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DL Series Aluminum Double Diaphragm Coupling – Zero Backlash, High Rigidity for Servo & Stepper Motors
Model Number
Check below, custom
DL-19×27
DL-26×35
DL-34×45
DL-39×50
DL-44×50
DL-56×64
DL-68×75
DL-82×98
- Phone : +86 13431039760
- Wechat : +86 13431039760
- Whatsapp : +86 13431039760
- Email : ella@apexcoupling.com
Product Description
DL Series Aluminum Double Diaphragm Coupling – Zero Backlash, High Rigidity for Servo & Stepper Motors
Factory Direct | High-Strength Aluminum Alloy | 304 Stainless Steel Diaphragm | Zero Backlash | High Torsional Rigidity | 1-80 N·m Torque | 10000 RPM | Clamping Screw Fastening | Low Inertia | Maintenance-Free | OEM Customizable
The Apexcoupling DL series is a high-precision aluminum double diaphragm coupling engineered for demanding motion control applications. Featuring a high-strength aluminum alloy body and a 304 stainless steel double diaphragm, this coupling delivers zero backlash torque transmission with high torsional rigidity and excellent misalignment compensation. The double diaphragm design provides superior compensation for angular, radial, and axial misalignment while maintaining compact dimensions. With clamping screw fastening, H7 precision bore, and maintenance-free operation, the DL series is the ideal solution for encoders, resolvers, stepper motors, servo motors, lead screws, instrumentation, small pumps, feed rollers, and light to medium-duty drive systems.
✅ Zero backlash – no lost motion for precise positioning. Double 304 stainless steel diaphragm – superior misalignment compensation and fatigue resistance. High torsional rigidity – accurate torque transmission for servo systems. Low inertia – ideal for high-speed operation up to 10000 RPM. Maintenance-free – no lubrication required.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Brand | Apexcoupling |
| Model Series | DL (Double Diaphragm Coupling) |
| Type | Flexible / Disc / Diaphragm |
| Structure | Double diaphragm |
| Body Material | High-strength aluminum alloy |
| Diaphragm Material | 304 stainless steel – excellent fatigue resistance, corrosion-resistant |
| Surface Treatment | Anodized |
| Design | Two aluminum hubs + double 304 stainless steel diaphragms with center spacer |
| Backlash | Zero – no rotational clearance |
| Bore Tolerance | H7 – high concentricity and precise shaft fit |
| Bore Diameter Range | 3 – 40 mm (custom available) |
| Outer Diameter Range | 19 – 82 mm |
| Length Range | 27 – 98 mm |
| Rated Torque | 1 – 80 N·m |
| Maximum Speed | 8000 – 10000 RPM (varies by model) |
| Allowable Eccentricity | 0.12 – 0.55 mm |
| Allowable Deflection Angle | 1.5° |
| Allowable Axial Deviation | ±0.18 to ±0.80 mm |
| Misalignment Compensation | Angular, radial (eccentricity), and axial |
| Vibration Damping | Yes – diaphragm absorbs shock and dampens vibration |
| Fastening Method | Clamping screw (positioning screws) |
| Maintenance | None required – maintenance-free |
| Operating Temperature | -30°C to +100°C (depending on application) |
| Customization | OEM – custom bores, keyways, and materials |
| Applicable Industries | Encoders, resolvers, stepper motors, servo motors, lead screws, instrumentation, small pumps, feed rollers, CNC machines, automation equipment |
| Place of Origin | Guangdong, China |
🔧 Custom bores and keyways available. For keyway options, add “K” after the shaft diameter (e.g., DL-26×35-7Kx8K). Contact us with your specifications.
