Open and frameless slip rings
Moog Fiber brush separates open and frameless slip ring
Unhoused ring and brush-block sets using fibre brush contacts for integration into customer structures.
Need this part, a replacement or a better-fit option? Our engineers help with selection, procurement, sourcing, competitive pricing and lead times.
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Need Moog parts, a replacement or another suitable option? Send your part number or describe the application. We’ll review the requirement and help with product selection, sourcing, pricing and lead times.
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- 4Volumes
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Key specifications
| Current per circuit (max) | 50 A |
|---|---|
| Bore | 45.7–101.6 mm |
Summarised in our own words from Moog Inc.'s published data; series maxima, individual models vary. Last checked 2026-10-29. Source 1
Notes on this data
Dimensions converted from published inches. Bores 1.8 in (2 A), 2.8 in (5-50 A), 4.0 in (10-50 A).
Specify Motion is not affiliated with Moog Inc.. Moog and Fiber brush separates are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Moog Fiber brush separates replacement and alternative options
Use these supply-network options as a starting point for an engineering check. We can also help source the original Moog part. Published series figures do not establish an exact-model or drop-in replacement: confirm ratings, fit, interfaces and approvals for your application.
Flameproof (Ex d IIB T4 Gb) slip rings for gas hazardous areas, Zones 1 and 2, in oil, gas and chemical plant.
| Published maximum | Fiber brush separates | Explosion-proof Slip Ring (ER-EX) |
|---|---|---|
| Circuits | — | 17 |
| Current per circuit | 50 A | 100 A meets or exceeds |
| Speed | — | 50 rpm |
| Bore | 101.6 mm | 180 mm meets or exceeds |
Large through-hole slip rings for heavy outdoor plant, with through holes quoted up to 1000 mm and long service life.
| Published maximum | Fiber brush separates | Large Size Slip Ring |
|---|---|---|
| Circuits | — | 35 |
| Current per circuit | 50 A | 50 A meets or exceeds |
| Voltage | — | 500 V |
| Bore | 101.6 mm | 1,000 mm meets or exceeds |
Electrical slip rings with up to five built-in RF channels for radar and satellite antennas, grouped in the catalogue with cable-reel slip rings for cranes and masts.
| Published maximum | Fiber brush separates | RF Integrated Electrical Slip Ring / C… |
|---|---|---|
| Current per circuit | 50 A | 50 A meets or exceeds |
| Speed | — | 300 rpm |
| Bore | 101.6 mm | 275 mm meets or exceeds |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
Typical applications
What an open and frameless slip ring is
An open or frameless slip ring is supplied as separate components, typically a ring assembly and one or more brush blocks, without its own housing or bearings. The machine builder mounts the rings on the rotating part and the brushes on the stationary frame, using the machine's own bearings to locate them. This lets the slip ring fit around large shafts, inside existing housings or in very short axial spaces. Designs range from precious-metal signal rings to heavy copper rings with carbon brushes for high current.
When engineers choose an open and frameless slip ring
Choose a frameless design when a housed unit will not fit, when the bore is very large or when the machine already has stiff bearings and a protected space to house the rings. It saves weight and length and avoids a second set of bearings fighting the machine's. The trade-offs are responsibility and risk: concentricity, runout, brush preload, sealing and contamination control all move to the machine builder. Plan assembly, setting and inspection procedures carefully.
How to specify the Moog Fiber brush separates
Send these with your enquiry and an engineer can confirm the right Fiber brush separates variant or an equivalent:
- Ring inner and outer diameter and stack length (mm)
- Permitted runout and axial float of the machine (mm)
- Number of circuits, current and voltage (A, V)
- Brush type and number of brushes per ring
- Speed (rpm) and expected life
- Environment inside the machine: dust, oil, humidity
- How the brush block is located and adjusted
Common mistakes to avoid
- Leaving runout and concentricity tolerances undefined between ring and brush block
- Installing rings where oil mist or swarf can reach the contacts
- Not designing an anti-rotation method for the ring assembly on its shaft
- Omitting an assembly and setting procedure for the brush preload
Moog Fiber brush separates: frequently asked questions
Can you help replace Moog Fiber brush separates or source the original?
Send the full model code, quantity and required date. Our engineers can check original-part availability and assess suitable alternatives, including Motion Control Products options where appropriate. We confirm compatibility and any changes needed before recommending a replacement.
What is the Moog Fiber brush separates?
Unhoused ring and brush-block sets using fibre brush contacts for integration into customer structures. Published series figures include current per circuit 50 A, bore 45.7 mm, bore 101.6 mm. It is made by Moog Inc.; Specify Motion can help source it or propose an equivalent.
Who makes the Moog Fiber brush separates?
The Moog Fiber brush separates is made by Moog (Moog Inc.) and is listed here for engineers comparing options. Specify Motion is not affiliated with Moog Inc.; brand names are used only to identify the product.
What is the current per circuit of the Moog Fiber brush separates?
The published series maximum current per circuit is 50 A. Individual models and sizes in the Fiber brush separates range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the Moog Fiber brush separates?
We can assess suitable replacement options. On published figures, Motion Control Products Explosion-proof Slip Ring (ER-EX) and Motion Control Products Large Size Slip Ring are options to assess from our supply network. An engineer confirms the fit against your application before recommending anything.
What is the advantage of a frameless slip ring?
A frameless slip ring removes the housing and bearings, so it is lighter, shorter and can fit large bores or tight spaces inside an existing machine. Using the machine's own bearings also avoids alignment conflicts between two bearing sets. The machine builder takes on responsibility for runout, sealing and brush setting, so it suits teams that can control those tolerances.
How accurately must a frameless slip ring be installed?
The ring and brush block must stay concentric and within the runout and axial float the supplier specifies, typically a fraction of a millimetre, so brush pressure stays even around the turn. The rings also need protecting from contamination. Ask for an installation drawing with tolerances and a setting procedure, and allow for inspection access.
Further reading: How to select a slip ring · How to specify a slip ring · Slip rings
Other open and frameless slip rings series
Engineer support
Let our experienced engineers do the hard work for you
Tell us how you use the Moog Fiber brush separates: the load, speed, duty and environment. Our engineers will confirm whether it is still the right part, find it for you, or propose an alternative that fits better.
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