FR2658880A1 - DEVICE FOR TRANSMITTING A MOTOR TORQUE FROM A MOTOR MOTOR TO AUTOMATIC TRANSMISSION WITH ABSORPTION OF TORSION VIBRATION. - Google Patents

Abstract

This torque transmission device for an automatic transmission mechanism comprises a viscous coupling (1) interposed between the crankshaft (2) of the engine and the housing (4) of the torque converter (3). This viscous coupling effectively dampens the torsional vibrations emitted by the crankshaft by the effect of its viscosity.

Description

The present invention relates to a device

  tif torque transmission for an automatic transmission

  The invention relates to a motor vehicle

  more particularly to a transmission device

  torque which is able to absorb the torsional vibration induced by the fluctuations of the output

of an engine.

  In recent years, it has been expanded

  developed and proposed a torque transmission system.

  be an internal combustion engine for automobiles and an automatic transmission torque converter which

  absorbs the shocks induced by fluctuations in

  engine torque This torque transmission device

  uses a torsion damper interposed between the

  the crankshaft, which constitutes the output member of the internal combustion engine, and the converter housing, which

  is the input element of the torque converter.

  An example of this type of torque transmission device has been described in the Japanese utility model

  first publication 58-79156 (not reviewed).

  As they are, the transmission devices

  previously proposed couples are not fully

  satisfactory in terms of depreciation

  torsional vibrations that are induced on the city

  More particularly, the torsional vibration generated on the crankshaft influences the vibration of the vehicle body and the noise of the vehicle interior when the automatic transmission is working.

  in the blocked mode, in which the crankshaft is

  pleated directly and mechanically to the input shaft of

  the transmission The transmission of the vibration of tor-

  the crankshaft to the transmission may cause

  vibration and an unpleasant noise from the body of the vehicle

  as well as generating noise harmful to the comfort of

vehicle running.

  An object of the present invention is therefore to

  a torque transmission device for an automatic transmission that is capable of suppressing

  the transmission of the torsional vibration of the crankshaft

quin to the casing of the converter.

  To achieve the above goal as well as

  the torque transmission device for trans-

  automatic mission according to the invention uses an accou-

  viscous mixture interposed between the crankshaft and the

  Torque converter housing The coupling

  which effectively damps the entry of

  torsional vibrations of the crankshaft.

  According to one aspect of the invention, a device

  torque transmission for automatic transmission

  that includes: an output shaft of the motor driven by the output torque of the motor; an input element of the torque converter

  of the automatic transmission, which is driven

  the output torque of the motor which is transmitted to it

  set; and a fluid damper interposed between the output shaft of the motor and the input member for connecting

  these bodies to each other, the fluid damper generates

  a damping force in response to a displacement

  relative angular relationship between the motor output shaft

and the input element.

  In the preferred embodiment, the amorphous

  fluid weaver may be constituted by a hydrodynamic damper comprising a movable element connected to one of the two members constituted by the output shaft

  the engine and the input element and which is moving

  depending on the relative angular displacement between the output shaft of the motor and the input element, and hydrodynamic means which generate a resistance opposing the movement of the moving element In this case, the hydrodynamic damper can be constituted by a cylindrical damper body fixed to the output shaft of the engine, which damper body is filled with a working fluid, the movable element comprising a piston disposed in the interior volume of the body of the damper to divide this interior volume into two

  chambers, and a piston rod connected to the element

Tree.

  The input element can be the housing of the con-

torque converter.

  The body of the damper can be filled with

  gas and a hydraulic working fluid, the gas

  to absorb fluctuations in internal pressure.

  of the body of the damper which are due to the varia-

temperature.

  The torque transmission device may further comprise a mechanical spring which cooperates with the fluid damper to exert a resistance

  opposing the relative angular displacement between the

  motor output and the input element.

