Best card diagnostic solutions
  • Fast Dispatch And
    Delivery
  • Highest Quality
    Standard & Safety
  • 100% Satisfaction
    Guaranteed
  • Best Value for
    your money
  • Great Customer
    Service

Honda automatic transmission (MRPA) – mechanical

Honda automatic transmission (MRPA) - mechanical 1
admin

Without keyword

The article will focus on Honda’s MRPA automatic gearbox, installed on cars such as the Honda Integra and Acura RSX. This part of the article will focus on the mechanical part of this gearbox..

An automatic transmission consists of a torque converter and three shafts with gears providing five gears for moving forward and reverse gear, as well as hydraulic and electronic control systems.

Torque converter, gears and couplings

The torque converter consists of pump, turbine and reactor wheels assembled in a single unit. The pump wheel is driven by the engine crankshaft. On the outer diameter of the torque converter there is a ring gear, which engages with the starter gear during engine start-up. The torque converter acts as a flywheel when transmitting power from the engine to the gearbox.

The gearbox consists of three parallel shafts: input, intermediate and output.

On the input shaft, located coaxially with the crankshaft of the engine, there are fourth and fifth gear clutches, fourth and fifth gear pinion gears, a spurious gear and a reverse gear.

On the output shaft, the driven gears of all five forward gears, the reverse gear, the gear of the parking gear and the driving gear of the main gear are located. The drive gear of the main transmission is made as a unit with the output shaft. The gears of the fourth gear and reverse gear freely sit on the output shaft and can be rigidly connected to it, depending on the position of the selector, thereby ensuring the inclusion of the fourth gear or reverse gear.

Couplings for engaging first and second gears, as well as gears of first and second gears and a spurious gear, are located on the intermediate shaft.

The shaft of the additional spurious gear is located between the input and intermediate shafts. When you turn on the first or second gears, the power flow goes from the input shaft, through an additional spurious gear, to the intermediate shaft. The gears of the input and intermediate shafts are in constant gearing with the corresponding gears of the output shaft. When the clutch switches on a certain combination of gears (a certain transmission), the power from the engine is transmitted further to the wheels through the input, intermediate and output shafts.

The electronic control system includes a control unit (PCM), sensors and solenoid valves. Electronic control provides the most accurate gear shifting and turning on / off the torque converter lock-up at all speeds and vehicle driving modes.

Hydraulic part of control system

The valve block consists of a main valve block, a regulator block and a servo block. They are attached to the converter housing..

The main valve block includes: a range selection valve, hydraulic valves A, B, C, E, a safety valve, a torque converter lockout control valve, an automatic transmission cooling system valve, a servo control valve and a working fluid pump gear.

The regulator unit includes: a regulator valve, a torque converter control valve, a torque converter lock-on valve, and first and third gear accumulators.

The servo drive unit includes: a servo valve, a hydraulic valve D, hydraulic accumulators of the second, fourth and fifth gears, as well as solenoid valves A, B, C, D and E.

The working fluid from the regulator, through the range selection valve, enters various valves (depending on the included range). The working fluid to the couplings of the first, third and fifth gears comes through the corresponding supply tubes, and to the couplings of the second and fourth gears from the internal hydraulic circuit.

Gear shift mechanism

The transmission control unit, based on signals from sensors and switches, controls the gear shift by sending control signals to the shift solenoid valves A, B, C, D and E and to the pressure control solenoid valves A, B and C.

Shift solenoid valves control the corresponding hydraulic valves that open (close) the lines to the gear clutches.

Pressure control solenoid valves control and maintain fluid pressure to enable proper couplings.

Torque Converter Locking Mechanism

The torque converter lock mechanism works when the selector is in position “D” with second, third, fourth or fifth gears engaged. Along with the hydraulic control of the torque converter, an electronic (control unit) is also provided, which provides the most accurate choice of the moment the lock is turned on (off). The control unit sends a signal to the solenoid valve E, which turns on (or turns off) depending on the signal and controls (turns on or off) a hydraulic lock valve that opens or closes the flow of working fluid to lock the torque converter.

