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Through-bore slip rings

Moog AC6098 through-bore slip ring

Four-inch bore industrial slip ring offering up to 72 signal rings or power rings up to 50 A at 600 VAC.

Key specifications

Circuits (max)72
Current per circuit (max)50 A
Voltage (max)600 V
Speed (max)250 rpm
Bore101.6–101.6 mm
Outer diameter203.2–203.2 mm
Temperature-40–80 °C
Data / busEthernet

Summarised in our own words from Moog Inc.'s published data; series maxima, individual models vary. Last checked 2026-10-29. Source 1 · Source 2 · Source 3

Specify Motion is not affiliated with Moog Inc.. Moog and AC6098 are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.

Typical applications

Industrial machineryPackagingRoboticsIndex/rotary tables

Alternatives that meet or exceed these figures

Engineers often come to us with a Moog part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These series from our supply network is the closest match on published figures.

Through-bore slip rings

ER Series Through Bore Slip Ring

Meets or exceeds on 1 of 5 figures

Through-bore slip rings with a hollow centre so shafts, pipes or cables can pass through, carrying power, signal and fieldbus data. Standard bores run from 12.7 mm to 100 mm and custom bores are offered.

Published maximumAC6098ER Series Through Bore Slip Ring
Circuits7224
Current per circuit50 A15 A
Speed250 rpm300 rpm meets or exceeds
Voltage600 V380 V
Bore101.6 mm100 mm
View ER Series Through Bore Slip Ring →

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.

What a through-bore slip ring is

A through-bore slip ring is a rotary electrical joint built around a hollow centre, so a drive shaft, pneumatic or hydraulic line, fibre or cable bundle can pass straight through it. The rings are mounted on an insulated sleeve that fits over or around the machine shaft, and the brush blocks sit outside them in a stationary housing. Power, signal and data circuits are combined in one unit, while the bore keeps the rotation axis available for mechanics or services. Bore sizes range from a few millimetres to hundreds of millimetres.

When engineers choose a through-bore slip ring

Engineers choose a through-bore design when the axis of rotation is already occupied, typically by a shaft, a rotary union or a cable that must stay continuous. It is the standard choice for indexing tables, wrapping machines and turntables built around a central column. The trade-off is that larger rings mean higher surface speed, more brush wear and more drag torque at the same rpm, and the unit is bigger than a capsule. Where axial length is the constraint rather than diameter, a pancake design may suit better.

How to specify the Moog AC6098

Send these with your enquiry and an engineer can confirm the right AC6098 variant or an equivalent:

  • Bore diameter and shaft tolerance (mm)
  • Outer diameter and length limits (mm)
  • Circuit count and current per circuit (A)
  • Working voltage and any high-voltage isolation (V)
  • Speed, continuous and peak (rpm)
  • Data or bus protocols to pass, such as Ethernet, CAN or PROFINET
  • Sealing (IP code), temperature (°C) and mounting method

Common mistakes to avoid

  • Sizing the bore to the shaft only, with no allowance for a rotary union or cables that must also pass
  • Mounting the rotor hard on a shaft with radial runout and a separate stator fixing, so the unit is forced to align two axes
  • Forgetting that surface speed rises with diameter, so the rated rpm is lower for larger bores
  • Not stating which circuits need screening or twisted pairs for encoder and fieldbus signals

Moog AC6098: frequently asked questions

What is the Moog AC6098?

Four-inch bore industrial slip ring offering up to 72 signal rings or power rings up to 50 A at 600 VAC. Published series figures include circuits 72, current per circuit 50 A, voltage 600 V, speed 250 rpm. It is made by Moog Inc.; Specify Motion can help source it or propose an equivalent.

Who makes the Moog AC6098?

The Moog AC6098 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 circuits of the Moog AC6098?

The published series maximum circuits is 72. Individual models and sizes in the AC6098 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 AC6098?

Yes. On published figures, ER Series Through Bore Slip Ring is the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.

How do I choose the bore size for a through-bore slip ring?

Start with the shaft diameter and its tolerance, then add anything else that must pass through the centre, such as hoses, a rotary union stem or a fibre. Allow clearance for assembly and for the insulating sleeve. Larger bores raise surface speed, cost and drag torque, so pick the smallest bore that genuinely clears what has to pass through.

Can a through-bore slip ring carry Ethernet as well as power?

Yes. Many through-bore units combine power rings with signal rings designed for industrial Ethernet, using controlled impedance, twisted-pair routing and screening between groups. State the protocol and speed, typically 100 Mbit/s or gigabit, so the supplier can allocate suitable rings and keep them away from motor power. For very high data rates, a contactless or fibre channel may be added.

Further reading: How to select a slip ring · Ethernet through slip rings · Slip rings

Other through-bore slip rings series

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