  In the variation of embodiment, the fluid damper comprises a viscous damper which generates by viscosity a resistance opposing the relative displacement between the output shaft of the motor and the input element In such a case, the damper viscous material may comprise a first rotary element rigidly connected to one of the two members constituted by the output shaft of the motor and by the input element and which defines a

  viscous fluid chamber extending circumferentially

  and filled with a viscous fluid, and a second

  rotary ganes rigidly connected to the other of the elements consisting of the motor output shaft and the input member and having a section disposed therein

  of the viscous fluid chamber to describe a displacement

  angular relative to the viscous fluid chamber, the viscous fluid generating by viscosity

  a resistance that opposes the angular displacement

  latif between the output shaft of the motor and the input element Preferably, the section of the second element

  rotary array carries a plurality of axially extending ribs

  and the viscous fluid chamber includes a plurality of

  grooves designed to receive the ribs with a very small clearance between the surfaces facing the

ribs and grooves.

  As in the first case, the torque transmission device may further comprise a

  mechanical spring which cooperates with the fluid damper

  to counter a relative angular displacement resistance between the output shaft of the motor and the input member In this case, the first rotary member and the section of the second rotary member cooperates to define a plurality of spring housing chambers. which are respectively adapted to receive the components

mechanical spring.

  Other features and advantages of the

  will be better understood when reading the description of

  following example of an embodiment and with reference to the accompanying drawings in which:

  Figure 1 is a section of the main par-

  part of the preferred embodiment of a torque transmission device for automatic transmission according to the invention; Figure 2 is a section taken along the line A-A of Figure 3; and Fig. 3 is a front elevation section of the main portion of another embodiment of the

  torque transmission device according to the invention.

  As can be seen by referring now to

  the drawings and in particular in Figure 1, the

  me preferred to realize a transmission device

  torque for an automatic transmission is

  used to transmit the output torque of the shaft 2 of

  the engine, that is to say the crankshaft, to a

  torque converter 3 The transmission device of

  torque includes a hydrodynamic vibration damper

  1 interposed between the output shaft 2 of the motor and the housing 4 of the torque converter 3, to establish the connection between these bodies The vibration damper

  hydrodynamic 1 comprises a hollow cylinder 5

  5 is filled with a viscous working fluid and a gas The gas is contained in the hollow cylinder to absorb the variations of the pressure of the hollow cylinder which result from the temperature A piston 6 is disposed in the interior volume of the cylinder hollow 5 to define two fluid chambers insulated from each other The piston 6 is provided with axial orifices 15 which allow the fluid to circulate at a limited flow rate between the

  isolated chambers formed in the hollow cylinder

  flow rate that occurs at orifices

  axial dimensions can be determined according to the characteristics

  vibration damping ticks we want to get

  in the hydrodynamic vibration damper 1

  piston 7 is connected to the piston 6 to describe a

  translational movement with this piston The rod of pistons

  your 7 passes through the hollow cylinder 5 A helicoidal spring

  dal 8 is disposed in the hollow cylinder 5 The spring 8 is pressed against the piston 6 at one end and at the other end it is pressed against a spring seat 9 provided in the vicinity of the axial end of the cylinder hollow, through which the piston rod passes, to tend to urge the piston 6 with the piston rod 7 A seal 10 is provided between

  the axial end of the hollow cylinder and the range of

  fate 9 to establish a fluid tight seal while

  allowing the translation movement of the piston rod

your 7.

  The piston rod 7 of the vibration damper

  hydrodynamic 1 has at its outer extremity

  Part 11 in the form of a loop Part 11 in form

  The other end of the hollow cylinder 5 of the hydrodynamic vibration damper 1 is mounted on the axial end of the output shaft 2 of the engine. through a tab 13 which is rigidly fixed to the axial end of the shaft of

  motor output by a fixing screw 14.

