Roller Chains Generator

Use the selection control to browse for appropriate chain within chain library. The chain selection is based on a chain standard (category) and chain type (size of the chain based on pitch).

Use the upper part of the panel to select family (standard) of the chain. The selection effects the lower part of the browse window which displays a full list of available chain sizes or solutions for given family. List of the chain families depends on XML data files stored in ...\Design Data\Design Accelerator\Tables\Chains\RollerChains.

You can customize list of chains as well as add your own chains according to specific chain supplier.

When you finish the chain selection, and the chain corresponds to the input criteria, the Accept current selection command becomes active. Click the command to select the chain and insert it on the Design tab.

Browse for a chain by size

The content of the bottom list contains all chain sizes of selected chain family. The list contains major dimensional properties of the chain such as chain pitch, or width. Depending on your chain selection the diameters of the sprockets are changed. The number of sprocket teeth is fixed.

Click the row to select the chain size.

Browse for a solution with closest sprocket diameters

The content of the bottom list contains possible solutions of the chain drives that use specific chain size and retain the closest sprocket diameters. Number of sprocket teeth might change accordingly. Generator browses for a chain by size and computes strength properties. It preliminary selects what chains might or might not work for such drive. Use this method if bounding box of chain drive is of a major importance. The static and dynamic safety factors are calculated as well as chain bearing area pressure, overall chain weight, design power and chain power rating for smallest number of teeth in the drive.

Preview

Displays a chain preview with appropriate chain dimensions.

Select Chain Mid Plane

Select the chain mid plane. You must select a chain midplane to compute initial drive layout and displays dynamic preview of the chain drive. You can select work plane or any planar face within the assembly. You can also use the active coordinate system icon to adjust the X or Y axis direction and the coordinate origin point.

Number of Chain Strands

Selects required number of chain strands for the design. Valid strands are determined by selected type of the chain. By changing strand property, you change the chain directly (as simplex, duplex, triples and so on). This value has an impact on the whole chain drive. Sprockets update accordingly and adopt number of chain strands. Use the list to select valid number of strands defined for given chain.

Add, remove, or reorder sprockets as well as set main properties of each sprocket. Each sprocket is represented as 1 line of controls within the list. To reorder the pulleys in the list, drag the lines.

Component Inserts a sprocket as a component. Use this option to create a new part document of the sprocket. The application uses predefined template files for sprocket. You can add additional features into sprocket documents. The file name can be selected within the Properties dialog box.

Virtual Does not insert a sprocket into the assembly. This option is similar to the Component option. But no component is created within the assembly. Use this option if it is not clear which sprocket component is used in the assembly. No BOM information is created within the assembly.

Each sprocket within the chain drive has a special rule to identify the position of the center:

Fixed position by selected geometry Selection of Work Point, Work Axis, Cylindrical Face, or Sketch Point is required as a geometrical condition of the sprocket center. You cannot specify coordinates by precise numbers. The position is controlled automatically by projecting a center point into the chain main plane.

Direction driven sliding position Similar to the free sliding position placement. The direction of a specific vector is controlled by selected geometry. Select the Work Axis, Work Plane or Planar Face that needs to be perpendicular to chain plane. You can adjust the specific point only by drag and drop. The generator automatically selects the closest chain length and calculates the exact position of the center to accomplish the chain length condition. The translation plane needs to be perpendicular to the chain main plane. You cannot specify coordinates by exact values or expressions.

Each of the sprockets is editable:

Delete Deletes the sprocket.

Displays additional options for chain drive design. To display the More Options area, click More in the right lower corner of the Calculation tab.

Chain Options

Select the options for spring calculation.

Even Only

Generator determines the closest number of links, round it to even number, and moves the sliding sprocket into the necessary position. You cannot enter the chain links manually.

Custom

Enter the required number of chain links. The generator determines the required position of the sliding sprocket.

Sketch

Creates chain as a simple sketch.

Adjust Timing

By default the sprocket timing is switched off. This means that sprocket timing is computed automatically based on a driving sprocket position.

If you need to adjust sprockets timing, first you need to choose a sprocket with fixed timing constraint. Then, select timing reference geometry (linear entity parallel with main chain plane or planar entity perpendicular to main chain plane). All other sprocket within the chain drive automatically adjusts its rotation to engage with the chain.

Use the graphical preview to view the sprocket timing.

To display the Results area on the right side of the Design and Calculation tabs, double-click the double line on the right or click the chevron.

