9.1. General information
|
|
More detailed information on a design, the principles of functioning and service of a design of AW can be found in the Management 179 ("Automatic transmissions of modern cars") ARUS publishing houses. |
Design of typical AT (1 of 2)
Design of typical AT (2 of 2)
For a complete set of the cars considered in the present manual the automatic transmissions (AT) of a series 03-72LE of production of the Aisin Warner company (AW372LE) can be used 4-staged (including the raising transfer).
Playing a role of ordinary coupling at the time of start-off of the car from the place, during the movement AT performs work on gear shifting.
The AT main components are the blocked hydrotransformer (the rotation converter), a three-row step planetary reducer and an electronic and hydraulic control system. Hydrodriving multidisk brakes (4 pieces), obgonny couplings (3 pieces) and multidisk friction clutches (3 pieces) are applied to gear shifting without rupture of a stream of power in a planetary reducer.
Management of switching of all transfers, and also blocking of the hydrotransformer carries out the special electronic module (TCM) working in close connection with the module of engine management (ECM) and continuously communicating with the last.
The possibility of the blocking of the hydrotransformer at the movement in the cruiser mode about speed exceeding some threshold value allows to increase significantly profitability of fuel consumption due to decrease in working turns of the engine.
The liquid cooler of ATF is built in a radiator of the cooling system of the engine, one more, external air cooler is established just before a cooling system radiator.
TCM controls functioning of all AT executive mechanisms (valvate assembly, couplings, brake assemblies) taking into account the choice of one of three set transmission modes: ECONO (the normal mode), POWER or HOLD, - see the Head Governing bodies and methods of operation). On the basis of the analysis of the data arriving from various information sensors (not necessarily directly related to functioning actually of transmission), TCM chooses optimum from the point of view of profitability, smoothness of switchings and so forth the mode of functioning of AT. A component of a control system of AT is the self-diagnostics subsystem, - at detection of serious malfunction the module of management switches transmission to the special emergency (safe) operation with a limited range of switchings. Switching in emergency operation allows to drive away the car under the own steam on car repair shop for performance of detailed diagnostics and necessary recovery repair. On the basis of the data arriving from the mode kickdown, TCM which is traditionally set under the accelerator pedal of the sensor switch of activation carries out switching of transmission on adjacent the pedal which is used at the moment transfer at full squeezing that allows to raise significantly dynamic characteristics of the car, for example during overtaking commission. Thanks to use of the special N/P sensor switch start of the engine can be carried out only when the lever of the AT selector is in situation "P" or "N" that allows to prevent casual start-off of the car in start attempt.
The only procedure of service of AT which implementation has to be made on a regular basis is check of level of working liquid (ATF) which order of performance is stated in the Head the Current leaving and service. Need for regular replacement of ATF is absent.
In the present chapter only the most general procedures of service of AT lying within qualification of the average amateur mechanic are considered. Information on a design and the principles of functioning of the AT separate executive elements is given below.
Valvate assembly
Valvate assembly is located in the pallet of a case of transmission and under control of TCM exercises control of ATF streams in a box. The valves controlling liquid pressure which are a part of assembly are connected among themselves by internal channels. Purification of the transmission liquid (ATF) which is taken away from the pallet of a case is provided with the mesh filter which is built in in a maslozabornik of pump assembly.
Design of valvate assembly of AT
Hydroaccumulators
The main function of the accumulator is ensuring absence of stress of switchings of transmission towards increase in transfer due to smoothing of operation of friction clutches. In the considered transmission three relatives on an accumulator design are used: friction clutches of forward transfers and direct perception and a disk brake of transfers from the 2nd above.
The accumulator consists of the valve and a spring. The main pressure whose action is plused to the effort developed by a spring is constantly attached to the sprung party of the valve and presses the valve when assembly is in an inactive state.
Accumulator design
|
|
|
|
1 — the Working party |
3 — the Main pressure (from the valve of manual switching) |
When giving of the operating pressure upon the corresponding executive mechanism (a friction clutch or a multidisk brake) the same pressure (from the valve of manual switching) is put to the working party of the valve of the corresponding accumulator. Under the influence of this pressure the valve begins to be wrung out down, overcoming the counter-pressure and effort developed by a spring. On filling of working volume the accumulator needs some time by the time of which end the executive mechanism is completely included, - this delay also provides smoothness of operation of an under control friction clutch / brake and, respectively, absence of stress of switching of AT.
