Abstract:
The present invention relates to a mechanical element, and more particularly, to a crank connected to a bicycle pedal or a handle for rotating a rotary body and to a bicycle using the same. The present invention uses a cylindrical cam, an end cam, or a swash plate cam, and the shafts of these cams and a shaft of a pedal or a handle for applying force are equipped with a miter gear (a bevel gear the number of teeth of which is 1:1 and the shaft angle of which is 90 degrees), such that the crank retracts/extends one time per one rotation of the pedal or the handle. The retractable/extendable crank of the present invention is advantageous in that the length of the crank is elongated to generate a large amount of rotating force in a force-applying section, and shortened in a section where no force is applied to reduce the actuating space occupied by the crank and apply a large amount of torque to the rotary body from the same force, without deviating from the normal motion range of the arms or legs during rotation. The retractable/extendable crank of the present invention has a significantly rigid structure and provides reliable operation, and thus is suitable as a driving crank to be connected to a pedal of a bicycle. As compared with conventional bicycles, the bicycle using the crank of the present invention is supplied with a larger amount of rotating force in proportion to the elongation of the crank from the same force, thus enabling the bicycle of the present invention to travel quickly with less force and climb a steep upward slope in an easy manner.
Abstract:
The present invention relates to mechanical equipment, more specifically, a continuously variable transmission that can change the speed of a driving shaft power to a random rotational speed and transmit same to a driven shaft thereby. The continuously variable transmission of the present invention comprises: a driving disk (1) that couples to the shaft of a power device and provides power while rotating thereby; a driven disk (2) that receives the power from the driving disk; a vibrating belt (3), which is a chain or a belt that winds between the driving disk (1) and the driven disk (2) and transmits power thereby; and a tensioner (4) for maintaining the tension of the vibrating belt (3). The continuously variable transmission of the present invention uses a variable disk for either one or both of the driving disk (1) and the driven disk (2). The variable disk is provided with a plurality of movement wheels placed radially to have an equal belt rotation radius from the driving shaft, wherein the rotational radius of the belt changes according to the required gear ratio. Each of the movement wheels are provided with a ratchet wheel on the shaft thereof, so that the movement wheels rotate in only one direction and do not rotate in the opposite direction. The continuously variable transmission of the present invention can obtain a very high gear ratio, and enables low-cost production through a much simpler configuration than that of a conventional transmission. Also, using the continuously variable transmission of the present invention on a vehicle enables the change of speed at the best gear ratio, based on various control variables such as the vehicle speed, the engine speed, and the engine output.
Abstract:
To accomplish the technical objective of the invention, a continuously variable transmission for a bicycle according to the present invention comprises: a driving disk (1) coupled to a pedal (P) shaft of a bicycle body (B) to provide power; a slave disk (2) coupled to a rear wheel (C) to receive power from the driving disk (1); a transmission belt (3), provided in the form of a chain or a belt wound between the driving disk (1) and the slave disk (2) to transmit power; and a tensioner (4) for maintaining the tension of the transmission belt (3). The continuously variable transmission for a bicycle that uses a variable disk according to the present invention may shift a gear within a significantly large transmission range, thus enabling the bicycle to travel at a high speed on a flat land, and to climb a steeply sloped road. In addition, the continuously variable transmission for a bicycle according to the present invention has no impacts during the shifting of gears, and enables the shifting of gears at a random transmission ratio.