MechDesigner Reference & User Interface > 2.2 Mechanism-Editor > Mechanisms > Machine elements

Add Gear-Pair

Add Gear-Pair removes one(1) degree-of-freedom from a rotating-Part.

Terminology and definitions:

Gear-Wheel :	A rotating-Part with gear-teeth at a fixed diameter. The diameter is defined by the number and the module of the gear-teeth.
Gear-Pair :	Two inter-locking gear-wheels. Their teeth are in mesh. The angular velocity of each gear-wheel is related by the number-of-teeth on each gear-wheel, and the type of mesh.
Driving Part :	The rotating-Part that is kinematically-defined, and whose motion is defined (even if it is stationary) before you do Add Gear-Pair
Driven Part :	The rotating-Part whose motion is defined after you do Add Gear-Pair by the Driven-Part, the Number-of-Teeth on each Gear in the Gear-Pair, and the Mesh.
Gear-Mesh :	Inter-locking gear-teeth of a Gear-Pair transmit a torque and motion from one shaft to a different shaft.
External Mesh :	The gear-teeth of the two gear-wheels point outwards from their centers-of-rotation.
Internal Mesh :	The gear-teeth of one gear-wheel point inwards towards its center-of-rotation.
Simple Gear-Pair :	Two gear-wheels that rotate about two fixed centers.
Epicyclic Gear-Pair :	One gear-wheel orbits around the center of the other gear-wheel.

Prepare to do Add Gear-Pair

Simple Gear-Pair

MD-ADD-GEARPAIR-0

3 × Parts ; 3 × Lines ; 2 × Pin-Joints

Line and Line and Parts are kinematically-defined

Line and Part is not kinematically-defined

Lines are joined with Pin-Joints to each end of Line

Line has a dimension (in the Part-Editor)

Epicyclic Gear-Pairs

MD-ADD-GEARPAIR--EPI-0

3 × Parts ; 3 × Lines ; 2 × Pin-Joints

Line and Line and Parts are kinematically-defined

Line and Part is not kinematically-defined.

Lines are joined with Pin-Joints to each end of Line

Line has a dimension (in the Part-Editor)

Add Gear-Pair

Simple Gear-Pair

MD-CM-AddGearPair-0

STEP 1: Click Add Gear-Pair (Simple)

1.Mechanism menu > Add Gear-Pair

1.Machine-elements toolbar > Add Gear-Pair

There are four elements to select in the Command-Manager

MD-ADD-GEARPAIR-1

STEP 2: Select the four elements

1.Mechanism-Editor > Click Line

2.Mechanism-Editor > Click Line

3.Mechanism-Editors : Click Line

MD-ADD-GEARPAIR-2

STEP 2: continued...

The Part-Editor opens automatically.

4.Part-Editor: Click the Dimension

The Part-Editor closes automatically.

MD-CM-AddGearPair-full

STEP 3: Complete the Command

5.Command-Manager: Click in the Command-Manager.

Result:

The Gear-Pair is in the graphics-area.

The default Gear-Pair has an External Mesh and they have same number-of-teeth.

The length of the Line between the centers of the gears - called the Line-of-centers - is now a Driven-Dimension.

The length of the Line-of-Centers = (# Gear-Teeth 1 + # Gear-Teeth 2) × Module

The output Part is a Geared-Rocker in the Kinematics-Tree.

To edit the Gear-Pair parameters: see Gear-Pair dialog

MD-ADD-GEARPAIR-3

Epicyclic Gear-Pair

MD-CM-AddGearPair-0

STEP 1: Click Add Gear-Pair (Epicyclic)

1.Mechanism menu > Add Gear-Pair

1.Machine-elements toolbar > Add Gear-Pair

There are four elements to select in the Command-Manager

MD-ADD-GEARPAIR--EPI-1

STEP 2: Select the four elements

2.Mechanism-Editor > Click Line

3.Mechanism-Editor > Click Line

4.Mechanism-Editor > Click Line

MD-ADD-GEARPAIR--EPI-2

STEP 2: continued...

The Part-Editor opens automatically.

4.Part-Editor: Click the Dimension

The Part-Editor closes automatically.

MD-CM-AddGearPair-full

STEP 3: Complete the Command

5.Command-Manager: Click in the Command-Manager.

MD-ADD-GEARPAIR--EPI-3

Result:

The Gear-Pair is in the graphics-area.

The default Gear-Pair has an External Mesh and the gears have same number-of-teeth.

The length of the Line between the Gear centers - called the Line-of-centers - is a Driven-Dimension.

The length of the Line-of-Centers = (# Gear-Teeth 1 + # Gear-Teeth 2) × Module)

The output Part is a Geared-Rocker in the Kinematics-Tree.

To edit the Gear-Pair parameters, see Gear-Pair dialog

Kinematics-Tree of Gear-Pair

Add Gear-Pair removes one degrees-of-freedom.

MD-ADD-GEARPAIR-KINEMATICS-TREE

Kinematics-Tree and a Gear-Pair

Before you do Add Gear-Pair:

•a rotating-Part that is kinematically-defined

•a rotating-Part that is NOT kinematically-defined - it has one degree-of-freedom.

After you do Add Gear-Pair:

•the two rotating-Part are kinematically-defined

•the rotating-Part that had one degree-of-freedom is now a Geared Rocker

Videos of Add Gear-Pair

Simple Gear-Pairs:

Epicyclic Gear-Pairs: