Views: 0 Author: Site Editor Publish Time: 2026-08-05 Origin: Site
Industrial automated equipment often needs to deliver multiple kinds of media from stationary pipelines to continuously rotating components. Instead of installing several single‑passage rotary unions, engineers choose multi‑passage rotary union (multi‑channel rotary joint) as an all‑in‑one fluid rotary transmission solution.
A multi‑passage rotary union integrates 2 or more independent isolated flow passages inside one compact housing. Each channel works separately, transmitting hydraulic oil, compressed air, vacuum, cooling water, coolant or nitrogen at the same time, no cross‑contamination between different media. It realizes 360° unlimited continuous rotation for rotating tables, robot joints, machine tool spindles and rotary fixtures.
How Does Multi‑Passage Rotary Union Work?
The whole unit consists of stationary housing, rotating shaft, precision bearings and independent sealing groups for each passage.
1.Stationary housing connects to fixed fluid supply lines, each port corresponds to one separate flow channel.
2.The rotating shaft is mounted on customer rotary equipment, rotating together with machinery.
3.Each channel is isolated by independent sealing sets. High‑precision mechanical seals prevent medium leakage and avoid mixing between passages.
4.Precision bearings support rotary shaft, keep low torque and stable rotation under pressure condition.
Different sealing combinations can be configured: mechanical face seals for high‑pressure hydraulic oil, elastomer seals for low‑pressure air and vacuum. Some hybrid models can combine fluid passages with electrical slip rings for power & signal transmission together.
Core Advantages of Multi‑Passage Rotary Union
Compact integrated design: Replace multiple single‑passage rotary unions, greatly simplify piping layout, save installation space.
Media isolation: Strictly separated channels, zero cross‑leakage for hydraulic oil, air, cooling liquid.
Wide working condition range: Support high pressure, vacuum, variable rotating speed, medium temperature from‑30℃ up to 200℃.
Low‑torque smooth rotation: Precision bearing assembly, extra small starting torque, will not add extra load to servo motor or spindle.
Strong customizability: Standard passages: 2 /4 /6 /8 /12 passages. Custom number of channels, port thread (NPT / BSP / MP / flange), housing material (carbon steel, stainless steel, aluminum alloy) are available.
Multi‑Passage Rotary Union Typical Industrial Applications
1.CNC Machine Tools & Rotary Index Tables
Deliver hydraulic oil for fixture clamping, compressed air for blowing, spindle cooling water. Widely used for multi‑position rotary worktables, hydraulic chucks, rotary fixtures.
2.Robotics & Automation Equipment
Robot rotary joints, rotating manipulators, automated turntables. Simultaneously transmit pneumatic power, vacuum and hydraulic control media. Low‑torque design avoids servo overload alarm.
3.Packaging & Printing Machinery
Rotary filling equipment, rotary die‑cutting machine. Supply compressed air for cylinder actuation and cooling water for roller temperature control.
4.Rubber, Plastics & New‑Energy Industry
Rotary molding equipment, lithium‑battery diaphragm production line, rotating calender rolls. Transport cooling water, hydraulic oil and vacuum for process control.
5.Heavy‑Duty Hydraulic Machinery
Metallurgical turret equipment, engineering rotary actuators. High‑pressure multi‑passage rotary joints handle multi‑circuit hydraulic oil transmission.
Note: Most multi‑passage rotary unions are suitable for hydraulic oil, air, vacuum and cooling water. Please confirm medium, pressure, rotating speed and required passage quantity before selection.
Key Points When Selecting Multi‑Passage Rotary Union
Before inquiry or ordering, please provide below technical parameters for accurate matching:
1.Number of passages required
2.Working medium for each channel (hydraulic oil / air / vacuum / water etc.)
3.Max pressure for every passage
4.Max rotating speed
5.Working temperature
6.Port thread type & size (NPT, BSPP, flange etc.)
7.Installation way: flange mounting or shaft‑mounted
8.Special requirement: low‑torque, stainless steel housing, hybrid electric‑fluid slip ring etc.
FAQ About Multi‑Passage Rotary Union
Q1: Can different media run inside one multi‑passage rotary union?
A: Yes. Every channel is fully isolated. You can run hydraulic oil in one passage, compressed air and cooling water in other passages, as long as correct seal material is chosen.
Q2: Is cross‑leakage risk exist for multi‑channel rotary joint?
A: Quality‑qualified multi‑passage rotary union adopts independent sealing assembly for each channel. Cross‑contamination will not happen under rated working condition. Poor‑quality products may suffer internal cross‑leakage after long‑time operation.
Q3: Can you customize special multi‑passage rotary union?
A: Yes. We support custom‑made multi‑passage rotary unions from 2‑24 passages, special threads, material and hybrid fluid‑electrical integrated structure.
Get Your Custom Multi‑Passage Rotary Union Solution
If you are looking for reliable multi‑passage rotary union for your automation machinery, send us your working parameters. Our engineering team will offer suitable quotation and technical drawing for your project.