Blocking of the hydrotransformer
The blocking coupling provides a possibility of torque transmission from a bent shaft of the engine to directly entrance shaft of O/D of transmission.
Operation of blocking happens only in the cruiser mode at the movement to the speed over 69 km/h (43 miles/h) and at a temperature of cooling liquid not less than 50 °C. At delay of speed of the movement is lower than a threshold of inclusion by raising (O/D) of transfer (69 km/h), as well as at decrease in temperature of cooling liquid 50 °C are below, the blocking coupling automatically is switched-off.
Blocking inclusion
At delivery by the module of management (TCM) of the corresponding team during the movement of the car on the 2nd, 3rd or 4th (O/D) transfer operation of the electromagnetic valve of the blocking coupling leads to opening of drainage channels and, as a result, dumping of the main pressure from the spring party of the operating spool-type valve of the hydrotransformer. Under the influence of the main pressure (from the valve of switching 1-2) brought from the opposite side of a zolotnik there is its switching to supply of the transmission liquid which is under pressure of the hydrotransformer via the turbine on the back party of the blocking coupling, - forced out from the opposite side of the ATF coupling via the operating valve is removed in the case pallet (the stream of the transmission liquid banished through ATF cooler at the included blocking of the hydrotransformer is reduced). As a result the blocking coupling nestles on a forward cover, mechanically with it being blocked. As the coupling has shlitsevy landing on the turbine, from this point a forward cover, the coupling and the turbine begin to rotate as a unit, providing torque transmission from a bent shaft of the engine directly on an entrance shaft of O/D of transmission.
|
|
Equipment of the coupling damping springs allows to reduce the level of the noise and vibrations made by the transmission line. |
Principle of inclusion of blocking of the hydrotransformer
Blocking shutdown
At delivery closing of the electromagnetic valve under the influence of the effort developed by its spring happens the module of management (TCM) of command for shutdown of blocking. As a result of an overshoot of drainage channels and alignment of pressure on both sides of operating hydrotransformer valve, the last under the influence of the effort developed by a spring switches, providing giving of the blocking coupling which is under pressure of the ATF hydrotransformer on the forward party. As a result the blocking coupling is wrung out from a forward cover, bringing the last out of gearing with the block the coupling turbine, - surplus of volume of the liquid which is under pressure of the hydrotransformer is removed via the operating valve in a cooler of ATF and further in the case pallet.
Principle of shutdown of blocking of the hydrotransformer
ATF cooler
At the switched-off blocking of the hydrotransformer transmission generates a large amount of heat which main part accumulates transmission liquid.
For selection of heat from ATF the special two-level cooling path is organized. The first step of cooling is organized by means of laying of tubes of a transmission contour in the lower tank of a radiator of the cooling system. After return of a part of heat of cooling liquid of the engine in a radiator of the cooling system, ATF goes to the oil cooler. The heat exchanger of a cooler of ATF is installed ahead of a radiator of the cooling system and is blown by the running stream of air which selects the remained excess heat at ATF. Pressure of ATF is supported at the constant level of 1.9 atm due to inclusion in a cooling path of transmission of the special perepuskny valve.
The main source of a thermal emission in AT is the hydrotransformer. As at inclusion of blocking of the hydrotransformer turbulence of a stream of ATF in it decreases, also transmission thermal emission power is considerably reduced. Taking into account this factor, in a design of AT function of reduction of a stream of transmission liquid through ATF cooler for the period of turning on of the blocking coupling is put. If there is an overheat, TCM develops the special command for shutdown of blocking of the hydrotransformer for the purpose of restoration of intensity of circulation of ATF via the cooler heat exchanger.
Purpose of the AT separate executive elements
Card of operation of the AT actuation mechanisms
The map is presented in the table.