DL Series – Model Range & Specifications
| Model | Outer Diameter (D) mm | Length (L) mm | Bore Range (d) mm | Rated Torque (N·m) | Max Speed (RPM) | Weight (g) |
|---|---|---|---|---|---|---|
| DL-19×27 | 19 | 27 | 3,4,5,6,6.35,7,8 | 1 | 10000 | 14.6 |
| DL-26×35 | 26 | 35 | 5,6,6.35,7,8,9,9.525,10,11 | 1.5 | 10000 | 37 |
| DL-34×45 | 34 | 45 | 6,6.35,8,9,9.525,10,11,12,12.7,14,15 | 3 | 10000 | 77 |
| DL-39×50 | 39 | 50 | 8,9,9.525,10,11,12,12.7,14,15,16,18,19 | 6 | 10000 | 118 |
| DL-44×50 | 44 | 50 | 8,9,9.525,10,11,12,12.7,14,15,16,18,19,20,22 | 9 | 10000 | 144 |
| DL-56×64 | 56 | 64 | 12,14,15,16,18,19,20,22,24,25 | 25 | 10000 | 318 |
| DL-68×75 | 68 | 75 | 15,16,19,20,22,24,25,28,30,35 | 60 | 9000 | 492 |
| DL-82×98 | 82 | 98 | 22,24,28,30,35,38,40 | 80 | 8000 | 1013 |
📐 Additional sizes and custom dimensions available upon request. Contact our engineering team for custom sizing.
Model Designation – DL Series
DL-□□×□□-□□×□□
| Position | Meaning | Example |
|---|---|---|
| DL | Series code – Double Diaphragm Coupling | DL |
| □□×□□ | Outer Diameter (D) × Length (L) | 26×35 |
| □□×□□ | Inner Diameter 1 (d1) × Inner Diameter 2 (d2) | 7×8 |
Keyway Option: Add “K” after the shaft diameter for keyway.
Example: DL-26×35-7K×8K – both bores with keyways
Product Structure
Two Aluminum Hubs – High-strength aluminum alloy, precision-machined, anodized finish.
Double 304 Stainless Steel Diaphragms – Two diaphragm packs connected by a center spacer, providing superior misalignment compensation.
Center Spacer – Connects the two diaphragm packs.
Clamping Screw Fastening – Secure shaft fixation with even clamping force.
💡 How it works: The DL coupling consists of two aluminum hubs connected by two 304 stainless steel diaphragms with a center spacer. Torque is transmitted through the diaphragms, which flex to accommodate angular, radial, and axial misalignment while maintaining high torsional rigidity. The double diaphragm design provides superior compensation for all types of misalignment compared to single diaphragm designs. The design provides zero backlash operation, which is crucial for precision control in encoders, servo systems, and automated machinery.
Double Diaphragm vs Single Diaphragm – Key Differences
| Feature | Double Diaphragm (DL Series) | Single Diaphragm (DS Series) |
|---|---|---|
| Radial (parallel) misalignment | ✅ Yes – superior compensation | ❌ Cannot accommodate |
| Angular misalignment | ✅ Yes – up to 1.5° | ✅ Yes – up to 1° |
| Axial misalignment | ✅ Yes – up to ±0.80mm | ✅ Yes – up to ±0.50mm |
| Torsional rigidity | High | Higher |
| Space requirement | Longer (center spacer required) | Compact – saves space |
| Best for | Applications requiring full misalignment compensation | Space-limited, well-aligned applications |
Selection guideline:
Choose double diaphragm (DL) when parallel (radial) misalignment must be accommodated.
Choose single diaphragm (DS) when space is limited, high torsional rigidity is required, and shafts are well-aligned with no significant parallel misalignment.
Product Features & Advantages
| Advantage | Benefit |
|---|---|
| Zero Backlash | No rotational clearance – precise positioning for encoders, servo motors, and stepper motors |
| Double 304 Stainless Steel Diaphragm | Superior misalignment compensation – accommodates angular, radial, and axial misalignment |
| High Torsional Rigidity | Accurately controls shaft rotation – enables high-precision control for servo systems |
| High-Strength Aluminum Alloy | Lightweight, low inertia – ideal for high-speed operation up to 10000 RPM |
| Zero-Clearance Shaft Connection | Suitable for positive and negative rotation – identical clockwise and counterclockwise characteristics |
| Low Inertia | Lightweight design enables high-speed operation and quick starts/stops |
| Clamping Screw Fastening | Even clamping force, no shaft damage – easy installation |
| H7 Precision Bore | High concentricity and accurate shaft fit – reduces vibration |
| Maintenance-Free | No lubrication required – reduces operating costs |
| Vibration Damping | Diaphragm absorbs shock and dampens vibration – protects sensitive components |
| Widely Used Applications | Encoders, servo motors, stepper motors, lead screws, instrumentation, small pumps |
| OEM Customization | Custom bores, keyways, and materials available |
Why Choose a Double Diaphragm Coupling?
