Open bearings

An Open bearing usually operates in an environment where the bearing is immersed in fluids such as lubrication oil. Open bearings do not have seals or shields and they expose the inner raceways, cages, and balls to the environment. Examples would be open bearings used to support shafts in gearboxes and transmissions where lubrication is constant and present.

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Shielded Bearings

A shielded Bearing is used in any environment where contamination is not a major issue. Usually specified for applications where the designer desires low starting and running torque as well as enclosing the bearing limiting the ingress of minor contaminants such as dust.

Shielded bearings are often found in electric motors, fans, power tools, and office machinery. The shield has no contact with the inner ring where a small gap exists allowing for low starting and running torque. Shielded bearings are commonly specified with oil lubrication and usually starting and running torque is a consideration.

Sealed Bearings

Manufacturers use various designs for achieving the proper fitment and the degree of protection provided by the seal.

Why specify one over enclosure type of another and why is it important?

Bearing seals have two main functions: to prevent lubricating oil from leaking out and to prevent dust , water and other contaminants from entering the bearing. Bearings have to be adequately lubricated to prevent direct metallic contact between the rolling elements, raceways and cages to prevent wear and to protect the bearing surfaces against corrosion.

Sealed Bearings 

Bearings with shields or seals filled with grease are widely used. Grease has the advantage over oil that its more easily retained and takes longer to be compromised than oil.

Sealed bearings have the advantage of being lubricated for life, are suitable for normal and light loads with moderate to low speeds. Sealed bearings generally have a low production cost and maintain no need for relubrication or greasing.

As such these bearings are used widely in electric motors, fan motors, and automation equipment.

Seal Types

When selecting a seal the following factors need to be taken into consideration:

• the type of lubricant( oil or grease)
• seal peripheral speed
• shaft fit
• space constraints
• seal friction

As mentioned seals are broken down into non-contact and contact types.

Non-Contact Seals and Shields

Non contact seals and Shields will demonstrate a small gap between the inner diameter of the seal/shield and the inner ring of the bearing. In order to improve the seal the gap is filled in with lubricant.

Contact Seals

Contact seals accomplish their sealing action through contact pressure ( the lip) which is made of Buna N rubber normally. Contact seals are by far the best way to seal a bearing.

Being far superior contact seals are efficient, although they demonstrate higher friction torque and result in temperature rise coefficients being higher. When the portion of a contact seal rotates while in contact with the shaft the allowable seal peripheral speed varies depending on seal type.

Lubrication is necessary at the contact surface between the lip portion of the contact seal and the shaft. Ordinary lubricant can be used for this purpose.

As demonstrated the most commonly specified types of enclosures for bearings are:

• rubber seals
• steel shields
• open

In some cases your application may require an OPEN bearing to have a seal on one side and be open on the other side. A seal may be required on the outside facing the environment and the open side is facing inward. 

The reason may be to reduce drag or starting and running torque while still protecting the bearing. 

The challenge for sealing bearings is to seal the bearing by protecting the bearing from contaminants and running efficiencies.

Advantages of Sealed Bearings 

Sealed bearings offer multiple benefits in various applications:

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Contamination Protection
Sealed bearings are particularly effective at preventing external contaminants, such as dust, dirt, and moisture, from entering the bearing. This is essential in environments where contamination can significantly reduce bearing life.

Lubrication Retention
They are designed to retain the lubricant inside the bearing. This helps in maintaining the correct amount of lubrication throughout the bearing's service life, thus reducing the need for regular maintenance and relubrication.

Extended Bearing Life
By preventing contamination ingress and retaining lubrication, sealed bearings can significantly extend the bearing life compared to their open counterparts.

Reduced Maintenance
The sealed design minimizes maintenance intervals, providing cost and time savings.

Versatility
Sealed bearings are suitable for a wide range of applications, especially where external contamination is a major concern.

Difference Between Bearing Shields and Bearing Seals 

Bearing shields and seals are both designed to protect bearings from external contaminants and retain lubrication, but there are distinct differences:

• Construction
  Shields are typically made of metal and fit into a groove on the outer ring without making contact with the inner ring. Seals, on the other hand, are made of elastomeric material and make light contact with the inner ring, providing a barrier.

• Protection Level
  Seals offer a higher degree of protection from contaminants and moisture due to their contact nature. Shields provide protection primarily from larger contaminants but are less effective against fine particles and moisture.

• Friction
  Since seals have contact with the inner ring, they generate more friction than shields. This may result in slightly higher operating temperatures for sealed bearings compared to shielded ones.

• Lubrication
  Sealed bearings are often pre-lubricated, making them maintenance-free for many applications. Shielded bearings might need occasional relubrication.

Comparison Between Sealed and Shielded Bearings 

The choice between sealed and shielded bearings will depend on the specific requirements of the application. While sealed bearings offer superior protection and maintenance advantages, shielded bearings can be more suitable in situations where minimal friction and operating temperature are crucial. It's essential to assess the operational environment and demands before making a selection.

Exploring the Advantages and Disadvantages of Different Bearing Types

Introduction

Bearings are essential components in countless mechanical systems, enabling smooth and efficient rotational or linear motion between parts. With a wide array of bearing types available, selecting the appropriate one can significantly impact a machine's performance, reliability, and lifespan. In this article, we will delve into the advantages and disadvantages of some of the most common bearing types, providing valuable insights to guide informed decision-making.

