Angular Contact Ball Bearing Double Row 7234FY KOYO

The KOYO 7234FY is a high-performance single-row angular contact ball bearing, engineered for combined radial and axial loads in medium-to-heavy duty industrial applications. It fully complies with ISO 355 and DIN 628 standards, with the suffix FY denoting a steel solid cage guided by rolling elements, which ensures stable operation and high load-bearing capacity. Distinguished by its optimized contact angle and robust structural design, it offers excellent high-speed stability and durability, making it a reliable choice for harsh industrial environments where precision and load capacity are critical.

1. Detailed Dimensional Parameters: Conforming to international bearing standards, the bearing has an inner diameter (d) of 170mm, outer diameter (D) of 310mm, and width (B) of 52mm. The minimum chamfer size (rₘᵢₙ) is 3.0mm, single weight is 16.7kg. Its tolerance grade is P0 (ISO 492), with inner/outer diameter tolerance of IT6 and width tolerance of IT7. The basic dynamic load rating is 272kN, basic static load rating is 330kN, reference speed (grease lubrication) is 1800r/min, and limiting speed (oil lubrication) is 2400r/min. It adopts a 15° contact angle, optimizing load distribution for combined radial and axial load scenarios.

2. Specific Material Description: Inner ring, outer ring and ball rolling elements are made of high-carbon chromium bearing steel (AISI 52100/SUJ2), refined by vacuum degassing technology to reduce non-metallic inclusions. After precision heat treatment, it reaches a hardness of 61-65 HRC, featuring excellent wear resistance, high fatigue strength and stable dimensional accuracy under cyclic loading. The retainer (suffix FY) is a steel solid cage (S45C), with good impact resistance and wear resistance, ensuring stable rolling element guidance and enhancing bearing rigidity. Optional corrosion-resistant treatments are available for harsh environments.

3. Core Processing Technology: Key manufacturing processes follow KOYO’s stringent quality standards: closed-die forging, CNC turning, controlled atmosphere heat treatment, precision grinding and superfinishing. Closed-die forging ensures dense internal structure and continuous metal fibers. CNC turning achieves Ra ≤ 0.3μm surface roughness. Heat treatment adopts nitrogen-hydrogen atmosphere to avoid oxidation and decarburization. Precision grinding with CBN砂轮 and superfinishing reduce raceway roughness to Ra ≤ 0.04μm, minimizing friction. The steel cage is precision machined to ensure tight fit with rolling elements, improving operational stability.

4. Service Life: Under standard working conditions (1500r/min, radial load 90kN, proper lubrication and clean environment), the L₁₀ basic rated life (90% reliability) is 15,000 operating hours, calculated in accordance with ISO 281:2007 standard. Key influencing factors include lubrication quality, contamination level, installation accuracy and load magnitude; insufficient lubrication or excessive contamination can reduce service life by 30-50%.

5. Application Scenarios and Industries: Widely used in machinery manufacturing, automotive, engineering machinery, rolling mills and power generation industries. Typical applications include large electric motors, gearboxes, rolling mill equipment, centrifugal pumps and heavy-duty transmission systems. It is suitable for these scenarios due to its high combined load capacity, steel cage’s rigidity, and optimized contact angle, adapting to heavy-duty, medium-speed working conditions.

6. Basic Maintenance Requirements: Maintenance cycle is 2000 operating hours. Lubrication: Lithium-based grease (NLGI 2) or extreme pressure gear oil (ISO VG 68), filling amount 15-30% of bearing free space; re-lubricate every 1500-2000 hours. Cleaning: Clean surface with clean kerosene; avoid corrosive cleaners. Regular inspection: Check for abnormal noise, temperature rise and grease leakage; replace lubricant if deteriorated.

7. Installation Precautions: Pre-installation: Keep area clean, remove burrs from shaft/housing, check fitting surface roughness (Ra ≤ 0.8μm). Installation: Apply thin oil film, press evenly on inner ring (no tapping), ensure coaxiality tolerance ≤ 0.02mm. Fastening torque: 160-190N·m for bearing seat bolts. Post-installation: Rotate manually to check jamming; measure temperature after 30 minutes (normal ≤ 72℃). Safety: Wear protective gloves/goggles, use specialized lifting tools.