An UAV with Twin Propellers Driven by Single Motor

As the technology is looping and far applications of UAV is improving so there is need to develop an UAV with optimum propulsive efficiency and also producing high thrust. So our mission is to build an UAV with twin propellers propelled by single motor. A fixed wing UAV which has a unique type of propulsion system. In this fixed wing UAV, two propellers are driven by single motor to enhance the propulsive efficiency. The bevel gear mechanism is the most important. This is the propulsion system for the aircraft model which runs the two propellers with a single motor. Bevel gears are used to transfer the power from the motor to the propeller. The bevel gear train is 80cm long through which a long shaft is passed that holds the bevel gears. Totally six bevel gears are housed inside the box which connects the motor shaft to the propeller shaft. The bevel gears are arranged in such a way that the when motor shaft rotates the propeller connected rotates both in opposite direction.

The Synthesis of a Transmission With Intersecting Axes for Rectifying and Reducing a Periodic Speed: A Preliminary Study

In power-transmission tasks, the mechanical designer faces sometimes the problem of transmitting a constant angular velocity from a shaft at the output of a motor to another shaft connected to the load. When the first shaft is connected to the rotor of the motor via a gear box directly, and the motor is supplied with an effective speed control system, then the problem of power transmission can be readily solved using a spur-gear train if the shafts are parallel; a bevel-gear train if the two shafts intersect; and a gear train with skew axes if the shafts are neither parallel nor intersecting. However, instances occur in practice whereby the rotor of the motor is connected to a speed reducer that does not preserve the constancy of the motor speed, e.g., when a sprocket-chain transmission is used. In these cases, the input speed is not constant, but periodic. This paper focuses on the design of a transmission mechanism that serves to rectify the periodic speed of an input shaft to deliver a constant speed to the load. Moreover, in doing this, we show that it is possible to reduce the speed delivered by the motor as well. The problem of power transmission between parallel axes was reported in an earlier paper. Here, we report work on the corresponding problem when the shafts intersect. In the two cases, a transmission based on cams is synthesised, this paper reporting on a design based on spherical cams.