New zero-backlash maxon gearbox enhances precision

maxon has released a zero-backlash gearbox, enabling a DC or brushless DC (BLDC) drive system to achieve the highest level of precision. The new GSW A gearbox, based on strain wave technology, also offers a high reduction ratio in a compact footprint, capable of delivering up to 71 Nm torque. These features give the GSW A strain wave gearbox an advantage for applications that demand optimum control in a small, lightweight package. 

The GSW A gearbox achieves zero backlash thanks to its strain wave design. Based on elastic deformation, the strain wave operating principle ensures continuous engagement of the gear teeth, removing the lowest tolerances of mechanical play to increase precision.

The operation of the strain wave design includes a flexible cup with external gear teeth, known as the flex spline. This cup is deformed by the wave generator, a rotating disc that compresses the flex spline into an elliptical wave that continuously engages with the gear teeth of a third, outer ring. This transmission process ensures zero backlash combined with smooth torque transmission, optimising high-precision motion.

The GSW A strain wave gearbox achieves high torque generation as the design can engage a greater proportion of gear teeth, improving load distribution and optimising torque density. The gearbox delivers up to 27 Nm continuous torque, as well as 37 Nm intermittent torque, and 71 Nm overload torque. High reduction ratios in a single stage are also available, including up to 100:1, as well as 80:1, and 50: 1.

While high tortional rigidity enables the GSW A gearbox to transmit motion without delay, low mass enhances high dynamics, with designs available in 300g and 460g options. The new gearbox can also operate at input speeds up to 8,500 rpm intermittent duty.

Backdrive is an important feature of the GSW A gearbox, enabling the output shaft to drive the input shaft in reverse. Allowing manual intervention of a robot arm. This is an important safety feature, which can also be used for robot teaching.

The form factor of the strain wave design lends itself to integration into space-restricted applications. With a flat profile, the 55mm-diameter version is just 30.3mm in length, while the 62mm-diameter design is 32.4mm long. The gearbox also features a hollow bore, enabling through routing of cables.

These features make the maxon GSW A gearbox advantageous for robot designers, particularly in applications that demand the highest precision, such as distal arm joint control for surgical robots. Low mass also makes the gearbox design a preferred choice for aerospace applications where every gram counts.

maxon also integrates its GSW A gearbox within its HPJ High Precision Joints modules for robot designers. Integrating a brushless DC motor, the strain wave gear, plus a dual encoder layout, the complete HPJ unit matches control precision with ease of design integration.

“For application designers who require precision motion control for DC and brushless DC motors, the strain wave gearbox is the pinnacle,” says maxon UK & Ireland Managing Director, William Mason.  “With zero backlash, the new GSW A strain wave gearbox will enhance control, alongside high torque transmission in a compact design.”

To find out more about the new GSW A strain wave gearbox, visit here.