Description
EP-NRV-E090 — Shaft-Input Aluminium Worm Gearbox with Tail Output Shaft

Technical Specifications — EP-NRV-E090

| Parameter | Value |
|---|---|
| Series | NRV-E (Solid Shaft Input, No Flange, Worm-Direction Tail Output Shaft) |
| Centre Distance | 090 mm |
| Reduction Ratios | 5, 7.5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100 |
| Rated Input Power | Up to 5.5 kW |
| Output Speed Range | 14 to 280 r/min (at 1400 r/min input) |
| Max Output Torque | 7,306 N·m |
| Input Configuration | Solid shaft input (no IEC flange) + worm-direction tail output shaft |
| Input Shaft | Solid keyed shaft input |
| Tail Output Shaft | Worm-direction (co-axial with worm shaft, opposite end) |
| Housing Material | Die-cast aluminium alloy |
| Worm Wheel Material | Phosphor bronze |
| Worm Shaft Material | 20CrMnTi alloy steel, case hardened, precision ground |
| Output Bore Diameter | 35 mm H7 with keyway |
| Lubrication | ISO VG 220 gear oil (factory filled) |
| Mounting Positions | B3, B6, B7, B8, V5, V6 |
| Protection Class | IP54 |
| Ambient Temperature | -10°C to +40°C |
NRV-E090 Performance Table (5.5 kW / 1400 r/min)
| Ratio (i) | Output Speed (r/min) | Output Torque (N·m) | Service Factor (fs) |
|---|---|---|---|
| 7.5 | 187 | 2,785 | 1.9 |
| 10 | 140 | 3,065 | 1.5 |
| 15 | 93 | 3,882 | 1.2 |
| 20 | 70 | 4,273 | 1.1 |
| 25 | 56 | 4,603 | 1.1 |
| 30 | 47 | 4,891 | 1.2 |
| 40 | 35 | 5,383 | 1.5 |
| 50 | 28 | 5,799 | 1.4 |
| 60 | 23 | 6,163 | 1.2 |
| 80 | 18 | 6,783 | 1.1 |
| 100 | 14 | 7,306 | 0.9 |
✅ Core Features & Unique Benefits
🔗 Worm-Direction Tail Output Shaft — The Key Differentiator
The defining feature of the NRV-E090 is its additional tail output shaft that extends in the same direction as the worm shaft axis. This second output enables simultaneous drive of two independent loads from a single gearbox — a primary application drive via the main output bore and a secondary auxiliary drive (encoder, tachometer, small pump, or fan) via the tail shaft.
🍲 Mine-Safe Chain Drive + Safety Interlock
The NRV-E090 is purpose-built for instrumented mining conveyor chain drives where the solid shaft input handles engine or hydraulic motor chain pull and the tail shaft provides safety PLC rotation interlock signals.
◯ Same Torque as Standard NRV090
The NRV-E090 delivers identical maximum output torque (7,306 N·m) to the standard NRV090, confirming that the tail shaft adds zero performance penalty on the main output. The tail shaft is driven directly off the worm shaft end, not the output stage.
🅆 Encoder & Feedback Ready
The tail output shaft provides a direct connection point for rotary encoders, tachogenerators, and pulse generators that monitor worm shaft speed in closed-loop motion control systems, eliminating external encoder brackets and coupling hardware.
🚫 IP54 — Dual-Seal Integrity
Both the main output bore and the tail shaft exit are sealed with dual-contact lip seals, maintaining IP54 protection across all mounting orientations without oil weeping at either shaft interface.

🏭 Application Scenarios
💧 Sludge Thickener Rotation Monitoring
Heavy industrial NMRV-E090 worm gearbox for municipal sludge thickeners where the tail shaft provides continuous rotation confirmation to the SCADA system, alerting operators instantly to rake stall events.
⚙ Chemical Reactor Feedback Drive
High-torque worm gear reducer with tail output shaft for chemical reactor agitator drives where the tail shaft encoder monitors worm shaft speed and feeds back to a process control system.
🍲 Mining Conveyor Instrumentation
Aluminium worm gearbox with tail shaft for underground mining conveyor take-up drives where the tail-mounted tachometer provides belt-speed data to the mine-wide monitoring and safety system.
📥 Port Conveyor Supervision
Corrosion-resistant worm gearmotor with tail shaft for port bulk material conveyor drives where the tail shaft speed signal confirms conveyor motion to the port operations control room.

