The conductive slip ring can be roughly divided into brush slip ring, carbon brush slip ring, fluid slip ring, etc. according to the rotating conductive medium. The brush conductive slip ring uses precious metal brush wire as the contact material for rotating conduction. The brush conductive slip ring has a series of advantages, such as good conductivity, good sealing, and high service life. As the original conductive slip ring, carbon brush conductive slip ring has been widely used in various fields, but there are two fatal weaknesses of carbon brush conductive slip ring that cannot be solved (1. Carbon brush is easy to wear, and its service life cannot be guaranteed. 2. Rotating friction is easy to generate high temperature, and its safety cannot be guaranteed). The advantage of carbon brush slip ring is that it has a mature production process, and its price is very cheap. Fluid conductive slip ring is made of liquid metal as the material of rotary conduction, and the most mature one is a mercury slip ring.
**** but Why are high-end mercury slip rings not widely used?
Mercury conductive slip rings originated in Taiwan first. Mercury conductive slip rings make use of the conductivity of mercury and the characteristics of fluid. The researchers sealed the mercury in a narrow space and conducted electricity by using the copper column to contact the mercury, so as to avoid the highly toxic and evaporative properties of mercury. Compared with brush conductive slip ring, mercury slip ring has a series of advantages such as small resistance, small rotation torque, etc. But why is the mercury conductive slip ring not widely used?
In fact, this has a lot to do with the nature of mercury itself. Mercury is a volatile and highly toxic metal, which has a great potential safety hazard in the production process. Moreover, under the premise of domestic environmental protection, mercury slip rings are destined not to be produced on a large scale. In addition, mercury itself is not cheap, which leads to the high price of mercury slip rings, which will lead to an increase in the cost of use. In fact, many manufacturers of conductive slip rings, slip rings, disc type slip rings and optical fiber conductive slip rings also affect the wide application of mercury conductive slip rings
