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DLK Stainless Steel Bellows Coupling with Shrink Disc – Zero Backlash, High Torque for Servo Motors & CNC
Model Number
Check below, customize
| Specification | Shaft Bore D1 (mm) | Shaft Bore D2 (mm) | Outer Diameter (mm) | Overall Length (mm) |
|---|---|---|---|---|
| DLK Bellows | 16 | 16 | 40 | 50 |
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Product Description
DLK Stainless Steel Bellows Coupling with Shrink Disc – Zero Backlash, High Torque for Servo Motors & CNC
Factory direct | Stainless steel bellows | Shrink disc locking | Zero backlash | 26 N·m torque | 8000 RPM | H7 bore | 12.9 grade screws | Maintenance-free | OEM customizable
The Apexcoupling DLK series is a high-performance stainless steel bellows coupling with shrink disc (shrink disc) locking – engineered for precision power transmission in servo motor, stepper motor, resolver, and CNC applications. Featuring a stainless steel bellows that provides excellent flexibility and corrosion resistance, combined with a shrink disc locking system for secure, backlash-free shaft-to-hub connection, this coupling delivers zero backlash, high torsional rigidity, and superior misalignment compensation. The bellows structure compensates for radial, angular, and axial deviations while maintaining constant velocity rotation in both clockwise and counterclockwise directions. With H7 precision bore, 12.9 grade high-strength screws, and maintenance-free operation, the DLK series is the ideal solution for CNC machine tools, food packaging machinery, metallurgical equipment, photovoltaic systems, woodworking machinery, chemical industry, semiconductor equipment, printing machinery, and railway applications.
✅ Zero backlash – ideal for positive and negative rotation. Stainless steel bellows – corrosion-resistant, flexible, and durable. Shrink disc locking – secure, keyless shaft connection. Maintenance-free – no lubrication required.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Brand | Apexcoupling |
| Model Series | DLK (Bellows Coupling with Shrink Disc) |
| Type | Flexible / Bellows / Shrink Disc |
| Bellows Material | Stainless steel – corrosion-resistant, flexible |
| Hub Material | S45C carbon steel |
| Surface Treatment | Polished (standard) |
| Locking Method | Shrink disc (shrink disc) – keyless friction-lock |
| Fastening Method | Clamping screws (12.9 grade) |
| Bore Tolerance | H7 / H8 (precision fit) |
| Backlash | Zero – no rotational clearance |
| Rotation Characteristics | Identical clockwise and counterclockwise |
| Misalignment Compensation | Radial, angular, and axial |
| Applicable Industries | CNC machine tools, servo motors, stepper motors, resolvers, food packaging, metallurgy, photovoltaic, woodworking, chemical, semiconductor, printing, railway |
| Customized support | OEM |
| Place of Origin | Guangdong, China |
🔧 Custom bores, keyways, hexagon holes, square holes, and special materials available. Contact us with your specifications.
DLK Series – Model Range & Specifications
| Model | Max Bore d1/d2 (mm) | ΦD (mm) | L (mm) | L1 (mm) | M | Tightening Torque (N·m) | Rated Torque (N·m) | Max Torque (N·m) | Max Speed (rpm) | Allowable Radial Deviation (mm) | Allowable Angular Deviation (°) | Allowable Axial Deviation (mm) | Weight (g) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| DLK14-40 | 16 | 40 | 55 | 19 | M3 | 2 | 13 | 26 | 8000 | 0.15 | 2 | 1 | 231 |
| DLK14-55 | 20 | 55 | 65 | 22 | M4 | 3.5 | 28 | 56 | 6000 | 0.20 | 2 | 1.5 | 485 |
| DLK14-65 | 28 | 65 | 76 | 27 | M5 | 6 | 60 | 120 | 5000 | 0.25 | 2 | 1.5 | 787 |
| DLK14-80 | 32 | 80 | 88 | 32 | M6 | 10 | 80 | 160 | 4500 | 0.28 | 2 | 1.5 | 1512 |
| DLK14-90 | 42 | 90 | 88 | 32 | M6 | 10 | 90 | 180 | 4000 | 0.30 | 2 | 1.5 | 1800 |
| DLK14-110 | 56 | 110 | 103 | 41 | M8 | 30 | 110 | 220 | 3500 | 0.35 | 2 | 1.5 | 3000 |
| DLK14-123 | 60 | 123 | 110 | 41 | M8 | 30 | 123 | 246 | 3000 | 0.35 | 2 | 1.5 | 4200 |
| DLK14-133 | 60 | 133 | 114 | 50 | M8 | 30 | 133 | 266 | 3000 | 0.35 | 2 | 1.5 | 5600 |
| DLK14-157 | 70 | 157 | 141 | 61 | M8 | 30 | 157 | 314 | 2500 | 0.35 | 2 | 1.5 | 8200 |
| DLK14-200 | 100 | 200 | 195 | 80 | M10 | 75 | 200 | 400 | 2000 | 0.40 | 2 | 1.5 | 23000 |
📐 Custom bores and dimensions available. H7/H8 standard公差. Contact our engineering team for custom sizing.
