The main differences between SF-1 oil-free lubrication bearings and SF-2 boundary lubrication bearings

SF-1 bearing (oil-free lubricated bearing)

There are significant differences between SF-1 bearings (oil-free bearings) and SF-2 bearings (boundary lubrication bearings) in many aspects:
Lubricating properties:

• SF-1 bearings are suitable for places where refueling is impossible or difficult to refuel. They are designed with no oil lubrication or less oil lubrication, so they can be used with little or no maintenance.
• SF-2 bearings can make full use of trace amounts of grease and can be maintained without refueling for a long time under boundary lubrication conditions. However, under completely oil-free lubrication conditions, its friction performance and allowable PV value are low, so oil storage pits are usually rolled out on the plastic surface and lithium-based grease or silicone grease is applied during assembly.
  Wear resistance:
• SF-1 bearings have good wear resistance, small friction coefficient and long service life.
• The wear resistance of SF-2 bearings is also good, but the "run-in" wear rate under grease lubrication conditions is very small. When the grease applied during assembly is consumed to a certain extent, the wear rate gradually increases. If the oil is refueled before the wear rate rises, the wear rate remains stable.
  Carrying capacity:
• SF-1 bearings have a moderate amount of elastoplasticity, which can distribute stress over a wider contact surface and improve the bearing capacity.
• SF-2 bearings have good load-bearing capacity and are suitable for rotational motion, rocking motion under high load and low speed, and situations where frequent opening and closing under load make it difficult to form hydrodynamic lubrication.
  Structure and materials:
• SF-1 bearing adopts thin-walled structure and light weight, which can reduce the mechanical volume. The back of the steel can be electroplated with a variety of metals and can be used in corrosive media.
• The plastic layer on the surface of the SF-2 bearing can leave a certain margin during processing and molding. After assembly and pressing into the seat hole, it can be processed by itself to achieve better assembly dimensions. Its surface polymer is resistant to chemical corrosion, and its corrosion resistance mainly depends on the steel back and surface electroplating layer.
  Exterior:
• The inner layer of SF-1 bearing is a gray wear-resistant layer that is smooth to the touch.
• The inner layer of the SF-2 bearing has pit-shaped oil storage pits.
  To sum up, there are significant differences between SF-1 bearings and SF-2 bearings in terms of lubrication characteristics, wear resistance, load-bearing capacity, structure and materials, and appearance. Which bearing to choose depends on the specific application scenario and needs.

SF-2 bearings (boundary lubricated bearings)