Описание
Double Stage NMRV Worm Gearbox — Ultra-High Ratio Two-Stage Worm Drive Reducer up to 6,000:1
The EP Double Stage NMRV Worm Gearbox achieves gear ratios that no single-stage compact worm reducer can approach — from approximately 100:1 up to 6,000:1 — by combining two NMRV aluminum worm reducers in series. Where a single NMRV stage maxes out at 100:1, two stages multiplied together produce ratios of 900:1, 1,800:1, 3,600:1, or higher, enabling standard four-pole motors to drive output shafts at fractional-rpm speeds without the complexity, cost, or size of a purpose-built high-ratio helical gearbox or variable-speed drive.
The double stage configuration is inherently compact: the first-stage NMRV (smaller, higher-speed unit) mounts directly against the second-stage NMRV (larger, higher-torque unit) using a standard intermediate shaft connection. The overall housing remains much smaller and lighter than any equivalent single-stage unit capable of the same ratio. With nine standard combinations from NMRV025+030 to NMRV063+130, Ever Power offers a wide range of output torque and shaft size options to match the requirements of slow-speed conveyor positioning drives, solar panel tracking mechanisms, antenna positioning systems, precision industrial automation, and any application requiring sub-1 rpm output from a standard motor.
How the Double Stage NMRV Works
Each NMRV stage is a standard right-angle worm reducer. In the double stage configuration, the output shaft of the first (input) stage is connected via an intermediate coupling or direct stub shaft to the input of the second (output) stage. The overall gear ratio is the product of the two individual stage ratios — for example, combining a 30:1 first stage with a 60:1 second stage produces an overall ratio of 1,800:1. Overall efficiency is the product of both stage efficiencies — typically 35–55% for a double worm drive, meaning motor power must be sized accordingly.
Standard Double Stage NMRV Combinations
| Combination | 1st Stage (Input) | 2nd Stage (Output) | Overall Ratio Range | Output Shaft dia. | Approx. Weight |
|---|---|---|---|---|---|
| NMRV025 + NMRV030 | NMRV025 (5–60:1) | NMRV030 (5–60:1) | 25:1 – 3,600:1 | 14 mm H8 | 1.6 kg |
| NMRV025 + NMRV040 | NMRV025 (5–60:1) | NMRV040 (5–60:1) | 25:1 – 3,600:1 | 18 mm H8 | 2.6 kg |
| NMRV030 + NMRV040 | NMRV030 (5–60:1) | NMRV040 (5–60:1) | 25:1 – 3,600:1 | 18 mm H8 | 3.2 kg |
| NMRV030 + NMRV050 | NMRV030 (5–60:1) | NMRV050 (5–100:1) | 25:1 – 6,000:1 | 25 mm H8 | 4.6 kg |
| NMRV030 + NMRV063 | NMRV030 (5–60:1) | NMRV063 (7.5–100:1) | 37.5:1 – 6,000:1 | 30 mm H8 | 7.3 kg |
| NMRV040 + NMRV075 | NMRV040 (5–60:1) | NMRV075 (7.5–100:1) | 37.5:1 – 6,000:1 | 35 mm H8 | 11.4 kg |
| NMRV040 + NMRV090 | NMRV040 (5–60:1) | NMRV090 (7.5–100:1) | 37.5:1 – 6,000:1 | 35 mm H8 | 15.1 kg |
| NMRV050 + NMRV110 | NMRV050 (5–100:1) | NMRV110 (7.5–100:1) | 37.5:1 – 10,000:1 | 42 mm H8 | 38.5 kg |
| NMRV063 + NMRV130 | NMRV063 (7.5–100:1) | NMRV130 (7.5–100:1) | 56:1 – 10,000:1 | 45 mm H8 | 54.2 kg |
Typical Overall Gear Ratios by Stage Combination
| 1st Stage Ratio | 2nd Stage Ratio | Overall Ratio | Output Speed (at 1400 rpm input) |
|---|---|---|---|
| 5:1 | 5:1 | 25:1 | 56.0 rpm |
| 10:1 | 10:1 | 100:1 | 14.0 rpm |
| 20:1 | 20:1 | 400:1 | 3.5 rpm |
| 30:1 | 30:1 | 900:1 | 1.56 rpm |
| 40:1 | 40:1 | 1,600:1 | 0.875 rpm |
| 50:1 | 50:1 | 2,500:1 | 0.56 rpm |
| 60:1 | 60:1 | 3,600:1 | 0.39 rpm |
| 80:1 | 80:1 | 6,400:1 | 0.22 rpm |
| 100:1 | 100:1 | 10,000:1 | 0.14 rpm |
Technical Specifications — General Double Stage Parameters
| Parameter | Value |
|---|---|
| Overall Gear Ratio Range | ~25:1 to 10,000:1 (combination dependent) |
| Typical Working Ratio Range | 100:1 to 6,000:1 (most common applications) |
| Overall Efficiency | 35–55% (two-stage worm drive) |
