| dc.description.abstract | In rotating machinery, torque is transmitted from shafts to coupling hubs (or vice versa) through keys, friction, or a combination of the two. As a rule; coupling hubs must be installed on shafts with a certain amount of interference. This interference has two purposes: to prevent rocking of the hub on the shaft, and to help in the torque transmission. With sufficient interference all the torque can be transmitted by friction, and keys can be eliminated. Interference has two disadvantages: it makes installation difficult, and hub removal even more difficult. Hydraulic methods of hub removal are discussed. These methods are sound, make for easy and quick hub removal, and are safe. Some engineers are reluctant to use hydraulic removal for two reasons: it requires specialized tools and better training of mechanics, and it was known to be potentially dangerous. As any new and sophisticated procedure, it also received a bad name from early failures, all caused by misuse. The following topics are discussed: • Torque transmission through keys • Installation of keyed hubs using interference • Torque transmission through friction • Installation of keyless hubs, heat-assisted installation, hydraulic assisted installation • Hydraulic removal of hubs, dismounting keyed hubs, dismounting keyless hubs • Failure cases. Hydraulic methods for hub removal were discussed in previous papers [1, 2]. The purpose herein is to compile and update previous information, and to describe good practices. | en |
