Radial Ball Bearings: What You Need to Know
Do you know the primary advantages of radial ball bearings?
A standard model in the ball bearing industry is the radial ball bearing. It is comprised of the outer race, the inner race, the balls, and the cage (also known as a retainer). The retainer keeps the balls evenly spaced, so the bearing load is evenly distributed.
The measurements of a radial ball bearing can be broken down into three important dimensions: the inside (or bore) diameter, the outside diameter, and the face width. These dimensions are critical because they determine whether the bearing will fit correctly on the shaft or inside the mounting enclosure, if necessary.
Most ball bearings have the balls in a single row around the race. The single row radial ball bearing is the simplest and most common anti-friction bearing. In this design, the load on each ball is carried at two points. This is known as point contact. This means that the entire load of the ball is concentrated at these two points. This feature prohibits them from carrying extreme radial loads, but allows for higher speeds.
Other advantages of the radial ball bearing include its versatile design configurations. These configurations can tolerate a wide range of loads and speeds. The point contact feature gives the bearing very low rotational friction. These bearings are a great fit for situations requiring high speeds. Another big advantage of the radial design is its low cost.
The disadvantages with the radial ball bearing include low radial load capacity and low axial load capacity. Another disadvantage of radial bearings is that they require a tight shaft tolerance to ensure proper operation. Because of this, bearing-quality shaft material and housing seats must be used.
Several design types of radial ball bearings exist on the market, and each has its own advantages, disadvantages, and uses.
The Conrad design method is very common and does not require a loading slot for ball placement. Instead, these bearings are assembled by placing the inner ring into an eccentric position relative to the outer ring, with the two rings in contact at one point, resulting in a large gap opposite the point of contact. The balls are inserted through the gap and then evenly distributed around the bearing assembly, causing the rings to become concentric.
Maximum capacity bearings can carry higher loads than the Conrad design. This is because loading slots allow for the addition of extra balls. As with any ball bearing, more balls means more surface area for the distribution of radial load.
One popular radial bearing for the combination of radial and axial loads is the angular contact ball bearing. The ball contact angle and the shoulder that is machined in the outer ring, provide higher axial load capacity in one direction.
Super precision ball bearings are available in both radial and thrust designs. They are used for situations that call for higher speeds, more accuracy and when greater stability is needed. They are specifically made to handle rigid, high speed, high precision machine tool spindles.