Solenoid valve A controls the operation of the hydraulic check valve blocking the torque converter, which regulates the pressure of the incoming working fluid.

The automatic transmission selector has five positions: P (Park), R (Reverse), N (Neutral), D (Drive) and D3. In the D range, first to fifth gear shifts are possible in automatic mode or in manual gear shift mode (selector in position M). In the D3 range, shifts from first to third gear are allowed.

When you select a range, a certain combination of elements turns on and works..

Range Item Status
P (PARK) The front wheels are locked. The parking pin locks the parking gear gear located on the output shaft. All couplings are off.
R (REVERSE) The reverse gear is engaged. The reverse gear clutch is connected to the output shaft. Fourth gear clutch engaged.
N (NEUTRAL) All couplings are off.
D (DRIVE):
1 – 5 gears
Auto switch The main range for movement. Shifts from first to fifth gear occur automatically depending on the speed of the car and the position of the throttle. Closing the torque converter lock is possible in second, third, fourth and fifth gears.
Manual (sequential) switching Gear changes are made by the driver. Closing the torque converter lock is possible in third, fourth and fifth gears.
D3 (DRIVE): 1 – 3 gears Mode for realizing maximum acceleration. Shifts from first to third gear occur automatically depending on the speed of the car and the position of the throttle. Closing the torque converter lock is possible in second and third gears.

Couplings and gears

In the gearbox, clutches with a hydraulic drive are used to turn the gears on (off). With increasing pressure in the coupling, the piston begins to move, which leads to compression of the friction and steel discs and the cessation of their relative slippage. Thus, the gear through the clutch is connected to the shaft, which ensures the inclusion of the transmission. Similarly, when the pressure in the coupling decreases, the discs diverge, and the gear and shaft are disconnected (transmission is off).

First gear clutch

The first gear clutch is located on the countershaft and enables the first gear to be engaged. The working fluid to the coupling is supplied through the line in the intermediate shaft.

Second gear clutch

The second gear clutch is located on the countershaft and enables the second gear to be engaged. The working fluid is supplied to the coupling via an internal hydraulic circuit.

Third gear clutch

The third gear clutch is located on the countershaft and enables the third gear to be engaged. The clutch is installed in joint with the first gear clutch. The working fluid to the coupling is supplied through the line in the intermediate shaft.

Fourth gear clutch

The fourth gear clutch is located on the input shaft and enables the fourth gear to be engaged. The clutch is installed in the joint with the fifth gear clutch. The working fluid to the coupling is supplied through the line in the input shaft.

Fifth gear clutch

The fifth gear clutch is located on the input shaft and enables the fifth gear to be engaged. The clutch is installed in joint with the fourth gear clutch. The working fluid to the coupling is supplied through the line in the input shaft.

Clutch and gear operation

    Input shaft:
    – The fourth gear drive gear is connected (disconnected) to the input shaft by a fourth gear clutch;
    – The fifth gear drive gear is connected (disconnected) to the input shaft by a fifth gear clutch;
    – The driving gear of the reverse gear is connected (disconnected) with the input shaft by a fourth gear clutch;
    – Spurious gear mounted on the splines of the input shaft and rotates with it constantly.
    Output shaft:
    – The drive gear of the main transmission is made as a single unit with the output shaft;
    – Driven gears of the first, second, third and fifth gears, as well as the gear of the parking mechanism are mounted on the splines of the input shaft and rotate with it constantly;
    – The fourth gear driven gear and the reverse gear are freely rotated on the output shaft. The reverse gear clutch moves and connects the fourth gear or reverse gear to the reverse gear hub. The hub is mounted on the splines of the output shaft, thus enabling the inclusion of a fourth gear or reverse gear.
    Intermediate shaft:
    – The gear wheel of the first gear is connected (disconnected) with the intermediate shaft by a clutch of the first gear;
    – The gear of the second gear is connected (disconnected) with the countershaft by the clutch of the second gear;
    – The gear wheel of the third gear is connected (disconnected) to the countershaft by a clutch of the third gear;
    – Spurious gear mounted on the splines of the intermediate shaft and rotates with it constantly.

