Gear Ratio & Voltage/Current Calculation for 24V 1500rpm BLDC Motor on a Tricycle

In summary, the conversation discussed using a 24V, 1500rpm bldc motor with a power output of 400W to electrically drive a tricycle. The gear ratio needed to decrease the rpm and increase the torque was calculated using an intermediate shaft with a 22 teeth sprocket and a 44 teeth sprocket. The voltage and current generated by the motor when used as a generator was also mentioned, with factors such as magnetic flux, rotor speed, and load affecting these values. A link was provided for more information on the basics of DC generators and AC alternators. The calculation for the gear ratio was also explained, with an example given.
  • #1
Shravan N Agni
2
0
I have a 24V, 1500rpm bldc motor.The power output will be around 400W. We are using it to electrically drive a tricycle. How can I calculate the gear ratio to decrease the rpm and increase the torque? The transmission system includes an intermediate shaft with 22 teeth sprocket and 44 teeth sprocket. Motor is connected to the 22 teeth sprocket and 44 teeth sprocket is connected to the 26in(dia) wheel with gear cassette.

If the motor is used as generator, how can I know the voltage and current generated by it?
 
Engineering news on Phys.org
  • #2
So far as the gear sizing, I cannot say...I've had no experience with such things.

But to the second question, the voltage that is generated at the terminals of the motor when used as a generator is proportional to the magnetic flux produced by the rotor and the speed at which the rotor rotates. There's also consideration to be given to the number of pole pairs there are. The workings of a DC generator and an AC alternator are basically the same, accept that one uses splits rings while the other uses slip rings. \

The current produced will depend upon the load connected, this value will also affect the other values of the generator (i.e. rotor speed, terminal voltage)

Here's a link that will give you an idea of the basics: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/elemot.html

This is just a high level view and probably not what you're looking for since I didn't give you a "fast and dirty" equation. Others will be able to explain more eloquently than myself.
 
  • #3
The basic calculation goes like this:

26" dia wheel has a circumference of pi*26"=81.7"=6.8'/rev
Say max speed of tricycle is 10 mph=15 ft/sec
15*60/6.8=132 rpm at the wheel
total reduction = 1500/132 = 11.3 to 1 to be divided between intermediate shaft gearing and final gearing

Example:
22 teeth on motor shaft to 44 teeth on intermediate shaft = 2 to 1.
22 teeth on intermediate shaft to 124 teeth on wheel axle = 5.64 to 1.
total reduction = 2*5.64 = 11.3 to 1.
 

1. What is the gear ratio for a 24V 1500rpm BLDC motor on a tricycle?

The gear ratio for a 24V 1500rpm BLDC motor on a tricycle can vary depending on the specific tricycle and motor setup. However, a common gear ratio for this type of setup is around 10:1, meaning that the motor will turn 10 times for every one turn of the tricycle's wheels.

2. How do I calculate the gear ratio for my specific tricycle and motor setup?

To calculate the gear ratio, you will need to know the number of teeth on the motor's gear and the number of teeth on the tricycle's wheel gear. Then, divide the number of teeth on the motor gear by the number of teeth on the wheel gear. For example, if the motor gear has 20 teeth and the wheel gear has 40 teeth, the gear ratio would be 20/40 = 0.5 or 1:2.

3. How does the gear ratio affect the speed and torque of the tricycle?

The gear ratio plays a crucial role in determining the speed and torque of the tricycle. A higher gear ratio, such as 10:1, will provide more torque to the tricycle's wheels, allowing it to climb steep hills and carry heavier loads. However, this will also decrease the speed at which the tricycle can travel. On the other hand, a lower gear ratio, such as 5:1, will provide less torque but allow the tricycle to travel at higher speeds.

4. What is the relationship between voltage and current in a BLDC motor?

In general, as the voltage increases, the current in a BLDC motor will also increase. This is because an increase in voltage leads to a higher electromagnetic force, which requires more current to flow through the motor to generate the necessary torque and rotation. However, the specific relationship between voltage and current can vary depending on the motor design and load.

5. How do I determine the appropriate voltage and current for my 24V 1500rpm BLDC motor on a tricycle?

The appropriate voltage and current for a 24V 1500rpm BLDC motor on a tricycle will depend on various factors such as the motor's specifications, the weight of the tricycle and rider, and the desired speed and torque. It is best to consult the motor's datasheet and consult with an expert to determine the optimal voltage and current for your specific setup.

Similar threads

Increasing the output torque of a DC motor with gears
    • Mechanics
Replies
16
Views
2K
How do I select the right motor and gear ratio for a mid-drive e-Bike?
    • General Engineering
Replies
2
Views
3K
Calculating gear ratio from the motor's graph for an EV?
    • Mechanical Engineering
Replies
3
Views
3K
Chain Conveyor Speed Calculation
    • Mechanical Engineering
Replies
2
Views
8K
Using a DC Motor as a Generator
    • Electrical Engineering
Replies
12
Views
6K
How Do Gear Ratios Affect Stepper Motor Performance in Lock Systems?
    • Introductory Physics Homework Help
Replies
3
Views
1K
Synchronous Machine Voltage Curves & Torque Relation to Armature Current
    • Electrical Engineering
Replies
4
Views
1K
How Can I Design a BLDC Motor with 300W Power, 24V Voltage, and 40 Nm Torque?
    • Electrical Engineering
Replies
3
Views
3K
Troubleshooting a 2 Pole motor running at low speeds on a VFD
    • Mechanical Engineering
Replies
10
Views
3K
Gear Ratios and Constant Power/Torque: find max velocity?
    • Mechanical Engineering
Replies
3
Views
3K

Hot Threads

Recent Insights

Back
Top