GoldenMotor.com Forum

General Category => Electric/Hybrid Car Conversion => Topic started by: Praveen on June 08, 2012, 07:01:02 AM

Title: Re: Electric passenger Trike technical Information needed
Post by: Praveen on June 08, 2012, 07:01:02 AM

Hi
i have planned to buy a kit of 10kW BLDC motor air cooled kit with 1:12 Gear bridge .
Can u guide me whether my selection is right for the following......

Vehicel speed I needed :Max 55kmph
Vehicle GVW : Max 1500kg
Vehicle Gradient angle : 12degree max

Any idea how much % regen energy can contribute ?


Suggestions and ideas needed......

Title: Re: Electric passenger Trike technical Information needed
Post by: Bikemad on June 09, 2012, 01:57:07 AM

I think you might be asking the impossible from a 10kW motor with that amount of weight and fixed gearing, which would need at least an 18" outer diameter tyre and the 8:1 gear ratio in order to reach 55kmph with the motor running at ~5,100rpm.

Now let's take a look at the following diagram:
(http://www.arhservices.co.uk/GoldenMotor/Hillforces.JPG)

To move a 1,500kg vehicle up a 12 degree slope you would need to exert a force of at least 312kg (1,500 x Sin 12) and that's without allowing for frictional forces at the tyres, mechanical losses through the gear-train and wind resistance etc.

I put some test figures into my spreadsheet (http://goldenmotor.com/SMF/index.php?topic=3024.msg18173#msg18173), and discovered that the motor would need to develop at least 88Nm of torque before the vehicle would even move, let alone accelerate up the slope.

I estimate, the motor draws around 5Amps/Nm @ 120V (http://www.goldenmotor.com/eCar/HPM10KW%20(120V)%20Data.pdf), therefore 88Nm x 5Amps = 440Amps (52.8kW)
I estimate, the motor draws around 8.5Amps/Nm @ 72V (http://www.goldenmotor.com/eCar/HPM10KW%20(72V)%20Data.pdf), therefore 88Nm x 8.5Amps = 748Amps (53.8kW)

Either way, I think 53kW is probably expecting a bit too much from a 10kW motor.

In order to provide a greater gear reduction for hill climbing and a lower gear reduction for speed, I really think you would need to incorporate a manual gearbox so you could easily select the best gear ratio to suit the actual load on the motor.

Alan
 
 

Title: Re: Electric passenger Trike technical Information needed
Post by: Praveen on June 15, 2012, 06:07:47 AM

Hi thanks for the reply 8).

i have noted your details.Has anyone really bought the motor with axle and ground tested practically ?
In such a case can u pls post the pin point datas with photos. ?

Regards
Praveen.