An additional spurious gear provides power transmission from the input shaft to the intermediate one. The reverse gear is used to transfer power from the input shaft to the output and change the direction of rotation of the output shaft.

Honda automatic transmission (MRPA) - mechanical 2

Transmission cut. 1 – input shaft, 2 – input gear spurious gear, 3 – fourth gear drive gear, 4 – fourth gear coupling, 5 – fifth gear drive, 6 – fifth gear coupling, 7 – torque converter, 8 – hydraulic lockup clutch-
transformer, 9 – torque converter drive plate, 10 – driving gear of the main gear, 11 – driven gear of the fifth gear, 12 – driven gear of the second gear,
13 – the driven gear of the first gear, 14 – the clutch of the second gear, 15 – the driven gear of the main gear, 16 – the differential, 17 – the intermediate gear of the second gear, 18 – about-
intermediate gear of the first gear, 19 – the clutch of the first gear, 20 – the clutch of the third gear, 21 – the intermediate gear of the third gear, 22 – the spurious gear-
a daily shaft, 23 – an intermediate shaft, 24 – a conducted gear wheel of the third transfer, 25 – a conducted-
May, reverse gear, 26 — fourth gear driven gear, 27 — reverse gear clutch, 28 — parking gear, 29 — output shaft,
30 – the reverse gear shift hub, 31 – the idler gear of the intermediate shaft, 32 – the additional idler gear shaft 33 – the additional idler gear,
34 – the leading gear of the fourth gear, 35 – spurious gear of the input shaft, 36 – about-
reverse gear.

Power flow direction

In this range, all couplings are off. Power is not supplied to the output shaft of the gearbox. Output shaft locked by parking pin.

Power is transmitted from the torque converter to the input gear spurious gear, then to the additional spurious gear and then to the intermediate gear spurious gear. All couplings are turned off and power is not transmitted to the output shaft..

1. The working fluid under pressure is supplied to the first gear clutch and compresses the clutch package. The gear of the first gear through the clutch is connected to the intermediate shaft.

2. The spurious gear through an additional spurious gear drives the spurious gear of the intermediate shaft (intermediate shaft).

3. Power is transmitted from the intermediate shaft to the output through the clutch and gears of the first gear.

4. From the output shaft, power is transmitted through the drive gear of the final drive to the driven gear of the final drive.

Power transfer

Honda automatic transmission (MRPA) - mechanical 3
Honda automatic transmission (MRPA) - mechanical 4

Power Flow Direction (First Gear).
1 – input shaft,
2 – a conducted gear wheel of the first transfer,
3 – spurious gear input shaft,
4 – additional spurious gear,
5 – spurious gear of the output shaft,
6 – clutch first gear,
7 – an intermediate gear wheel of the first transfer,
8 – a conducted gear wheel of the main transfer,
9 – a leading gear wheel of the main transfer.

1. The working fluid under pressure is fed into the clutch of the second gear and compresses the clutch package. The gear of the second gear through the clutch is connected to the intermediate shaft.

2. The spurious gear through an additional spurious gear drives the spurious gear of the intermediate shaft (intermediate shaft).

3. Power is transmitted from the intermediate shaft to the output through the clutch and gears of the second gear.

4. From the output shaft, power is transmitted through the drive gear of the final drive to the driven gear of the final drive.

Power transfer

Honda automatic transmission (MRPA) - mechanical 5
Honda automatic transmission (MRPA) - mechanical 6
Power flow direction (second gear).
1 – second gear driven gear,
2 – spurious gear of the input shaft,
3 – additional spurious gear,
4 – spurious gear of the intermediate shaft,
5 – an intermediate gear wheel of the second transfer,
6 – a conducted gear wheel of the main transfer,
7 – second gear clutch,
8 – a leading gear wheel of the main transfer,
9 – input shaft.

1. The working fluid under pressure is supplied to the third gear clutch and compresses the clutch package. Third gear via clutch connected to countershaft.

2. The spurious gear through an additional spurious gear drives the spurious gear of the intermediate shaft (intermediate shaft).

3. Power transmission from the intermediate shaft to the output is carried out through the clutch and gears of the third gear.

4. From the output shaft, power is transmitted through the drive gear of the final drive to the driven gear of the final drive.

