M-TEK designs and produces Single Axis Positioners (SAP), based on three different technologies, namely:
- Direct Drive
- Harmonic Drive®
The technology selected will depend on the application, size of the load, acceleration and maximum velocity, angular tell-back accuracy, environmental conditions, cost and other factors. For all the SAP’s, slip ring assemblies, brakes, parking latches, etc can be implemented.
Angular feedback is mainly accomplished with integrated absolute resolvers or optical encoders with tell-back accuracy of up to 0.1 mRad, if required. For controlling the SAP’s, a range of Servo Amplifier Units (SAU) are used, with peak voltages ranging from 28 VDC to 200 VDC and currents up to 80 A. Control of the SAU’s are via various serial busses including RS232, RS422 and others.
Direct Drive SAP
For Direct Drive SAP’s, brushless DC torque motors are structurally coupled to the load as effectively possible, in order to produce a system with maximum stiffness (very low to zero backlash) and high torsional and acceleration response capability. Typical applications include direction finding antennas, periscopes, etc. Direct Drive SAP’s with peak torques ranging from 5 Nm to 1200 Nm have been produced.
Harmonic Drive® SAP
Harmonic Drive® SAP’s produces high peak torques with low maximum current, and very low backlash. A Harmonic Drive® speed reducer, with ratios of 50:1, 80:1 and higher, is coupled to a brushless DC torque motors, in order to produce high torque. Typical applications include accurate positioning of large dish antennas which are susceptible to high wind loads. Harmonic Drive® SAP’s with peak torques ranging from 30 Nm to 600 Nm have been produced.
Geared SAP’s produces high peak torques with low maximum current, which is achieved with the implementation of a slew gear/planetary gear box or worm gear combination, with typical gear ratios of 60:1 or higher. Backlash will be evident in these positioners.
Typical applications include positioning of large dish antennas which are susceptible to high wind loads, with a relatively low angular accuracy requirement. Geared SAP’s with peak torque of 300 Nm have been produced.