When electric motors have special requirements due to performance criteria, size or environment that have not been designed for before, HMK have the skills and expertise to supply custom motor solutions, working with customers through all phases from the design through to assembly and testing.

The Application

When faced with the challenge of controlling a narrow textile web to a tension of sub 5N at 30m/min, the engineering team at HMK had to draw on its combined 300 years of application experience to create the right solution.

We needed to find a solution with almost zero cogging torque, capable of 3000rpm to direct drive the unwind package, requiring the spindle of the package to connect directly to the motor shaft and which would take its unwind speed feedback from a small stroke dancer only.

The negation of cogging torque ruled out servo motors with their magnets, the speed range dictated direct drive, the tight speed control ruled out a standard VSDs, the low tension needed no oil seals and special bearings and the direct package connection was going to need a modified motor shaft.

The Solution

We took a quality AC induction motor, pressed out the old shaft from the rotor and machined a bespoke shaft for fast package connection. This was combined with a new output flange, low friction ceramic bearings and special lubricant - re-assembled and tested at our Radnor facility. 

HMK combined this with the high dynamic response of the Sinamics S-series drive from Siemens to create a winning combination.