Overview
The R+W EK7/20/B/19.05PFN/26 is a compact elastomer spider coupling engineered for space-restricted industrial applications. Built with precision-molded, wear-resistant polymer and high-strength aluminum or steel hubs, this coupling delivers smooth, backlash-free operation with excellent vibration damping characteristics. The expanding shaft design with internally tapered clamping element ensures secure mounting without the need for lateral access holes.
Key Features
- Compact axial installation design — ideal for space-constrained applications with easy assembly and dismounting via unique screw design
- Elastomer insert — precision-molded, wear-resistant, thermally stable polymer delivers vibration damping and backlash-free performance
- Expanding shaft hub — tapered clamping element on one side; clamping hub with ISO 4762 screw on the other for flexible mounting configurations
- Electrical isolation — elastomer element isolates electrical potential between shafts, protecting sensitive equipment
- Misalignment compensation — radial and axial displacement tolerance prevents binding and extends component lifespan
- Curved jaw design — concentrically machined hubs with curved jaws for consistent load distribution
Technical Specifications
- Coupling Type: Elastomer Spider (EK7 Series)
- Part Number: EK7/20/B/19.05PFN/26
- Hub Material: High-strength aluminum (series up to 450) or steel (series 800 and above)
- Expanding Shaft/Cone: Steel
- Elastomer Insert: Precision-molded, thermally stable polymer
- Bore Diameter: 19.05 mm (3/4″ nominal)
- Design: Compact, short axial length; one expanding shaft side with internally tapered clamping element
- Assembly: Clamping hub side uses ISO 4762 screw; expanding shaft side uses tapered cone
- Backlash: Backlash-free
- Tightening Torque Clearance: Shaft-to-hub overall clearance 0.01–0.05 mm (shaft oiled)
Typical Applications
- Machine tool spindles and motor drives where space is restricted
- Servo and precision motion control systems requiring low-backlash coupling
- Pump and compressor shaft connections needing vibration isolation
- Industrial automation and robotics with frequent assembly/disassembly cycles
- Equipment requiring electrical isolation between drive and driven components
Compatibility & Replacements
Compatible With
- Motors and servo drives with shaft sizes suitable for 19.05 mm bore diameter
- Pump and compressor shafts with corresponding bore and tapered shaft profiles
- Machine tool spindles and precision rotary equipment
- Industrial automation systems requiring vibration damping and misalignment tolerance
Replaces / Drop-In Replacement For
- Other R+W EK7 series couplings with equivalent bore diameter and hub configuration
- Verify exact replacement compatibility with original equipment documentation or your system integrator, as bore diameter and hub material specifications must match precisely
Works With
- ISO 4762 socket head cap screws (clamping hub side)
- Tapered shaft and cone assembly (expanding shaft side)
- Standard shaft oiling procedures for optimal performance
- Industrial automation platforms and motion control systems using flexible coupling isolation
