The multi-speed internal gear hub of a bicycle is a well-closed gear shifting system that works perfectly under any challenging riding environment, and is developed specifically to improve fragile chain-drive derailleur using planetary gear trains. In recent years, bicycle internal hub gears have been developed toward multi-speed transmission, and in the development process of internal gear hubs, the structure of speed changing mechanism has changed from a single planetary gear train to multiple planetary gear trains, and is becoming more complex. The primary purpose of this Study aims to establish a systemized and efficient design process, and develop an effective theory and method for designing multiple-speed internal gear hubs with the design concept and common features of multiple-speed internal gear hub products developed in recent years, to favor the innovation and development of internal gear hubs. First, existing multiple speed internal hub products are analyzed and summarized for their basic features, limitations, and demands as the reference for the design of multiple speed internal gear hubs, and a catalog of usable planetary structures is systematically established with the coupling and connection of basic high and low ratio speed changing modules. Secondly, usable planetary structures that offer best performance of geometric progression speed ratio distribution of gear hub are matched with gear positions, and a table of gear sequence is confirmed; third, based on the maximum external diameter required by design, tooth numbers for every gear in a hub are defined according to the relationship between tooth number and speed ratio, as well as the gear sequences; and finally, the systematic design process above is applied to the development of an easy-to-use computer aided design software with the lowest possible number of variables using Visual Basic 6.0 for designers, in order to favor the innovation and development of internal gear hubs.

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The subject of this study is a proposal to streamline the production process of gear with internal gear. At the beginning of the thesis are described some types of gearing. The second chapter is focused on the analysis of manufactured part and workplaces for production. The third chapter contains description of technological methods of gearing production by conventional and unconventional methods. The main point of this work is a proposal of innovation of the production process of gearing production. In conclusion, technical-economic evaluation including a comparison of existing and newly designed solutions.

In recent years, additive manufacturing (AM) has become one of the most revolutionary and promising technologies in manufacturing. The process of making a product layer by layer is also often referred to as 3D printing. Once employed purely for prototyping, AM is now increasingly used for small series production, for example in aerospace applications. The paper starts with a motivation for AM in hydraulic applications and the development of an AM internal gear pump. For a better understanding of the manufacturing process, a brief introduction to AM highlighting the advantages and challenges is given. The AM internal gear pump is part of an electrohydraulic power pack, which is used to power an electrohydraulic actuator (EHA). The power pack contains all necessary peripherals to realise the hydraulic system of the EHA. The AM process allows for new design possibilities, but the process differs strongly compared to subtractive manufacturing processes and therefore is outlined here. The paper concludes by presenting measurement results of the AM internal gear pump.

Oil lubrication film plays an important role in analysis of dynamic behavior of the internal gear motors and pumps. During operation, the oil film is considered as the spring and damping system. Therefore, calculation of the dynamic stiffness and damping coefficients is necessary to build the mathematical model for studying of dynamic problem. In order to calculate these coefficients, the dynamic pressure and perturbing pressure distribution must be determined firstly. In this paper, the infinitesimal perturbation method (IFP) is used to calculate the dynamic pressure distribution. Based on that the dynamic stiffness and damping coefficients can be computed. The calculation results point out that the dynamic stiffness and damping coefficients are much dependent on the eccentricity ratio.