When selecting the right bearing for your application, it’s important to understand the differences between open, ZZ and 2RS bearings. Each type of bearing is designed for specific uses and environments, and choosing the wrong one could lead to inefficiency, unnecessary maintenance or even equipment failure. Discover the truth behind open bearings vs. sealed bearings and rubber-sealed bearings vs. metal-shielded bearings with PGN!

In this guide, we’ll explore the key features, benefits, and best-use cases for each bearing type to help you make an informed decision. Whether you’re working on high-speed machinery, skateboards, or electric motors, this guide will point you in the right direction.

What Are Open Bearings?

Open bearings are designed without any shields or seals, exposing the internal rolling elements. This design provides easy access for lubrication and cleaning, making them ideal for certain applications where contamination is minimal.

Key Features:

• No seals or shields; internal components are exposed.
• Minimal friction, ensuring smooth and efficient operation.
• Easy to lubricate and clean, making maintenance straightforward.

Best For:

• Environments with minimal contamination where regular maintenance is possible.
• Applications that require high-speed performance, such as conveyors and robotics.

Common Uses:

• High-Speed Industrial Equipment: Open bearings are often used in conveyor belts, robotic arms, and automated assembly lines where clean environments and high speeds are critical. For instance, in the Festo Handling Systems, which use precise robotic arms, open bearings enable quick movement and minimal friction.
• Laboratory Equipment: Open bearings are ideal for use in centrifuges (like those used in Beckman Coulter or Thermo Fisher products) where regular maintenance and lubrication are easy to manage. The open design ensures minimal drag and friction, facilitating high-speed rotations in laboratory centrifuges without compromising performance.
• Clean Room Applications: Open bearings are also found in semiconductor fabrication equipment and pharmaceutical manufacturing machinery, where controlled environments and minimal contaminants are essential. For example, in equipment like KUKA Robotics, which operates in clean rooms for precise automation, these bearings ensure smooth and efficient operation with regular maintenance.

Open bearings are ideal for those who require a high-speed bearing that can be easily maintained. They are often used in applications where cleanliness is a non-issue, and friction must be kept to a minimum.

What Are ZZ Bearings?

ZZ shielded ball bearings have metal shields on both sides to protect the internal components from dust and debris. These shields provide a moderate level of protection, making them suitable for environments where light contamination is present but not ideal for harsh or wet conditions.

Key Features:

• Metal shields on both sides to block dust and debris.
• Pre-lubricated for ease of maintenance and operation.
• Minimal friction, allowing for efficient operation in moderate environments.

Best For:

• Applications in industrial machinery and equipment where light contamination may occur.
• Environments that require minimal maintenance and moderate protection against dirt.

Common Uses:

• Electric Motors: ZZ bearings are commonly used in electric motors found in HVAC systems, air compressors, and pumps. For example, the Baldor Electric Motors and Dayton Motors used in industrial applications benefit from ZZ bearings, which provide protection against dust while maintaining high rotational speeds and efficiency.
• Industrial Fans and Blowers: ZZ bearings are perfect for industrial fans and blowers used in applications like ventilation in manufacturing plants or greenhouses. A prime example is the Greenheck Fan Corporation, which manufactures ventilation systems for industrial and commercial buildings. These bearings provide protection against light contaminants while ensuring the longevity of the fan’s operation.
• Agricultural Equipment: In the agricultural industry, ZZ bearings are found in machinery like John Deere tractors and Case IH combine harvesters. These machines operate in dusty environments, making ZZ bearings a practical solution for balancing protection with low-friction efficiency.

ZZ bearings are an excellent choice when you need protection against moderate levels of debris while still maintaining low friction for efficient performance. They are typically the best bearings for electric motors and light industrial machinery.

What Are 2RS Bearings?

2RS bearings feature rubber seals on both sides to provide the highest level of protection from contaminants like dust, moisture, and dirt. This makes them perfect for applications where the bearing is exposed to harsh conditions and requires maximum protection.

Key Features:

• Rubber seals on both sides, offering superior protection from contaminants.
• Pre-lubricated and often sealed for life, minimizing the need for additional maintenance.
• Best suited for environments with high levels of dirt, dust, or moisture.

Best For:

• Harsh or wet environments where contamination is a significant concern.
• Applications where regular maintenance is difficult or impractical.

Common Uses:

• Skateboards and Rollerblades: 2RS bearings are commonly used in skateboards, rollerblades, and inline skates where exposure to dirt, dust, and water is frequent. Popular brands like Santa Cruz Skateboards and Powell Peralta use 2RS bearings in their skateboards, providing smooth, reliable performance even in rough outdoor conditions. The sealed design ensures that the bearings can withstand dirt and moisture, which are common in outdoor sports.
• Automotive Applications: In the automotive industry, 2RS bearings are frequently used in wheel hubs, suspension systems, and electric motors found in vehicles. Audi and BMW are examples of car manufacturers that rely on 2RS bearings in their vehicles’ wheel hubs, ensuring smooth and efficient operation even in wet or dirty conditions.
• Heavy Industrial Machinery: Construction equipment like Caterpillar bulldozers, Komatsu excavators, and Volvo dump trucks often rely on 2RS bearings for their heavy-duty applications. These machines operate in extreme conditions, with exposure to mud, dirt, and water, making the sealed bearings essential for long-lasting, low-maintenance performance.
• Mining Equipment: In mining, machinery such as Joy Global mining trucks, Sandvik drills, and Caterpillar loaders use 2RS bearings to protect against dust and moisture in harsh conditions. These sealed bearings ensure the smooth operation of essential equipment like hydraulic motors and drive shafts.

2RS sealed bearings are ideal for extreme environments where protection from contaminants is paramount. If your application requires bearings for harsh environments such as wet conditions, these sealed bearings provide the reliability you need.

Which Bearing Should You Choose?

Choosing the right bearing depends largely on your specific application and environment. Here’s a quick breakdown to help you decide between open, ZZ and 2RS bearings:

1. If you need minimal friction and have access to regular maintenance: Choose open bearings. These are perfect for high-speed applications and environments with little to no exposure to contaminants.
2. If moderate protection from debris is needed without frequent maintenance: Opt for ZZ bearings. Their metal shields offer protection while still allowing for smooth, efficient operation.
3. If your application requires maximum protection from dust, moisture, or other contaminants: Go for 2RS bearings. These sealed bearings are built to perform in tough, dirty, or wet conditions, offering a high level of reliability and longevity.

Where to Buy the Best Bearings for Your Needs

At PGN Bearings, we offer a wide selection of high-quality bearings, including open bearings, ZZ bearings, and 2RS bearings. Whether you’re looking for bearings for high-speed machinery, light industrial use, or rugged outdoor equipment, we’ve got you covered.

Our bearings are designed for precision, durability, and reliability, ensuring optimal performance across a range of applications. Explore our inventory and find the perfect bearing to meet your needs!