Fuel economy improvement system applied to an auxiliary driving wheels of electric vehicle
This project is on the disconnect equipment applied to EVs for 4WDs, which contributes to improving fuel economy of the vehicle by cutting off the power of the auxiliary drive wheel during 2WD operation, reducing drag torque due to the reverse drive from the tire. This system disconnects the motor power of the auxiliary drive wheel when driving in 2WD, the vehicle drives with the driving force of the main drive motor. At this time, the reverse drive force from the auxiliary drive wheel causes the internal gear/bearing/motor of the drive train to rotate, and It causes loss of power and adversely affects the product’s durability as well. Each drive system is configured on the front and rear wheels in the 4WD vehicle, This system is located on the output side of the auxiliary drive wheel (front wheels), and operates 2WD↔4WD transfer in accordance with the vehicle driving conditions. Interacting with Vehicle Control (VCU) / Motor Control (MCU) according to the driving conditions of the vehicle, and it transfers power from the auxiliary drive motor or cut off reverse drive force from the tire as necessary. The development goals of the system are as follows. ① Improving vehicle fuel economy ② Optimal control system for driving conditions ③ Securing the response performance of engaging/disengaging ④ Securing the Shifting quality ⑤ Securing the Durability / Improving vehicle fuel Economy
1) Disconnectors for Ev’s Reducer Positioned on the output side of the auxiliary drive wheel on a 4WD vehicle consisting of the drive system (motor and reducer) of each front and rear wheels. 2) Optimal design of system It attempt to engage the shaft and sleeve of the dog clutch feature at Δrpm (input & output) of a certain level. As a result, input by the motor inertia & Δrpm is transferred to the dog clutch at the time of engagement, so it is required to ensure durability of the system and minimize impact. 3) Control flow The VCU determines and sends signals to the MCU (rpm change of the traction motor) and the BLDC motor (disconnector operation). When the rpm of the drive motor reaches the wheel rotation speed, the disconnector motor torque is generated and the system is engaged. 4) Design for Shifting quality and durability ① Optimal control (Current control considering shock and responsiveness) ② Dog clutch shape (Securing of abrasion resistance, Setting up backlash)
Next generation thermal systems for electrified powertrains
- Stator and rotor oil cooled electric machines
- Direct cooling and dual phase cooling for power dense inverters
- Immersion and dual phase cooling for battery pack
As BEV and electrified powertrains are gaining steam globally, the engineering community is focusing on key improvements related to these electrified propulsion systems. On top of the efficiency improvement aspect, the increase of power and torque density are key aspects of the current developments. With the increase of power and torque density, the cooling and thermal management becomes a challenge, with increasing power to dissipate for a given surface. This is leading to the development of new approaches and Technologies. Cooling is also a challenge for battery packs, with high charging power technologies being pushed by OEMs to reduce the charging time and increase customer EV acceptance. Ricardo has conducted internal projects on the different parts of the propulsion systems and would like to present the result of these projects, with new solutions for electric machines, inverters and battery, to be used in the next 5 to 8 years.
Design, simulation approach and results for: – Stator and rotor oil cooled electric machines – Direct cooling on GaN chips using di-electric fluid/oil. Addition of indirect cooling on the back plate for power dissipation of up to 300W/m2 – GaN Inverter Dual-phase cooling using di-electric fluid – Single phase battery pack immersion cooling with di-electric fluid/oil – Battery pack Dual-phase cooling using a boiling approach with di-electric fluid.
嘉实多 (上海) 管理有限公司
戈尔公司 是一家全球性材料科技公司，致力于服务工业生产和改善生活质量。自1958年以来，戈尔公司攻克了高要求环境下的复杂技术挑战 — 从外太空到世界最高峰，再到人体内部机制。凭借10,500多名员工和一个强大的面向团队协作的文化，戈尔公司每年营造370亿美元的收入。
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