The Main Differences Between Cap-Type and Through-Hole Conductive Slip Rings
Conductive slip rings come in a wide variety of types, distinguished either by their specific application or by their physical form factor. For instance, a "through-hole" conductive slip ring features a hollow shaft running through its center—hence it is also commonly referred to as a "hollow-shaft" slip ring. Conversely, a "capsule" (or "cap-type") conductive slip ring is so named because its exterior shape resembles a cap or capsule.
We will now provide a detailed comparison and analysis of the distinctions between capsule-type and through-hole conductive slip rings. In terms of rated current, the maximum current per ring in a capsule-type slip ring is typically limited to around 2 amperes. Exceeding this limit risks compromising insulation integrity (dielectric breakdown) and increases the likelihood of electromagnetic interference between adjacent rings, thereby degrading signal transmission quality and potentially causing signal distortion or data corruption. In practical applications, capsule-type slip rings are primarily utilized in compact, precision devices—such as high-speed dome cameras and high-definition (HD) equipment—where the required maximum and rated current loads are relatively low. Furthermore, because capsule-type slip rings are manufactured via standardized, mass-production processes, they offer low manufacturing costs and are sold at a relatively affordable price point. However, capsule-type conductive slip rings face significant limitations regarding environmental protection, such as water and dust resistance. Generally speaking, they are unsuitable for use in environments with high relative humidity (RH); moreover, they cannot be deployed in specialized settings that require explosion-proof or dust-proof capabilities.
In contrast, only a small fraction of through-hole conductive slip rings are standard off-the-shelf products; the vast majority belong to custom-engineered series. Through-hole slip rings can be designed to accommodate a wide array of specific requirements and unique specifications requested by clients. Consequently, both the manufacturing costs and the selling prices of through-hole slip rings are significantly higher than those of their capsule-type counterparts. Additionally, since the housing of a through-hole conductive slip ring is typically constructed from aluminum alloy, it exhibits superior resistance to aging, cracking, and deformation, making it a highly advantageous choice for deployment in a wide range of harsh and demanding environments.
