Bushing vs Bearing: A Detailed Guide

Machinery is eminent in almost every industry and application, but when a machine works, it has parts that move, and they need to have controlled friction. This friction can be reduced between the two moving parts by using bearings or bushings.

If you are wondering how they both differ, then this guide below features a detailed insight into bushing vs bearing. So, let's read.

What is a Bushing?

The bushing is a cylindrical component that offers loading support on the shaft, which moves in a sliding manner between the two surfaces that move. The bushing is a component with a single element and can be made of different materials. The bushing can slide on shafts and rods and create a low friction motion, offering shock absorption to reduce wear and noise.

Types of Bushings

The two different types of bushings are discussed below:

Bronze and Metal Bushings

Bronze bushings are made using cast bronze and offer a consistent structure; these bushings are used for wear protection and load-bearing applications. Bronze and metal bushings also offer the ability to withstand high temperatures. These are made using different metals or their alloys, which are composed of brass, aluminum, stainless steel, and copper.

Plastic Bushings

Plastic bushings have multiple properties like corrosion resistance and lightweight. The advanced plastic bushings can also deal with issues like heat sensitivity and softening. These bushings are good for use in humid environments, like drying facilities. They are not suitable for heavy loads and may crack.

What is a Bearing?

Bearings are used to support the shafts that rotate in the machine and support the movement of components. Bearings are designed with multiple components. They have a rolling element in a cage, which allows components to slide over one another. These bearings can easily let the surface glide over one another, and the devices can spin easily.

Types of Bearings

There are different types of bearings, and some of them are discussed below.

Ball Bearings

Ball bearings consist of a rolling element, which is a spherical ball between the bearing races. They work as a rolling element, creating a space between bearing races. They can easily spin in multiple directions due to their shape and even support combined loads.

Straight Roller Bearings

Straight roller bearings are used in cylindrical races and are suitable for high radial and high-speed applications. It has a broader contact area and hence can support heavy radial use.

Tapered Roller Bearings

Tapered roller bearings consist of rollers and rings with tapered shapes and in the form of cones. These bearings have shapes that help to handle heavy loads and combined loads.

Needle Bearings

Needle bearings have a rolling element and are composed of cylindrical rollers. These rollers help to handle radial loads in spaces that are compact.

Rod End Bearings

Rod end bearings are mechanical joints that offer angular movement between components and also support axial loads. They have spherical bearings, which are encased in a metal enclosure, allowing for rotation.

Differences Between Bushing vs Bearing

The section below highlights the differences between bushing and bearing.

Design Differences

Bushings are cylindrical components that can fit inside a housing or over a shaft and offer a sliding surface for the radial loads, which can help with angular motion.

Bearings, on the other hand, have complex designs and have rolling elements between outer and inner races. These rolling elements help with smooth movement and a high capacity to handle load.

Manufacturing Differences

Bushings are easy to manufacture as they have a very basic shape, and they can be molded, machined or extruded using metals or plastics.

Bearings, on the other hand, are intricate and need precise tolerance as they have assembling multiple components like races and rolling elements. They have advanced processes that cause surface hardening.

Material Differences

Bushings are made using plastic, rubber, or bronze and offer excellent wear resistance. Bearings are manufactured using high-strength steel, which enhances durability.

Maintenance Differences

Bushings need less maintenance, but they need timely lubrication. Bearings need regular maintenance and lubrication to stay in good shape and functional.

Cost Differences

Bushings are less expensive to manufacture or purchase and hence are opted in many applications. Bearings are expensive as they have complex structures and also cater to high-performing applications.

Applications

Bushings are used in applications where space is limited or where movement is at a low speed. Bearings are required for high-speed movements and high load bearing.

Pros and Cons

Bushings have a simple design and low cost. They are also lightweight and offer suitability for low-speed applications; however, they cannot handle misalignment, high speed, and high load capacity.

Bearings on the other hand can handle high load capacity and have a smooth operation. However, they are expensive and require high maintenance.

Factors to Consider When Choosing Between Bushings and Bearings

When selecting between bearings and bushings, some of the factors that must be taken into account are the following:

• Bushings are meant to handle fewer loads, and bearings can handle high loads; hence, you need to assess the load capacity of applications.
• Bearings are opted for applications with high-speed movement, and bushings are suitable for low or moderate-speed movements.
• Bearings offer high accuracy and hence can be chosen for applications that need accuracy and precision. Bushings have a lack of precision and low tolerance.
• Bearings are chosen for applications that need to reduce noise, and bushings are fixed; hence, they create more noise.
• The cost of bushing is less compared to the cost of bearing, and based on your application requirement, you can choose it considering the budget.

When Should a Bushing be Used Instead of a Bearing?

Choosing between bearing and bushing is based on the application requirements like lubrication, load capacity, maintenance, speed, etc. Bushings are suitable for high-load and low-speed applications because they have a larger surface area in contact with the shaft.

Moreover, bearings are easy to install and affordable. However, some materials used in bushings are known for their ability to withstand harsh conditions.

Conclusion

As you have gone through the guide above, you must have understood the difference between bearings and bushings. Keeping these factors in mind, you can select what you need for your application.

You can also get in touch with DEK to offer you suggestions by manufacturing highly accurate bearings or bushings for your requirements.

FAQs

What is a self-lubricating bearing?

Self-lubricating bearings are such types of bearings that have liquid on the bearing’s sliding part, and it is transferred to the pores when sliding.

Why use bronze bushings?

Bronze bushings are present in many alloys and are also strong, having durability and resistance against wear, corrosion and shock.

How do the performance of sleeve bearings (bushings) and ball bearings compare?

Sleeve bearings are low-cost and also need low maintenance. They can be installed easily in applications where the load is high, and speed is low, compared to ball bearings, which offer smooth operation.

Is a bushing a plain bearing?

Yes, bushing is a plain bearing which is used in an enclosure to create a bearing surface for rotating components.