Chain Drive

) node to model a roller chain sprocket assembly in 2D or 3D. This node determines the interaction of the roller chain sprocket assembly, and automatically generates a set of physics nodes that are necessary to describe its behavior.

The geometry of the roller chain sprocket assembly can be created from the COMSOL These parts include a set of domain and boundary selections used for the automatic generation of physics nodes. It is also possible to create or import your own geometry. However, in this case, you need to manually create the domain and boundary selections required by the node.

	See the Chain Drive and Chain Geometries sections for more details about chain modeling, geometry creation, and selection settings.

Click the button(

) to automatically generate the physics nodes required to model the chain drive. Clicking this button makes the following changes in the Multibody Dynamics interface:

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Creates a number of nodes collected under a node group named This node group is only generated if is set to or

	cdr1 is the default name for the first instance of the Chain Drive node and can be changed if needed.

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Creates a number of nodes collected under a node group named . A subnode is added to all the joints if is set to

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Creates a node group named containing two nodes, two nodes and two nodes. These attachment and joint nodes are only generated if the check box is selected The rigid domains are only created if is set to

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Creates a node group named containing a node. Its selection input includes all bushing domains. This node group is only generated if is set to

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Creates a node group named containing a node to model the contact between the sprockets and the chain links. This node group is only generated if is set to

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Creates a named under . The source and destination selections of this are set automatically. This node is only generated if is set to

	Only click the Create Links and Joints button after setting appropriate values for all parameters in the Chain Drive node. The parameters are described in the following sections.

	If you change one or more parameters of the Chain Drive node after the automatic creation of physics nodes, the settings of the associated physics nodes also require an update. Click the Create Links and Joints button again in order to update the settings of the existing physics nodes. A warning message is added under the Chain Drive node to notify when such an update is required.

	If any selection or related parameters of the Chain Drive node are modified after the automatic creation of physics nodes, all associated physics nodes need to be recreated. Click the Create Links and Joints button again in order to do this. Since all physics nodes are deleted and created again during this operation, the update may take a while. A warning message is added under the Chain Drive node to notify when such an update is required.

Select the domains of all chain links of the roller chain sprocket assembly here. If you use a geometry from the COMSOL , a built-in domain selection named Links is automatically selected. This selection is used to create a node for each link plate. This selection input is only available when is set to or

Select the domains of both sprockets of the roller chain sprocket assembly here. If you use a geometry from the COMSOL , a built-in domain selection named Sprockets is automatically selected. This selection is used to create a node for each of the two sprockets. This selection input is only available when is set to

Select the domains of the bushings of the roller chain sprocket assembly here. Bushings are the components present between the roller plate and the pin plate of a chain link. If you use a geometry from the COMSOL , a built-in domain selection named Bushings is automatically selected. This selection is used to create a node for the bushing domains. This selection input is only available when is set to

For 3D models, select the outer cylindrical surfaces of the pin plates here. If you use a geometry from the COMSOL , a built-in boundary selection named Pin Outer Boundaries is automatically selected.

For 2D models, select the inner boundaries of the pin plates here. If you use a geometry from the COMSOL , a built-in boundary selection named Pin Inner Boundaries is automatically selected.

This selection is used to create an node on the outer boundary of each pin plate. This selection input is always available.

For 3D models, select the inner cylindrical surfaces of the roller plates here. For 2D models, select the inner boundaries of the roller plates. If you use a geometry from the COMSOL , a built-in boundary selection named Roller Inner Boundaries is automatically selected. This selection is at the same geometrical position as that of the Pin Outer Boundaries selection.

This selection is used to create an node on the inner boundaries of each roller plate. This selection input is always available.

A is created for each roller plate and pin plate pair, where the nodes belonging to the pair are set as source and destination of the hinge.

For 3D models, select the outer cylindrical surfaces of the roller plates here. For 2D models, select the outer boundaries of roller plates. This selection is used to model the contact between the chain links and the sprockets. If you use a geometry from the COMSOL , a built-in boundary selection called Roller Outer Boundaries is automatically selected.

Select the outer curved boundaries of the sprockets here. This selection is used to model the contact between the chain links and the sprockets. If you use a geometry from the COMSOL , a built-in boundary selection called Sprocket Outer Boundaries is automatically selected.

When is set to this selection and the roller outer boundary selection are used to create a node between the chain links and the sprocketsIf is set to these selections are used for a penalty based rigid contact formulation.

Select the inner boundaries of sprockets here. This selection is used to mount each sprocket on a shaft. If you use a geometry from the COMSOL , a built-in boundary selection called Sprocket Inner Boundaries is automatically selected.

This selection is used to create an and a node on the inner boundary of each sprocket. It is only available when the check box is selected.

For the automatic creation of physics nodes, the node requires a set of domain and boundary selections. In the list,chose whether the selections are to defined by or .

When is set to , the listcontains all roller chain sprocket assemblies present in the node.You can choose any one of them. The selections in the chosen part are automatically identified and taken as the input to the selections required by the node. Since the selection inputs are automatically set, they are in a non-editable state. However, you can edit them by selecting the check box.

When is set to you have to manually create a set of appropriate domain and boundary selections, and associate each selection with the correct selection input in the node.

Specify the name of chain drive in the field. By default, the name is cdr1 for the first instance created; it can, however, be any string. To easily identify the physics nodes created from a specific node, the string is used as an identifier for all node groups and physics nodes it creates.

Chain links can be rigid or elastic. You can also model the effect of elastic bushings between the rigid link plates. Determine the behavior by selecting a — or .

If is set to , a node is automatically created for each link plate. If is set to , a node is additionally created for the bushing domains between every roller and pin plate.

Select a — or .If is set to a node is automatically created for each sprocket.

If or is set to , the node does not create any specific material model node. For these cases, the default node is used for modeling the elastic bodies.

Select a — or The contact method is used to model the contact condition between the chain links and the sprockets. The contact method is available when is or . If the contact method is selected, specify a (pc) used in the contact condition.

When either the links or the sprockets, or both, are elastic bodies, the contact method is availableWhen the is set to ,a node is created under , and a node with the formulation is created in the physics.

For 3D models, select a — , or . Relative rotation between chain links is only allowed about the sprocket axis.

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is available only when is set to This automatically takes the value of the sprocket axis from the geometry part selected in the input.

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For ,select an edge in the automatically added Sprocket Axis subnode. Any edge in the model can be used to specify the sprocket axis. Select the check box to reverse the direction of the sprocket axis.

For all above methods, the sprocket axis is also used to define the direction vector e0 of each node created by the node.

Select an — or . The selected determines the in all nodes created by the node.

Select a — or . Select an option from the list to determine whether the nodes created by the node should be fully rigid or elastic. When is selected, the input in every node is automatically set to When is selected, a Joint Elasticity subnode is added to the node. The elastic properties given in this node are used in the Joint Elasticity subnode created automatically under every node.

Select the check box to add a subnode with a rotational c to every node.

Select the check box to automatically create an and a node with a source for each sprocket.

Select the check box to announce the and nodes related to the chain link in the list of and in other nodes. The attachments related to the sprockets are always announced to other joints.