|
Device |
Ø/m C. And |
Ø/m C. In |
O/D friction clutch |
Friction clutch of forward transfers |
|
|
Р |
•
|
—
|
•
|
—
|
|
|
R |
•
|
—
|
•
|
—
|
|
|
N |
•
|
—
|
•
|
—
|
|
|
D |
1st transfer |
•
|
—
|
•
|
•
|
|
2nd transfer |
•
|
•
|
•
|
•
|
|
|
3rd transfer |
—
|
•
|
•
|
•
|
|
| O/D |
—
|
—
|
—
|
•
|
|
| 2 | 1st transfer |
•
|
—
|
•
|
•
|
| 2nd transfer |
•
|
•
|
•
|
•
|
|
| L | 1st transfer |
•
|
—
|
•
|
•
|
|
Device |
Friction clutch of direct perception |
O/D brake |
Brake of the mode "2" |
Brake of transfers from the 2nd above |
|
|
Р |
—
|
—
|
—
|
—
|
|
|
R |
•
|
—
|
—
|
—
|
|
|
N |
—
|
—
|
—
|
—
|
|
|
D |
1st transfer |
—
|
—
|
—
|
—
|
|
2nd transfer |
—
|
—
|
—
|
•
|
|
|
3rd transfer |
•
|
—
|
—
|
•
|
|
| O/D |
•
|
•
|
—
|
•
|
|
| 2 | 1st transfer |
—
|
—
|
—
|
—
|
| 2nd transfer |
—
|
—
|
•
|
•
|
|
| L | 1st transfer |
—
|
—
|
—
|
—
|
|
Device |
Brake of the L and R modes |
Обг. O/D coupling |
Обг. coupling No. 1 |
Обг. coupling No. 2 | ||
| Vnutr. piston | Plank beds. piston | |||||
|
Р |
—
|
—
|
•
|
—
|
—
|
|
|
R |
•
|
•
|
•
|
—
|
—
|
|
|
N |
—
|
—
|
•
|
—
|
—
|
|
|
D |
1st transfer |
—
|
—
|
•
|
—
|
•
|
|
2nd transfer |
—
|
—
|
•
|
•
|
—
|
|
|
3rd transfer |
—
|
—
|
•
|
—
|
—
|
|
| O/D |
—
|
—
|
•
|
—
|
—
|
|
| 2 | 1st transfer |
—
|
—
|
•
|
—
|
•
|
| 2nd transfer |
—
|
—
|
•
|
—
|
—
|
|
| L | 1st transfer |
•
|
•
|
•
|
—
|
—
|
Friction clutches
General information
Friction clutches consist of a set of ring plates and frictional disks and the executive piston placed in the case (it).
At the released piston frictional disks rotate in the assembly case freely, and gaps between them and ring plates are filled with transmission liquid. When giving on the plate pressure piston densely nestle on disks, forming the monolithic block. ATF is forced out from gaps and under the influence of centrifugal force via the channels which are specially provided in the friction clutch case is taken away in AT case pallet. Otpuskaniye of the piston at removal of pressure occurs under the influence of returnable springs.
|
|
1 — the Ring plate 2 — the Frictional disk 3 — the Returnable spring 4 — the Piston 5 — the Case |
Friction clutch of the raising transfer (O/D)
Provides blocking of a solar gear wheel with the holder of satellites (vodily) of forward planetary assembly.
The friction clutch is involved in all AT modes on all transfers, except raising and, due to blocking of planetary assembly, provides torque transmission from an entrance shaft of O/D in transmission assembly. The special, built-in in the executive piston of a friction clutch, control ball provides deduction of pressure in the included state and its dumping at shutdown. The thin lock ring is used for fixing of all except one disks of a friction clutch, the second lock ring fixes a nave of a disk brake of O/D.
Friction clutch of forward transfers
Provides a joint of the entrance shaft with an intermediate shaft of transmission.
The friction clutch is involved in all AT modes on all transfers of the forward course and, through the nave, provides torque transmission to the intermediate shaft jointed with vodily back planetary assembly. The special, built-in in the executive piston of a friction clutch, control ball provides deduction of pressure in the included state and its dumping at shutdown. The thin lock ring is used for fixing of all except one disks of a friction clutch, the second lock ring fixes the nave of a friction clutch of direct perception rotating thus together with the case of a friction clutch of forward transfers.
Friction clutch of direct perception
Provides a joint of an entrance shaft of a friction clutch of forward transfers with a solar gear wheel.
The friction clutch is involved on the reverse gear, and also on the 3rd and 4th transfers in the R and D modes respectively and provides torque transmission from the nave to a solar gear wheel of back planetary assembly. The nave of a friction clutch of direct perception rotates together with the case of a friction clutch of forward transfers, thus, at simultaneous activation of both friction clutches direct (direct) torque transmission is provided. When only the friction clutch of direct perception is involved, the case of a friction clutch of forward transfers continues to rotate, without transferring at the same time torque to an intermediate shaft. The special, built-in in the executive piston of a friction clutch, control ball provides deduction of pressure in the included state and its dumping at shutdown.
Disk brake assemblies
The design of multidisk brake assemblies is similar to a design of friction clutches.
Disk brake of the raising transfer (O/D)
Blocks rotation of a solar gear wheel of forward planetary assembly.
