the Difference Between Bearings?" on Machine Design.

To talk more about 4 bolt flange bearings, or anything else, please contact us.