Vehicle bearings types

Rolling bearings are indispensable components in various mechanical systems, enabling smooth and efficient movement and reducing friction. There are many types of rolling bearings, each designed for specific applications. In this blog post, we will outline some of the most common rolling bearings, including ball bearings and roller bearings, introducing their types and their capabilities in terms of force, speed, and load.

A rolling bearing is a mechanical device consisting of an inner ring, an outer ring, rolling elements (balls or rollers), and a cage. They are used to withstand radial and/or axial loads, enable rotational or linear motion, and reduce friction between moving parts.

Axial Load vs. Radial Load

A key point of comparison between different types of bearings is their load-carrying capacity. A load refers to the force applied to a bearing. These loads can be radial or axial. A radial load is a load applied perpendicular to the shaft, while an axial load is a load applied in the same direction along the shaft. A combined load is a load that applies both radial and axial forces to the bearing simultaneously. Different bearings have different load-carrying capacities.

Ball Bearings vs. Roller Bearings

Ball bearings and roller bearings are two distinct types of rolling bearings, with significant differences in their design and function. Ball bearings drive motion by rolling steel balls between inner and outer raceways. They have low friction and excellent high-speed performance. While ball bearings excel in high-speed applications, roller bearings are better suited for heavy-duty conditions. Roller bearings use cylindrical or tapered rollers to carry loads. Due to the larger contact area of the rolling elements, roller bearings offer higher rigidity, stability, and load-carrying capacity than ball bearings.

Ball bearings

Deep groove ball bearings: Deep groove ball bearings are the most common type of ball bearing. They have deep raceway grooves and can withstand radial and axial loads. Their low torque characteristics make them ideal for high-speed applications. Deep groove ball bearings are easy to maintain and less sensitive to operating conditions, making them suitable for a wide range of applications.

Self-aligning ball bearings: Self-aligning ball bearings consist of two rows of balls that move under the guidance of a cage and have a double-row inner ring raceway. Due to their unique structure, these bearings can accommodate misalignment between the shaft and the bearing housing, making them suitable for applications where shaft deflection or misalignment may occur. They have good radial load capacity and are commonly used in medium-speed applications.

Angular contact ball bearings: Due to their unique structure, angular contact ball bearings can withstand combined loads. There is relative displacement between the inner and outer raceways along the bearing axis. As the contact angle (the angle between the line connecting the ball and raceway contact point in the radial plane and a straight line perpendicular to the bearing axis) increases, the axial load capacity also increases. This design allows them to withstand high axial loads while also possessing good radial load capacity.

Thrust ball bearings: Thrust ball bearings are designed to withstand axial loads only and should not withstand radial loads. They are available in unidirectional and double-direction designs. A unidirectional design consists of two grooved washers (shaft washer and housing washer) with the rolling elements (balls) located between them. A double-direction design consists of three washers and two ball cage assemblies, separated by the shaft washer. Thrust ball bearings are easy to disassemble and interchange, making them ideal for low-speed applications.

Roller bearings

Tapered roller bearings: Tapered roller bearings can withstand unidirectional combined loads. Their tapered and cup-shaped raceways efficiently transmit radial and axial forces. Tapered roller bearings can be arranged in two-row or four-row configurations, enabling them to withstand bidirectional combined loads. Tapered roller bearings are best suited for medium-speed combined load applications.

Spherical roller bearings: Spherical roller bearings are designed to withstand large radial loads and moderate axial loads. Their design is similar to that of self-aligning ball bearings, but they use spherical rollers as rolling elements. This allows them to compensate for misalignment. Spherical roller bearings have a barrel-shaped outer ring and two rows of rollers, and can be open or sealed. Spherical roller bearings perform excellently in applications involving high speeds, heavy loads, and impact loads.

Cylindrical roller bearings: Cylindrical roller bearings have extremely high radial load capacity and moderate axial load capacity, with the specific load capacity depending on their structure. They consist of cylindrical rollers and are suitable for applications that withstand high radial forces and high speeds, while also being able to withstand impact loads.

Needle roller bearings: Needle roller bearings use slender cylindrical rollers, resulting in a compact structure and high load-carrying capacity. They are particularly suitable for applications with limited radial space and high radial load requirements, but not for axial loads. The length of the needle roller is several times its diameter, and in some designs, it can even be up to 10 times the diameter. Needle roller bearings are best suited for applications with limited space and high radial loads.

The above is a basic introduction to some of the most commonly used bearings. Understanding the different types of bearings and their capabilities in terms of force, speed, and load helps in selecting the most suitable bearing for a specific application. By considering these factors, engineers and designers can ensure that their machinery and systems achieve optimal performance, durability, and efficiency.