RealiSlim Open Bearings

Reali-Slim® thin section bearings are precision components widely used in various applications. It's worth noting that Reali-Slim® bearings are expensive, with prices ranging from thousands to tens of thousands of dollars, making them less friendly for small to medium-sized companies and individual enthusiasts. Fortunately, Aubearing is a manufacturer and leader in thin section bearings in China. Aubearing's Reali-Slim® thin section bearings are equivalent to the Kaydon series and are priced at only one-twentieth of the cost of Kaydon bearings of the same model, significantly reducing design costs and providing economic benefits. If you are unsure which Reali-Slim® bearing model to choose, contact Aubearing engineers immediately. They will respond promptly and make the right decision for you.

Design of Reali-Slim® Thin Section Bearings

Components of Reali-Slim® thin section bearings include inner and outer rings, rolling elements, and cages. The inner and outer rings are the main parts of thin section bearings, with rolling elements rolling between them. The role of the cage is to maintain the stable position of the rolling elements and keep them separated to prevent contact. Inner and outer rings are typically made of high-strength stainless steel, high-carbon steel, or ceramics. Rolling elements are usually made of spherical or cylindrical high-hardness materials such as ceramics or hard alloys. Cages are typically made of chrome steel, aluminum alloys, polymers, etc.

Reali-Slim® Bearings from Aubearing

Aubearing's Reali-Slim inch series thin section bearings include seven open series and five sealed series, with bore sizes ranging from 1.000 inches to 40.000 inches. Their cross-sectional areas range from 0.187 x 0.187 inches to 1.000 x 1.000 inches. Aubearing also offers internal components, lubricants, separators, and other features to meet the most demanding application specifications. (For better corrosion resistance, Kaydon stainless steel Reali-Slim or Endura-Slim series bearings are a good choice. Endurakote coated bearings provide corrosion protection equal to or better than AISI 440C stainless steel bearings). Other variants of Reali-Slim thin section bearings include Reali-Slim MM metric series bearings, ultra-thin section bearings, Reali-Slim TT series turntable support bearings, and BB metric ball bearings. In these series, you can choose open thin section bearings (for applications where the bearing is not exposed to harmful particles) and sealed bearings (for applications where bearings need to be kept clean and well lubricated).

Type of Reali-Slim® Thin Section Bearings

To support various loads in applications, Aubearing Reali-Slim bearings come in three basic types: radial contact (C type), angular contact (A type), and four-point contact (X type). Designers can also choose from a wider range of types to meet load, stiffness, and precision requirements most effectively, such as KA, KB, KC, etc.

C Type Radial Contact Bearings

C type radial contact bearings are Conrad-type components, a single-row radial ball bearing design. It is assembled by offsetting the inner ring within the outer ring, allowing for approximately 50% ball insertion. C-type bearings primarily carry radial loads but also allow for thrust loads in either direction - typically used in conjunction with another bearing. However, if carrying thrust loads, angular contact bearings should be considered.

A Type Angular Contact Bearings

A type angular contact bearings have smaller shoulders on the raceway side of the inner or outer ring. Cartridge-type components allow for integrated circular pocket separators and larger balls. A-type angular contact bearings can withstand radial loads and unidirectional thrust loads, typically used in conjunction with a similar structure of another bearing. A-type bearings have a 30° contact angle and approximately 67% full ball complement. The main advantage of A-type bearings is their ability to withstand larger thrust loads compared to C-type or X-type bearings.

X Type Bearings (Four-Point Contact)

Reali-Slim Type X four-point contact bearings have a gothic arch geometry on the inner and outer rings, allowing a single bearing to withstand three types of loads (radial, axial, and moment). This makes it the preferred choice for many applications, as a single four-point contact bearing can often replace two bearings, greatly simplifying the design. For applications requiring greater stiffness or zero free play, X-type bearings can also be equipped with internal bore preload. This is achieved by using balls that are larger than the space between the raceways. Thus, some elastic deformation will occur in the balls and raceways in the absence of external loads. Note: Aubearing does not recommend using two X-type bearings on a shaft simultaneously, as this may cause additional friction torque.

Installation of Reali-Slim® Thin Section Bearings

The cross-section of Reali-Slim bearings is very thin, making them very sensitive to the fit between the shaft and the bearing seat. Proper installation is crucial to ensure that thin-section bearings perform as expected. Many factors need to be considered during installation, including: bearing type and orientation, direction and magnitude of applied loads, allowable free play in the bearing, maximum permissible torque, material of the shaft and bearing seat, operating temperature, and which ring is rotating. Proper attention is required during the installation of Reali-Slim thin section bearings to ensure their high precision and long service life. Here are several key points for the installation of thin section bearings:

Installation Environment: Maintain a clean installation environment. Cleanliness is crucial for bearing performance. Work surfaces and tools must be free of dust, debris, and burrs. Use disposable wipes or cotton cloth for cleaning to avoid abrasive particles sticking to the bearing during mating and assembly, as even small amounts of abrasive particles and debris can significantly affect bearing accuracy.

