The invention relates to methods of using amphibious and ground effect vehicles that incorporate a wheel having a box portion affixed to a disc or wheel portion such that a vehicle with such wheels can roll on most surfaces and easily transition from one type of terrain, or medium, to another.

The invention relates to methods of using amphibious and ground effect vehicles that incorporate a wheel having a box portion affixed to a disc or wheel portion such that a vehicle with such wheels can roll on most surfaces and easily transition from one type of terrain, or medium, to another.

Disclosed herein are permanent magnetic AC machine direct-drive resonant flapper system for flapping wing micro air vehicles and flapping fin autonomous underwater vehicles.

The invention relates to amphibious and ground affect vehicles. The invention incorporates a special wheel consisting of a box portion affixed to a disc or wheel portion. A vehicle with such wheels can roll on most surfaces with easy transition from one medium to another. For example, it can roll from the terrain, onto the water and then back to the land. Such wheels enable vehicles to roll on top of the snow and other surfaces where conventional wheels cannot.

The invention relates to amphibious and ground affect vehicles. The invention incorporates a special wheel consisting of a box portion affixed to a disc or wheel portion. A vehicle with such wheels can roll on most surfaces with easy transition from one medium to another. For example, it can roll from the terrain, onto the water and then back to the land. Such wheels enable vehicles to roll on top of the snow and other surfaces where conventional wheels cannot.

Provided is a ship propelling apparatus including a rotation shaft on which a rear propeller is fixed; a front propeller rotatably supported on the rotation shaft in front of the rear propeller; and a counter-rotating device through which the rotation shaft passes, which includes a gear box including therein a plurality of gears configured to reverse rotation of the rotation shaft and transfer the reversed rotation to the front propeller, and which is installed in an installation space formed at the rear of a ship. The rotation shaft includes a measurement hole formed to pass through a center of the rotation shaft for centering of the counter-rotating device installed in the installation space; and an individual lubricant path separated from the measurement hole.

Provided is a ship propelling apparatus including a rotation shaft on which a rear propeller is fixed; a front propeller rotatably supported on the rotation shaft in front of the rear propeller; and a counter-rotating device through which the rotation shaft passes, which includes a gear box including therein a plurality of gears configured to reverse rotation of the rotation shaft and transfer the reversed rotation to the front propeller, and which is installed in an installation space formed at the rear of a ship. The rotation shaft includes a measurement hole formed to pass through a center of the rotation shaft for centering of the counter-rotating device installed in the installation space; and an individual lubricant path separated from the measurement hole.

A bicycle and board apparatus comprising a buoyant board, a front wheel, a rear wheel and a steering member, and being mountable and usable in a first configuration as a bicycle in which the buoyant board is the bicycle's frame and in a second configuration as a surfboard by changing the orientation of the front wheel, the rear wheel or the steering member with respect to the buoyant board.

A bicycle and board apparatus comprising a buoyant board, a front wheel, a rear wheel and a steering member, and being mountable and usable in a first configuration as a bicycle in which the buoyant board is the bicycle's frame and in a second configuration as a surfboard by changing the orientation of the front wheel, the rear wheel or the steering member with respect to the buoyant board.

A cyclorotor is described that can be used as a propulsor for a marine vessel. The cyclorotor includes a rotary housing comprising a main body and a plurality of blade modules arranged circumferentially around the main body. The cyclorotor also includes a plurality of blade assemblies, each blade assembly being located in a respective blade module and having a blade extending from the rotary housing with a blade axis about which it can be pivoted relative to the rotary housing. Each blade assembly is associated with a blade actuator comprising an electric motor and having a drive shaft, a driving gear mechanically connected to the drive shaft and a driven gear mechanically connected to the respective blade assembly for pivoting the respective blade about its blade axis. Each blade module is preferably adapted to be detached and removed from the main body.