SHAFT COUPLINGS

Product catalog summary

Shaft Couplings Overview
Shaft couplings are engineered for zero backlash and precise torque transfer, featuring high torsional stiffness and low moment of inertia. They are suitable for applications from servo drives to general machine tool design. ENEMAC offers various couplings, including metal bellows and jaw couplings, each tailored for specific applications.

Characteristics of Shaft Couplings

Zero backlash and precise torque transfer.
Low moment of inertia and high balancing quality.
Excellent performance at high speeds.
Compensation for shaft misalignments with minimal restoring forces.
Metal bellows provide maximum torsional rigidity and are wear-free up to 623 K.
Polyurethane inserts are plug-in, oscillation dampening, and operate up to 393 K.
Compact design with flexible application possibilities.
Wide range of types and sizes available.
High-quality production ensures long lifespan.

Comparison: Metal Bellows vs. Jaw Couplings

Metal bellows offer high torsional stiffness and minimal restoring forces, ideal for high precision applications.
Jaw couplings are vibration absorbing and allow blind assembly, suitable for flexible applications.
Temperature range for metal bellows is up to 623 K, while jaw couplings operate from 243 K to 393 K.
Metal bellows are suitable for high-speed applications up to 20,000 rpm.

Dimensioning of Shaft Couplings

Nominal torque (TKN) indicates maximum load for prolonged alternating-stress strength.
Moment of inertia values are provided for medium hub-bores.
Torsional rigidity is expressed in Nm/arc min, allowing calculation of twisting angle errors.
Maximum shaft alignment is crucial for coupling durability.
Axial, angular, and lateral displacements should be within permissible limits to avoid excessive wear.

Technical Information and Definitions

Coupling size is typically chosen based on torque requirements.
Torsional rigidity is critical for high precision applications.
Shaft diameter must be checked against hub bore limits for proper fit.
Coupling lifetime is influenced by torque and shaft misalignment.
In exceptional cases, couplings can be temporarily overloaded by up to 100%.

Specifications

Load Capacity: Couplings can handle up to twice the nominal torque for short periods, but hub-bore connection must be calculated separately.
Bearing Loads: Couplings' flexibility prevents significant bearing loads, reducing wear and repair needs.
Operating Temperatures: Metal bellows operate up to 573 K, while polyurethane inserts have limits of 363 K and 393 K.
Speeds: Suitable for high speeds up to 20,000 rpm, with some types capable of over 25,000 rpm.
Maintenance: Generally maintenance-free, but polyurethane inserts should be replaced periodically under critical conditions.

Procedures

Shaft Alignment: Axial and angle displacements are easy to measure; lateral displacement is determined using a dial gauge.
Shaft-Hub Connection: Couplings are typically supplied finish-bored; connection should be lightly oiled to prevent corrosion.
Radial Clamping Hub: Simple fitting by tightening a single clamping screw; admissible seat clearance is specified.
Conical Hub: Assembled using multiple screws, ensuring even tightening to prevent uneven draw-on.
Disassembly: Involves loosening screws and using push-off threads for hub removal.

Standards and Recommendations

Material and Design: Stainless steel bellows provide high torsional stiffness and flexibility; design minimizes inertia and is maintenance-free.
Connection Methods: Special press-fit and welding methods ensure durability under harsh conditions.
Balancing: Standard balancing quality is Q 16, with options for higher precision balancing.

Key Data from Tables and Diagrams

Diagrams illustrate shaft alignment and coupling installation.
Technical data sheets provide specific values for permissible displacements and torque capacities.

Model-Specific Features

EWA: Cost-effective standard type with 6-corrugation bellows and easy assembly clamping hub.
EWB: Short design with high torsional stiffness and easy assembly.
EWF/EWC: Wear and maintenance-free, available in full steel or stainless steel versions.
EWG: Designed for direct mounting in hollow shafts with internal axial buffer.
EWH: Features conical hubs on both sides, suitable for high-speed applications.
EWHL: Straight bellows with low restoring forces and high torsional rigidity.
EWI: Splitted hub design for simple installation, zero backlash, and customizable length.

Performance Parameters

Nominal Torque: Ranges from 2 Nm to 2500 Nm depending on the model.
Moment of Inertia: Varies across models, affecting the dynamic response of the system.
Max Speed: Up to 25,000 min-1 for certain models, suitable for high-speed applications.
Max Shaft Displacement: Axial and lateral displacements are specified for each model, ensuring flexibility in alignment.

Specifications

Metal bellows couplings (EWU) and jaw couplings (EWD and EWE) are detailed, with metal bellows made of stainless steel and high tensile aluminum components, operating from -40°C to 300°C.
Jaw couplings are flexible, zero backlash, and use a polyurethane insert with different Shore hardnesses.

Materials

Metal bellows couplings use stainless steel for bellows and high tensile aluminum for other components.
Jaw couplings use high-strength aluminum for hubs and heat-treated steel for certain parts, with polyurethane inserts available in various hardnesses.

Procedures

Assembly of EWE couplings requires mounting hub halves on shaft ends before assembly, ensuring screws are tightened evenly.
EWD couplings can be pre-assembled; disassembly involves specific procedures for releasing clamping rings.

Standards and Norms

Dimensions are according to DIN ISO 2768 cH; screws conform to ISO 4762 standards.

Recommendations

For exact torque transfer, high torsional stiffness is recommended.
Formulas for calculating required coupling torque and advice on selecting appropriate coupling size based on application needs are provided.

Key Parameters

Nominal torque, moment of inertia, torsional stiffness, and maximum speed are specified for different coupling sizes.
Permissible shaft displacement and spring rates are detailed.

Applications

Jaw couplings are suitable for various applications, including machine design, instrumentation, and control technology, offering features like electrical insulation and oscillation dampening.

Additional Notes

Guidelines for ensuring proper function include maintaining specific dimensions and considering operating factors like temperature and shock loading.

Overview

This document provides technical specifications for various types of miniature couplings, including elastomer, Oldham-type, and cardan-joint couplings.
Details material compositions, dimensions, performance parameters, and ordering information.

Specifications

Bellows are made of stainless steel, hubs of high tensile aluminium, and set screws conform to ISO 4029 standards.
Elastomer inserts are polyurethane, available in different hardness levels (blue and red).
Dimensions are provided according to DIN ISO 2768 cH standards, with specific measurements for each coupling type.

Performance Parameters

Nominal torque, moment of inertia, torsional stiffness, maximum speed, and shaft displacement are specified for each coupling type.
Temperature ranges and corrections for nominal torque are also provided.

Procedures

Ordering examples are given for specific coupling models with designated bore sizes.
Temperature corrections are specified for different temperature ranges.

Standards and Norms

Dimensions and material standards are aligned with DIN ISO 2768 cH and ISO 4029/4762.

Recommendations

Further bore sizes are available upon request, indicating customization options.
Temperature corrections should be applied to ensure optimal performance.

Key Data from Tables