In a recent email exchange with London-based John Hammerbeck of Ascending Power, we learned more about a novel new linear-motion extension technology from the company. The actuator steps up a short input stroke to a long output stroke using either kinematic linkages or permanent magnets.
Below is a SolidWorks animation of the linkage variation; depending on application requirements, the actuator can extend forward without forward supports or within a guide frame.
Stroke-extending linear technology basics
How does it work? The stroke extender is a step-up linear gear — essentially a short input stroke on a lever — with input from a wide-diameter pneumatic piston, bellows, solenoid to produce a long output stroke. Input can also be from a stepper motor’s partial rotation. Engineers can increase the input to output (to the limits of friction) in two ways:
- By adding more expanding units
- By locating the input closer to the axis.
The stroke-extending linear technology also comes in a variation based on permanent magnets (instead of linkages) for designs needing lower friction. Rollers on support slides further reduce friction.
Stroke-extending linear technology operating characteristics
The component’s ability to lengthen stroke distance and speed means it imparts unique characteristics to linear-motion applications. Because the linkages travel in an arc, forward speed slows as the device comes to full extension. Plus the linkages come into toggle at full extension … for high terminal force. The latter could be useful for mechanical transmission to clamps, grippers, or other end effectors.
Potential applications stroke-extending linear technology
Ascending Power’s device could one day improve ballscrew mechanisms (with increased speed). The magnetic version (using magnetic slides and pneumatic input) could also work in applications needing to stay free of contamination — in cleanrooms and for food processing, for example. The linkages version of the stroke-extending technology at least can be manufactured from commercial off-the-shelf component, so is a cost-effective solution.