Ball Bearing With Suspended Top Cap And External Spherical Surface

Pillow block ball bearings with suspension housing and set screw are standardized rolling bearing units designed specifically for suspended shaft support scenarios. They are mainly integrated with set screw-locked pillow block ball bearings and dedicated suspension housings, with typical models represented by the SA series (e.g., SA200 series). The original design intention is to address installation scenarios that traditional floor-mounted bearing housings cannot adapt to, such as "equipment tops, beam bottoms, and lateral suspension". Meanwhile, the set screw structure enables quick fastening between the bearing and the shaft, and the bearings also feature self-aligning compensation capability and easy maintenance. They are widely used in suspended transmission equipment with light to medium loads and medium to low speeds.​

This product undergoes pre-lubrication (filled with long-acting lithium-based grease) and sealing treatment before leaving the factory. The integrated structure requires no additional assembly and can be directly matched with transmission systems with shaft diameters ranging from 10 mm to 80 mm. It is suitable for normal working conditions of -30℃ to 120℃, serving as an efficient solution for suspended shaft support.

(1) Three Core Components​

Set Screw-Locked Pillow Block Ball Bearing​

Bearing Inner Ring: 1-2 set screw holes (with hole positions distributed at 90° or 180°) are machined on the inner diameter surface of the inner ring. It is equipped with high-strength set screws (made of quenched 45# steel). After being screwed in, the set screws can directly press against the shaft journal to achieve rigid connection between the bearing and the shaft, preventing relative sliding. The inner ring is made of high-carbon chromium bearing steel (SUJ2) with a hardness of HRC 60-62, ensuring wear resistance and rotational accuracy.​

Bearing Outer Ring: The outer diameter surface has a precision spherical structure, which forms a clearance fit with the inner spherical surface of the suspension housing. It can achieve automatic self-alignment of 2°-5°, effectively compensating for coaxiality errors during shaft installation (such as deviations caused by shaft bending or housing misalignment) and avoiding local overload jamming of the bearing.​

Rolling Elements and Cage: The rolling elements are SUJ2 bearing steel balls (or optional ceramic balls) with super-finished and ground surfaces. The cage is made of stamped steel plate (or engineering plastic), which can stably guide the movement of rolling elements, reduce the friction coefficient, and adapt to a maximum speed requirement of 3000 r/min.​

Suspension Bearing Housing​

Structural Design: The housing has an overall "L"-shaped or "inverted U"-shaped hanging structure. 2-4 bolt mounting holes (with hole diameters matching M8-M20 bolts) are reserved on the top or side of the housing, allowing direct fixation on suspended carriers such as equipment beams and rack bottoms via bolts. A spherical groove matching the outer ring of the bearing is machined inside the housing, and a positioning step is set at the bottom of the groove to ensure accurate radial positioning of the bearing after installation.​

Material Selection: The mainstream material is gray cast iron HT200 (casting process), which has high strength (tensile strength ≥ 200 MPa), good shock absorption, and cost advantages, making it suitable for most industrial scenarios. For special heavy-load scenarios, cast steel (e.g., ZG230-450) can be selected, which has a tensile strength increased to over 450 MPa to cope with impact loads. For lightweight demand scenarios, aluminum alloy material (e.g., 6061-T6) can be used, with the weight reduced by 40% compared to cast iron housings.​

Sealing and Lubrication System​

Sealing Device: It is equipped with a standard double-layer sealing structure. The inner layer is a nitrile rubber (NBR) sealing ring (oil-resistant, temperature-resistant from -30℃ to 120℃), which is closely attached to the dust-proof groove of the bearing inner ring to block dust intrusion. The outer layer is a metal oil slinger (rotating with the bearing outer ring), which can form a centrifugal air flow to throw external liquids and impurities away from the bearing while preventing the leakage of internal lubricating grease. The protection level reaches IP54 (dust-proof and splash-proof), and can be upgraded to IP65 protection (fully dust-proof and water-jet proof) for special scenarios.​

Lubrication Configuration: It is pre-filled with high-quality lithium-based grease (e.g., Great Wall 7019-1), which has good high and low-temperature stability and shear resistance. Under clean indoor working conditions, it can achieve 1500-2000 hours of maintenance-free grease replenishment. An oil nozzle (matching M10×1 or 1/4-28 UNF threads) can be optionally installed on the side of the housing. Under harsh working conditions, lubricating grease can be replenished regularly to extend the service life of the bearing.

(2) Key Material Parameters Table​

Core Performance and Advantages​

(1) Strong Scenario Adaptability, Breaking Installation Limitations​

Compared with traditional floor-mounted bearing housings (which require ground or platform support), the suspension housing can be directly fixed to suspended carriers without the need for additional support structures. It is particularly suitable for scenarios such as "suspended centrifugal fan shaft support, upper transmission rollers of conveyors, and lateral auxiliary shafts of equipment", saving equipment space and installation costs.​

(2) Efficient Set Screw Fastening, Low Assembly Difficulty​

The set screw fixing method eliminates the need for complex adjustments of eccentric sleeves (e.g., UK series bearings) or nut locking processes of adapter sleeves (e.g., UB series bearings). After sleeving the bearing onto the shaft journal, simply tightening the set screws with a wrench completes the fixation. A single person can assemble one set within 10 minutes, with efficiency improved by over 30% compared to traditional structures. Additionally, the set screw holes are symmetrically positioned, ensuring uniform fastening force and preventing shaft journal deformation due to uneven force.​

(3) Accurate Self-Aligning Compensation, More Stable Operation​

The spherical fit between the bearing outer ring and the housing can automatically compensate for shaft installation deviations (e.g., coaxiality error ≤ 0.5 mm, angle deviation ≤ 5°), avoiding local hard contact between the bearing inner ring and the shaft, and between the outer ring and the housing. This reduces friction loss and vibration noise (operating noise ≤ 65 dB) and extends the bearing service life (average service life reaches 8000-12000 hours, an increase of 50% compared to structures without self-alignment).​

(4) Balanced Protection and Maintenance, Reducing Operation and Maintenance Costs​

The double-layer sealing and pre-lubrication design significantly reduces the intrusion of external impurities and the consumption of lubricating grease. The maintenance-free period reaches over 1500 hours under normal operating conditions. Even in dusty (e.g., textile mills, mines) or slightly splashy environments, the sealing structure can effectively protect the interior of the bearing, reducing failure rates. Moreover, the bearing and housing feature a detachable design; if the bearing is damaged, it can be replaced independently without replacing the entire housing, reducing maintenance costs by 40%.

4. Typical Application Scenarios​

With its core advantages of "suspended support + set screw fastening + self-aligning compensation", this product is widely used in the following fields:​

Ventilation and Environmental Protection Equipment: Main shaft support of suspended centrifugal fans, rotating filter cartridge shafts of dust collectors, and suspended agitator shafts of sewage treatment equipment. It can adapt to the top or lateral installation requirements of equipment and withstand dusty and humid environments.​

Textile and Light Industry Machinery: Upper yarn guide rollers of textile machines, suspended transmission rollers of printing machines, and lateral conveying shafts of packaging machines. The set screw fastening design enables quick roller replacement, improving production efficiency.​

Agricultural and Food Machinery: Suspended conveyor chain shafts of combine harvesters and top exhaust fan shafts of grain dryers. The suspension housing adapts to the compact structure of the equipment, and the sealing design blocks grain dust.​

General Machinery and Automation Equipment: Suspended guide rollers of assembly lines and lateral auxiliary transmission shafts of automated production lines. The self-aligning function can cope with minor shaft deformation after long-term equipment operation, ensuring stable transmission.​

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