Power transmission

Honda automatic transmission (MRPA) - mechanical 7
Honda automatic transmission (MRPA) - mechanical 8
Power flow direction (third gear).
1 – input shaft,
2 – a conducted gear wheel of the third transfer,
3 – spurious gear input shaft,
4 – additional spurious gear,
5 – spurious gear of the output shaft,
6 – an intermediate gear wheel of the third gear,
7 – clutch third gear,
8 – a conducted gear wheel of the main transfer,
9 – a leading gear wheel of the main transfer.

1. The working fluid under pressure is supplied to the servo valve, which moves the reverse gear clutch. The clutch connects the fourth gear gear with the reverse gear hub. The fourth gear is always connected to the output shaft when the selector is in position “D”, “D3” or “M”.

2. The working fluid under pressure is supplied to the fourth gear clutch and compresses the clutch package. Fourth gear through clutch connects to input shaft.

3. Power is transmitted from the input shaft to the output via the fourth gear clutch and gears.

4. From the output shaft, power is transmitted through the drive gear of the final drive to the driven gear of the final drive.

Power transfer

Honda automatic transmission (MRPA) - mechanical 9
Honda automatic transmission (MRPA) - mechanical 10
Power flow direction (fourth gear).
1 – input shaft,
2 – fourth gear clutch,
3 – a leading gear wheel of the fourth transfer,
4 – a hub of inclusion of transfer of a backing,
5 – fourth gear driven gear,
6 – a conducted gear wheel of the main transfer,
7 – a leading gear wheel of the main transfer.

1. The working fluid under pressure is fed into the fifth gear clutch and compresses the clutch package. The gear of the fifth gear through the clutch is connected to the input shaft.

2. Power is transmitted from the input shaft to the output through the fifth gear clutch and gears.

3. From the output shaft, power is transmitted through the drive gear of the final drive to the driven gear of the final drive.

Power transfer

Honda automatic transmission (MRPA) - mechanical 11
Honda automatic transmission (MRPA) - mechanical 12
Power flow direction (fifth gear).
1 – input shaft,
2 – fifth gear pinion,
3 – fifth gear clutch,
4 – fifth gear driven gear,
5 – a conducted gear wheel of the main transfer,
6 – a leading gear wheel of the main transfer.

1. Pressurized hydraulic fluid is supplied to the servo valve, which moves the reverse gear clutch. A clutch connects the reverse gear to the reverse gear hub. The reverse gear is always connected to the output shaft when the selector is in the “R” position..

2. The working fluid under pressure is supplied to the fourth gear clutch and compresses the clutch package. Fourth gear through clutch connects to input shaft.

3. Power is transmitted from the input shaft to the output via a clutch, a reverse gear, a spurious reverse gear and a driven reverse gear.

4. From the output shaft, power is transmitted through the drive gear of the final drive to the driven gear of the final drive.

RELATED POSTS

  • Honda automatic transmission (MRPA) - mechanical 13

    Honda automatic transmission (MRPA) – electronic control system

    Without keyword We continue the story about the automatic transmission MRPA. The first part of the article talked about the mechanical structure of this…

  • Honda automatic transmission (MRPA) - mechanical 14

    Honda automatic transmission (MRPA) – hydraulic part

    Without keyword Continuing the story of Honda’s MRPA gearbox. In the final part of the article we will tell about the device of the hydraulic part of the…

  • Honda automatic transmission (MRPA) - mechanical 15

    How to slip on automatic transmission? Driving a car – A variety of tips for motorists – Everything for a car in St. Petersburg

    How to slip on automatic transmission? 1. Allow the box to cool in case of a long passage The main sources of heat in the automatic transmission is a…

  • Automatic transmission – Buying a car – A variety of tips for motorists – Everything for a car in St. Petersburg

    Without keyword Follow us on social networks home Tips for motorists Car purchase Now automakers are increasingly installing automatic transmissions on…

About admin

Leave a Reply

Your email address will not be published. Required fields are marked *

© Copyright 2018 Carscanners. All rights reserved.
error

Enjoy this blog? Please spread the word :)