| Output Shaft Options | 14 / 18 / 25 / 30 / 35 / 42 / 45 mm H8 (combination dependent) |
| Housing Material | Die-cast aluminum alloy (both stages) |
| Worm Wheel Material | Phosphor bronze (sand-cast; centrifugally cast for NMRV130 output stage) |
| Motor Input | IEC and NEMA flanges (per output stage NMRV model) |
| Mounting | Foot-mount (NMRV base) on output stage; input stage suspended |
| Protection Class | IP54 standard |
| Lubrication | ISO VG 220 worm gear oil (each stage filled separately) |
| Operating Temperature | -10 to +40 deg C ambient |
Core Features & Engineering Advantages
⚙ Ratios to 10,000:1 in Compact Aluminum Housing
By combining two standard NMRV units, the double stage configuration delivers ratios that would otherwise require a purpose-built, significantly more expensive high-ratio helical or cycloidal gearbox. The all-aluminum housing keeps total weight well below comparable steel-housing alternatives.
🔥 Sub-1 RPM Output from Standard Motors
At 3,600:1 (two 60:1 stages), a standard 4-pole 1,400 rpm motor produces just 0.39 rpm output — enabling precision slow-speed rotation drives without inverters, variable-frequency drives, or special low-speed motors in Australian solar tracking, conveyor positioning, and antenna drive applications.
📈 Nine Standard Combinations — Nine Output Shaft Sizes
From 14 mm (NMRV030 output stage) to 45 mm (NMRV130 output stage), the nine standard combinations provide a complete range of output shaft diameters covering compact light automation drives through to heavy industrial slow-speed conveyor positioning.
📝 Self-Locking at High Ratios
Both stages of a double stage NMRV are inherently self-locking at ratios of 30:1 and above. In a double stage unit, even a single low-ratio first stage combined with a self-locking second stage provides a non-back-driveable output — eliminating load-holding brakes on solar tracker, gate actuator, and antenna positioning drives.
🌞 Flexible Output Shaft Orientation
Because each stage is a right-angle worm reducer, the double stage unit can be assembled with the output shaft parallel to, at 90 degrees to, or in other spatial orientations relative to the motor input, providing design flexibility that single-stage high-ratio reducers rarely offer in such compact dimensions.
Application Scenarios & Industry Suitability
☀
Solar Panel Tracking
Single-axis and dual-axis solar panel tracking systems — 900:1 to 3,600:1 ratios provide the extremely slow, precise angular movement required for solar tracking drives in Australian utility-scale solar farms and rooftop commercial installations.
⒑
Slow-Speed Conveyor Positioning
Precision slow-speed conveyor indexing drives, transfer car positioning drives, and automated warehouse conveyor divert drives — sub-1 rpm output enables precise positioning without variable-speed drives or encoders in simple on/off control architectures.
📡
Antenna & Radar Positioning
Satellite dish azimuth and elevation drives, radar antenna rotation drives, and communications tower positioning drives — ultra-low output speed and self-locking characteristics at high ratios suit remote, unmanned positioning applications.
⚙
Precision Industrial Automation
Rotary indexing table drives, slow-speed valve actuator drives, and precision feed screw drives in Australian industrial automation and manufacturing machinery — the double stage NMRV provides high-ratio reduction in an off-the-shelf aluminum housing that fits standard machine frame layouts.
Selection Guide — Choosing the Right Combination
To select the correct double stage NMRV combination, determine three parameters:
- Required output speed (rpm): Divide motor speed by required output speed to get the overall ratio. E.g., 1400 ÷ 0.5 rpm = 2,800:1 overall → two 52:1 stages (use 50:1 + 50:1 = 2,500:1 as the closest standard).
