Gear AT Shape Definition allows you to create a property file (TLP) that defines the topology of a nut and spindle. Figure 313 shows how to access the tools you need to define your nut and spindle geometry.

The Gear AT Shape Definition has following tabs to help you design a gear

 

 

 

 

 

To define the gear, enter basic geometrical parameters in the General tab (Figure 314).

 

The Normal Module and the Number of Starts are the fundamental variables in defining a gear; the module is often standardized.

Angle describing the thread or helix slope on pitch cylinder in respect to plane perpendicular to screw axis, see Figure 315.

 

The value corresponds to the haft of the screw thread angle, see Figure 378. The angle is defined in axial plane.

 

Defines whether the helix is left handed (negative) or right handed (positive), Figure 315 shows right hand screw.

Screw length defines the distance between transversal planes on each sides of screw thread, Figure 317.

 

The rim diameter for an external gear and the bore diameter for an internal gear define the boundary of the gear rim (as solid and as finite element model) with the spindle nut body (Figure 318).

If bore or rim diameter are left to zero, the default is defined by Equation (5). Negative sign holds for external gear and positive sign holds for internal gear. However, the rim thickness should be in the range of (0.5, 1.5)m.

If user input is out of the range it is automatically adjusted and warning message is issued to the log file.

drim = droot +- m

 

Hit the button to open info window with the content of current *.TLP property file. The Preview Profile>> button opens the Profile plot window for the current property file as shown in Figure 319.

The Mass card of the Shape Definition process allows you to define the mass of the gear based either on the Geometry and Material Type or by specific User Input (Figure 320). In the former case the mass, center of mass and inertia tensor is computed later on by the mesher based on FE mesh volume. In the latter case enter all required data in current model units. In either case, inertia data are written to the *.TLP file.

 

The Profile tab defines the proportions of tooth profile which can be specified in axial plane. The profile parameters are defined in form of coefficient of Normal Modul. The Diameters informative fields show the resulting generating profile Proportions for quick check again data sheet values.