![]() "Calculation for a single stage gear is easy even if the number of meshing gears increases !"ĥ. Therefore, the rotational number of gear E is calculated as follows: If several gears mesh in a single stage gear, the rotational number is determined by the numbers of teeth of the input and the output gears regardless of the number of gears and teeth in the middle. (Figure 2-8)įigure 2-8: Speed ratio calculation of a single stage gear These calculations become increasingly cumbersome as the number of gears increases. Rotational direction of the drive gear: CCWįigure 2-7: Exercise problem for speed ratio of a single stage gear (3) Rotational number of the drive gear: N A=90rpm Rotational number of gears depend completely on the number of teeth of meshing gears and is transmitted as calculated.Ī gear train that meshes in the same plane is called a “single stage gear” and the following formulas apply: (Figure 2-4) Speed ratio calculation of a single stage gear train (Figure 2-3)įigure 2-3 : Mechanism of geared motor 4. Geared motor is an electrical part consisting of a small motor and a gear box to produce larger torque rather than to lower the motor’s rotational speed. Many geared motors are used in automotive parts, home appliances, and motors of industrial machines. (This point will be explained in the next chapter.) Therefore, the speed of a small output power of a motor is decreased with gears to produce larger torque in most cases. The torque becomes smaller when increasing speed and becomes larger when decreasing. The rotational speed of the output shaft is decreased, increased or made the same compared to that of the input shaft depending on the purpose of the application. The aim of mechanism design with gears is to acquire the necessary rotational number by combining several gears. Speed ratio (speed increasing / decreasing ratio) "CW and CCW are frequently appearing words in mechatronics product development and, therefore, important for you to remember !"ģ. Therefore, viewing directions need to be consistent when showing mechanism movement with pictures (Figure 2-2).įigure 2-2: Definition of the rotational direction of gears as seen from a predetermined viewing direction Unlike motors, the rotational direction of gears can be defined differently depending on the viewing direction. Mechanical design engineers need to convey information about a motor’s rotational direction to electric design engineers and software design engineers. (Figure 2-1)īy the way, the spin to the right is commonly abbreviated as CW (clockwise) while the spin to the left as CCW (counterclockwise).įigure 2-1: Definition of the rotational direction of the motor Rotational direction of the motor is defined by the rotation of the shaft as seen from the side the motor shaft projects out. Generally, a motor is used as the power source when using gears in designing mechanisms of mechatronics products. Let me explain this with commonly used cylindrical gears. You can change the directions and the number of rotations of the input and output shafts by meshing several gears. (Table 2-1)Ĭhange rotational direction (clockwise / counterclockwise)Ĭhange the number of rotations (speed up / down)Ĭhange turning force (increase / decrease torque) Here is the list of gear functions for mechanism designs. Know about rotational directions and numbers of rotation of gears.The first step of mechanism design using gears.Notice also that rotation direction is irrelevant because the same voltage (amplitude and polarity) will be produced when the wire moves downwards through the magnetic field irrespective of whether it takes a counter clockwise or clockwise route. ![]() If CD is moving down through the magnetic field and is beginning this process at the top (as shown in the OP's diagram), then a voltage is induced that pushes current in the direction D to C (note that N and S are in opposite places on my diagram to the OP's). The polarity of the conductor 'CD' on its terminnal? If the conductor CD rotates in counterclockwise direction what will be So that's the currents but what drives that current? An induced voltage drives the current and that has a polarity that must reverse direction to drive current in the opposite direction. This means your middle finger (current) is pointing outwards from the page. Now, if the force was downwards you would have to rotate your hand through 180 degrees to keep the field in the same direction but now your thumb (movement) would be pointing down. So, if the conductor is moving upwards (as shown), Fleming's right hand rule tells us that current will flow into the page (as shown): -Īlign your hand so that your index finger is pointing left to right to correspond with the field line directions of north to south in the top picture. ![]() Just consider a single conductor connected to an ammeter:. ![]()
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