Efficiency Analysis of New Two-Stage Cycloid Drive Concept (original) (raw)

A COMPARATIVE CALCULATION OF CYCLOID DRIVE EFFICIENCY

Machine Design, 2020

Determining cycloid drive efficiency is a very complex task that in the most cases requires theoretical analysis, numerical calculation, computational simulations and experimental research. The paper aims to compare the results obtained based on two so far the most recognized and acceptable theoretical models (Malhotra model and Kudryavtsev model). On the one hand, the presented models are very similar (they both take into account the power losses due to friction on the central gear rollers, output rollers and in the cycloid gear bearings). They differ in the methodology of power losses calculation and in the number of contacts between certain cycloid drive elements that are taken into account. The computational simulation was performed in the MATLAB software package on specific examples of classical singlestage cycloid drives.

INFLUENCE OF THE FRICTION ON THE CYCLOIDAL SPEED REDUCER EFFICIENCY

Journal of the Balkan Tribological Association

Cycloidal speed reducers belong to the new generation of mechanical gears. Cycloidal speed reducers are increasingly used in modern engineering due to their good performances. Friction exists at all points of contact between the moving elements of cycloidal speed reducers, as one of the main causes of power losses in power transmission. In this paper, the friction of the contact of cycloid disc and housing rollers has been taken into account, while the friction at the contact of cycloid disc and output rollers, and at the contact of cycloid disc and central roller bearings are neglected. The effect of friction on the distribution of contact force, the friction torque value is analysed as well as efficiency. This paper presents 2 analytical models for calculating the values of contact force and friction torque. The 2nd model opposed to the 1st, taking into account the phenomenon of friction. The results showed that friction significantly affects the distribution of normal force. Increase of the friction produces the contact forces and friction torque increase, also, while efficiency is decreasing.

The influence of the cycloid disc bearing type on the cycloidal speed reducer efficiency

MATEC Web of Conferences, 2021

The robotics industry has experienced a rapid expansion in the last decade. As a result, the market of speed reducers with high gear ratios, high precision and a compact design is growing rapidly. In addition to these characteristics, it is very important for gear trains to have high efficiency. Because of their compact design, cycloidal speed reducers are not exposed to axial forces, which is their important characteristic. This means that radial bearings can be used in their supports. The bearing type has significant effects not only on the design and dimensions of the cycloid speed reducer but also on its efficiency. In this paper, an analysis of power losses for different types of rolling bearings of a cycloid disc has been performed. At the end of the paper, concrete conclusions are presented as well as directions for future research.

Determining efficiency of cycloid reducers using different calculation methods

MATEC Web of Conferences

Cycloid reducers are gear trains which can be classified as planetary transmissions. These transmissions have a very wide range of uses in industry in transporters, robots, satellites, etc. This research presents a comparative analysis of three analytical methods for determining cycloid drive efficiency. The paper explores every mathematically formulated method and compares them to experimental results from literature. The presented methods for determining efficiency have a common property, in that they all determine losses due to friction on the bearing cam surface of the shaft, the rollers of the central gear and the output rollers. The calculation of efficiency values is done for standard power values. The methods differ primarily in the way they calculate losses. For each method of calculating efficiency there is an analysis of pros and cons. The paper concludes with suggestions as well as possible directions for further research.

Efficiency of non-pin wheel cycloid reducer concept

Efficiency of non-pin wheel cycloid reducer concept, 2022

Defining new concepts is of vital importance for the further development of cycloid reducers, which are increasingly used in industry. In order to reduce shock loads, backslash, noise, vibrations, and production costs, a new, non-pin wheel concept was developed. However, the use of stationary circular segments instead of rotating ring gear rollers significantly affects the amount of friction. Therefore, this paper aims to analyze the power losses in the contacts of elements of the non-pin wheel cycloid reducer concept. The test was made for different sizes of cycloid reducers, and one of the most acceptable models proposed by Malhotra was used to determine the non-pin wheel concept efficiency. For the calculation of the forces occurring on the basic components, the assumption that it is an ideal meshing case was used. The simulation results show that the greatest power losses occur precisely in the contact between the teeth of the cycloid disc and the stationary circular segments, where sliding friction is dominant.

Cycloidal Geartrain In-Use Efficiency Study

Volume 5B: 42nd Mechanisms and Robotics Conference, 2018

Currently, harmonic drives are the primary speed reducer for robotic applications where a high reduction in a small package is required. Cycloidal drives are an alternative option for high reduction, small package, use-cases with the advantage of a higher specific torque and the ability to customize and integrate the drive for the application. These compact style cycloidal drives have been well studied in theory and simulation for their performance, but very little data is available on their actual performance over time. This paper presents experimental data on performance of a cycloidal drive designed for a Lunar or Martian rover application. Burn-in time efficiency curves and torque/speed efficiency profiles are computed after running the drive through 129k output cycles (7.6M input cycles) over the course of 300+ hours of testing. The study finds that substantial burn-in time may be required for steady-state performance, but peak efficiencies of 81% can be achieved. Also, the eff...