🔎 Selection Guide
Worked Example — Mine Safety Interlock
Required: NRV-E090 at i=60, chain-driven from 5.5 kW engine at 1400 r/min, tail shaft to mine safety PLC. Output speed = 23 r/min, torque = 6,163 N·m. Tail shaft: safety encoder, 35 mm bore. ✅ NRV-E090-60 selected.
⚖ NRV-E090 vs Standard NRV090
| Feature | EP-NRV-E090 (with Tail Shaft) | EP-NRV090 (Standard) |
|---|---|---|
| Tail Output Shaft | ✅ Yes — worm-direction | No |
| Encoder / Feedback Mounting | Direct on tail shaft | Requires external bracket |
| Dual-Load Drive | Yes — main + tail | No — single output only |
| Main Output Torque | 7,306 N·m | 7,306 N·m |
| Housing Dimensions | Slightly longer (tail shaft protrusion) | Standard length |
| Shaft Input | Yes — solid keyed shaft | Yes — solid keyed shaft |
NRV-E090 Main Output Shaft Dimensions
| G1 (mm) | K1 (mm) | L/DZ (mm) | L1/SZ (mm) | b2 (mm) | d h6 (mm) | Keyway |
|---|---|---|---|---|---|---|
| 140 | 154 | 234 | 309 | 10 | 35 | M12 |

❓ Frequently Asked Questions
What is the tail output shaft on the EP-NRV-E090 and how is it different from the main output?
The tail shaft on the NRV-E090 exits the housing in the worm-direction axis (opposite end of the worm shaft), while the main output bore is perpendicular (90 degrees) to the worm axis. The tail shaft is driven off the worm shaft end and is used for encoder mounting, tachometer connection, or light auxiliary drive, while the main output delivers the full 7,306 N·m load torque.
Does the tail shaft reduce the main output torque of the NRV-E090?
No. The tail shaft draws only the small torque needed for its connected device. The main output retains the full 7,306 N·m rating, identical to the standard NRV090.
What is the input shaft specification for the NRV-E090?
The NRV-E090 has a solid keyed input shaft (no IEC flange). The shaft diameter matches the equivalent NMRV090 bore input diameter. It accepts chain sprockets, belt pulleys, and rigid couplings. A bilateral (double-ended) input shaft is standard; single-end configuration available on request.
What encoder types can be mounted on the NRV-E090 tail shaft?
Any standard keyed rotary encoder with the matching bore diameter can be mounted on the NRV-E090 tail shaft: incremental (5V–24V, 100–10,000 PPR), SSI absolute, or resolver-type. Confirm the encoder bore size and keyway before ordering. The tail shaft key dimensions match the catalogue DZ shaft specification for NMRV-E090.
Can the NRV-E090 be used for closed-loop speed control in a chain-driven system?
Yes. The NRV-E090 is the ideal solution for chain-driven systems requiring closed-loop speed feedback. The chain drives the solid input shaft; the main output drives the load; and the tail shaft mounts an encoder that feeds speed/position data back to the controller. This eliminates the need for a separate encoder mounting bracket or a second independent encoder drive arrangement.
⭐ Customer Reviews
★★★★★
“Our underground mine conveyor NRV-E090 units have tail-shaft rotation sensors integrated into our mine safety PLC. The sensors provide emergency-stop interlock signals when belt motion is lost. Exactly the safety integration we needed for underground compliance.”
Steve K. — Mining Engineer, Coal Mine 🇦🇺 Australia (NSW)
★★★★★
“The NRV-E090 drives our wastewater sludge scraper chain mechanism and the tail shaft pulse counter integrates into our SCADA for remote monitoring. Three years of continuous operation in hydrogen-sulphide atmosphere without corrosion or seal issues.”
Anita R. — Plant Manager, Water Authority 🇮🇿 New Zealand
★★★★☆
“We chain-drive NRV-E090 units on our quarry aggregate conveyor and use the tail-shaft tachometers for belt speed monitoring in our conveyor control system. The belt management system has reduced conveyor-related stoppages by 35% since installation.”
Rob C. — Operations Director, Aggregate Quarry 🇫🇯 Finland
⚙ Accessories & Compatible Products
⚡ IEC Motors (B5/B14)
Standard AC motors with matching IEC flange. VFD inverter-duty versions available for variable-speed control.
🔗 Output Shaft Kits
Single solid (DZ), double-ended (SZ), output flange (F), hollow flange (FL) — all H7/h6 tolerance with standard keyways.
🔨 Torque Arms & Brackets
Steel torque reaction arms for shaft-mount configurations; foot-mounting plates for B3/B6 orientations.
🔒 Seal & Breather Kits
Replacement lip-seal kits, vented breather plugs, and magnetic drain plugs for extended service intervals.

Request a Quote for EP-NRV-E090
Our engineering team will confirm the input shaft, ratio, and safety encoder specification for your chain-driven mining or industrial instrumented drive.
The EP-NRV-E090 aluminium worm gearbox combines a solid shaft input (no IEC flange) with an additional worm-direction tail output shaft. Centre distance 090 mm, ratios 5 to 100, input power up to 5.5 kW, max output torque 7,306 N·m. The tail shaft enables simultaneous encoder feedback, safety interlock monitoring, or auxiliary drive — the ideal instrumented shaft-input worm gearbox for chain-driven closed-loop agricultural, industrial, and mining drive systems.

