Vortex VMRV-Series IEC Metric Worm Gear Reducers

The Vortex VMRV-Series is an IEC metric standard worm gear speed reducer with cast iron housing, NEMA C-face input flange, and hollow output bore for direct shaft mounting. Available in seven center-distance sizes (VMRV-30 through VMRV-110 millimeters) and twelve nominal ratios from 5:1 through 100:1, the VMRV-Series is a direct interchange for Motovario NMRV and other IEC metric worm gear brands. Texas Belting and Supply stocks the complete Vortex VMRV line in Houston for same-day shipping on metric worm gear replacement applications.

About the Vortex VMRV-Series

The VMRV-Series follows the IEC metric worm gear standard that originated with European industrial gear manufacturers. The unit size designates the center distance in millimeters: a VMRV-50 has a 50 mm center distance, a VMRV-110 has a 110 mm center distance. This is the same sizing scheme used by Motovario NMRV, Bonfiglioli VF, SEW-Eurodrive S-Series, and other IEC metric worm gear brands, which makes the VMRV the right Vortex part number to specify when replacing a European-standard worm gear reducer on existing equipment.

Each VMRV unit ships with a NEMA C-face input flange (56C, 140TC, or 180TC depending on size), a hollow output bore that mounts directly over the driven shaft, and a corrosion-resistant housing sealed for industrial service. Compact sizes (VMRV-30 through VMRV-75) use a die-cast aluminum housing for low weight and corrosion resistance; larger sizes (VMRV-90 and VMRV-110) may use cast iron for higher torque capacity. Output accessories (cover, output flange, single-ended solid shaft, double-ended solid shaft, torque arm) are sold separately and selected based on the mounting configuration of the driven equipment.

Available Sizes and Ratios

VMRV center distances follow the IEC metric standard. Use this table to identify the right VMRV size for your motor HP, motor frame, and required gear ratio:

How to Read a Vortex VMRV Part Number

VMRV part numbers follow a structured format. Take VMRV-50-15-56C as the example:

Applications

VMRV-Series worm gear reducers are used wherever a compact IEC metric standard worm gear reducer is needed for fixed-speed power transmission. Typical installations include:

• Replacement of Motovario NMRV reducers on existing OEM machinery
• Replacement of Bonfiglioli VF, SEW S-Series, and other European metric worm gear reducers
• Conveyor and roller drive applications using metric sizing standards
• Packaging machinery and food processing equipment built to European standards
• Mixers, agitators, and metering drives in chemical and pharmaceutical processes
• OEM machinery designed around IEC metric drive components
• Industrial fan and blower drives in process ventilation systems

Competitor Cross-References

The Vortex VMRV-Series interchanges directly with the major IEC metric worm gear reducer brands. Because all IEC metric worm gear reducers use the same center-distance-in-millimeters sizing convention, cross-reference is straightforward: match the existing reducer size, ratio, and motor frame to the corresponding Vortex VMRV part. Verify input flange designation (NEMA C-face vs IEC B5) and output configuration (hollow bore vs output shaft vs output flange) when substituting.

Motovario NMRV provides the most direct cross-reference: a Motovario NMRV-50-15 maps to a Vortex VMRV-50-15 at the same motor frame. For exact cross-reference assistance with non-Motovario brands, call (888) 203-2358.

Selection Guide

To select a Vortex VMRV reducer for your application, work through five questions in order:

1. What is the IEC size you need? If you are replacing a Motovario NMRV or other IEC metric worm gear, the existing nameplate already tells you the center distance in mm (30, 40, 50, 63, 75, 90, or 110). Match it directly to the corresponding VMRV-[size].
2. What output speed do you need? Output RPM equals motor RPM divided by ratio. A 1750 RPM motor through a 30:1 VMRV gives 58.3 RPM at the output.
3. What motor frame are you driving with? Confirm the VMRV size you are considering supports your motor frame. Smaller sizes (30, 40, 50, 63) typically accept 56C and 140TC; larger sizes (75, 90, 110) add 180TC.
4. What output configuration do you need? All VMRV units ship with a hollow output bore. If your driven equipment requires a solid output shaft, an output flange, or a double-ended shaft, order the corresponding accessory (OSS, OSF, or OSD) sized to the VMRV.
5. Is a torque arm needed? When the VMRV is hung on the driven shaft via its hollow output, a torque arm (TA) is required to react the housing torque to a stationary frame. The TA is sized to the VMRV.