Fit between Bearing and Shaft: For thin section bearings, care must be taken in handling the interference fit between the installation hole and the shaft to avoid damaging the bearing. Using temperature differences to expand external components reduces or eliminates installation force. Bearings and shafts made of different materials (such as AISI 52100 steel and AISI 440C material) have different rates of expansion.

Installation Method: Choose the appropriate installation method, such as manual installation, mechanical press fit, or cold shrink fit, based on the bearing model and size, such as manual installation for small bearings and mechanical press fit for large bearings. Cold shrink fitting requires a high level of technical expertise.

Installation of Angular Contact (A Type) Bearings

Angular contact ball bearings can only withstand axial (thrust) loads in one direction, so they are almost always used in pairs. They can be arranged in a back-to-back (DB) or face-to-face (DF) configuration, as described in the bearing selection section on page 91. Angular contact bearings are typically used with a certain amount of axial preload to eliminate all free play and increase stiffness. Angular contact bearings can be purchased as matched pairs with factory-set axial preload or as individual bearings with axial preload set during installation.

Installation of C Type Thin Section Bearings

Radial (C type) bearings: Radial bearings are usually used when the applied load is predominantly radial. If using two bearings at the ends of a long shaft, one bearing should be allowed to float axially to prevent axial (thrust) forces caused by thermal expansion of the shaft or bearing seat. Aubearing typically recommends a light press fit between the bearing and the shaft or bearing seat (regardless of which side rotates). A small clearance should be left on the non-rotating (static) side. Most radial bearings have internal radial clearance. Using the recommended fit ensures that the bearing does not become radially tight after installation, which could otherwise affect bearing life and performance.

Note that the recommended fit is only applicable to bearings with "standard" clearance and for steel shafts and bearing seats or ambient temperature applications. If different metals are used, the fit will vary with temperature, possibly causing radial tightening of the bearing, resulting in excessive friction torque. When bearings have radial preload, it is recommended to leave a slight gap between the shaft and the bearing seat.

Installation of Four-Point Contact (X Type) Bearings

Four-point contact (X type) bearings: X-type bearings are used when applying axial (thrust) loads or a combination of radial, thrust, and moment loads. If using two bearings at the ends of a long shaft, the second bearing should be a radial (C type) bearing, and its floating should be allowed. Like radial bearings, the fit is only suitable for bearings with standard clearance, steel shafts and bearing seats, or ambient temperature applications. Four-point contact bearings can also provide radial preload. When using preload bearings, a small gap should be left between the shaft and the bearing seat. A single four-point contact bearing can withstand axial (thrust) loads in two directions. It can also withstand radial and moment loads. However, this type of bearing typically has higher frictional forces than the same size radial (C type) or angular contact (A type) bearings. Therefore, for torque-sensitive and high-speed applications, dual angular contact bearings are often used instead of a single four-point contact bearing.

Note: If the shaft direction is within 45° of the vertical direction, the radial (C type) and four-point contact (X type) bearings with cartridge or crown-type ball separators should be installed with the solid face of the separator facing up and the grooves facing down. These bearings are marked with an "up" arrow to indicate the correct direction. For horizontal shafts, there is no preferred direction.

Applications of Reali-Slim® Thin Section Bearings

Reali-Slim® thin section bearings are widely utilized in aerospace, automotive, medical equipment, robotics, and high-speed railway industries due to their lightweight, compact, efficient, high-speed, long-life, and reliable characteristics. As technology continues to advance and application demands increase, thin section bearings will continue to play a crucial role in driving development and innovation across various fields.

Aerospace: Due to their lightweight and high efficiency, Reali-Slim® thin section bearings are extensively employed in the aerospace sector for rotating components of aircraft and spacecraft, such as engines, spindles, and transmission systems.

Automotive Industry: Reali-Slim® thin section bearings find wide application in critical parts of the automotive industry, including engines, transmissions, and suspension systems, aiming to enhance vehicle performance and reliability.

Medical Equipment: Owing to their compact size and precision manufacturing, Reali-Slim® thin section bearings are widely used in various medical equipment, such as surgical instruments, diagnostic devices, and therapeutic equipment.

Robotics: With the continuous advancement of robotics technology, Reali-Slim® thin section bearings are widely applied in robot joints and rotating mechanisms to improve robot performance and stability.

Precision Machinery: Reali-Slim® thin section bearings are suitable for various precision machinery applications, including precision machine tools and instruments.