Sleeve bearings, also known as bushings, plain bearings, or journal bearings, are used to carry linear or rotational motion between two parts. Sleeve bearings have a sliding action, unlike the rolling action of ball or roller bearings. They can be used with lubricants or self-lubricating parts when needed to ensure smooth and continuous operation.

Lubricated sleeve bearings provide low friction coefficients and excellent wear resistance. And because they are relatively low cost and maintenance-free, sleeve bearings are used in many applications.

What is the difference between sleeve bearings and bushings?

Sleeve bearings are bushings, just with different names, while bushings are tubes or sleeves that allow linear or rotational motion, which is what sleeve bearings are. These terms can be used interchangeably.

Sleeve bearings, plain bearings, journal bearings, and plain bearings are all called bushings; these names describe the style of the bushing. Simply put, a bushing is a bearing, but not all bearings are bushings.

What is the purpose of a sleeve bearing?

Sleeve bearings facilitate motion between two parts, reduce friction, and absorb vibration. They have a high load capacity and are suitable for a range of heavy-duty applications.

Robust sleeve bearings can withstand high loads and temperatures with very low wear. Their contact area has a high resistance to shock loads and can compensate for misalignment of other components.

They offer many advantages; low friction, compactness, reduced system size, light weight, easy installation and help eliminate vibration (and therefore noise).

Where are sleeve bearings used?

Sleeve bearings are very versatile and can be used in a wide range of applications. They can be used to facilitate motion in different groups:

Rotary motion

Linear motion

High-frequency oscillatory motion

They are commonly found at pivot points and are therefore widely used in the automotive industry, manufacturing machinery and white goods. In the automotive industry, they provide rotary linear motion for hinges, seat adjustment mechanisms and steering forks. Belt tensioners use sleeve bearings for high-frequency oscillatory motion. They are needed to facilitate linear motion when manufacturing lift and tilt equipment, another example is U-joints for hydraulic cylinder pins.

Types of sleeve bearing designs and materials

There are several basic types of sleeve bearings and a range of materials to choose from. All sleeve bearings are a one-piece design, with the most common type being the flanged sleeve bearing. Flanged sleeve bearings can accommodate both axial and radial loads. Alternatives include cylindrical and thrust washer designs. For higher side loads, a combination of thrust washers and cylindrical bearings is a good option. If the load is purely radial, choose a simple cylindrical bearing.

Bearings can be made from a variety of materials. These include metals, bimetals, ceramics, stone, graphite, composites, and plastics. The function of a sleeve bearing depends on the material selection, as the material will determine strength, elasticity, coefficient of friction, etc.

Cast or sintered metal bushings have a low coefficient of friction under fluid dynamic conditions when used with hardened steel shafts, but are not suitable for some applications due to their high noise levels. Molded plastics are a low-cost option available in a variety of shapes and sizes; however, plastic bearings have limitations.

SF-1 bearings are made from a high-performance plastic (PTFE) that is metal reinforced and self-lubricating. PTFE dampens sound and vibration, unlike all-metal bearings, which can generate high noise levels. For sleeve bearings to be self-lubricating, a composite layer needs to be added. This ensures smooth operation and extends the service life of the sleeve. External lubricants are sometimes beneficial in terms of wear and friction. Here, additional grooves within the surface can be used as lubricant storage.

SF-1 bearings do not require external lubricants such as grease or oil. This means they can operate reliably in robust operating conditions and over a range of operating temperatures.

There are many benefits to using SF-1 sleeve bearings. The unique material structure and combination enables our engineers to select the best material for a specific application. Other aspects can also be fine-tuned: thick PTFE sliding layers for misalignment compensation, consistent friction coefficients and reduced NVH. Choosing metal as the backing material provides high load capacity and can be optimized for corrosion resistance if required. We can adjust the conductivity of the bearing sliding material by selecting the right filler and can go with a thin-walled design if space is an issue.

If you require a consultation or custom bearing, please contact us.