What the slip ring has to handle
- Signal circuits for fill level, temperature and pressure sensors
- Ethernet or fieldbus for valve and sensor networks, shielded from motor cables
- Stainless steel construction and seals compatible with washdown, CIP and SIP
- High IP rating on housings and connectors
- Combined gas or air rotary union passages
- Long life and easy replacement to limit line stoppages
Typical figures
| Rotary union | Example bottle-packaging union: 6 gas passages, up to 7 bar, up to 10 rpm, stainless steel |
|---|---|
| Ingress protection | IP68 receptacles on example integrated electrical slip ring |
Example figures from the published sources listed below. Your requirement may differ; an engineer will confirm against your duty cycle.
Recommended slip ring types
Standards to consider
- EN 1672-2 - hygiene requirements for food processing machinery
- EHEDG guidelines - hygienic equipment design
- IEC 60529 - IP code for washdown enclosures
- IEC 60204-1 - electrical equipment of machines
The complete system
A slip ring rarely works alone. For bottling & filling machines it is usually specified together with:
- carousel drive motor
- servo drive
- encoder
- valve manifold
- rotary union
Specifying these together avoids mismatched connectors, cable routes and feedback interfaces, and gives you one point of contact for the whole axis.
Common problems to design out
- Water and chemical ingress during washdown
- Seal failure causing contamination
- Signal loss from worn contacts
- Unplanned downtime when replacing a failed ring
Frequently asked questions
Why does a rotary filler need a slip ring?
Sensors on the rotating bowl monitor fill level, temperature and pressure, and those signals must reach the stationary controller. A slip ring, or a wireless alternative, bridges that gap.
What materials suit washdown slip rings?
Stainless steel housings and seals compatible with CIP and SIP chemicals are typical, with high-IP connectors. One stainless rotary union for bottle packaging combines gas passages with an IP68-rated electrical slip ring.
Are wireless sensors an alternative to filler slip rings?
For low-bandwidth sensor signals, battery-powered wireless nodes can replace slip rings and remove wear parts. Power to motors or valves on the carousel still needs a slip ring.