Ball Bearing With Annular Outer Spherical Surface

1. Product Overview​

Spherical ball bearings with annular housings are standardized integrated support components in the field of mechanical transmission. Composed of a spherical outer ball bearing main body and an annular bearing housing through precise matching, they are designed and manufactured in strict compliance with national standards such as GB/T 7810-1995 (Spherical Outer Ball Bearings) and GB/T 7809-1995 (Bearing Housings). Their core value lies in combining the self-aligning capability of the spherical outer structure with the lightweight and space adaptability advantages of the annular housing. They provide stable combined load support (primarily radial load, supplemented by axial load) for the shafting of small and medium-sized mechanical equipment, and are widely suitable for industrial scenarios with limited installation space and lightweight requirements. They serve as core support components in fields such as fans, motors, and light industrial equipment.​

2. In-depth Analysis of Product Structure​

(1) Spherical Outer Ball Bearing Main Body​

Core Structure: It adopts a modified design of deep groove ball bearings. The outer diameter surface of the outer ring is precision-ground into a standard spherical shape, forming a clearance fit with the concave spherical surface of the annular housing (the fit clearance is standardized by model, usually 0.02-0.05mm). This fitting structure is the core for realizing the automatic self-aligning function. The bearing interior includes high-precision steel balls (diameter tolerance ±0.002mm), stamped steel plates or engineering plastic cages (commonly PA66 material, temperature resistance -30℃ to 120℃), and an inner ring treated with quenching and tempering (hardness HRC60-65). The inner diameter surface of the inner ring is provided with oil grooves to facilitate the storage and distribution of grease.​

Functional Characteristics: When the shaft deflects (maximum allowable deflection 0.1-0.3mm) or there is an installation coaxiality error (≤2.5°) during equipment operation, the spherical surface of the outer ring can slide slightly along the concave spherical surface of the housing, automatically compensating for deviations. This avoids local stress concentration on the bearing, reduces wear rate, and extends service life.​

(2) Annular Bearing Housing​

Structural Design: The housing is annular in overall shape (the ratio of annular inner diameter to outer diameter is usually 1:1.5-1:2). Compared with traditional circular housings, its weight is reduced by 20%-30%, significantly optimizing the overall weight of the equipment. 2-4 bolt holes (aperture tolerance H9) are evenly distributed along the circumferential direction of the housing, with a hole center distance deviation ≤0.1mm to ensure balanced force bearing during installation. Some models are equipped with positioning grooves (width tolerance H10) on the inner side of the annular housing, which can be matched with the positioning boss of the equipment base to achieve a positioning accuracy of ≤0.05mm and prevent the housing from shifting during operation. A grease filling hole is provided on the top of the housing, equipped with a dust-proof plug for easy later maintenance and grease replenishment.​

Installation Adaptability: The annular structure is not only suitable for flat installation surfaces but also can be installed on the outer wall of tubular equipment (such as ventilation ducts and conveying pipes) by means of bolt penetration fixing or welding auxiliary fixing. It is suitable for tubular carriers with a diameter of 50-200mm, solving the problem that traditional bearing housings have strict restrictions on the shape of the installation surface.​

3. Performance Parameters and Core Advantages​

(1) Key Performance Parameters​

Load-bearing Capacity: It mainly bears radial loads and can bear axial loads that are 1/3-1/2 of the radial load. The range of rated radial dynamic load is 2.5-18kN (for example, the rated dynamic load of the UCFA204 model is 5.2kN, and that of the UCFA206 model is 10.8kN). It is suitable for medium and light load working conditions of small and medium-sized equipment (the actual load is recommended not to exceed 70% of the rated load to ensure a safety margin).​

Speed Performance: Under the conditions of sufficient lubrication (grease filling volume is 1/3-1/2 of the internal space of the bearing) and ambient temperature ≤80℃, the limiting speed can reach 3000-6000r/min (micro-models such as UCFA102 can reach 6000r/min, and conventional models such as UCFA205 are approximately 4500r/min), which meets the speed requirements of household motors, small fans and other equipment.​

Sealing Performance: Double-sided contact seals (model suffix 2RS) are used by default. The seal ring is made of nitrile rubber (NBR) or fluororubber (FKM, temperature resistance -20℃ to 200℃). The seal lip fits closely with the inner ring seal groove, achieving an IP54 dust and water resistance rating. It can effectively block the intrusion of dust (particle size ≥10μm) and water vapor, and can operate stably in an environment with humidity ≤90% and dust concentration ≤10mg/m³.​

