Description
EP-NRV-E075 — Shaft-Input Aluminium Worm Gearbox with Tail Output Shaft

Technical Specifications — EP-NRV-E075

| Parameter | Value |
|---|---|
| Series | NRV-E (Solid Shaft Input, No Flange, Worm-Direction Tail Output Shaft) |
| Centre Distance | 075 mm |
| Reduction Ratios | 5, 7.5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100 |
| Rated Input Power | Up to 4.0 kW |
| Output Speed Range | 14 to 280 r/min (at 1400 r/min input) |
| Max Output Torque | 6,603 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-E075 Performance Table (4.0 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 | 3,509 | 1.1 |
| 20 | 70 | 3,882 | 1.1 |
| 25 | 56 | 4,273 | 1.0 |
| 30 | 47 | 4,421 | 1.0 |
| 40 | 35 | 4,865 | 1.5 |
| 50 | 28 | 5,241 | 1.2 |
| 60 | 23 | 5,569 | 1.0 |
| 80 | 18 | 5,799 | 1.9 |
| 100 | 14 | 6,603 | 1.9 |
✅ Core Features & Unique Benefits
🔗 Worm-Direction Tail Output Shaft — The Key Differentiator
The defining feature of the NRV-E075 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.
🌿 Heavy Chain + SCADA Integration
At 4.0 kW chain input, the NRV-E075 is the standard choice for heavily loaded agricultural chain drives requiring SCADA rotation monitoring — jam detection, bin-fill monitoring, and throughput tracking.
◯ Same Torque as Standard NRV075
The NRV-E075 delivers identical maximum output torque (6,603 N·m) to the standard NRV075, 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
🌿 Heavy Agricultural Monitoring
High-torque NMRV-E075 worm gearbox for heavy auger and elevator drives where the tail shaft mounts a rotation sensor confirming grain flow in real time and triggering an alarm if the auger jams.
💧 Mixing Tank Level-Speed Control
Worm gear reducer with tail output shaft for industrial mixing tanks where a tail-shaft encoder feeds back to a variable-frequency controller, maintaining constant tip-speed regardless of fluid viscosity.
🏗 Construction Material Monitoring
Aluminium worm gearbox with tail shaft for concrete mixer and aggregate conveyor drives where the tail-shaft tachometer provides real-time rotation monitoring to the plant SCADA system.
⚙ Servo-Assisted Automation
NMRV-E075 worm gearbox tail shaft for servo-assisted positioning stages where the tail encoder provides position feedback in semi-closed loop control, reducing servo drive cost versus full servo gearbox solutions.

🔎 Selection Guide
Worked Example — Sugarcane Conveyor Monitoring
Required: NRV-E075 at i=40, chain-driven from 3.0 kW PTO countershaft, tail shaft to SCADA rotation sensor. Output speed = 35 r/min, torque = 4,865 N·m. Tail shaft: inductive proximity sensor target, 28 mm bore. ✅ NRV-E075-40 selected.
⚖ NRV-E075 vs Standard NRV075
| Feature | EP-NRV-E075 (with Tail Shaft) | EP-NRV075 (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 | 6,603 N·m | 6,603 N·m |
| Housing Dimensions | Slightly longer (tail shaft protrusion) | Standard length |
| Shaft Input | Yes — solid keyed shaft | Yes — solid keyed shaft |
NRV-E075 Main Output Shaft Dimensions
| G1 (mm) | K1 (mm) | L/DZ (mm) | L1/SZ (mm) | b2 (mm) | d h6 (mm) | Keyway |
|---|---|---|---|---|---|---|
| 120 | 123 | 192 | 247 | 8 | 28 | M10 |

❓ Frequently Asked Questions
What is the tail output shaft on the EP-NRV-E075 and how is it different from the main output?
The tail shaft on the NRV-E075 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 6,603 N·m load torque.
Does the tail shaft reduce the main output torque of the NRV-E075?
No. The tail shaft draws only the small torque needed for its connected device. The main output retains the full 6,603 N·m rating, identical to the standard NRV075.
What is the input shaft specification for the NRV-E075?
The NRV-E075 has a solid keyed input shaft (no IEC flange). The shaft diameter matches the equivalent NMRV075 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-E075 tail shaft?
Any standard keyed rotary encoder with the matching bore diameter can be mounted on the NRV-E075 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-E075.
Can the NRV-E075 be used for closed-loop speed control in a chain-driven system?
Yes. The NRV-E075 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 sugarcane conveyor chain drives use NRV-E075 units. The tail-shaft rotation sensors feed our plant SCADA and we receive instant alerts if any conveyor section stops during harvest. The system has prevented two costly conveyor pile-up incidents this season.”
Barry F. — Maintenance Manager, Sugarcane Farm 🇦🇺 Australia (QLD)
★★★★★
“We use the NRV-E075 on our mobile concrete plant chain drive with a tail-shaft tachometer monitoring drum speed for our batching computer. The combined chain-input encoder-output design eliminated a separate encoder mounting assembly on each plant.”
Carlos E. — Plant Manager, Civil Construction 🇨🇴 Colombia
★★★★☆
“Six NRV-E075 units drive our grain auger system via central shaft chain. The tail-shaft encoders provide bin-fill calculations based on auger speed and our grain inventory system is now automated. Excellent integration of mechanical and electrical functions.”
Ian M. — Operations Manager, Grain Storage 🇦🇺 Australia (SA)
⚙ 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.

Specify the EP-NRV-E075
Our team will confirm the input shaft, ratio, and SCADA sensor specification for your heavy chain-driven agricultural or industrial monitored drive.
The EP-NRV-E075 aluminium worm gearbox combines a solid shaft input (no IEC flange) with an additional worm-direction tail output shaft. Centre distance 075 mm, ratios 5 to 100, input power up to 4.0 kW, max output torque 6,603 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.


