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Spare parts · coolant and lubrication
Rotary unions for through-spindle coolant to order
A rotary union feeds coolant, air or MQL aerosol into the rotating spindle and on through the drawbar to the tool. Its mechanical seals run at high speed and under pressure, so over time leakage appears at the drain, and with it the risk of emulsion entering the spindle. We supply rotary unions from families such as Deublin, Duff-Norton and Rotoflux, coolant tubes and spindle lubrication parts to order, identified from the model.
Range
What we supply for coolant feed and lubrication
The rotary union, the coolant tube in the drawbar and the bearing lubrication work as one system: a leak at one end often means wear at the other. So we specify the parts together, from a new union to a repair kit and tubes.
Rotary unions for coolant
Single-passage unions for through-spindle coolant on machining centres, including high-pressure internal cooling. Deublin, Duff-Norton, Rotoflux and other families, identified from the model number on the union body.
Unions for air and MQL
Versions for air blast, minimum quantity lubrication (MQL) and alternating media, and unions rated for running dry. The medium is the key parameter in selection.
Repair kits and mechanical seals
For many models, repair kits with mechanical seals and bearings are available. We advise whether a repair kit or a new union is the better choice in your case.
Coolant tubes and drawbar parts
Coolant tubes running through the drawbar, sealing sleeves and union rotors. A worn tube causes rotor runout at the union and accelerates seal wear.
Oil-air lubrication
Parts of spindle oil-air lubrication systems: metering units, mixing blocks, tubes, fittings, filters and flow sensors. A steady oil supply is a condition for long bearing life at high speed.
Grease lubrication
For grease-lubricated spindles: special spindle greases for the specific bearing arrangement, and metering parts where the design provides for them.
Wear signs and selection
When to replace a rotary union and how to specify it
The main sign of wear is leakage from the union's drain port: the mechanical seals are already letting the medium through. The drain has to stay open, otherwise coolant is pushed into the spindle. On machining centres doing deep-hole drilling with internal coolant, a sound rotary union is a matter of uninterrupted production. Points to note and data we need:
- Coolant leaking from the drain or emulsion on the rear of the spindle
- Noise or heat at the union, fluctuating coolant pressure
- Model number and manufacturer from the union body
- Medium: coolant, air, MQL, dry running
- Maximum speed and pressure, thread type and direction of rotation
- Spindle or machine model, photo of the mounting position
Ordering
How to order a rotary union
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1
Photo and marking
Send a photo of the union with its marking, the spindle nameplate and the machine model. If the marking is unreadable, photos of the rotor thread and connections.
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2
Identification
We determine the exact model or a compatible version by speed, pressure, medium and thread.
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3
Quote
We offer a new union, a repair kit or an equivalent, with price. Availability and delivery time are confirmed with the quote.
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4
Shipping and fitting
We ship by courier, or fit the union and check rotor runout, the coolant tube and the drain.
Why us
Why order rotary unions from us
A rotary union is specified by several parameters at once, and an error in any of them shortens the life of the new part. We check the data before ordering and help with fitting.
European sourcing
Rotary unions and repair kits in original or equivalent quality from the European market.
Compatibility check
We check thread, direction of rotation, medium and speed against your spindle before the order is placed.
Fitting with tube check
During fitting we check the coolant tube and rotor runout, which extends the life of the new union.
Shipping across Europe
Courier or freight forwarder to any address in Europe and worldwide.
Simple paperwork
Within the EU no customs formalities; outside the EU we help with the export documents.
Related pages
Related parts and services
If coolant from the union has already entered the spindle, check the bearings and seals as well. Useful pages:
Questions
Questions about rotary unions
Most often by coolant leaking from the drain port, noise or heat at the union and unstable coolant pressure. Treat even a small leak as a signal to replace it.
Yes. We need the spindle model, photos of the union and rotor thread, the medium, speed and pressure. From that we identify the matching model or a compatible version.
That depends on the model and the condition of the body. For many unions a repair kit fully restores function; for others a new union is more economical. We compare both in the quote.
Yes: metering units, mixing blocks, tubes, fittings, filters and flow sensors, specified from the lubrication diagram of your spindle or machine.
Yes, by arrangement. Replacing a rotary union is usually done without removing the spindle, so your own maintenance team can also fit it with our guidance.
Request
Order a rotary union
Send a photo of the union with its marking and the machine model, and we identify it and offer the options.
Scope
Our spindle services
Every operation below is done in our own workshop in Germany. Follow a link for what it involves and what we need from you.
Machine brand
Machine brands
We are independent and work with spindles of every builder. These are the makes whose spindles come across the bench most often.