Bearings are movement constraining and assisting elements which work radially. They are produced in various types and sizes depending on the requirements. The major two categories of these are; ball bearings and roller bearings. The rollers or balls inside the bearings, precisely aligned with each other, are positioned between two rings (an inner and an outer ring) in order to minimize the friction. Thus, they can handle various loads. Bearings minimize energy leaks as they move by rolling rather than sliding. They have a large area of use.
Ball bearings have the highest rpm limit of all bearing types. In this type, only the tip of the balls contact the rings due to their spherical structure. Therefore, higher rpms may be achieved with less friction as they provide less contact surface compared to the roller bearings. Depending on the radial clearance and the axis position under normal operating conditions, they can be installed at an angle of 8-16 degrees. Generally single row ball bearings with non-contact seals as well as bearings with contact seals are available in the standard mass production programs. Bearings with covers on both sides are maintenance-free and suitable for operating in environmental conditions between 20-120°C (253K-293K). The radial load carrying capacity of the double row ball bearings is higher than the single row ones, but their longitudinal load carrying capacity is lower. These bearings are not suitable for tilted positions.
Cylindrical roller bearings are radial bearings that can be disassembled. The linear contact between the rollers and the rolling path is optimized hence the stresses and the strains are decreased. Radial load carrying capacity allows for a tilt in every 2-4 minutes. These bearings are much more durable than ball bearings. It’s difficult to break them.
- The components of the bearings are:
- Outer Ring
- Inner Ring
- Cage (Steel, Brass, Polyamide)
- Rolling Elements
Bearings are positioned in two rings, rotating in opposite directions. Accordingly, minimum friction is achieved with rollers. Thus, they carry different loads with respect to their dimensions/sizes. They absorb the effects caused by friction as well. As a result, they consume less energy.
Area of Use of Bearings
Bearings are used in almost every type of machinery in various sizes. Today, there are more than 300,000 types of bearings. The function of each machine changes proportionally to its size. These bearings, which have a wide range of application, can support radial or axial loads. These are classified as radial and thrust bearings. Bearings are being used in all areas in our lives such as planes, trains, subways, buses, dentist equipments, trucks, domestic appliances, microscopes, wind turbines and all machinery which require a movement transmission. The most important detail that affects the work life of the bearings is their quality. High quality bearings work at higher rpms and with less noise. Besides that, they are manufactured more durable with the use of better materials.