Description
GT2 GT Type Sleeve Coupling – 16–22mm Bore Rigid Muff Coupling for Zero-Backlash Shaft Connection
The GT2 GT type sleeve coupling — also known as a muff coupling — is the simplest and most direct form of rigid shaft coupling: a single cylindrical steel body with a through bore machined to receive two co-linear shaft ends, transmitting torque through keyway and fitted key engagement on each shaft side. At 55 mm outer diameter and 107 mm overall length, the GT2 provides a compact, maintenance-free rigid connection for 16–22 mm shaft diameters, rated at 63 N·m nominal torque at up to 9500 rpm maximum speed. The GT2 steps up to the 16–22 mm bore class covering the most common small servo and stepper motor output shaft diameters. Its 9500 rpm maximum speed and 63 N·m rated torque serve printing machine, packaging equipment, and laboratory automation drive connections where simplicity and zero backlash are equally valued.
The operating principle of the GT sleeve coupling is direct and reliable. Each shaft end is inserted into one half of the sleeve bore. A fitted key is placed in the matching keyways of both the shaft and the sleeve bore on each side — two keys total, typically positioned 180° apart. When the coupling rotates, torque is transmitted from the driving shaft to the sleeve through key-keyway bearing contact, and from the sleeve to the driven shaft through the same mechanism on the opposite side. There are no flexible elements, no preloaded fasteners to maintain, and no wear surfaces subject to degradation under normal operating conditions. The result is a permanent, zero-backlash connection that requires essentially no maintenance throughout its service life, provided the connected shafts remain accurately aligned.
The H7 bore tolerance and GB3852-1997 keyway standard ensure dimensional compatibility with standard motor and driven equipment shaft ends throughout the GT series. For special shaft configurations — non-standard diameters, tapered bores, or hydraulic fit bores — custom machining is available. The complete GT series, from GT1 through GT10, is listed on our product catalog page.
Technical Specifications
| Parameter | Value |
|---|---|
| Model | GT2 |
| Type | GT Type Sleeve Coupling (Muff Coupling) |
| Bore Range (d) | 16–22 mm |
| Outer Diameter (D) | 55 mm |
| Overall Length (L) | 107 mm |
| Nominal Torque (Tn) | 63 N·m |
| Maximum Speed [n] | 9500 rpm |
| Bore Tolerance | H7 standard |
| Keyway Standard | GB3852-1997 |
| Mass | 1.1 kg |
Dimension Reference
Construction and Functional Features
The GT2 body is machined from high-quality cast iron or cast steel — material selection dependent on model size and rated torque. The bore is machined to H7 tolerance to provide a controlled fit against the shaft end, complementing the key-keyway torque transmission with a stable radial contact between shaft and bore. The outer diameter is machined concentric with the bore to ensure rotational balance. Keyway slots are machined to GB3852-1997 standard dimensions for the specified bore size — verifying compatibility with standard motor shaft keyways without modification.
Zero Backlash
Rigid key-keyway torque transmission with no play or compliance — every angular increment on the driving shaft is replicated exactly on the driven shaft. Essential for phase-critical and encoder feedback applications.
Maintenance-Free Service Life
No wear elements, no elastomeric components to degrade, no bolts to retorque. Once correctly installed on aligned shafts, the GT sleeve coupling requires no maintenance throughout its service life.
Compact One-Piece Design
Single cylindrical body — no bolted flanges, no split halves, no external fasteners. Lowest-profile rigid coupling available for co-linear shaft connections, minimising guard size and axial space requirements.
Standard Keyway Compatibility
Bore and keyway dimensions to GB3852-1997 and H7 bore tolerance ensure direct compatibility with standard motor and driven equipment shaft ends throughout the industrial motor range.
Manufacturing Quality
Typical Applications
- Conveyor drive head shaft connections — sustained torque, continuous duty, minimal maintenance
- Compressor motor shaft connections — direct motor to crankshaft coupling with zero torsional play
- Wood processing machinery shaft connections — saw arbor and feed roll rigid drive coupling
- Textile machinery main shaft connections — loom main drive and roller feed rigid coupling
For technical enquiries and volume supply information, visit our contact page.
Customer Reviews and Case Studies
★★★★★
United Kingdom — Printing Machine OEM
The GT2 sleeve coupling connects print roller drive shafts on our digital printing machines. The 63 N·m rated torque covers our maximum roller drive load with a comfortable safety margin, and the 9,500 rpm capability supports our higher-speed print modes.
— Lead Engineer, Birmingham
★★★★★
South Korea — Food Conveyor Equipment
Installed on food conveyor drive shaft connections in our production line. The GT2 rigid sleeve provides the zero-backlash transmission needed for our indexing conveyor, ensuring consistent product spacing.
— Equipment Engineer, Busan
★★★★☆
Canada — Pharmaceutical Equipment
Used on tablet counting machine drive connections. The one-piece steel body meets our material specification for drive components in the production zone, and the absence of elastomeric elements simplifies our equipment validation process.
— Validation Engineer, Toronto
Frequently Asked Questions
What material is the GT sleeve coupling body manufactured from?
The standard GT sleeve coupling body is manufactured from cast iron (HT200) or cast steel (ZG45) depending on the model size and torque rating. Cast steel provides higher tensile strength and is used for larger models where the required wall section would be excessive in cast iron. For special material requirements, specify at enquiry.
What is the function of the keyway in a GT sleeve coupling?
The keyway in the sleeve bore engages with a fitted key that also sits in a matching keyway in the shaft surface. The key transmits the torque from shaft to sleeve (and vice versa) through bearing contact between the key side faces and the keyway walls. Two keys are required — one for each shaft end — positioned 180° apart for the Y-type standard configuration.
Can the GT sleeve coupling accommodate any shaft misalignment?
No. The GT sleeve coupling is a rigid coupling — it does not compensate for angular, parallel, or axial misalignment between the two connected shaft ends. Both shafts must be accurately aligned before the coupling is installed. Any residual misalignment will transmit bending moments to the shaft bearings, reducing bearing service life.
Is the GT sleeve coupling dynamically balanced as standard?
Standard GT sleeve couplings are not dynamically balanced as supplied. For high-speed applications approaching the maximum speed rating, dynamic balance can be provided on request. At lower operating speeds typical of most GT applications, inherent geometric balance of the machined cylinder is sufficient.
What is the safety factor recommendation for GT sleeve coupling selection?
A torque safety factor of 1.5 to 2.5 is recommended depending on the application’s load uniformity: 1.5 for uniform smooth loads (pumps, fans); 2.0 for moderate shock (compressors); 2.5 for high shock or reversal loads. Multiply the peak application torque by the safety factor before comparing to the coupling’s rated torque Tn.
Source the GT2 GT Sleeve Coupling
Ever Power manufactures the GT2 and the complete GT sleeve coupling series — GT1 through GT10, covering 12 mm to 200 mm bore — direct from our factory. Specify bore diameters, keyway requirements, and any non-standard dimensions for a prompt technical and commercial response.