著者
堀 光平 林 巌
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集 C編 (ISSN:03875024)
巻号頁・発行日
vol.60, no.579, pp.3940-3947, 1994-11-25 (Released:2008-02-26)
参考文献数
10
被引用文献数
1 1

Mechanical paradox planetary gears are suitable for power transmissions of current robots, such as space manipulators, which drive large-inertia loads, because the gears offer high reduction ratio, small size, light weight and high reliability. However, mechanical paradox planetary gears are subject to a drawback in that their efficiencies are lower than those of conventional planetary gears. The efficiencies of mechanical paradox planetary gears are hence theoretically analyzed and evaluated by defining the tooth number modification of a planet gear to deal with all the possible combinations of tooth numbers. The following results are obtained : the efficiencies are greatly influenced by the efficiencies of the planet and internal gear pairs ; the maximum efficiencies are minimally influenced by the reduction ratio, and they are obtained when the factors of the contact ratio of the gear pairs are approximately equal ; the maximum efficiency is approximately 78% if the tooth surface friction coefficients are 0.1.
著者
堀 光平 林 巌
出版者
一般社団法人日本機械学会
雑誌
日本機械学會論文集. C編 (ISSN:03875024)
巻号頁・発行日
vol.60, no.579, pp.3940-3947, 1994-11-25
被引用文献数
6

Mechanical paradox planetary gears are suitable for power transmissions of current robots, such as space manipulators, which drive large-inertia loads, because the gears offer high reduction ratio, small size, light weight and high reliability. However, mechanical paradox planetary gears are subject to a drawback in that their efficiencies are lower than those of conventional planetary gears. The efficiencies of mechanical paradox planetary gears are hence theoretically analyzed and evaluated by defining the tooth number modification of a planet gear to deal with all the possible combinations of tooth numbers. The following results are obtained : the efficiencies are greatly influenced by the efficiencies of the planet and internal gear pairs ; the maximum efficiencies are minimally influenced by the reduction ratio, and they are obtained when the factors of the contact ratio of the gear pairs are approximately equal ; the maximum efficiency is approximately 78% if the tooth surface friction coefficients are 0.1.
著者
堀 光平 林 巖
出版者
一般社団法人日本機械学会
雑誌
日本機械学會論文集. C編 (ISSN:03875024)
巻号頁・発行日
vol.62, no.596, pp.1548-1555, 1996-04-25
被引用文献数
6

To improve the efficiency of 3K-type mechanical paradox planetary gear drive, a new design method called the approach-and recess-contact ratio equalization method is proposed and described. The concept of this method is to satisfy the coaxial condition of the rotatory- and fixed-internal gear pairs, which have a large influence on the efficiency of the gear drive, and simultaneously to maximize their efficiency. For this purpose, first the contact ratios of the two internal gear pairs are given ; second, their profile-shift coefficients are determined so that the coaxial condition can be satisfied ; then, the diameters of their addendum circles are determined so that their approach- and recess-contact ratios can be equalized. The efficiency of the gear drive obtained by this design method is theoretically calculated under the assumption that the tooth surface frictional coefficients are all 0.1. Consequently, the maximum efficiency of 86.1% is obtained on a gear drive with a reduction ratio of 1/351 and a contact ratio of 1.2. This obtained efficiency is higher by 12% and 8% than the efficiencies of 74% and 78%, obtained by the conventional design method without and with profile-shift coefficient optimization, respectively.