Company profile
Rotary Systems
Rotary Systems Inc. is a US maker of rotary unions, slip rings and combined slip ring unions, based in Ramsey, Minnesota and certified to ISO 9001:2015. Its slip rings run from 2 A capsules to a 30 A, 600 V industrial ring and a PoE-capable gigabit Ethernet capsule. Contact: +1 763 323 1514, info@rotarysystems.com.
| Legal name | Rotary Systems Inc. |
|---|---|
| Owner / parent | Rotary Systems Inc. |
| Headquarters | Ramsey, MN 55303, United States |
| Website | rotarysystems.com |
Rotary Systems contact details
Head office and factory
14440 Azurite Street NWRamsey, MN 55303
United States
Telephone +1 763 323 1514
Email info@rotarysystems.com
Website rotarysystems.com
Contact details as published by Rotary Systems Inc., checked 2026-10-30. Specify Motion is not affiliated with Rotary Systems Inc..
Rotary Systems product lines
| Rotary unions | Single and multiple passage, mechanical-seal and hydrostatic unions, timing valves |
|---|---|
| Capsule slip rings | Gold-contact capsules up to 750 rpm, plus through-bore capsules up to 600 V AC |
| Sealed slip rings | IP65 rings rated up to 10 A at 600 V AC |
| Industrial slip rings | 30 A, 600 V AC covered ring for slow heavy equipment |
| Separates | Rotor and brush block for integration, bores up to 4.75 in |
| Slip ring unions | Combined fluid, power and signal rotary assemblies |
Who Rotary Systems is
Rotary Systems Inc. is a Minnesota manufacturer of rotating connections. Its core products are rotary unions, which carry fluids such as coolant, hydraulic oil and air across a rotating joint, and slip rings, which carry electrical power and signals. It also combines the two in slip ring unions. The company is certified to ISO 9001:2015 and marks its products as made in the USA.
For machine builders, Rotary Systems is useful when a rotating axis must pass both fluid and electrical services, because it designs both halves.
History and ownership
The About page says the company has worked with engineers for over two decades, that its staff have a combined 80 years of engineering experience, and that it has custom-built more than 700 unique rotating unions. Its 30,000 sq ft facility can machine parts up to 60 in (1.5 m) in diameter. The website does not name founders, owners or a founding year.
Product portfolio
Slip rings
Rotary Systems publishes current, voltage, speed and bore for each standard slip ring, though not circuit counts.
- The capsule slip rings (SR009, SR010) use gold contacts in anodised aluminium housings, rated 3 A at 150 V DC or 2 A at 250 V DC at up to 750 rpm.
- The through-bore capsules and sealed rings (SR013 to SR018) carry 5 to 10 A at 500 to 600 V AC through bores from 0.503 to 1.50 in (12.8 to 38.1 mm), at 250 to 600 rpm. SR017 and SR018 are sealed to IP65.
- The industrial slip ring SR004 is a covered IP65 ring rated 30 A at 600 V AC with threaded terminals, limited to 50 rpm.
- The separates are rotor and brush-block sets for building into a machine, rated 3 to 10 A at 150 to 210 V DC, with bores from 0.59 to 4.75 in (15 to 121 mm).
- The Ethernet capsule SR020 carries 10/100/1000Base-T Ethernet and PoE at up to 750 rpm.
Rotary unions and slip ring unions
The rotary unions and slip ring unions cover single- and multiple-passage designs, mechanical-seal and hydrostatic types, and timing valves. Combined slip ring unions let one assembly carry fluids, power and signals.
Technologies
Rotary Systems uses two contact metals: silver on higher-current separates and sealed rings, and gold on capsules and low-noise signal rings. Gold suits low-level signals and Ethernet, while silver suits power. Its hydrostatic unions use a fluid film rather than contacting seals, which reduces wear at speed.
For selection help, see how to select a slip ring, how to select a rotary union, capsule vs through-bore vs pancake slip rings and Ethernet through slip rings.
Industries served
The product range fits indexing tables, machine tools, packaging and process equipment, and slow heavy equipment such as mixers and cranes. Ethernet capsules suit robots and inspection systems that need networked devices on the rotating side.
Worked example: choosing between SR004 and a capsule
A slowly rotating mixer needs three-phase power at 20 A and 400 V AC, plus two sensor signals, at 10 rpm. The SR004 (30 A, 600 V AC, 50 rpm, IP65) covers the power circuits with margin. Low-level sensor signals are better carried on separate gold-contact rings, so ask whether a combined build is possible or use a second small capsule for the signals.
Things that catch engineers out
- Speed limits. The 30 A industrial ring is rated to just 50 rpm; high-current rings rarely suit fast axes.
