DS/DL Aluminum Single/Double Diaphragm Coupling – Zero Backlash, High Rigidity for Servo/Stepper Motors

Factory direct | High-strength aluminum alloy hubs | 304 stainless steel diaphragm | Zero backlash | High torsional rigidity | Ultra-low inertia | Anodized finish | Clamping screw design | OEM/ODM/OBM

The Apexcoupling DS/DL series is a precision diaphragm coupling engineered for high-performance servo motor, stepper motor, and encoder applications. Available in single diaphragm (DS) and double diaphragm (DL) configurations, this coupling features zero backlash operation, high torsional rigidity, and ultra-low inertia – making it ideal for high-speed, high-precision motion control systems. Constructed from high-strength aluminum alloy with a 304 stainless steel diaphragm, the DS/DL series delivers exceptional corrosion resistance, fatigue resistance, and long service life. The clamping screw design ensures secure shaft connection without damaging shafts, while the anodized surface provides enhanced durability.

✅ Zero backlash, high rigidity, and low inertia – specifically designed for servo motors, stepper motors, and encoders. Clockwise and counterclockwise rotation characteristics are exactly the same.

Key Technical Specifications

🔧 Custom bores, keyways, hexagon holes, square holes, spline holes, and special materials available. Contact us with your specifications.

Product Selection & Ordering Guide

Standard Ordering Format:
DS/DL - Outer Diameter (D) × Length (L) - Inner Bore d1 × Inner Bore d2

Example:

• DS-12×12.35-3×3 – Single diaphragm, D=12mm, L=12.35mm, d1=3mm, d2=3mm

• DL-12×15.9-3×3 – Double diaphragm, D=12mm, L=15.9mm, d1=3mm, d2=3mm

Custom Bore Designations:

📐 Standard surface treatment is anodized. Non-standard customizations, special materials, and custom bore types are available – please contact our sales team for details.

DS Single Diaphragm vs DL Double Diaphragm – Which One Do You Need?

Selection guideline:

• Choose DS (single diaphragm) when space is limited, high torsional rigidity is required, and shafts are well-aligned with no significant radial misalignment. The single diaphragm type does not allow eccentricity due to structural reasons .

• Choose DL (double diaphragm) when radial misalignment (eccentricity) must be accommodated, as the double diaphragm can absorb larger installation errors .

⚠️ Important: Single diaphragm couplings cannot accommodate parallel misalignment due to the complex bending required of the lone disc. Take extra care to center the shafts when using DS series couplings .

Product Features & Advantages

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

• Encoders – Precision position feedback, zero backlash

• Food Packaging Machinery – Hygienic, reliable drives

• Metallurgical Equipment – Durable, high-strength connections

• Photovoltaic Equipment – Precision positioning in solar tracking systems

• Woodworking Machinery – High-speed, precision drives

• Chemical Industry – Corrosion-resistant connections

• Semiconductor Equipment – Clean room compatible, high precision

• Food Machinery – Stainless steel diaphragm for hygiene

• Printing Machinery – Register control, high-speed operation

• Railway Equipment – Durable, reliable power transmission

Why Choose Apex Coupling for DS/DL Diaphragm Couplings?

FAQ

Q: What is a diaphragm coupling?
A: A diaphragm coupling is a metal flexible coupling that uses one or more stainless steel diaphragms to transmit torque while compensating for misalignment. It relies on the elastic deformation of the diaphragm to accommodate angular, radial, and axial deviations .

Q: What is the difference between DS (single diaphragm) and DL (double diaphragm)?
A: DS (single diaphragm) is compact with higher torsional rigidity but cannot accommodate eccentricity (radial misalignment) . DL (double diaphragm) can compensate for radial misalignment (eccentricity) as well as angular and axial deviations, making it suitable for applications with larger installation errors .

Q: What does “zero backlash” mean?
A: Zero backlash means there is no rotational clearance between the hubs and the diaphragm. This ensures precise torque transmission with no lost motion – critical for servo motors, stepper motors, and encoders .

Q: What materials are used?
A: The hubs are made of high-strength aluminum alloy with anodized finish. The diaphragm is made of 304 stainless steel for excellent fatigue resistance and corrosion resistance .

Q: What is the surface treatment?
A: Standard surface treatment is anodized (clear anodize) for enhanced corrosion resistance and durability.

Q: What is the clamping screw design?
A: The clamping screw design provides even clamping force around the shaft without damaging it – offering secure shaft connection and easy installation .

Q: What are the rotation characteristics?
A: Clockwise and counterclockwise rotation characteristics are exactly the same – ideal for reversing applications .

Q: Does the coupling require lubrication?
A: No. The DS/DL series is maintenance-free – no lubrication required .

Q: Can I get a custom coupling?
A: Yes. We offer OEM, ODM, and OBM support – custom bores, keyways (K), hexagon holes (F), square holes (S), spline holes (H), and special materials available.

Q: What is the ordering format?
A: Standard format is DS/DL - Outer Diameter (D) × Length (L) - Inner Bore d1 × Inner Bore d2. For custom bores, add suffixes: K (keyway), F (hexagon), S (square), H (spline). Example: DL-12×15.9-3K×3K.

Request a Quote

Send us your configuration (DS single or DL double), outer diameter, length, bore sizes, and any custom bore requirements (keyway, hexagon, square, spline). Our engineers will recommend the optimal model and provide a quotation within 24 hours.