Description
JQ-55 JQ Type Clamping Coupling – 55mm Split-Body Reactor Stirring Shaft Connection
The JQ-55 JQ type clamping coupling is a split-body rigid shaft connector engineered for reactor stirring shaft applications where the shaft is manufactured in two sections — either because the complete shaft length exceeds what can be handled as a single piece during installation, or because a vertical gearbox output shaft must be connected to the reactor agitator shaft with non-standard bore dimensions. At 135 mm outer diameter and 190 mm overall length, the JQ-55 is sized for 55 mm shaft connections with a nominal torque rating of 530 N·m, covering the full operating torque range of industrial agitator drives at this shaft size.
The JQ clamping coupling operates on the principle of split-body radial clamping: the coupling body is manufactured in two semi-cylindrical halves that wrap around the two shaft ends from the side and are drawn together by 6–14 clamping bolts. When the bolts are tightened to the specified torque, the bore halves compress against the shaft surfaces, generating a friction grip that transmits the rated torque without requiring any keyway or interference fit. This assembly method is particularly valuable in plant installations where shaft end access is restricted — above reactor vessels, between flanged connections, or in confined equipment rooms — because the coupling assembles laterally around the shaft rather than requiring axial shaft movement through the bore.
The ability to disassemble the coupling without shaft modification is a significant maintenance advantage. When the coupling bolts are released, the two body halves separate cleanly, leaving both shaft surfaces intact and undamaged for reuse. This is in contrast to interference-fit or keyed hub connections, which typically require heat, pressing, or shaft modification to disassemble. For the full range of clamping and rigid coupling models, visit our product catalog page.
Technical Specifications
| Parameter | Value |
|---|---|
| Model | JQ-55 |
| Type | JQ Type Clamping Coupling (Split-Body) |
| Bore Diameter (dg H7) | 55 mm |
| Outer Diameter (D) | 135 mm |
| Overall Length (L) | 190 mm |
| Shaft Insertion Length (L1) | 24 mm |
| Hub Length (L2) | 83 mm |
| Body Length (L0) | 94 mm |
| Clamping Bolts (n–d0) | 6–14 |
| Nominal Torque (Tn) | 530 N·m |
| Mass | 10.85 kg |
* Bore tolerance H7 standard; H8/j7 available. Non-standard bore sizes available on request — specify at order time.
Dimension Drawing
Split-Body Design and Operational Features
The JQ-55’s split-body construction is the defining functional feature of the JQ series. Each half of the coupling body contains one full bore semicircle, and the two halves are precision-machined to mate at the split plane with minimal gap when the clamping bolts are torqued. The bore surface is machined to H7 tolerance as standard, providing a controlled interference-adjacent fit against the shaft end for maximum friction grip area. The clamping bolt arrangement — 6–14 bolts distributed around the split flange — provides symmetric clamping force across the bore circumference, minimising the risk of shaft deflection or misalignment from uneven bolt loading.
Installation requires no special tooling beyond a calibrated torque wrench. The two shaft ends are brought into position, the coupling halves are placed around them, and the bolts are tightened progressively in a cross pattern until the specified bolt torque is achieved on all fasteners. The specified body length L0 of 94 mm accommodates the gap between shaft ends inside the coupling. For non-standard shaft configurations where the gap dimension is critical, custom body lengths can be specified — contact our technical team for assistance.
Manufacturing Quality
Keyless Shaft Connection
No keyway required in either shaft section. The friction clamp transmits the full rated torque through the bore contact surface, eliminating the keyway stress concentration that contributes to shaft fatigue in keyed hub designs.
Lateral Assembly
Assembles around the shaft from the side — no axial shaft movement required. Essential for installations in confined spaces, above reactor vessels, or between fixed-position flanges where end access is unavailable.
Non-Destructive Disassembly
Both shaft ends are released undamaged when the clamping bolts are loosened. Shafts can be reused across multiple coupling replacements — reducing lifecycle shaft cost and maintenance downtime.
Custom Bore Available
Non-standard bore diameters for vertical reducer output shafts can be specified at order time. Ever Power machines bores to the stated non-standard dimension, ensuring compatibility with custom gearbox output shafts without adapter sleeves.
Typical Applications
- Petrochemical agitator drives — polymerisation reactors and blending vessel connections
- Rubber and polymer processing — kneader and internal mixer shaft connections
- Mining reagent agitators — mineral flotation and leaching vessel mixing drives
- Pulp and paper production — digester and stock preparation agitator connections
Customer Reviews and Case Studies
★★★★★
United States — Industrial Mixing OEM
Our chemical mixing equipment line uses the JQ-55 on all 55 mm shaft configurations. The split clamp design eliminates the need for shaft-end access during installation, which is critical in our compact skid-mounted mixing units where end-access is limited.
— Lead Mechanical Engineer, Houston
★★★★★
Belgium — Detergent Production
Used on high-speed detergent mixing reactor drives. The JQ-55 has maintained its clamp torque across temperature cycles from 20°C to 80°C — important in our batch processing where reactor temperature varies throughout the process.
— Process Engineer, Ghent
★★★★☆
Indonesia — Palm Oil Processing
Fitted on palm oil clarification agitator drives. The JQ-55 handles the dense slurry loading reliably. Ease of disassembly during planned maintenance was the primary reason for selecting the clamp coupling over a traditional keyed flange.
— Plant Maintenance Engineer, Medan
Frequently Asked Questions
Can the JQ coupling be used for horizontal shaft connections?
Yes. While the JQ coupling is most commonly associated with vertical reactor stirring shaft applications, it is equally suitable for horizontal shaft connections wherever the split-body assembly feature is advantageous. The coupling transmits torque through clamping force regardless of shaft orientation.
What is the difference between d1 (H8/j7) and d (H7) bore specifications?
d1 (H8/j7) is the bore dimension for the shaft end entering from the side with a wider tolerance class, suitable for sliding shaft entry during installation. d is the bore specified to H7 tolerance for a tighter fit used in the flanged hub section. Refer to the dimension drawing for the specific bore locations.
Is the JQ coupling dynamically balanced?
Standard JQ couplings are not dynamically balanced as supplied. For high-speed applications approaching the maximum speed rating, dynamic balance correction can be provided on request. At lower operating speeds typical of reactor agitator applications, balance is not a significant concern.
What is the recommended gap between shaft ends inside the JQ coupling?
The shaft ends should not contact each other inside the coupling body. A minimum gap of 2–5 mm between shaft ends is recommended to prevent axial load transfer through the shaft ends, which could load the reactor bottom bearing adversely.
Can the JQ coupling be supplied with special surface treatments?
Yes. Hot-dip galvanising, zinc plating, or epoxy coating can be applied to the coupling body for environments with elevated corrosion risk. Specify the required treatment when submitting your enquiry.
Source the JQ-55 JQ Clamping Coupling
Ever Power manufactures the JQ-55 and the full JQ clamping coupling series direct from our factory. Specify your bore diameter, shaft configuration, and non-standard dimensions if required — our team will confirm suitability and provide factory-direct pricing.
