Matsumoto Y.,Oriental Motor Co.
Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C | Year: 2013
In this paper, we analyzed the mechanical loss factor of a geared motor, which is composed of a 90W induction motor and a parallel gear reducer with total reduction ratio 9 and 18. Gear mesh was lubricated with the grease of NLGI consistency number 2. The loss factor was evaluated as the sum of load independent part, or at no loading, and load dependent part. The loss of oil seal and grease was examined by the measurement of the geared motor at no loading. The friction loss of bearing was evaluated in terms of the coefficient of friction of bearing, which was measured by the unit testing of bearings. Change by a temperature of the loss of grease was measured by the experiment. And the friction loss of tooth flank was decided as the residual value after subtracting other losses obtained value from the experiments. The result shows that the loss at no loading holds the higher proportion of loss, due to the oil seal and the grease. When load was applied, the portion of the loss of tooth flank increased. The mean friction coefficient of a tooth flank by grease lubrication proved to be a representative value of 0.12, which was verified the gear reducer of the difference dimension. © 2013 The Japan Society of Mechanical Engineers.
Matsumoto Y.,Oriental Motor Co.
Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C | Year: 2012
In this paper, we evaluated the mechanical loss of the geared motor, which consists of an induction motor with a rated power of 90W and a two or three staged parallel gear reducer. The result shows that the total loss torque was composed of a constant amount of loss at no loading, or the torque independent part, and the frictional loss which was proportional to load torque. The loss at no loading, which is the internal loss of gear reducer part, greatly contributes to the total loss. It was confirmed that the loss torque hardly depends on the speed due to a trade off between an increase in loss with rotational speed and a decrease in viscosity of the base oil due to a temperature rise. While the gears were lubricated with lithium grease, churning loss was not observed since any excess grease was squeezed out from the region to be lubricated. Furthermore, grease lubrication had less loss at the tooth mesh region than oil lubrication, which provided more attachment on the tooth surface. © 2012 The Japan Society of Mechanical Engineers.
Matsumoto Y.,Oriental Motor Co. |
Houjoh H.,Tokyo Institute of Technology
Proceedings of the ASME Design Engineering Technical Conference | Year: 2015
In a previous study, we analyzed the mechanical loss factors of a small-sized geared motor comprising an induction motor and a parallel gear reducer. The load dependent loss is mainly caused by gear mesh friction, which is related to grease characteristics. This study investigates how the grease characteristics influence the friction loss of the gear mesh. The important grease characteristics are the cone penetration, kinematic viscosity, type of base oil, and type of thickener. The loss of gear mesh friction was evaluated in terms of the average friction coefficient between the gear teeth and was found to be unrelated to the cone penetration and kinematic viscosity of the base oil. The average friction coefficient of grease combined with lithium soap/poly urea and mineral base oil was 0.09-0.11; when combined with aluminum complex soap and synthetic base oil, the friction coefficient reduced to 0.07-0.08. © Copyright 2015 by ASME.
Uchimura Y.,Shibaura Institute of Technology |
Saito Y.,Oriental Motor Co.
IEEJ Transactions on Industry Applications | Year: 2014
This paper proposes a control method that attenuates adverse effects due to cogging torque on the vibratory system. A conventional controller utilizes a disturbance observer to estimate the cogging torque; however, the observer usesa filter that causes an estimation delay. If the cut off frequency is high enough, the delay may be negligible, but the estimated disturbance (cogging torque) will be contaminated with vibration. Instead, the proposed method uses a filter with a low cut off frequency; the estimation delay is compensated for by the leading angle, then it is used to attenuate the disturbance in the next rotational duration. The experimental results showed that the proposed method was clearly superior: the RMS magnitudes of the velocity control error were drastically reduced. © 2014 The Institute of Electrical Engineers of Japan.
Oriental Motor Co. | Date: 2012-10-09
This detection device is configured from a gear mechanism (