2.2 DC Electric Motor
There are many types of electric motor. It comes in various shape, weight and size depend on its functions. Electric motor is used in almost everything like toys,
robot, CD players, watches, subway trains and many more. The main function of electric motor is similar for every type, which is to convert electrical energy into
mechanical energy. Basically, there are two types of electrical motor that is Direct Current DC electric motor and Alternating Current AC electric motor. DC electric
motor is motor that runs on direct current, which the current flow in the circuit is in one direction only. AC electric motor is a motor that runs on alternating current,
which the direction of current flowing in a circuit is constantly being reversed back
and forth.
The specification of DC motor used in Evergreen is a DC motor with power of 25kW and powered with up to 144V battery. The power of the DC motor can
achieved 60kW at peak power supply. The DC motor can achieved speed up to 4000rpm. The average torque produce is 60Nm and can achieved up to 130Nm.
Average current flow in the motor is 191.4A and can achieved until 380A. The weight of the DC motor is 58kg and has efficiency of 94.8.
Source: UTeM’s PGMC Presentation, 2012
2.3 5-Speeds Manual Transmission
Transmission is a set of gears that function to transmitted energy from power source to a drive mechanism. The transmission will change the speed energy that
gain from the power source in this case, the electric motor and transfer it to torque energy through the drive mechanism. A transmission system is also called gearbox as
it is basically a box that containing a configuration of gears. Another main function of transmission system in automobile is to allow the drive mechanism to shift from
forward into reverse without needed to shut off the engine and to provide neutral position when engine is running and vehicle is in stationary state. The transmission
system containing a range of gears, from low to high gear, to make the used of the engine’s torque more effective as driving conditions change. The larger gear low
gear convert higher engine rpm revolution per minutes into higher torque or
energy at lower at lower drive wheel speed by spinning more slowly than crankshaft while the smaller gear high gear convert lower engine rpm into higher speed and
efficiently by spinning faster than crankcase Basically, there are two types of automobile transmission system, which is
manual and automatic. A manual transmission system is an assembly of shafts, gears, and related parts contained in a metal case or gearbox partially filled with lubricant.
In manual transmission system, gears are selected manually by the driver. The driver will decide whether he want to set low gear or high gear, to reverse or to move
forward. An automatic transmission system is a transmission that can change gear ratios automatically as the vehicle moves. In automatic transmission, the driver only
needs to operate a gear-shift once forward or reverse and do not need to control a clutch. The transmission system will decide when to change the gear ratios by
referring to the rpm of the engine. The transmission system that used in Evergreen is a manual 5-speed
transmission system. This transmission is the actual transmission been used in Proton Saga BLM. The condition of PGMC Proton Green Mobility Challenge competition
stated that every participants need to change the ICE engine of the Proton Saga BLM with a DC electric motor, but they need to used the 5-speed manual transmission that
already in the vehicle. The 5-speed transmission system in Evergreen is a transmission that contains 5 choices of gears gear 1 until gear 5 with additional
reverse gear. The gear ratio for every gear in this transmission system is as stated in Table 2.3.1 below:
Gear 1
2 3
4 5
Ratio 3.333
1.954 1.285
0.926 0.755
Table 2.3.1: The gear ratios of the 5-speed manual transmission Source: UTeM’s PGMC Presentation, 2012
2.4 Adapter plate
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