Gear Ratio in Mechanisms - Essay Example

Essay - mechanical engineering: Gear ratios Introduction Gears refers to a set of toothed wheels that work together to alter the relationship between the speed of a driving mechanism such as a vehicle or generator engine and the speed of the driving parts of the machine such as wheels or rollers. Gears are used as transmitters of motion. The history of gears dates back to ancient Greeks who are associated with discoveries first machines. Of late, the modern mechanization has engaged the use of gears in relatively all machines. Gears have been used in machines to impact motion and change the direction. The gears in a locomotive engine accelerate or reduce the speed of the machine. Gears are also used to make work easier- a simple gear system can be devised to lift or move heavy weights (Gallagher, 2006). This is achieved through proper combination of the gear ratio. Gear ratio refers to the ratio in the angular velocity of the input gear and the output gear, which is brought about by the difference in the number of teeth between the two gears. The aspect of variation in motions within a gear system is brought about by the difference in the number of teeth within the involved gears. Equipment and Materials A combination of a gear kit and motor can be used to make a lifting machine. This involves materials like motor, battery, circuit, six gears and two sprockets. The six gears should be of varied teeth. The battery is used as the motive power to provide energy to run the motor. The connection between the motor and the battery is enhanced by circuit, which is a combination of electrical wires. The gears should be connected to each other through the sprockets, with the gears with many teeth directly connected to the motor. When the motor rotates by the impulse of electricity, the motion is impacted on the gear systems, whose motion is increased with the variation of the number of teeth in the gears (Gallagher, 2006). The increase in motion from the motor through the gearbox to the lifting lever leads to increased output which leads to a resultant force lifting an object. The complete machine should include a battery connected to a DC motor by electricity wires-probably made of copper, the motor connected to the gear system by use of the sprocket and the gear system connected to the lifting system by the output sprocket. Methods and Results: The lifting of the weights is indirectly proportional to the number of gears used, and sizes of their sprockets. Use of large gears will enhance little motion and lifting of little weight while the use of small gears brings about a greater force. A gear with small one sprocket will provide a resultant force capable of lifting an approximated weight of 50grams. The more the gears, the more the resultant force hence the heavier the weight the system can lift. A combination of the six gears, with a small sprocket provides a resultant force that can lift about 51200grams. The advantage of this is put into practice to make the machine more effective. Discussion of Results: Gear ratio refers to the ratio in the angular velocity of the input gear and the output gear, which is brought about by the difference in the number of teeth between the two gears. A combination of small and large sprockets increases the gear ration, which relatively increase the resultant output. Torque refers to the wisting force resulting from the motion of the gears and the sprocket. The lifting effect of the machine will be enhanced by the torque. The torque will vary with the amount of weight mounted on the machine. In a case of the machine with six small gears and small sprocket lifting a small weight like 3200grams, torque will be higher compared to the same machine lifting the expected maximum weight of 51200grams. Higher gear ratio will enable the machine lift heavier weights. Little gear ratio makes the machine ineffective hence cannot lift heavier weights due to little torque. In the case of the lifting machine, a relatively higher gear ratio is required for the efficiency of the machine. The size of the sprocket also impacts on the lifting force of the machine. If the machine uses a larger size of sprocket, the torque will be little and hence it won’t be in a position to lift a relatively heavier load. A small sprocket will result into a relatively higher torque which will be in a position to lift a heavier load. In this experiment, the system used a gear ratio of 4:1. However, this effect was not consistent. There was variation of the effects brought about by the ratio. This difference was caused by the variation in the number of gears involved in the system. The size of the sprocket is again not consistent hence the impact of the whole system is varied. Use of the six gears, with the ratio of 3:1 gives the most reliable results of a relatively higher force capable of lifting 51200grams. The impact of the machine and its resultant output can also be affected by the motion of the motor (Gallagher, 2006). Relatively higher speed of the motor is likely to bring about higher torque and hence increasing the expected lifting force, capable of lifting heavier loads. This speed will be affected by the current connected to the motor. Higher direct current - DC induced to the motor will increase its momentum and therefore make the gear rotation faster. A relatively low Direct current makes the motor to rotate slowly, and relatively the rotation of gears will be slow. This reduces the resultant force of lifting the load. However, the machine may not provide consistent results. This variation may be brought about by a combination of factors. For instance, friction within the gears will reduce its efficiency (Calabrese, 2003). The friction force will oppose the rotation of the gears and the sprocket hence may not provide consistent results. The current will also bring about the inconsistent results. When the batteries are used consistently, there is reduction in current follow. The ability of the machine to lift the expected weight will depreciate relatively with time due to reduced power, which reduces the rate and speed of motor rotation. Other mechanical problems within the machine will also affect its efficiency. The rotation frequency of the motor will also have a direct impact to its workability. A mechanism using a motor with high frequency increases the rotation speed and the torque hence leading to a direct impact on the ability of the machine to lift heavier loads. Use of varied circuits and a varied lever system will interfere with the expected results. Conclusion This is an automatic machine that works by back-front torque. It makes use of electrical energy to impact force and motion on the gear system through the motor. The electricity rotates the motor which in turn rotates the gears. The rotation of the gears though a winch system improvisation enables lifting of the load mounted at the other end of the system. The simple system works on the principle of motor and gears. The efficiency of the machine is determined by a number of principles and factors such as the gear ration and the motive power impacted on the motor by the battery. Higher gear ratio will be in a position to make the machine lift heavier weights compared to a lower gear ratio (Calabrese, 2003). The increase in DC within the circuit will also increase the rotation frequency of the motor hence increasing the torque. Increase in the torque will make the machine capable of lifting heavier loads. However, the efficiency of the machine is affected by other factors such as friction within the gears. Constant greasing should be encouraged to keep the machine effective. The current supply should also be set constant to give progressively similar results (Ollerenshaw, Triggs & Millard, 1994). However, the wear and tear of the gear system may also impact on such regardless of all the above measures. References Calabrese, S. R. (2003). Practical controls a guide to mechanical systems. Lilburn, GA, Fairmont Press. Gallagher, K. S. (2006). China shifts gears automakers, oil, pollution, and development. Cambridge, Mass. MIT Press. Ollerenshaw, C., Triggs, P., & Millard, P. (1994). Gears. Milwaukee, Gareth Stevens Pub. Read More