Gear reducers

A gear reducer is the gearbox on its own, without a motor. You buy one when you already have a motor with a suitable flange, when you are replacing a worn gearbox in a machine, or when you want to choose the drive for the reducer yourself. This category includes new worm gear reducers in sizes from 30 to 150, as well as individual used and unused units, checked before dispatch.

Worm gear reducers 30–150

Sizes 30–90 have an aluminium housing, while 110, 130 and 150 have a cast-iron housing. Every reducer has an IEC-standard motor flange, so it fits typical motors with a B14 or B5 flange. On the reducer's product page you choose the size and ratio, and the shop shows the output speed. It is easy to calculate: divide the motor speed by the ratio, so a 1400 rpm motor with a 1:30 reducer gives approx. 47 rpm.

Gear reducer and motor in one order

For many reducers you can immediately add a motor from our stock, new or used. We then assemble a complete drive and ship it as one unit, with assembly included in the price. If you are looking for a factory-built unit, see our gearmotors.

Used gear reducers

In addition to new units, we have individual worm and helical reducers from dismantled machinery and from warehouse stock. The condition of each unit is stated on the product page. This is a good solution when you need a replacement for an older machine.

How to choose a gear reducer

You need three things: the output speed, the power or torque, and the motor frame size and flange. If you have questions about a specific reducer, e-mail or call us. For sizes 30–130 we also have accessories: torque arms, output shafts and side flanges.

Worm gearbox sizes and matching motors

The gearbox size is the centre distance between the worm and the worm wheel in millimetres. It determines the output shaft bore and which motors can be fitted. The motor interface gives the motor frame size and flange type: 71B14 means a frame size 71 motor with a small B14 face flange, and 80B5 a frame size 80 motor with a large B5 flange. Data according to STN dimension sheets.

Size	Output bore	Motor interfaces	Weight
30	Ø 14 mm	56B14, 63B14, 56B5, 63B5	1.2 kg
40	Ø 18 mm	63B14, 71B14, 56B5, 63B5, 71B5	2.3 kg
50	Ø 25 mm	71B14, 80B14, 63B5, 71B5, 80B5	3.5 kg
63	Ø 25 mm	71B14, 80B14, 90B14, 71B5, 80B5, 90B5	6.2 kg
75	Ø 28 mm	80B14, 90B14, 100/112B14, 71B5, 80B5, 90B5, 100/112B5	9 kg
90	Ø 35 mm	80B14, 90B14, 100/112B14, 80B5, 90B5, 100/112B5	13 kg
110	Ø 42 mm	80B5, 90B5, 100B5, 112B5, 132B5	35 kg
130	Ø 45 mm	90B5, 100B5, 112B5, 132B5	48 kg
150	Ø 50 mm	100B5, 132B5, 160B5	84 kg

We show step by step how to calculate the ratio, torque and service factor in our guide how to choose a worm gearbox. For a comparison with helical and bevel-helical gearboxes, see our article on types of gearmotors.