Technicality
ROTARY JOINT
What is a Rotating Joint?
ROTOTECH rotating joints are used to transfer steam, water, hot oil, hydraulics, air, etc. from stationary supply lines to rotating machine parts such as shafts, drums or rolls.
 
In textile, rotating joints are used to heat or cool drums/rolls without energy lose.
In paper sector; rolls which used to dry the wet paper, must be heated. To heat these rolls; hot oil or steam is used. While rolls rotate, supply and return lines are stationary. Rotating joints are used to connect these stationary pipes to rotating rolls without any leakage.

Another example may be iron & steel industry. In continuous casting process hot steel is cooled with rolls. These rolls are cooled from inside and outside. Demineralized water is used to cool these rolls from inside. While hot steel passes, these rolls rotate and rotating joints are used to transfer water from stationary supply lines to rotating rolls.

Design of Rotating Joints:

While rotating joint design, configuration and applications are changed, they have four basic components; housing, shaft, bearings and seals.
The most important component of the rotating joint is the seal. Seal prevents the medium to leak from the joint. Rotating joints has one static seal (o-ring or lip seal) and one dynamic seal (mechanical seal).
Second most important component of the rotating joint is the bearing. Rotating joint may have one or multiple bearings. There are two types of bearings; 1) Roller bearings (which has rolling components inside like ball bearings); 2) Non-roller bearings (which doesn't have rolling components inside, like carbon graphite or bronze bearings)

Shaft is the component that allows the medium to flow inside the joint to the drum or roll. In most cases shaft will rotate with the roll. In some cases where the size of the rotating joint is bigger, shaft will be stationary and the housing will rotate with the roll.

Housing is the component that holds all internal parts together. The housing has an inlet port (threaded or flanged) where inlet hose is assembled. If the rotating joint is dual flow, housing will also has a second port to remove the medium from the roll.
In small rotating joints, the housing is stationary and shaft rotates with the roll. And in larger models, the housing is assembled to the drum with flange and bolts and so that housing will rotate with the drum.

When choosing the right product, pay attention to

• Application parameters
• Temperature of the surroundings
• Medium pressure
• Spare parts and warranty
• Consultancy

Please bear in mind that all factories have different application parameters and wrong product selections will cause bigger problems that increases the maintenance costs.