Summary of "Care Este Cea Mai Buna Cutie Automata"
Summary of the Video: "Care Este Cea Mai Buna Cutie Automata"
The video is an extensive, detailed technical discussion and review of various types of automotive transmissions, focusing mainly on automatic gearboxes. The presenter explains the mechanics, advantages, drawbacks, and maintenance tips for different transmission types, including Torque Converter Automatics, Dual-Clutch Transmissions (DCT), Automated Manual Transmissions (AMT), Continuously Variable Transmissions (CVT), and electronically controlled CVTs (ECVT). The review also touches on hybrid and plug-in hybrid transmission systems.
Key Points About the Product (Automatic Transmissions):
1. Purpose of Transmission
- Transmissions are necessary because combustion engines have a limited rpm range (idle to ~6,000 rpm), unlike electric motors.
- Transmissions allow the engine to operate efficiently across different speeds and loads.
- Trucks, tractors, and locomotives require many gears due to their engine characteristics and operational needs.
2. Types of Automatic Transmissions Explained
Torque Converter Automatics:
- Most common type.
- Use planetary gear sets and a torque converter (a fluid coupling with turbine, impeller, and stator).
- Torque converter amplifies torque during acceleration.
- Modern torque converters lock up at higher speeds to improve efficiency.
- Controlled by hydraulic valve blocks with solenoids.
- Require regular oil changes (~every 5 years or 60,000 km recommended).
- Sensitive to oil quality and temperature.
- External oil coolers recommended, especially for heavy-duty use.
- Maintenance extends lifespan but eventual rebuild needed after ~250,000-300,000 km.
Dual-Clutch Transmissions (DCT):
- Two Automated Manual Transmissions in one housing.
- Use two clutches (dry or wet) to preselect next gear for faster shifts.
- Dry clutches are electromechanically actuated; wet clutches are hydraulically actuated.
- Wet clutches allow smoother, more powerful engagement but require more complex maintenance.
- Not ideal for towing due to clutch wear; oil should be changed frequently if towing.
- Maintenance intervals similar to torque converter boxes but more sensitive to conditions.
- Complex mechatronics require clean oil to avoid sensor errors.
Automated Manual Transmissions (AMT):
- Essentially manual gearboxes with robotic clutch and gear actuation.
- Cheaper to produce.
- Use hydraulic or electromechanical actuators.
- Require periodic hydraulic fluid and oil changes.
- Maintenance includes relearning clutch engagement points.
Continuously Variable Transmissions (CVT):
- Use variable-diameter pulleys and a belt or chain to provide infinite gear ratios.
- Offer smooth acceleration and efficiency.
- Two main types: push-belt and chain-driven.
- Require careful maintenance; pulleys and belts can wear catastrophically.
- Typically not suited for heavy towing or high dynamic loads.
- Oil changes recommended every 5 years or 60,000 km.
- Some CVTs have a two-speed mechanical gear to improve efficiency.
Electronically Controlled CVT (ECVT):
- Hybrid transmissions combining planetary gear sets and electric motors.
- Used in hybrid vehicles (e.g., Toyota, Lexus).
- Mechanically simpler, fewer wear parts, highly efficient.
- Can simulate multiple gear ratios electronically.
- Combine thermal engine and electric motor inputs for smooth power delivery.
- No clutches or valve blocks, reducing mechanical complexity.
- High efficiency and reliability in hybrid applications.
3. Maintenance Recommendations
- Transmission oil should be changed regularly, ideally every 5 years or 60,000 km, regardless of transmission type.
- More frequent oil changes are advised for heavy-duty use, towing, or city driving.
- Clean oil is crucial to prevent wear and sensor errors.
- External oil coolers can significantly improve transmission longevity.
- Automatic transmissions eventually require mechanical rebuilds, especially clutch packs.
- Dual-Clutch Transmissions are less tolerant of abuse (e.g., towing).
- AMTs require clutch relearning and hydraulic fluid changes.
- CVTs need pulley and belt inspections and timely oil changes to avoid catastrophic failure.
4. User Experience and Practical Insights
- Automatic transmissions provide comfort and ease of use but come with maintenance costs.
- Electric vehicles generally do not require traditional transmissions, but some hybrid and electric vehicles use variations of these systems.
- Some manufacturers charge high prices for electric vehicle maintenance despite simpler mechanics.
- Dual-clutch boxes offer fast and sporty shifts but can be less durable under heavy loads.
- Torque Converter Automatics are robust and prevalent but less efficient than DCTs or CVTs.
- CVTs offer smooth driving but may lack towing capacity and dynamic performance.
- ECVTs provide the best balance of efficiency, simplicity, and hybrid functionality.
5. Comparisons and Examples
The presenter uses examples
Category
Product Review
