Lecture 16 – WORM GEARS WORKED OUT PROBLEMS. Design a worm gear set to deliver 12 kW from a shaft rotating at 1500 rpm to another. 3 / 16 1 Task 1.1 Task To calculate a worm gear with center distance 100 mm. The worm has 2 teeth, and the worm wheel has 41 teeth. Formulas for gear calculation – external gears Contents: Relationship between the involute elements Determination of base tooth thickness from.
Worm Gears • Ball Bearings •. The Type of Strength Calculation is set to Design Key Length if the intent is to have the key. Create a gear box for an. Introduction to Gears A gear is a rotating machine part having cut teeth, which mesh with another toothed part in order to transmit mechanical motion and power. Gears are very versatile machine elements; they range in size and use from tiny gears in watches to large driving gears in punch presses.
Gear
Generator
Animation:
* Shift + Enter: Set RPM of the selected gear
Connection properties
Gear properties
* Shift + Enter: modifies the Diametral pitch
Download
Display
Units
Gear Generator is unitless: if you wish it's inches, cm or millimeters. DXF opened in AutoCAD will have the same value for D/P as it is set above. Gears in SVG are measured in pixels, which is the value multiplied with the scale (Pixel per Unit) as it is displayed on the right side.
About
Gear Generator is a tool for creating involute spur gears and download them in DXF or SVG format. In addition it let you compose full gear layouts with connetcted gears to design multiple gears system with control of the input/output ratio and rotation speed. Gears can be animated with various speed to demonstrate working mechanism.
Why this tool was created? Just for fun. I'm working on a hobby project, a scale construction machine, which needed some spur gears, and I quickly made a simple spur gear creator script in Javascript with SVG output. As it was done, I couldn't stop, and I added more and more features, and finally I got this tool. It was a pleasure to code the whole thing, I'm a bit sad it is already done.
Support: abel@iparigrafika.huNotes about browser compatibility: all new major browsers are supported (i didn't tested IE), but unfortunately Chrome can't render SVG circle correctly. The winners are: Opera for the best performance (shame on me, I never use it) and Firefox for the best looking SVG render.
Update 1.4: TA-DA: Added internal gear support, and the ability of positioning the first gear.
Update 1.3: Fixed DXF file format.
On YouTube
Finally some videos I found on youtube:
Gear Generator How to Draw Perfect Gears (4:23)
Laser Cut Gears (3:08)
Prototype your gear sets in 2D (1:19)
Check out other tools I made:
Print Charts, Flip.World, HTML Spirograph.
Input Parameters
Teeth type - common or spiral
Gear ratio and tooth numbers
Pressure angle (the angle of tool profile) α
Module m (With ANSI - English units, enter tooth pitch p = π m)
Unit addendum ha*
Unit clearance c*
Unit dedendum fillet rf*
Face widths b1, b2
Unit worm gear correction x
Worm size can be specified using the:
- worm diameter factor q
- helix direction γ
- pitch diameter d1
Auxiliary Geometric Calculations |
Calculated parameters
Common gearing ZN
Axial module | mn = m |
Normal module | mx = mn cos γ |
Axial pressure angle | αx = a |
Normal pressure angle | αn = arctg (tg α cos γ) |
Helix/lead angle | γ = arcsin z1/q |
Spiral gearing ZA
Axial module | mn = mx / cos γ |
Normal module | mx = m |
Axial pressure angle | αn = arctg (tg α cos γ) |
Normal pressure angle | αx = α |
Helix/lead angle | γ = arctan z1/q |
Normal tooth pitch
Axial tooth pitch
px = πx |
Basic tooth pitch
Lead
pz = z1 px |
Virtual/alternate number of teeth
Helix angle at basic cylinder
sin γb = sin γ cos αn |
Worm pitch cylinder diameter
Worm gear pitch circle diameter
d2 = z2 mx |
Worm outside cylinder diameter
Worm gear outside circle diameter
da2 = d2 + 2m (ha* + x) |
Worm root cylinder diameter
Worm gear root circle diameter
df2 = d2 - 2m (ha* + c* - x) |
Worm rolling(work) circle diameter
Worm gear rolling(work) circle diameter
dw2 = d2 |
Worm gear root circle diameter
Center distance
Worm Gear Design
Chamfer angle of worm gear rim
Worm tooth thickness in normal plane
Worm Gear Design Calculation
Worm gear tooth thickness in normal plane
Worm tooth thickness in axis plane
sx1 = s1 / cos γ |
Worm Gear Calculation
Worm gear tooth thickness in axis plane
Work face width
Worm Gear Design Guide
bw = min (b1, b2) |
Contact ratio
εγ = εα + εβ
where:
Minimum worm gear tooth correction
where:
ha*0 = ha* + c* - rf* (1 - sin α) | |
c = 0.3 | for α = 20 degrees |
c = 0.2 | for α = 15 degrees |