What a 25 mm bore slip ring is used for
When the machine has a shaft you cannot cut, or when cables, air lines or hydraulic hoses must run through the axis of rotation, a through-bore slip ring is the practical answer. The 25 mm class is the most common size in industrial equipment: large enough to pass a 1-inch shaft plus a cable bundle, small enough to fit inside a standard machine envelope.
Specifications — GK2586 series
| Parameter | Value | Notes |
|---|---|---|
| Bore (through hole) | 25.4 mm | 1 inch nominal; allow clearance for shaft tolerance |
| Outer diameter | 86 mm | Check bracket space before ordering |
| Circuit count | 6 / 12 / 18 / 24 / 36 | Other counts available on request with drawing |
| Current per ring | 5 A / 10 A / 20 A | 20 A applies from 25.4 mm bore upward |
| Voltage | 440 V | Dielectric strength 800 VAC (power), 300 VAC (signal) |
| Rotation speed | Up to 250 rpm | Confirm duty cycle for continuous operation |
| Life expectancy | 20 / 50 / 80 million revolutions | Three tiers, selected at order |
| Operating temperature | −30 to +80 °C | Special ranges on request |
| Protection class | IP51 / IP65 / IP68 | IP65 and IP68 are sealed variants |
| Contact material | Six-element alloy wire, gold plated | Precious-metal contacts for low noise |
Specifications above are for the standard GK2586. Modified bore, flange, lead length and connector types are quoted per drawing.
Typical applications
- CNC rotary tables and index tables — power and encoder signals to a continuously rotating table
- Packaging and filling machines — sensors and heaters on the carousel, no cable wrap
- Cable reels and winches — power down the drum while it turns
- Wind turbine nacelles — pitch and yaw signal transfer
- Industrial test stands — instrumentation on a rotating fixture
- Robotic positioners — seventh-axis and turntable joints
How to select the right bore size
Bore size is decided by what has to pass through it, not by the load. Three things usually set the minimum:
- Shaft diameter — the bore must clear the shaft with a small margin for tolerance and thermal expansion. A 25 mm shaft needs a 25.4 mm bore, not a 25 mm bore.
- Cable or hose bundle — add the outer diameter of everything that runs down the centre, plus bending radius clearance.
- Mounting and service access — leave room to reach the terminals; a tight bore often means a tight wiring job.
Frequently asked questions
Can I run 20 A on all 36 circuits at the same time?
Total current is limited by heat, not only by the per-ring rating. 20 A per ring is the individual limit on this bore size; for high total loads, tell us the simultaneous current profile and we will confirm the thermal design before quoting.
Does the bore need to be exactly 25.4 mm?
No — custom bores are machined to order. Send the shaft diameter and tolerance and we will match the bore. Standard 25.4 mm is the fastest option because it is already in production.
Can I add IP65 or IP68 sealing?
Yes. Both are available as sealed variants on this series. Tell us the environment (washdown, dust, temporary immersion) and we will recommend the right class — IP54 is not offered on electrical units; the range starts at IP51 and goes to IP65 / IP68.
What lead time should I expect?
Standard configurations typically ship in about one week. Modified units depend on the drawing and quantity — we confirm the exact date with the quotation.
Can I order a single unit to test?
Yes. Minimum order is one piece, including custom configurations. Many customers start with one unit for bench testing before committing to a production run.
Related products
Need a 25 mm bore slip ring for your machine?
Send your shaft diameter, circuit count and current per ring — you will get a technical answer and a quotation, usually within 5 hours.