- Required output torque (Nm): The output torque is limited by the second-stage NMRV rating × overall efficiency (0.35–0.55). Match the second stage model accordingly.
- Output shaft diameter: Select the second stage NMRV model whose output shaft matches your driven equipment bore.
Efficiency & Motor Power Sizing Note
Due to two-stage worm drive efficiency of 35–55%, the input motor must be sized at approximately 2× the output power requirement compared to a single-stage drive. For example, to drive a 500 Nm load at 0.5 rpm (approximately 26 W output), a double stage NMRV at 50% efficiency requires approximately 52 W input — a 0.09 kW motor. Always verify motor power against the rated P1 for the first stage model at the selected ratio.
Frequently Asked Questions
❓ What gear ratios are available in the Double Stage NMRV worm gearbox?
Overall ratios from approximately 25:1 to 10,000:1 depending on the combination selected. The most commonly used range is 100:1 to 6,000:1. Ratios are the product of both individual stage ratios — e.g., two 60:1 stages produce 3,600:1 overall.
❓ How does a double stage NMRV worm gearbox work?
Two NMRV worm reducers in series: the output shaft of the first (higher-speed) stage connects directly to the input of the second (lower-speed, higher-torque) stage. Overall ratio = first stage ratio × second stage ratio. Overall efficiency = product of both stage efficiencies (typically 35–55%).
❓ What are the nine standard double stage NMRV combinations?
NMRV025+030, NMRV025+040, NMRV030+040, NMRV030+050, NMRV030+063, NMRV040+075, NMRV040+090, NMRV050+110, and NMRV063+130. The first model in each pair is the input stage; the second is the output stage.
❓ What is the output torque of a double stage NMRV worm gearbox?
Output torque is determined by the second stage NMRV model rating and the overall two-stage efficiency (35–55%). For example, a NMRV050+110 combination at 3,600:1 may deliver approximately 600–900 Nm at overall efficiency. Contact Ever Power for your specific combination torque data.
❓ Can the double stage NMRV be configured for different output shaft orientations?
Yes — since each stage is a right-angle worm reducer, the double stage unit can be assembled with the output shaft at various orientations relative to the motor input, including parallel to input, at 90 deg, or in other spatial arrangements by rotating the second stage mounting position.
Customer Reviews
★★★★★
“We use the NMRV040+090 double stage combination at 3,600:1 on our slow-speed conveyor positioning drives at our automated warehouse in Sydney. Ultra-low output speed of less than 0.4 rpm from a standard 4-pole motor was exactly what we needed for our precision positioning application. Excellent product.”
Scott Whitmore 🇦🇺 — Automation Engineer, Automated Warehouse, Australia
★★★★★
“Specified the NMRV030+063 double stage at 900:1 for our slow solar panel tracking drives in our Austrian installation. The combination provides the exact tracking speed we need from a standard single-phase motor without any additional inverter or gearbox modification.”
Franz Bauer 🇦🇹 — Solar Systems Engineer, Solar Farm, Austria
★★★★½
“Used the NMRV025+040 double stage combination on light-duty antenna positioning drives in our communications equipment. The compact size fit our equipment enclosure without modification and the 1,800:1 ratio gave us precise slow rotation control.”
Xu Guang 🇨🇳 — R&D Engineer, Communications Equipment Co., China
Compatible Accessories & Related Products
🔌
Motor Adaptors (IEC/NEMA)
Input motor adaptors for the first-stage NMRV model — IEC 56B through 90B and NEMA 48C through 140TC depending on combination. Specify first-stage NMRV model and motor frame at order.
🔨
Intermediate Shaft Coupling
Rigid or jaw coupling connecting the output shaft of the first stage to the input of the second stage — pre-selected and matched for your combination by Ever Power engineering team.
🔃
Single Stage NMRV Range
If a single-stage ratio up to 100:1 meets your requirements, the NMRV025–NMRV130 single-stage series offers higher efficiency and simpler installation. Compare efficiency before specifying double stage.
⚙
Custom Ratio Consultation
Not all ratio combinations are listed above. Contact Ever Power engineering for custom first+second stage ratio pairings, non-standard intermediate shaft configurations, and specific efficiency calculations for your application.
Specify Your Double Stage NMRV Combination
Tell us your required output speed (rpm), output torque (Nm), and output shaft diameter — Ever Power engineering will specify the correct combination, ratio pair, and motor power for your Australian or global industrial application.
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