What is an NU series worm gearbox?

The NU series is the Anand Gears universal worm gearbox: a single-piece cast iron casing that can be installed either Under Driven or Over Driven, so the same gearbox suits both mounting arrangements. Centre distances run from 60 mm to 205 mm, ratios from 5:1 to 70:1, and power up to 22 kW, with a phosphor bronze worm wheel running against a case-hardened alloy steel worm.

What is the difference between Under Driven and Over Driven?

It describes where the input worm sits relative to the output wheel. On an Under Driven arrangement the worm runs below the wheel; on Over Driven it runs above. Oil level, seal arrangement and the mounting change with it. Because the NU casing is universal, Anand Gears supplies either arrangement from the same body, and a machine can be re-arranged on site without buying a different gearbox.

What NU sizes does Anand Gears make?

Standard NU centre distances are 60, 72, 84, 100, 127, 152, 180 and 205 mm, all with ratios from 5:1 to 70:1 in single reduction. Where more reduction is needed, two stages are combined as a double reduction set and the stage split is worked out per job.

Can an NU gearbox replace an imported unit?

Yes. Send the nameplate and the mounting dimensions and Anand Gears will match the centre distance, ratio, shaft ends and foot pattern so the replacement fits the existing foundation. Because the gears are cut in our own works, a worn worm or wheel can also be replaced on its own instead of buying a complete gearbox.

NU Series Worm Gearboxes — Universal Single-Piece Casing 60–205 CD

Name: NU Series Worm Gearboxes
Brand: Anand Gears

Anand Gears NU series worm gearbox with universal single-piece cast iron casing

Universal Casing

One Casing, Under Driven or Over Driven

The NU series is the workhorse of the Anand Gears worm range. A single-piece universal casing lets the same gearbox be installed Under Driven or Over Driven — the input position changes, the casing does not. That means one spare on your shelf covers both mounting arrangements, and a machine can be re-arranged on site without a new gearbox. Centre distances run 60 mm to 205 mm, ratios 5:1 to 70:1, and power to 22 kW, on a phosphor bronze worm wheel running against a case-hardened alloy steel worm.

Centre distances 60, 72, 84, 100, 127, 152, 180 and 205 mm

Ratios 5:1 to 70:1 in single reduction

Under Driven or Over Driven from the same single-piece casing

Power to 22 kW; higher ratios via double-reduction combinations

Phosphor bronze worm wheel, case-hardened and ground alloy steel worm

Hollow output, hollow input, double input and flanged output built to order

Get a budgetary offer All Worm Gearboxes

Engineering Data

NU Centre Distances and Ratios

The NU sizes Anand Gears builds as standard. Power and torque at your exact duty point are confirmed at the budgetary-offer stage — send the power, input speed, and required output speed.

NU Size	Centre Distance (mm)	Ratio Range	Typical Duty
NU 60	60	5:1 – 70:1	Light conveyors, dosing and packaging drives
NU 72	72	5:1 – 70:1	Conveyors, small mixers, gate and barrier drives
NU 84	84	5:1 – 70:1	Mixers, agitators, material handling
NU 100	100	5:1 – 70:1	Agitators, tube mills, medium conveyors
NU 127	127	5:1 – 70:1	Heavier agitators, winches, process drives
NU 152	152	5:1 – 70:1	Heavy mixers, mill drives, lifting duty
NU 180	180	5:1 – 70:1	Heavy process and plant drives
NU 205	205	5:1 – 70:1	Largest NU frame, heavy continuous duty

Ratios beyond 70:1

Where the output speed calls for more reduction than a single worm stage can give, two stages are combined as a double reduction set, taking the ratio far beyond what one stage can reach. The stage split is worked out per job — tell us the input speed and the output speed you need and we will set it.

Built To Order

NU Arrangements We Build Regularly

The NU casing is the starting point, not the limit. These are arrangements Anand Gears makes as repeat work, not one-off experiments.

Hollow Output Shaft

Machined output bore with keyway so the gearbox slides straight onto the driven shaft — no coupling, no separate bearing block. Torque arm mounting keeps the reaction off the machine shaft.

Double Input Shaft

Input shaft extended both sides for a second drive, a hand wheel, or a brake. Common on machines that need manual jogging during setting.

Double / Three-Way Output

Output taken from both sides of the casing to drive two elements from one gearbox at identical speed — used on twin-shaft mixers and paired conveyor drives.

Vertical Up or Down Output

Output axis turned vertical for stirrers and agitators, with the oil level and seal arrangement changed to suit the mounting.

Flanged Output

Large output flange in place of the plain shaft where the driven element bolts directly to the gearbox — sized to the customer's bolt pattern.

Hollow Input for a Flange Motor

IEC flange motor mounted straight onto the gearbox through a hollow input, removing the coupling and the alignment work that goes with it.

Where It Runs

NU Series Applications

Where Anand Gears NU gearboxes are working today.

Mixers and Agitators

Slow, high-torque stirring in chemical, food, and paint plants — usually vertical output with the ratio picked for the blade tip speed.

Tube and Pipe Mills

Roll drives on tube mills, where the self-locking worm mesh holds the set when the drive stops.

Conveyors and Material Handling

Belt, roller, and screw conveyors — the NU casing lets the drive be flipped between under and over driven when the layout changes.

Winches and Lifting

Slow lifting duty where the worm mesh gives holding torque without a separate brake for the static load.

Plant and Process Drives

General plant machinery where a compact right-angle reduction is needed and the shelf spare must cover several machines.

Machine Builders and OEMs

Repeat build quantities to a fixed drawing, with the mounting and shaft ends held to the OEM's own dimensions.

Replacing an imported unit

Send the nameplate — we will match the mounting

Most NU enquiries start with a failed imported or legacy gearbox. Send a photo of the nameplate and the mounting, or the old unit itself, and Anand Gears will match the centre distance, ratio, shaft ends, and foot pattern so the replacement drops into the existing foundation. We have been building to other makers' mounting dimensions since 1996, and we cut the gears ourselves — so a worn wheel or worm can be replaced without buying a whole gearbox.

Replacement & repair, any make → Gear cutting job work → Custom & special builds →

Budgetary offer — NU Series Worm Gearboxes

Tell us the duty and we’ll send you a number

Power, input speed, and either the ratio or the output speed you need are usually enough to start. Our engineers reply on the same working day.

Have a nameplate photo, a drawing, or the old unit in front of you? Send it on WhatsApp — that is the fastest route to a number.

Prefer to talk? +91 98203 83719 or +91 98205 18093.

NU Series Worm Gearboxes