Service Life: Under standard working conditions (radial load is 40% of the rated dynamic load, speed 2000r/min, regular lubrication), the rated service life can reach 8000-12000 hours; if stainless steel material and enhanced sealing are adopted, the service life can be extended by 30%-50%.​

(2) Core Advantages​

Space and Weight Optimization: The lightweight design of the annular housing reduces equipment load and installation space occupation. It is particularly suitable for scenarios sensitive to weight and space, such as portable equipment and suspended fans. Compared with equipment with circular housings of the same specification, the installation space can be saved by more than 25%.​

Flexible Installation Scenarios: It breaks through the restrictions of traditional housings on the installation surface, and can be fixed on installation surfaces of various shapes such as flat surfaces and tubular carriers. Moreover, the bolt holes are standardized, suitable for standard bolts of M6-M12 specifications, without the need for customized installation accessories, improving installation efficiency by 40%.​

Low Maintenance Cost: The bearing and the housing adopt a separable design. When the bearing is worn or the housing is damaged, the damaged part can be replaced individually without overall scrapping, reducing maintenance costs by 50%-60%. The grease filling hole design of the housing facilitates regular grease replenishment, which can be completed without disassembly, reducing equipment downtime.​

Strong Environmental Adaptability: Multiple combinations of seals and materials are available. The basic model is suitable for normal temperature and dry environments, while the stainless steel + FKM seal model can be adapted to environments with a temperature range of -20℃ to 200℃ and slight corrosion (such as weak acid and weak alkali mist), meeting the needs of special scenarios such as food processing and sanitary equipment.

(2) Manufacturing Process​

Bearing Manufacturing:​

Outer Ring/Inner Ring: The process of cold heading forming → spheroidizing annealing (temperature 780-820℃, holding time 4 hours) → rough grinding → quenching (temperature 850-870℃, oil cooling) → tempering (temperature 180-200℃, holding time 2 hours) → precision grinding is adopted to ensure dimensional accuracy (inner diameter tolerance g5, outer diameter tolerance h6) and surface roughness (Ra ≤0.4μm).​

Assembly: A fully automatic assembly line is used. After the steel balls are sorted by a screening machine (accuracy ±0.001mm), they are accurately assembled with the cage, inner ring, and outer ring. Finally, the seal ring is press-fitted. After assembly, rotation flexibility testing (starting torque ≤0.5N·m) and sealing performance testing (water pressure 0.1MPa, no leakage for 30 seconds) are carried out.​

Annular Housing Manufacturing:​

Gray Cast Iron Housing: Sand casting (casting temperature 1380-1420℃) → aging treatment (temperature 200-250℃, holding time 8 hours, eliminating internal stress) → CNC milling (processing bolt holes and positioning grooves) → surface painting (epoxy resin paint, thickness 60-80μm, salt spray resistance for 48 hours).​

Stainless Steel Housing: Precision casting (investment casting process, dimensional tolerance CT6) → CNC turning → polishing (surface roughness Ra ≤1.6μm). No painting is required, and corrosion resistance is achieved directly.

5. Main Application Fields

With its advantages of lightweight and strong space adaptability, spherical ball bearings with annular housings are widely used in small and medium-sized equipment in various fields:​

Ventilation and Air Conditioning Equipment: Suitable for ventilation duct fans with a diameter of 80-150mm. The annular housing is installed on the outer wall of the duct to save internal space, and the double-sided seal blocks dust to ensure the continuous operation of the fan;​

Small Conveying Equipment: Used for supporting the roller shaft of light belt conveyors (conveying capacity ≤50kg/m). The lightweight design reduces equipment load, and it is suitable for tubular or flat installation surfaces;​

Household and Industrial Motors: Suitable for motors with a power of 0.5-3kW (speed 1500-3000r/min), such as washing machine motors and small water pump motors. It saves space in the motor housing and operates with noise ≤55dB;​

Light Industrial Packaging Machinery: Supports the transmission roller shaft of small edge banding machines and labeling machines. The stainless steel model can be adapted to the humid environment of food packaging workshops, extending the service life of the equipment.

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