  The casing 4 of the converter has a tip

  bearing shaft 16 which journalled in the axial end

  the output shaft 2 of the motor On the other hand, the

  converter housing 4 contains in its

  a clutch locking mechanism 17, a unit

  hydrodynamic torque converter 18, etc. Ain-

  if it is well known, the clutch mechanism of

  cage 17 is connected to a turbine hub 20 by means of a link

  sound that allows axial displacement

  clutch Pl and a clutch chamber P 2 are set on both sides of the clutch locking mechanism

  17 to establish and selectively suppress the state of

  locking clutch cage The introduction and de-

  load of the line pressure in the clutch chamber

  ge P1 and the clutch chamber P 2 are controlled in a manner known per se according to the conditions of

  vehicle operation More specifically, when

  pre-determined blocking conditions, for example

  when the speed of the vehicle becomes greater than a predetermined blocking criterion, the line pressure is introduced into the clutch chamber to engage the locking clutch Under the effect of the clutch of the locking clutch, the output shaft 2 of the motor

  is coupled directly or mechanically to the drive shaft

  19 of a transmission (not shown).

  re, if the predetermined blocking condition is not satisfied, the line pressure is introduced into the

  disengagement chamber to maintain the blocking clutch

  in the disengaged state In such a case, the convert

  torque converter works in its converter mode to transmit the input torque of output shaft 2 of the motor to the input shaft 19 of the transmission by

the hydrodynamic channel.

  Furthermore, there is provided a drive plate 21 which carries a ring gear 22 The plateau

  21 is connected to the output shaft 2 of the

  By means of a hydrodynamic vibration damper 1 On the other hand, the ring gear 22

  is engaged with the gear of a starter (not shown

té) for engine launch.

  At the beginning of the engine launching action, the output shaft 2 of the motor is rotated

  by a drive torque input resulting from the start

  through the crown 22 and the

  If a starter drive torque is transmitted to the output shaft 2 of the motor while the torque converter 3 is in an inactive state, the result is a relative angular displacement between the output shaft. 2 of the engine and the housing 4 of the torque converter 3 The piston 6 of the hydrodynamic vibration damper 1 is then driven outwards, with the piston rod 7, against the elastic force of the coil spring 8 Under the effect of the piston movement, the working fluid contained

  in one of the fluid chambers is compressed to generate

  Because of this, a fluid flow occurs through the axial orifices 15 Since the flow of the fluid is throttled by the orifices 15, a force of hydrodynamic damping, which exerts its action together with the elastic force

  of the coil spring 8, to resist the relative movement

  latif between the output shaft 2 of the engine and the casing 4

  In this way, the impact produced in

  purpose of the engine launch action can be absorbed successfully, to transmit the drive torque

  to the casing 4 of the converter without jerks.

  Hydrodynamic vibration damper 1 a

  also to absorb the torsional vibration

  This is because, just as at the moment of the engine launching action, the torsional vibration of the output shaft 2 of the motor causes a relative angular displacement between the engine and the engine. motor output shaft and the converter housing 4 In the same way that it has been described more

  high, the hydrodynamic vibration dampener 1 engen-

  then a damping force formed of a combination of

  the hydrodynamic force generated by foreign

  flow at the orifice 15, and

  the elastic force of the coil spring 8.

  The output torque of the motor can therefore be transmitted smoothly to the converter housing 4 by

  the hydrodynamic vibration damper

  1 The vibration that would be transmitted to the cash register

  of the vehicle can therefore be deleted to an extent

  satisfactory, thus reducing the vibrations and

sounds of the vehicle body.

  In the embodiment shown, the hydrodynamic vibration damper 1 encloses a

  viscous fluid and a gas However, while the

  is driven, the centrifugal force acts on the fluid

  working to push the working fluid to the outside The gas contained in the cylinder 5 is for this reason placed inside The gas is therefore at risk

  not be left in the compression stroke of the piston

  6 The presence of the gas is therefore not likely to affect the vibration damping performance of

  the hydrodynamic vibration damper.

  Although the embodiment shown

  uses a particular type of amortization