Ball Bearings

Advantages:

1. Low friction and smooth operation
2. High load-carrying capacity
3. Versatility for various applications
4. Relatively inexpensive and widely available

Disadvantages:

1. Limited tolerance for misalignment
2. Susceptibility to vibration and noise at high speeds
3. Potential for denting or deformation under extreme loads

Roller Bearings

Advantages:

1. Exceptional radial and thrust load capacity
2. Ability to accommodate misalignment
3. Reduced friction and wear compared to plain bearings
4. Suitable for high-speed applications

Disadvantages:

1. Higher cost compared to ball bearings
2. Increased complexity and maintenance requirements
3. Sensitivity to lubrication quality and contamination

Plain Bearings

Advantages:

1. Simple design and construction
2. Cost-effective for low-speed, low-load applications
3. Ability to operate in harsh or contaminated environments
4. Good damping characteristics for vibration reduction

Disadvantages:

1. Higher friction and wear compared to rolling bearings
2. Limited load-carrying capacity
3. Potential for seizing or galling under insufficient lubrication
4. Shorter lifespan in demanding applications

Magnetic Bearings

Advantages:

1. Virtually frictionless operation
2. No mechanical contact, reducing wear and contamination
3. High rotational speeds without excessive heating
4. Active control for vibration dampening and precision positioning

Disadvantages:

1. Complex and expensive design
2. Reliance on external power source and control system
3. Limited load-carrying capacity compared to mechanical bearings
4. Sensitivity to external magnetic fields

Air Bearings

Advantages:

1. Extremely low friction and wear
2. Exceptional precision and stiffness
3. Suitable for clean-room environments
4. Ability to handle high speeds and loads

Disadvantages:

1. Complexity of the air supply and control system
2. Potential for air consumption and leakage
3. Limited load capacity compared to mechanical bearings
4. Sensitivity to contamination and air quality

Conclusion

Choosing the appropriate bearing type is crucial for ensuring optimal performance, efficiency, and longevity in mechanical systems. Each bearing type offers unique advantages and limitations, requiring careful consideration of factors such as load capacity, speed, alignment, environmental conditions, and cost. By understanding the strengths and weaknesses of different bearing types, engineers and designers can make informed decisions that balance performance requirements, operating conditions, and budgetary constraints. Ultimately, selecting the right bearing can contribute to the overall reliability, safety, and cost-effectiveness of mechanical systems across various industries.

Different types of bearing products

Cross Roller Bearings Slewing Ring Bearings Robot Reducer Bearings Rotary Table Bearings Thin Section Bearings Ball Screw Support Bearings Angular Contact Ball Bearings Hollow Rotary Platform Bearings Cross Roller Bearings Slewing Ring Bearings Robot Reducer Bearings Rotary Table Bearings Thin Section Bearings Ball Screw Support Bearings Angular Contact Ball Bearings Hollow Rotary Platform Bearings

About LKPB Precision Bearing Manufacturer

Luoyang LIKE Precision Machinery Co., Ltd ' LKPB®, Located in Luoyang, China, Established in with a registered capital of 5 million, We are a professional bearing manufacturer.

LKPB strictly follows the ISO quality system requirements for product quality control, we have a strong technical team to accept processing of non-standard precision bearings of P5, P4, P2 and VSP level of accuracy. The products inner diameter size range is φ20mm-φmm.

We have established long term co-operation with a number of the world's leading machine tool and robotics companies, the products can completely replace of INA/IKO/THK/FAG/SKF/KAYDON and other brands. We believe that cooperating with us will exceed your expectations.

1. Rotary Table Bearings ( YRT, YRTC, YRTS, YRTM, ZKLDF Series) ;

2. Cross Roller Bearings ( RA/RA-C, RAU, RB, RU, RW, RE, SX, XU, XV, XSU, XR/JXR, CRB/CRBC, CRBF/CRBFV, CRBH/CRBHV, CRBS/CRBSV, CRBT/CRBTF Series);

3. Thin Section Bearings ( KAA, KA, KB, KC, KD, KF, KG, JHA, JA, JB, JG, JU Series);  

4. Robot Reducer Bearings (CSF/CSG, SHF/SHG, CSD Series, RV Reducer Bearings and Flexible Bearings F, 3E Series);

5. Angular Contact Ball Bearings ( 718, 719, 70, 72, / Series);  

6. Ball Screw Support Bearings ( ZKLF/ZKLN, ZARF/ZARN Series);

7. Slewing Ring ( Cross Roller, Four-Point Contact, Eight-Point Contact Same Path, Eight-Point Contact Different Path, Three-row roller and Flanged Series);

8. Hollow Rotary Platform Bearings ( ZK Series).

For expert guidance in meeting your specific requirements, reach out to our knowledgeable team. Experience firsthand how our precision solutions can elevate your machinery's efficiency and durability. Contact us today!

LKPB With more than 10 years of production experience

Supporting OEM service; 50 days return service; 7*24 hours technical support; Accept non-standard customization; Maximum 24 months product warranty

The company is the world’s best Thrust Roller Bearings manufacturer supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

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