What Is a Roller Follower?
A roller follower is a type of compact and highly rigid bearing incorporating a needle bearing inside.
Its outer ring, in direct contact with the rolling surface, is thick-walled, hard, and features a high-precision surface. This design allows them to withstand high loads and impact loads, making them suitable for use as guide rollers in cam mechanisms and linear motion systems.
Roller followers, with their inner diameter as an inner ring, offer flexibility in shaft settings, enabling their use as compact guide rollers or cam followers with extended shafts.
These components are used in various applications, including eccentric rollers, guide rollers, rocker arm rollers, cam rollers, and pressure rollers.
Applications of Roller Followers
Roller followers are employed in scenarios where direct contact and rotation with cam mechanisms are required. Some common applications include:
Cam Mechanisms
These mechanisms, which alter motion direction, benefit from roller followers due to their ability to handle high loads and high-speed operation. Their adaptable shaft length makes them suitable for different types of cams, such as groove cams.
- Guide Rollers: Roller followers serve as efficient guide rollers, facilitating smooth and straightforward installation and operation in conveyor systems.
- Wheels: These components can be used as simple wheels for moving pallets and jig tables without needing a cart.
Principle of Roller Follower
Roller followers operate by supporting radial loads while minimizing friction. This is achieved through cylindrical rollers (needles) placed between the inner and outer rings. The rollers rotate, allowing smooth rolling of the inner and outer rings.
Internally, these bearings are typically grease-filled for lubrication. For long-term or high-speed applications, lubrication ports and holes can be added for maintenance.
Roller followers are available in two needle arrangements: full complement and with cage. The full complement type, with more needles, is ideal for high loads but not for high-speed rotation due to friction. The caged type, suitable for high-speed rotation, has fewer needles and thus a lower load capacity.
The outer ring’s rolling surface can be cylindrical for a larger contact area and higher track load capacity or spherical to compensate for any misalignment, ensuring smooth rotation.
Types of Roller Followers
Roller followers are categorized into non-separating and separating types:
Non-separating Type
This type features a steel plate press-fitted into the outer or inner ring, creating a labyrinth seal that prevents foreign matter entry and keeps side plates intact. It is designed for smooth rotation under axial and moment loads, and sealed versions have additional rubber seals for enhanced protection.
Separated Type
The separated type lacks a flange on the outer and inner rings, allowing each component to be separated and replaced individually. This design offers compactness and ease of assembly compared to the non-separated type.