- AC versus DC ratings. Separates are rated in V DC and through-bore rings in V AC; do not assume one rating carries over.
- Mixed services. Putting power and Ethernet in one ring needs shielding and spacing; specify both from the start.
Separates or a housed ring?
Separates (rotor plus brush block) cost less and fit inside your own enclosure, so they suit OEMs building many identical machines who can protect the ring themselves. Housed capsules and sealed rings arrive aligned and protected, which saves assembly time and suits lower volumes or dirty environments. With bores up to 4.75 in, the separates also clear large shafts that no standard capsule can.
Global and UK presence
Rotary Systems lists only its Minnesota facility and no UK office or distributors. UK engineers can contact the company directly. Allow for shipping time and check that connectors and cable standards suit UK and EU machines.
What to send when specifying a slip ring or union
Send the number of circuits, current and voltage per circuit, signal and data types, speed, bore or shaft size, environment and IP rating. For unions, add the media, pressure, flow rate and number of passages.
Specify Motion is independent of Rotary Systems and is not a distributor for the company. Our engineers can help source Rotary Systems products or propose equivalents from our supply network on published figures; see find a replacement or the slip rings hub.
Rotary Systems slip rings
Capsule slip rings (SR009, SR010)
Gold-contact capsule slip rings in anodised aluminium housings rated up to 3 A at 150 V DC (SR009) or 2 A at 250 V DC (SR010), at up to 750 rpm.
Through-bore capsules and sealed rings (SR013–SR018)
Through-bore slip rings rated 5 to 10 A at 500 to 600 V AC, with bores of 0.503 to 1.50 in (12.8 to 38.1 mm) and 250 to 600 rpm; SR017 and SR018 are sealed to IP65.
Industrial slip ring SR004
Covered industrial slip ring rated 30 A at 600 V AC with threaded terminals, IP65 enclosure and 50 rpm maximum for slow-turning heavy equipment.
Separates (SR001–SR012)
Separate rotor and brush-block slip rings for building into a machine, 3 to 10 A at 150 to 210 V DC, with silver or gold contacts and bores from 0.59 to 4.75 in (15 to 121 mm).
Ethernet capsule SR020
Capsule slip ring for 10/100/1000Base-T Ethernet, PoE capable, with gold contacts and low electrical noise at up to 750 rpm.
Rotary unions and slip ring unions
Single- and multiple-passage rotary unions (mechanical-seal and hydrostatic types, plus timing valves) and combined slip ring unions that pass fluid, power and signals through one rotating assembly.
Frequently asked questions
What is the Rotary Systems website?
Rotary Systems' official website is rotarysystems.com. It lists its rotary unions, slip rings, slip ring unions and custom solutions, with ratings for each standard slip ring, plus about, support, news and contact pages.
What is Rotary Systems' phone number and email?
Rotary Systems publishes +1 763 323 1514, a US toll-free number of 800 959 0146 and the email info@rotarysystems.com. Its About page also gives a fax number.
Where is Rotary Systems based?
Rotary Systems' About page gives 14440 Azurite Street NW, Ramsey, MN 55303, USA. The map link on the same page labels the location Anoka, Minnesota. Its factory covers 30,000 sq ft.
Who owns Rotary Systems?
The website names the company as Rotary Systems Inc. and does not describe its ownership, founders or any parent company. It says the business has worked with engineers for over two decades.
Does Rotary Systems have a UK distributor?
Rotary Systems lists no UK office or distributor on the pages we read; its products carry a 'Made in the USA' badge. Specify Motion is independent of Rotary Systems and can help source its products or propose equivalents.
What does Rotary Systems make?
Rotary Systems makes rotary unions (single and multiple passage, mechanical-seal and hydrostatic), timing valves, slip rings (capsule, sealed, industrial, separates and Ethernet) and slip ring unions that pass fluid, power and data through one rotating joint.
Sources
- Rotary Systems: home page
- Rotary Systems: about
- Rotary Systems: slip rings
- Rotary Systems: rotary unions
- Rotary Systems: slip ring unions
- Rotary Systems: contact
Figures are summarised from the sources above and from manufacturers' published data on the date shown. Always confirm against the current datasheet for your exact part.
Spec builder
Specify Rotary Systems parts or an equivalent
Select every part you need, answer the questions an applications engineer would ask, and see your summary before we ask for any details.
- 1Products
- 2Performance
- 3Environment
- 4Volumes
- 5Your spec
Engineer support
Ask about Rotary Systems parts or equivalents
Tell us what you need, whether it is this part, an equivalent or a complete axis built around it. An engineer will review your requirements and reply, normally within one working day.
- Reviewed by an engineer, not an autoresponder
- Like-for-like and better-fit alternatives
- Standard, modified and custom options
Prefer to configure it? Use the spec builder.
