Closed-loop two-fold tape spring transmissions

Closed-loop two-fold tape spring transmissions

Houwers, H.W.R.

Radaelli, G. (mentor)
Herder, J.L. (mentor)

Mechanical, Maritime and Materials Engineering

PME

MSD

2016-01-29

Background: Compliant mechanisms have the advantage of low weight, no lubrication, no wear and no friction. These are good properties for a mechanical transmission. But large range of motion (ROM) in compliant mechanisms is a challenge. If the ends of a long shell with only a transverse curvature are connected, a two-fold closed-loop tape spring (tape loop) is created which is a rectilinear joint with an large ROM. The objective of this thesis is to present and analyze a new transmission concept formed by connected tape loops in a configuration that transmits a tension force around a body. Method: A model of the force deflection behavior along the two main axes of a tape loop was made and verified with experiments. This model was implemented in a model of a transmission formed by connected tape loops with a tendon under a relative angle. This model was also experimentally validated. Results: The models and experiments show the same kind of for deflection behaviour with increasing stiffness for larger deflections, but can differ up to 50%. For a 103mm tape loop a ROM of 39mm was obtained. The measured efficiency of the transmission is between 91.6% and 96.8%, and is depending on the load. Conclusions: The behaviour of the transmission can be described in terms of the design parameters. It was found that there is a trade-off between ROM and stiffness and that they scale with the size of the transmission.

Compliant Mechanisms
tape spring

http://resolver.tudelft.nl/uuid:5b242e4e-12a3-489e-9637-41d4fb9ab0f0

Student theses

master thesis

(c) 2016 Houwers, H.W.R.