Description
YLD2 YLD Type Flanged Coupling – 12–32mm Bore Rigid Bolted-Flange Shaft Connector to GB5843-86
The YLD2 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 80 mm outer diameter, 12–32 mm bore range, and nominal torque rating of 16 N·m, the YLD2 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 7200 rpm for cast iron hubs and 12000 rpm for cast steel hubs. Overall length including spacer: 230 mm (spacer length L0 = 88 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×M6 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 YLD2 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 | YLD2 |
| Type | YLD Type Flanged Coupling with Alignment Tenon |
| Standard | GB 5843-86 |
| Bore Range (d) | 12–32 mm |
| Outer Diameter (D) | 80 mm |
| Flange Diameter (D1) | 64 mm |
| Overall Length (L) | 230 mm |
| Spacer / Face Distance (L0) | 88 mm |
| Flange Bolts | 4×M6 |
| Nominal Torque (Tn) | 16 N·m |
| Max Speed – Cast Iron | 7200 rpm |
| Max Speed – Cast Steel | 12000 rpm |
| Rotational Inertia | 0.0055 kg·m² |
| Mass | 2.4 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 (7200 rpm) or cast steel (12000 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
★★★★★
United Kingdom — Power Transmission Test Facility
The YLD2 spacer coupling allows us to access the intermediate shaft area for temperature and vibration measurement during drive testing without disturbing the drive connection. The alignment tenon ensures our test shaft geometry is maintained throughout the test programme.
— Test Facility Engineer, Coventry
★★★★★
Netherlands — Pump OEM
We use YLD2 spacer couplings on our pump product range where the pump seal requires access space between motor and pump. The spacer body provides 230 mm clearance for seal replacement without motor removal.
— Product Engineer, Delft
★★★★☆
Japan — Industrial Machinery OEM
Installed on drive shaft connections where the spacer provides maintenance access. The YLD2 alignment tenon maintains shaft concentricity accurately on reassembly, which our quality team verifies with a dial indicator on initial installation.
— Equipment Engineer, Nagoya
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 YLD2 YLD Flanged Coupling
Ever Power manufactures the YLD2 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.