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World-first Compact 7 gears auto transmission for evs

Transmission ‘Should-be-used’ in EV
BYGEN NH7AT
Competitiveness
Design & Connecting
Competitiveness of NH7AT
No Hydraulic 7 Gears Auto Transmission
Transmission effects
Efficiency(km/kWh) increases by over 50%
compared to the same output performances (Refer to Test Data)
Battery usage: “60kWh
40kWh

▶ Significant cost-cut
   • Over 50% efficiency improvement
1/3 smaller battery
       (from 60kWh to 40kWh)
   • No overheat
No need of cooling systems
   • No high frequency noise
No cost for preventing noise
   • 50% Cost reduction of core powertrain (PCU + Motor + Transmission)
Auto Transmission in EV
▶ EV industry has made continuous efforts to reduce production cost by increasing driving efficiency such as increasing energy density,
      decreasing weight of vehicle and increasing motor/inverter efficiency. Nowadays, auto transmission emerges as the most powerful solution
      for increasing driving range for EV
.
▶ Porsche adopted two speed auto transmission for new Taycan. Ford and KYMCO (Chinese Taipei, EV2W) introduced 6-speed manual
      transmission for their vehicles.
      • Compact sized auto transmission to satisfy preconditions for EV has not been developed so far in EV industry.
Multi-speed transmission to provide higher efficiency will be the key for EV competitiveness.
NH7AT will be game changer of EV.
      ※ EU decided stiffer penalties for ICE vehicles from 2021.
New ICE production is not permitted soonest.
In-house PCU Development
PCU(Powertrain Control Unit)
     
MCU(Motor Control Unit) + TCU(Transmission Control Unit)
















▶ Sophisticated and state-of-the-art TCU is developed by in-house technology to make “Zero Shift Time-lag”.
      Independent and core powertrain (PCU+Motor+Transmission) system is constructed.
Competitive Edge of NH7AT
Performance effect
Efficiency (km/kWh) improved by 50% comparing to same spec (refer test report)
Battery capacity from 60kWh to 40kWh
Production cost is radically cut.

Mass production
▶ Total parts are reduced 1/10 than conventional transmission, which is easy to be assembled.
      • Compact design and less parts to delete hydraulic (or other substitutes), clutches (torque converter), satellite gears, ring gear and
      hydraulics-controlled parts. multi-plate clutched, brake, valve bod, etc.

Mounting
▶ Mounted on chassis without current EV platform change
      • Total size combined motor and transmission is smaller and lighter than conventional transmission including reducer.
▶ NH7AT is to be mounted on ICE.
      • Efficiency will increase by over 10%. Production costs and weight will decrease by over 70%.
      • Gear is automatically transferred to neutral when vehicle speed is under constant speed (about 5km/h) at brake “ON” mode.
     
At brake “OFF” mode, it is automatically transferred to first gear.
      • It could be applied to heavy-duty EV2W as well as EV4W
     
Exclusive compact sized auto transmission for heavy-duty EV2W

COST
With Bygen’s innovation, it radically cut production costs as well as efficiency improvement.
▶ Unique and exclusive solution to apparently cut EV Cost.
AS-IS vs. TO-BE
Based on EV4W (as for EV2W, Refer to Test Data)
Items Single Speed EV
(AS-IS)
NH7AT EV
(TO-BE)
Remarks
Efficiency (km/kWh) - Increase by 50% 1/3 battery capacity
(60kWh
40kWh)
Driving System Vehicle speed totally depends on motor speed. Multi gears control torque and rpm while electric motor runs within rated range.
Cooling System Fluid cooling system indispensable No cooling system No over-temperature due to motor operating within rated range.
Motor IPMSM IPMSM IPMSM and BLDC Motor are almost same.
Control System Expensive inverter to use field weakening control PCU(Powertrain Control Unit)
MCU(Motor Control Unit) +
TCU(Transmission Control Unit)
Size of price of PCU decrease by 50%.
Transmission 1st gear reduction by reducer Weight is less than 20kg including reducer and shock absorber. Total size of motor and transmission is smaller than conventional motor including reducer.
Durability Little possibility to early repair parts due to no load on shifting and maintaining gears. see ‘NH7AT Shifting Mechanism'
Vehicle weight Smaller battery, No cooling system. Realization of lightweight
Torque-RPM Narrow torque-rpm combination Wider range of torque-rpm range 4 times stronger output torque than single speed motor
Powertrain Costs
(controller + motor + Transmission)
Expensive inverter and motor Total cost including transmission is lower than single speed EV. • PCU costs 1/3 lower than inverter.
• No cooling system (motor and inverter)
Total cost • Expensive battery cost
• Cooling system cost
• High frequency noise blocking cost
• Expensive powertrain
• Reducing (1/3) battery cost
• No cooling system(motor & controller)
• No high frequency noise
• Reducing (1/2) controller cost
Prominent cost-down for EV