The friction factor of bearing is affected by many factors，These factors can be summarized in the following aspects：

one、Material property

1. Material selection：Hardness of bearing material、Surface roughness、The structure of the structure and the formation of the lubricating film will directly affect the friction factor。Shear strength of different materials、Abrasion resistance、Lubrication performance and other characteristics are different，This results in a difference in friction factor。

2. Surface property：Due to pollution、Chemical heat treatment、The role of plating and lubricants，The metal surface may form an extremely thin surface film（Such as oxide film、Vulcanized film）。The properties of this film affect the actual contact area and the shear strength between the friction pairs，Which affects the friction factor。The surface film is too thin and may be easily crushed，Resulting in direct contact with the base material；However, if the surface film is too thick, the actual contact area may be increased due to the softer film，Or create a furrow effect，All of this changes the friction factor。

two、Bearing design

1. Structural design：Structural design of bearings、Size and shape also affect the friction factor。Reasonable structural design can reduce unnecessary friction and wear，Improve the transmission efficiency and service life of bearings。

2. Matching material：The friction factor of the metal friction pair varies with the nature of the matching material。The same metal or more miscible metal friction pairs are prone to adhesion，Its friction factor is large；conversely，Low friction factor。Materials with different structures have different friction characteristics，For example, graphite has a stable layered structure and the binding force between layers is small，Easy to slide，Therefore, the friction factor is small。

three、Lubrication condition

1. Lubrication mode：Bearing lubrication conditions include oil film lubrication、Interference lubrication and edge lubrication, etc。The friction factor will be different under different lubrication methods。Good lubrication can reduce direct contact between friction pairs，This reduces friction factor and wear。

2. Lubricant properties：Type of lubricant、viscosity、Properties such as temperature stability also affect the friction factor。Choosing the right lubricant for reducing friction factor、It is very important to improve bearing performance。

four、Working environment

1. temperature：The influence of the temperature of the surrounding medium on the friction factor is mainly caused by the change of the property of the surface material。Such as，The friction coefficient of many metals and their compounds will appear to be minimum over a specific temperature range。In addition，High polymer friction pair or pressure processing，The friction factor will have a maximum value with the change of temperature。

2. Humidity and pollutants：Humidity and pollutants in the working environment will also affect the friction factor of the bearing。Excessive humidity may cause lubricant failure or corrosion；Contaminants may enter the bearing，Broken lubricating film，Increase friction and wear。

five、Load and speed

1. load：The load of the bearing also affects the friction factor。Generally speaking，The friction coefficient of metal friction pair decreases with the increase of load，And then it tends to stabilize。This is because the actual contact area increases as the load increases，But it will also make the lubrication film easier to form and maintain。

2. Rotational speed：The influence of rotational speed on friction factor is mainly reflected in the influence of surface heat and temperature rise。The sliding speed will cause the surface heat and temperature rise，Changing the properties of the surface，Which in turn affects the friction factor。

To sum up，The friction factor of a bearing depends on the material properties、Bearing design、Lubrication condition、The combined influence of many factors such as the working environment and load and speed。In practical application，It is necessary to select the appropriate bearing material according to the specific working conditions、Lubrication mode and working environment parameters，To reduce the friction factor、Improve bearing performance and service life。