Add Bevel Gear-Pair

see also: Gear-Pair dialog-box

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.

Add Bevel Gear-Pair command

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

R13 -Icon Add Gear-Pair

Machine Elements Toolbar : Add Gear-Pair

Menu :

Add menu > Mechanism sub-menu > Add Gear-Pair

Edit Gear-Pair :

Gear-Pair dialog-box

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'.

Lines or CAD-Lines.


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-Joint2s joins a Point in Line1s-red joins a Point in Line3s in a different Part - usually the Base-Part. The two Parts have Green Part-Outlines
Line3s : 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.

See Globe-www Tutorial 1: Add a Rotating-Part.

Add Plane dialog

Add Plane dialog

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

1.Click Model menu [or toolbar] > Add Plane
2.Click the Line3s 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.
Plane to a Line

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 Plane4s

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

See also:

Geared-Rocker, Dyads and Kinematics-Tree.

Add Bevel Gear-Pair command

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:

1s The Line along the centre of the rotating-Part with the Green Part-Outline

2s The Line along the centre of the Part in the 'other Mechanism'

3s The Line in Base-Part

4s 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-Line1s-red along the kinematically-defined Part. This Part has a Green Part-Outline.

STEP 2: Blue Line on Gear Part 2

The CAD-Line2s 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 Line3s.

STEP 4: Centre Distance Dimension 4s

Click the arrowhead, or the dimension line4s , that defines the length of Line3s

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



STEP 5: Click OK-tiny-11-15 in the Command-Manager. 4s
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

See Gear-Pair dialog-box 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