• Chain
  • Pitch (p)
  • Maximum Roller Diameter (d₁)
  • Maximum Pin Body Diameter (d₂)
  • Transverse Pitch (p_t)
  • Minimum width between inner plates (b₁)
  • Maximum inner plate depth (h₂)
  • Maximum outer or intermediate plate depth (h₃)
  • Maximum width over bearing pins (b)
  • Maximum inner plate width (t₁)
  • Maximum outer or intermediate plate width (t₂)
• Sprocket
  • Number of Teeth (z)
  • Number of Teeth in Contact (z_c)
  • Pitch (p)
  • Pitch Diameter (D_p)
  • Transmission ration (i)
  • Arc of Contact (b)
  • X Coordinate (x)
  • Y Coordinate (y)
  • Center Distance (C)
  • Span Length (L_f)

Displays the reports about calculation. To open the Summary of Messages area at the bottom of the Calculation and Design tabs, double-click the double line at the bottom of tabs or click the chevron at the bottom of the tabs.

A graphics preview of the chain drive gives the visual feedback of the designed chain drive and it also helps with the design because you can adjust the chain drive properties using grips.

Use the drop-down menu to select which properties of a driving machine are known.

Power, TorqueSpeed

Calculates the speed according to the power and torque.

Efficiency

Specify expected efficiency of the chain drive. The usual efficiency is 0.98 [-].

Maximum chain elongation

Specify maximum allowable chain elongation. The elongation is given in percent of the chain length. The value "0.02 ul" means elongation of “2%†of the chain length.

Environment

Specify environmental conditions for a chain drive.

Soiled

Abrasive dust might occur in the environment (outdoor application).

Recommended

The generator recommends an appropriate lubrication method based on the rules (rules based on a chain size and speed). You can see the recommended lubrication within the Summary of messages group box.

Sets mechanical properties of the selected chain because the same size and type of the chain might differ across manufacturers.

Check the box to insert the appropriate value.

Specific mass

Specific mass of the chain depends on the chain size, construction, and material. The default value is taken from standard recommendations or the closest value of steel chains produced by chain manufacturers. The specific mass is used for computing centrifugal force and for vibration analysis.

Chain construction factor

Describes the actual quality of the chain. It directly affects the default chain power rating and chain permissible bearing area pressure. If the factor value is 1, it does not affect standard size both of these properties. Consider modifying this factor if your chain is made from material with better strength or the quality of the chain is actually better than mentioned in national standards.

A list of customized parameters that affect working conditions and tells the generator how much the current operating conditions differ from normal. You can modify any power correction factor. Editing requires a good knowledge of chain drive design, see Engineer's Handbook for more details on power correction factors.

Check the box to display an appropriate dialog box to edit the factor values.

Check the box to enable the strength check within roller and bush area of the chain. If you clear the check box, the stress within chain bearing area is not part of strength check. However, the actual stress is still calculated based on working conditions. If the option is selected, the allowable stress is determined and compared with actual stress calculated based on working conditions. If the comparison fails, the entire strength check fails. See Engineer's Handbook for more details.

Specific friction factor

Specific friction factor corrects permissible pressure in chain bearing area. The size of the correction depends on how much the actual operating conditions differ from normal.

Controls the critical speed of the driver sprocket with respect to natural frequencies of the chain spans. For certain speed and drive setting, vibrations can appear within the chain drive. Such vibrations can result in significant reduction of chain drive service life.

Check the boxes before Chain stiffness and Limit of critical speed to enter their values manually.

See Engineer's Handbook for more information about vibration analysis.

Limit of critical speed

If the chain speed is close to the critical resonance speed, it can result in unexpected additional load in chain drive what can significantly reduce chain drive service live. The error message is displayed if the actual driven sprocket speed is in critical interval.

Displays additional options for chain drive design. To display the More Options area, click More in the right lower corner of the Calculation Tab.

Static

Minimum value of static factor of safety determined for constant load. If the actual value of static factor is smaller than this minimum value, the strength check fails. See engineering handbook for more details.

Lubrication factor impacts just power rating limited by galling between pins and bushings

This option affects the determination of the design power and chain power rating. This option can be considered if the lubrication is not sufficient for given operating conditions and therefore the lubrication factor differs from 1.0. If the option is switched on, the lubrication factor impacts the chain power rating limited by galling between pins and bushings. If the option is switched off, the lubrication factor affects directly design power. See the Engineering Handbook for more details.

Displays the reports about calculation. To open the Summary of Messages area at the bottom of the Calculation and Design tabs, double-click the double line at the bottom of tabs or click the chevron at the bottom of the tabs.