Reducers are commonly used in many types of machines to reduce the speed and increase the torque of motors. For general industrial applications, the reduction ratio of a reducer is usually limited in consideration to its size. To provide high reduction ratios, harmonic drives (speed reducers) can be made very compact and lightweight and thus have been popular with robot manufactures and in other applications where weight is critical. In this study, an innovative design for reducers composed of planar cams and roller followers with high reduction ratios is proposed. It uses the relative motion between rollers and their cams to generate a high reduction ratio. In this thesis, the synthesis procedure of the reducer and the analysis results of the kinematic and dynamic characteristics based on the design parameters are also described. Furthermore, the experiments for testing and verifying the characteristics of the reducer are presented. Finally, a set of design parameters which meets the demand of an application is found by optimization methods.

No description available.

No description available.

The performance and lifetime of lithium-ion batteries are strongly influenced by their composition. One category of critical components are electrolyte additives, which are included primarily to stabilize electrode/electrolyte interfaces in the battery cells by forming passivation layers. The presented study aimed to identify and study such an additive that could form a hydrogen-evolution-suppressing solid electrolyte interphase (SEI) in lithium-ion batteries based on aqueous electrolytes. A promising molecular additive, ethyl 2,2-difluoroacetate (EDFA), was found to hold the qualities required for an SEI former and was herein further analyzed electrochemically. Analysis of the battery cells were performed with linear sweep voltammetry and cyclic voltammetry with varying scan rate and EDFA concentrations. Results show that both 1 and 10 w-% EDFA in the electrolyte produced hydrogen-evolution-suppressing SEI:s, although the higher concentration provided no apparent benefit. Lithium-ion full-cells based on LiMn2O4 vs. Li4Ti5O12 active materials displayed poor, though partly reversible, dis-/charge cycling despite the operation of the electrode far outside the electrochemical stability window of the electrolyte. Inclusion of reference electrodes in the lithium-ion cells proved to be immensely challenging with unpredictable drifts in their electrode potentials during operation. To summarize, HER-suppressing electrolyte additives are demonstrated to be a promising approach to stabilize high-voltage operation of aqueous lithium-ion cells although further studies are necessary before any practical application thereof can be realized. Electrochemical evaluation of the reaction mechanism and efficiency of the electrolyte additives relies however heavily on the use of reference electrodes and further development thereof is necessary.