Description
YLD6 YLD Type Flanged Coupling – 24–90mm Bore Rigid Bolted-Flange Shaft Connector to GB5843-86
The YLD6 YLD type flanged coupling is a YLD type flanged coupling with alignment tenon and spacer body designed to connect two co-axial cylindrical shaft ends rigidly through a bolted flange joint, conforming to Chinese national standard GB5843-86. With a 110 mm outer diameter, 24–90 mm bore range, and nominal torque rating of 100 N·m, the YLD6 serves shaft connections in industrial drives where a rigid, zero-backlash connection is required combined with the ability to disconnect the two shaft ends by removing the flange bolts — without moving either shaft axially. Maximum speed rating is 5200 rpm for cast iron hubs and 8000 rpm for cast steel hubs. Overall length including spacer: 388 mm (spacer length L0 = 128 mm). The spacer body provides maintenance access clearance between the two hub faces.
The YL type flanged coupling consists of two identical hub halves, each machined with a bore and keyway to receive one shaft end, and each terminating in a precision-machined circular flange. The two flanges are bolted together with 4×M8 reamed-hole precision bolts that both clamp the faces together and transmit shear torque through the bolt shank. Torque is transmitted from each shaft into its hub through the key-keyway engagement, through the hub body to the flange face, and across the bolted joint to the opposing hub and shaft. The result is a rigid, zero-backlash connection that can be separated by removing the 4 flange bolts without disturbing shaft alignment — an advantage over sleeve couplings that require axial shaft movement for installation or removal. The YLD type’s precision alignment tenon on each flange face ensures that the two hub halves re-centre automatically when the bolts are tightened after maintenance reassembly, eliminating the need for dial indicator realignment.
The YLD6 conforms to GB5843-86, which specifies dimensions for flanged couplings for cylindrical shaft connections transmitting nominal torques from 10 to 20,000 N·m. Bore and keyway dimensions conform to GB3852-1997. The complete YL and YLD flanged coupling range is listed on our product catalog page.
Technical Specifications
| Parameter | Value |
|---|---|
| Model | YLD6 |
| Type | YLD Type Flanged Coupling with Alignment Tenon |
| Standard | GB 5843-86 |
| Bore Range (d) | 24–90 mm |
| Outer Diameter (D) | 110 mm |
| Flange Diameter (D1) | 90 mm |
| Overall Length (L) | 388 mm |
| Spacer / Face Distance (L0) | 128 mm |
| Flange Bolts | 4×M8 |
| Nominal Torque (Tn) | 100 N·m |
| Max Speed – Cast Iron | 5200 rpm |
| Max Speed – Cast Steel | 8000 rpm |
| Rotational Inertia | 0.026 kg·m² |
| Mass | 6.3 kg |
Structure Drawing
Dimension Reference
Rigid Zero-Backlash Connection
The bolted flange joint transmits torque rigidly with zero angular play. Every rotational increment on the driving shaft is replicated exactly on the driven shaft — essential for position feedback and phase-critical drive applications.
Disconnect Without Shaft Movement
Removing the flange bolts disconnects the two shaft ends without moving either shaft axially. This allows motor removal, driven equipment service, or shaft inspection without disturbing bearing housings or shaft alignment.
Cast Iron / Cast Steel Options
Hub material choice of cast iron (5200 rpm) or cast steel (8000 rpm) covers both standard industrial speed requirements and higher-speed applications. The torque rating is the same for both materials.
GB5843-86 Standard Compliance
Full conformance to national standard GB5843-86 ensures dimensional interchangeability with other GB-compliant couplings. Keyway dimensions per GB3852-1997 ensure compatibility with standard motor and driven equipment shaft keyways.
Manufacturing
Typical Applications
- Process pump double mechanical seal drives — spacer length dimensioned to seal cartridge removal clearance
- Chemical plant pump drive connections — API-style spacer coupling for process pump maintenance
- Refinery pump motor connections — spacer coupling for planned seal maintenance without motor disconnection
- Petrochemical drive connections — spacer flanged coupling for rotating equipment with frequent seal service
For custom bore configurations and volume supply, contact our technical team.
Customer Reviews and Case Studies
★★★★★
France — Heavy Pump OEM
The YLD6 spacer coupling is specified for our large API pump range where the 388 mm spacer provides our standard seal removal clearance. At 100 N·m rated torque, it covers all pumps in this class and the alignment tenon simplifies our customers’ maintenance procedures.
— Product Engineer, Lyon
★★★★★
Malaysia — Petrochemical Plant
Installed on large crude oil pump drive connections. The YLD6 spacer allows seal cartridge removal and replacement without motor disconnection — a significant time saving in our planned shutdown schedule.
— Plant Engineer, Kuala Lumpur
★★★★☆
Argentina — Mining Operations
Used on large slurry pump drive connections where spacer access is required for seal replacement. The YLD6 alignment tenon has maintained shaft concentricity through multiple seal change cycles at our copper processing facility.
— Rotating Equipment Engineer, Mendoza
Frequently Asked Questions
What material are YL/YLD flanged coupling hubs made from?
Hubs are available in cast iron (HT200) and cast steel (ZG45). Cast iron is the standard material; cast steel provides higher speed ratings and is used when the maximum speed for the cast iron version is exceeded. The speed rating difference is significant: cast iron at 30 m/s peripheral velocity limit; cast steel at 50 m/s.
How many flange bolts does the YL flanged coupling use?
The number of flange bolts varies by model size: YL1-YL2 use 3 bolts (M6); YL3-YL6 use 3-4 bolts (M8); YL7-YL8 use 4 bolts (M10). Reamed hole bolts are used for precision bolt fit — tightened to a specified torque using a calibrated wrench.
Can the YL type coupling be disassembled without axial shaft movement?
Yes. This is a key advantage of the flanged coupling over the sleeve coupling. The flange bolts are removed and the two hub halves separate at the flange joint face without requiring either shaft to move axially. This allows motor or driven equipment removal for service without disturbing shaft alignment.
What is the Lo dimension on the YL coupling drawing?
L0 is the distance between the outer faces of the two hub flanges — essentially the gap or spacer distance at the coupling centre. For YL type, L0 is short (minimal gap). For YLD type, L0 is the spacer tube length, providing a larger access gap between the two hub faces for maintenance access to seals, bearings, or shaft connections in the coupling region.
Is the YL/YLD flanged coupling suitable for reversing drive applications?
Yes. The rigid bolted flange connection transmits torque equally in both rotational directions. For high-cycle reversing applications, verify that the flange bolt preload is sufficient to prevent fretting at the bolt holes and ensure the keyway bearing stress is within limits for the reversal torque.
Source the YLD6 YLD Flanged Coupling
Ever Power manufactures the YLD6 and the complete YL/YLD flanged coupling range to GB5843-86 direct from our factory. Specify bore sizes, hub type (Y or J₁), and material (cast iron or cast steel) for a prompt technical and commercial response.