Open a gear data file. The Gear dialog box appears. This dialog box is the user interface for a gear design utility. You can create designs of spur and internal ring gears.
To create a new gear design, open a gear (.gr) file. Enter your information. Then click the Save As button and name the file.
Gear File
The name of the file you opened is displayed. Save the file with the same name or use Save As to save the file with a new name.
Gear Type
Select either Internal or External.
Number of Teeth
Indicate the number of teeth on the gear.
Pitch Diameter
This is the pitch circle diameter. Engaged gears have pitch circles that are tangent at a point on their connecting center line. This diameter can have no tolerance.
Tip Diameter
This is the diameter of the circle that defines the tips or top lands of the teeth.
Root Diameter
This is the diameter of the circle that defines the bottoms or root lands of the teeth.
Outer Diameter
This is the outside diameter of an internal ring gear. All tooth elements lie inside this circle. A tolerance on this diameter should always be negative.
Tooth Thickness
The Tooth Thickness is the width of the tooth measured at the Pitch Diameter—at the intersection with the pitch circle.
Pressure Angle
The contact between a driving tooth on one gear and a driven tooth on the other gear occurs along a line called the Pressure Line. The Pressure Angle is the angle between the Pressure Line and a line tangent to the two Pitch Circles at their point of intersection.
The actual tooth contact occurs along a segment called the Line of Action. Contact pressure starts when the tip of the driven tooth first touches the flank of the driving tooth. Contact pressure stops just after the tip of the driving tooth first touches the flank of the driven tooth.
Base Fillet Radius
This is the radius of the fillet at the base of the tooth.
Top Fillet Radius
This is the radius of the fillet between the top and the flank of the tooth. It must be less than half the top width.
Backlash
Backlash is the amount by which a tooth space exceeds the Tooth Thickness of the engaging gear at the pitch diameter.
Make the Whole Gear
The SCPRT file will have the entire gear instead of a single tooth.
Provide gear measurement information
This box must be checked if you want to input information in the following boxes.
Type of Measurement
Pin / Ball Measurement
Input the pin diameter. SURFCAM will calculate the diameter to the outer tangency of the pins for external gears. SURFCAM will calculate the diameter between the internal tangency of the pins for internal gears.
Chordal Measurement
You must input the number of teeth to be included in the chordal measurement. SURFCAM will calculate the distance as measured by calipering across the specified number of teeth.