Brake disks (have internal gearing) are put on vents of a nave, plates (have external gearing) are jointed by vents with the case of brake assembly, pribolchenny to AT case. The nave of a brake is connected directly to a solar gear wheel of forward planetary assembly and at inclusion of the 4th transfer in the D mode of transmission is blocked with the case of brake assembly. The special, built-in in the executive piston of brake assembly, control ball provides deduction of pressure in the included state and its dumping at shutdown. One lock ring is used for fixing of the spring holder, the second lock ring fixes working disks and plates.
Disk brake of the 2 mode
Blocks rotation of a solar gear wheel of back planetary assembly.
The brake is used for ensuring braking with the engine at transfer of transmission to the 2 mode. Disks of a brake are put on vents of the case of a friction clutch of direct perception, plates are jointed by vents with the case of the central support, in turn pribolchenny to a transmission case. At activation of a brake the nave of a friction clutch of direct perception having shlitsevy landing on a solar gear wheel of back planetary assembly is blocked. The special, built-in in the executive piston of brake assembly, control ball provides deduction of pressure in the included state and its dumping at shutdown.
Disk brake of transfers from the 2nd above
Blocks an external holder of the obgonny coupling No. 1, preventing thereby rotation of a solar gear wheel counterclockwise.
Disks of a brake are put on vents of a nave, plates are jointed by vents with the case of the central support, in turn pribolchenny to a transmission case. The brake is involved in the transmission D and 2 modes at the movement on the 2nd, 3rd and 4th (O/D) transfers and its nave at the same time is an external holder for the obgonny coupling No. 1. The special, built-in in the executive piston of brake assembly, control ball provides deduction of pressure in the included state and its dumping at shutdown.
Disk brake of the L and R modes
The holder of satellites blocks (drove) a forward number of back planetary assembly.
Brake assembly has a two-piston design and is located in a back part of a case of AT. Disks of a brake are put on vents of the case of the holder of satellites (drove) a forward planetary row, plates are jointed by vents with a transmission case. In the L and R AT modes the brake provides blocking drove a forward planetary row, and in both cases both pistons are used. The special, built-in in executive pistons of brake assembly, control balls provide deduction of pressure in the included state and its dumping at shutdown.
Obgonny couplings
Obgonny O/D coupling
Serves for a joint of a solar gear wheel with vodily in forward (O/D) to planetary assembly and prevention of their rotation counterclockwise.
The external holder of the coupling is a part drove, internal - a part of a solar gear wheel of forward planetary assembly.
When the solar gear wheel perceives torque from the involved O/D friction clutch, the coupling provides gearing of components with transfer of rotation from the hydrotransformer turbine directly to an entrance shaft of a friction clutch of forward transfers.
At inclusion of the 4th transfer the friction clutch of O/D is switched off and the disk brake of the raising transfer is activated. At the same time the case of a friction clutch and a solar gear wheel of forward (O/D) of planetary assembly are blocked, and the torque of the engine begins to be transferred to the vodil rotating around a solar gear wheel clockwise, at the same time locks of the obgonny coupling are uncoupled, providing freedom of the course drove.
Obgonny coupling No. 1
Serves for prevention of rotation of a solar gear wheel of a planetary row counterclockwise in the reaction time of a disk brake of the 2nd and above transfers at the movement in AT D mode.
The external holder of the coupling is a part of a nave of brake assembly of the 2nd and above transfers, internal - a part of a solar gear wheel of a planetary row.
At the disconnected brake the solar gear wheel rotates counterclockwise as on the 1st and back transfers and locks of the coupling are uncoupled.
Activation of a disk brake of the 2nd and transfers gives to deduction of an external holder of the coupling (a brake nave) above, rotation of a solar gear wheel counterclockwise stops in view of its blocking with a brake nave due to operation of locks of the obgonny coupling.
Obgonny coupling No. 2
Blocks rotation counterclockwise of the holder of satellites (drove) a forward number of back planetary assembly.
The coupling is involved only on the first transfer in AT D and 2 modes, mainly in need of bystry acceleration.
The external holder of the coupling is a part drove a forward number of back planetary assembly, internal - a part of a basic (jet) plate of a disk brake of the L and R modes.
At a start of motion the friction clutch of forward transfers provides the drive of an orbital gear wheel of a back row of planetary assembly that forces a solar gear wheel to rotate counterclockwise. Perception of this rotation vodily a forward planetary row is blocked by locks of the obgonny coupling. As a result, the torque is transferred to an output shaft of transmission only by means of an orbital gear wheel of a forward row.