If you would prefer that we size the complete drive package for your application, call (888) 203-2358 or open a quote with the existing nameplate (Motovario, Bonfiglioli, etc.) plus your motor HP, frame, and driven shaft size. We will spec the right Vortex VMRV and accessories and confirm stock from Houston.

Frequently Asked Questions

What is the Vortex VMRV-Series worm gear reducer?

The Vortex VMRV-Series is a compact IEC-standard metric worm gear speed reducer with cast iron housing, NEMA C-face input flange, and hollow output bore for direct shaft mounting. Available in seven center-distance sizes (30 mm, 40 mm, 50 mm, 63 mm, 75 mm, 90 mm, and 110 mm) and twelve nominal ratios from 5:1 through 100:1. The VMRV-Series is a direct equivalent for Motovario NMRV reducers and interchanges dimensionally with most IEC metric worm gear brands at matching size and ratio.

How do I read a Vortex VMRV part number?

VMRV part numbers follow the format VMRV-[size]-[ratio]-[motor frame]. Take VMRV-50-15-56C as the example. VMRV identifies the series. 50 is the unit size and also the center distance in millimeters (50 mm between the worm centerline and output shaft centerline). 15 is the nominal gear ratio (15:1). 56C is the NEMA C-face motor frame the input flange accepts. Sizes are 30, 40, 50, 63, 75, 90, and 110 millimeters; nominal ratios are 5, 7.5, 10, 15, 20, 25, 30, 40, 50, 60, 80, and 100.

Does the Vortex VMRV cross-reference to Motovario NMRV?

Yes, directly. The VMRV-Series uses the same IEC sizing scheme as Motovario NMRV, so a Motovario NMRV-50-15-56B5 cross-references to a Vortex VMRV-50-15-56C at matching size, ratio, and motor frame. The dimensional interchange extends to Bonfiglioli VF-Series, SEW-Eurodrive S-Series, STM RV/RT-Series, Brevini RV-Series, and other IEC-standard metric worm gear brands. Always verify motor frame designation (56B5/56C, 71B5/140TC, etc.) and confirm output configuration (hollow shaft, output flange, or solid output shaft accessory) when substituting.

What sizes and ratios are available?

The VMRV-Series active inventory at Texas Belting and Supply covers seven sizes (VMRV-30 through VMRV-110) and twelve nominal ratios (5:1, 7.5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 40:1, 50:1, 60:1, 80:1, and 100:1). Not every size offers every ratio, and motor frame options scale with size. See the size availability table above for the per-size ratio and frame matrix. Special configurations and ratios not stocked may be available as special-order with one to three week lead times.

What accessories does the VMRV-Series use?

Each VMRV size has its own set of compatible accessories: an output cover (CVR), output shaft double-ended (OSD), output flange (OSF), output shaft single-ended (OSS), and torque arm (TA). The cover is used when the unit is mounted with the hollow bore facing into a frame. The output flange converts the hollow output to a flange-mounted output. The output shaft accessories convert the hollow output to either a single-ended or double-ended solid output shaft. The torque arm reacts torque to a stationary frame when the unit is hung on the driven shaft via the hollow bore. All accessories are sold separately and must match the VMRV size.

What is the difference between VMRV and the Vortex X-Series worm gear reducers?

Both VMRV and X-Series are worm gear speed reducers, but they target different markets. X-Series (and the related XS, XH) uses American inch-based sizing (X133, X175, X206, etc.) with center distances in inches and standard NEMA C-face motor frames. VMRV uses European IEC metric sizing (VMRV-50, VMRV-90, etc.) with center distances in millimeters, and is designed as a direct interchange for Motovario NMRV and similar IEC metric worm gear lines. Choose X-Series for replacement of American worm gear reducers (Dodge Tigear, Hub City, Boston Gear, etc.) and VMRV for replacement of European IEC metric worm gear reducers (Motovario, Bonfiglioli, SEW, etc.).

Does the VMRV-Series ship from Houston?

Yes. All Vortex VMRV-Series reducers in our active inventory ship from Texas Belting and Supply's Houston, TX warehouse the same business day for orders placed before 3 PM Central time. Standard sizes VMRV-30 through VMRV-110 in common ratio and motor frame combinations are generally stocked. Non-stocked configurations may have a one to three business day lead time. Call (888) 203-2358 to confirm current inventory and request a quote.