Honda Accord Hybrid teardown (Part 3)

Sport Hybrid i-MMD drive unit

2014/02/28

Summary

The cutaway model of the drive unit of the Honda Accord Hybrid and Plug-in Hybrid
The cutaway model of the drive unit of the Honda Accord Hybrid and Plug-in Hybrid (exhibited at the JSAE Automotive Engineering Exposition held in May 2013)
* Click on the photo for a larger image

 The disassembly of the Honda Accord Hybrid was conducted in January 2014 by the Automotive Technology Innovation Center of the Hiroshima Industrial Promotion Organization. Disassembly of the Power Control Unit (PCU) and chassis components is reported in "Honda Accord Hybrid teardown (part 1)". The disassembly of the lithium-ion battery packs and other components of the Intelligent Power Unit (IPU) and the electric servo brake system are reported in "Honda Accord Hybrid teardown (part 2)". This third and last report highlights the drive unit of the SPORT HYBRID i-MMD (Intelligent Multi-Mode Drive) system.


Related Reports:
Honda Fit Hybrid teardown: Part 1, Part 2 (Dec. 2013)
Toyota Aqua (Prius c) teardown: Part 1, Part 2 (Nov. 2012)
Nissan Leaf teardown: Part 1 (Mar. 2012), Part 2 (Sep. 2012), Part 3 (Nov. 2012)




Configuration of drive unit

Engine : 2.0-liter (1,993cc) in-line 4-cylinder Atkinson-cycle gasoline engine (max. output: 105kW/143ps, max. torque: 165Nm/16.8kgf-m), type: LFA
Drive motor : AC synchronous motor (max. output: 124kW/169ps, max. torque: 307Nm/31.3kgf-m), type: MF8

 

Configuration EV drive mode
Configuration EV drive mode
The e-CVT consists of the drive motor, generator, clutches, etc. The vehicle is driven by the drive motor powered by lithium-ion battery.

 

Hybrid drive mode Engine drive mode
Hybrid drive mode Engine drive mode
The engine drives the generator to generate electricity. The vehicle is driven by the drive motor alone using the generated electricity. The electric power is also used to charge the lithium-ion battery. The clutch connects the engine's output shaft to the wheels directly and the vehicle is driven by the engine. The generator charges the lithium-ion battery. The drive motor assists the engine drive with the generated electric power as needed.

Drawn by MarkLines based on Honda's press releases

 

 



Before disassembly

 

A bottom view of the vehicle front A bottom view of the vehicle rear
A bottom view of the vehicle front exposing the exhaust pipe at the center. The red arrow points to the catalytic converter, the blue arrow to the pre-silencer. The orange-colored pipe by the pre-silencer is made of aluminum and conceals high-voltage cable supplied by Sumitomo Electric Industries. A bottom view of the vehicle rear. A double-wishbone rear suspension is seen at the center and the fuel tank (pointed by the white arrow) supplied by Yachiyo Industry behind it.

 

A top view of the engine room A bottom view of the engine room
A top view of the engine room. The white arrow points to the PCU. The e-CVT consisting of the motor and reduction gear is concealed under the PCU. A bottom view of the engine room with the undercover removed. The drive unit is mounted on the subframe with the e-CVT to the right and the engine to the left.

 

 



Drive unit

 

Drive unit
Drive unit Drive unit
The drive unit viewed from the front-side of the vehicle The drive unit viewed from the right-side of the vehicle
Drive unit Drive unit
The drive unit viewed from the front seats The drive unit viewed from the left-side of the vehicle
The drive unit removed from the engine room resting on an all-aluminum front subframe. The white arrow on the upper-left photo points to a silver-colored cover that conceals the catalytic converter. The red arrow points to the cooled exhaust gas recirculation (EGR) system.
The blue arrows on the upper left and upper right photos point to the electric water pump supplied by Aisin, the green arrow to the electric compressor supplied by Denso.
The yellow arrow on the upper-right photo points to casing that contains the motor of the electric Variable Timing Control (VTC) with an electrified cam sprocket on the intake side.
The purple arrow on the lower-left photo points to the intake manifold supplied by Metts and the throttle body supplied by Keihin. The orange arrow points the electric power steering (EPS) supplied by Showa, the pink arrow to the final drive gear with the differential.

 

 



Engine and associated parts

 

Engine
Engine Engine
The left-side photo shows the engine viewed from the left side of the vehicle after the e-CVT (consisting of the motor, clutch, etc.) was removed from the drive unit. The right-side photo shows the engine viewed from the front passenger's seat (the intake manifold and the air cleaner are already removed). The flywheel with the clutch damper is at the lower left of the photo and has a 295mm diameter and weighs 5.8kg.
Gasoline-fueled vehicles and the single-motor hybrid vehicle (the Fit and Vezel Hybrid) have a starter motor built into the cylinder block. The two-motor Accord Hybrid does not have a starter motor.

 

Intake manifold Throttle body
Intake manifold Throttle body
The Metts' intake manifold and Keihin's throttle body are fitted to the engine as viewed on the left-side photo. The intake manifold measures 360mm in length, 200mm in height and 280mm in depth.
The right-side photo shows a rear view of the intake manifold. The black hose at lower center of the photo is the fuel hose supplied by Yamashita Rubber. The white arrow points to the air-fuel ratio sensor supplied by Denso.