At the movement on any other transfer of the forward course the solar gear wheel rotates counterclockwise and locks of the obgonny coupling remain uncoupled. At sharp acceleration drove a forward row rotates clockwise, perceiving torque from an output shaft, also providing unhooking of locks of the coupling. At the same time the braking factor is eliminated with the engine.
At the movement in the L mode the brake of the L and R modes blocks rotation drove a forward planetary row, and even gearing of the obgonny coupling No. 2 does not lead to braking inclusion by the engine.
Planetary reducer
|
|
In case of need address the materials stated in the previous subsections. |
Forward planetary assembly (O/D)
Single-row planetary assembly of O/D consists of the solar gear wheel, a set fixed in the holder (drove) satellites and an orbital gear wheel.
The entrance shaft of O/D constantly rotates clockwise, perceiving torque from the turbine of the hydrotransformer jointed with vodily planetary assembly. The drive of a solar gear wheel is carried out by O/D friction clutch involved in all modes and on all transfers except raising.
From an entrance shaft rotation is transferred to satellites of planetary assembly, forcing them to rotate counterclockwise. Friction clutches of O/D and forward transfers are connected to driving wheels of the car. The external holder of the obgonny O/D coupling rotates clockwise, perceiving torque from drove planetary assembly of the raising transfer. Resistance of a solar gear wheel and effort developed vodily leads to blocking of locks of the obgonny coupling and, as a result, a joint of these components with each other, the monolithic block "solar gear wheel-drove-a entrance shaft" is as a result formed. At rotation of a solar gear wheel with an entrance shaft satellites are blocked in an orbital gear wheel that leads to torque transmission to an entrance gear wheel of a friction clutch of forward transfers.
In need of inclusion of the raising transfer the friction clutch of O/D is released and the disk brake of the raising transfer blocking a solar gear wheel around which begins to rotate is involved drove, O/D promoted by an entrance shaft. Satellites are forced to run all over a solar gear wheel, forcing an orbital gear wheel to rotate with bigger, than own (satellites) angular speed. As a result of operation of the described scheme the transfer relation of the raising transfer is formed (0.730: 1).
Back planetary assembly
In the considered AT (AW372LE) the back planetary assembly of a design of Simpson consisting of two planetary rows (satellites in drove also an orbital gear wheel) put on the general solar gear wheel is used.
The solar gear wheel is put on vents of a nave of a friction clutch of direct perception. Drove a forward planetary row by means of shlits it is jointed with brake assembly of the L and R modes and the obgonny coupling No. 1. The orbital gear wheel of a back planetary row is given to rotation by a friction clutch of forward transfers. Back drove also an orbital gear wheel of a forward row, have shlitsevy landing on day off to a shaft.
The required transfer relation is reached at the expense of a combination of blocking of components of a reducer.
Mechanism of parking blocking
The external surface of an orbital gear wheel of a forward planetary row has gear structure, - at transfer of the lever of the selector to situation "P" the special rod equipped with a cam provides deployment of the blocking lever with input of its working ledge in gearing with teeths on an external surface of a gear wheel that leads to blocking of an output shaft of transmission. In any other position of the lever of the selector the output shaft remains free.
|
|
1 — the Orbital gear wheel of a forward number of back planetary assembly 2 — the Cam 3 — the Blocking lever |
Pump station
The hydraulic pressure used at management of functioning of AT is forced in system by the special pump station. Though the rotor of the converter of rotation can also be considered as some kind of pump, generated by it a stream of hydraulic liquid it is consumed exclusively actually by the hydrotransformer, without taking part in functioning of other components of transmission in any way. Liquid arrives on an entrance of the converter and is produced from it not due to functioning of own pump (rotor), and being forced by the special oil pump.
From an exit of the ATF oil pump comes to the special regulator which is responsible for maintenance of working pressure in a path at the constant level. Control of functioning of transmission is exercised by means of various hydraulic lines. On a case of AT it is provided several gates allowing to make measurements of pressure in lines for the purpose of check of serviceability of functioning of transmission in various conditions. At the same time it is worth to remember that pressure in all these control lines is forced only by the AT pump station.
On the considered models the volume oil pump of gear type which drive is carried out directly from a rotation converter nave on which vents the leading gear wheel of pump assembly is put is used.
The principle of functioning transmission pump stations is in detail considered in the Management 179 ("Automatic transmissions of modern cars") ARUS publishing houses.