Combined needle roller bearings, also known as combination bearings, are specialized bearings that combine both radial needle roller bearings and axial ball bearings or thrust roller bearings within a single unit. These bearings are designed to accommodate both radial and axial loads simultaneously. The unique combination of these two types of bearings provides high load-carrying capacity and compact design. Combined needle roller bearings are used in applications where there is a need for high load capacity and compactness. Here are the key features and characteristics of combined needle roller bearings:

1. Needle Roller Bearings: These bearings consist of radial needle roller bearings, which are cylindrical rollers that have a high length-to-diameter ratio. They are designed to handle radial loads, such as those arising from rotating shafts.
2. Axial Bearings: In addition to the radial needle roller bearings, combined needle roller bearings also include axial ball or thrust roller bearings. These components are designed to handle axial loads, which are loads applied parallel to the axis of rotation.
3. High Load Capacity: The combination of radial and axial bearing elements allows these bearings to handle high axial and radial loads, making them suitable for applications with complex loading conditions.
4. Compact Design: Combined needle roller bearings offer a compact solution for applications where space is limited, as they combine two bearing types into one unit.
5. Precision and Accuracy: These bearings are available in precision versions that provide high accuracy and tight tolerances, making them suitable for applications requiring precise positioning.

Combined needle roller bearings are used in various applications, including:

• Machine Tools: In the spindles and drive systems of milling machines, lathes, and other precision machinery.
• Automation and Robotics: In robotic arms, linear actuators, and other automated systems that require both radial and axial load support.
• Construction and Earthmoving Equipment: In heavy machinery like excavators and loaders, where loads can be complex and occur in various directions.
• Material Handling: In conveyor systems, forklifts, and other equipment that requires support for both radial and axial loads.
• Automotive Transmissions: In certain types of automotive transmissions and gearboxes, where space constraints demand a compact design.
• Textile Machinery: In spinning frames, looms, and other textile manufacturing equipment.

When selecting combined needle roller bearings, it’s important to consider factors such as the magnitude and direction of the loads, speed requirements, and the available space within the application to ensure that the bearing meets the specific demands of the equipment.