Calculating Spur Gear Transmissions - Step-by-Step Guide

In summary, the conversation discusses the need to calculate spur gear transmissions and the first steps involved. The data provided includes the speed and torque values, as well as the transmission ratio and load. The individual is unsure of how to select the appropriate material for the gears and is also unsure of how to calculate the module. Resources for material selection and a suggested minimum tooth count for the pinion and bull gear are also mentioned.
  • #1
maths85
6
1
Hello.

I need to calculate spur gear transmissions.
I need a bit of guidance for the first steps.
The data is the next:
n= 1000 rev/min
Mt torque= 28.65 Nm
i transmission ratio= 4
P load in the shaft= 3kW

upload_2016-11-24_17-25-29.png


I am a bit lost to star selecting the material (depending the load and work conditions).
The strees of the transmissions and the module of the gears.

I understand that I need to check the material in a catalogue of materials. But honestly I am lost trying to select the right one and fail at the beginning of my calculation of gears.Later on when I have to calculate the module, which date should I set as I random number, the number of teeth then I will be able to calculate the module later.

Thank you.
 
Engineering news on Phys.org
  • #3
Baluncore said:
www.roymech.co.uk/Useful_Tables/Drive/Gears.html
http://rkgit.edu.in/study_material/me/DesignofSpurGears.pdf
Thank you Baluncore. Do you know where could I find information of the material selection process ?
 
  • #4
Material selection will be decided by things like corrosion, lubrication and loads. You must be able to economically cut, finish, and then if possible, harden a gear.
The gears, shafts, bearings and enclosure must be compatible materials that will not encourage electrochemical corrosion.

Start your calculations with a minimum of 19 teeth on the pinion and 75 on the bull gear which gives a ratio of 3.947. Those tooth counts have no common factors and so will give a “hunting tooth” that wears evenly since every tooth on the pinion will meet every tooth on the bull gear.
20 : 81 = 4.05 is also possible since 20=2*2*5 and 81=3*3*3*3 have no common factors.
 

1. How do I determine the number of teeth on a spur gear?

To determine the number of teeth on a spur gear, you will need to know the pitch diameter and the diametral pitch. The formula for calculating the number of teeth is N = PD x DP, where N is the number of teeth, PD is the pitch diameter, and DP is the diametral pitch.

2. What is the pressure angle and how does it affect gear calculations?

The pressure angle is the angle between the line of action and the tangent to the pitch circle of a gear. It affects gear calculations by determining the shape and strength of the gear teeth. A higher pressure angle results in stronger and more durable gear teeth, while a lower pressure angle can result in smoother operation.

3. How do I calculate the center distance between two gears?

The center distance between two gears can be calculated using the formula CD = (N1 + N2)/2 x DP, where CD is the center distance, N1 and N2 are the number of teeth on each gear, and DP is the diametral pitch.

4. Can I use the same gear ratio for different sizes of gears?

Yes, the gear ratio remains the same regardless of the size of the gears. As long as the number of teeth and the diametral pitch are the same, the gear ratio will be the same. However, the size of the gears can affect other factors such as the center distance and the overall size of the gear system.

5. How do I determine the module of a gear?

The module of a gear is the ratio of the pitch diameter to the number of teeth. It is typically measured in millimeters. To determine the module, you can use the formula M = PD/N, where M is the module, PD is the pitch diameter, and N is the number of teeth.

Similar threads

How can I design a gear train to meet specific torque and RPM requirements?
    • Mechanical Engineering
Replies
2
Views
1K
Calculate the gear ratio for every gear
    • Mechanical Engineering
Replies
4
Views
2K
Tabular Method for a Unique Spur Gear Differential System
    • Mechanical Engineering
Replies
2
Views
2K
Design of Spur Gears for a Gearbox
    • Mechanical Engineering
Replies
9
Views
2K
Gear Wear Rig Design: Calculating Load for Maximum Durability
    • Mechanical Engineering
Replies
6
Views
1K
A gear train design problem
    • Mechanical Engineering
Replies
4
Views
3K
Calculate Gear Ratio - Helical/Spur Gears
    • Mechanical Engineering
Replies
2
Views
2K
Rack and Pinion motor selection
    • Engineering and Comp Sci Homework Help
Replies
3
Views
1K
Planetary gearbox speed calculation - Simultaneous equations
    • Mechanical Engineering
Replies
1
Views
4K
Calc Gear Ratio: Helical/Spur Gears
    • Mechanical Engineering
Replies
7
Views
2K

Hot Threads

Recent Insights

Back
Top