A bimetal bearing is a plain bearing that uses two different metals layered together to form one bearing surface. The two metals are bonded together using an intermediary metal or alloy, which allows for relative movement between the two layers. Bimetal bearings offer many benefits over traditional single-metal bearings, including increased load capacity, higher speed capabilities, and improved wear resistance.
Bimetal bearings are commonly used in applications where there is a need for high load capacity and high speed, such as in automotive and aerospace applications. However, bimetal bearings can also be found in other industries, including mining, construction, and food processing. Bearings and bushes suppliers offer various bimetal bearings for different applications.
In this post, we will take a closer look at bimetal bearings, their construction, and their advantages over traditional single-metal bearings.
What is Bimetal Bearings?
Bimetal bearings are high-quality bearings. They feature a low-carbon steel foundation and a bronze alloy surface coating.
After obtaining the proper material, the bimetal bearings are subjected to high temperatures. The bimetal bearings are then sintered and wound with copper and steel bimetallic strip coils.
The rolled strip is suited for various uses, such as bushes and thrust washers, and can withstand the medium-high speed and high impact forces.
The bimetal bearings are suited for moderate usage and significantly impact load under a bush or thrust washers.
Application of Bimetal Bearings
Bimetal bearings are found in a wide range of applications. The most common applications for bimetal bearings are:
- Agricultural equipment
- Construction equipment
- Food processing equipment
- Mining equipment
- Pumps
- For heavy-duty truck applications, such as the engines, transmissions, and axles
- After-treatments for automobile exhausts
- Trucks that carry logs
- Hydraulic cylinders
- Lifting applications
- Medical devices
- Valves for natural gas pipelines
Material Used in Bimetal Bearings
Usually, bronze and copper are used to layer the bimetal bushes. A bronze sliding layer commonly encircles a two-layered bimetal bearing. You may combine the bimetal bearings and bushings with stainless steel, carbon steel, or bronze.
Bimetal bearings are composed of carbon steel that has been melted and formed into a shape, then coated with copper or tin plating on the outside.
Customers can also select high tin aluminum alloy for layers or any other copper layer material they choose.
The inner wall copper layer is most frequently made of CuSn6Zn6Pb3 or CusN6.5P0.1 (i.e., two kinds of tin bronze and two sorts of lead bronze).
Bimetal bearings can be manufactured utilizing four distinct types of copper and lead/bronze alloys.
CuPb24Sn4 (Copper, Lead, and Tin)
- It is resistant to wear, corrosion, and fatigue.
- Due to the high lead range in the alloy and its high density, it is vulnerable to lead segregation, which reduces the bushing's abrasion resistance.
- The heat-treating process may also weaken the steel layer and steel back.
- The high-cost copper layer is utilized in high-speed, swing, and rotating wages when the bearing is under stress.
CuPb10Sn10
- It has adequate lubrication ability, wears resistance, and corrosion resistance.
- It's more durable than polyurethane and has a heavier impact on load-bearing. It's also more suited for medium to higher speeds.
- The gasket's surface pressure is too high.
- There is also the pressure of the sliding bearing, such as a bimetallic bearing shell or piston pin set, lining, and so on.
CuSn6Zn6Pb3 (Copper, Tin, Zinc, and Lead)
The steel component of this material enables the bearing to function under general load and moderate sliding speed, such as turbines, motors, compressors, piston clutches, connecting rod bushings, rocker arm bushings, and so on.
Cusn6.5-0.1 (copper and Tin):
The bimetallic bearings are in use in the following applications:
- Balance axle bushing
- Gasket
- Spindle bushing of a gasoline or diesel engine
- Removing and installing the connecting rod bushing
- Rocker arm bushing
- Friction plate on the oil pump side
- Medium and small-capacity gasoline engine bushing
Furthermore, aluminum alloys are corrosion-resistant, have good sliding performance, moderate fatigue strength, and adequate bearing capacity.
It's a general-purpose, low-cost grease that can be used with soft shafts and is commonly utilized in engines of all sizes, railway engines, air compressor bearing sleeves, and other industries. It's the finest option for babbitt metal.
Advantages of Bimetal Bearings
There are many advantages of bimetal bearings, some of which are listed below:
- Bimetal bearings are highly durable.
- Generally, they perform best in medium-speed, medium-load, low-speed, and high-load environments.
- The friction surface can be used to process various oil grooves, pockets, and holes using distinct processes to suit a variety of lubrication situations.
- The bearings have good antifriction properties and can sometimes be used without lubrication.
- The bimetal bushing has a self-lubricating function and can work without maintenance for a long time.
- The bimetal bushing has a low friction coefficient, which can save energy.
- The bimetal bushing has a long service life and is not easy to produce noise.
- Bimetal bearings have good impact resistance and load-bearing capacity.
- The bimetal bushing has good corrosion resistance and can work in a corrosive environment.
What Size Do Bimetal Bearings Come In?
Bimetal bearings are manufactured by bearing manufacturers in various sizes and materials, including metal, plastic composites, and a mix. Some applications demand big bearings, while others require little bushings.
Bushings are typically less than a few inches long; the normal size is 0.8 to 2-4 inches.
Types of Bimetal Bearings
There are three main types of bimetal bearings:
Flange bushes:
- Flange bushings, commonly known as flange bearings, are sintered bronze, oil-impregnated load-bearing bushings.
- Flange bushings are used at lower speeds and under lighter stresses because the mating shaft can still spin freely within the bushing.
- Flange bearings are equal to cylindrical sleeve bearings in that they include a flanged end that serves as a load-bearing surface for axial forces.
- They're used in various industries and applications, including agriculture, aerospace, automobile manufacturing, appliances, machine tools, and hydraulics.
- It does not need to be oiled regularly.
Thrust Washers
- Thrust washers are flat washers that sit between a revolving component and a fixed element.
- They support the axial strain or side-to-side motion and restrict movement along a shaft.
- The bearing is supported by the thrust washer, which acts as a support surface.
- Every application, unless it's highly specialized, requires the use of a wear surface.
- Material choice is determined by various factors, such as speed, weight, and temperature.
- Thrust washers are made from various materials, including plastic, brass, bronze, stainless steel, graphite, and other metals. The majority of thrust washers are manufactured of low- or high-carbon steel.
- Case hardening or total hardening is possible with carbon steel.
Strip Bushings
- Electrical cable preparation requires accurate cuts, accomplished via a combination of strip bushings and adapters. Bushings and adapters are a preferable alternative to blades in this situation.
- Clean and safely prepare electrical cables with these stripping bushings.
- They might assist you in achieving precise cuts and are a safer alternative to blades.
The Function of Bimetal Bearings
The three primary purposes of bimetal bearings are as follows.
- To decrease friction
- Carry loads
- Position Elements
Read here to know a quick guide to choosing plain linear bearings.
In Conclusion
Bimetal bearings are an essential part of the machinery and have many advantages over other types. They are available in different sizes and materials to suit the needs of different applications.
Bimetal bearings have a high level of wear resistance and can be used without lubrication for a long time. They also have good antifriction properties and can save energy. Bearing manufacturing companies can produce bimetal bearings in various sizes and materials to suit the needs of different applications.