 

VTEC hydraulic control valve (Spool valve) Engine Management System (EMS)
VTEC hydraulic control valve Engine management system
The VTEC hydraulic control valve (spool valve) supplied by Keihin is located to the right of the intake manifold. The Engine Management System (EMS) supplied by Keihin is located at the center of the engine room facing the front passenger's seat. The EMS measures 150mm in length, 210mm in width and 45mm in height and weighs 0.64kg.

 

Cooled EGR system After disassembly
Cooled EGR system After disassembly
The cooled EGR system removed from the vehicle. The white arrow points to the EGR valve supplied by MAHLE, the red arrow to the EGR cooler supplied by Maruyasu Industries. The EGR valve measures 80mm in length and 70mm in width. The EGR cooler measures 180mm in length, 55mm in width and 55mm in depth. The post-combustion exhaust gas is cooled to about 100 degrees centigrade by the cooled EGR system. The engine after disassembly. The white arrow points to the electric water pump (weighing 1.8kg) supplied by Aisin. The red arrow points to the electric compressor (weighing 6.22kg) supplied by Denso. The blue arrow points to the cylinder head cover supplied by MAHLE.

 

 



Motor and associated parts (e-CVT)

 

e-CVT
e-CVT e-CVT
The e-CVT removed from the engine. The foreground of the photo faces the engine. The CVT consists of the drive motor, generator, wet multi-plate clutch and reduction gear. The white arrow points to the final drive gear with the differential. The final drive gear is engaged with the drive shaft at the black part at the center (pointed by the blue arrow) to drive the front wheels. A top view of the e-CVT with the left side of the photo facing the engine. The reduction gear, drive motor and generator are positioned in this order from left to right. The red arrow points to the connector to the generator. The blue arrow points to the connector to the drive motor.

 

Generator
Generator Generator
The left-side photo shows the generator without the side cover. The generator is 175mm in diameter and the stator's coil is 35mm in width. The right-side photo shows an inner view of the side cover. The bottom part is positioned over the e-CVT.
The red arrow on the left-side photo points to the high-voltage cable connector. The four pipes over the stator (pointed by the blue arrows) are the oil pipes for the motor cooling oil. Each pipe has an opening facing down from which oil drips to cool the generator and the drive motor.
The white arrow on the right-side photo points to the angle sensor. The sensor is 130mm in diameter and the sensor element (the black ring-like part) is 15mm in width. The yellow arrow points to the oil pipe connecting to the oil pump.

 

Reduction gear
Reduction gear Reduction gear
The left-side photo shows the reduction gear of the e-CVT with the flywheel case (side cover of the reduction gear) removed. The right-side photo shows an inner view of the flywheel case. The red arrow on the left-side photo points to the final drive gear with the differential. The final drive gear is 210mm in diameter and the ball bearing, supplied by NSK, is 95mm in diameter. The opening for the driveshaft is 35mm in diameter. The blue arrow points to the countershaft, the yellow arrow to the generator shaft. The gear is 75mm in diameter. The white arrow points to the input shaft. The gear is 140mm in diameter and the sun gear is 20mm in diameter. The green arrow points to the parking brake pole.
The wet multi-plate clutch and the overdrive gear are located behind the input shaft (pointed by the white arrow). When the vehicle is driven by the engine, the clutch is connected to the overdrive gear to transfer the engine torque to the driveshaft because there is no transmission. The input shaft and the generator shaft gear are connected to transfer the engine torque to the generator and generate electricity.
The orange arrow on the right-side photo points to the oil pump for cooling the motor. The black part (pointed by the purple arrow) beside the oil pump is the strainer.

 

Oil pump for cooling the e-CVT ATF cooler
Oil pump for cooling the e-CVT ATF cooler
An inner view of the oil pump inside the flywheel case (side cover of the reduction gear removed). The white arrows point to the oil pump drive gears for circulating the e-CVT cooling oil. The Automatic Transmission Fluid (ATF) cooler for the e-CVT cooling oil. The cooler is located in front of the front left wheel. The radiator is supplied by T.Rad.

 

Cutaway model of the e-CVT
Cutaway model of the e-CVT Cutaway model of the e-CVT
The cutaway model of the drive unit of the Honda Accord Hybrid and Plug-in Hybrid which were exhibited at the JSAE Automotive Engineering Exposition held in May 2013. The e-CVT portion of the drive unit is enlarged in both photos.
The red arrow points to the clutch, the blue arrow to the input shaft, and the yellow arrow to the generator shaft. The green arrow (on the left photo) points to the overdrive gear, the purple arrow (on the right photo) to the flywheel with the clutch damper, the white arrow to the drive motor, and the black arrow to the generator.

 

 



Accord Hybrid after Disassembly

 

Accord Hybrid after Disassembly
Accord Hybrid after Disassembly Accord Hybrid after Disassembly
Accord Hybrid after Disassembly Accord Hybrid after Disassembly
The Honda Accord Hybrid after disassembly. The photos show the roof panel (upper right), the front seat floor (lower left), and the rear seat floor (lower right).

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