1. Temperature

The operating temperature range of the floating oil seal is related to the material of the rubber ring. Please refer to the table. However, the effects of lubricating oil viscosity, environmental corrosion, friction heat caused by high linear speed, etc. must also be considered.

2. Pressure

The maximum operating pressure requirement of the floating oil seal is less than 0.345MPa. A higher internal and external pressure difference will increase the contact specific pressure of the sealing surface of the floating seal ring. When continuous operation is required, the operating pressure cannot exceed 0.24MPa.

3.Linear speed

(1) The contact specific pressure that enables the floating oil seal sealing surface to fit well is related to the linear speed of the floating oil seal, and its relationship can be represented by a diagram. There are many factors that affect this relationship, such as: floating ring material, floating seal ring diameter, operating temperature, lubricating oil viscosity, restoring force generated after the rubber ring is compressed and deformed, etc. Under conditions of low speed, light lubricating oil, when the internal and external pressure difference is large, and the axial gap or swing is large, the contact specific pressure of the sealing surface is usually increased to ensure the reliability of the seal. Under high-speed conditions, the lubricating oil will be thrown away from the sealing surface under the action of centrifugal force, causing the sealing surface to lack lubrication. Moreover, the centrifugal force will raise and roll up the sealing surface of the floating seal ring, increasing the angle of the back cone surface, causing the sealing surface to contact the specific pressure. increase. Both of these reasons can easily cause the sealing surface to burn out. Therefore, under conditions of high linear speed or high ambient temperature, it is usually chosen to reduce the sealing surface contact specific pressure. The maximum linear speed of the floating oil seal is generally required not to exceed 1m/s for the floating seal ring of bearing steel and not to exceed 3 m/s for the cast floating seal ring, and varies depending on the material of the floating seal ring. There are also examples of successful use at 7.5 m/s. When continuous operation is required, it is recommended that the linear speed does not exceed
1.8m/s. When the sealing medium is grease, the maximum linear speed of the floating oil seal cannot exceed 0.5m/s.

(2) The installation clearance A required for most designs of type A floating oil seals is 3±0.5mm. The installation gap size can determine the position of the floating seal ring and the compression amount of the O-ring, making it strong and dry. When the linear speed is greater than 4m/s, in order to reduce the contact specific pressure of the sealing surface of the floating seal ring, the installation gap dimension A can be increased by referring to the figure. This picture is set based on the standard design hardness of O-ring ShoreA60. If the design hardness of O-ring is larger than ShoreA60, further measurement is required.