Double diaphragm couplings offer several key advantages for precision applications:
Zero Backlash: Essential for encoders, resolvers, and servo motors where accurate position feedback is required.
High Torsional Rigidity: Maintains system accuracy under load – precise torque transmission for servo control.
Superior Misalignment Compensation: Accommodates angular, radial (parallel), and axial misalignment – reduces stress on bearings and seals.
Low Inertia: The lightweight aluminum design makes them ideal for high-speed operation and quick starts/stops.
Maintenance-Free: No lubrication required, reducing downtime and maintenance costs.
Fatigue Resistance: The 304 stainless steel diaphragm provides excellent fatigue resistance for long service life.
Applications
Encoders & Resolvers – Precision position feedback systems
Servo Motors – High-precision motion control systems
Stepper Motors – Accurate positioning and step transmission
Lead Screws – Precision linear motion systems
Instrumentation – Precision measuring instruments
Small Pumps – Light-duty pump drives
Feed Rollers – Material handling and feeding systems
CNC Machines – Small CNC machines, engraving machines
Robotics – Small robot joint drives
Automation Equipment – Pick-and-place systems, indexing tables
Why Choose Apex Coupling for DL Series Diaphragm Couplings?
| Advantage | Description |
|---|---|
| Factory Direct | Competitive B2B pricing – no middlemen |
| Premium Materials | Aluminum alloy hubs + 304 stainless steel double diaphragm |
| Zero Backlash | Precision performance for encoders, servo motors, and stepper motors |
| High Torsional Rigidity | Accurately controls shaft rotation – enables high-precision control |
| Superior Misalignment Compensation | Double diaphragm design accommodates angular, radial, and axial misalignment |
| Low Inertia | High-speed capability – up to 10000 RPM |
| Clamping Screw Fastening | Secure, even clamping force – no shaft damage |
| H7 Precision Bore | High concentricity and accurate shaft fit |
| Maintenance-Free | No lubrication required – reduces operating costs |
| Wide Model Range | DL-19×27 to DL-82×98 – covers most applications |
| OEM Customization | Custom bores, keyways, and materials available |
FAQ
Q: What is a double diaphragm coupling?
A: A double diaphragm coupling consists of two aluminum hubs connected by two stainless steel diaphragms with a center spacer. It transmits torque while compensating for angular, radial, and axial misalignment with zero backlash and high torsional rigidity.
Q: What is the difference between double and single diaphragm?
A: A double diaphragm coupling can compensate for radial (parallel) misalignment in addition to angular and axial misalignment. A single diaphragm coupling cannot accommodate radial misalignment.
Q: What materials are used?
A: The hubs are made of high-strength aluminum alloy. The diaphragms are made of 304 stainless steel – offering excellent fatigue resistance and corrosion resistance.
Q: Does the coupling have backlash?
A: No. The DL series features zero backlash – no rotational clearance, ensuring precise positioning for encoders and servo motors.
Q: What is the bore tolerance?
A: Standard bore tolerance is H7 for precision shaft fit and high concentricity.
Q: Is the coupling maintenance-free?
A: Yes. The DL series is maintenance-free – no lubrication required.
Q: What are the common applications?
A: Encoders, resolvers, servo motors, stepper motors, lead screws, instrumentation, small pumps, and feed rollers.
Q: Can the coupling compensate for misalignment?
A: Yes. The double diaphragm design compensates for angular (1.5°), radial (0.12-0.55mm), and axial (±0.18 to ±0.80mm) misalignment.
Q: Can I get a custom coupling?
A: Yes. We offer OEM customization – custom bores, keyways, and materials available. For keyway options, add “K” after the shaft diameter (e.g., DL-26×35-7K×8K).
Q: What is the maximum speed?
A: Maximum speed ranges from 8000 to 10000 RPM depending on the model.
Request a Quote
Send us your model (e.g., DL-26×35), bore size, torque, speed, and application details. Our engineers will recommend the optimal model and provide a quotation within 24 hours.
DL series coupling
Double diaphragm coupling
Aluminum diaphragm coupling
Zero backlash coupling
Servo motor coupling
Stepper motor coupling
DL-19×27 DL-26×35 DL-34×45 DL-39×50 DL-44×50 DL-56×64 DL-68×75 DL-82×98
Flexible disc coupling
304 stainless steel diaphragm
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DL series coupling
