## 1 Introduction
After analysis in ANSYS, they found that the existing mechanism of the cycloid speed reducer was a critical part and they performed an experiment on the real model. The vibration analysis, numerically and experimentally, was conducted by [PERSON] and [PERSON] [24]. The same group of authors also performed one more experiment with a classic type of cycloid speed reducer and a new proposed model [25]. In that experiment, they used an accelerometer on the reducer output to have insight into the output shaft starting and stopping. They also conducted additional research with the same model, where they performed vibration analyses and oscillation modes [25]. Recent research in this field [26] shows the proposed design of a cycloid speed reducer with experimental verification of its functioning. The authors of this research also have a background in this field, both theoretical and experimental papers. A solid foundation in the field of cycloid reducer research was conducted by [PERSON] [27] in his doctoral thesis. Furthermore, [PERSON] et al. [28] set up the single-stage cycloid reducer dynamic model, solved in MATLAB. In later research, a group of authors [29] analyzed the new concept of a two-stage cycloid reducer that uses one cycloid disc instead of two per transmission stage. This research uses an experiment of cycloid disc static loading. [PERSON] et al. [30] conducted FEM and experimental analyses on one cycloid disc from a cycloid speed reducer in static conditions. Interesting research by [PERSON] and a group of authors [31] was conducted similarly to [7], but NASTRAN was used for the solving software. For the new concept of a cycloid speed reducer presented in [PERSON]'s Ph.D. thesis, a complete dynamic model has been given in the paper [32]. In another paper [33], the authors gave complete static analyses for a particular cycloid speed reducer with forces calculated on each reducer element. [PERSON] et al. [34] investigate the influence of friction forces on cycloid drive efficiency. In that paper, they show that friction forces can greatly impact cycloid drive operation due to decreased lubrication in case of oil leakage, lubricant decreased properties during operation, etc. During dynamic load conditions, power transmissions must keep their stability, precision, and endurance. Therefore, examining cycloid speed reductions in dynamic load conditions is very significant. As can be noticed, in the available literature, most papers have analytical and numerical results. Few papers have an experiment. Most of the shown experiments in the available literature are conducted under static load conditions. The problem with static load conditions is that a physical process in the actual working conditions of the cycloidal drive is not simulated properly. Some of the dynamic experiments shown in the literature review only give output values of torque or output of acceleration. These experiments do not give complete insight into what is happening in the cycloid speed reducer during meshing in working conditions. Thus far, the experimental dynamic loading of the cycloid disc in laboratory conditions is not published because the examination methodology is very complex. In this paper, the authors will present a new approach to cycloid disc dynamic testing as well as cycloid disc mesh elements (output pin and meshing tooth). The testing was conducted both experimentally and numerically. The rest of the paper is structured as follows: Section 2 presents the loading cases of the cycloid disc and its theoretical background. Section 3 presents experimental testing. In Section 4, the numerical testing was shown. Section 5 deals with the discussion of the results. At the end of the paper, in Section 6, conclusions are drawn.