A small torque going through a CVT
can control a high torque sent to the wheels
The CVT (Continuously Variable Transmission) and the gearbox solve each others problems. The 2Way transmission associate the flexibility of the CVT with the high torque transmitted by gears.
No need to switch gears. Better gas mileage. Better acceleration. Less pollution. Cheaper to build.
- The motor can adapt to driving conditions and use:
The motor'speed of minimum pollution in city driving (low speed and low torque)
The speed of maximum efficiency on the road (higher speed)
The speed of maximum power, to pass another car or climb a hill.
- The 2Way transmission can simulate the feeling of driving an automatic transmission.
- The engine can be kept running at the lower edge of its 'sweet spot'. When the driver accelerates the motor's speed move from the lower edge to the higher edge of the sweet spot. If the driver really steps on the gas the engine can accelerate to its speed of maximum power.
- The car can start like the first gear of a manual transmission. The output of the 2Way transmission can go all the way down to zero speed. The torque sent to the wheel at low speed is more than the wheels can use. There is a possibility to start the car with an engine running at low speed and let its speed increase with the speed of the car.
- The 2Way transmission also makes it possible to simulate the driving of a manual transmission by letting the speed of the motor oscillate between the limits of its sweet spot.
We have been jumping up and down from one ratio of the gearbox to the next for more than a century. An improvement was overdue. After the manual and the automatic transmission the 2WAY Transmission is the "Transmission 3.0,1".
HOW IT WORKS
The name 2WAY means that the power of the motor is divided into two different channels BLUE and GREEN. Each channel includes different elements and different gear ratios before they are put back together.
The 2WAY transmission inserts a CVT between the sun gear Va and the planet gear Vb.
The power from the motor is divided into two channels. One channel goes through the sun gear Va (GREEN). The other channel goes through the CVT and the planet gear Vb (BLUE).
The ring gear Vc of the epicyclic puts back the two channels together. The speed of rotation of the ring gear Vc is a function of Va and the CVT.
This combination of a gearbox with a CVT has all the advantages of a CVT without its problems:
- The output speed Vc varies continuously. No need to switch gears.
- The ratio of the CVT can be limited between 0.50 and 2.
- The output speed Vc can go all the way down to zero speed and deliver a very high starting torque.
- Only half the power goes through the CVT. It can be used in more powerful cars and maybe trucks.
- The 2Way transmission does not transmit a torque to the wheel. It transmits power. At any speed of the vehicle the 2Way transmission can send to the wheels the maximum power that the engine is capable of producing. The 2Way transmission makes it possible to get more power out of a smaller engine.
MANY DIFFERENT IMPLEMENTATIONS ARE POSSIBLE
The are 3 ways to insert a CVT between 2 shafts of the epicyclic
For each one of these possibilities the gear ratio can change the speed range of the output.
The possibility to have a zero output speed solves many technical problems.
The CVT is between the shafts A and B:
V: CVT's ratio
G: Gear ratio between shafts A and B - G<0 if the number of gears is even (change of direction)
V2 = Vc = 2 Vb - Va
Vb = G V Va
Output V2 = Input V1 ( 2 G V - 1)
With a gear ratio G = 0.75
when the CVT ratio V varies from 0.66 to 1.33
the output speed V2 varies from zero to 100% of the input speed V1.
The speed of the motor can be reduced when idling.
The CVT is between the shafts A and C:
V: CVT's ratio
G1: Gear ratio between shafts A and C G1 > 0 if Va and Vc turn in the same direction
G2: gear ratio between Vb and output V2 G2 < 0 if Vb and output V1 turn in opposite directions.
V1 = Va V2 = G2 V Vc = 2 Vb - Va Vc = G1 V Va
Output V2 = Input V1 ( G2 + V G1 G2) /2
Many output speed ranges V2 are possible by changing the gear ratios G1 and G2
G1 and G2 can be <0 or >0
The CVT is between the shafts B and C:
V: CVT's ratio
G: Gear ratio between shafts B and C - G<0 if the number of gears is even (change of direction)
Vc = 2 Vb - Va
Vc = G V Vb
Output V2 = Input V1 ( G V / (2 - G V))
With a gear ratio G = o.8
When the ratio V of the CVT varies continuously from o.5 to 2
The output speed V2 varies continuously from 25% to 400% of the input V1
THE MANY ADVANTAGES OF INSERTING A CVT
BETWEEN 2 SHAFTS OF A GEARBOX
- The motor can be kept running at the speed of your choice – all the time.
Increasing gas intake will increase the torque but the speed of the motor can remain constant.
The motor can adapt to the driving conditions:
Speed of lower pollution in the city (Slow speed)
Speed of maximum efficiency on the freeway (higher speed)
Speed of maximum power to climb a hill (High torque)
When the speed of the vehicle decreases the torque increases. The vehicle can climb very steep hills.
- Dynamic braking can be implemented
Dynamic braking is not reserved to electric cars. The battery can be recharged when the vehicle slows down to the red light and this energy can be used right away to speed up. No need to wait for the lithium batteries.
The only limit is the speed range of the output. There are many ways to satisfy this requirement. As long as the power of the motor is higher than the losses, the vehicle can keep accelerating.
The power available from the motor is not limited by the torque it can deliver at a certain speed. The maximum torque that the motor can ever produce is always available. This is not only true when starting but also true at any speed of the vehicle.
With a 2WAY transmission a small motor can produce a very high torque. There is a possibility to make a better electrical vehicle with a smaller motor.
- The 2WAY transmission also works with a differential:
The epicyclic and the differential have something in common. They both have three gears meshingly engaged and rotating around the same axis. The 2WAY transmission can be used with both of them. Click here for details