ROTEX-GR / GS Elastomer Spider Insert – Polyurethane Coupling Element for Jaw Couplings, 10-4500 N·m

Factory Direct | Premium TPU polyurethane | Interchangeable with KTR ROTEX® | 10-4500 N·m torque | -50°C to +120°C operating range | 92/98 Shore A & 64 Shore D hardness | Oil, ozone & wear resistant | Maintenance-free | OEM customizable

The Apexcoupling ROTEX-GR/GS series is a high-performance polyurethane spider insert (elastomer coupling element) designed for jaw couplings, star couplings, and curved jaw couplings. Fully interchangeable with KTR ROTEX® GR and GS series, these elastomer spiders are the heart of the coupling system – transmitting torque without backlash, absorbing vibration, and compensating for misalignment. Manufactured from premium thermoplastic polyurethane (TPU) with excellent wear resistance, oil resistance, ozone resistance, and thermal stability, these spiders provide long service life in demanding industrial applications. Available in multiple Shore hardness grades (92 Shore A, 98 Shore A, and 64 Shore D) to optimize torsional stiffness and damping characteristics, the ROTEX-GR/GS series is the ideal replacement element for pumps, compressors, conveyors, servo drives, machine tools, and general industrial machinery.

✅ Direct KTR ROTEX® replacement – same dimensions, superior value. Premium TPU material – oil, ozone & wear resistant. -50°C to +120°C operating range – extreme temperature performance. 3 hardness grades – tune stiffness and damping for your application. Zero backlash – press-fit eliminates clearance. Maintenance-free – no lubrication required.

Key Technical Specifications

🔧 Custom sizes and Shore hardness available. Contact us with your specifications.

ROTEX-GR vs ROTEX-GS – Which Series Do You Need?

💡 Choose ROTEX-GR for standard industrial applications. Choose ROTEX-GS for servo drives, precision positioning, and applications requiring enhanced temperature resistance and torsional stiffness.

ROTEX-GR Series – Model Range & Specifications

📐 Additional sizes and custom dimensions available upon request. Contact our engineering team for custom sizing.

ROTEX-GS Series – High-Performance Servo Spider

The ROTEX-GS series features a newly developed high-performance thermoplastic polyurethane with enhanced temperature resistance and pressure resistance . Key features include:

• Backlash-free under prestress – zero clearance for precise positioning 

• 52 Shore D hardness option – for maximum torsional stiffness 

• Temperature resistance up to 120°C – suitable for demanding servo applications 

• Simultaneous compensation of radial, axial, and angular displacements 

• Main applications: Servo hydraulics, test bench technology, machine tools, automation 

✅ The ROTEX-GS series is specifically designed for servo drives requiring zero backlash and high torsional stiffness.

Spider Hardness Selection – Choose the Right Grade

The elastomer spider defines the characteristics of the entire drive system . Selecting the right Shore hardness is critical for optimizing torsional stiffness and damping:

💡 Selection tip: For most industrial applications, 92 Shore A offers the best balance of torque capacity and vibration damping. For high-torque or precision applications, choose 98 Shore A or 64 Shore D .

Product Structure

1. Star-Shaped Elastomer Body – Premium TPU polyurethane with precise tooth geometry.

2. Multiple Teeth / Flaps – 4 to 12 teeth depending on model, engaging with coupling hubs.

3. Center Hole – Accommodates the coupling hub connection.

💡 How it works: The spider insert is installed between the two hubs of a jaw coupling. The spider’s teeth engage with the jaws of the hubs, transmitting torque through radial compression. The press-fit design eliminates backlash. The elastomer flexes to absorb shock, dampen vibration, and compensate for angular, radial, and axial misalignment . By varying the Shore hardness, the coupling system can be optimized for the ideal torsional characteristics .

Product Features & Advantages

Applications

• Pumps – Centrifugal, gear, and diaphragm pumps 

• Compressors – Air and gas compressors 

• Conveyors – Material handling systems 

• Servo Motors – Precision positioning, zero-backlash requirements 

• Machine Tools – CNC machines, milling machines 

• Packaging Machinery – Wrapping and sealing machines 

• Printing Equipment – Register control, high-speed operation 

• Textile Machinery – Spinning and weaving equipment 

• Steel Mills – Rolling mills, heavy equipment 

• Automation Technology – Pick-and-place systems, robotics 

Why Choose Apex Coupling for ROTEX Spider Inserts?

FAQ

Q: What is a ROTEX-GR/GS spider insert?
A: A ROTEX-GR/GS spider insert is a polyurethane elastomer element that fits between the two hubs of a jaw coupling. It transmits torque, absorbs shock, dampens vibration, and compensates for misalignment. It is fully interchangeable with KTR ROTEX® GR and GS series .

Q: What is the difference between GR and GS series?
A: ROTEX-GR is the standard series for general industrial applications. ROTEX-GS is the servo series designed for zero-backlash, high-precision applications with enhanced temperature resistance and torsional stiffness .

Q: What materials are used?
A: The spider inserts are manufactured from premium thermoplastic polyurethane (TPU) – offering excellent wear resistance, oil resistance, ozone resistance, and thermal stability .

Q: What is the temperature range?
A: Standard TPU operates from -30°C to +90°C. High-performance TPU (ROTEX-GS) operates from -50°C to +120°C with instantaneous temperatures up to 150°C .

Q: What Shore hardness options are available?
A: Available hardness grades include 92 Shore A (orange), 98 Shore A (purple/red), 64 Shore D (green), and 52 Shore D (GS series only) .

Q: Does the spider have backlash?
A: No. The press-fit design of the spider into the hubs eliminates backlash .

Q: Is the spider oil-resistant?
A: Yes. The TPU material is highly resistant to oils, greases, and chemicals .

Q: Is this a replacement for KTR ROTEX®?
A: Yes. The GR/GS series is fully interchangeable with KTR ROTEX® GR and GS series – same dimensions, same performance .

Q: What are the common applications?
A: Pumps, compressors, conveyors, servo motors, machine tools, packaging, printing, textile, and general industrial machinery .

Q: Can I get a custom spider?
A: Yes. We offer OEM customization – custom sizes and Shore hardness available.

Request a Quote

Send us your series (GR or GS), model (e.g., GR28, GS38), Shore hardness preference, and application details. Our engineers will recommend the optimal spider and provide a quotation within 24 hours.