In the world of automation equipment, there is an inconspicuous yet crucial component—it provides continuous power to rotating turntables, continuously transmits control signals to the turntables of wrapping machines, and stably transmits power to the rotating mechanisms of filling machines. This is the through-hole slip ring, also known as a hollow shaft slip ring or through bore slip ring.

    This article organizes the product parameters of standard through-hole slip rings by inner diameter sizes ranging from 12.7mm to 100mm, and systematically introduces their applications across various industrial fields, providing guidance for equipment manufacturers in selection.

Working Principle and Core Value of Through-Hole Slip Rings

    The core feature of a through-hole slip ring is the central through hole. It consists of a rotor (rotating end) and a stator (stationary end) that rotate relative to each other. The inner ring is fixed by set screws, and the outer ring is positioned by a flange, allowing it to be directly mounted on the drive shaft of the rotating equipment without altering the original mechanical structure.

    When the equipment requires continuous 360° rotation, the slip ring uses a precious metal + super-hard gold-plated multi-contact brush wire design to stably transmit power, signals, data, and pneumatic/hydraulic media between the rotating and stationary ends, completely solving the problem of cable entanglement during rotation.

Core Application Fields

1. Turntable Equipment

    Radar turntables, security monitoring turntables, exhibition display turntables, missile launcher rotating mechanisms, astronomical telescope turntables—the common feature of these devices is the need for 360° continuous or arbitrary angle rotation while transmitting multiple channels of power and signals.

Selection Advice:

• • Small security PTZ, display turntable → 12.7-38mm inner diameter series, 6-48 circuits, 1000rpm high-speed type
• • Medium radar turntable, vehicle/shipborne satellite antenna → 50-80mm inner diameter series, 6-120 circuits mixed transmission
• • Large military radar, aerospace measurement and control turntable → 100mm inner diameter series, 1-120 circuits, outer diameter 190mm, supports mixed signal and power transmission, can be integrated with fiber optic rotary joints (FORJ) and high-frequency rotary joints

    The typical applications of 100mm inner diameter slip rings clearly cover heavy-duty turntable scenarios such as various radars, vehicle satellite antennas, ship satellite cables, turntables, virtual 3D, and VR equipment.

2. Wrapping Machine (Packaging & Wrapping Machinery)

    During the rotation of a wrapping machine’s turntable, it is necessary to drive the turntable motor while simultaneously transmitting control system signals to the pre-stretching mechanism of the film frame at the rotating end.

Selection Advice:

• • 12.7mm inner diameter micro series: clearly applied in packaging machines, automatic toothpick packaging machines, fully automatic box folding machines, automatic assembly machines, intelligent dispensing machines, mobile phone film applicators, rotating LED lights, etc.
• • 25.4-38mm inner diameter series: 12-48 circuits optional, 5A/10A current per circuit, aluminum alloy housing, IP54 protection, 1000rpm high-speed type meets the pace of high-speed wrapping production lines
• • Pneumatic-electric hybrid: can be integrated with pneumatic rotary joints, allowing the wrapping machine turntable to obtain both power and compressed air simultaneously

3. Filling Machines

    A rotary filling machine’s turntable has dozens of filling stations, each requiring independent motor drive, solenoid valve control, and sensor signal feedback.

Selection Advice:

• • Small filling actuators (capping heads, labeling turrets, CCD vision inspection turntables) → 12.7mm
• • Medium filling turntables → 50-60mm inner diameter series, 24-72 circuits, 2A-25A mixed current
• • Food-grade environments: IP65 waterproof type optional, supports integration with hydraulic rotary joints to achieve power + signal + cleaning fluid three-in-one transmission

    The typical applications of 100mm inner diameter slip rings in the packaging field also include bottle blowing machines, lamp inspection machines, and other rotating equipment.

4. Robots

    The sixth axis (end effector rotating shaft) of industrial robots, AGV charger rotary joints, collaborative robot joints, pipeline inspection robots—these are all typical application scenarios for through-hole slip rings.

Selection Advice:

• • Robot end/joint → 12.7mm inner diameter micro series: minimum outer diameter of only 53mm (Type I) / 60mm (Type II), light weight, low moment of inertia, supports 6-48 circuits, 2A-20A
• • Successfully applied in pipeline camera robots, underwater surveillance cameras, pipeline detectors, industrial endoscopes, CCD vision inspection equipment, intelligent equipment machine vision systems
• • The typical application list for the 100mm inner diameter series also clearly includes various robots and manipulators, and can integrate servo systems, encoders, CANBUS, Profibus, USB2.0, Gigabit Ethernet, HD-SDI, and other signal protocols

5. Automated Production Lines

    Modern automated production lines consist of multiple rotating stations connected in series—rotary tables (Index Table), automatic assembly lines, lithium battery winding machines, rotary labeling machines, dispensing machines, screw locking machines, etc. Each rotating station requires independent power drive and signal feedback. Through-hole slip rings are the core component for achieving multi-station continuous rotation and eliminating cable entanglement, ensuring 24-hour uninterrupted operation of the entire line.

Selection Advice:

• • Micro rotating stations (dispensing machines, labeling machines, LED rotating lights, mobile phone film applicators) → 12.7mm inner diameter series, 6-48 circuits, 2A-20A, 1000rpm high-speed response
• • Medium rotary tables/assembly line turntables → 25.4-60mm inner diameter series, 12-108 circuits, 5A-25A, meeting the mixed power supply needs of multi-station sensors and pneumatic components
• • Large automated production line rotating equipment (lithium battery winding machines, pole piece slitting rotating stations, CNC machining center turntables) → 80-100mm inner diameter series, 6-120 circuits, supports industrial fieldbus signals (Profibus, Modbus, Gigabit Ethernet, etc.) mixed with power transmission

    The 12.7mm micro series has been clearly applied in automated production line equipment such as automatic assembly machines, intelligent dispensing machines, and fully automatic box folding machines; the 100mm series supports 129 circuits of industrial fieldbus mixed transmission, covering the complex signal requirements of large automated production lines.

6. Other Important Application Fields

In addition to the above five core scenarios, through-hole slip rings are also widely used in:

    The official application list for 100mm inner diameter slip rings covers: various radars, security equipment, entertainment equipment, robots and manipulators, tethered balloons, wind power equipment, bottle blowing machines, lamp inspection machines, various turntables, amusement equipment, virtual 3D/VR, vehicle/shipborne satellite antennas, cable reels, window cleaning equipment, rotating screens/revolving restaurants, electric construction machinery, etc.

Size Selection Quick Reference

Size Selection Quick Reference:

 Selection Tips

    The 100mm inner diameter slip ring supports 129 channels of industrial fieldbus mixed transmission, compatible with Analog, RS232/RS485, Profibus, Modbus, USB2.0, Gigabit Ethernet, HD-SDI 1080P, and other signal protocols. If standard models cannot fully match your requirements for aperture, number of circuits, current, protection level, or signal type, deep customization is supported—including the integrated hybrid integration of pneumatic/hydraulic rotary joints, fiber optic rotary joints (FORJ), and RF rotary joints.