Description
EP-NRV075 — Shaft-Input High-Torque Aluminium Worm Gear Reducer
The EP-NRV075 is the shaft-input version of the NMRV75, sharing the same 75 mm centre distance, 6,603 N·m maximum output torque, and 4.0 kW input power rating in an identical die-cast aluminium housing, but configured with a solid keyed input shaft in place of the bore-input IEC flange. This configuration makes the NRV075 the natural choice when power arrives via chain sprocket, belt pulley, hydraulic motor output, or PTO-driven countershaft — driving arrangements that cannot present an IEC flange face to the gearbox. Compared with the NRV063 at 63 mm centre distance, the NRV075 delivers 18% more output torque, enabling it to handle heavier chain-driven loads while maintaining the NRV series’s lightweight aluminium housing and corrosion-resistant finish. In Australian industry, the NRV075 is particularly valued for heavy agricultural chain-driven conveyor systems and hydraulic-motor-driven industrial mixing and processing equipment, where the solid shaft input integrates naturally into existing chain or belt drive train layouts without requiring an IEC motor adaptor or modifying the drive geometry.
Technical Specifications — EP-NRV075
| Parameter | Value |
|---|---|
| Series | NRV (Solid Shaft Input, No Input Flange) |
| Centre Distance | 75 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 Type | Solid shaft input, no IEC flange |
| Housing Material | Die-cast aluminium alloy |
| Worm Wheel Material | Phosphor bronze |
| Worm Shaft Material | 20CrMnTi alloy steel, case hardened, precision ground |
| Equivalent NMRV | NMRV75 (same internal assembly) |
| Output Bore Diameter | 35 mm standard (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 |
NRV075 Performance Table (4.0 kW / 1400 r/min)
| Ratio (i) | Output Speed (r/min) | Output Torque (N·m) | Fr max Input (N) | 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 | 7,380 | 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 |
✅ NRV075 Key Advantages
🔗 Hydraulic Motor & PTO Compatibility
The NRV075 solid input shaft directly accepts a hydraulic motor output via a rigid or flexible coupling, making it the standard choice for hydraulic-powered agricultural and construction equipment where flow-rate speed control replaces VFD motor drives.
📈 6,603 N·m at 4.0 kW
Identical to the NMRV075, the NRV075 delivers 6,603 N·m at ratio 100, handling the largest heavy-chain conveyor and mixing loads in the 4.0 kW shaft-input category.
◯ 35 mm Output Bore — Heavy-Shaft Interface
The 35 mm H7 hollow output bore and DZ solid shaft match the shaft diameters of heavy-duty chain sprockets and agitator hubs in the 3.0–4.0 kW power range.
⛁ Corrosion-Free for Outdoor Machinery
Aluminium housing with electrostatic paint performs in North Queensland’s tropical humidity, the UV exposure of Western Australian grain farms, and the salt-spray of coastal Australian industrial and port environments.
🌞 Passive Thermal Stability at 4 kW
The deeply finned NRV075 housing manages heat generation at 4 kW continuous chain-drive input passively, without requiring auxiliary cooling fans that add complexity to shaft-driven machinery.
🏭 Application Sectors
🌿 Heavy Agricultural Conveyors
High-torque shaft-input worm gear reducer for steep-incline grain elevators, heavy auger chain drives, and sugarcane conveyor systems driven by PTO or engine countershafts on Australian farms in Queensland, Western Australia, and New South Wales.
💧 Hydraulic-Motor-Driven Mixing
Compact NRV worm gearbox for hydraulic-motor-driven mixer agitators in mobile concrete plants, slurry mixing trailers, and fertiliser blending equipment where hydraulic flow controls speed.
🏗 Construction & Earthmoving Equipment
Shaft-input worm gear reduction gearbox for concrete mixer drum drives, earthmoving machine conveyor drives, and road-marking machine material feed drives powered by on-board engines.
⚙ Automation & Line-Shaft Drives
Aluminium worm gearmotor alternative for automated production lines where a central chain-driven line shaft supplies power to multiple driven stations at different speeds via individual NRV075 gearboxes at each station.
🔎 NRV075 Selection Guide
Design Example — Heavy Grain Elevator Chain Drive
Required: chain drive from a 3.0 kW engine at 1400 r/min driving a grain elevator at 28 r/min. i = 1400/28 = 50. Output torque at i=50 = 5,241 N·m. For medium-shock load fs=1.25: demand = 5,241/1.25 = 4,193 N·m — within rating. ✅ NRV075-50 selected.
