1228 Self Aligning Ball Bearing 140mm ID 250mm OD 52mm Width For Heavy Machinery

1228 Self-Aligning Ball Bearing 140mm ID 250mm OD 52mm Width For Heavy Machinery

I. Product Structural Design

(1) Rolling Elements and Raceways

(2) Cage

II. Key Product Parameters

III. Material Selection

• Bearing Steel: The inner/outer rings and steel balls are made of high-carbon chromium bearing steel (GCr15). After quenching at 830-860℃ and tempering at 160-180℃, the hardness reaches HRC60-65, which has excellent wear resistance and contact fatigue strength, and can bear long-term high-frequency loads without being easily peeled off.
• Cage: Steel plate cages are suitable for dry and normal temperature environments with low cost; nylon cages are resistant to acid and alkali corrosion, perform more stably in environments with humidity > 80%, and are lightweight with low inertia, suitable for medium and high-speed scenarios.

IV. Performance Advantages

• Super Strong Self-Aligning Ability: The spherical outer ring design can compensate for angular deviations within 3°. In equipment such as fans and pumps that are prone to shaft deflection, it can significantly reduce the additional stress of the bearing and extend the service life by more than 30%.
• High Radial Load-Carrying Capacity: The distribution of double-row steel balls enables uniform dispersion of radial loads, and the load-carrying capacity is 50% higher than that of single-row bearings of the same size, suitable for heavy-load equipment such as cranes and rolling mills.
• Low Vibration and Low Noise: The precise cooperation between the precisely processed rolling elements and raceways results in a vibration velocity level ≤ 28dB during operation, which performs excellently in noise-sensitive scenarios such as textile machinery and medical equipment.
• Strong Environmental Adaptability: It supports various sealing forms (open, 2RS, ZZ). The 2RS sealed model can effectively block dust and water vapor (protection grade IP54), adapting to dusty and humid environments such as mines and papermaking.

V. Application Fields

• Heavy Industry Equipment: Used in rolling mill roller tables, crane slewing mechanisms, mining crushers, etc., to bear large radial loads and compensate for installation errors.
• General Machinery: Adapted to the transmission shafts of large fans, water pumps, and reducers, alleviating shaft deflection problems caused by equipment operation.
• Textile and Papermaking: In textile machine spindles and papermaking machine press rolls, it ensures continuous operation of equipment with low noise and self-aligning performance.
• Shipbuilding and Metallurgy: Used in ship propulsion systems and metallurgical continuous casters, it can withstand vibration and impact loads and adapt to harsh working conditions.

VI. Installation and Maintenance Points

• Installation Points:
  • Before installation, clean the journal and bearing housing bore, with surface roughness ≤ Ra1.6μm to avoid early wear caused by impurities.
  • Use the temperature difference method for installation: heat the bearing to 80-100℃ (not exceeding 120℃), or cool the shaft to -20~-30℃; direct knocking on the inner ring is prohibited.
  • After installation, check the axial movement, which should be controlled within 0.1-0.3mm to ensure a tight fit between the bearing and the shafting.
• Lubrication Points:
  • For conventional working conditions, fill with NLGI Grade 2 lithium-based grease, with a filling amount of 1/3-1/2 of the internal space of the bearing; for high-temperature working conditions (> 100℃), use polyurea-based grease instead.
  • For oil lubrication, a pressure oil supply system is required. The recommended oil viscosity is ISO VG46-68, and the oil supply pressure is 0.1-0.3MPa.
• Maintenance Points:
  • Check the lubrication status every 1000 hours of operation; in dusty environments, it should be shortened to 500 hours.
  • Monitor the bearing status with a vibration detector. When the vibration acceleration > 2.5g, stop the machine for inspection to avoid expanding the fault.
  • Outdoor equipment should be equipped with rain shields to prevent rainwater from entering the bearing and causing rust.