Model Designation – DLK Series
DLK14-□□-□□×□□
| Position | Meaning | Example |
|---|---|---|
| DLK | Series code – Bellows Coupling with Shrink Disc | DLK |
| 14 | Series variant | 14 |
| □□ | Outer Diameter (D) | 40 |
| □□ | Length (L) | 55 |
| □□ | Inner Diameter 1 (d1) | 16 |
| □□ | Inner Diameter 2 (d2) | 16 |
Example: DLK14-40×55-16×16 = Outer diameter 40mm, Length 55mm, Bore 16mm × 16mm
Customization Options:
Add K after bore size for keyway: DLK14-40×55-16K×16K
Add F for hexagon hole: DLK14-40×55-16F×16F
Add S for square hole: DLK14-40×55-16S×16S
Add H for spline hole: DLK14-40×55-16H×16H
Product Structure – Bellows + Shrink Disc
Stainless Steel Bellows – Precision-welded, corrosion-resistant, provides flexibility and misalignment compensation.
Two Hubs – S45C steel, precision-machined with H7 bore.
Shrink Disc (胀套) Locking System – Keyless friction-lock connection for secure shaft-to-hub attachment.
12.9 Grade High-Strength Screws – Smooth, burr-free, no loosening under vibration.
💡 How it works: The DLK coupling combines a stainless steel bellows with a shrink disc locking system. The bellows transmits torque while flexing to accommodate radial, angular, and axial misalignment – maintaining constant velocity rotation in both directions. The shrink disc provides a secure, keyless friction-lock connection between the hub and shaft, eliminating keyways and stress concentrations. The result is a zero-backlash, high-torsional-rigidity coupling that is ideal for servo motors, stepper motors, resolvers, and precision CNC applications.
Product Features & Advantages
| Advantage | Benefit |
|---|---|
| Stainless Steel Bellows | Corrosion-resistant, excellent flexibility, long service life – suitable for harsh environments and reversing applications |
| Zero Backlash | No rotational clearance – precise positioning for servo motors, stepper motors, and resolvers |
| Shrink Disc Locking | Keyless friction-lock – no keyways, no stress concentrations, easy installation and removal |
| 12.9 Grade High-Strength Screws | Smooth, burr-free, no loosening under vibration – secure clamping force |
| H7 Precision Bore | High concentricity, accurate shaft fit – reduces vibration |
| Identical CW/CCW Rotation | Symmetrical performance in both directions – ideal for reversing drives |
| Misalignment Compensation | Compensates radial (up to 0.40mm), angular (up to 2°), and axial (up to 1.5mm) deviations |
| Maintenance-Free | No lubrication required – reduces operating costs |
| High Torsional Rigidity | Accurate torque transmission – maintains system precision |
| Wide Torque Range | 13–200 N·m rated, 26–400 N·m max – covers light to medium-duty applications |
| High Speed Capability | Up to 8000 RPM – suitable for high-speed precision applications |
| OEM Customization | Custom bores, keyways, hexagon/square holes, and special materials |
| Corrosion Resistant | Stainless steel bellows – ideal for food, chemical, and outdoor applications |
Why Bellows Couplings Are Ideal for Servo Motors & Resolvers
Bellows couplings are widely regarded as the ideal solution for servo drives due to their unique combination of properties [1†L24-L26]:
| Requirement | How Bellows Coupling Meets It |
|---|---|
| Zero backlash | No rotational clearance – precise positioning |
| High torsional stiffness | Accurate torque transmission – maintains system rigidity |
| Low moment of inertia | Enables rapid acceleration and deceleration |
| Misalignment compensation | Compensates radial, angular, and axial deviations |
| Constant velocity | Identical clockwise and counterclockwise rotation |
| Corrosion resistance | Stainless steel bellows – suitable for harsh environments |
✅ The DLK series is specifically designed for servo motors, stepper motors, resolvers, and encoders – providing the zero backlash, high torsional stiffness, and precision required for demanding motion control applications [1†L24-L26].
