CADFamily.com: KISSsoft Tutorial-Sizing a Planetary Gear Set for Precision Mechanics

1 Task

To size a planetary gear set with an input torque of 450 Nmm (0.45 Nm) at 10000 rpm. The nominal transmission ratio is 4.25. The required service life is 20,000 hours, with an application factor of KA=1.25.

The package size (external diameter of the gear rim) is 35 mm, including 3 mm material between the root diameter and the external diameter. The gears are made of sintered powdered metal. The module must be greater than 0.5 mm (due to manufacturing requirements). The tooth form must be optimized to make full use of the fact that the gears are not manufactured using the generation process. The calculation method used here is the one specified in AGMA: 210104-D04.

2 Starting KISSsoft

2.1 Starting the software

You can call KISSsoft as soon as the software has been installed and released. Usually you

start the program by clicking "Start?Program Files?KISSsoft03-2011KISSsoft". This opens

the following KISSsoft user interface:

Figure 2.1 KISSsoft main window

2.2 Starting the "Planetary gear" calculation module

In the "Modules tree"window, double-click the "Modules" tab to call the calculation for a "Planetary gear", see Figure 2.2.

Figure 2.2 Selecting the "Planetary gear" calculation module from the "Modules" window

2.3 Basic settings

If the AGMA 2101101 method is used for a planetary gear set, it is a good idea to activate the

graphical method for factor Y (as this influences the calculation of root stress). To do this, go to

the "Strength" tab, select "Details" and click the "Pair data" group. Activate the graphical method and define where the force is to be applied. As some of the solutions found during the draft design phase will have geometric errors (which cause KISSsoft to cancel the calculation automatically), we recommend you go to the module specific settings and activate "Allow large profile shift" and "Don't abort when geometry errors occur". This allows the KISSsoft software to continue with a calculation even if an error has occurred. See Figure 2.3.

Figure 2.3 "Define details of strength" and "Module specific settings" for this example

2.4 Setting constraints

Go to the "Geometry" tab and input the required number of planets (Figure 2.4). The load distribution coefficient K? increases the load placed on an individual planet. In this case, set it to 1.0.

Figure 2.5 Defining the load distribution coefficient

2.5 Rough sizing

Click [OK] to return to the main dialog. Open Rough sizing and specify the required calculation

method (1) and the material (2). Then input the application factor (3) and the service life (4). Click the radio button next to the Power field to define the load (5), see Figure 2.7.

Figure 2.6 Call the Rough sizing function

Figure 2.7 Setting the materials, calculation method, application factor and required service life

Specifying the load To specify the unit used for torque, click the right-hand mouse button on the appropriate field (Figure 2.8).

Figure 2.8 Specifying the unit for torque

Define the reference gear (1), the calculated value(2) (if the torque and number of rotations have been defined, the performance will be calculated) and input the data for the number of rotations and torque (3) (see Figure 2.9).