Gearboxes
PC pre-stage units
A PC unit is a pre-stage reducer that works as part of a drive with a worm gearbox. It takes a first, threefold cut in motor speed before the drive reaches the worm gear, which makes it easier to arrive at the output speed and torque the machine needs. Combined with a worm gearbox, the pair reaches ratios up to i=300.
The build is modular, so a PC unit can be fitted with any type of worm gearbox. That matters when a standard gearbox is right on torque but not on speed: adding the pre-stage multiplies the ratio instead of forcing a change of gearbox, and the drive keeps the components it already has.
PC units suit drives where the running has to be predictable, the parameters have to repeat and the arrangement has to be matched to the machine. We size them on the mounting, the layout of the drive and the conditions the machine works in. Send us those details with the worm gearbox you are using, and we will quote within one working day.
Main features
Pre-stage reducer used with a worm gearbox
Threefold reduction of motor speed before the worm gear
Combined ratios up to i=300 with a worm gearbox
Modular build fits any type of worm gearbox
Keeps the drive on standard gearbox components
Questions we get asked
What does a PC pre-stage unit do?
It reduces motor speed by a factor of three before the drive reaches the worm gearbox. The gearbox then takes its own reduction from a lower input speed, so the combination reaches ratios up to i=300. It is a way of getting a low output speed out of standard components rather than a special gearbox.
Will a PC unit fit my worm gearbox?
The modular design is meant to work with any type of worm gearbox, which is why it is used as an addition rather than a redesign. We still check the mounting arrangement and the layout of the drive before quoting, because the unit has to line up with the gearbox and sit sensibly in the machine. Send the gearbox details and we will confirm.
What ratio can I reach with a PC unit and a worm gearbox?
Up to i=300 for the pair. The PC unit contributes the threefold reduction and the worm gearbox provides the rest. Tell us the output speed and torque you need at the machine, along with the motor speed, and we will work out whether the pre-stage is the right way to get there.
When is a PC unit a better answer than a different gearbox?
When the drive needs more reduction than the gearbox gives, but the rest of the specification already suits. Adding the pre-stage keeps the existing worm gearbox and takes the combined ratio to i=300, with predictable running and settings that repeat. Where torque is the limit rather than speed, we look at the gearbox size instead.
Other gearboxes
Request a quotation
Quote for pc pre-stage units
Reply within one working day with a price, a lead time and the datasheet.
What lets us quote first time
- Worm gearbox series and size
- Total ratio needed
- Motor frame