What is an NMRV worm gear reducer?
The NMRV Motovario worm gear reducer (VSF series) is an Italian reducer with aluminium or cast iron housing, designed for industrial drive applications requiring low output speed and high torque. The NMRV worm gearbox range covers ten sizes — from NMRV025 to NMRV150 — plus the NMRVpower series (063–110) for higher power and torque ratings. Nibora Ltd offers NMRV gearboxes on request and individual configuration — contact us for a quote and technical consultation.
Unlike the NBR series (Nibora's own brand, available from stock), NMRV Motovario gearboxes are ordered and configured individually — an advantage when ATEX certification, non-standard mounting positions or precise technical parameters are required. Warranty: 2 years from delivery.
Series and Technical Data
| Size | Weight (kg) | Input Power P1 (kW) | Max M2 (Nm) | Output Shaft | Ratio i | Housing |
|---|---|---|---|---|---|---|
| NMRV 025 | ~0.7 | up to 0.12 | ~17 | Ø9 H7 | 5–100 | aluminium |
| NMRV 030 | ~1.2 | up to 0.25 | ~30 | Ø14 H8 | 5–100 | aluminium |
| NMRV 040 | ~2.0 | up to 0.55 | ~85 | Ø18 H8 | 5–100 | aluminium |
| NMRV 050 | ~3.0 | up to 0.75 | ~140 | Ø25 H8 | 5–100 | aluminium |
| NMRV 063 | ~5.5 | up to 1.10 | ~200 | Ø25 H8 | 5–100 | aluminium |
| NMRV 075 | ~8.5 | up to 1.50 | ~300 | Ø28 H8 | 5–100 | aluminium |
| NMRV 090 | ~12.0 | up to 2.20 | ~450 | Ø35 H8 | 5–100 | aluminium |
| NMRV 110 | ~28.0 | up to 4.00 | ~700 | Ø42 H8 | 5–100 | aluminium |
| NMRV 130 | ~42.0 | up to 9.20 | ~1,050 | Ø45 H8 | 5–100 | cast iron |
| NMRV 150 | ~75.0 | up to 18.5 | ~1,550 | Ø50 H8 | 5–100 | cast iron |
Mounting Positions
NMRV gearboxes are available in six standard mounting positions. For sizes 025–075, position B3 is valid for B6/B7/B8/V6 without changing the oil quantity. For sizes 090–110, positions V5 and V6 must be specified at order. For sizes 130–150, all positions must be specified explicitly.
| Code | Description (EN) |
|---|---|
| B3 | Horizontal mounting, floor support |
| B6 | Wall mount, output downward |
| B7 | Wall mount, output upward |
| B8 | Ceiling mount |
| V5 | Vertical mount, input upward |
| V6 | Vertical mount, input downward |
Versions and Accessories
- NMRV – standard, with PAM flange for direct IEC motor mounting
- NRV – gearbox only (no motor flange), with input shaft
- NMRVpower (063–110) – enhanced series with higher torque and power
- NMRL – with torque arm
- HA31+NMRV040/050 – pre-reducer for extended ratio range
- HW 030/040+NMRVpower – compact two-stage configuration
- ATEX version: 2GD/3GD – for explosive atmospheres (Ex zones)
Key Technical Features
- Worm wheel: bronze CuSn12Ni2 (UNI7013-10) – high wear resistance
- Worm profile: ZI ground (UNI4760) – high meshing precision
- Lubrication: ENI TELIUM VSF synthetic oil – universal mounting, lifetime fill
- Housing: RAL 5010 blue epoxy-polyester powder coating
- IP protection: IP55 standard
- Standards: ISO 14521, DIN 3996, BS 721, AGMA 6034
- Corrosion resistance: salt fog ASTM B117 100–500 hours
- ATEX certification: 2GD/3GD per Directive 2014/34/EU
How to Order
NMRV gearboxes are available on request. To prepare a quote, please specify: size (e.g. NMRV063), gear ratio (e.g. i=40), mounting position (e.g. B3), version (NMRV/NRV/ATEX) and motor frame size. We respond within 2–4 working hours.
Tel. +359 64 681 058 | nibora@nibora.com | nibora.com
NMRV Catalogue
Download PDF ↓Frequently Asked Questions (FAQ)
What is the difference between NMRV and NBR gearboxes?
NBR is Nibora's own brand — in stock in Pleven with 24–48h delivery and competitive pricing. NMRV is Motovario (Italy) — ordered and configured individually. NMRV advantages: ATEX certification, wider size range (025–150), power up to 18.5 kW, more mounting positions.
Are NMRV gearboxes self-locking?
Yes – at gear ratios above 20:1 the worm gear is self-locking. Motovario publishes exact irreversibility values in the catalogue for each size and ratio.
Can NMRV gearboxes be used in ATEX environments?
Yes – the ATEX version is certified per Directive 2014/34/EU for groups 2GD and 3GD. Please specify the ATEX requirement and zone when ordering.
What is the delivery time for an NMRV gearbox?
Depends on configuration. Standard sizes and ratios – typically 5–15 working days. Special configurations (ATEX, non-standard shaft, pre-reducer) – confirmed individually. Contact us for exact timing.
Does the synthetic oil require changing?
Under standard conditions (-25°C to +40°C), the oil is a lifetime fill. For sizes 130 and 150, check the oil level when changing the mounting position.
Are NMRV gearboxes compatible with IEC motors?
Yes – NMRV version has PAM flange B5 or B14 for direct IEC motor mounting. NRV version is gearbox only with input shaft, without motor flange.