Showing papers by "Nima Tolou published in 2017"

Reciprocating Geared Mechanism with Compliant Suspension

Abstract: We present a novel cycloidal geared mechanism with a continuous rotational input featuring a reciprocating translational output. A statically balanced compliant mechanism suspends an annulus driven by a cycloidal rotor. The freedom and constraint topology design method is used to synthesize the compliant suspension. A fixed transmission ratio of 15 results from the ratio between the cycloidal rotor and the annulus. The static balancing conditions of the suspension are developed analytically, and validated using finite-element modeling and experimental results. Moreover, the estimation of the frictional loss as a function of the stiffness of the compliant members is derived using a force analysis of the system and verified using experimental data. A case study on a mechanical watch yields dimensions for the prototype, which is fabricated in silicon using deep reactive ion etching. Experiments show that energy loss as a function of the stiffness of compliant members is marginal and independent of the position of the compliant suspension. [2016-0260]

Device for a timepiece, timepiece movement and timepiece comprising a device of said type

Abstract: Device for a timepiece, comprising a one-piece mechanism (13) that includes a support (15) and an inertial adjusting element (29, 30) which is connected to the support by a flexible suspension (31; 36, 55). The flexible suspension includes a flexible adjustment link (36, 55), one end of which is adjustable relative to the support in such a way that the overall stiffness of the flexible suspension, and thus the oscillation frequency of the inertial adjusting element, changes.

Monolithic and Statically Balanced Rotational Power Transmission Coupling for Parallel Axes

Abstract: A new fully compliant rotational power transmission mechanism is presented. The design is based on the Pseudo-Rigid-Body Model (PRBM) of the Oldham constant velocity coupling. It can be fabricated as a single piece device with planar materials which make it suitable for micro scale applications. The internal stiffness of the proposed structure is eliminated by static balancing technique. Therefore, the compliance and zero stiffness behavior compensate for the structural error and poor efficiency inherent in rigid-body Oldham coupling, resulting in high mechanical efficiency power transmission system. The device is designed and its motion, torsional stiffness, and torque-angular displacement relations are predicted by the PRBM and finite element modeling. A large/macro scale prototype was manufactured and measured to evaluate the concept. This high efficient power transmission system can be applied in different applications in precision engineering and the relevant field such as micro power transmission system.

Position-adjustable micromechanism, time-keeping movement and timepiece comprising such a mechanism

Abstract: The invention relates to a micromechanism comprising a first part (15), a second part (53) having a position that can be adjusted in relation to the first part, and a locking device (56) for locking the second part in position in relation to the first part. The locking device comprises an elastic bearing body (63) connected to the first part, a first adjustment finger (58a) connected to the first part, and a second adjustment finger (57a) connected to the second part and extending in the opposite direction to that of the first adjustment part, and the elastic bearing body (63) is designed to exert pressure on the second adjustment finger by frictionally locking it against the first adjustment finger.