Linear Motion Bearings
Often used in industries such as automotive, aerospace, farm, and construction equipment, needle bearings have a high load carrying capacity and a very small section height. Using these bearings help machine designers keep dimensions down in applications where space and weight should be limited. The aerospace industry is great example of this, where needle bearings are used for wing flap and slat track rollers, in hinges and in landing gear. Unfortunately, the qualities that make them ideal for these uses also imply intrinsic disadvantages. Though they have high load carrying capacity, they cannot withstand axial loads and will fail if any vector force is applied parallel to the shaft.
Standard needle bearings are viewed as weaker than other bearings simply due to their size, but a heavy duty cam follower is a needle bearing designed for outer ring rotation. These followers have high resistance to shock loads and can endure heavy radial loads. They can also withstand bi-directional axial loads. Cam followers with an integral stud are used for cantilever mounting and followers with an integral inner race are used for yoke mounting. Each of these may come with a crowned outer diameter and this crowning often counterbalances for bearing misalignment and distributes stress over the track.
It is important to think about speed, alignment, load, cam design, and lubrication when deciding on a cam follower. Shock loads may require a yoke roller or heavy stud cam follower. A bearing size chosen from the given load and speed for a specific life requirement is recommended when operating speed is less than maximum allowable speed. Lubrication is also very important when it comes to cam followers. Devices that apply automatic and intermittent lubrication are recommended.