Shrink Disc Locking – Keyless Advantage
| Feature | Shrink Disc Locking (DLK) | Traditional Keyway |
|---|---|---|
| Keyway required | ❌ No – keyless | ✅ Yes |
| Backlash | Zero – friction-lock | Clearance → backlash |
| Stress concentration | None – uniform pressure | High – at keyway corners |
| Shaft strength | Full diameter – no weakening | Reduced by keyway |
| Installation | Simple – tighten screws | Key fitting, may require filing |
| Removal | Easy – removal thread holes | May require pullers |
| Reusability | Yes – multiple times | Keyway wears over time |
| Corrosion protection | Contact surfaces seal against corrosion | No |
Applications
CNC Machine Tools – Spindle drives, feed axes, high-precision positioning
Servo Motors – High-precision motion control, zero backlash requirement
Stepper Motors – Accurate positioning, no lost motion
Resolvers & Encoders – Precision position feedback, zero backlash
Food Packaging Machinery – Corrosion-resistant, hygienic drives
Metallurgical Equipment – High-torque, high-speed applications
Photovoltaic Systems – Solar tracking, precision positioning
Woodworking Machinery – High-speed, precision drives
Chemical Industry – Corrosion-resistant applications
Semiconductor Equipment – Clean room compatible, high precision
Printing Machinery – Register control, high-speed operation
Railway Equipment – Durable, reliable power transmission
Why Choose Apex Coupling for DLK Bellows Couplings?
| Advantage | Description |
|---|---|
| Factory Direct | Competitive B2B pricing – no middlemen |
| Premium Materials | Stainless steel bellows + S45C steel hubs – durable and corrosion-resistant |
| Shrink Disc Locking | Keyless connection – zero backlash, easy installation |
| Zero Backlash | Accurate position feedback – no lost motion |
| High Torsional Rigidity | Maintains system accuracy under load |
| Wide Model Range | DLK14-40 to DLK14-200 – covers most industrial needs |
| Maintenance-Free | No lubrication required – reduces operating costs |
| OEM Customization | Custom bores, keyways, hexagon/square holes, and materials |
FAQ
Q: What is a bellows coupling with shrink disc?
A: A bellows coupling with shrink disc combines a stainless steel bellows for flexibility and misalignment compensation with a shrink disc (shrink disc) locking system for secure, keyless shaft-to-hub connection. It provides zero backlash, high torsional rigidity, and corrosion resistance.
Q: What is the advantage of the shrink disc locking system?
A: The shrink disc provides a keyless friction-lock connection – eliminating keyways, stress concentrations, and backlash. It allows for easy installation and removal, and the assembly is reusable multiple times.
Q: What materials are used?
A: The bellows is made of stainless steel – corrosion-resistant and flexible. The hubs are made of S45C carbon steel with polished finish.
Q: What is the torque and speed range?
A: Rated torque ranges from 13–200 N·m (max 26–400 N·m). Maximum speed ranges from 2000–8000 RPM depending on model.
Q: What misalignment can the coupling compensate for?
A: The bellows structure compensates for radial (up to 0.40mm), angular (up to 2°), and axial (up to 1.5mm) deviations.
Q: Does the coupling have backlash?
A: No. The DLK series features zero backlash – no rotational clearance, ensuring precise positioning for servo motors, stepper motors, and resolvers.
Q: What are the rotation characteristics?
A: Clockwise and counterclockwise rotation characteristics are exactly the same – ideal for reversing applications.
Q: Is the coupling maintenance-free?
A: Yes. No lubrication required – reduces operating costs and maintenance schedules.
Q: What is the bore tolerance?
A: Standard bore tolerance is H7/H8 for precision shaft fit. Custom tolerances available on request.
Q: Can I get a custom coupling?
A: Yes. We offer OEM customization – custom bores, keyways, hexagon/square holes, and special materials available.
Request a Quote
Send us your model size (e.g., DLK14-40), bore size, torque, speed, and application details. Our engineers will recommend the optimal model and provide a quotation within 24 hours
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