Description
JQ-90 JQ Type Clamping Coupling – 90mm Split-Body Reactor Stirring Shaft Connection
The JQ-90 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 230 mm outer diameter and 330 mm overall length, the JQ-90 is sized for 90 mm shaft connections with a nominal torque rating of 5200 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 8–26 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-90 |
| Type | JQ Type Clamping Coupling (Split-Body) |
| Bore Diameter (dg H7) | 90 mm |
| Outer Diameter (D) | 230 mm |
| Overall Length (L) | 330 mm |
| Shaft Insertion Length (L1) | 38 mm |
| Hub Length (L2) | 146 mm |
| Body Length (L0) | 164 mm |
| Clamping Bolts (n–d0) | 8–26 |
| Nominal Torque (Tn) | 5200 N·m |
| Mass | 56.38 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-90’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 — 8–26 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 164 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
★★★★★
Germany — Large Reactor OEM
The JQ-90 is our standard connection on large-scale industrial reactor agitator drives where the shaft must be split for transport through facility access hatches. The clamp assembly is straightforward with two technicians and torque wrenches — no hydraulic tooling required.
— Senior Design Engineer, Dortmund
★★★★★
Malaysia — Petrochemical Plant
Installed on vertical gearbox to agitator shaft connections in our naphtha reforming unit. The JQ-90 handles continuous operation at elevated torque in a high-temperature process environment without any coupling maintenance between planned shutdowns.
— Plant Engineer, Kuala Lumpur
★★★★☆
New Zealand — Dairy Processing
Used on large-format cheese vat agitator drives. The clamp coupling meets our dairy hygiene requirements and the split design enables shaft removal for vat cleaning certification without affecting shaft alignment.
— Technical Manager, Auckland
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-90 JQ Clamping Coupling
Ever Power manufactures the JQ-90 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.
