﻿ Mechanism | Add Bevel Gear-Pair

# Mechanism | Add Bevel Gear-Pair

### What is a Bevel Gear-Pair?

A Bevel Gear-Pair is two Gears that rotate in mesh, with each gear on a different intersecting Plane.

Gear-1 has a motion that is defined before you add the Bevel Gear-Pair.

The motion of Gear-2 is a function of the gear ratio.

The gears may have an external or an internal mesh.

We use the same command to add a Bevel Gear-Pair. as we use to add a Gear-Pair

### Prepare Bevel Gear-Pair

The preparation to add a Bevel Gear-Pair is more complex than Add Gear-Pair.

A Bevel Gear-Pair relates three Lines in three Parts.

Two Parts are in one Mechanism-Editor. The third Part is in a different Mechanism-Editor.

The Mechanism-Planes of the two Mechanism-Editors must intersect. They are typically, but not necessarily, 'orthogonal'.

Notes:

 • Green Part-Outline - kinematically-defined Part - Solved-Part - are terms for a Part that has its motion already defined.
 • Blue Part-Outline - kinematically-undefined Part - Free-Part - are terms for a Part that does not have its motion defined.

Preparation 1: Add a Rotating Part

 • A Pin-Joint joins a Point in Line joins a Point in Line in a different Part - usually the Base-Part. The two Parts have Green Part-Outlines
 • Line : add a dimension to define its length, with the Part-Editor.

Note: It is not necessary that the motion of the rotating-Part is defined with a Motion-Dimension FB.

Preparation 2: Add a Plane to the Line in the Base-Part

 2 Click the Line in the Base-Part
 • In the Add Plane dialog:
 1 Click the 'Move Plane to end-Point' check-box
 2 Enter 90º in the Rotate around the Z-axis
 3 Enter 90º [default value] is in Rotate around the x-axis.

The new Plane
Notice the Blue and Red Arrowheads

Preparation 3: Add a Mechanism-Editor to the new Plane

 1 Click Model toolbar >Add Mechanism-Editor
 2 Click the new Plane

You will 'jump' to the new Mechanism-Editor

 1 Click Visibility toolbar> Show Part-Outlines in other Mechanisms
 2 Spin the model to show the Part-Outlines and the sketch-elements in the two Mechanisms

Preparation 4: Add a new Part and Pin-Joint

 1 Click and do Kinematic elements toolbar > Add Part
 2 Click Kinematic elements toolbar > Add Pin-Joint
 a. Click the Origin of the new Part
 b. Click the Point at the end of the Line in the 'other Mechanism'

The Part will 'jump' to a new place, that I cannot predict! Do not be concerned to where the Part moves. It has a Blue Part-Outline.

 3 Click the original Mechanism-Editor

Do the Preparation - see above.

Make sure the active Mechanism-Editor includes the rotating-Part with the Green Part-Outline

Make sure to Visibility toolbar > Show other Part-Outlines and sketches

 STEP 1: Click Machine elements toolbar > Add Gear Pair

The Command-Manager instruction is:

 Add Gears: DriveR Gear is Green Part; DriveN Gear is Blue Part. Parts joined to Green Line with Pin-Joints.

The four elements to click to add the Bevel Gear-Pair:

The Line along the centre of the rotating-Part with the Green Part-Outline

The Line along the centre of the Part in the 'other Mechanism'

The Line in Base-Part

The dimension that defines the length of the Line

Referring to the hints in the Command-Manager and the elements 1 - 4  in the image above:

 STEP 1: Green Line on Gear Part 1

The CAD-Line along the kinematically-defined Part. This Part has a Green Part-Outline.

 STEP 2: Blue Line on Gear Part 2

The CAD-Line in the Part in the other Mechanism-Editor. It is not yet a kinematically-defined Part. This Part has a Blue Part-Outline.

 STEP 3: Green Line joining Gear Centers

The Line is in the Base-Part to which Gear Part 1 is joined with a Pin-Joint. The Base-Part has a Green Part-Outline

The Part-Editor opens to show the dimension for the length of the Line.

 STEP 4: Centre Distance Dimension

Click the arrowhead, or the dimension line , that defines the length of Line

The command will not complete if you click the Line or the Dimension-Value, will not work.

 STEP 5: Click in the Command-Manager.
 • The distance between the Gear-Centres is a function of the number-of-teeth, module and mesh of the gears.
 • The default Bevel Gear-Pair elements have an external mesh.
 • All the Parts are now kinematically-defined Parts.
 • The Gear Part 2 is now identified in the Kinematics-Tree as a Geared-Rocker

to edit the gear parameters

Tutorial and Reference Help Files for MechDesigner and MotionDesigner 13.2 + © Machine, Mechanism, Motion and Cam Design Software by PSMotion Ltd