Toyota Camry Hybrid AHV40 Manual page 4

TH-4
3. Clutch-Less System
A clutch-less system is used to mechanically link the front wheels and MG2 via gears. To disengage the
motive force in the neutral position, the shift position sensor outputs an N position signal to turn OFF all the
power transistors in the inverter (which controls MG1 and MG2). As a result, the operation of MG1 and MG2
shuts down, thus rendering the motive force at the wheels to zero.
4. Hybrid Transaxle
D This system drives the vehicle by combining the motive forces of the engine and the MG2 in an optimal
manner in accordance with the driving conditions of the vehicle. In this system, the engine power forms
the basis. The power split planetary gear unit in the hybrid transaxle splits the engine power two ways:
one to drive the wheels, and the other to drive MG1, so that it can function as a generator.
D This hybrid transaxle consists primarily of MG1, MG2, a compound gear unit (which consists of a motor
speed reduction planetary gear unit and a power split planetary gear unit), a counter gear unit, and a
differential gear unit.
D The engine, MG1 and MG2 are mechanically joined via the compound gear unit.
D The compound gear unit contains a motor speed reduction planetary gear unit and a power split planetary
gear unit. The motor speed reduction planetary gear unit reduces the rotational speed of MG2, and the
power split planetary gear unit splits the motive force of the engine two ways: one to drive the wheels, and
the other to drive MG1, so that it can function as a generator.
D In the motor speed reduction planetary gear unit, the sun gear is coupled to the output shaft of MG2, and
the carrier is fixed. Furthermore, the compound gear unit uses a compound gear, in which two planetary
ring gears, a counter drive gear, and a parking gear are integrated.
For details, refer to P311 Hybrid Transaxle on page CH-2.
" A
Image Diagram
Ring Gear
Pinion Gear
MG2
Sun Gear
Compound Gear
Sun Gear
(MG2)
Motor Speed Reduction
Planetary Gear Unit
THS II (TOYOTA HYBRID SYSTEM II)
Compound Gear Unit
Counter
Gear
Ring Gear
Unit
Differential
Gear Unit
Carrier
(Fixed)
Parking Gear
Ring Gear
MG1
Engine
Sun Gear
Pinion Gear
Counter
Drive
Sun Gear
Ring Gear
Gear
(MG1)
Carrier
(Engine)
Power Split Planetary
Gear Unit
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