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Gear Measurement

Calculation of the diameter of measuring pins dM for the worm and the diameter of measuring balls dB for wormwheel. Input of rounded values for this diameters, but they have to be as close as possible to the calculated values.

The application calculates: mean normal chordal thickness with tolerance in ± notation, diametral dimension over three pins Md1 for the worm, diametral dimension over two balls Md2 for wormwheel with respective tolerance. The backlash to exspect is also calculated. The the measuremnt sheet is to compose with options to select with check boxes. A composition can be stored as default for the next calculations.

Materials for worm and wormwheels

The application provides a dialog box for management of materials for gears. According the standard ISO 6336-5 the endurance contact stress values and endurance bending stress values can be determined in function of the tooth flank hardness using an equation of straight line σH,F = Ax + B where x stands for the flank hardness, A for the slope coefficient and B for the segment on the y-axis. The data for wormwheel materials are derived from the text book Niemann-Winter Maschinenelemente Band III. Input for a worm gear pair requires input of material separately for worm and wormwheel, the material quality grade and the hardness of tooth flank. With the equation of the straight line the endurance contact stress value σHlim and the endurance bending stress value σFlim are determined in function of the tooth flank hardness.


Input of the load can be done with one of the following combinations:

  • Power at worm P1 and rotational speed of worm n1
  • Torque at worm T1 and rotational speed of worm n1
  • Torque at wormwheel T2 and rotational speed of wormwheel n2

Input with dialog:

Load Input Dialog

Bearing Points

Input of location of bearing points A and B and mesh point X with cylindrical coordinates as presented in following dialog box:

Bearing Points Dialog Box

Worm Gear Forces

Calculation of transverse tangential force Ft, the radial force Fr and the axial force Fx in the mesh point and the reaction forces in the supports. Self locking is checked by the application. Calculation results are presented in a table as shown in following window for example:

Output of Forces

The calculation results may also be exported in a text- or a html file. To have a look on a complete forces calculation report, click on Calculation Report Forces to open it in a blank page.

Go to next web page for load carrying capacity.