6304-2RS Bearing 20x52x15 Double Sided Rubber Seal Bearings Deep Groove

6304-2RS Deep Groove Ball Bearing With Rubber Seals For Motors & Appliances
The 6304 - 2RS bearing is a key component in mechanical engineering, belonging to the deep - groove ball bearing category with double - sided rubber seals (2RS). This design enables it to excel in various operating environments, especially those requiring protection against contaminants like dust, dirt, and moisture. This product introduction will comprehensively cover its design structure, performance parameters, material quality, application fields, and installation and maintenance guidelines.
I. Design and Structure
Inner Ring and Outer Ring
The inner ring of the 6304 - 2RS bearing is precisely machined to fit a 20 - mm shaft. Its smooth inner surface ensures a tight and stable connection with the shaft, minimizing slippage during operation and facilitating efficient power transmission. The outer ring has an outer diameter of 52 mm, designed to withstand external forces effectively. Both the inner and outer rings are equipped with deep, accurately crafted raceways that guide the rolling elements, ensuring smooth and even movement of the steel balls. These raceways allow for optimal contact between the balls and the rings, distributing loads evenly and reducing stress concentrations, thus enhancing the bearing's durability.
Rolling Elements and Cage
At the core of the 6304 - 2RS bearing are high - precision steel balls made from top - grade bearing steel. These balls undergo rigorous manufacturing processes, including precise grinding to achieve an ultra - smooth surface finish. This smoothness allows them to roll effortlessly within the raceways, reducing friction and ensuring efficient operation. The cage, usually made of sheet metal, maintains the proper spacing between the balls, preventing collisions that could lead to premature wear. It also guides the balls along the raceways, ensuring consistent rotation and aiding in lubricant distribution, which further improves the bearing's performance and lifespan.
Sealing Structure
The "2RS" in the 6304 - 2RS bearing designation indicates the presence of double - sided rubber seals. These seals are a key feature, providing a reliable barrier against dust, dirt, and moisture. The rubber seals fit snugly around the inner and outer rings. In dusty environments, they prevent fine particles from entering and causing abrasive wear. In humid conditions, they keep moisture out, avoiding corrosion of internal components. This high - level protection is crucial in challenging operating environments. Though they introduce slightly more friction than non - contact seals, the trade - off is worthwhile for contamination prevention.
II. Key Parameters

III. Performance Advantages
High Radial Load - Carrying Capacity
The 6304 - 2RS bearing is designed to handle moderate to heavy radial loads effectively. Its deep - groove structure and high - quality steel balls work together to distribute radial forces evenly across the bearing components. This even load distribution allows it to withstand the radial pressures encountered in various medium - duty applications, such as industrial machinery and power tools, ensuring stable operation over extended periods.
Axial Load Accommodation
In addition to radial loads, the 6304 - 2RS bearing can accommodate a certain amount of axial loads in both directions. The design of the raceways and the contact angle between the balls and the raceways enable it to handle these axial forces, making it versatile for applications where there are forces acting along the shaft, such as in electric motors and gearboxes.
Low Friction and High - Speed Capability
Despite the rubber seals, the 6304 - 2RS bearing is engineered to have low friction. The smooth - rolling steel balls and well - designed cage minimize the friction coefficient, reducing energy consumption. This low friction also allows the bearing to operate at high speeds, with limiting speeds ranging from 12000 to 17000 rpm depending on the lubrication method. It is thus suitable for high - speed applications like pumps and fans.
Quiet Operation
The 6304 - 2RS bearing is optimized for quiet and low - vibration operation. The precision - made components, including the smooth steel balls and balanced cage, reduce vibrations and noise during rotation. The rubber seals also help dampen vibrations, making it an ideal choice for applications where quiet operation is essential, such as in household appliances and medical equipment.
IV. Material Quality
Material of Rings and Balls
The rings and balls of the 6304 - 2RS bearing are made from high - grade high - carbon chromium bearing steel. This steel undergoes strict quality control, including vacuum degassing to remove impurities, ensuring high density and excellent mechanical properties. The balls are formed through cold - heading and heat - treatment processes like quenching and tempering, resulting in a uniform internal structure, high hardness, and good wear resistance, which enhance the bearing's fatigue resistance and service life.
Cage Material
The cage is typically constructed from sheet metal, which offers a good balance of strength and cost - effectiveness. It can withstand the centrifugal forces and interactions with the balls during operation, ensuring the balls remain properly spaced and guided. The sheet metal cage also has good thermal conductivity, aiding in heat dissipation to maintain stable performance.
V. Application Fields
Industrial Machinery
In industrial machinery, the 6304 - 2RS bearing is used in medium - sized equipment such as conveyors, pumps, and small machine tools. Its ability to handle radial and axial loads, along with its contamination resistance, makes it suitable for these applications, ensuring smooth operation and long service life.
Electric Motors
It is a common choice for medium - power electric motors, such as those in industrial fans and machine tools. The bearing can withstand the radial forces from the rotor and accommodate minor axial movements, contributing to the motor's efficient and reliable operation.
Automotive Industry
In the automotive sector, the 6304 - 2RS bearing is used in components like water pumps and alternators. Its good load - handling capacity and sealing properties make it suitable for these applications, ensuring reliable performance in the vehicle's environment.
Household Appliances
Widely used in household appliances such as washing machines, dryers, and large fans, the 6304 - 2RS bearing's quiet operation, high - speed capability, and contamination resistance make it ideal for these devices, enhancing their performance and durability.
VI. Installation and Maintenance
Installation
Proper installation is crucial for the 6304 - 2RS bearing's performance. Use appropriate tools like a bearing press or installation sleeve to ensure even installation without damaging the bearing. Align the bearing correctly with the shaft and housing to avoid uneven loading, which can cause premature wear. For tapered shafts, use a locking nut to adjust the pre - load, ensuring optimal stiffness and vibration reduction.
Maintenance
Regular maintenance involves proper lubrication. Use lithium - based grease for general applications, filling it to one - third to one - half of the bearing's internal space. For high - speed or high - temperature applications, use ISO VG 32 or 46 oil. Monitor the bearing's temperature (typically not exceeding 60 - 80°C) and check for abnormal vibration or noise, which may indicate wear or misalignment. Promptly replace contaminated or degraded lubricant and inspect the bearing regularly to prevent failures.
VII. Conclusion
The 6304 - 2RS bearing is a reliable and versatile component, offering excellent performance in various applications. Its suitable size, good load - handling capacity, contamination resistance, and quiet operation make it an essential part of many mechanical systems. By understanding its design, performance, and maintenance requirements, users can maximize its effectiveness, ensuring efficient and long - lasting operation in their equipment.