NRV075 vs NMRV075 — Which Series to Choose
| Feature | EP-NRV075 (Shaft Input) | EP-NMRV075 (Flange Input) |
|---|---|---|
| Input Configuration | Solid keyed shaft | Bore input with IEC flange |
| Best Drive Source | Chain, belt, coupling, hydraulic motor, PTO | Direct IEC face-mount motor |
| IEC Flange | Not applicable | Multiple B5/B14 sizes |
| Output Torque | Identical | Identical |
| Housing Dimensions | Identical | Identical |
| Self-Lock at i≥30 | Yes | Yes |
| Best For | Remote or non-standard drive sources | Standard motor-integrated assemblies |
NRV075 DZ/SZ Output Shaft Dimensions
| G1 (mm) | K1 (mm) | L/DZ (mm) | L1/SZ (mm) | b2 (mm) | d h6 (mm) | Keyway |
|---|---|---|---|---|---|---|
| 120 | 123.5 | 192 | 247 | 8 | 28 | M10 |
❓ FAQs — EP-NRV075
What is the maximum input shaft radial load for the NRV075?
The Fr max for the NRV075 input shaft is 7,380 N at mid-shaft for ratio 30 operations. For heavy chain drives, calculate the resultant chain tension and confirm it stays below this limit. Using a larger sprocket reduces chain tension for the same power transmitted.
Can the NRV075 be driven by a hydraulic motor?
Yes. The NRV075 solid keyed input shaft accepts a hydraulic motor shaft via a rigid coupling. Provide the hydraulic motor’s shaft diameter and key dimensions when ordering; we will confirm compatibility and supply a matching coupling or adaptor if required.
How does the NRV075 handle start-up shock loads from engine-driven equipment?
For engine or PTO-driven applications with cold-start shock, select a ratio whose rated torque at full power divided by the service factor (fs=1.5–2.0 for heavy shock) exceeds the peak start-up torque. The phosphor-bronze worm wheel absorbs short-duration shock torque through plastic deformation of asperities without catastrophic failure.
Is the NRV075 output bore suitable for direct sprocket mounting?
Yes. The 35 mm H7 hollow bore accepts a driven shaft directly. For sprocket-on-shaft configurations, ensure the driven shaft is 35 mm h6 or j6 tolerance for an appropriate fit class. Use the DZ solid shaft option when a coupling connection rather than a shaft-mount arrangement is required.
Does the NRV075 require the same oil volume as the NMRV075?
Yes. The NRV075 uses the same housing casting as the NMRV075, so the oil fill volume per mounting position is identical. Refer to the mounting-position oil-level diagram supplied with the unit for the correct fill height in each of the six positions.
⭐ Customer Reviews
★★★★★
“We upgraded our sugarcane conveyor chain drives to NRV075 units at i=40. The 4.0 kW chain input handles our peak loading without issue and the aluminium housing has survived two full cane harvest seasons in Far North Queensland’s heat and humidity without any corrosion.”
Barry F. — Maintenance Manager, Sugarcane Farm 🇦🇺 Australia (Queensland)
★★★★★
“Our mobile concrete mixing plant uses an NRV075 with a hydraulic motor input. The direct shaft coupling is simple and reliable — we’ve run 1,500 hours across multiple remote construction sites with no maintenance required.”
Carlos E. — Plant Manager, Civil Construction Contractor 🇨🇴 Colombia
★★★★☆
“Six NRV075 units drive our central-line-shaft-fed grain auger system. The solid input shaft made chain installation straightforward and the 6,603 N·m torque rating gives a comfortable safety margin on our heaviest grain variety.”
Ian M. — Operations Manager, Grain Storage Facility 🇦🇺 Australia (South Australia)
⚙ Accessories & Compatible Products
⚡ IEC Motors (B5/B14)
Standard single-phase and three-phase AC motors with matching IEC flange. VFD inverter-duty versions available.
🔗 Output Shaft Kits
Single solid (DZ), double-ended (SZ), output flange (F), hollow flange (FL) — all H7/h6 tolerance with standard keyways.
🔨 Torque Arms
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.
Order the EP-NRV075 Today
Our team will confirm the input shaft key dimensions, ratio, and output configuration for your chain, belt, or hydraulic motor drive. OEM volume pricing available on request.
The EP-NRV075 aluminium worm gear reducer has a 75 mm centre distance, ratios from 5 to 100, rated input power up to 4.0 kW, and maximum output torque of 6,603 N·m. Its solid shaft input connects directly to chain, belt, or hydraulic motor drives without an IEC flange, making it the preferred high-torque shaft-input worm gearbox for heavy agricultural machinery, large mixing tanks, and construction material handling equipment across Australia.
