Description
EP-NRV-E150 — Shaft-Input Aluminium Worm Gearbox with Tail Output Shaft

Technical Specifications — EP-NRV-E150

| Parameter | Value |
|---|---|
| Series | NRV-E (Solid Shaft Input, No Flange, Worm-Direction Tail Output Shaft) |
| Centre Distance | 150 mm |
| Reduction Ratios | 5, 7.5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100 |
| Rated Input Power | Up to 15 kW |
| Output Speed Range | 14 to 280 r/min (at 1400 r/min input) |
| Max Output Torque | 16,508 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 | 50 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-E150 Performance Table (15 kW / 1400 r/min)
| Ratio (i) | Output Speed (r/min) | Output Torque (N·m) | Service Factor (fs) |
|---|---|---|---|
| 7.5 | 187 | 6,962 | 1.7 |
| 10 | 140 | 7,663 | 1.3 |
| 15 | 93 | 8,771 | 0.9 |
| 20 | 70 | 9,654 | 1.0 |
| 25 | 56 | 10,400 | 0.8 |
| 30 | 47 | 11,051 | 1.3 |
| 40 | 35 | 12,163 | 1.3 |
| 50 | 28 | 13,103 | 1.0 |
| 60 | 23 | 13,924 | 0.8 |
| 80 | 18 | 15,325 | 1.0 |
| 100 | 14 | 16,508 | 0.8 |
✅ Core Features & Unique Benefits
🔗 Worm-Direction Tail Output Shaft — The Key Differentiator
The defining feature of the NRV-E150 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.
★ 15 kW Chain + Maximum Encoder Output
The NRV-E150 is the flagship shaft-input worm gearbox with tail shaft, accepting 15 kW chain or belt input while providing the highest radial load capacity (18,000 N) and tail shaft output in the NRV-E series.
◯ Same Torque as Standard NRV150
The NRV-E150 delivers identical maximum output torque (16,508 N·m) to the standard NRV150, 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
🚢 Port Crane Hoist with Encoder
Flagship NMRV-E150 worm gearbox for heavy port crane hoist chain drives where the tail shaft mounts a high-resolution encoder providing precise hoist position feedback to the crane management system.
📥 Bulk Conveyor SCADA Monitoring
Maximum-torque worm gear reducer with tail output shaft for bulk material handling conveyor head-end drives where the tail shaft speed signal monitors tonnage throughput in real time.
⚙ Large Chemical Plant DCS Integration
Flagship aluminium worm gearbox with tail shaft for large polymer reactor agitator drives where the tail encoder feeds into the plant DCS providing real-time agitator speed verification.
💧 Primary Treatment Monitoring
NMRV-E150 worm gearbox for large-diameter primary clarifier rake drives where the tail shaft pulse counter provides the water authority operations centre with continuous rake-rotation confirmation.

🔎 Selection Guide
Worked Example — Port Throughput Tracking
Required: NRV-E150 at i=80, chain-driven from 15 kW diesel engine, tail shaft to tonnage tracking encoder. Output speed = 18 r/min, torque = 15,325 N·m. Tail shaft: 360 PPR pulse encoder, 50 mm bore. ✅ NRV-E150-80 selected.
⚖ NRV-E150 vs Standard NRV150
| Feature | EP-NRV-E150 (with Tail Shaft) | EP-NRV150 (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 | 16,508 N·m | 16,508 N·m |
| Housing Dimensions | Slightly longer (tail shaft protrusion) | Standard length |
| Shaft Input | Yes — solid keyed shaft | Yes — solid keyed shaft |
NRV-E150 Main Output Shaft Dimensions
| G1 (mm) | K1 (mm) | L/DZ (mm) | L1/SZ (mm) | b2 (mm) | d h6 (mm) | Keyway |
|---|---|---|---|---|---|---|
| 200 | 187 | 297 | 374 | 14 | 50 | M16 |

❓ Frequently Asked Questions
What is the tail output shaft on the EP-NRV-E150 and how is it different from the main output?
The tail shaft on the NRV-E150 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 16,508 N·m load torque.
Does the tail shaft reduce the main output torque of the NRV-E150?
No. The tail shaft draws only the small torque needed for its connected device. The main output retains the full 16,508 N·m rating, identical to the standard NRV150.
What is the input shaft specification for the NRV-E150?
The NRV-E150 has a solid keyed input shaft (no IEC flange). The shaft diameter matches the equivalent NMRV150 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-E150 tail shaft?
Any standard keyed rotary encoder with the matching bore diameter can be mounted on the NRV-E150 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-E150.
Can the NRV-E150 be used for closed-loop speed control in a chain-driven system?
Yes. The NRV-E150 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 port grain conveyor head-end uses NRV-E150 chain-driven from our central diesel engine. The tail-shaft high-resolution encoder feeds our terminal tonnage tracking system with belt-speed data for automatic throughput calculation. Extremely reliable after 16 months.”
Tony V. — Terminal Engineer, Grain Export Port 🇦🇺 Australia (WA)
★★★★★
“We use four NRV-E150 units on our offshore crane hoist chain drives. The tail-shaft encoders provide hoist position feedback to our crane management system. The stainless shaft option eliminated corrosion that affected our previous cast-iron reducer encoders within 12 months.”
Anders L. — Mechanical Engineer, Offshore Platform 🇳🇴 Norway
★★★★☆
“The NRV-E150 drives our primary clarifier rake chain via diesel engine. The tail-shaft pulse counter confirms rake rotation to our water authority SCADA and automatically triggers a maintenance alert if rake speed drops below the design value.”
Sarah M. — Water Infrastructure Engineer, City Authority 🇦🇺 Australia (QLD)
⚙ 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.

Enquire About EP-NRV-E150
The NRV-E150 is our flagship shaft-input instrumented worm gearbox. Our engineers will confirm the chain drive specification, radial load, and encoder bore for your application.
The EP-NRV-E150 aluminium worm gearbox combines a solid shaft input (no IEC flange) with an additional worm-direction tail output shaft. Centre distance 150 mm, ratios 5 to 100, input power up to 15 kW, max output torque 16,508 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.

