Design and calculate shafts

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PROFESSOR: After completing this lesson,

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you'll be able to define a shaft using the Shaft Generator,

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to validate the design of the shaft using loads and supports,

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and be able to apply an involute spline to the shaft using

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standard geometry.

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To access design accelerators, switch to the Design tab.

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In the Design tab, you'll see various categories.

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Under the power transmission panel,

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we'll find the Shaft Generator.

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Starting the Shaft generator, we'll

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get a preview of the last shaft created.

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I'll click on the screen to apply a temporary location

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for the shaft.

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I'd like to change my view style to add some additional clarity.

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I'll turn off the ambient and object shadows.

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Now we can see the correlation between the segments

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of the shaft and the rows in the dialog.

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Selecting a row will highlight the segment in the shaft.

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We can edit any of the segments directly from the dialog

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or by clicking and dragging grips in the design window.

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The tapered section is one that I'd like to remove.

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So I'll select the x and tell it to remove that segment.

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You'll see that the final segment simply

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moves over to match up with the segment above it in the dialog.

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Taking a closer look at the first segment,

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we can see the fillet, the transitions

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into the next segment, and a preview of the chamfer that

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starts the segment.

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These are represented in the end treatments on the row.

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I'd like to remove each of these end treatments,

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changing them to no feature.

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I can either drag the segments on the screen

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or double-click the row to change the diameter

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and length of this segment.

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Clicking OK will update the shaft.

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Now I'd like to add a different end treatment

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to start the shaft out.

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Under the fly-out, I'll select a thread,

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change the length of the thread to 1,

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and leave the rest of the specification as listed.

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This will add a preview of where the threaded segment ends.

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Now I'd like to remove the other end treatments on the next row

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and make modifications to its size,

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setting the diameter and the length.

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Continuing on, quickly make modifications

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to the diameter and the length of each segment

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until I have most of the shaft defined.

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Now I'd like to continue the shaft with two more segments.

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To add a segment or a section, select the Insert Cylinder

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where we can roughen the diameter to be 1

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and change the length.

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A double-click on the arrow will also

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bring up a dialog that will allow us to set the values.

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Now we'll add one more section, setting the diameter

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to 0.75 and the length to 0.55.

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This will give us the physical values

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that I think we're going to need for our shaft,

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but we need to validate whether or not the shaft will work.

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It's going to be under fairly low load.

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But just to make sure, we'll go to the Calculation tab.

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I'll change the radial force value in the dialog

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to a torque load.

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The torque load will be roughly 6 pounds of force.

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And I'll locate it to the center of the gear.

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Then I'll add another torque load, which

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will be the opposite force.

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This will be located roughly where our clutch will

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couple with the shaft.

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Next, we need to relocate where the bearing supports are.

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The bearings will be tight to each side of what will

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eventually be a geared section.

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So we'll relocate the bearings and calculate.

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This will give us the information on the shaft.

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And we can use the graph to compare with the shear forces,

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bending moments, deflection angle,

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and even what the ideal diameters are

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based on these loads.

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As you can see, we're well below any critical value.

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Clicking OK will generate the shaft.

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Inventor will offer us the opportunity

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to change the location or name of the file.

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We'll click OK again.

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Then we can roughly locate the shaft in our assembly.

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Switching back to the Assemble tab,

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we'll use an insert constraint to locate the shaft

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on the bearing.

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Next, I want to go back to the Design tab

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and, Under the Parallel Splines pull-down,

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select Involute Splines.

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When the dialog appears, we'll be

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able to select the reference that we want to use

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and where to place the spline.

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We'll establish the second reference

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to set the location for the length.

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And then we have the option of applying a spline to a hub.

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For this model, there is no hub, so we'll deselect the hub

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from the objects to generate.

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The ANSI B92.1 at 37 and 1/2 degrees is the correct spline

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specification.

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The 1 inch nominal diameter is correct,

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but we want 12 splines.

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And we want to set the length.

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We can drag the length out or enter a length directly

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in the dialog.

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Clicking OK will add the splines to the shaft.

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If we need to make a modification

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to a shaft or any other design accelerator component,

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you simply right-click and select Edit

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Using Design Accelerator.

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I want to add another feature to the second segment.

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Clicking the shaft feature pull-down,

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I'll select Add Through Hole.

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This will give me a display for a hole location where

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I can drag it, both in size and in placement and in angle,

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along the shaft.

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If I double-click on the row, I get a complete dialog

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where I am able to modify the hole diameter

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and establish where it will be located,

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either from the first edge, the second edge,

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or setting it to be centered on the shaft section.

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I'll say, from the first edge, that I

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want it located 2.15 inches from the end and click OK.

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When I update the shaft, it will add the through hole, including

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the chamfer that will accommodate

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the pin that's needed to drive the shaft from the clutch

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assembly.