How many types are there for the rotating ring of a mechanical seal? What are their respective features?
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This post was last edited by Zunming Machinery on 2023-12-7 at 11:15. Dynamic loops can be divided into non-compensated and compensated types. In static mechanical seals, a non-compensating rotating ring is used; this ring is fixed to the shaft (Figure 17), or in some cases it is pressed against the shaft by a sleeve (Figure 3). Clearly, such rotating rings cannot float. Compensating dynamic rings are widely used in rotary mechanical seals. When the sealing end face is worn, the moving ring automatically compensates under elastic force; the sealing between the moving ring and the shaft sleeve is achieved through an auxiliary seal ring. Currently, there are significant structural differences among dynamic rings. Based on the sealing methods used between the dynamic ring and the shaft sleeve, they can be classified into three main categories: dynamic rings with auxiliary sealing rings installed axially, dynamic rings with auxiliary sealing rings installed radially, and dynamic rings equipped with bellows. The moving ring, which is mounted axially by means of an auxiliary sealing ring (Figure 18), achieves sealing by pressing the sealing ring with spring force. The spring force can be considered constant; it offers reliable sealing, a long service life, and is easy to install, which leads to its widespread use. The moving ring with radially mounted auxiliary sealing rings (Figure 19) achieves sealing through the interference and elasticity of the sealing rings; its materials are mostly polytetrafluoroethylene and synthetic rubber. As time of use increases, these two materials undergo cold flow deformation and aging, respectively, resulting in the loss of their elasticity. According to literature, 40% of the failures in the sealing of this type of structure occur at the auxiliary seal ring. The third type of moving ring refers to the bellows-type seal, in which the moving ring and the bellows are made into one unit (Figure 8); therefore, a moving ring seal ring is not required.
The rotating ring is a key component in mechanical seals, used to prevent liquid leakage. There are mainly the following types along with their characteristics: 1. Non-compensating rotating ring: This type of rotating ring is usually fixed to the shaft or shaft sleeve and cannot adjust itself. Since the rotating ring cannot float, they are generally used in static mechanical seals and are not suitable for sealing applications with axial displacement. When using this type of moving ring, it is necessary to ensure the stability of the mechanical equipment’s operation and reduce axial vibrations, in order to prevent excessive wear of the sealing surfaces. 2. Compensating dynamic ring: The compensating dynamic ring is primarily used in rotary mechanical seals; it can automatically adjust its axial position and provide compensation in response to wear on the sealing surfaces. It relies on the force of springs or other elastic elements to maintain a sealed contact with the stationary ring. This type of moving ring is characterized by its strong adaptability, enabling it to compensate for axial movement of the shaft, thermal expansion, or other causes of dimensional changes. Based on the sealing method between the moving ring and the shaft sleeve, compensatory moving rings can be further divided into the following three categories: – Moving rings with axially installed auxiliary seals: In these types of moving rings, the auxiliary seals are installed along the axial direction, which allows them to adapt well to the axial movement of the shaft. - Moving ring with radially installed auxiliary seal ring: In this type of moving ring, the auxiliary seal ring is installed along the radial direction, and it is suitable for applications that require special sealing capabilities, such as pipeline sealing. - Moving ring with bellows: This type of moving ring achieves sealing through a bellows, which also functions as a spring and can compensate for wear on the sealing surface as well as axial movement of the shaft. This design eliminates the risk of springs failing due to medium corrosion or blockage, making it suitable for sealing applications in harsh chemical environments. When selecting the type of moving ring, it is necessary to determine the appropriate type based on the actual working conditions and the operating characteristics of the equipment. .